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  • 1
    ISSN: 1013-9826
    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: Homogenization is an important analysis approach of composite materials with structural hierarchy and can give the prediction of macroscopic properties of the composites. There are many homogenization theories and methods. The present paper discusses applications of some homogenization approaches including both direct and mathematical homogenizations for the analysis of anisotropic composites with periodic microstructures. The macroscopic properties of thecomposite are predicted by the direct homogenization and the mathematical homogenisation method. The periodic boundary conditions of a representative volume element are implemented by a transformation method of the degrees of freedom. The numerical results are demonstrated for two model composites. The study shows that these two homogenization methods gave the same resultsfor the macroscopic elastic stiffness of the composites although they are of different mathematical forms and different operation procedures
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  • 2
    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: The turbo air classifier is one of the most widely used equipment in powder classification. The complex flow behaviour inside it, however, prevents material experiments from providing information about its internal separation mechanisms. A study of the interaction of structural variables is therefore undertaken examining air flow behaviour, specifically the air flow between the blades of the rotor cage. The investigation of these flow field characteristics made use of the computational fluid dynamics (CFD) to simulate the air flow in the classifier. It was found that the inlet velocity of the turbo air classifier and the rotary speed of the rotor cage are two of the dominating, non-structural factors that affect velocity distributions in the region between the rotor cage blades. Once the inlet velocity settles, a critical rotary speed must be present to smoothen the flow field between the blades, resulting in an excellent classification performance.Three-dimensional velocity measurements of the region between the blades by laser Doppler velocimeter (LDV) were performed to test the results of the flow field simulation. This revealed that when inlet velocity is invariable, the velocity distributions in the region between the blades are at its most symmetric with the critical rotary speed of the rotor cage making it more favourable for classification. The velocity measurement results are likewise in good agreement with the results of the flow field simulation.Newly structured rotor cages are also simulated and compared with a conventional turbo air classifier, air flow in the newly structured model is smoother. The distributions of radial and tangential velocities are more symmetric and the trend of the rotating vortex between the blades attenuates, particularly when the rotary speed is high. The newly structured rotor cages can therefore achieve higher classification performances
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  • 3
    ISSN: 1573-5044
    Keywords: anther culture ; Brassica oleracea ; cauliflower ; culture conditions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Experiments on three autumn-heading cauliflower genotypes (2 hybrids and a genotype selected from a population) were conducted to study different factors affecting anther culture. Culture conditions of the donor plants proved to be important: the best results were obtained during spring in a greenhouse where the temperature was maintained between 10 and 20°C. Overall winter and spring seemed more suitable than summer and early autumn for culture establishment. The optimal bud development stage depended on the genotype: for the hybrid 702, the greatest number of embryos for 100 plated anthers was obtained at the uninucleate pollen stage of the microspores; for V23.2 and 703, the optimal stage of the buds corresponded to the first mitotic division. Sucrose proved to be the best carbon supply for embryogenesis with an optimal concentration of 140 g l-1. The addition of a cytokinin (BAP) in the medium led to lower embryo production, and this negative effect increased when the hormone concentration in the medium increased. The use of liquid medium and a dark incubation period immediately after the high temperature treatment were favourable for embryogenesis.
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Reliable computing 1 (1995), S. 265-274 
    ISSN: 1573-1340
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science , Mathematics
    Description / Table of Contents: Abstract INTBIS—грошедший ушательное тестирование пакет программного обеспения, использюшй интервальный метод Ньютона и обобшенный метод половинного деления гля нахождения всех численных решений систем нелинейных уравнений. Благодаря тому что INTBIS использует интервальные вычисления, получаемые им результаты гарантированно содержат все решения. Для эффективного решения очень больших нелинейных систем на параллельном векторном компьюотере необходимо максимально использобать особенности архитектуры машины. В настояшэй работе описаны реализации INTBIS для больших нелинейных систем на суперкомпьютере Сгау Y-MP Сначала представлена прямая реализация INTBIS для комппьгеров Сгау, а затем излагаются результаты работы по оптимизации INTBIS для Сгау Y-MP
    Notes: Abstract INTBIS is a well-tested software package which uses an interval Newton/generalized bisection method to find all numerical solutions to nonlinear systems of equations. Since INTBIS uses interval computations, its results are guaranteed to contain all solutions. To efficiently solve very large nonlinear systems on a parallel vector computer, it is necessary to effectively utilize the architectural features of the machine In this paper, we report our implementations of INTBIS for large nonlinear systems on the Cray Y-MP supercomputer. We first present the direct implementation of INTBIS on a Cray. Then, we report our work on optimizing INTBIS on the Cray Y-MP
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  • 5
    ISSN: 1573-1340
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science , Mathematics
    Description / Table of Contents: Abstract Интервальный метод Ньютона и обобщенный метод половинного деления гарантированно находят все численные решения в заланной области. Как анализ вычислительной сложности, гак и численные зксперимемты показали, что решение соответствующей интервальной линейной системы, полученной интервальными методами Ньютона, может потребовать значительного объема вычислений (особенно если нелинейная система велика по размерам) На практике системы нелинейных уравнений большой размерности нередко сводятся к разреженным интервальным матрицам Якоби. В настоящей работе предлагается обобщенная индексированная схема памяти для хранения разреженных интервальных матриц, а затем вводится итеративный интервальный линейный решатель, пснользуюший эту схему Ожидается, что предложенный обобшенный итеративный итеративный интервальный линейный решатель повысит обшую производительность методов Ньютона и обобщенного метода половинного деления для разреженных матриц Якоби В разделе 1 кратко описаны интервальные методы Ньютона. В разделе 2 рассматриваются некоторые используемые в настоящее время схемы памяти для разреженных систем В
    Notes: Abstract Interval Newton/Generalized Bisection methods reliably find all numerical solutions within a given domain. Both computational complexity analysis and numerical experiments have shown that solving the corresponding interval linear system generated by interval Newton's methods can be computationally expensive (especially when the nonlinear system is large). In applications, many large-scale nonlinear systems of equations result in sparse interval jacobian matrices. In this paper, we first propose a general indexed storage scheme to store sparse interval matrices We then present an iterative interval linear solver that utilizes the proposed index storage scheme It is expected that the newly proposed general interval iterative sparse linear solver will improve the overall performance for interval Newton/Generalized bisection methods when the jacobian matrices are sparse. In section 1, we briefly review interval Newton's methods. In Section 2, we review some currently used storage schemes for sparse systems. In Section 3, we introduce a new index scheme to store general sparse matrices. In Section 4, we present both sequential and parallel algorithms to evaluate a general sparse Jacobian matrix. In Section 5, we present both sequential and parallel algorithms to solve the corresponding interval linear system by the all-row preconditioned scheme. Conclusions and future work are discussed in Section 6.
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  • 6
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 0894-9166
    Keywords: composite materials ; cyclic loading ; elasto-plasticity ; constitutive relations
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract The clasto-plastic constitutive behaviors of continuous fiber reinforced composites under cyclic loadings are studied by the micromechanics method in which the equal-strain model is used in the fiber direction, the equal-stress model in the other directions. It is supposed that fiber is linearly elastic and matrix is clastic-viscoplastic. The constitutive equations of the matrix are described by Bodner-Partom's unified constitutive theory. Boron/Aluminum composite, as an example, is investigated in detail for an understanding of the stress-strain relations and initial yield behaviors of metal matrix composites. Present results are compared with the experimental data.
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  • 8
    ISSN: 1432-1203
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. The identification of genomic rearrangements involving more than 0.5 kb of the BRCA1 gene has confirmed a more complex mutation spectrum than was initially appreciated. Genomic rearrangements in BRCA1 represent 15% of all mutations in a group of French and American breast and ovarian cancer families and 36% of all mutations in a group of Dutch families. The rearrangements described to date range in size from 510 bp to 23.8 kb, are found throughout the gene, and are most frequently attributable to homologous recombination. We describe the identification of rearrangements in two breast and ovarian cancer families that involve 3.4 and 11.5 kb of the BRCA1 gene and span multiple exons but maintain the reading frame. Both gene rearrangements appear to result from Alu-mediated homologous recombination and have been detected by using a combination of protein truncation analysis and Southern blot analysis. These rearrangements result in the loss of amino acids that lie at the carboxy-terminus of the protein and that have previously been shown to have functional significance. Because these rearrangements result in the deletion of exons but maintain the reading frame, they may provide insights into specific regions and amino acids that have functional significance for the BRCA1 protein.
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  • 9
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    Berlin: Deutsches Institut für Wirtschaftsforschung (DIW)
    Publication Date: 2016-06-22
    Description: In 1986 German federal parental leave and benefit policy was expanded in several ways, extending the potential duration of leave from six to ten months and paying child-rearing benefits to all new mothers regardless of their employment status before childbirth. The potential duration has increased four times since 1986 and stood at 18 months in 1991 and three years starting in 1992. This study uses log-wage difference regressions to examine the effect of leave taken by the mother on wage growth for two 5-year periods, 1984-1989 and 1989-1994. In each of the five-year periods, taking maternity leave was found to have a significant negative effect on wage growth. Point estimates imply that each month of maternity leave reduced wage growth by 1.5 percent over five years. In addition, for the second five-year period only, mothers experienced lower wage growth if they chose to stay at home rather than return to work when the allowable leave period expired: from 1989 to 1994, a half-year out of the labor force after the end of the leave period lowered wage growth by an additional 15 percent over five years.
    Keywords: D1 ; J3 ; ddc:330 ; Parental leave ; child rearing benefits ; women`s pay ; wage growth ; Erziehungsurlaub ; Frauenarbeitslohn ; Mütter ; Lohndifferenzierung ; Schätzung ; Deutschland
    Repository Name: EconStor: OA server of the German National Library of Economics - Leibniz Information Centre for Economics
    Language: English
    Type: doc-type:workingPaper
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  • 10
    ISSN: 1399-0047
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Notes: Meningococcal meningitis is a severe childhood disease which often results in significant disability or death. Two major etiological agents of meningitis are the group B meningococci and capsular type K1 E. coli. The virulence of these organisms is attributable to structural mimicry between their common α(2–8)-polysialic acid capsular polysaccharide and human tissue antigens, which allows the bacteria to evade immune surveillance. There is currently no effective vaccine to protect against this infection. It has been demonstrated that the capsular polysaccharide of the bacteria can adopt a unique `antigenic conformation'. This antigenic conformation has formed the basis for the development of an N-propionylated polysialic acid vaccine. Immunization trials in mice with this vaccine show the production of two groups of antibodies, of which only N-propionylated polysialic acid-specific were protective. Knowledge of the structure of the antigen-binding site which recognizes the protective epitope is essential to determining the antigenic conformation of the polysaccharides, and is a critical aspect in understanding and improving the action of potential vaccines. The antigen-binding fragments (Fab) of one protective (13D9) and one non-protective (6B9) monoclonal antibody specific for the capsular polysaccharides of group B meningococci have been crystallized and have undergone preliminary X-ray diffraction analysis. Both crystals are observed to scatter X-rays to approximately 1.7 Å resolution at the A1 station at the Cornell High-Energy Synchrotron Source. 13D9 has an orthorhombic unit cell with a = 41.8, b = 102.3, c = 134.7 Å, with space group P212121. Fab 6B9 has an orthorhombic unit cell with a = 89.6, b = 132.0 and c = 36.9 Å, with space group P21212.
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