Numerical study of radiative corrections in the low Q2Q^2 region at HERA

A detailed numerical study of radiative corrections in the low $Q^2$ region at the HERA $ep$ collider was performed. The specific case of the total photoproduction cross section measurement was taken as an example. Two different programs, TERAD91 and HERACLES4.2, were used to get an estimation of the size of radiative effects. It was found that radiative corrections can be quite large in some points of the space of leptonic $(x,y)$ variables. However, after imposing experimentally feasible cuts on the radiated photon and the hadronic final state one gets corrections at the level of a few per cent.Comment: 12 pages, 6 figures (not included), Deutsches Electronen Synchrotron preprint DESY 92-173, LaTex, hardcopy of the figures available upon request to [email protected]

Development of Heterogeneous Photosensitized Transition Metal Oxide Water-Splitting Catalysts on Silica Support

The research presented in this manuscript describes the development of photosensitized inexpensive catalysts based on readily available materials. The investigation covers synthesis and characterization of photosensitizers based on porphyrins, mechanical and thermal coating of solid support with semiconducting transition metal oxides, photosensitization of the semiconducting layer, and characterization of the photoelectrochemical properties displayed by the new materials. The process of water oxidation is of primary interest here, with little emphasis put on reduction of protons to gaseous hydrogen. Photoelectrochemically produced protons serve as a probe of effectiveness of the catalysts. Several systems are described, and two catalysts are identified as the most efficient

APPLICATION OF ALLOMETRY FOR DETERMINATION OF STRENGTH PROFILE IN YOUNG FEMALE ATHLETES FROM DIFFERENT SPORTS

The goal of the study was to determine a strength profile in young female athletes practising different sports and to use allometry to evaluate muscular strength with respect to body mass. The study included 42 women who practised taekwondo (n = 10), weightlifting (n = 10), canoeing (n = 14) and speed skating (n = 8). Measurements of maximal muscle torques under static conditions in 10 groups of flexors and extensors of the elbow, shoulder, hip, knee and trunk were carried out. The MANCOVA procedure was employed to compare means between the groups. A logarithm of body mass was adopted as a covariate. Relationships between body mass and muscle torques in each muscle group were determined using a procedure of linear regression. The analysis of residuals was employed for the evaluation of maximal muscle torques. Mean values of logarithms of maximal muscle torques were significantly different for the representatives of individual sports and they depended on the logarithm of body mass. It was proposed to use a mean of residuals normalized for individual muscle groups as a synthetic strength index (mean of the strength profile). The women practising canoeing were characterized by the highest strength index. Its lowest values were obtained by weightlifting and taekwondo athletes. Differences in strength profiles in the tested athletes were attributed to the specific nature of their sports. It is suggested to use an allometric relationship scaled by body mass for strength assessment

Longtime behavior of nonlocal Cahn-Hilliard equations

Here we consider the nonlocal Cahn-Hilliard equation with constant mobility in a bounded domain. We prove that the associated dynamical system has an exponential attractor, provided that the potential is regular. In order to do that a crucial step is showing the eventual boundedness of the order parameter uniformly with respect to the initial datum. This is obtained through an Alikakos-Moser type argument. We establish a similar result for the viscous nonlocal Cahn-Hilliard equation with singular (e.g., logarithmic) potential. In this case the validity of the so-called separation property is crucial. We also discuss the convergence of a solution to a single stationary state. The separation property in the nonviscous case is known to hold when the mobility degenerates at the pure phases in a proper way and the potential is of logarithmic type. Thus, the existence of an exponential attractor can be proven in this case as well

A Kohn-Sham system at zero temperature

An one-dimensional Kohn-Sham system for spin particles is considered which effectively describes semiconductor {nano}structures and which is investigated at zero temperature. We prove the existence of solutions and derive a priori estimates. For this purpose we find estimates for eigenvalues of the Schr\"odinger operator with effective Kohn-Sham potential and obtain $W^{1,2}$-bounds of the associated particle density operator. Afterwards, compactness and continuity results allow to apply Schauder's fixed point theorem. In case of vanishing exchange-correlation potential uniqueness is shown by monotonicity arguments. Finally, we investigate the behavior of the system if the temperature approaches zero.Comment: 27 page

What we learned from the Dust Bowl: lessons in science, policy, and adaptation

This article provides a review and synthesis of scholarly knowledge of Depression-era droughts on the North American Great Plains, a time and place known colloquially as the Dust Bowl era or the Dirty Thirties. Recent events, including the 2008 financial crisis, severe droughts in the US corn belt, and the release of a popular documentary film, have spawned a resurgence in public interest in the Dust Bowl. Events of the Dust Bowl era have also proven in recent years to be of considerable interest to scholars researching phenomena related to global environmental change, including atmospheric circulation, drought modeling, land management, institutional behavior, adaptation processes, and human migration. In this review, we draw out common themes in terms of not only what natural and social scientists have learned about the Dust Bowl era itself, but also how insights gained from the study of that period are helping to enhance our understanding of climate–human relations more generally

Changes in handgrip force and blood lactate as response to simulated climbing competition

The aim of the study was to estimate post-competition changes in handgrip strength and blood lactate in climbers and relationships of the studied variables with declared climbing ability of the tested athletes. Twenty one male climbers volunteered to take part in the experiment. Each subject took part in simulated lead climbing competition on the artificial wall – (difficulty 7a in French scale). The blood lactate concentration was measured pre-climbing and then 3 min and 30 min post-climbing. Grip force of both hands (dominant and non-dominant) was measured twice – pre-climbing and 1 min post-climbing (semi-final). Maximum heart rate during climbing reached 181.4±7.7 beats per minute. Lactate concentration amounted to 6.35±1.50 mmol/l and 2.28±0.66 mmol/l 3 min and 30 min post-climbing, respectively. Handgrip force related to body mass (averaged for both hands) decreased significantly from 7.39±1.30 N/kg pre-climbing to 6.57±1.05 N/kg 1 min post-climbing. Self reported climbing ability was correlated with lactate concentration and handgrip force, as well. It was demonstrated that athletes reporting higher climbing ability showed better lactate recovery

Bayesian accrual prediction for interim review of clinical studies: open source R package and smartphone application

Illustration of use of R accrual package. (DOCX 917 kb