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  • 11
    Electronic Resource
    Electronic Resource
    EFFECT OF RE-COLD WORKING ON FATIGUE LIFE ENHANCEMENT OF A FASTENER HOLE (1995)
    Oxford, UK : Blackwell Publishing Ltd
    Fatigue & fracture of engineering materials & structures 18 (1995), S. 0 
    Details
    ISSN: 1460-2695
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The present study aims to assess the additional fatigue life enhancement obtained by coldworking a previously cold expanded plate hole. Two different methods of performing the second coldworking were considered, i.e. moving the mandrel in the same direction as for the first coldworking or moving it in the opposite direction. A three dimensional finite element analysis for establishing the residual stress field induced by two successive coldworkings (5.58% then 4.8%) was carried out. Al 7475-T7351 specimens with a central hole were cold expanded at 5.58%, subjected to cyclic loading at constant amplitude for a predetermined life fraction (on the basis of 5.58% cold expanded hole fatigue life) and then re-coldworked at 4.8%. After this rework, the specimens were again subjected to the same fatigue loading conditions until failure. During cycling, the fatigue crack extension was monitored using a video-camera in order to determine the coldworking effect on both the initiation period and the propagation life.The fatigue test results have shown that a second coldworking may enhance the fatigue life of an already coldworked hole. For a given cyclic loading level, the beneficial effect depends upon the applied life fraction before reworking. The direction of the mandrel movement during the second coldworking has no noticeable influence on the additional fatigue life improvement. These experimental results have been analyzed with reference to the calculated residual stress field.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1460-2695.1995.tb00902.x
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  • 12
    Electronic Resource
    Electronic Resource
    Flextensional Barium Strontium Titanate Actuators (2003)
    Westerville, Ohio : American Ceramics Society
    Journal of the American Ceramic Society 86 (2003), S. 0 
    Details
    ISSN: 1551-2916
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: This paper describes the performance of the cymbal flextensional transducer using Dy-doped barium strontium titanate (BST) as the driver material. BST was first characterized for its dielectric and loss behavior as a function of temperature and electrical bias field. With no electrical bias, the transition temperature was measured to be near 20°C and have a dielectric constant 〉20 000. The strain of a BST disk was then measured and compared with other ceramics. At room temperature the strain and average effective piezoelectric d33 of this non-lead composition was slightly larger than Navy type I lead zirconate titanate (PZT-4) ceramic. The strain/field behavior was also measured as a function of temperature. Cymbal capped BST ceramic was found to have an amplified displacement of 28×, also very similar to type I ceramic. The stiffness of BST was found to be tunable by dc voltage and 2 to 3 times larger than that of PZT. This material has promise for applications in actuators and transducers with large generative force.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1151-2916.2003.tb03400.x
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  • 13
    Electronic Resource
    Electronic Resource
    Kremen proteins are Dickkopf receptors that regulate Wnt/β-catenin signalling (2002)
    [s.l.] : Macmillian Magazines Ltd.
    Nature 417 (2002), S. 664-667 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] The Wnt family of secreted glycoproteins mediate cell–cell interactions during cell growth and differentiation in both embryos and adults. Canonical Wnt signalling by way of the β-catenin pathway is transduced by two receptor families. Frizzled proteins and ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/nature756
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  • 14
    Electronic Resource
    Electronic Resource
    Role of Fine-needle Aspiration Biopsy and Frozen Section Examination in Determining the Extent of Thyroidectomy (1998)
    Springer
    World journal of surgery 22 (1998), S. 575-580 
    Details
    ISSN: 1432-2323
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract. Traditionally the extent of thyroidectomy in patients with nodular thyroid disease has been based on peroperative frozen section examination (FS). Fine-needle aspiration biopsy (FNAB) and FS were evaluated with regard to the reliability to determine whether an operation for cancer is necessary. Both methods were performed in 240 patients operated for nodular thyroid disease and compared with the final histology on paraffin sections. Altogether 72 (30%) patients were found to have a malignant lesion on final histology. Only a malignant FNAB diagnosis and a malignant FS diagnosis were considered positive results for determining the extent of thyroidectomy. The test characteristics were equal: the sensitivity of FNAB and FS was 67%, the specificity 99%, and the accuracy 89%. The positive predictive value was 96% for FNAB and 98% for FS; the negative predictive values were 88% and 87%, respectively. Further analysis of the results indicates that FS is not necessary for patients with a malignant FNAB result. These patients should undergo a therapeutic operation for malignancy. When the FNAB result is uncertain, patients should undergo diagnostic surgery, and definitive surgery should be based on the final histology. Routine use of FS can be omitted.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002689900437
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  • 15
    Electronic Resource
    Electronic Resource
    Classical Behavior of the Dirac Bispinor (2000)
    Springer
    Foundations of physics 30 (2000), S. 35-57 
    Details
    ISSN: 1572-9516
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract It is usually supposed that the Dirac and radiation equations predict that the phase of a fermion will rotate through half the angle through which the fermion is rotated, which means, via the measured dynamical and geometrical phase factors, that the fermion must have a half-integral spin. We demonstrate that this is not the case and that the identical relativistic quantum mechanics can also be derived with the phase of the fermion rotating through the same angle as does the fermion itself. Under spatial rotation and Lorentz transformation the bispinor transforms as a four-vector like the potential and Dirac current. Previous attempts to provide this form of transformational behavior have foundered because a satisfactory current could not be derived.(14)
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1003686924816
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  • 16
    Electronic Resource
    Electronic Resource
    Chymotrypsin mRNA expression in digestive gland amoebocytes: cell specification occurs prior to metamorphosis and gut morphogenesis in the gastropod, Haliotis rufescens (1995)
    Springer
    Development genes and evolution 205 (1995), S. 97-101 
    Details
    ISSN: 1432-041X
    Keywords: Chymotrypsin ; Larva ; Metamorphosis Mollusc ; In situ hybridization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In the non-feeding larva of the marine gastropod, Haliotis rufescens, gut morphogenesis is initiated at metamorphosis. Intestine-specific chymotrypsin gene expression begins in amoebocytes located in the dorsoposterior region of the undifferentiated digestive gland prior to metamorphosis, 5 d post-fertilization. Transcript accumulates steadily in these cells over the next 6 d while the amoebocytes migrate slowly dorsally. Induction of metamorphosis dramatically accelerates the rates of chymotrypsin mRNA accumulation and amoebocyte migration, and is required for homing of the amoebocytes to the hindgut region. Induction of chymotrypsin gene expression occurs only in larvae that had developed competence to recognize an exogenous morphogenetic cue and initiate metamorphosis, with a more pronounced increase in chymotrypsin mRNA accumulation in occurring older larvae. Chymotrypsin mRNA accumulation patterns suggest that hindgut cell specification occurs prior to metamorphosis, but that completion of the morphogenetic program requires signaling events associated with metamorphosis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00188848
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  • 17
    Electronic Resource
    Electronic Resource
    Transient expression of a novel serine protease in the ectoderm of the ascidian Herdmania momus during development (1997)
    Springer
    Development genes and evolution 206 (1997), S. 455-463 
    Details
    ISSN: 1432-041X
    Keywords: Key words Ascidian ; Serine protease ; Differential display ; Gene expression ; In situ hybridization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  We have studied gene expression during ascidian embryonic development using the technique of differential display and isolated partial cDNA sequences of 12 genes. Developmental regulation of these genes has been confirmed by northern hybridization analysis. Further cDNA cloning and sequence analysis of an mRNA that is present during gastrulation, neurulation and tailbud formation reveals that it encodes a novel serine protease containing a single kringle motif and catalytic domain. The spatial expression of this gene, designated Hmserp1, is restricted to precursor cells of the epidermis. The structure and expression of Hmserp1 is discussed in relation to possible functions during development.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004270050075
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  • 18
    Electronic Resource
    Electronic Resource
    Setting of Gradient Material Properties and Quality Control of High Tension 3D-Weld Joints (2007)
    s.l. ; Stafa-Zurich, Switzerland
    Advanced materials research Vol. 22 (Aug. 2007), p. 113-125 
    Details
    ISSN: 1662-8985
    Source: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Modern metallic materials used in high loading structures are increasingly being placedunder stringent standards with regard to the mechanical strength and deformation properties of theirindividual parts as well as with regard to the loading capacity of their junctions. In order todetermine the strain profile of the individual structural components, the mentioned topics will betaken from the SFB 675 “High tensile, locally manipulated structural components and structures”from the subproject C4 “Setting of gradient material properties and qualification of high-tension3D-NVEB weld joints”. To this end, the strengthened individual structural components will beheated with an electron beam at defined locations. This is done in order to observe the load relatedlocal micro-structure changes and consequently the targeted, structured local changes in the strengthand deformation properties of the material. A delay in the crack growth will also be sought after.Additionally, components with specifically designed tensile strength will be welded to high qualitystructures. At this the young but efficient non vacuum electron beam welding method will bepreferably developed, qualified and used because of its good welding properties regarding to animproved beam positioning, process control and weld joint defect detection
    Type of Medium: Electronic Resource
    URL: http://www.tib-hannover.de/fulltexts/2011/0528/01/39/transtech_doi~10.4028%252Fwww.scientific.net%252FAMR.22.113.pdf
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  • 19
    Electronic Resource
    Electronic Resource
    Acute respiratory failure caused by secondary alveolar proteinosis in a patient with acute myeloid leukemia: a case report (1998)
    Springer
    Intensive care medicine 24 (1998), S. 265-267 
    Details
    ISSN: 1432-1238
    Keywords: Key words Pulmonary alveolar proteinosis ; Neutropenia ; Acute myeloid leukemia ; Acute respiratory failure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Pulmonary alveolar proteinosis (PAP) is a rare cause of chronic respiratory failure due to progressive alveolar accumulation of a periodic acid-schiff (PAS) positive proteinaceous material. In some cases, the rapid accumulation of intra-alveolar material leads to acute respiratory failure (ARF). We report the causative role of secondary PAP in the case of a 26-year-old man with acute myeloid leukemia who developed fever, increased serum lactate deshydrogenase level and ARF, and required mechanical ventilation. The diagnosis of PAP was established by the examination of material obtained by bronchoalveolar lavage (BAL). Respiratory improvement occurred several days after the patient had recovered from neutropenia. This report underlines the importance of the early diagnosis of PAP as a potential cause of ARF in leukemic patients. Adequate stain on BAL fluid provides the diagnosis and avoids repeated invasive procedures and inappropriate treatments.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001340050563
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  • 20
    Electronic Resource
    Electronic Resource
    Lhermitte-Duclos disease associated with syringomyelia (1996)
    Springer
    Neuroradiology 38 (1996), S. 529-531 
    Details
    ISSN: 1432-1920
    Keywords: Key words Lhermitte-Duclos disease ; Dysplastic gangliocytoma ; Magnetic resonance imaging ; Syringomyelia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A 23-year-old man presented with a 2-week history of intracranial hypertension. CT showed a large, nonenhancing cerebellar mass with surrounding calcification and displacement of the fourth ventricle. MRI revealed a septate lesion, with low signal on T1-weighted and high signal on T2-weighted images. The cerebellar tonsils were displaced below the foramen magnum and there was associated syringomyelia. The MRI features were characteristic of Lhermitte-Duclos (LD) disease (dysplastic gangliocytoma) and the diagnosis was confirmed following surgery. In this case, we emphasise the usefulness of MRI in the diagnosis of LD disease and consider the possible pathogenesis of the associated syringomyelia.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00626089
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