Numerical analysis of the influence of convection on off-eutectic solidification

Convection during solidification is predicted to lead to transverse inhomogeneities. With an off-eutectic melt a portion of the cross section should be single phase, and a portion of the two phase material will have a varying average composition and microstructure. This effect will be more pronounced at higher convection levels, lower freezing rates, and greater departures from the eutectic composition. During the performance of this research he was a graduate student at Clarkson College of Technology in Potsdam, NY.     

Impedance calculation of a single-layer air-core coil by means of resonant modal theory

A method for calculating the impedance of a single-layer air-core coil is developed. The coil is expressed by a pair of multiphase distributed-parameter lines. The nodal voltages within the coil are transformed into a modal domain by applying an eigen theory. The transformation diagonalises the nodal equation expressed by Y-parameters of the distributed-parameter lines. The method permits composition of an equivalent circuit of the air-core coil. The accuracy of the model is easily tuned by adjusting the number of eigenvalues taken into account. The choice of the eigenvalues is carried out by the voltage distribution along the wire of the coil. The dominant mode is obtained by an assumption that the voltage distribution is uniform. This mode gives the lowest antiresonant frequency of the coil. The other distribution patterns are assumed to be sinusoidal. The second dominant mode corresponds to the lowest space frequency among the distribution patterns. In general, there is no relation between the order of the calculated eigenvectors and the voltage distribution. Its order is sorted according to the voltage distribution using an initial eigenvector matrix. The accuracy of the impedance increases with the number of eigenvalues, which are taken into account according to the sorted order. A simplified lumped-parameter equivalent circuit of the coil is derived for the major modes. The simplified model is able to represent not only antiresonances but also resonances of an air-core coil. The accuracy of the proposed model is confirmed by comparisons with measured and theoretical results.     

地化录井产能预测方法

油层产能的确定，目前主要依赖于试油、地层测试及试采等方法。随着录井技术从定性到定量的发展，地化录井产能预测方法解决了随钻预测产能的问题。文中介绍了地球化学录井技术原理，阐明了产能控制因素与地化录井参数的关系，建立了产能预测方程。地化产能预测是一种技术和经济可行的随钻实时求产方法，对获取单层、特别是薄层产能参数具有重要的意义。它是对目前求方法的必要补充，在实际应用中见到了良好的地质效果。     

Genetic effects on dairy calf growth

Objectives were to establish growth patterns for weight and height in dairy calves from birth to 90 d and to estimate appropriate genetic parameters. Measurements were 7943 body weights and 7005 wither heights of 752 calves. Represented over 12 yr were three breeds, 348 dams, and 115 sires; data resulted from designed calf nutrition experiments. Sources of variation considered in various least squares analyses of variance were breed, sire in breed, calf in sire in breed, sex of calf, treatment-year category, and several interactions. Repeatabilities of weights and heights between birth and 90 d were .64 and .88; heritabilities were .22 and .30; genetic and phenotypic correlations were .53 and .73. A regression equation was estimated for each calf. From these 752 equations, heritabilities of initial weight, initial height, and rates of growth in weight and height were .53, .50, .44, and .19. Genetic correlations were .81; -.07; -.05; .26; .14; .84. Selection schemes for these traits in dairy cattle should consider that although weights and heights at birth and thereafter are highly and positively correlated genetically, as are gains, birth measurements and gains to 90 d may be uncorrelated.     

The Women's Health Curriculum by a problem-based learning method for medical students at the University of California, San Francisco

OBJECTIVES: Our objectives were to (1) expand and strengthen the women's health curriculum at the University of California, San Francisco, and (2) evaluate the responses of both medical students and faculty to this curriculum. STUDY DESIGN: A written evaluation of the curriculum in women's health was completed by both students and faculty. Variables studied included mean scores of cases, the overall course score, and the preferences of medical students for faculty specialty in teaching the small groups. RESULTS: The overall course evaluation score was 7.81 (range 1 to 10). For those students who had both faculty from internal medicine or family medicine and obstetrics and gynecology, there was a strong preference that obstetrician-gynecologists teach the majority of the cases. CONCLUSIONS: The new case-based curriculum in women's health was enthusiastically received by both medical students and faculty.     

Hydroxyapatite bone substitutes developed via replication of natural marine sponges

The application of synthetic cancellous bone has been shown to be highly successful when its architecture mimics that of the naturally interconnected trabeculae bone it aims to replace. The following investigation demonstrates the potential use of marine sponges as precursors in the production of ceramic based tissue engineered bone scaffolds. Three species of natural sponge, Dalmata Fina (Spongia officinalis Linnaeus, Adriatic Sea), Fina Silk (Spongia zimocca, Mediterranean) and Elephant Ear (Spongia agaricina, Caribbean) were selected for replication. A high solid content (80 %wt), low viscosity (126 mPas) hydroxyapatite slurry was developed, infiltrated into each sponge species and subsequently sintered, producing a scaffold structure that replicated pore architecture and interconnectivity of the precursor sponge. The most promising of the ceramic tissue engineered bone scaffolds developed, Spongia agaricina replicas, demonstrated an overall porosity of 56–61% with 83% of the pores ranging between 100 and 500 μm (average pore size 349 μm) and an interconnectivity of 99.92%.     

Forecasting solar radiation – Preliminary evaluation of an approach based upon the national forecast database

Our objective is to develop, and undertake a preliminary evaluation of a simple solar radiation forecast model using sky cover predictions from the National Digital Forecast Database as an input. This report describes the model and presents a limited evaluation of its performance against ground-measured and satellite-derived irradiances in Albany, New York.     

CO2 adsorption on carbon models of organic constituents of gas shale and coal

Imperfections of the organic matrix in coal and gas shales are modeled using defective and defect-free graphene surfaces to represent the structural heterogeneity and related chemical nature of these complex systems. Based upon previous experimental investigations that have validated the stability and existence of defect sites in graphene, plane-wave electronic density functional theory (DFT) calculations have been performed to investigate the mechanisms of CO(2) adsorption. The interactions of CO(2) with different surfaces have been compared, and the physisorption energy of CO(2) on the defective graphene adsorption site with one carbon atom missing (monovacancy) is approximately 4 times as strong as that on a perfect defect-free graphene surface, specifically, with a physisorption energy of ～210 meV on the monovacancy site compared to ～50 meV on a perfect graphene surface. The energy associated with the chemisorption of CO(2) on the monovacancy site is substantially stronger at ～1.72 eV. Bader charge, density of states, and vibrational frequency estimations were also carried out and the results indicate that the CO(2) molecule binds to the surface becoming more stable upon physisorption onto the monovacancy site followed by the original C═O bonds weakening upon CO(2) chemisorption onto the vacancy site.     

Multisensory exploration and object individuation in infancy.

Recent research indicates that by 4.5 months, infants use shape and size information as the basis for individuating objects but that it is not until 11.5 months that they use color information for this purpose. The present experiments investigated the extent to which infants' sensitivity to color information could be increased through select experiences. Five experiments were conducted with 10.5- and 9.5-month-olds. The results revealed that multimodal (visual and tactile), but not unimodal (visual only), exploration of the objects prior to the individuation task increased 10.5-month-olds' sensitivity to color differences. These results suggest that multisensory experience with objects facilitates infants' use of color information when individuating objects. In contrast, 9.5-month-olds did not benefit from the multisensory procedure; possible explanations for this finding are explored. Together, these results reveal how an everyday experience--combined visual and tactile exploration of objects--can promote infants' use of color information as the basis for individuating objects. More broadly, these results shed light on the nature of infants' object representations and the cognitive mechanisms that support infants' changing sensitivity to color differences. (PsycINFO Database Record (c) 2010 APA, all rights reserved)