A model for orientation effects in electron‐transfer reactions

A method for solving the single‐particle Schrödinger equation with an oblate spheroidal potential of finite depth is presented. The wave functions are then used to calculate the matrix element T_BA which appears in theories of nonadiabatic electron transfer. The results illustrate the effects of mutual orientation and separation of the two centers on TBA. Trends in these results are discussed in terms of geometrical and nodal structure effects. Analytical expressions related to T_BA for states of spherical wells are presented and used to analyze the nodal structure effects for T_BA for the spheroidal wells

PLANNING AMBULANCE SERVICES FOR A RURAL EMERGENCY MEDICAL SERVICE DISTRICT

Public Economics,

Real-time determination of laser beam quality by modal decomposition

We present a real-time method to determine the beam propagation ratio M2 of laser beams. The all-optical measurement of modal amplitudes yields M2 parameters conform to the ISO standard method. The experimental technique is simple and fast, which allows to investigate laser beams under conditions inaccessible to other methods.Comment: 8 pages, 4 figures, published in Optics Expres

Biplane Fluoroscopy for Hindfoot Motion Analysis during Gait: A Model-based Evaluation

The purpose of this study was to quantify the accuracy and precision of a biplane fluoroscopy system for model-based tracking of in vivo hindfoot motion during over-ground gait. Gait was simulated by manually manipulating a cadaver foot specimen through a biplane fluoroscopy system attached to a walkway. Three 1.6-mm diameter steel beads were implanted into the specimen to provide marker-based tracking measurements for comparison to model-based tracking. A CT scan was acquired to define a gold standard of implanted bead positions and to create 3D models for model-based tracking. Static and dynamic trials manipulating the specimen through the capture volume were performed. Marker-based tracking error was calculated relative to the gold standard implanted bead positions. The bias, precision, and root-mean-squared (RMS) error of model-based tracking was calculated relative to the marker-based measurements. The overall RMS error of the model-based tracking method averaged 0.43 ± 0.22 mm and 0.66 ± 0.43° for static and 0.59 ± 0.10 mm and 0.71 ± 0.12° for dynamic trials. The model-based tracking approach represents a non-invasive technique for accurately measuring dynamic hindfoot joint motion during in vivo, weight bearing conditions. The model-based tracking method is recommended for application on the basis of the study results

Quality management system in road construction

A presente comunicação apresenta e analisa os dados obtidos durante a fase de construção de uma Auto-Estrada em conformidade com um sistema de controlo de qualidade implementado de acordo com a ISO 9001:2000. Os dados experimentais resultam do controlo de compactação das diferentes camadas: aterro, leito do pavimento, sub-base. Estes dados são objecto de uma análise estatística com fins múltiplos, a saber: 1. conhecer as dispersão dos resultados por camada, com verificação da lei de distribuição normal e da probabilidade de ocorrência dos valores dentro da gama requerida no controlo de qualidade; 2. utilização do teste t-Student com o fim de testar a validade do controlo do Gestor da obra face ao controlo do Construtor. A análise estatística feita permite dispor de dados estatísticos que asseguram uma maior segurança na validação dos resultados dos ensaios do controlo de compactação e conhecer mais rigorosamente a qualidade global do trabalho realizado.This paper presents and analyzes data collected during a motorway construction in conformity with a quality control system developed according to the ISO 9001:2000 Standard. These data were obtained from results of “in situ” tests carried out during the compaction control of the different layers: embankment, capping layer and sub-base. Statistical analysis of these data is done with multiple purposes: 1. To know the scattering of control parameters in each layer, verifying at the same time the normal distribution law and the probability of occurrence of values outside the required specification; 2. Use of the t-Student test in order to evaluate the validity of the control made by the Enterprise Manager in relation to the constructor’s. This statistical analysis gives information that ensures a safer validation of control compaction results and a more accurate way to evaluate the global quality of the works.Sociedade Portuguesa de GeotecniaAssociação Brasileira de Mecânica dos Solos e Engenharia GeotécnicaUniversidade de Aveiro. Secção Autónoma de Engenharia Civi

Bose-Einstein condensation of chromium

We report on the generation of a Bose-Einstein condensate in a gas of chromium atoms, which will make studies of the effects of anisotropic long-range interactions in degenerate quantum gases possible. The preparation of the chromium condensate requires novel cooling strategies that are adapted to its special electronic and magnetic properties. The final step to reach quantum degeneracy is forced evaporative cooling of 52Cr atoms within a crossed optical dipole trap. At a critical temperature of T~700nK, we observe Bose-Einstein condensation by the appearance of a two-component velocity distribution. Released from an anisotropic trap, the condensate expands with an inversion of the aspect ratio. We observe critical behavior of the condensate fraction as a function of temperature and more than 50,000 condensed 52Cr atoms.Comment: 4 pages, 4 figure

Problems and Current Trends in Rock Magnetism and Paleomagnetism

Continental drift, seafloor spreading, plate tectonics: These terms conjure up a picture of the whole of Earth\u27s lithospheric plates in motion, a picture that truly represents a revolution in the earth sciences that took place in the 1960s and permanently changed our view of a more static world. If someone were to ask which subdiscipline of the geosciences has provided the crucial quantitative evidence about the past locations of discrete parts of continental and oceanic plates, the answer would be geomagnetism and paleomagnetism. Polarity stratigraphy, based on radiometrically dated 180° reversals of the dipolar geomagnetic field, informs us about the locations of parts of the seafloor in the past, and paleomagnetically determined paleolatitudes of continental rocks provide similar information about past locations of continental plates

Evaluation of Chlorosulfonyl Pyridine for Protecting Wood from Soft-Rot Fungi Using A Tensile Strength Test

Laboratory evaluation of a promising new wood preservative, 2,3,5,6,-tetrachloro-4 methylsulfonyl pyridine, was conducted to determine its relative effectiveness against two soft-rot fungi using tensile strength as the measure of the protection value. One-sixteenth-inch sapwood specimens of three species: ponderosa pine (Pinus ponderosa Laws.), sweetgum (Liquidambar styraciflua L.), and pondcypress (Taxodium ascendens Bong.); were treated with various levels of preservative and exposed to Graphium sp. and Acremonium sp. in test tube incubation chambers for 14 days. Statistical comparison of strength values of treated sweetgum specimens exposed to Graphium sp. indicated no significant difference between the protective properties of chlorosulfonyl pyridine and pentachlorophenol. Multiple comparisons of the untreated unincubated specimen mean with treated specimen means, however, indicated that 0.05 pcf of chlorosulfonyl pyridine was required to provide the same protection as afforded by 0.03 pcf of pentachlorophenol. Results also revealed that Graphium sp. had a relatively high wood-deterioration capacity