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  • Chemistry  (15)
  • Arteries  (2)
  • flooding  (2)
  • 34.50.Gb  (1)
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Calcified tissue international 3 (1969), S. 266-273 
    ISSN: 1432-0827
    Keywords: Calcification ; Arteries ; Membranes ; Elastic tissue
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé Avec la modification d'une méthode de von Kossa nous avons macroscopiquement representé les dessins de calcification de la membrane élastique intérieure, ainsi que les grosses artères du bassin, des artères des extrémités inferieures, des artères du bras, de la rate et des reins. Dans les artères du type élastique, dans les A.a. ilicae communes et internae, se présentaient les dégénérations calcaires de la membrane élastique intérieure sous forme d'incrustations noires arrondies ou polygonales qui ont été formes en groupes. Elles étaient toujours présentes chez des enfants agés de plus de trois mois et chez des aux adultes. Dans les artères musculaires, se montraient les parties calcifiées de la membrane élastique intérieure en forme de «bandes de calcaire» noires et groupes en paires le long des bordures des fissures de la membrane. Dans le cas où existait une calcinose forcée, on pouvait montrer avec cette méthode tout le système de fissures de la mambrane élastique intérieure. Chez tous les morts âgés de 10 à 20 ans, nous avons trouvé des bandes de calcaire dans les artères musculaires des extrémités inferieures. Ces bandes de calcaire ont été constatées aussi dans des personnes plus âgées. Au point de la fusion des bandes de calcaire et des incrustations calcaire polygonales des dépôts calcaires en forme de feuille («feuilles de calcaire») se forment dans la membrane elastique. Les bandes de calcaire et les feuilles de calcaire représentent des points de cristallisation pour des dépôts calcaire granuleux. Ils se forment dans la plupart des cas sur le la côté externe tourné vers la media.
    Abstract: Zusammenfassung Mit einer modifizierten von Kossa-Methode wurden die Verkalkungsmuster der inneren elastischen Membran der großen Beckenarterien, der Arterien der unteren Extremität, der Oberarm-, Milz-und Nierenarterien makroskopisch dargestellt. In den Arterien vom elastischen Typ, i.e. in den Aa. ilicae communes et internae, erschienen die Verkalkungen der inneren elastischen Membran als schwarze rundliche oder polygonale Inkrustationen, die zu Gruppen angeordnet waren. Sie wurden häufig bereits bei Neugeborenen festgestellt. Bei Kindern, die älter waren als 3 Monate und bei Erwachsenen lagen sie stets vor. — In den muskulären Arterien traten die verkalkten Anteile der inneren elastischen Membran makroskopisch als schwarze paarweise angeordnete „Kalkbänder” entlang den Rändern vorgebildeter Membranspalten auf. Bei ausgeprägter Calcinose konnte mit der angewandten Methode das gesamte Spaltensystem der inneren elastischen Membran dargestellt werden. Kalkbänder wurden in den muskulären Arterien der unteren Extremität bei allen 10–20 Jahre alten Verstorbenen vorgefunden und waren auch in den nachfolgenden Altersstufen stets vorhanden. Beim Zusammenfluß von Kalkbändern und polygonalen Kalkinkrustationen entstehen in der inneren elastischen Membran folienartige Kalkablagerungen („Kalkfolien”). Die Kalkbänder und Kalkfolien stellen Kristallisationspunkte für körnige Kalkablagerungen dar, die zumeist an ihrer äußeren, der Media zugekehrten Seite entstehen.
    Notes: Abstract Calcification patterns of the internal elastic membrane of the main pelvic arteries, lower limb arteries, brachial, splenic and renal arteries were demonstrated grossly by a modified von Kossa technique. In the elastic segment in the common and internal iliac arteries, the membrane calcification appeared as groups of roundish or polygonal incrustations. They were found frequently in newborns, and were always present in infants of more than three months, as well as in adults. In the muscular arteries, the calcified parts of the internal elastic membrane appeared grossly as pairs of bands (“calcific bands”) along the edges of the pre-existing gaps in this membrane. When calcification was pronounced, the whole pattern of the membrane gaps could be demonstrated by the method used in this study. Calcific bands were found in the muscular arteries of the lower limbs in all 10–20 year-old subjects, and were always present in the older age groups. The confluence of calcific bands or polygonal membrane incrustations found in the iliac arteries lead to sheet-like membrane calcification. The calcific bands and sheets represent crystallizing points for grain-like calcific deposits, which appear later on the medial surface.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1573-5036
    Keywords: aeration ; flooding ; Gossypium hirsutum L. ; root zone ; soil oxygen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Surface-irrigated cotton (Gossypium hirsutum L.) grown on slowly draining clay soil is subjected to short-term periods of waterlogging at each irrigation which generally results in reduced productivity. The sequence of above- and below-ground plant responses to transient waterlogging and the role of N availability in modifying the immediate responses were studied. Lysimeters of Marah clay loam (a Natrustalf) were instrumented to monitor soil and plant responses to a 7-day waterlogging event beginning 67 days after sowing. Cotton (‘Deltapine 61’) plants (8 per lysimeter) were grown with two levels of added N (300 kg ha−1 and 30 kg ha−1) and two irrigation treatments (flooded and control). Measured soil-O2 levels decreased rapidly upon surface flooding because water displaced air and root zone respiration consumed O2. The rate of O2 consumption was 2.7 times greater in the high-N treatment than the low-N treatment. This difference was associated with a 1.8 fold difference in numbers of observed roots. Root growth was only slightly affected by flooding. Leaf growth decreased by 28%, foliage temperature increased 2.3% and apparent photosynthesis decreased by 16%. It is suggested that flooding reduced photosynthetic activity within 2 days while other stress symptoms became apparent after about 6 days. Although this stress was reflected in a trend for decreased plant productivity, the effect of flooding on boll dry mass at harvest was not significant at the level of replication used. The single waterlogging did not cause yield reductions comparable to those observed elsewhere when several waterlogging events were imposed.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Plant and soil 101 (1987), S. 211-221 
    ISSN: 1573-5036
    Keywords: aeration ; calcium ; cotton ; flooding ; magnesium ; manganese ; phosphorus ; potassium ; sodium chloride ; waterlogging
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract A field experiment was conducted to investigate the effects of intermittent waterlogging on the nutrient status of cotton (Gossypium hirsutum cv. Deltapine 61). The crop was grown in a sloping plot of soil in which a gradient of water-table depth ranging from 0.04m above to 0.60m below the soil surface was established during two periods of waterlogging in mid summer and early autumn. The first waterlogging lasted 8 days; the second lasted 16 days. Dry matter increases were less for severely waterlogged plants than for plants with well-aerated root systems during the first flooding, but the increases were similar during the second. Waterlogging impaired uptake of most nutrients by young plants in the first flooding, but had much less effect on nutrient uptake by older plants in the second. Waterlogging consistently reduced concentrations of P and K in the petioles and laminae of young fully-expanded leaves, and severely waterlogged plants were deficient in these nutrients by the end of the first flooding. Mn did not accumulate to toxic levels in waterlogged plants. During each flooding, waterlogged plants gained in total content of all nutrients studied, but the gains of each nutrient, except for Na, were proportionally smaller than for well-aerated plants. Fluxes of K-, Cl- and HPO4- ions in xylem sap exuded from stumps of detopped plants which had been waterlogged were lower than those from plants with well-aerated root systems. Seed cotton yields and concentrations of nutrients in mature bolls were not affected by the two periods of waterlogging. It is concluded that although intermittent waterlogging induced nutrient stress in cotton plants, especially for P and K in young plants before flowering, they recovered with no detrimental effect upon yield.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Weinheim [u.a.] : Wiley-Blackwell
    Materials and Corrosion/Werkstoffe und Korrosion 15 (1964), S. 51-58 
    ISSN: 0947-5117
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: Application of large-diameter pipes made of hard polyethyleneWith the aid of numerous illustrations, the applications of polyethylene pipes of relatively large diameters are surveyed. A special account is given of the advantages which such pipes may offer under different installation conditions. Especially in the Scandinavian countries  -  Norway, Finland and Sweden  -  where pipes are laid in the open even during the winter months, the toughness of hard polyethylene, even at low temperatures, is found to be a particular advantage. A special problem is posed by the need for a reliable jointing of large-diameter pipes. It is shown that, if the necessary conditions are adhered to, and if suitable aids are used, it is possible to obtain reliable butt welds, both between one pipe and another, and between pipe and welding collar. Such welding collars can be made in different ways. For instance, a mould is filled with the aid of an extruder and a rough cast prepared which, after cooling, is machined on a lathe. Pipes made of hard polyethylene are used not only for drinking water pipes but also for special purposes, e. g. cable protection pipes. For this purpose, a special technique, known as jetting method, is sometimes used for laying pipes across water.
    Notes: Anhand einer großen Anzahl van Bildern wird über den Einsatz van Rohren relativ großen Durchmessers aus Hart-Polyäthylen berichtet. Dabei wird auch auf die Vorteile, die solche Rohre unter den verschiedensten Verlegebedingungen bieten, näher eingegangen. Gerade in skandinavischen Ländern wie Norwegen, Finnland und Schweden, wo auch während der Wintermonate Rohrverlegungen im Freien stattfinden, erweist sich die gute Zähigkeit von Hart-Polyäthylen auch in der Kälte von besonderem Vorteil. Ein besonderes Problem stellt die zuverlässige Verbindung von Rohren großen Durchmessers der. Es wird gezeigt, daß bei Einhaltung der erforderlichen Bedingungen und bei Verwendung geeigneter Hilfsgeräte einwandfreie Stumpfschweißungen sowohl der Rohre untereinander als auch von Rohr und Vorschweißbund erzielt werden können. Die Herstellung solcher Vorschweißbunde kann auf verschiedene Arten vorgenommen werden; z. B. wird mit Hilfe eines Extruders eine Form gefüllt und durch Pressen ein Rohling hergestellt, der nach dem Erkalten auf einer Drehbank bearbeitet wird. Neben der Verwendung van Rohren aus Hart-Polyäthylen für Trinkwasserleitungen werden sie auch für Spezialzwecke, wie z. B. Kabelschutzrohre, eingesetzt. Dabei wird in manchen Fällen eine besondere Verlegetechnik beim Durchqueren van Gewässern, das sog. Einspülverfahren, angewandt.
    Additional Material: 36 Ill.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 130 (1972), S. 378-388 
    ISSN: 1432-0878
    Keywords: Arteries ; Children ; Structure ; Pattern of calcification ; Light microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Gross calcifications of the common iliac and internal iliac arteries represent a common finding in newborn children and infants. In both arteries, the calcific deposits regularly appear in certain areas of the arterial luminal surface only, whereas the other parts of the arterial wall remain free of gross lesions even in cases with a pronounced calcification. In the common iliac artery, the lateral wall of the vessel and the adjacent sectors of the anterior and posterior wall represent the predilection site of calcific deposits. In the internal iliac artery, the gross calcifications have been regularly demonstrated in the dorso-medial wall. The predominant localisation of the calcification in these parts of the vessels and its absence in the others depend on the definite structural features of the arterial tube and different affinity for calcium of the individual structural elements. In both iliac arteries, only the primary internal elastic membrane undergoes early calcification. However, unlike the most muscular arteries, this membrane is not developed in the whole arterial circumference of the common iliac and internal iliac arteries, but is absent in large areas of their arterial luminal layer. In these areas, the subendothelial or subintimal elastic layers are formed by the networks of longitudinally arranged elastic fibers or membraneous elastic structures which arise from the elastic networks with the further growth. These elastic elements always stay free of calcific deposits. The structural features found in both iliac arteries may be important for the development of the later pathological changes.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 1434-6079
    Keywords: 31.20.Di ; 34.50.Gb ; 52.20.Hv
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract We have carried out a comprehensive experimental and theoretical investigation of the autoionizing collision systems He*(23 S, 21 S) + He*(23 S). We present high resolution electron energy spectra, obtained with a single He* beam (average relative collision energy 〈E rel〉=1.6 meV) and with crossed He* beams (〈E rel〉〉 =61 meV). The spectra show substantial structure, and under single beam conditions fast oscillations due to the interference of incoming and outgoing heavy particle waves in the entrance channels are observed. Accurate ab initio potential curves for the seven lowest He*—He*(Σ) molecular states have been obtained from a Feshbach projection scheme, and width functions for He*(23 S) + He*(23 S) have been derived by Stieltjes imaging. Based on these ab initio data, detailed quantum mechanical calculations of the electron spectra have been carried out and provide a thorough understanding of the experimentally observed spectral features. Good overall agreement of the calculated spectra with the experimental data is observed. The close coincidence in the positions of the experimental and theoretical peaks, especially for He*(23 S) + He*(23 S), underlines the reliability of the ab initio potentials. In the He*(21 S) + He*(23 S) electron spectrum, the dominant peak is traced to be due to autoionization from the 23Σ+ g molecular state accessed via an avoided crossing. We also present a detailed discussion of the total ionization cross sections σtot and of the fraction σAI/σtot for associative ionization together with a critical comparison with previous work. The ionization probabilities for close collisions in entrance channels, from which autoionization is spin-allowed, are near unity, and therefore the absolute values and the collision energy dependence of the total cross sections simply reflect the long-range behaviour of the excited state potentials.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 366 (1969), S. 43-50 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The nitride-halides UNCl, UNBr and UNJ have been prepared by heating the tetrahalides in a current of ammonia, as well as by reaction of the tetrahalides with uranium nitride. The compounds have been characterized by analysis and their chemical and physical properties.The compounds are isotypic with BiOCl (EO1-type), they are, in addition, structurally related to the corresponding thorium compounds.
    Notes: Die Nitridhalogenide UNCl, UNBr und UNJ wurden durch Erhitzen der Tetrahalogenide im Ammoniakstrom, ferner durch Umsetzung der Tetrahalogenide mit Urannitrid hergestellt und durch Analyse sowie durch ihre chemischen und physikalischen Eigenschaften charakterisiert.Die Verbindungen sind dem BiOCl (EO1) isotyp, sie schließen sich strukturell den entsprechenden Thoriumverbindungen an.
    Additional Material: 5 Tab.
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Sechs verschiedene segmentierte Copolyetherester basierend auf Polybutylenterephthalat als hartem und Oligotetramethylenoxidglykol als weichem Segment wurden untersucht. Der Gewichtsbruch der Hartsegmente lag zwischen 0,26 und 0,72, und die Weichsegmente hatten Molgewichte von entweder 1000 oder 2000. Das Schmelz-, Rekristallisations- und Temperverhalten sowie Relaxationsphanomene wurden untersucht; letzteres mit Hilfe eines Torsionspendels.Die DSC-Daten zeigen, daI3 nur ein kleiner Teil aller Hartsegmente kristallisiert. Sequenzen, die kiirzer oder langer als die mittlere Sequenzlange sind, kristallisieren nicht, sondern bilden zusammen mit den Weichsegmenten eine homogene amorphe Matrix, in die die kristallinen Domanen eingebettet sind. Diese Domanen werden infolge kalten Flusses unter Spannung vollstandig zerstort, bilden sich jedoch bei Temperung der verstreckten Proben wieder aus. Man beobachtet ein exponentielles Anwachsen der Langperiode mit zunehmender Tempertemperatur, wobei der Schmelzpunkt konstant bleibt. Die Sequenzlangenverteilung scheint keinen EinfluB auf das Temperverhalten zu haben.
    Notes: Six different segmented copolyether-esters based on polybutyleneterephthalate as the hard and oligotetramethylene oxide glycols as the soft segments were studied. The weight fraction of the hard segments varied between 0.26 and 0.72 and the soft segment had an average molecular weight of either 1000 or 2000. The melting, recrystallization, and annealing behavior was studied as well as the relaxation behavior via measurement by a torsion pendulum. The DSC-data indicate that only a small fraction of all hard segment sequences crystallize. Sequences shorter or longer than the average sequence length do not crystallize but together with the soft segments form a homogeneous amorphous matrix in which the crystalline domains are embedded. These domains are completely destroyed by cold flow under stress but are formed again on annealing the stretched sample. An exponential increase of the long spacing is observed with increasing annealing temperature without change in melting temperature. The sequence distribution does not seem to influence the annealing behavior.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für die chemische Industrie 78 (1966), S. 1023-1023 
    ISSN: 0044-8249
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für die chemische Industrie 79 (1967), S. 151-152 
    ISSN: 0044-8249
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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