151 research outputs found

    Casimir Effects: An Optical Approach I. Foundations and Examples

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    We present the foundations of a new approach to the Casimir effect based on classical ray optics. We show that a very useful approximation to the Casimir force between arbitrarily shaped smooth conductors can be obtained from knowledge of the paths of light rays that originate at points between these bodies and close on themselves. Although an approximation, the optical method is exact for flat bodies, and is surprisingly accurate and versatile. In this paper we present a self-contained derivation of our approximation, discuss its range of validity and possible improvements, and work out three examples in detail. The results are in excellent agreement with recent precise numerical analysis for the experimentally interesting configuration of a sphere opposite an infinite plane.Comment: Minor corrections. Submitted to Nucl. Phys.

    E-retailing ethics in Egypt and its effect on customer repurchase intention

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    The theoretical understanding of online shopping behaviour has received much attention. Less focus has been given to the formation of the ethical issues that result from online shopper interactions with e-retailers. The vast majority of earlier research on this area is conceptual in nature and limited in scope by focusing on consumers’ privacy issues. Therefore, the purpose of this paper is to propose a theoretical model explaining what factors contribute to online retailing ethics and its effect on customer repurchase intention. The data were analysed using variance-based structural equation modelling, employing partial least squares regression. Findings indicate that the five factors of the online retailing ethics (security, privacy, non- deception, fulfilment/reliability, and corporate social responsibility) are strongly predictive of online consumers’ repurchase intention. The results offer important implications for e-retailers and are likely to stimulate further research in the area of e-ethics from the consumers’ perspective

    Investigating the role of customers’ perceptions of employee effort and justice in service recovery

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    Purpose: The purpose of this paper is, first, to identify the relationship, if any, between customers’ perceptions of justice (functional element) and employee effort (symbolic element) and their effects on satisfaction and loyalty in the context of service recovery and, second, to determine the impact of cross-cultural differences on these relationships. Design/methodology/approach: Survey data from actual customers were gathered in three countries (n = 414) and analyzed using structural equation modeling to test the proposed hypotheses. Findings: The results demonstrate the role of the constructs of perceived employee effort and perceived justice in influencing post-recovery satisfaction and loyalty across cultures. While perceived justice is valued across cultures, customers from feminine (masculine) cultures require more (less) employee effort to influence post-recovery satisfaction positively. Customers from low (high) uncertainty cultures are more (less) willing to give the provider another chance after a service recovery. Research limitations/implications: The study shows that both functional and symbolic elements of service recovery are important determinants of customer satisfaction and loyalty and that their influence can be significant in a cross-cultural context. Practical implications: International service managers must consider the nature of cultural differences in their markets to develop and implement tailored recovery strategies that can result in satisfied customers. Originality/value: This study is the first to integrate the functional and symbolic elements of service recovery, their impact on customers’ behavioral responses and the influence of cultural variations

    Effect of compost-, sand-, or gypsum-amended waste foundry sands on turfgrass yield and nutrient content

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    To prevent the 7 to 11 million metric tons of waste foundry sand (WFS) produced annually in the USA from entering landfi lls, current research is focused on the reuse of WFSs as soil amendments. Th e eff ects of diff erent WFS-containing amendments on turfgrass growth and nutrient content were tested by planting perennial ryegrass (Lolium perenne L.) and tall fescue (Schedonorus phoenix (Scop.) Holub) in diff erent blends containing WFS. Blends of WFS were created with compost or acid-washed sand (AWS) at varying percent by volume with WFS or by amendment with gypsum (9.6 g gypsum kg–1 WFS). Measurements of soil strength, shoot and root dry weight, plant surface coverage, and micronutrients (Al, Fe, Mn, Cu, Zn, B, Na) and macronutrients (N, P, K, S, Ca, Mg) were performed for each blend and compared with pure WFS and with a commercial potting media control. Results showed that strength was not a factor for any of the parameters studied, but the K/Na base saturation ratio of WFS:compost mixes was highly correlated with total shoot dry weight for perennial ryegrass (r = 0.995) and tall fescue (r = 0.94). Th is was further substantiated because total shoot dry weight was also correlated with shoot K/Na concentration of perennial ryegrass (r = 0.99) and tall fescue (r = 0.95). A compost blend containing 40% WFS was determined to be the optimal amendment for the reuse of WFS because it incorporated the greatest possible amount of WFS without major reduction in turfgrass growth

    Progress towards ignition on the National Ignition Facility

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    The Sample Analysis at Mars Investigation and Instrument Suite

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    Implantation Metastasis into an Anal Fistula

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