978 research outputs found

    Electrodeposition from supercritical fluids

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    Recent studies have shown that it is possible to electrodeposit a range of materials, such as Cu, Ag and Ge, from various supercritical fluids, including hydrofluorocarbons and mixtures of CO2 with suitable co-solvents. In this perspective we discuss the relatively new field of electrodeposition from supercritical fluids. The perspective focuses on some of the underlying physical chemistry and covers both practical and scientific aspects of electrodeposition from supercritical fluids. We also discuss possible applications for supercritical fluid electrodeposition and suggest some key developments that are required to take the field to the next stage

    An empirical analysis of the cost of rearing dairy heifers from birth to first calving and the time taken to repay these costs

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    Rearing quality dairy heifers is essential to maintain herds by replacing culled cows. Information on the key factors influencing the cost of rearing under different management systems is, however, limited and many farmers are unaware of their true costs. This study determined the cost of rearing heifers from birth to first calving in Great Britain including the cost of mortality, investigated the main factors influencing these costs across differing farming systems and estimated how long it took heifers to repay the cost of rearing on individual farms. Primary data on heifer management from birth to calving was collected through a survey of 101 dairy farms during 2013. Univariate followed by multivariable linear regression was used to analyse the influence of farm factors and key rearing events on costs. An Excel spreadsheet model was developed to determine the time it took for heifers to repay the rearing cost. The mean +/- SD ages at weaning, conception and calving were 62 +/- 13, 509 +/- 60 and 784 +/- 60 days. The mean total cost of rearing was 1819 pound +/- 387/heifer with a mean daily cost of 2.31 pound +/- 0.41. This included the opportunity cost of the heifer and the mean cost of mortality, which ranged from 103.49 pound to 146.19 pound/surviving heifer. The multivariable model predicted an increase in mean cost of rearing of 2.87 pound for each extra day of age at first calving and a decrease in mean cost of 6.06 pound for each percentile increase in time spent at grass. The model also predicted a decrease in the mean cost of rearing in autumn and spring calving herds of 273.20 pound and 288.56 pound, respectively, compared with that in all-year-round calving herds. Farms with herd sizes100 had lower mean costs of between 301.75 pound and 407.83 pound compared with farms with <100 milking cows. The mean gross margin per heifer was 441.66 pound +/- 304.56 (range 367.63 pound to 1120.08) pound, with 11 farms experiencing negative gross margins. Most farms repaid the cost of heifer rearing in the first two lactations (range 1 to 6 lactations) with a mean time from first calving until breaking even of 530 +/- 293 days. The results of the economic analysis suggest that management decisions on key reproduction events and grazing policy significantly influence the cost of rearing and the time it takes for heifers to start making a profit for the farm

    Far-infrared transmission studies of c-axis oriented superconducting MgB2 thin film

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    We reported far-infrared transmission measurements on a c-axis oriented superconducting MgB2_{2} thin film in the frequency range of 30 \sim 250 cm1^{-1}. We found that these measurements were sensitive to values of scattering rate 1/τ1/\tau and superconducting gap 2Δ2\Delta. By fitting the experimental transmission spectra at 40 K and below, we obtained 1/τ=1/\tau = (700 \sim 1000) cm1^{-1} and 2Δ(0)2\Delta (0)\cong 42 cm1^{-1}. These two quantities suggested that MgB2_{2} belong to the dirty limit.Comment: submitted at May

    Interjoint Coordination in Kicking a Moving Target: A Comparison Between Elite and Nonelite Taekwondo Players.

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    Patterns of interjoint coordination in the kicking legs of taekwondo players were investigated to understand movement pattern variability as a functional property of skill level. Elite and nonelite players performed roundhouse kicks against a custom-built moving target fitted with an accelerometer, and movements were recorded by motion capture. Average foot segment velocities of 13.6 and 11.4 m/s were recorded for elite and nonelite players, respectively (P < .05), corresponding to target accelerations of 87.5 and 70.8g (P < .05). Gradient values derived from piecewise linear regression of continuous relative phase curves established the comparative incoordination of nonelite taekwondo players in the form of an overshoot behavior during the crucial period leading to target impact (P < .05). This overshoot was apparent in both knee-hip and ankle-knee continuous relative phase curves. Elite players generated greater limb speed and impact force through more effective limb segment coordination. The combination of continuous relative phase and piecewise linear regression techniques allowed identification of alternate joint control approaches in the 2 groups

    A benefit–cost analysis of different response scenarios to COVID ‐19: A case study

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    Background This paper compares the direct benefits to the State of Western Australia from employing a “suppression” policy response to the COVID-19 pandemic rather than a “herd immunity” approach. Methods An S-I-R (susceptible-infectious-resolved) model is used to estimate the likely benefits of a suppression COVID-19 response compared to a herd immunity alternative. Direct impacts of the virus are calculated on the basis of sick leave, hospitalizations, and fatalities, while indirect impacts related to response actions are excluded. Results Preliminary modeling indicates that approximately 1700 vulnerable person deaths are likely to have been prevented over 1 year from adopting a suppression response rather than a herd immunity response, and approximately 4500 hospitalizations. These benefits are valued at around AUD4.7 billion. If a do nothing policy had been adopted, the number of people in need of hospitalization is likely to have overwhelmed the hospital system within 50 days of the virus being introduced. Maximum hospital capacity is unlikely to be reached in either a suppression policy or a herd immunity policy. Conclusion Using early international estimates to represent the negative impact each type of policy response is likely to have on gross state product, results suggest the benefit–cost ratio for the suppression policy is slightly higher than that of the herd immunity policy, but both benefit–cost ratios are less than one

    Spinodal Decomposition in a Binary Polymer Mixture: Dynamic Self Consistent Field Theory and Monte Carlo Simulations

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    We investigate how the dynamics of a single chain influences the kinetics of early stage phase separation in a symmetric binary polymer mixture. We consider quenches from the disordered phase into the region of spinodal instability. On a mean field level we approach this problem with two methods: a dynamical extension of the self consistent field theory for Gaussian chains, with the density variables evolving in time, and the method of the external potential dynamics where the effective external fields are propagated in time. Different wave vector dependencies of the kinetic coefficient are taken into account. These early stages of spinodal decomposition are also studied through Monte Carlo simulations employing the bond fluctuation model that maps the chains -- in our case with 64 effective segments -- on a coarse grained lattice. The results obtained through self consistent field calculations and Monte Carlo simulations can be compared because the time, length, and temperature scales are mapped onto each other through the diffusion constant, the chain extension, and the energy of mixing. The quantitative comparison of the relaxation rate of the global structure factor shows that a kinetic coefficient according to the Rouse model gives a much better agreement than a local, i.e. wave vector independent, kinetic factor. Including fluctuations in the self consistent field calculations leads to a shorter time span of spinodal behaviour and a reduction of the relaxation rate for smaller wave vectors and prevents the relaxation rate from becoming negative for larger values of the wave vector. This is also in agreement with the simulation results.Comment: Phys.Rev.E in prin

    Cigarette smoking and adenocarcinomas of the esophagus and esophagogastric junction: a pooled analysis from the International BEACON Consortium

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    BackgroundPrevious studies that showed an association between smoking and adenocarcinomas of the esophagus and esophagogastric junction were limited in their ability to assess differences by tumor site, sex, dose–response, and duration of cigarette smoking cessation.MethodsWe used primary data from 10 population-based case–control studies and two cohort studies from the Barrett’s Esophagus and Esophageal Adenocarcinoma Consortium. Analyses were restricted to white non-Hispanic men and women. Patients were classified as having esophageal adenocarcinoma (n = 1540), esophagogastric junctional adenocarcinoma (n = 1450), or a combination of both (all adenocarcinoma; n = 2990). Control subjects (n = 9453) were population based. Associations between pack-years of cigarette smoking and risks of adenocarcinomas were assessed, as well as their potential modification by sex and duration of smoking cessation. Study-specific odds ratios (ORs) estimated using multivariable logistic regression models, adjusted for age, sex, body mass index, education, and gastroesophageal reflux, were pooled using a meta-analytic methodology to generate summary odds ratios. All statistical tests were two-sided.ResultsThe summary odds ratios demonstrated strong associations between cigarette smoking and esophageal adenocarcinoma (OR = 1.96, 95% confidence interval [CI] = 1.64 to 2.34), esophagogastric junctional adenocarcinoma (OR = 2.18, 95% CI = 1.84 to 2.58), and all adenocarcinoma (OR = 2.08, 95% CI = 1.83 to 2.37). In addition, there was a strong dose–response association between pack-years of cigarette smoking and each outcome ( P &lt; .001). Compared with current smokers, longer smoking cessation was associated with a decreased risk of all adenocarcinoma after adjusting for pack-years (&lt;10 years of smoking cessation: OR = 0.82, 95% CI = 0.60 to 1.13; and ≥10 years of smoking cessation: OR = 0.71, 95% CI = 0.56 to 0.89). Sex-specific summary odds ratios were similar.ConclusionsCigarette smoking is associated with increased risks of adenocarcinomas of the esophagus and esophagogastric junction in white men and women; compared with current smoking, smoking cessation was associated with reduced risks.<br/

    Primordialists and Constructionists: a typology of theories of religion

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    This article adopts categories from nationalism theory to classify theories of religion. Primordialist explanations are grounded in evolutionary psychology and emphasize the innate human demand for religion. Primordialists predict that religion does not decline in the modern era but will endure in perpetuity. Constructionist theories argue that religious demand is a human construct. Modernity initially energizes religion, but subsequently undermines it. Unpacking these ideal types is necessary in order to describe actual theorists of religion. Three distinctions within primordialism and constructionism are relevant. Namely those distinguishing: a) materialist from symbolist forms of constructionism; b) theories of origins from those pertaining to the reproduction of religion; and c) within reproduction, between theories of religious persistence and secularization. This typology helps to make sense of theories of religion by classifying them on the basis of their causal mechanisms, chronology and effects. In so doing, it opens up new sightlines for theory and research

    Avaliação da Vergonha em Adolescentes: ‘The Other as Shamer Scale’

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    Shame, as a self-conscious, multidimensional and socially focused emotion, plays a central role in the mental health of individuals. In adolescents, shame is also a frequent experience and its assessment is important for research and clinical practice. This study aims to validate a brief measure of external shame (Other as Shamer Scale – brief version for adolescents: (OASB-A). The participants were 834 adolescents with a mean age of 15 years. The final model of the OASB-A (8 items), obtained through CFA, presents a good fit to the data. The OASB-A shows a good internal consistency and an adequate temporal reliability. The OASB-A also reveals significant correlations with traumatic shame experiences (IES-R) and psychopathological symptoms (DASS-21). The OASB-A is an economic and reliable measure to assess external shame in adolescents

    Measurement of the Charged Multiplicities in b, c and Light Quark Events from Z0 Decays

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    Average charged multiplicities have been measured separately in bb, cc and light quark (u,d,su,d,s) events from Z0Z^0 decays measured in the SLD experiment. Impact parameters of charged tracks were used to select enriched samples of bb and light quark events, and reconstructed charmed mesons were used to select cc quark events. We measured the charged multiplicities: nˉuds=20.21±0.10(stat.)±0.22(syst.)\bar{n}_{uds} = 20.21 \pm 0.10 (\rm{stat.})\pm 0.22(\rm{syst.}), nˉc=21.28±0.46(stat.)0.36+0.41(syst.)\bar{n}_{c} = 21.28 \pm 0.46(\rm{stat.}) ^{+0.41}_{-0.36}(\rm{syst.}) nˉb=23.14±0.10(stat.)0.37+0.38(syst.)\bar{n}_{b} = 23.14 \pm 0.10(\rm{stat.}) ^{+0.38}_{-0.37}(\rm{syst.}), from which we derived the differences between the total average charged multiplicities of cc or bb quark events and light quark events: Δnˉc=1.07±0.47(stat.)0.30+0.36(syst.)\Delta \bar{n}_c = 1.07 \pm 0.47(\rm{stat.})^{+0.36}_{-0.30}(\rm{syst.}) and Δnˉb=2.93±0.14(stat.)0.29+0.30(syst.)\Delta \bar{n}_b = 2.93 \pm 0.14(\rm{stat.})^{+0.30}_{-0.29}(\rm{syst.}). We compared these measurements with those at lower center-of-mass energies and with perturbative QCD predictions. These combined results are in agreement with the QCD expectations and disfavor the hypothesis of flavor-independent fragmentation.Comment: 19 pages LaTex, 4 EPS figures, to appear in Physics Letters
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