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  • 1
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Geophysical prospecting 27 (1979), S. 0 
    ISSN: 1365-2478
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Geosciences , Physics
    Notes: From gravity it is well known how to determine the excess mass and the horizontal center of mass of the disturbing body. We show that a magnetic body—under rather weak assumptions—possesses excess magnetization and centers of magnetization (both horizontal and vertical), which can be uniquely determined from measurements. It also follows that the vertical center of mass can be uniquely determined from the vertical derivative of the gravity field.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Copenhagen : Munksgaard International Publishers
    Allergy 54 (1999), S. 0 
    ISSN: 1398-9995
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Background: Occupational exposure to Christmas cacti has been reported as a cause of type I allergy. Therefore, the prevalence of immediate-type mucosal and skin reactions related to cactus exposure was studied in 103 employees in a cactus nursery. Methods: The study was based on a questionnaire followed by clinical examination, skin prick tests (SPT) with standard inhalant allergens and cacti, and a histamine-release test (HRT/Refix) using fresh cactus extracts as elicitor. Results: The questionnaire was answered by 84 (82%) of the nursery employees, and 63 (61%) were interviewed and skin prick tested; 58 of these were tested with HRT/Refix. Furthermore, 22 healthy controls were included and tested in vivo and in vitro. Cactus-related contact urticaria and/or rhinoconjunctivitis were reported by 37% of the cactus workers. Based on a combination of positive history, positive SPT, and positive HRT/Refix to cactus, 8% of the cactus workers were allergic to cacti. No noncactus workers or controls were allergic to cacti by these criteria. Testing with fresh cactus material elicited positive SPT and negative HRT/Refix in 27 nursery workers and controls, of whom 12 had immediate-type skin and mucosal symptoms. Conclusions: Christmas and Easter cacti seemed to be able to induce contact urticaria and rhinoconjunctivitis on both an immunologic and a nonimmunologic basis. Personal atopy was associated with positive reactions to cacti.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Aquaculture nutrition 3 (1997), S. 0 
    ISSN: 1365-2095
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Atlantic salmon, Salmo salar L., with mean initial weight of 60 g were fed a diet based on cod muscle meal supplemented with elemental iron, iron sulphate or haem-bound iron in concentrations of 0, 25, 50, 100, 500 and 1500 mg iron kg−1 for 8 weeks. No significant differences in growth or mortality were found, except in fish fed 1500 mg haem iron kg−1, which showed reduced growth. In fish fed diets supplemented with elemental iron below 1500 mg iron kg−1, blood haemoglobin and hepatic iron concentration decreased compared with fish fed the unsupplemented diet. Fish fed diets supplemented with iron sulphate showed increased blood haemoglobin and hepatic iron concentrations between 25 and 100 mg iron kg−1. Fish fed diets supplemented with haem-bound iron showed increased hepatic iron at all dietary iron levels, while blood haemoglobin concentration decreased in the group fed 1500 mg haem iron kg−1. The bioavailability of haem iron relative to sulphate iron was calculated by the slope ratio method to be 239% and 148% using blood haemoglobin and hepatic iron, respectively. Relative bioavailability of elemental iron was zero when dietary supplementation levels were between 25 and 500 mg iron kg−1, while a small part was utilized when 1500 mg elemental iron kg−1 was supplemented.Additions of 500 and 1500 mg haem-bound iron kg−1 resulted in a complete loss of ascorbic acid in these diets. When these groups were discounted, no significant relationship between hepatic iron and hepatic ascorbic acid was found. There was no significant effect of dietary iron on whole-body manganese concentration and only a weak effect on whole-body zinc concentration. No significant correlations between dietary iron and hepatic copper concentration were found in any of the dietary treatments. This study also showed that the level of inorganic iron supplementation may be reduced by inclusion of 20 g blood meal kg−1 in the diet.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Aquaculture nutrition 2 (1996), S. 0 
    ISSN: 1365-2095
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: A study was conducted to determine the dietary iron requirement of fingerling Atlantic salmon Salmo salar L. During the first 4 weeks of the experiment, fish with an initial weight of 5 g were fed a casein–gelatine-based purified diet which contained 11 mg iron kg−1. Thereafter duplicate tanks (200 fish in each) were fed the casein–gelatine purified diets containing supplemental iron levels of 0, 10, 20, 30, 40, 60, 100, 200 or 400 mg iron kg−1 (added as FeSO−4* 7H2O) for 12 weeks. Weight gain, body length and mortality were monitored. Liver iron and ascorbic acid concentration were analysed in addition to whole-body iron, manganese and zinc concentration. Several haematological parameters were also measured.There were no significant differences in weight gain and survival of salmon fed diets containing different iron levels. Haematological values, hepatic and whole-body iron concentrations were, however, significantly affected by the dietary iron content. Liver vitamin C concentration decreased with increasing dietary iron levels. Dietary supplementation with iron significantly reduced whole-body manganese, but no effect of dietary iron on whole-body zinc was found. Based on haematology and hepatic iron concentration, the iron requirement of Atlantic salmon was determined to be between 60 and 100 mg iron kg1.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    [s.l.] : Nature Publishing Group
    Nature 223 (1969), S. 535-537 
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Fig. 1. /5-Galactosidase (a) and transacetylase activities (b) for crude extracts from cells containing no suppressor (o), a class 1 amber suppressor (O), or a class 1 ochre suppressor (+). The increases in OD per mg of protein in the extracts are plotted as a function of substrate-extract reaction ...
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    [s.l.] : Nature Publishing Group
    Nature 173 (1954), S. 541-542 
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] I prepared CH2DBr in about 93 per cent isotopic purity by the direct action of CH2N2 and DBrJin dibutyl ether7. The reagents are difficult to handle on a large scale, and it does not seem possible to avoid exchange with such reactive materials.CH2DBr has now been prepared in high yield by the ...
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Journal of Quantitative Spectroscopy and Radiative Transfer 45 (1991), S. 127-132 
    ISSN: 0022-4073
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Physics
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Rheologica acta 20 (1981), S. 222-230 
    ISSN: 1435-1528
    Keywords: Polypropylene-polyethylene blend ; die swell ; morphology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Zusammenfassung In der vorliegenden Untersuchung werden das Strahlaufweitungsverhalten und die Morphologie von geschmolzenem isotaktischem Polypropylen (PP) und Polyäthylen hoher Dichte sowohl für die reinen Polymeren als auch für deren Mischungen mit 25, 50 und 75 Gewichts-% PP beschrieben. Die Charakterisierung der Morphologie der Schmelzenmischungen und ihrer mittels eines Instron-Kapillarrheometers hergestellten Extrudate erfolgt mit einer mikroskopischen Phasenkontrastmethode. Die Ergebnisse zeigen, daß Schmelzenbereiche, in denen die disperse Phase eine höhere Viskosität besitzt als die kontinuierliche Phase, im Extrudat als kontinuierliche Bereiche erhalten bleiben, wohingegen beim Extrudieren eine Zerstörung dieser Bereiche stattfindet, wenn die kontinuierliche Phase die höhere Viskosität besitzt. Sowohl das Aufweitungs- als auch das Fadenbildungsverhalten der Schmelzenextrudate mit instabilen Bereichen gleicht beim Extrudieren unter hohen Schubspannungen dem Verhalten von Homopolymeren, wohingegen Proben mit stabilen Bereichen sich in signifikanter Weise unterschiedlich verhalten: Die Strahlaufweitung steigt hier bei konstanter Schubspannung mit der Temperatur an, und bei der Verstreckung lassen sich keine stabilen Fäden mehr erhalten.
    Notes: Summary Die swell behaviour and morphology of melt blends of isotactic polypropylene (PP) and high density polyethylene for pure polymers and blends with 25, 50 and 75 weight % PP are described in the present study. A light interference contrast microscopy technique was used for the morphological characterization of melt blends and extrudate samples of the blends obtained with an Instron capillary rheometer. The results indicate that the domains from blends where the dispersed phase has higher viscosity than the continuous phase remain as continuous domains in the extrudate whereas domain destruction takes place when blends where the continuous phase has the higher viscosity are extruded. The die swell behaviour as well as the fiber forming properties of extrudates of melts having unstable domains extruded at high shear stresses resemble the behaviour of homopolymers, whereas samples with stable domains are significantly different, die swell increases with temperature at constant shear stress and stable fibers cannot be obtained after necking.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Marine biology 99 (1988), S. 591-603 
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Effects of benthic macrofauna (Corophium volutator, Hydrobia sp., Nereis virens) on benthic community metabolism were studied over a 65-d period in microcosms kept in either light/dark cycle (L/D-system) or in continuous darkness (D-system). Sediment and animals were collected in January 1986 in the shallow mesohaline estuary, Norsminde Fjord, Denmark. The primary production in the L/D-system after 10 d acted as a stabilizing agent on the O2 and CO2 flux rates, whereas the D-system showed decreasing O2 and CO2 flux throughout the period. Mean O2 uptake over the experimental period ranged from 0.38 to 1.24 mmol m−2 h−1 and CO2 release varied from 0.80 to 1.63 mmol m−2 h−1 in both systems. The presence of macrofauna stimulated community respiration rates measured in darknes, 1.4 to 3.0 and 0.9 to 2.0 times for O2 and CO2, respectively. In contrast, macrofauna lowered primary production. Gross primary production varied from 1.06 to 2.26 mmol O2 m−2 h−1 and from 1.26 to 2.62 mmol CO2 m−2 h−1. The community respiratory quotient (CRQ, CO2/O2) was generally higher in the begining of the experiment (0–20 d, mean 1.89) than in the period from Days 20 to 65 (mean 1.38). The L/D-system exhibited lower CRQ (ca. 1) than the D-system. The community photosynthetic quotient varied for both net and gross primary production from 0.64 to 1.03, mean 0.81. The heterotrophic D-system revealed a sharp decrease in the sediment content of chlorophyll a as compared to the initial content. In the autotrophic L/D-system, a significant increase in chlorophyll a concentration was observed in cores lacking animals and cores with C. volutator (The latter species died during the experiment). Due to grazing and other macrofauna activities other cores of the L/D-system exhibited no significant change in chlorophyll a concentration. Community primary production was linearly correlated to the chlorophyll a content in the 0 to 0.5 cm layer. Fluxes of DIN (NH4 ++NO2 −+NO3 −) did not reveal significant temporal changes during the experiment. Highest rates were found for the cores containing animals, mainly because of an increased NH4 + flux. The release of DIN decreased significantly due to uptake by benthic microalgae in the L/D-system. No effects of the added macrofauna were found on particulate organic carbon (POC), particulate organic nitrogen (PON), total carbon dioxide (TCO2) and NH4 + in the sediment. The ratio between POC and PON was nearly constant (9.69) in all sediment dephts. The relationship between TCO2 and NH4 + was more complex, with ratios below 2 cm depth similar to those for POC/PON, but with low ratios (3.46) at the sediment surface.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Zeitschrift für angewandte Mathematik und Physik 48 (1997), S. 165-170 
    ISSN: 0044-2275
    Keywords: Key words.Thermal radiative heat transport, Marshak boundary condition, recurrence formulae.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics , Physics
    Notes: Abstract. The Marshak boundary condition is applied in the one-dimensional case of thermal radiative heat transport solved by the spherical harmonics method. Recurrence formulae for the Marshak boundary condition are derived for the cases where the absorbing, emitting and scattering material is limited by diffusely emitting, partly diffusely and partly specularly reflecting walls. The recurrence formulae are applied to an example with good results.
    Type of Medium: Electronic Resource
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