496 research outputs found

    High purity silica reflective heat shield development

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    A hyperpure vitreous silica material is being developed for use as a reflective and ablative heat shield for planetary entry. Various purity grades and forms of raw materials were evaluated along with various processing methods. Slip casting of high purity grain was selected as the best processing method, resulting in a highly reflective material in the wavelength bands of interest (the visible and ultraviolet regions). The selected material was characterized with respect to optical, mechanical and physical properties using a limited number of specimens. The process has been scaled up to produce a one-half scale heat shield (18 in. dia.) (45.72 cm) for a Jupiter entry vehicle. This work is now being extended to improve the structural safety factor of the heat shield by making hyperpure silica material tougher through the addition of silica fibers

    High purity silica reflective heat shield development

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    Measurements were made of reflectance in the vacuum ultraviolet down to 0.15 micron. Scattering coefficients (S) and absorption coefficients (K) were also measured. These coefficients express the optical properties and are used directly in a thermodynamic analysis for sizing a heat shield. The effect of the thin silica melt layer formed during entry was also studied from the standpoint of trapped radiant energy

    Achieving sustainability in global sourcing: towards a conceptual framework

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    Purpose This paper aims to set out the development, based on the extant literature, an integrated conceptual framework for the emergent field of sustainable global sourcing (GS) that synthesizes its antecedents, GS practices and sustainable performance. Design/methodology/approach Conceptual theory building combined with content analysis is used to develop a framework and propositions representing a middle-range theory of sustainable GS. A literature review of the 89 most influential papers is followed by a further discussion based on the resource orchestration perspective (ROP) to advance an integrated conceptual framework. Findings Three main themes are identified from the literature as antecedents, GS practices and sustainable performance, with each theme being detailed in a variety of constructs. Based on the ROP, the relationships between these constructs are revealed, and therefore, an integrated conceptual framework is advanced via three sets of propositions in recourse orchestration breadth, recourse orchestration depth and resource orchestration evolution, respectively. Eight directions for future research are further proposed. Originality/value First, this study provides a comprehensive framework for future study in the emergent field of sustainable GS. Second, the authors contribute to theory development by proposing a ROP to explore the GS practices towards sustainability. Third, the future research directions we proposed can benefit scholars interested in the overlapping areas of GS and sustainability

    Evaluation of One or Two Lutalyse Injections for Estrous Synchronization in Beef Cattle

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    Researchers have been attempting to control estrous cycles in animals for the last 50 years. For the past several years, there has been considerable interest in the use of Lutalyse for estrous synchronization in beef cattle. For synchronization and artificial insemination to be successful, quality management and nutrition programs must be utilized. Some individual reports have indicated low reproductive performance can be accounted for by noncycling cows, poor management and semen handling techniques efficiency. This study includes data from the 1980, 1981 and 1982 breeding seasons using Lutalyse to synchronize estrous in beef cattle. The purpose of this research was to evaluate the effectiveness of Lutalyse on beef cattle using a single Lutalyse injection compared to two injections given 11 days apart

    Archetypes of sourcing decision-making: the influence of contextual factors on consensus, argumentation and cabal

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    Purpose The purpose of this paper is to develop taxonomy of sourcing decision-making (SDM) archetypes and explore how different contextual factors influence these archetypes when global sourcing of complex components is considered a viable option. Design/methodology/approach A multiple case study approach with five in-depth cases is employed. In total, 19 interviews as well as publicly available and internal data from large buying firms headquartered in Austria and Germany were collected and analyzed. Findings The results reveal three different SDM archetypes which are described in detail (i.e. “consensus,” “argumentation” and “cabal”). Furthermore, it is found that these archetypes are mainly influenced by three contextual factors: sourcing maturity, product complexity and leadership style. The final model comprises six propositions which illustrate how these contextual factors determine companies’ SDM archetypes. Research limitations/implications The study contributes to theory development at the intersection of organizational buying behavior and the (global) SDM literature. Thereby, it answers the call for more rigorous investigation of the influence of contextual factors on SDM processes. Practical implications The findings enable practitioners to better understand and consequently manage SDM processes and their outcomes. By supporting decision-makers in identifying SDM archetypes, this study allows sourcing managers and teams to make better decisions by avoiding problems that occur in situations in which the preferred decision-making type would result in suboptimal decisions. Originality/value The study provides a first step toward taxonomy of SDM archetypes and is among the first that explores their underlying contextual factors

    Future challenges for pharmaceutical supply chains

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    The pharmaceutical industry is facing an era of fundamental transformation, with new products, markets, and regulations requiring changes to governance, risk and supply chain management. These represent both threats and opportunities to the industry, for those who are able to harness developments. Through the provision of example scenarios, this report aims to provide pharmaceutical supply chain managers with the necessary information to help them find the right strategic solutions for their companies over the next ten years. Based on a thorough review of current practical and academic literature, the research team identified twelve future key developments with the potential to impact pharmaceutical supply chains over the next ten years (2015-2025). Based on assessments by 30 European pharmaceutical managers, the report provides analysis of the probability and impact of each development on pharmaceutical supply chains. It scopes the extent to which pharmaceutical supply chain managers welcome and feel able to influence each development. The authors of the report are Prof. Dr. Constantin Blome, University of Sussex, UK and GSK Vaccines Chaired Professor at Université catholique de Louvain, Belgium, as well as Martin Schleper and Hannes Hofmann from EBS University, Germany

    Antecedents of green supplier championing and greenwashing: an empirical study on leadership and ethical incentives

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    Buying firms are increasingly confronted with compliance scandals in their upstream supply chain, for which they are held accountable by their stakeholders. Purely symbolic practices, typically referred to as greenwashing, as well as substantive practices, such as green supplier championing, are thus receiving widespread attention in business practices and academia alike. In this study, we reveal the impact of two opposing leadership dimensions following the concepts of ethical and transactional leadership as antecedents for green supplier championing and greenwashing. We particularly address whether these antecedents have a complementary or a counterproductive effect on green supplier championing and greenwashing. Furthermore, we investigate the complementary impact of incentives and the two leadership styles on achieving sustainability behavior. The resulting model is tested using a path analysis based on a data set of 118 firms located in Germany. We find support for the positive impact of ethical leadership on green supplier championing but also a non-significant negative impact on greenwashing. Greenwashing is significantly impacted by leadership styles reflecting obedience to authority, and further moderated by ethical incentives. Interestingly, ethical incentives do not moderate the impact of ethical leadership on green supplier championing. Finally, we discuss implications for theory and business practice

    PSS25 Validation of the Patient Benefit Index (PBI) for the Assessment of Patient-Defined Benefit in the Treatment of Psoriasis

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    Mating and Management Systems for Commerical Beef Production

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    Recently there has been increased utilization of exotic cattle to increase production in beef herds. Larger calves at weaning and slaughter have resulted due to increased mothering ability and frame size. Hereford-Angus cows have been used extensively in South Dakota and have performed well under local conditions. This study was designed to compare reproductive performance and calf production of S x A and H x A crossbred cows under range conditions. Feedlot performance and carcass beef production have also been evaluated

    Can Alfalfa Be Hayed and Grazed

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    A study established at Cottonwood in 1981 is being evaluate to compare 10 grazing alfalfa varieties plus two hay types in three treatment combinations involving grazing and haying
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