A study on the intensive use of air conditioning in large retail stores

In addition to an increase in greenhouse effect emissions the intensive use of air conditioning in the retail sector can eventually carry implications on the health of some of those directly exposed to sudden cooling particularly in hot summer days. This paper reports the results of an experimental study conducted in the summer of 2005 in the United Kingdom investigating air conditioning frequency of use and the indoor air temperatures of air conditioned premises. It was found that in some large retail stores indoor air temperatures could be set higher improving thermal comfort and contributing towards the environment

Elastic Stress Ratchetting and Corotational Stress Rates

It is well accepted that stresses should return to their original state after a closed elastic strain cycle. Here, we consider originally unstressed elements undergoing such cycles. We presume isotropic materials and use Truesdell’s hypoelastic law. Depending on the applied corotational stress rate, undesirable stress ratchetting is observed in case of two commonly used objective rates, namely the Zaremba-Jaumann and the Green/Naghdi rates. The strain cycle reaches its original stress-free state when the logarithmic rate is applied

A Closed-form Solution to Finite Bending of a Compressible Elastic-perfectly Plastic Rectangular Block

The self-consistent Eulerian rate-type elastoplastic model based on the logarithmic rate is used to study finite bending of a compressible elastic-perfectly plastic rectangular block. It is found that an explicit closed-form solution for this typical inhomogeneous finite deformation , mode may be available in a general case of compressible deformation with a stretch normal to the bending plane, where the maximum circumferential stretch at the outer surface serves as an Independent parameter. Expressions are given for the bending angle, the bending moment, the the outer and the inner radii, and the radii of the two moving elastic-plastic interfaces, etc. The exact stress distribution on any circumferential cross-section of the deformed block is accordingly determined

Finite Eulerian Elastoplasticity without Strain

In the last few decades a number of phenomenological models have been developed fordescribing elastoplastic materials undergoing finite deformations. They are different in structure,e.g., their formulation is related to the reference or to the actual configuration , i.e., it is a Lagrangeanor Eulerian formulation or it may contain elastic and/or plastic deformations. This study hasshown that the most simple and straightforward obtained constitutive relation is free from anynotion of elastic or plastic deformation. Moreover, it is related to the actual configuration, andthus omits to the greatest possible extent, quantities containing unwanted geometric deformationinformations

Absolute energy-resolved measurements of the H-+H→H2+e- associative detachment reaction using a merged-beam apparatus

Using a merged-beam configuration, we have performed absolute measurements for the associative detachment reaction H-+H→H2+e-. Our energy-resolved measurements for this process remove a long-standing discrepancy between theory and experiment for this fundamental reaction. In particular, we find excellent agreement with theoretical results which previously seemed to be ruled out by earlier experiments performed using a flowing afterglow technique

Generation of neutral atomic beams utilizing photodetachment by high power diode laser stacks

We demonstrate the use of high power diode laser stacks to photodetach fast hydrogen and carbon anions and produce ground term neutral atomic beams. We achieve photodetachment efficiencies of $\sim$7.4\% for H$^-$ at a beam energy of 10\,keV and $\sim$3.7\% for C$^-$ at 28\,keV. The diode laser systems used here operate at 975\,nm and 808\,nm, respectively, and provide high continuous power levels of up to 2\,kW, without the need of additional enhancements like optical cavities. The alignment of the beams is straightforward and operation at constant power levels is very stable, while maintenance is minimal. We present a dedicated photodetachment setup that is suitable to efficiently neutralize the majority of stable negative ions in the periodic table

Low-energy charge transfer for collisions of Si3+ with atomic hydrogen

Cross sections of charge transfer for Si3+ ions with atomic hydrogen at collision energies of ≈40–2500 eV/u were carried out using a merged-beam technique at the Multicharged Ion Research Facility at Oak Ridge National Laboratory. The data span an energy range in which both molecular orbital close coupling (MOCC) and classical trajectory Monte Carlo (CTMC) calculations are available. The influence of quantum mechanical effects of the ionic core as predicted by MOCC is clearly seen in our results. However, discrepancies between our experiment and MOCC results toward higher collision energies are observed. At energies above 1000 eV/u good agreement is found with CTMC results

A simple double-focusing electrostatic ion beam deflector

We have developed an electrostatic, double-focusing 90° deflector for fast ion beams consisting of concentric cylindrical plates of differing heights. In contrast to standard cylindrical deflectors, our design allows for focusing of an incoming parallel beam not only in the plane of deflection but also in the orthogonal direction. The optical properties of our design resemble those of a spherical capacitor deflector while it is much easier and more cost effective to manufacture

Associative detachment of H− + H → H2 + e−

Using a merged-beams apparatus, we have measured the associative detachment (AD) reaction of H−+H→H2+e− for relative collision energies up to Er≤4.83 eV. These data extend above the 1-eV limit of our earlier results. We have also updated our previous theoretical work to account for AD via the repulsive 2Σg+ H2− potential energy surface and for the effects at Er≥0.76 eV on the experimental results due to the formation of long-lived H2 resonances lying above the H+H separated atoms limit. Merging both experimental data sets, our results are in good agreement with our new theoretical calculations and confirm the prediction that this reaction essentially turns off for Er≳2 eV. Similar behavior has been predicted for the formation of protonium from collisions of antiprotons and hydrogen atoms