26,392 research outputs found

    Strainrange partitioning behavior of an automotive turbine alloy

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    This report addresses Strainrange Partitioning, an advanced life prediction analysis procedure, as applied to CA-101 (cast IN 792 + Hf), an alloy proposed for turbine disks in automotive gas turbine engines. The methodology was successful in predicting specimen life under thermal-mechanical cycling, to within a factor of + or - 2

    Adiabatic and Non-Adiabatic Contributions to the Free Energy from the Electron-Phonon Interaction for Na, K, Al, and Pb

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    We calculate the adiabatic contributions to the free energy due to the electron--phonon interaction at intermediate temperatures, 0⩽kBT<ϵF0 \leqslant k_{B} T < \epsilon_{F} for the elemental metals Na, K, Al, and Pb. Using our previously published results for the nonadiabatic contributions we show that the adiabatic contribution, which is proportional to T2T^{2} at low temperatures and goes as T3T^{3} at high temperatures, dominates the nonadiabatic contribution for temperatures above a cross--over temperature, TcT_{c}, which is between 0.5 and 0.8 TmT_{m}, where TmT_{m} is the melting temperature of the metal. The nonadiabatic contribution falls as T−1T^{-1} for temperatures roughly above the average phonon frequency.Comment: Updated versio

    Did Neoliberalizing West African Forests Produce a New Niche for Ebola?

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    A recent study introduced a vaccine that controls Ebola Makona, the Zaire ebolavirus variant that has infected 28,000 people in West Africa. We propose that even such successful advances are insufficient for many emergent diseases. We review work hypothesizing that Makona, phenotypically similar to much smaller outbreaks, emerged out of shifts in land use brought about by neoliberal economics. The epidemiological consequences demand a new science that explicitly addresses the foundational processes underlying multispecies health, including the deep-time histories, cultural infrastructure, and global economic geographies driving disease emergence. The approach, for instance, reverses the standard public health practice of segregating emergency responses and the structural context from which outbreaks originate. In Ebola's case, regional neoliberalism may affix the stochastic "friction" of ecological relationships imposed by the forest across populations, which, when above a threshold, keeps the virus from lining up transmission above replacement. Export-led logging, mining, and intensive agriculture may depress such functional noise, permitting novel spillovers larger forces of infection. Mature outbreaks, meanwhile, can continue to circulate even in the face of efficient vaccines. More research on these integral explanations is required, but the narrow albeit welcome success of the vaccine may be used to limit support of such a program.SCOPUS: re.jinfo:eu-repo/semantics/publishe

    What is the excess risk of infertility in women after genital chlamydia infection? A systematic review of the evidence

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    Methods: Twelve databases were searched, limited to peer-reviewed literature published from January 1970 to September 2007. Conference abstracts and reference lists from reviews published since 2000 and from key articles were hand-searched. Studies were selected for review if they met the following criteria: (1) the study population comprised women of child-bearing age (defined as 15–45 years) and incorporated a comparison group of women documented as "chlamydia negative"; (2) the study outcomes included either infertility or successful pregnancy; and (3) the study design was one of the following: cohort, randomised controlled trial, "before and after" study, screening trial and systematic review. Studies were excluded if they described genital infections that either did not include Chlamydia trachomatis or described genital chlamydial co-infection, in which no data were available for C trachomatis infection alone. Results: 3349 studies were identified by the search. One study satisfied the inclusion criteria, a longitudinal investigation measuring pregnancy rates in adolescent women with and without current chlamydial infection at baseline. That study reported no significant difference in subsequent pregnancy rates; however, it had serious methodological limitations, which restricted its conclusions. Conclusions: This systematic review demonstrates the absence of valid evidence on the attributable risk of post-infective tubal factor infertility after genital chlamydial infection. The findings contribute empirical data to the growing debate surrounding previous assumptions about the natural history of chlamydial infection in women

    Fast track children's hearing pilot: final report of the evaluation of the pilot

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    This report presents key findings of the evaluation of the Fast Track children’s hearings pilot in Scotland1. The research was undertaken by staff at the Universities of Glasgow, Stirling and Strathclyde between February 2003 and January 2005

    Neutron and Proton Transverse Emission Ratio Measurements and the Density Dependence of the Asymmetry Term of the Nuclear Equation of State

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    Recent measurements of pre-equilibrium neutron and proton transverse emission from (112,124)Sn+(112,124)Sn reactions at 50 MeV/A have been completed at the National Superconducting Cyclotron Laboratory. Free nucleon transverse emission ratios are compared to those of A=3 mirror nuclei. Comparisons are made to BUU transport calculations and conclusions concerning the density dependence of the asymmetry term of the nuclear equation-of-state at sub-nuclear densities are made. The double-ratio of neutron-proton ratios between two reactions is employed as a means of reducing first-order Coulomb effects and detector efficiency effects. Comparison to BUU model predictions indicate a density dependence of the asymmetry energy that is closer to a form in which the asymmety energy increases as the square root of the density for the density region studied. A coalescent-invariant analysis is introduced as a means of reducing suggested difficulties with cluster emission in total nucleon emission. Future experimentation is presented

    Bone Quality and Quantity are Mediated by Mechanical Stimuli

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    Prevention of fracture through improved bone mechanical strength is of great importance given the large number of bone disease-related fractures each year, the decreased quality of life associated with fractures, and the large anticipated increase in fracture incidence over the upcoming years due to the aging population. Exercise and other forms of mechanical stimulation have been shown to increase bone mass, suggesting improved strength. However, while bone mass is a good indicator of strength, other components (such as bone quality) also contribute to bone mechanical integrity. While increased bone mass has been explored considerably using both exercise and targeted loading models, the role of mechanical stimulation in altering bone quality has been explored to a lesser degree. Understanding how to improve both the quantity and quality of bone is critical to increasing fracture resistance. Herein, we discuss quantity and quality-based improvements that have been observed using both exercise and targeted loading models of bone adaptation

    Tractable Combinations of Global Constraints

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    We study the complexity of constraint satisfaction problems involving global constraints, i.e., special-purpose constraints provided by a solver and represented implicitly by a parametrised algorithm. Such constraints are widely used; indeed, they are one of the key reasons for the success of constraint programming in solving real-world problems. Previous work has focused on the development of efficient propagators for individual constraints. In this paper, we identify a new tractable class of constraint problems involving global constraints of unbounded arity. To do so, we combine structural restrictions with the observation that some important types of global constraint do not distinguish between large classes of equivalent solutions.Comment: To appear in proceedings of CP'13, LNCS 8124. arXiv admin note: text overlap with arXiv:1307.179

    Machinery Costs -- Own, Lease or Custom Hire

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    This publication examines the costs and considerations for machine ownership versus leasing or custom hiring. Total costs associated with farm machinery have increased as farm operators have expanded their operations and substituted machines for labor. Corresponding increases in productivity per worker, average farm size, and total machinery have been at the expense of operating capitol
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