116 research outputs found

    GENERALIZATION OF THE UP-TO DATE THEORY OF PLASTICITY FOR THE DESCRIPTION OF CREEP STRAIN

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    The papers [4,11] contain the description of the synthesis of slip conception and flow theory in accordance with the ideas of Koiter [7]. The present work contains comments to the mentioned [4,11] up-to-date theory of plasticity and its generalization for the description of creep strain

    Study to establish cost projections for production of Redox chemicals

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    A cost study of four proposed manufacturing processes for redox chemicals for the NASA REDOX Energy Storage System yielded favorable selling prices in the range 0.99to0.99 to 1.91/kg of chromic chloride, anhydrous basis, including ferrous chloride. The prices corresponded to specific energy storage costs from under 9to9 to 17/kWh. A refined and expanded cost analysis of the most favored process yielded a price estimate corresponding to a storage cost of $11/kWh. The findings supported the potential economic viability of the NASA REDOX system

    Stakeholders, Green Manufacturing, and Practice Performance: Empirical Evidence from Chinese Fashion Businesses

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    This study explores the relationship among stakeholders, green manufacturing, and practice performance in the fashion business in China and focuses on assisting companies to enhance environmental awareness and green manufacturing practices. We collect research data by developing questionnaires for various Chinese enterprises. A five-point Likert scale is adopted to enable respondents to indicate the extent to which they agree with the items. Through tests and analyses, the questionnaire is validated as reliable, the structural equation model has a good fitting degree, and hypotheses are proved true. Specifically, corporate stakeholders have a significant positive impact on green manufacturing and practice performance, and green manufacturing has a significant positive impact on practice performance in the context of Chinese fashion businesses. Moreover, corporate stakeholders can have a positive impact on practice performance through green manufacturing. We also propose some policy implications, including implementing compulsive policies and regulations and encouraging and establishing preferential policies, such as tax concessions. Moreover, enterprises should actively strive to improve green manufacturing technology and management level to ensure the smooth implementation of green manufacturing practices. To retain sustained earnings and development, green manufacturing should be the bottom line of involved firms. We also emphasize that the importance of corporate stakeholders should be promoted in consideration of enterprises’ practice performance and future development

    Sustainability centres and fit: how centres work to integrate sustainability within business schools

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    For nearly as long as the topic of sustainable business has been taught and researched in business schools, proponents have warned about barriers to genuine integration in business school practices. This article examines how academic sustainability centres try to overcome barriers to integration by achieving technical, cultural and political fit with their environment (Ansari, Fiss, & Zajac, 2010). Based on survey and interview data, we theorise that technical, cultural and political fit are intricately related, and that these interrelations involve legitimacy, resources and collaboration effects. Our findings about sustainability centres offer novel insights on integrating sustainable business education given the interrelated nature of different types of fit and misfit. We further contribute to the literature on fit by highlighting that incompatibility between strategies to achieve different types of fit may act as a source of dynamism

    Whole-genome sequences of Malawi cichlids reveal multiple radiations interconnected by gene flow.

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    The hundreds of cichlid fish species in Lake Malawi constitute the most extensive recent vertebrate adaptive radiation. Here we characterize its genomic diversity by sequencing 134 individuals covering 73 species across all major lineages. The average sequence divergence between species pairs is only 0.1-0.25%. These divergence values overlap diversity within species, with 82% of heterozygosity shared between species. Phylogenetic analyses suggest that diversification initially proceeded by serial branching from a generalist Astatotilapia-like ancestor. However, no single species tree adequately represents all species relationships, with evidence for substantial gene flow at multiple times. Common signatures of selection on visual and oxygen transport genes shared by distantly related deep-water species point to both adaptive introgression and independent selection. These findings enhance our understanding of genomic processes underlying rapid species diversification, and provide a platform for future genetic analysis of the Malawi radiation

    Cyclic ADP-ribose and NAADP: fraternal twin messengers for calcium signaling

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    Widespread occurrence in animal tissues of an enzyme catalyzing the conversion of NAD+ into a cyclic metabolite with intracellular Ca2+-mobilizing activity

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    A metabolite with intracellular Ca2+-mobilizing activity can be produced by incubating NAD+ with extracts from sea urchin eggs. Structural determination indicates it is a cyclized ADP-ribose, and we have proposed cyclic ADP-ribose as a common name for it. In this study, we addressed the question of how wide-spread is the occurrence of the synthesizing enzyme for this NAD+ metabolite. Incubation of NAD+ with extracts prepared from rabbit liver resulted in a progressive increase in Ca2+ release activity which was monitored by a biological assay using sea urchin egg homogenates. The half-maximal concentration of NAD+ required was about 1 mM. The reaction was stereospecific, and the extracts were sensitive to protease treatment and heat, as well as alkaline pH of about 9.0, indicating the reaction was catalyzed by a protein. The active metabolite was purified by an identical high pressure liquid chromatography (HPLC) procedure used for cyclic ADP-ribose. Functionally, the liver metabolite behaved similarly to cyclic ADP-ribose. Both discharged the same Ca2+ stores in sea urchin egg homogenates with the same half-maximal effective concentrations. Both were active in inducing the cortical exocytosis reaction when microinjected into sea urchin eggs. That they are indeed identical compounds was demonstrated by structural analyses showing that they coeluted on a Partisil 5 SAX HPLC column and had identical 1H NMR spectra. Mass spectrometry indicated a mass of 540.0529 for the molecular ion (M - H)- of the liver metabolite, which was identical to within 0.74 ppm of cyclic ADP-ribose. Furthermore, their collisional activated decomposition mass spectra were virtually superimposable. Extracts from rabbit brain, heart, spleen, and kidney were all active in producing similar Ca2+-releasing metabolites which could be isolated by the same HPLC procedure and had similar elution times on both the mixed mode and the Partisil 5 SAX column. It is therefore apparent that the synthesizing enzyme for cyclic ADP-ribose is a very common enzyme.link_to_subscribed_fulltex

    Analytic investigation of the stress-strain relation for an arbitrary loading trajectory

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