Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • ZIB Catalog
  • Articles: DFG German National Licenses  (6,313)
  • Opus Repository ZIB
  • 1990-1994  (1,990)
  • 1965-1969  (2,339)
  • 1955-1959  (991)
  • 1940-1944  (182)
  • 1930-1934
  • 1905-1909
  • 1900-1904  (450)
  • 1890-1899  (361)
  • 1992  (1,990)
  • 1969  (1,098)
  • 1968  (1,241)
  • 1959  (434)
  • 1956  (557)
  • 1942  (182)
  • 1902  (450)
  • 1895  (155)
  • 1891  (206)
  • General Chemistry  (5,473)
  • Engineering  (789)
  • Kidney
Source
  • ZIB Catalog
  • Articles: DFG German National Licenses  (6,313)
  • Opus Repository ZIB
Material
Years
  • 1990-1994  (1,990)
  • 1965-1969  (2,339)
  • 1955-1959  (991)
  • 1940-1944  (182)
  • 1930-1934
    • +
Year
Keywords
  • 1
    Electronic Resource
    Electronic Resource
    The glomerular mesangium: capillary support function and its failure under experimental conditions (1992)
    Springer
    Journal of molecular medicine 70 (1992), S. 843-856 
    Details
    ISSN: 1432-1440
    Keywords: Kidney ; Glomerulus ; Mesangium ; Mesangial failure ; Electron microscopy ; Animal models
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary We present a structural analysis of the ability of the biomechanical unit consisting of mesangium and glomerular basement membrane to maintain normal capillary architecture in the face of mechanical challenges due to high intraglomerular pressures. Capillary support function may be considered in terms of the stabilization of local form (development of wall tension against capillary dilation) and global form (centripetal fixation of capillary loops to maintain higher order form). The pathologic consequences of the loss of this support are illustrated by way of experimental models of mechanical mesangial failure. Such failure may express itself as mesangial widening, increased transmesangial macromolecule “traffic,” ballooning of capillary segments, and unfolding of capillary loops. Mechanisms are described by which these structural changes may lead to segmental glomerular sclerosis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00180755
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Carvedilol and the kidney (1992)
    Springer
    Journal of molecular medicine 70 (1992), S. S127 
    Details
    ISSN: 1432-1440
    Keywords: Carvedilol ; Kidney ; Hypertension ; Renal hemodynamics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Antihypertensive drugs have differing effects on renal hemodynamics, tubular function, plasma electrolytes, and hormonal responses. Nonselective β-blockers without intrinsic sympathomimetic activites, such as propranolol, have been reported to reduce renal blood flow and to cause a modest decrease in glomerular filtration rate. Carvedilol is a new multiple action agent displaying nonselective β-blockade without intrinsic sympathicomimetic activity, α1-adrenoceptor blockade (probably responsible for its vasodilator activity), and possibly also calcium antagonist properties. The presence of these different pharmacodynamic properties results in a different effect on the kidney as compared with, e.g., propranolol. In the dog, intrarenal infusion of carvedilol resulted in a renal vasodilator response with preservation of renal blood flow and without inducing sodium retention; in contrast, propranolol induced a renal vasoconstrictor response and sodium retention in this model. A renal vasodilator response to carvedilol was also reported in spontaneously hypertensive rats (SHR) and in DOCA-salt SHR. In contrast to labetalol, i.v. infusion of hypotensive doses of carvedilol in conscious SHR did not cause sodium retention. Carvedilol was effective in controlling hypertension and preserving renal function in a rat model of progressive hypertensive renal disease. In patients with essential hypertension, carvedilol was reported to reduce renal vascular resistance in the presence of reduced perfusion pressure, allowing for normal renal autoregulation of renal blood flow. Although a small reduction in glomerular filtration rate was seen after acute administration, renal function was preserved during chronic treatment. It is concluded from these studies that renal perfusion and renal function are well maintained during acute and chronic treatment with carvedilol. The compound does not appear to cause sodium retention, and preliminary animal test data suggest the possibility of a renoprotective effect.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00207623
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Renal potassium bicarbonate release in humans exposed to an acute volume load (1992)
    Springer
    Journal of molecular medicine 70 (1992), S. 692-697 
    Details
    ISSN: 1432-1440
    Keywords: Kidney ; Urine concentration ; Volume regulation ; Potassium ; Bicarbonate ; Aldosterone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Cells of the renal medulla regulate their volume by transmembrane ion movements when exposed to large changes in osmolality. Since renal cells in culture release KHCO3 in response to hypotonic stress [11], we investigated the effect of an acute water load on urinary KHCO3 excretion in 5 healthy individuals. Water diuresis was induced by the ingestion of 1.51 hypoosmolal fluid (22 mosm/kg H2O) over 15 min. The rate of urinary volume excretion increased from an initial value of 1.4 ml/min to 9.3 ml/min after 75 min. Urinary osmolality dropped from an initial value of 940±32 mosm/kg H2O to 74±4 mosm/kg H2O (n = 5). The decrease of osmolality was accompanied by the transient release of potassium and bicarbonate. Peak values of KHCO3 excretion were observed between 30 and 45 min after the onset of the experiment corresponding to the drop of urinary osmolality. The magnitude of renal potassium release correlated significantly (r=0.93; P 〈 0.05) with endogenous plasma aldosterone concentrations measured prior to the experiment in the 5 volunteers. We conclude that medullary epithelial cells release KHCO3 when exposed to hypotonic stress. The volume regulatory response is upregulated by aldosterone.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00180288
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Caries susceptibility and renal excretion of calcium (1992)
    Springer
    Journal of molecular medicine 70 (1992), S. 735-739 
    Details
    ISSN: 1432-1440
    Keywords: Kidney ; Calcium ; Phosphate ; Sodium ; Caries
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Clearance studies were performed for 2 days in two groups of age-matched young female volunteers: those with low caries prevalence and those with high caries prevalence. Both groups were kept on a low-calcium diet for 1 week and received 0.5 g calcium at the beginning of the second day. In both groups, glomerular filtration rate, urinary flow rate and renal excretions of sodium, calcium, and phosphate were subject to significant circadian variations. In both groups the administration of calcium led to a significant increase in renal excretion of sodium and calcium and a significant decrease in that of phosphate. On the first day, calcium excretion was significantly greater in those with low caries prevalence than in those with high caries prevalence, pointing to altered calcium homeostasis in this group.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00180739
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Activation of β2-adrenoceptors by isoprenaline and adrenaline enhances noradrenaline release in cortical kidney slices of young spontaneously hypertensive rats (1992)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 345 (1992), S. 25-32 
    Details
    ISSN: 1432-1912
    Keywords: 3H-noradrenaline release ; SHR ; Kidney ; Prejunctional β-adrenoceptors ; Adrenaline ; Isoprenaline ; cAMP
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The aim of the present study was to investigate β-adrenoceptor modulation of noradrenaline release from sympathetic nerves in superfused cortical kidney slices of 4-week-old spontaneously hypertensive rats (SHR) and age-matched controls (WKY). After preincubation with 3H-noradrenaline the kidney slices were electrically stimulated in superfusion chambers. The stimulation induced (S-I) outflow of radioactivity was mainly composed of unmetabolized 3H-noradrenaline in both strains and thus taken as an index of noradrenaline release. There was a frequency-dependent (1.25–20 Hz) increase in the S-1 outflow of radioactivity. At all stimulation frequencies tested S-I outflow of radioactivity was similar or even slightly lower in SHR than in WKY kidney slices in either the absence or presence of cocaine (10 μmol/l). The non-selective β-adrenoceptor agonists isoprenaline (0.l gmol/1) and adrenaline (0.01 and 0.1 μmol/l) enhanced S-I outflow of radioactivity. The facilitatory effects of isoprenaline (0.1 μmol/l) and adrenaline (0.1 μmol/l) were blocked by the selective β2-adrenoceptor antagonist ICI 118551 (0.1 μmol/l) but not by the selective β1-adrenoceptor antagonist atenolol (0.3 μmol/l). The cell-permeable CAMP analogue 8-bromo-cAMP (300 μmol/l) enhanced S-1 outflow of radioactivity to a similar extent in both SHR and WKY kidney slices. A combination of 8-bromo-cAMP (300 μmol/l) and adrenaline (0.1 μmol/l) did not enhance S-1 outflow of radioactivity to a greater extent than 8-bromo cAMP (300 μmol/l) alone in both strains. However, the facilitatory effects of isoprenaline (0.1 μmol/l) and adrenaline (0.1 μmol/l) but not that of adrenaline (0.01 μmol/l) were significantly greater in SHR than in WKY. The results suggest that stimulation of prejunctional β2-adrenoceptors by adrenaline even in the absence of a-adrenoceptor blockade enhances noradrenaline release in kidney cortex of young SHR and WKY. This β2-adrenoceptor mediated effect may possibly be dependent on cAMP formation. The greater facilitatory effects of isoprenaline (0.1 μmol/l) and adrenaline (0.1 μmol/l) in SHR as compared to WKY are in accord with receptor binding studies which show a higher density of β2-adrenoceptors in SHR than in WKY kidney cortex.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00175465
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Influence of antihypertensive therapy on renal function (1992)
    Springer
    Journal of molecular medicine 70 (1992), S. S120 
    Details
    ISSN: 1432-1440
    Keywords: Hypertension ; Kidney ; Antihypertensive drugs
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Antihypertensive therapy influences kidney function by different mechanisms depending on the mode of action of the drug used. The GFR is improved by calcium entry blockers and ACE inhibitors, unaffected by vasodilators, α-blockers and centrally acting sympatholytics and impaired by β-blockers. The same is true for renal blood flow and is due to changes of renal vascular resistance. Renal sodium excretion is impaired mostly by vasodilators, by α-blockers, sympatholytics and β-blockers; in contrast, calcium entry blockers and ACE inhibitors acutely induce natriuresis. The RAAS is stimulated by vasodilators, unaffected by α-blockers and sympatholytics and suppressed by β-blockers. Plasma catecholamines are stimulated by vasodilators and suppressed by centrally acting sympatholytics and unaffected by the others. Induction of acute renal functional impairment is reported for ACE inhibitors under conditions of compromised renal perfusion pressure such as in renal artery stenosis. These data from the literature reviewed are supported by our own experimental data on sodium balance under different drugs and micropuncture data in experimental renal artery stenosis. To achieve effective antihypertensive treatment with a low profile of side effects, careful monitoring of renal function seems to be mandatory.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00207622
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Ca2+ uptake by endoplasmic reticulum of renal cortex. II. Effects of uninephrectomy and parathyroidectomy (1992)
    Springer
    Calcified tissue international 51 (1992), S. 42-47 
    Details
    ISSN: 1432-0827
    Keywords: Kidney ; Endoplasmic reticulum ; Calcium ; In vivo
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Calcium uptake by the endoplasmic reticulum (ER) is important for cellular calcium homeostasis, yet its regulation in nonmuscle cells is poorly understood. We reported that Ca2+ uptake by a light fraction of canine renal cortical ER (LER) is stimulated by protein kinase C in vitro. Here we describe conditions in vivo that stimulated renal cortical LER Ca2+ uptake. Thirty minutes after contralateral nephrectomy in the dog, 45Ca2+ uptake into renal cortical LER was increased 42% above control LER. There was no difference in LER Ca2+ uptake 24 hours after uninephrectomy. Acute denervation did not reproduce the increase in LER 45Ca2+ uptake seen at 30 minutes after uninephrectomy, nor did prior thyroparathyroidectomy abolish it. Forty-eight hours after thyroparathyroidectomy, 45Ca2+ uptake activity into renal cortical LER was decreased ≈sevenfold. In a proximal tubular cell line (LLC-PK1), 30-minute incubation with 12-O-tetradecanoylphorbol-13-acetate doubled 45Ca2+ uptake into a nonmitochondrial pool. Pretreatment with epidermal growth factor halved ER Ca2+ uptake, whereas insulin-like growth factor and growth hormone, alone or in combination, had no effect. Our data suggest that Ca2+ uptake into renal cortical ER is stimulated acutely during compensatory renal growth, perhaps through protein kinase C, and is stimulated chronically by parathyroid hormone.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00296216
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Arteries and veins formed within renal vessels: a previously neglected observation (1992)
    Springer
    Virchows Archiv 420 (1992), S. 301-304 
    Details
    ISSN: 1432-2307
    Keywords: Kidney ; Blood vessels ; Arterialisation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary An abnormality of blood vessels was noted in a biopsy of a renal transplant. This took the form of apparent development of a new artery inside and concentric with the old, with elastic laminae and a muscular media, separated from the old internal elastic lamina by poorly cellular tissue. In a systematic study of material from another 119 renal transplants, 13 nephrectomy specimens for chronic pyelonephritis and hydronephrosis, 28 renal biopsies showing interstitial nephritis, and 18 renal biopsies showing small vessel vasculopathy of accelerated hypertensive type, similar arterial changes were seen in another 10 renal transplants that showed chronic vascular rejection, 1 case of chronic interstitial nephritis, and 3 cases of vasculopathy, 2 with accelerated hypertension and 1 with systemic sclerosis. One renal transplant also showed apparent development of new muscular veins inside old veins. Immunohistological study for smooth muscle actin confirmed that the apparently new arterial and venous structures contained smooth muscle cells. The arterial abnormality may be called arterialisation of intrarenal arteries. This change appears to be not rare, is distinctive, and has scarcely been previously recognised or reported as a response of intrarenal blood vessels to damage.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01600208
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    The renin-secreting cell and the glomerular peripolar cell in renal artery stenosis and Addison's disease (1992)
    Springer
    Virchows Archiv 420 (1992), S. 533-537 
    Details
    ISSN: 1432-2307
    Keywords: Peripolar cell ; Renin ; Juxtaglomerular apparatus ; Kidney
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The glomerular peripolar cell may be a secretory component of the juxtaglomerular apparatus. To investigate this hypothesis we studied kidneys with the renin-angiotensin system activated by two different stimuli in order to compare the responses of peripolar cells and renin-secreting cells. We examined 10 human kidneys, removed for renal artery stenosis and 11 autopsy cases of Addison's disease with appropriate controls. We counted granulated peripolar cells in serial paraffin-embedded sections and renin-containing cells were quantified using an immunoperoxidase technique with an antiserum to human renin. There was a five-fold increase in the number of renin-containing cells in both renal artery stenosis and in untreated, but not in treated, Addison's disease. Peripolar cells were increased in number in three cases of renal artery stenosis, but were unaltered in both treated and untreated Addison's disease. Therefore, neither a reduction in renal perfusion pressure (renal artery stenosis), nor sodium depletion (Addison's disease) consistently affect peripolar cells in humans. These findings do not support the hypothesis that the peripolar cell is part of the juxtaglomerular apparatus.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01600259
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Analysis of kidney volume growth during the fetal period in humans (1992)
    Springer
    Urological research 20 (1992), S. 271-274 
    Details
    ISSN: 1434-0879
    Keywords: Kidney ; Fetal kidney ; Renal volume ; Renal growth ; Fetal urology ; Renal anomalies
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The growth of fetal kidney volume was studied in 290 specimens taken from 145 fresh human fetuses (85 males and 60 females) with gestational age ranging from 13 to 36 weeks postconception (WPC). Normative equations and curves of the growth of renal volume were obtained for male and female fetuses and for the whole sample in the second trimester (13–24 WPC) and in the third trimester (25–36 WPC) of gestation. There was no difference between the growth in volume of the right and left kidneys. Fetal kidney volume increases with a more intense rhythm in the early fetal period (13–24 WPC). During the second trimester, there was no difference between the values for renal volume of male and female fetuses. In the third trimester, male fetuses had renal volumes significantly greater than the female fetuses. The normative parameters of renal volume could have practical applications in detection and monitoring of renal anomalies in fetal and perinatal urology.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00300257
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 11
    Electronic Resource
    Electronic Resource
    Effect and distribution of intravenously injected 125I-endothelin-1 in rat kidney and lung examined by electron microscopic radioautography (1992)
    Springer
    Anatomy and embryology 185 (1992), S. 87-96 
    Details
    ISSN: 1432-0568
    Keywords: Kidney ; Endothelium ; Glomerular mesangium ; Lung ; Autoradiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The morphological effect of endothelin-1 (ET-1) and the distribution of endothelin-binding sites on the kidney and lung was investigated ultrastructually by intravenous injection of [125I]-ET-1 into rats. About 10% decrease of the diameter of glomeruli was observed at 10 min after the injections of ET-1 or [125I]-ET-1 (1.3–2.4 nmole/kg). When localization of [125I]-ET-1 in the kidney was examined by light and electron microscopic radioautography, silver grains were preferably localized on the fenestrated endothelial cells of glomeruli and peritubular capillary endothelial cells. Some grains were also localized on the interdigitating processes of urinary tubules. Quantitative analysis of silver grains in the glomeruli showed that 83% of grains were located on the fenestrated endothelial cells, 12% on the podocytes of visceral cells, and 5% on mesangial cells at 10 min. After 60 min, 50% of silver grains were incorporated into the cytoplasm of fenestrated endothelial cells. In contrast to glomeruli, silver grains were rare on the arteries and large arterioles. However, a few silver grains were often observed on the smooth muscle cells of small arterioles (8–20 μm in diameter). In the lung, 70% of silver grains were located on the alveolar capillary endothelial cells. These results indicate the abundance of ET receptors on the glomerular fenestrated endothelium, peritubular fenestrated endothelium and alveolar capillary endothelium.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00213604
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 12
    Electronic Resource
    Electronic Resource
    Development of the metanephros in the chick: maturation of glomerular size and nephron length (1992)
    Springer
    Anatomy and embryology 185 (1992), S. 291-297 
    Details
    ISSN: 1432-0568
    Keywords: Kidney ; Nephron development ; Chick
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In the avian kidney three nephron types may be identified: mammalian-type nephrons with long (MTN-I) and short (MTN-II) loops of Henlé, and reptilian-type nephrons (RTN). By the method of microdissection the maturation of the nephrons of domestic fowl kidney has been studied. From the 14th day of incubation it is possible to isolate the MTN-I which appear first; all three nephron types may be isolated after 18 days of incubation. The thin limb of Henlé's loop in MTN-I appears after hatching, and the length of this segment in 1-day-old chicks is 0.1–0.13 mm. In 60-day-old chicks its length has approximately doubled. The transition of the thin segment to the thick segment is situated in the descending part of Henlé's loop. In the course of development, the relative length of all nephron segments in MTN-I increases uniformly, while in MTN-II and in RTN the relative length of the proximal and distal convoluted tubules increases. At all stages of development, MTN-I are the longest among the three groups of nephrons and have the largest glomeruli. The comparison between developing avian and mammalian kidneys shows great similarities in the process of maturation in analogous nephron types in these two classes of vertebrates.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00211828
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 13
    Electronic Resource
    Electronic Resource
    Structural relationships between the endothelial actin system and the underlying elastic layer in the distal interlobular artery of the rat kidney (1992)
    Springer
    Anatomy and embryology 186 (1992), S. 467-476 
    Details
    ISSN: 1432-0568
    Keywords: Artery ; Endothelial cell ; Stress fiber ; Elastic fiber ; Kidney
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The structure of the intracellular actin filaments and the extracellular matrices was studied in the distal interlobular arteries in the rat kidney, employing three different morphological techniques, including rhodamin-phalloidin staining of cryosections, resorcin-fuchsin staining of paraffin sections, and a cold dehydration procedure for electron microscopy. The endothelial cells possess longitudinally running stress fibers. The inner elastic layer is composed of meshworks of elastic fibers encompassing numerous pores. The smooth muscle cells containing abundant actin filaments are arranged circumferentially around the vascular axis. The endothelial stress fibers are found mainly in the basal half of the endothelial cells, and anchor onto the basal cell membranes. The elastic meshworks send off longitudinal branch fibers to contact the endothelial cell membranes at the anchoring sites of stress fibers. In addition circumferential branches run toward the smooth muscle cells. The functional significance of the intracellular contractile apparatus and the extracellular tensile component in small arteries was discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00185460
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 14
    Electronic Resource
    Electronic Resource
    Transient increase in renal insulin-like growth factor binding proteins during initial kidney hypertrophy in experimental diabetes in rats (1992)
    Springer
    Diabetologia 35 (1992), S. 589-593 
    Details
    ISSN: 1432-0428
    Keywords: Kidney ; hypertrophy ; insulin-like growth factors ; insulin-like growth factor binding proteins ; streptozotocin ; diabetes ; rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The insulin-like growth factors, insulin-like growth factor I and insulin-like growth factor II are bound to six distinct classes of insulin-like growth factor binding proteins (IGFBPs) in the circulation and in extracellular fluids. Diabetic renal hypertrophy is preceded by a transient increase in kidney insulin-like growth factor I suggestive of a renotropic function for insulin-like growth factor I. In order to examine a possible involvement of IGFBPs in initial diabetic kidney growth and in kidney insulin-like growth factor I accumulation, we studied rat kidney IGFBPs by ligand blotting during the first 4 days after induction of diabetes. Six distinct bands were identified in kidney and liver tissue with apparent molecular weight values of 38–47 (doublet), 34, 30, 24 and 20 kDa. The 38–47 kDa doublet band probably corresponds to the insulin-like growth factor binding subunit of IGFBP-3, the 24 kDa band to IGFBP4 and the 30 kDa band to IGFBP-1 and/or IGFBP-2, as these IGFBPs in rats have similar molecular weight. In untreated diabetic rats a transient increase in the kidney 30 kDa band was demonstrable 24 h after induction of diabetes with a maximal rise (two-fold) after 48 h, followed by a decrease to baseline values after 4 days. In untreated diabetic rats the 38–47 kDa doublet band also increased (two-fold) in kidney during the first 2 days after induction of diabetes, followed by a subsequent decrease. Insulin-treatment prevented both the increase in the 30 kDa and in the 38–47 kDa bands. Kidney weight in untreated diabetic rats increased by 26 % after 4 days. In conclusion, the present study shows a transient increase in the 30 kDa and the 38–47 kDa IGFBP species in hypertrophying diabetic kidneys, contemporarily with the previously described transient increase in extractable kidney insulin-like growth factor I content. These findings support the concept that IGFBPs may be involved in the action of insulin-like growth factor I and possibly in the diabetic kidney insulin-like growth factor I accumulation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00400489
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 15
    Electronic Resource
    Electronic Resource
    Renal arteries: anatomic study for surgical and radiological practice (1992)
    Springer
    Surgical and radiologic anatomy 14 (1992), S. 113-117 
    Details
    ISSN: 1279-8517
    Keywords: Kidney ; Renal artery ; Multiple renal arteries ; Renal transplantation ; Renal angiography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé La vascularisation artérielle du rein a été analysée à partlr de 266 dissections provenant de 133 sujets d'anatomie. Les résultats anatomiques sont les suivants: une seule artère hilaire est présente dans 53,3% des cas; une artère hilaire associée à une branche polalre supérieure extrahilaire dans 14,3% des cas; deux artères hilaires dans 7,9% des cas; trois artères hilaires dans 1,9% des cas; une artère polaire supérieure dans 6,8% des cas; une artère polaire inférieure dans 5,3% des cas; enfin d'autres variations dans 8,5% des cas. Sont envisagées les applications urologiques et radiologiques de ces constatations dans la transplantation rénale, la pathologie hypertensive d'origine rénale, la traumatologie rénale, la radiologie interventionnelle, la chirurgie conservatrice et l'oncologie.
    Notes: Summary The renal arterial supply was analyzed in 266 kidneys dissected from 133 fixed adults subjects. The anatomical findings are presented: 1 hilar artery in 53.3% of the cases, 1 hilar artery with 1 superior pole extra-hilar branch in 14.3%, 2 hilar arteries in 7.9%, 3 hilar arteries in 1.9%, superior polar artery in 6.8%, inferior polar artery in 5.3% and other variations in 8.5%. The urological and radiological implications of these findings in kidney transplantation, renovascular hypertension, renal trauma, interventional radiology, conservative surgery and oncologic surgery are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01794885
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 16
    Electronic Resource
    Electronic Resource
    Ca2+ uptake by endoplasmic reticulum of renal cortex. I. Ionic requirements and regulation in vitro (1992)
    Springer
    Calcified tissue international 51 (1992), S. 35-41 
    Details
    ISSN: 1432-0827
    Keywords: Kidney ; Endoplasmic reticulum ; Calcium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary A subcellular fraction enriched in cytochrome c reductase (7.9-fold) and relatively de-enriched (0.64-fold) in Na+/K+-ATPase was prepared from canine kidney cortex by sucrose density gradient ultracentrifugation. It was shown by electron microscopy to consist primarily of a light fraction of endoplasmic reticulum (LER). LER vesicles displayed ATP-dependent 45Ca2+ uptake that was insensitive to 10 mM KCN or NaN3, and was promptly released by 20 μM A23187 or ionomycin. Inositol-1,4,5-trisphosphate (IP3) appeared to produce a time-dependent release of 45Ca2+. Vanadate inhibited 45Ca2+ uptake with a Ki≈0.3 mM, further suggesting that the activity resided in the ER rather than the plasma membrane. 45Ca2+ uptake by LER, at 5 μM total [Ca2+], displayed a strong dependence on divalent cations (Mg2+〉Co2+〉Mn2+≫Ba2+≥Cd2+≥Sr2+, present at 2 mM) as well as on monovalent cations (Na+≥K++Na+ 〉K+〉Li+〉choline+), and anions (Cl-〉acetate-≥NO3 -≥F-〉H2PO4 -≫gluconate-≥oxalate=≫SO4 =). It had a fairly narrow pH optimum (7.25–7.50). Preincubation (10 min) of LER vesicles with 12-O-tetradecanoylphorbol-13-acetate (TPA) stimulated LER Ca2+ uptake; this effect was enhanced in the presence of renal cytosol [5% (vol/vol)]. However, Ca2+ uptake was not affected by preincubation with dibutyryl cyclic AMP, calmodulin, or 1,25-(OH)2-vitamin D3, either in the absence or presence of renal cytosol. Thus, the Mg2+-ATP dependent 45Ca2+ uptake activity of this canine renal cortical LER fraction displays modulation by IP3, TPA, and pH that appears to be physiologically relevant.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00296215
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 17
    Electronic Resource
    Electronic Resource
    Pharmacokinetics and tolerance of Gd-DOTA (DOTAREM) in healthy volunteers and in patients with chronic renal failure (1992)
    Springer
    European radiology 2 (1992), S. 326-329 
    Details
    ISSN: 1432-1084
    Keywords: Gd-DOTA ; Contrast media ; Kidney ; Renal failure ; Pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The aim of this study was to assess the pharmacokinetics and tolerance of Gd-DOTA (DOTAREM) in non-dialysed patients with chronic renal failure. Eight patients with chronic renal failure (creatinine clearance between 10 and 60 ml/min) and four healthy volunteers were given i.v. Gd-DOTA (0.1 mmol/kg). Blood and urine samples were collected. Gd-DOTA tolerance was also studied (vital signs, biological parameters, adverse reactions). In healthy volunteers, Gd-DOTA was rapidly distributed in the extracellular space and almost totally eliminated in the urine (glomerular filtration, 93.3±4.7% of the dose 24 h post injection). In patients with chronic renal failure, a delayed and almost total urinary elimination observed with a correlation between Gd-DOTA clearance and plasma creatinine clearance (r = 0.964). Tolerance was good with no significant modification of renal function or other parameters. These results confirm previous studies and indicates that DOTAREM can be used safely for patients with chronic renal failure.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00175436
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 18
    Electronic Resource
    Electronic Resource
    Ethical and psychological aspects of living donorship and life with a donated organ (1992)
    Springer
    European journal of pediatrics 151 (1992), S. S76 
    Details
    ISSN: 1432-1076
    Keywords: Ethics ; Psychology ; Living organ transplantation ; Paediatrics ; Kidney
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract There is far-reaching consent in the literature that public and consensual agreements on the basics of the different aspects of medical ethics are inalienable before the instigation of any innovative transplant procedure. In the case of a certain method and/or of an individual patient, however, the ultimate ethical evaluation can most likely never be entirely complete before this application. Ethical evaluation depends on the actual criteria used, the present knowledge regarding the risk-benefit-balance as well as on the ethical evaluation of the patient's and his family's own feelings and expectations which are not entirely conscious. In relation to the so-called “fundamental and constant ethical guidelines” and under a psychological perspective potential, ethical conflict constellations are presented which have to be dealt with in the process of ethical and psychological evaluation before living organ transplantation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02125808
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 19
    Electronic Resource
    Electronic Resource
    Cell proliferation induced in the kidneys and livers of rats and mice by short term exposure to the carcinogen p-dichlorobenzene (1992)
    Springer
    Archives of toxicology 66 (1992), S. 503-507 
    Details
    ISSN: 1432-0738
    Keywords: Kidney ; Liver ; Cell proliferation ; Rat ; Mouse ; p-Dichlorobenzene
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Cell proliferation in the kidneys and livers of rats and mice exposed short-term to p-dichlorobenzene (p-DCB) was evaluated by immunohistochemical measurement of bromodeoxyuridine (BrdU) incorporation into nuclei of DNA-synthesizing cells. p-DCB was given by gavage at two doses up to 600 mg/kg body weight for 4 days. The cumulative fraction of proliferating cells was increased in the proximal tubule epithelial cells of male rats at the high dose, but not at the low dose nor in females at either dose using gamma-glutamyl transferase reaction to identify tubular cells. Also, no increase in cell proliferation was found in mouse kidneys. The fractions of proliferating cells in the livers of rats and mice of both sexes were also increased. The increased cell proliferation in only male rat kidney and in the livers of mice of both sexes correlates with the reported carcinogenic effects of p-DCB in those tissues. However, the finding that p-DCB also induced cell proliferation in the livers of rats of both sexes, which were not a site of p-DCB-induced tumors in bioassays, and in female mice at the low dose, which was not affected by an increase in tumors, reveals a lack of concordance and indicates that acute induction of cell proliferation is not sufficient to lead to carcinogenesis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01970676
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 20
    Electronic Resource
    Electronic Resource
    Renal transplantation in infants, a therapeutic option? (1992)
    Springer
    European journal of pediatrics 151 (1992), S. S13 
    Details
    ISSN: 1432-1076
    Keywords: Kidney ; Transplantation ; Infant ; Uremia ; Development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Renal transplantation is widely accepted as the treatment of choice for endstage renal failure in childhood. Since dialysis is regularly applied to infants with renal failure, the question logically arises, can infants also receive renal transplants and what are the outcomes? A review of the literature and the clinical experience at the University of Minnesota supports the performance of renal transplantation in infancy. Present patient and graft survival rates for infants are indistinguishable from those of older children. While living adult donors are preferred, adult cadaveric kidneys have also been successfully transplanted. Following successful transplantation, the infants have generally enjoyed “catch-up” growth and accelerated psychomotor development. While there may be problems related to fluid and electrolyte balance in these smallest patients, the majority of the problems encountered mirror those seen in any child undergoing transplantation. Renal transplantation is regularly successful in infancy and should be considered an integral component of the therapy for any child with chronic renal failure.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02125797
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 21
    Electronic Resource
    Electronic Resource
    Sodium-taurine cotransport in reptilian renal brush-border membrane vesicles (1992)
    Springer
    Pflügers Archiv 421 (1992), S. 168-175 
    Details
    ISSN: 1432-2013
    Keywords: Taurine ; Kinetic ; Stoichiometry ; Amino acid transport ; β-Amino acid ; Membrane vesicle ; Kidney ; Sodium-coupled transport
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The coupled transport of Na+ with taurine into snake renal brush-border membrane vesicles (BBMV) was studied using 5-s uptake conditions. Taurine transport into snake renal BBMV involved two parallel processes, one saturable (Na+-dependent) and one (Na+-independent) that behaved like passive diffusion. Below 1 mM taurine concentration, the Na+-dependent system accounted for 60% of total taurine uptake. Over both low (0.001–0.80 mM) and high (0.8–5.0 mM) taurine concentration ranges, the Na+-dependent taurine uptake within each range showed Michaelis-Menten kinetics, suggesting the presence of two independent saturable Na+-dependent transport systems for taurine. The high-affinity, low-capacity system saturated above 100 μM with a K m of 71.4±45.7 μM and a maximum velocity (V max) of 21.9±3.77 pmol (mg protein)−1 (5 s)−1. The low-affinity, high-capacity system saturated above 1 mM, with a K m of 1.11±0.63 mM and a V max of 252±47 pmol (mg protein)−1 (5 s)−1. The stoichiometric relationship between external Na+ concentration and taurine uptake (at 10 μM) by the high-affinity BBMV transport system was examined by the activation method under short-circuited conditions. The 5-s rate of taurine transport was a sigmoid function of increasing extravesicular Na+ concentration. Kinetic analysis of the interaction of Na+ with the high-affinity taurine transport system suggested that 3 Na+ ions (3.2±0.7) may be involved with 1 taurine molecule in the transport event. The data suggest the presence of a highly efficient and high-affinity reabsorptive taurine transport system on the luminal membrane of the kidney of the garter snake, a species that can secrete taurine in vivo.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00374824
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 22
    Electronic Resource
    Electronic Resource
    Distribution of histamine in the rat kidney during pregnancy and development (1992)
    Springer
    Cell & tissue research 267 (1992), S. 233-239 
    Details
    ISSN: 1432-0878
    Keywords: Development, ontogenetic ; Kidney ; Glomerulus ; Distal convoluted tubule (DCT) ; Histamine ; Immunohistochemistry ; Hybridization, in situ ; Rat (Wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary An antiserum against conjugated histamine and two oligonucleotide probes that detect the mRNA encoding L-histidine decarboxylase (HDC) involved in histamine synthesis were used to study the appearance of histamine and its location in the kidneys of fetal, newborn and young postnatal rats and in the kidneys of pregnant rats. On embryonic days 16 and 18 (E16 and E18), some HA-immunoreactive (HA-ir) cells were found within the largest S-shaped bodies. Histamine was found to appear rapidly between the 18th and 20th embryonic days in the convoluted tubules of the kidneys. On postnatal day 0 (P0), the distal convoluted tubules and collecting ducts exhibited bright fluorescence, the intensity of which decreased quickly so that it was faint on day P4 and absent at later stages. In kidneys of pregnant rats HA-ir was found in the epithelium of both the Bowman's capsule, collecting ducts and in a few cells within the tubules. Nonuniform HA-ir was also detected within glomeruli. No evidence for the presence of L-histidine decarboxylase mRNA in kidneys of fetuses or pregnant rats was seen. It is concluded that distinct structures in the developing rat kidney contain histamine during a period around birth from day E20 to day P4. In the pregnant rat, the epithelium that is in direct contact with the urine flow is immunoreactive for histamine from day 16 to 20 of pregnancy. The results suggest that histamine is not synthesized locally in the kidneys but rather originates from other tissues.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00302960
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 23
    Electronic Resource
    Electronic Resource
    Total numbers of glomeruli and individual glomerular cell types in the normal rat kidney (1992)
    Springer
    Cell & tissue research 270 (1992), S. 37-45 
    Details
    ISSN: 1432-0878
    Keywords: Kidney ; Glomerulus ; Stereology ; Morphometry ; Disector ; Quantitative methods, structural ; Rat (Sprague Dawley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Alterations in numbers of glomeruli and glomerular cells occur in various renal disorders. Although values for these parameters have previously been reported for several species, the estimates have often been biased due to assumptions regarding glomerular and/or nuclear size and shape. Other studies have used tedious serial-section reconstruction methods. In the present study, unbiased stereological methods were used to estimate total numbers of glomeruli and individual glomerular cell types in normal rats. The kidneys of seven adult Sprague-Dawley rats were perfused with 4% paraformaldehyde and 1% glutaraldehyde in phosphate buffer and embedded in either glycolmethacrylate (for light microscopy, LM) or Epon/Araldite (for transmission electron microscopy, TEM). Total glomerular number was estimated using an LM physical disector/fractionator combination; the total number of cells per average glomerulus was estimated using an LM optical disector/ Cavalieri combination; and TEM physical disectors were used to count individual cell types. The normal rat kidney was found to contain 31764±3667 (mean±SD) glomeruli. An average glomerulus contained 674±129 cells, of which 181±53 were epithelial cells (podocytes), 248±53 were endothelial cells, and 245±45 were mesangial cells. An average renal corpuscle contained 117±27 parietal epithelial cells. Following sectioning and staining, less than 6.5 h was needed to obtain the above estimates for a single animal, with coefficients of variation (SD as a percent of the mean) ranging from 10% to 25%. The unbiased stereological methods used in the present study constitute an unbiased, precise and cost-efficient set of quantitative tools for assessing glomerular morphology in health and disease.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00381877
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 24
    Electronic Resource
    Electronic Resource
    Confocal microscopic and other observations on the distal end of the thick limb of the human loop of Henle (1992)
    Springer
    Cell & tissue research 267 (1992), S. 11-16 
    Details
    ISSN: 1432-0878
    Keywords: Kidney ; Distal tubule ; Tamm-Horsfall protein ; Cytokeratin ; Immunohistochemistry ; Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Various antibodies and lectins were used in a histological study of the human renal tubule, particularly of the distal end of the thick limb of the loop of Henle. The thick limb, identified by antibody to Tamm-Horsfall protein, ended abruptly, either at the macula densa or at a variable distance after it. At this point there was an abrupt change in cell size. Confocal microscopy and other techniques showed that this point marked an abrupt beginning of tubular staining by the cytokeratin antibody PKK 2 and the lectin UEA 1, with an abrupt end of staining by the lectin DBA. Distal from this point, there were gradual changes in staining of the tubule by various reagents including other antibodies to cytokeratins. These structural findings suggest that there is a fundamental change in the tubule at the end of the thick limb. The abrupt end to the thick limb in man resembles that seen in the rat and the rabbit.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00318686
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 25
    Electronic Resource
    Electronic Resource
    Immunohistochemical localization of transthyretin in glomerular peripolar cells of newborn sheep (1992)
    Springer
    Cell & tissue research 267 (1992), S. 193-197 
    Details
    ISSN: 1432-0878
    Keywords: Transthyretin ; Kidney ; Peripolar cells ; Sheep, newborn
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Purified transthyretin has been isolated from sheep serum. Antiserum raised against this protein has been used with an indirect immunoperoxidase histochemical technique to identify transthyretin in newborn lamb kidney tissue. Transthyretin was found in proximal tubule cells and in glomerular peripolar cells. Preabsorption studies using purified transthyretin protein indicate that the immunoreactivity of the antiserum is specific to transthyretin.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00318704
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 26
    Electronic Resource
    Electronic Resource
    Non-granulated peripolar cells exist in the rat glomerulus (1992)
    Springer
    Cell & tissue research 268 (1992), S. 567-570 
    Details
    ISSN: 1432-0878
    Keywords: Peripolar cell ; Glomerulus ; Kidney ; Cytoplasmic granules ; Scanning electron microscopy ; Rat (Sprague-Dawley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The peripolar cell is a unique cell type in the mammalian glomerulus. Peripolar cells are said to be identifiable during light microscopy by their cytoplasmic granules and by their position at the vascular pole; and during scanning electron microscopy by their distinctive surface morphology. We used both techniques to count peripolar cells in 6 normal rat kidneys. Scanning microscopy revealed that 55(±5)% of glomeruli contained at least one peripolar cell whereas light microscopy revealed granulated peripolar cells in only 4(±2)% of glomeruli. Vascular poles which contained peripolar cells previously identified by scanning were then examined by light and by transmission electron microscopy. Serial sections through these peripolar cells demonstrated the absence of cytoplasmic granules. Our observations suggest that the majority of peripolar cells in the rat contain no granules.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00319164
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 27
    Electronic Resource
    Electronic Resource
    The structure and biochemistry of the vacuolar H+ ATPase in proximal and distal urinary acidification (1992)
    Springer
    Journal of bioenergetics and biomembranes 24 (1992), S. 351-359 
    Details
    ISSN: 1573-6881
    Keywords: Kidney ; collecting tubule ; intercalated cells ; urinary acidification ; acid-base balance ; proton pump ; V-ATPase ; regulatory proteins
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Physics
    Notes: Abstract Vacuolar H+ ATPases participate in renal hydrogen ion secretion in both the proximal and distal nephron. These plasma membrane forms of the vacuolar H+ ATPase are regulated physiologically to maintain the acid-base balance of the organism. Proton transporting renal cells have requirements for constitutive acidification of intracellular compartments for normal endocytic and secretory functions. Recent experiments have begun to reveal how the kidney regulates these proton pumps independently. Vacuolar H+ ATPases are a family of structurally similar enzyme which differ in the composition of specific subunits. Cytosolic regulatory enzymes are present in renal cells which may affect vacuolar H+ ATPases in certain membrane compartments selectively. The vacuolar H+ ATPase in the plasma membrane of intercalated cells resides in a specialized proton-transporting apparatus that translocates the enzyme between an intracellular membrane pool and the plasma membrane in response to physiologic stimuli.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00762528
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 28
    Electronic Resource
    Electronic Resource
    Traumatische Ruptur eines Nierentransplantats in eine chronische Lymphozele (1992)
    Springer
    Langenbeck's archives of surgery 377 (1992), S. 222-225 
    Details
    ISSN: 1435-2451
    Keywords: Lymphocele ; Kidney ; Transplantation ; Rupture ; Trauma
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Lymphozelen sind eine seltene Komplikation nach Nierentransplantationen (in unserem Krankengut 2,2%) und treten typischerweise in den ersten 3–4 Monaten nach der Transplantation auf. Im späteren Verlauf sind sie eine Rarität. Die traumatische Ruptur eines Nierentransplantats ist in unserem Krankengut mit über 1200 Nierentransplantationen bisher einmalig. Es wird der Fall eines 28jährigen Marines geschildert, der 19 Jahre nach der Transplantation eine traumatische Nierentransplantatruptur erleidet. Durch das Trauma wird eine vorbestehende chronische Lymphozele klinisch manifest. Die Histologic der Lymphozelenwand zeigt Fett- und Bindegewebe mit ausgeprägter Fibrose. Das diagnostische und therapeutische Vorgehen wird beschrieben und mögliche Zusammenhänge den beiden seltenen Ereignisse diskutiert.
    Notes: Summary The lymphocele is a seldom complication after kidney transplantation (2.2% of our patients). This manifestation occurs typically 3–4 months after transplantation, as a late complication it's a rarity. The rupture of a kidney graft because of a trauma is unique in our clinical experience, which contains more than 1200 kidney transplantations. We report the case of a 28-year-old man who had 19 years after transplantation a traumatic rupture of the kidney graft. Because of the trauma a preexistent chronic lymphocele got clinically manifest. The histology of the lymphocele wall shows fatty and collagen tissue with a strong fibrosis. The diagnostic and therapeutic procedure is described. There are different possible relations between the rare problems: — the tight lymphocele carries over the force on the graft — the lymphocele has grown together with the graft at the lower pole and ruptures in this place — a little graft rupture makes a clinical manifest bleeding in the lymphocele because the deficiency of perirenal tissue.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00210277
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 29
    Electronic Resource
    Electronic Resource
    Cutaneous ion exchange, and renal and extrarenal partitioning of acid and ammonia excretion in the larval tiger salamander, Ambystoma tigrinum, following ingestion of ammonium salts (1992)
    Springer
    Journal of comparative physiology 162 (1992), S. 416-423 
    Details
    ISSN: 1432-136X
    Keywords: Acid-base balance ; Cutaneous ion exchange ; Kidney ; Ammonia ; Amphibian, Ambystoma tigrinum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The skin/gills and the kidneys of aquatic amphibians are potential sites of acid-base regulation. The roles of these organs in acid-base balance were examined in larval Ambystoma tigrinum following gastric infusion of ammonium salts. A single dose of 1.75 mEq NH4Cl·100 g-1 produced a mixed acidosis by 1 h after gavage. By 8 h after ingestion, pH and HCO 3 − had increased and PCO2 had decreased as the animals recovered. A prolonged acidosis was developed in a second group by gavage of an initial dose (1.5 mEq·100 g-1), followed by periodic maintenance doses (0.25 mEq·100 g-1) to prolong the disturbance for 8 h. The magnitude of the acidosis during this period was similar to that seen at 1 h after ingestion in the time-course study. A third group of larvae were given NaCl as a control for salt loading, which induced a small but significant respiratory acidosis. Unidirectional fluxes of Na+ and Cl- were examined during these serial ingestions. Salt loading inhibited the influx of the ingested ion. Na+ influx increased during the NH4Cl-induced acidosis. A fourth group of larvae were used to partition acid and ammonia excretion between the skin and the kidneys. These animals were given (NH4)2SO4 to allow re-examination of Cl- flux rates under non-Cl--loaded conditions. The ensuing acidosis had a reduced respiratory component and, therefore, pH did not decrease as much. Cl- influx rates did decrease significantly under these conditions. In both control and acidotic conditions, the majority of the acid efflux was as ammonia and the skin was the primary site of acid excretion. However, both the skin and the kidneys increased total acid excretion, although the efflux across the skin showed a much greater increase. This suggests a primary role for the skin in acid-base regulation in aquatic amphibians.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00258963
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 30
    Electronic Resource
    Electronic Resource
    Projection methods in flexible multibody dynamics. Part II: Dynamics and recursive projection methods (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 35 (1992), S. 1941-1966 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: In Part I of this paper the kinematic relationships between the absolute, elastic and joint accelerations are developed. In this paper, these kinematic equations are used with the generalized Newton-Euler equations and the relationship between the actual and generalized reaction forces to develop a recursive projection algorithm for the dynamic analysis of open-loop mechanical systems consisting of a set of interconnected rigid and deformable bodies. Optimal matrix permutation, partitioning and projection methods are used to eliminate the elastic accelerations while maintaining the inertia coupling between the rigid body motion and the elastic deformation. Recursive projection methods are then applied in order to project the inertia of the leaf bodies onto their parent bodies. This leads to an optimal symbolic factorization which recursively yields the absolute and joint accelerations, and the joint reaction forces. The method presented in this paper avoids the use of Newton-Raphson algorithms in the numerical solution of the constrained dynamic equations of open-loop kinematic chains since the joint accelerations are readily available from the solution of the resulting reduced system of equations. Furthermore, the method requires only the inversion or decomposition of relatively small matrices and the numerical integration of a minimum number of co-ordinates. Open-loop multibody robotic manipulator systems are used to compare the results and efficiency of the recursive methods with that of the augmented formulations that employ Newton-Raphson algorithms.
    Additional Material: 20 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620351003
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 31
    Electronic Resource
    Electronic Resource
    Coupling finite elements and magnetic networks in magnetostatics (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 35 (1992), S. 1991-2002 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: In this paper a new method for computing non-linear magnetostatic fields is introduced, which allows the simultaneous coupling of a finite element structure with a magnetic network. Combining the advantages of both methods while avoiding their drawbacks, this coupling yields both an accurate and time-efficient computation.The traditional method of the unknown mesh fluxes is applied for the solution of the magnetic network. The finite element solution, on the other hand, is based on a classical first-order interpolation of the unknown vector potential. The coupling is established by a proper organization of the unknowns on the boundary common to the finite element and network regions. In this way, a single system of non-linear equations is obtained.Moreover, it is shown that the coupled system of equations is equivalent to a single finite element system if generalized base functions are allowed. Consequently, various results from finite element theory may be applied. For instance, the matrix governing the iteratively linearized system of equations can directly be shown symmetrical and positive definite.Finally, the field inside a permanent magnet motor is calculated with the coupled method. Although the number of unknowns is dramatically reduced compared to a full FE calculation, the same level of accuracy is achieved. Hereby, the benefit of the coupled method is clearly proved.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620351005
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 32
    Electronic Resource
    Electronic Resource
    A consistent model for first-order moderate rotation plate theory (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 35 (1992), S. 2049-2066 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: The first-order shear deformation plate theory can be used in the small strain and moderate rotation non-linear elasticity by defining correctly the displacement vector form. In this paper, the problem of the consistency between the displacement vector form and the finite strain tensor approximation is analysed. Then, a new moderate rotation theory is proposed. The variational form of the governing equations is derived for the beam and the plate problems in a consistent way. Then, an iterative numerical procedure based on the finite element method and the secant striffness matrix is developed in order to solve the non-linear differential equation problem. Computations are made for one- and two-dimensional structures, in order to assess the performance of the von Kármán, finite elasticity, classical and the proposed moderate rotation theories.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620351008
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 33
    Electronic Resource
    Electronic Resource
    Conference diary (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 35 (1992), S. 2103-2104 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620351012
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 34
    Electronic Resource
    Electronic Resource
    Direct evaluation of singular boundary integrals in two-dimensional biharmonic analysis (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 35 (1992), S. 2067-2078 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: Development of techniques to provide rapid and accurate evaluation of the integrations required in boundary element method (BEM) formulations are receiving more attention in the literature. In this work, a series of direct expressions for surface integrals, required for a boundary element solution of the non-homogeneous biharmonic over a general two-dimensional curvilinear surface, are presented. The concept of an isoparametric representation, usually applied to the variation of the field variables and the geometry, is extended to the parametric mapping of the curvilinear geometry. The result renders the typically complicated Jacobian function into a series of polynomial expressions based on the shape function set and several discrete Jacobian values. An application of the isoparametric approximation of the Jacobian for a quadratic element representation is developed. Implementation of this approximation significantly improves the accuracy of the boundary integral solution by eliminating error associated with numerical quadrature. Overall computational efficiency is improved by reducing the time necessary to calculate individual surface integrals and evaluate field variables at internal points. A numerical solution of the boundary integral equations of phenomena governed by the biharmonic equation is presented and compared with an exact analysis.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620351009
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 35
    Electronic Resource
    Electronic Resource
    An infinite boundary element formulation for three-dimensional potential problems (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 35 (1992), S. 2079-2100 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: An infinite boundary element (IBE) is presented for the analysis of three-dimensional potential problems in an unbounded medium. The IBE formulations are done to allow their coupling with the finite element (FE) matrices for finite domains and to obtain the overall matrices without destroying the banded structure of the FE matrices. The infinite body is divided into a number of zones whose contributions are expressed in terms of the nodal quantities at FE nodes by employing suitable decay functions and performing mainly analytical integrations of the boundary element kernels. The continuity and compatibility conditions for the potential and the flux at the FE-IBE interface are developed. The relationships for the contributions of the IBE flux vectors to the FE load vectors are given. The final equations for the IBE are obtained in the usual FE stiffness-load vector form and are easily assembled with the FE matrices for the finite object. A series of numerical examples in heat transfer and electromagnetics were solved and compared with alternative solutions to demonstrate the validity of the present formulations.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620351010
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 36
    Electronic Resource
    Electronic Resource
    Creep deformation structural analysis using an efficient numerical algorithm (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 35 (1992), S. 1427-1442 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: This paper presents a fast numerical algorithm for the implementation of material models for creep into finite element codes. First, an overview of existing algorithms for transient and steady-state creep is given. Next, a new formulation is presented which reduces the constitutive integration to the solution of a scalar non-linear algebraic equation. A solution is shown to exist without the need for subincrementation. Details of the numerical algorithm are then discussed. The paper closes with several numerical examples which illustrate the speed, robustness and accuracy of the proposed procedure as implemented in the Lawrence Livermore National Laboratory finite element codes NIKE2D and NIKE3D.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620350704
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 37
    Electronic Resource
    Electronic Resource
    How to recognize the order of infinitesimal mechanisms: A numerical approach (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 35 (1992), S. 1351-1395 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: Structures presenting kinematical inderterminacy are usually called mechanisms. This paper is entirely concerned with assemblies which reveal themselves to be mechanisms at a null value of the load. Among them a first distinction is made between infinitesimal and finite ones, the former being characterized by one or several directions of lower (but not zero) stiffness, whereas the latter show at least one finite admissible displacement for which none of the bars undergoes any elongation. Moreover, there exists the possibility to make a further distinction among the infinitesimal mechanisms, according to which is the order of the stiffness along the direction considered above. The way of evaluating this order is to perform a local analysis of the strain energy of the assembly, once the displacement field is parametrized in terms of a suitable parameter. By means of a finite element technique, this analysis can be easily performed through the numerical approach presented in this report.
    Additional Material: 25 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620350702
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 38
    Electronic Resource
    Electronic Resource
    Solutions to shape and topology eigenvalue optimization problems using a homogenization method (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 35 (1992), S. 1487-1502 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: A solution strategy to find the shape and topology of structures that maximize a natural frequency is presented. The methodology is based on a homogenization method and the representation of the shape of the structure as a material property. The problem is formulated as a reinforcement problem in which a given structure is reinforced using a prescribed amount of material. Two dimensional, plane elasticity problems are considered. Examples are presented for illustration.
    Additional Material: 16 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620350707
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 39
    Electronic Resource
    Electronic Resource
    Announcements (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 35 (1992), S. 1541-1542 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620350710
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 40
    Electronic Resource
    Electronic Resource
    Masthead (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 35 (1992) 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620350901
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 41
    Electronic Resource
    Electronic Resource
    Masthead (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 33 (1992) 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620330101
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 42
    Electronic Resource
    Electronic Resource
    Numerical solution of integral equations with a logarithmic kernel by the method of arbitrary collocation points (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 33 (1992), S. 143-148 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: An integral equation whose kernel presents logarithmic singularity is numerically solved by the method of arbitrary collocation points (ACP). As a first step a Gaussian quadrature of order n (hence of polynomial accuracy 2n- 1) is employed for the numerical approximation of the integral. Until now the collocation, which follows, was performed on special points x̄k, determined as roots of appropriate transcedental functions, in order to retain the 2n - 1 degree of polynomial accuracy of the Gaussian quadrature. In this paper an appropriate interpolatory technique is proposed, so that xk may be arbitrary and yet the high (2n - 1) accuracy of the Gaussian quadrature is retained.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620330110
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 43
    Electronic Resource
    Electronic Resource
    Stabilized rapidly convergent 18-degrees-of-freedom flat shell triangular element (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 33 (1992), S. 149-162 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: A rank-sufficient flat triangular shell element with drilling degrees-of-freedom is described. A variational basis for this element has been provided by a three-field variational principle with relaxed interelement compatibility and traction continuity conditions. A generalized spurious mode control procedure has been developed in order to stabilize zero energy kinematical modes. Excellent performance has been found in an obstacle course and buckling problems.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620330111
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 44
    Electronic Resource
    Electronic Resource
    Some comments on: Benchmark problems and testing of a finite element code for solidification in investment castings (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 33 (1992), S. 213-215 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620330114
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 45
    Electronic Resource
    Electronic Resource
    Computational structural mechanics and optimal control - the simulation of substructural chain theory to linear quadratic optimal control problemsJoint project of the Natural Science Foundation of China and the Royal society. (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 33 (1992), S. 197-211 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: The theory of optimal control and the theory of a substructural chain in static structural analysis are mutually simulated issues. From the minimum potential energy variational principle of the substructural chain, the generalized variational principle with two kinds of variables is derived first. By comparing that generalized variational principle with the variational principle in LQ control theory, the simulation relation is established. Based on that relation, the potential energy and mixed energy formulation of the algebraic Riccati equations are derived, then iterative algorithms are proposed which give the upper and lower bounds to the solution matrix. By using the solutions of the positive and negative co-ordinate algebraic Riccati equations, the canonical transformation matrices for the eigenproblems of the substructural chain and LQ control are constructed respectively, which reduce the eigenproblem to half-size. The properties of the solutions are analysed, which establishes the basis for expansion solutions.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620330113
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 46
    Electronic Resource
    Electronic Resource
    Computer-aided analysis and design of electromagnetic devices, by S. Rantajeevan H. Hoole, Elsevier Science Publishing company, New York. 1989. ISBN 0-444-01327-x (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 33 (1992), S. 217-219 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620330116
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 47
    Electronic Resource
    Electronic Resource
    Reliability in computational mechanics, edited by J. T. Oden, Elsevier Science Publications, NY, 1990. No. of pages: 388. Price: $192.25. ISBN 0-444-88560-9 (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 33 (1992), S. 220-220 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620330117
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 48
    Electronic Resource
    Electronic Resource
    Conference diary (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 33 (1992), S. 221-222 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620330118
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 49
    Electronic Resource
    Electronic Resource
    Masthead (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 33 (1992) 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620330201
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 50
    Electronic Resource
    Electronic Resource
    Free vibration of axisymmetric and beam-like cylindrical shells, partially filled with liquid (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 33 (1992), S. 235-268 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: A theory is presented for the determination of the free vibration characteristics of anisotropic thin cylindrical shells, partially or completely filled with liquid, for two circumferential wave numbers, n = 0, axisymmetric and n = 1, beam-like. The method used was a combination of finite element analysis and classical shell theory. The shell was subdivided into cylindrical finite elements and the displacement functions were obtained using the shell equations. Expressions for the mass and stiffness matrices for a finite element and for the whole structure were obtained. A finite element was developed for the liquid in cases of potential flow. The natural frequencies of the shell, both empty and partially filled, were obtained and compared with existing experiments and other theories.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620330203
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 51
    Electronic Resource
    Electronic Resource
    Effective modelling of spatial buckling of beam assemblages, accounting for warping constraints and rotation-dependency of moments (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 33 (1992), S. 469-502 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: A simple, two-noded, finite element model for the three-dimensional buckling analysis of beam assemblages is developed. The underlying generalized-beam theory employed accounts for all coupled significant modes of deformations, including stretching, bending, shear and torsion, as well as warping. Its mixed formulation is of the two-field type, utilizing linear and constant interpolants for displacements and strain fields. Due considerations are given to the effect off inite rotations in space on the non-linear kinematic descriptions as well as the configuration-dependent behaviour of externally applied moment vectors of the conservative and non-conservative types. The performance of the model, and particularly the accuracy of its geometric and load-correction stiffnesses, is assessed in a fairly complete set of numerical simulations.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620330303
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 52
    Electronic Resource
    Electronic Resource
    Finite element calculation of energy release rate for 2-D rubbery material problems with non-conservative crack surface tractions (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 33 (1992), S. 907-927 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: The energy release rate G for 2-D rubbery material problems with non-conservative crack surface tractions is calculated by a modified version of virtual crack extension method with finite element solutions. The formulation is demonstrated to be ‘patch-independent’ and therefore a complicated finite element model around the crack tip is not required.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620330503
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 53
    Electronic Resource
    Electronic Resource
    A numerical technique for the analysis of cracks subjected to normal compressive stresses (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 33 (1992), S. 929-942 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: The purpose of the present paper is the development of a numerical method for the evaluation of the Stress Intensity Factor in mode II at the tips of closed cracks subjected to compressive normal stresses and monotonically increasing shear stresses. A hybrid Boundary Element Technique, originally developed for the analysis of open cracks, has been suitably modified. The Stress Intensity Factor is evaluated directly on the basis of the displacement discontinuities computed at the crack tip element, by taking into account the development of frictional resistance on the crack surfaces. A limited number (10-15) of displacement discontinuity elements is found to be sufficient for an accurate evaluation of the Stress Intensity Factor. Some basic aspects of the mechanical behaviour of closed cracks are also investigated on the basis of the proposed method.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620330504
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 54
    Electronic Resource
    Electronic Resource
    A thick-thin triangular plate element (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 33 (1992), S. 963-973 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: A simple and efficient triangular finite element is introduced for plate bending applications. The element is a three-node triangular one with three basic degrees of freedom per node and two internal rotation degrees of freedom, using selective reduced integration. Numerical examples indicate that, despite its simplicity, the element is not only competitively accurate, but also useful as a thick-thin triangular plate bending element. It is also pointed out that this element using selective reduced integration is in fact a mixed element.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620330506
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 55
    Electronic Resource
    Electronic Resource
    An integration scheme for Prandtl-Reuss elastoplastic constitutive equations (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 33 (1992), S. 943-961 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: We investigate the Generalized Midpoint Rule for the time integration of elastoplastic constitutive equations for pressure-independent yield criteria. The incremental equations are divided into one scalar hydrostatic pressure/dilation rate equation, and a stress deviator/strain rate deviator tensorial equation, the solution of which reduces to one single scalar equation in the plastic multiplier. The existence and uniqueness of an incremental solution is discussed. The pressure/deviator decomposition is the basis for reduced integration of the pressure term in the Principle of Virtual Work, in order to avoid locking and spurious pressure oscillations. It is also shown that an optimal choice of the parameter of the Midpoint Rule can be computed by reference to the analytical solution of the equations assuming no work hardening. A benchmark test shows that this choice allows increased time steps. This formulation is applied to two classical problems: bulging of a tube under internal pressure and tension test on a notched specimen, and a comparison with the analytical solution is performed. Finally, the hypothesis which sustains these formulations of elastoplasticity (constant strain rate during an increment) is discussed with reference to elastic unloading and residual stress computation.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620330505
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 56
    Electronic Resource
    Electronic Resource
    Delaunay's mesh of a convex polyhedron in dimension d. application to arbitrary polyhedra (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 33 (1992), S. 975-995 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: This paper presents a method for creating a Delaunay triangulation connected to a set of specified points. The theoretical aspect is recalled for an arbitrary dimension and the method is discussed in order to derive a practical approach, valid for dimensions 2 and 3, which is simple, robust and well adapted to computation. Convex polyhedral and arbitrary polyhedral situations are introduced.
    Additional Material: 17 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620330507
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 57
    Electronic Resource
    Electronic Resource
    Theoretical development and numerical verification of a geometrically non-linear, 3-D based finite element for composite materials (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 33 (1992), S. 1119-1138 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: A geometrically non-linear thin shell element made from classical laminated materials is developed from three dimensional continuum concepts that admits arbitrarily large displacements and rotations. The development shows how explicit integration through the thickness of the element can be accomplished without sacrificing significant accuracy of the element.Computations obtained via the present formulation are compared with four test problems for which numerical data are available. All computations were carried out using the Crisfield-Riks arc length continuation algorithm with a full Newton-Raphson iterative scheme. Excellent agreement is observed for each test problem.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620330603
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 58
    Electronic Resource
    Electronic Resource
    A new explicit variable time-integration self-starting methodology for computational structural dynamics (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 33 (1992), S. 1165-1180 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: A new explicit variable time-integration methodology and architecture which possesses self-starting attributes, eliminates the need to involve acceleration computations, and which has improved accuracy characteristics in comparison to the traditional central-difference-type formulations customarily advocated is described for applicability to computational structural dynamics. To sharpen the focus of the present study, an explicit variable time-integration architecture which is relatively simple, yet effective, is described. Unlike variable explicit time-integration formulations adopted in the past, the present self-starting variable time-integration architecture and implementation aspects facilitate a simplified representation and a straightforward and effective approach for combining finite element meshes requiring different time steps in a single analysis. Numerical test cases are provided which demonstrate the applicability of the proposed formulations.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620330605
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 59
    Electronic Resource
    Electronic Resource
    An optimal method for the solution of the constrained eigenvalue/response problem for large structures comprising rigidly-connected substructures (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 33 (1992), S. 1139-1163 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: Dynamic substructuring or modal synthesis is established as a powerful means by which the computational effort required to perform dynamic analyses of large structures comprising many degrees of freedom can be reduced. For the case where the substructures are rigidly connected a method of synthesis is proposed which gives very substantial improvements in efficiency over existing methods both in terms of the number of floating-point operations which must take place and the on-board computer memory required. The proposed method makes use of a stable co-ordinate transformation which reduces the mass matrix for the constrained composite-system to the identity matrix and makes the stiffness matrix banded. The bandwidth is exactly equal to twice the total number of constraints plus 1. This is usually very small in comparison with the total number of degrees of freedom in the constrained composite-system. The proposed method is ideal for combining a number of substructures into a single new substructure in an efficient way without necessarily disposing of any degrees of freedom. Approximate formulae are presented which give the ratios of the number of operations required for established methods compared with the number needed for the proposed method. These formulae determine when it is appropriate to use the method proposed here.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620330604
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 60
    Electronic Resource
    Electronic Resource
    Non-singular boundary integral representation of potential field gradients (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 33 (1992), S. 1181-1195 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: In this paper we derive the non-singular boundary integral representation of the field gradients for two-dimensional problems of classical potential field theory. Numerical implementation of this representation is developed too. The proposed method eliminates the most inaccurate influence coefficients which arise when singular integral representations are used and the internal point approaches the boundary. Since the integrands in this new method are finite at any internal point, accurate numerical results are achieved even in that portion of a solid which is very close to a discretized boundary. Two test problems are analysed in which the numerical results computed by strongly singular, weakly singular and non-singular integral representations are compared mutually and with exact solutions.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620330606
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 61
    Electronic Resource
    Electronic Resource
    Computing alternative optimal collapse mechanisms (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 33 (1992), S. 1197-1216 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: Optimal plastic designs for structural frames can be obtained via static or kinematic considerations, each leading to a mathematical model requiring solution by linear programming. In both cases a mechanism can be found which satisfies the Foulkes optimality condition. However, this mechanism generally has many degrees of freedom and is most unlikely to be the actual collapse mode of the frame. A simple algorithm based on the method of redundant forces is presented for the automatic generation of the alternative optimal collapse mechanisms, any of which may be the actual collapse mode.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620330607
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 62
    Electronic Resource
    Electronic Resource
    ALE finite element formulation for ring rolling analysis (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 33 (1992), S. 1217-1236 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: In this paper, a ring rolling process is analysed by the Arbitrary Lagrangian Eulerian (ALE) finite element method. Phenomena associated with the process, such as large deformations, elastoplastic material behaviour and the friction on the interface, are included in the analysis. Special modelling on driven, idle and guide rolls is given. Results which include the overall shape of the formed ring, the time histories of roll separating force and driving torque, the distribution of the normal pressure on the ring-roll interface as well as the distribution of effective stresses in the formed ring, are also presented.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620330608
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 63
    Electronic Resource
    Electronic Resource
    On the development of explicit robust schemes for implementation of a class of hyperelastic models in large-strain analysis of rubbers (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 33 (1992), S. 1237-1249 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: The issue of developing effective and robust schemes to implement a class of the Ogden-type hypereiastic constitutive models, for large-strain analysis of rubber-like materials, is addressed. To this end, explicit forms for the corresponding material tangent-stiffness tensors are developed, and these are valid for the entire deformation range; i.e. with both distinct as well as repeated principal-stretch values. Throughout the analysis the various implications of the underlying property of separability of the strain-energy functions are exploited, thus leading to compact final forms of the tensor expressions. In particular, this facilitated the treatment of the complex cases of uncoupled volumetric/deviatoric formulations for incompressible materials, which are becoming increasingly popular in recent years. The forms derived are also amenable for use with symbolic-manipulation packages for systematic code generation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620330609
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 64
    Electronic Resource
    Electronic Resource
    Tetrahedral elements for fluid flow (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 33 (1992), S. 1251-1267 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: Several old and new tetrahedral elements are tested and compared to some classical hexahedral elements for the solution of three-dimensional incompressible fluid flow problems. The proposed elements are created by adding velocity degrees of freedom to the basic trilinear velocity, constant pressure tetrahedron so as to satisfy the Brezzi condition. Numerical tests carried out for an artificial divergence-free flow problem and the lid-driven cubic cavity up to a Reynolds number of 400 are used to compare the proposed elements and assess their accuracy.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620330610
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 65
    Electronic Resource
    Electronic Resource
    The dual boundary element method: Effective implementation for crack problems (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 33 (1992), S. 1269-1287 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: The present paper is concerned with the effective numerical implementation of the two-dimensional dual boundary element method, for linear elastic crack problems. The dual equations of the method are the displacement and the traction boundary integral equations. When the displacement equation is applied on one of the crack surfaces and the traction equation on the other, general mixed-mode crack problems can be solved with a single-region formulation. Both crack surfaces are discretized with discontinuous quadratic boundary elements; this strategy not only automatically satisfies the necessary conditions for the existence of the finite-part integrals, which occur naturally, but also circumvents the problem of collocation at crack tips, crack kinks and crack-edge corners. Examples of geometries with edge, and embedded crack are analysed with the present method. Highly accurate results are obtained, when the stress intensity factor is evaluated with the J-integral technique. The accuracy and efficiency of the implementation described herein make this formulation ideal for the study of crack growth problems under mixed-mode conditions.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620330611
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 66
    Electronic Resource
    Electronic Resource
    A study of boundary layers in plates using Mindlin-Reissner and 3-D elements (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 33 (1992), S. 1305-1320 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: Finite elements based on Mindlin-Reissner theory and three-dimensional theory are used to study the distribution of shear forces and twisting moments in plates with various simple support conditions. Differences between the results obtained using these two theories are highlighted. A crude adaptive mesh refinement procedure is applied to improve the accuracy of the finite-element analysis.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620330613
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 67
    Electronic Resource
    Electronic Resource
    Addendum - J. C. Simo and K.K. Wong, unconditionally stable algorithms for rigid body dynamics that exactly preserve energy and momentum, Int. J. Numer. Methods eng., 31, 19-52 (1991) (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 33 (1992), S. 1321-1323 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620330614
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 68
    Electronic Resource
    Electronic Resource
    Letters to the editor (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 33 (1992), S. 1325-1325 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620330615
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 69
    Electronic Resource
    Electronic Resource
    Announcements (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 33 (1992), S. 1329-1329 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620330617
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 70
    Electronic Resource
    Electronic Resource
    Conference diary (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 33 (1992), S. 1327-1328 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620330616
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 71
    Electronic Resource
    Electronic Resource
    On development of a finite dynamic element and solution of associated eigenproblem by a block Lanczos procedure (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 33 (1992), S. 1611-1623 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: The paper first presents the details of the development of a new six-noded plane triangular finite dynamic element. A block Lanczos algorithm is developed next for the accurate and efficient solution of the quadratic matrix eigenvalue problem associated with the finite dynamic element formulation. The resulting computer program fully exploits matrix sparsity inherent in such a discretization and proves to be most efficient for the extraction of the usually required first few roots and vectors, including repeated ones. Most importantly, the present eigenproblem solution effort is shown to be comparable to that of the corresponding finite element analysis, thereby rendering the associated dynamic element method rather attractive owing to superior convergence characteristics of such elements, presented herein.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620330805
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 72
    Electronic Resource
    Electronic Resource
    A mixed finite element formulation for non-linear analysis of plane problems (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 33 (1992), S. 1721-1736 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: Based on the incremental non-linear theory of solid bodies and the Hellinger-Reissncr principle, a mixed updated Lagrangian formulation of the large displacement motion of solid bodies is derived, and an associated mixed finite element model is developed. The model contains the displacements and stresses as the nodal degrees of freedom. The model is used for the large deformation elasto-plastic analysis of plane problems. In solving non-linear problems, the Newton-Raphson method with arc-length control is adopted to trace the post-buckling response. The computational steps to calculate the elasto-plastic stress increments at Gauss points in the elasto-plastic analysis by the present mixed model are described in detail. Numerical results are presented and compared with those of the displacement model and existing solutions to show the accuracy of the present mixed model in the large deformation elasto-plastic analysis of plane problems.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620330811
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 73
    Electronic Resource
    Electronic Resource
    Analytical elements of time domain bem for two-dimensional scalar wave problems (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 33 (1992), S. 1737-1754 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: An accurate and efficient time domain BEM for 2-D scalar wave problems is presented. Emphasis is on developing analytical boundary elements (explicit solutions of the element matrices). The solutions are obtained under the condition of straight line elements and by bringing the problem to a simple and genral form of double convolution equation which is then solved by the Cagniard-De Hoop method. Six kinds of elements for any combination of the spatial interpolation functions of order 0, 1, 2 with the temporal interpolation functions of order 0, 1 are given in a compact form. It is pointed out that if the order of temporal interpolation function is higher than 1, or if the continuity of velocity or acceleration is required, the time-stepping technique will face difficulty. A method to solve this problem is also presented.Advantages of using the analytical elements instead of a numerical integral procedure are apparent. Problems with such things as singular integrals, accuracy and stability are solved. Methodology and solutions are demonstrated by a comparative study of two example problems. Numerical solutions reveal that the computation is efficient, accurate and stable.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620330812
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 74
    Electronic Resource
    Electronic Resource
    Conference diary (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 33 (1992), S. 1771-1773 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620330814
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 75
    Electronic Resource
    Electronic Resource
    Masthead (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 33 (1992) 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620330901
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 76
    Electronic Resource
    Electronic Resource
    Element by element a posteriori error estimation of the finite element analysis for three-dimensional elastic problems (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 33 (1992), S. 1755-1769 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: An a posteriori error estimation method for finite element solutions for three-dimensional elastic problems is presented based on the theory developed by the authors for two-dimensional problems.1 The error is estimated for the finite element solutions obtained using three-dimensional 8-node elements with a linear interpolation function in an arbitrary hexahedron. The method is successfully applied to three-dimensional elastic problems. In order to decrease computing time and memory use, the error is estimated element by element. The major difficulty in the element-wise error estimation technique is satisfying the self-equilibrium condition of applied forces, especially in three-dimensional problems. These forces are mainly due to traction discontinuity on the element boundaries. The difficulty is circumvented by employing an element-wise optimal procedure. It is also shown that a very accurate stress solution can be obtained by adding estimated error to the original finite element solutions.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620330813
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 77
    Electronic Resource
    Electronic Resource
    A numerical model for determining the motion of a bubble close to a fixed rigid structure in a fluid (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 33 (1992), S. 1813-1822 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: This paper is concerned with the problem of modelling the motion of a bubble close to a rigid structure in an infinite fluid. It is well known that the boundary integral method is a powerful technique for modelling the motion of a single bubble in a fluid. In this paper we shall present a modified boundary integral method for modelling the motion of a bubble close to a fixed finite rigid structure, and discuss a numerical scheme for solving the resulting integral equation for three-dimensional problems. Finally, we illustrate our method with some typical numerical results.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620330904
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 78
    Electronic Resource
    Electronic Resource
    Application of infinite elements to phase change situations on deforming meshes (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 33 (1992), S. 1861-1874 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: In recent years progress has been made in applying moving and deforming mesh systems to phase change problems. This allows the numerical attention where it is needed, near the migrating phase change zone. In spatially unbounded problems one hopes that numerically finite outer boundaries either escape significant activity or are automatically pushed further away as activity nears. Not infrequently this approach fails. Temperature activity often spreads more rapidly than phase change, thereby reaching far boundaries; stretching of the mesh by movement of far boundaries can challenge mesh control and cause ill-conditioning. In this paper the advantages of time dependent mesh adaption are enhanced by the joining of a new formulation for infinite elements to far boundaries. This is accomplished through a co-ordinate transformation within the framework of conventional 2-D quadratic, biquadratic, and linear-quadratic elements. Standard 2 by 2 Gauss-Legendre quadrature suffices throughout and normal Galerkin finite element features are undisturbed, including strict conservation of energy. The formulation is independent of global co-ordinates, entails no restrictions on the unknown function and should be applicable to other problem types. All test cases on quadrilateral and triangular grids show very significant improvements with infinite elements relative to comparable solution systems using strictly finite grids.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620330907
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 79
    Electronic Resource
    Electronic Resource
    Coupling of physical and modal components for analysis of moving non-linear dynamic systems on general beam structures (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 33 (1992), S. 1843-1859 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: A general, well-structured and efficient method is advanced for the solution of-a large class of dynamic interaction problems including a non-linear dynamic system running at a prescribed time-dependent speed on a linear track or guideway. The method uses an extended state-space vector approach in conjunction with a complex modal superposition. It allows for the analysis of structures containing both physical and modal components. The physical components studied here are vehicles modelled as linear or non-linear discrete mass-spring-damper systems. The modal component studied is a linear continuous model of a track structure containing beam elements which can be generally damped and which can be embedded in a three-parameter damped Winkler-type foundation. The complex modal parameters of the track structure are solved for. Algebraic equations are established which impose constraints on the transverse forces and accelerations at the interfaces between the moving dynamic systems and the track. An irregularity function modelling a given non-straight profile of the non-loaded track or a non-circular periphery of the wheels is also accounted for. Loss of contact and recovered contact between a vehicle and the track can be treated. The system of coupled first-order differential equations governing the motion of the vehicles and the track and the set of algebraic constraint equations are together compactly expressed in one unified matrix format. A time-variant initial-value problem is thereby formulated such that its solution can be found in a straightforward way by use of standard time-stepping methods implemented in existing subroutine libraries. Examples for verification and application of the proposed method are given. The present study should be of particular value in railway engineering.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620330906
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 80
    Electronic Resource
    Electronic Resource
    Arbitrary Lagrangian-Eulerian finite element analysis of large deformation in contacting bodies (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 33 (1992), S. 1891-1925 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: The primary aim of this research is to implement the arbitrary Lagrangian-Eulerian finite element description to model large deformation of interacting bodies. A pure Lagrangian description is often incapable of representing their contact with sufficient precision. In this work, the arbitrary Lagrangian-Eulerian (ALE) description has been extended to the surface nodes of interacting bodies to overcome these limitations. A penalty formulation has been implemented to account for the impenetrability constraint. The materials have been characterized as elastic-viscoplastic. Implicit integration schemes have been used at the global and constitutive levels for'improved stability.
    Additional Material: 30 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620330909
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 81
    Electronic Resource
    Electronic Resource
    A solid shell element for the shell structured eyeball with application to radial keratotomy (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 33 (1992), S. 1875-1890 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: In order to obtain the curvature changes of the exterior surface of a shell subjected to an internal pressure, it is necessary to evaluate the displacement derivatives up to the second order. To this end, a hexahedronal element is developed with three-dimensional elastic properties utilized. At a nodal point on the surface of the shell, the first-order derivatives of the three displacement components are used as degrees of freedom (d.o.f.) in addition to the components themselves. However, at a nodal point not on the surface, only the three displacement components are used. Therefore, an element with aii exterior surface has a total of 48 d.o.f. and other elements have 24 d.o.f.The stiffness matrix of the 8-node subparametric hexahedronal high-order element is derived from the strain energy consideration. The cubic shape functions in the surface co-ordinates and linear shape functions through the shell thickness are used. The second derivatives of displacement components are continuous at any point on the exterior surface of the element, although they may not be continuous across the nodal line of two adjacent elements.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620330908
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 82
    Electronic Resource
    Electronic Resource
    Optimum design of structures with both natural frequency and frequency response constraints (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 33 (1992), S. 1927-1940 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: An efficient method is developed to compute the sensitivities of eigenvalues, eigenvectors and frequency responses in a reduced approximate rnodel. The reanalyses of a modified structure for those dynamic responses are also derived in the approximate model. An optimization process utilizing the efficiently calculated sensitivities and reanalyses of the modified structure is formed. The difficulties of finding eigenvector sensitivities for repeated modes have also been addressed and averted in the approximate model. Two numerical examples show satisfactory outcomes by using this proposed approach.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620330910
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 83
    Electronic Resource
    Electronic Resource
    Large displacement analysis of thin-walled beams with generic open section (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 33 (1992), S. 2109-2127 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: A finite element formulation for geometric non-linear analysis of elastic straight thin-walled beams is presented. The updated Lagrangian procedure is used for a stiffness matrix derivation-to analyse large displacements or buckling behaviour of space frames. The stiffness matrix is developed for a generic cross-section and is equally efficient for symmetric, monosymmetric or asymmetric open sections. Some non-linear strain terms usually neglected in the literature have been considered, resulting in a formulation which also includes the initial bimoment and torsion effect for all cross-sections analysed. The proposed method has been implemented and the results of sample problems are presented.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620331008
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 84
    Electronic Resource
    Electronic Resource
    Least squares element method for boundary eigenvalue problems (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 33 (1992), S. 2129-2143 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: Linear and non-linear boundary eigenvalue problems are discretized by a new finite element like method. The reason for the new construction principle is the non-linear dependence of the dynamic stiffness element matrix on an eigenparameter. The dynamic stiffness element matrix is evaluated for a fixed number of parameters and is then elementwise replaced by a polynomial in the eigenparameter by solving least squares problems. A fast solver is introduced for the resulting non-linear matrix eigenvalue problem. It consists of a combination of bisection method and inverse iteration. The superiority of the newconstructionprinciple in comparison with the finite or dynamic element method is demonstrated finally for some numerical examples.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620331009
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 85
    Electronic Resource
    Electronic Resource
    Conference diary (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 33 (1992), S. 2201-2203 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620331013
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 86
    Electronic Resource
    Electronic Resource
    On geometric invariance of tet4rx (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 33 (1992), S. 2199-2199 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620331012
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 87
    Electronic Resource
    Electronic Resource
    Stress oscillations and spurious load mechanisms in variationally inconsistent assumed strain formulations (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 33 (1992), S. 2181-2197 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: Assumed field-consistent strain formulations of the displacement finite element procedure can lead to poor convergence and spurious stress oscillations if the assumed strain fields are not variationally correct, i.e. they do not satisfy an important orthogonality condition emerging from the equivalence sought between assumed strain displacement procedures and mixed procedures based on the Hellinger-Reissner theorem. Failure to ensure variational correctness introduces errors which can be equated to the presence of spurious loading mechanisms that cause stress oscillations. In this paper, we use the Timoshenko beam element to demonstrate that field-consistency and variational' consistency are two complementary but mutually exclusive principles - one does not imply the other and that both are necessary to successfully implement a displacement type finite element for constrained media.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620331011
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 88
    Electronic Resource
    Electronic Resource
    Masthead (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 34 (1992) 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620340101
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 89
    Electronic Resource
    Electronic Resource
    Preface (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 34 (1992), S. 1-1 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620340102
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 90
    Electronic Resource
    Electronic Resource
    A structural mapping technique for geometric parametrization in the optimization of magnetic devices (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 33 (1992), S. 2145-2179 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: The continuity and differentiability of object functions is a basic prerequisite for the application of gradient methods in optimization. However, for parameters defining the shape of an electromagnetic device, the finite element discretization in the field analysis introduces discontinuities into the object function which slow down the convergence rate. Additionally, depending on the geometric parametrizaiion employed, the optimization frequently yields shape contours that are impracticable for manufacturing purposes. This paper investigates the problems inherent in geometric parametrization and shows that the discontinuities in the object function are caused by changes in mesh topology as the geometric parameters vary; these changes inevitably follow from the use of free meshing algorithms. As a solution to these shortcomings a structural mapping technique is outlined that maps surface displacements onto the parameters of the finite element mesh and obtains the parameter dependent geometric variations without a change in mesh topology. This resulting geometric parametrization yields continuous object functions without artificial local minima and results in smooth surface contours of the optimized device. Using this new parametrization technique, design sensitivity analysis, is shown to be a reliable and essential part in the efficient application of gradient methods for shape optimization.
    Additional Material: 16 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620331010
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 91
    Electronic Resource
    Electronic Resource
    NOte from local organising committee (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 34 (1992), S. 3-3 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620340103
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 92
    Electronic Resource
    Electronic Resource
    Non-linear analysis of sandwich shells (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 34 (1992), S. 61-71 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620340106
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 93
    Electronic Resource
    Electronic Resource
    Shell theory versus degeneration - a comparison in large rotation finite element analysis (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 34 (1992), S. 39-59 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: The first part of this study addresses the controversy ‘degenerated solid approach’ versus ‘shell theory’. It is shown that both formulations differ only in the kind of discretization if they are based on the same mechanical assumptions. In particular for degenerated shell elements different versions of explicit integration across the thickness are discussed. Among these are the approximation ‘Jacobian across the thickness is constant’, proven to be too restrictive, and the series expansion of the inverse Jacobian which turns out to be unnecessary although it leads to equations of the same order as those of a ‘best first approximation’ of a shell theory.The second part deals with the description of large rotations. It is demonstrated for problems formulated in three components of a rotation vector that a straightforward derivation results in a symmetric tangent stiffness matrix. However, a modified version is also added leading to an unsymmetric matrix already discussed in the literature. For shell problems with only two rotational variables both formulations coincide.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620340105
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 94
    Electronic Resource
    Electronic Resource
    An exact finite rotation shell theory, its mixed variational formulation and its finite element implementation (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 34 (1992), S. 73-115 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: A non-linear shell theory, including transverse shear strains, with exact description of the kinematical fields is developed. The strain measures are derived via the polar decomposition theorem allowing for an explicit use of a three parametric rotation tensor. Thus in-plane rotations, also called drilling degrees of freedom, are included in a natural way. Various alternatives of the theory are derived. For a special version of the theory, with altogether six kinematical fields, different mixed variational principles are given. A hybrid finite element formulation, which does not exhibit locking phenomena, is developed. Numerical examples of shell deformation at finite rotations, with excellent element performance, are presented. Comparison with results reported in the literature demonstrates the features of the theory as well as the proposed finite element formulation.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620340107
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 95
    Electronic Resource
    Electronic Resource
    Computational mechanics today (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 34 (1992), S. 9-33 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: Computational Mechanics or Computational Applied Science is today the base on which most of the achievements of engineering and physics are built. Its concern is the solution of complex mathematical theories in numerical terms, without which the translation of these into practical artifacts would be impossible. Indeed, by providing such quantitative measures it enhances the understanding of the physical phenomena and stimulates further development of theory and physical experiment.Most of the theory underlying physical phenomena is cast in terms of, often involved, differential equations for which closed forms of solution are seldom possible. Numerical approximation or discretization processes are necessary for quantitative solution. Here the first steps were taken at the start of this century by the pioneering work of Richardson introducing finite difference approximations. The invention of relaxation methods by Southwell during the Second World War allowed many practical solutions to be achieved. However, it was the advent of the electronic digital computer that marked the turning point in Computational Mechanics. The dramatic escalation of the power of these machines, which still continues today, allowed the development of the field of Computational Mechanics as we know it.It is through this computer power that such methods of approximations as finite elements, finite differences, boundary solutions and spectral processes became a practical reality, though each was anticipated in the pre computer area. It is not surprising therefore, that the mathematical foundations and the full development of such methods have been accomplished only relatively recently.Today we see the field of activity subdivided between those specializing in the development of the various computational approximation processes and those seeking optimal numerical solutions for their particular field of application. It is the objective of this Congress and indeed of the International Association of Computational Mechanics to provide a forum at which an interdisciplinary exchange of information can take place between the various sections and disciplines of the whole field. Indeed, this is the way progress can best be achieved. Recent history indicates that substantial advances are as frequently made due to a method seeking a new application as through a problem requiring a solution.In recent history we have seen on occasion a liaison of a particular computational approximation method to a field of application occurring through historical accident. Here the intimate association of the finite method and the field of SOLID MECHANICS (CSM or Computational Solid Mechanics) and that of the finite differences with FLUID DYNAMICS (CDF or Computational Fluid Dynamics) can be observed as classical examples. Today the advent of new application fields and a better understanding of the approximation theory are helping to break down the barriers and ensure a more rational matching of objectives and methods. We shall illustrate the lecture with examples of such recent progress and state some possibilities as yet unexplored. Indeed, we are sure that the Congress will achieve in much more detail the same aims.This presentation stresses the essential unity of the subject and discusses some areas where progress and research are currently active. Two of such, adaptive error controlled analysis and treatment of hyperbolic (fluid) problems, are singled out due to their wide applications.
    Additional Material: 15 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620340104
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 96
    Electronic Resource
    Electronic Resource
    Finite-rotation shell elements for the analysis of finite-rotation shell problems (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 34 (1992), S. 165-169 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: For the analysis of shell structures with finite displacements and rotations displacement-based and mixed finite-rotation shell elements are developed starting from consistent tensorial shell theories. The constraints for the description of the deformed normal vector have been considered at the element level as subsidiary conditions so that finite rotations in arbitrary strongly nonlinear situations can be considered without any difficulty. The efficiency of the finite-rotation elements is demonstrated by numerical examples.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620340109
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 97
    Electronic Resource
    Electronic Resource
    On a stress resultant geometrically exact shell model. Part VI: Conserving algorithms for non-linear dynamicsInvited lecture, presented at the World Congress of Computational Mechanics, Stuttgart, Germany, 1990 (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 34 (1992), S. 117-164 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: In Parts I to V of the present work, the formulation and finite element implementation of a non-linear stress resultant shell model are considered in detail. This paper is concerned with the extension of these results to incorporate completely general non-linear dynamic response. Of special interest here is the dynamics of very flexible shells undergoing large overall motion which conserves the total linear and angular momentum and, for the Hamiltonian case, the total energy. A main goal of this paper is the design of non-linear time-stepping algorithms, and the construction of finite element interpolations, which preserve exactly these fundamental constants of motion. It is shown that only a very special class of algorithms, namely a formulation of the mid-point rule in conservation form, exactly preserves the total linear and angular momentum. For the Hamiltonian case, a somewhat surprising result is proved: regardless of the degree of non-linearity in the stored-energy function, a generalized mid-point rule algorithm always exists which exactly conserves energy The conservation properties of a time-stepping algorithm need not, and in general will not, be preserved by the spatial discretization. Precise conditions which ensure preservation of these conservation properties are derived. A number of numerical simulations are presented which illustrate the exact conservation properties of the proposed methodology.
    Additional Material: 22 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620340108
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 98
    Electronic Resource
    Electronic Resource
    A universal method for including shear deformation in thin plate elements (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 34 (1992), S. 171-177 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: A universal method which can be used to generalize thin plate elements to thick ones without adding any extra degree of freedom (DOF) is presented in this paper. To illustrate this method, a rectangular moderately thick plate element with 12 DOF is constructed on the basis of the well known thin plate ACM element. The element can be used in the analysis of both thin and thick plates. Shear locking is avoided.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620340110
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 99
    Electronic Resource
    Electronic Resource
    A simplified analysis of plate structures using Trefftz-functions (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 34 (1992), S. 179-195 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: This paper presents a method for a quick evaluation of stresses and displacements in a plate structure for elastostatic problems. First, an approximation is built from the mathematical structure of the solutions for starshaped domains, which is representative of long wavelength effects. Second, a variational formulation consistent with this approximation is proposed. Finally, two alternative procedures for coupling adjacent domains are demonstrated.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620340111
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 100
    Electronic Resource
    Electronic Resource
    Signorini problem with Coulomb's law of friction. Shape optimization in contact problems (1992)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 34 (1992), S. 223-231 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620340114
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...