367 research outputs found

    Mechanical properties of MWPECVD diamond coatings on Si substrate via nanoindentation

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    The mechanical properties of polycrystalline diamond coatings with thickness varying from 0.92 to 44.65 Ī¼m have been analysed. The tested samples have been grown on silicon substrates via microwave plasma enhanced chemical vapour deposition from highly diluted gas mixtures CH4ā€“H2 (1% CH4 in H2). Reliable hardness and elastic modulus values have been assessed on lightly polished surface of polycrystalline diamond films. The effect of the coating thickness on mechanical, morphological and chemical-structural properties is presented and discussed. In particular, the hardness increases from a value of about 52 to 95 GPa and the elastic modulus from 438 to 768 GPa by varying the coating thickness from 0.92 to 4.85 Ī¼m, while the values closer to those of natural diamond (H=103 GPa and E=1200 GPa) are reached for thicker films (N5 Ī¼m). Additionally, the different thickness of the diamond coatings permits to select the significance of results and to highlight when the soft silicon substrate may affect the measured mechanical data. Thus, the nanoindentation experiments were made within the range from 0.65% to 10% of the film thickness by varying the maximum load from 3 to 80 mN. Ā© 2010 Elsevier B.V. All rights reserve

    Validating Expert Systems: A Demonstration Using Personal Choice Expert, a Flexible Employee Benefit System

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    A method for validating expert systems, based on validation approaches from psychology and Turing\u27s ā€œimitation game,ā€ is demonstrated using a flexible employee benefits expert system. Psychometric validation has three aspects: the extent to which the system and expert decisions agree (criterionrelated validity), the inputs and processes used by experts compared to the system (content validity), and differences between expert and novice decisions (construct validity). If these criteria are satisfied, then the system is indistinguishable from experts for its domain and satisfies the Turing Test. Personal Choice Expert (PCE) was designed to help employees of a Fortune 500 firm choose benefits in their flexible benefits system. Its recommendations do not significantly differ from those given by independent experts. Hence, if the system-independent expert agreement (criterion-related validity) were the only standard, PCE could be considered valid. However, construct analysis suggests that re-engineering may be required. High intra-expert agreement exists only for some benefit recommendations (e.g., dental care and long-term disability) and not for others (e.g., short-term disability, accidental death and dismemberment, and life insurance). Insights offered by these methods are illustrated and examined

    The Genetics Journey: A Case Report of a Genetic Diagnosis Made 30 Years Later

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    Mandibulofacial dysostosis with microcephaly (MFDM) is a rare autosomal dominant condition that was first described in 2006. The causative gene, EFTUD2, identified in 2012. We report on a family that initially presented to a pediatric genetics clinic in the 1980s for evaluation of multiple congenital anomalies. Reā€evaluation of one member thirty years later resulted in a phenotypic and molecularly confirmed diagnosis of MFDM. This familyā€™s clinical histories and the novel EFTUD2 variant identified, c.1297_1298delAT (p.Met433Valfs*17), add to the literature about MFDM. This case presented several genetic counseling challenges and highlights that ā€œthe patientā€ can be multiple family members. We discuss testing considerations for an unknown disorder complicated by the time constraint of the patientā€™s daughterā€™s pregnancy and how the diagnosis changed previously provided recurrence risks. Of note, 1) the 1980s clinic visit letters provided critical information about affected family members and 2) the patientā€™s husbandā€™s internet search of his wifeā€™s clinical features also yielded the MFDM diagnosis, illustrating the power of the internet in the hands of patients. Ultimately, this case emphasizes the importance of reā€evaluation given advances in genetics and the value of a genetic diagnosis for both patient care and risk determination for family members.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/147210/1/jgc40894.pd

    Concurrent Outbreak of Norovirus Genotype I and Enterotoxigenic Escherichia coli on a U.S. Navy Ship following a Visit to Lima, Peru

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    An outbreak of norovirus (NoV) genotype I and Enterotoxigenic Escherichia coli (ETEC) occurred among US Navy Ship personnel following a visit to Lima, Peru, in June 2008. Visiting a specific area in Lima was significantly associated with illness. While ETEC and NoV are commonly recognized as causative agents of outbreaks, co-circulation of both pathogens has been rarely observed in shipboard outbreaks

    Human Resource Functioning in an Information Society: Practical Suggestions and Future Implications

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    This paper explores the state human resources management in an information society. As technology rapidly changes organizations and human resources professionals need to be mindful of the impact that can have on the every day operations in human resources departments. As human resource management is involved in the process of recruitment, selection, and retention of new and current employees, they can play a significant role in maintaining a competitive advantage in the knowledge-based market. Thus, the purpose of this article is to provide an overview of the practical and strategic steps that those in the human resources field can take to facilitate success in this changing economy, as well as to warn against the implications and consequences of failing to meet these important challenges.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

    The Influence of Organizational Context on Quitting Intention

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    This study uses multilevel methods to investigate the effects of organizational context on job satisfaction and quitting intention among staff working in long-term mental health care settings. Two types of organizational features are examined: group job satisfaction and structural features of the work unit (unit size, workload, and level of client functioning on the unit). A review of the organizational literature reveals that most empirical research has investigated job satisfaction at the individual level of analysis rather than the group level. The authors argue that the affective context of a group has real and measurable consequences for individual attitudes and behavior, independent of individual attitudes toward the job. Using multilevel modeling, study findings support the premise that group job satisfaction exercises effects on intention to quit independent of individualsā€™ dispositions toward their jobs. These effects are both direct and interactive. The findings underscore the importance of affective context in shaping individual attitudes and behavioral intentions.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68775/2/10.1177_0164027599212003.pd

    Worker Characteristics and Wage Differentials: Evidence from a Gift-Exchange Experiment

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    There is ample empirical evidence indicating that a substantial fraction of the population exhibits social preferences. Recent work also shows that social preferences influence the effectiveness of incentives in labor relations. Hence when making contracting decisions, employers should take into account that workers are heterogenous with respect to both their productivity and their social preferences. This paper presents causal evidence that they do. In a real-effort experiment, we elicit measures of workers' productivity and trustworthiness and make this information available to potential employers. Our data show that employers pay significant wage premia for both traits. Firms make highest profits with trustworthy workers, in particular with highly productive and trustworthy workers. We also document differences in the strength of gift exchange across worker types. In particular, output and profit levels of trustworthy workers are less dispersed than those of not-trustworthy workers
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