3,407 research outputs found

    Metallurgical Applications of Polarized Light

    Get PDF
    Very little has been written concerning the theory of the metallurgical polarization microscope. Records of metallurgical studies utilizing this instrument are widely scattered among the literature, and are mostly material of an uncoordinated and irrelevant nature. It is the feeling of the author that a coordinated investigation of the metallurgical applications of polarized light will yield results providing the metallurgist with another means for the study of metals and their properties

    The Age-Specific Force of Natural Selection and Walls of Death

    Full text link
    W. D. Hamilton's celebrated formula for the age-specific force of natural selection furnishes predictions for senescent mortality due to mutation accumulation, at the price of reliance on a linear approximation. Applying to Hamilton's setting the full non-linear demographic model for mutation accumulation of Evans et al. (2007), we find surprising differences. Non-linear interactions cause the collapse of Hamilton-style predictions in the most commonly studied case, refine predictions in other cases, and allow Walls of Death at ages before the end of reproduction. Haldane's Principle for genetic load has an exact but unfamiliar generalization.Comment: 27 page

    High Temperature Laser Sintering: An investigation into mechanical properties and shrinkage characteristics of Poly (Ether Ketone) structures

    Get PDF
    Copyright © 2014 Elsevier. NOTICE: this is the author’s version of a work that was accepted for publication in Materials and Design. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Materials and Design, Vol. 61 (2014). DOI: 10.1016/j.matdes.2014.04.035This paper presents an investigation into the properties of Poly Ether Ketone (PEK) components using the commercial high temperature laser sintering system, EOSINT P800. The shrinkage and the mechanical performance of components across the entire build chamber have been tested and a non-linear shrinkage profile has been obtained. The middle of the build chamber recorded the highest degree of shrinkage and the shrinkage in Z direction had the largest variation. The laser sintered components built in X and Y directions recorded a 10% lower tensile strength than the injection moulded samples of the same material where those built in the Z direction showed an approximately 50% decrease in strength in comparison with the injection moulded test specimens. The crystallinity between the skin and the core of the sintered samples was different; varied with the position within the build chamber and coincided with noticeable sample colour changes

    Control Systems’ Effect on Attributional Processes and Sales Outcomes: A Cybernetic Information-Processing Perspective

    Get PDF
    Built upon a cybernetic information-processing framework, this article advances and empirically tests a conceptual model proposing the relationships between sales controls (outcome, activity, capability), salespeople’s attributional ascriptions (effort, strategy, ability), attributional dimensions (internal/external, stable/unstable), and psychological consequences (job satisfaction, performance expectation). The study challenges the assumption in the sales literature that attributional dimensions cleanly map onto attributional ascriptions. Findings support that sales control systems affect salespeople’s attribution processes in ways suggesting that the processes are more malleable than heretofore theorized in the marketing literature. Furthermore, the study demonstrates that control systems differentially affect attribution processes across two cultures: the United States and China. The article concludes with a discussion of research and managerial implications.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

    High Mass Triple Systems: The Classical Cepheid Y Car

    Full text link
    We have obtained an HST STIS ultraviolet high dispersion Echelle mode spectrum the binary companion of the double mode classical Cepheid Y Car. The velocity measured for the hot companion from this spectrum is very different from reasonable predictions for binary motion, implying that the companion is itself a short period binary. The measured velocity changed by 7 km/ s during the 4 days between two segments of the observation confirming this interpretation. We summarize "binary" Cepheids which are in fact members of triple system and find at least 44% are triples. The summary of information on Cepheids with orbits makes it likely that the fraction is under-estimated.Comment: accepted by A
    • …
    corecore