Irregular, unknown light sources in dynamic global illumination

The goal in global illumination solutions for dynamic environments is to update a scene based on past scenes. For this difficult problem, current state of the art solutions are either not applicable, or unduly complex, when there are large changes in the illumination of unbounded number of objects. Such changes may be caused by the appearance of unexpected (at modeling time), irregular light sources.

We define a subset of dynamic environments in which new light sources may be user introduced, and implement solutions that complement existing schemes.     

Computation of feed-paths for casting solidification using level-set-method

The aim of the present work is to compute feed-paths and hot-spots by combining level-set-method based sharp interface and feed-path model. The model is based on the solution of energy and level-set equations in solid and liquid, with Stefan condition on the interface. The energy and level-set equation are discretized using finite-volume and finite-difference method, respectively. Feed-path is computed by tracking mass-less particles along the liquid-solid interface during solidification using combined Eulerian-Lagrangian framework. The proposed model is benchmarked on six test cases, where temperature contours and solidification time are compared with a finite-element-method based commercial software. The capability to predict the temporal evolution of interface and to identify multiple hot-spots is validated with an industrial aluminum-alloy lug casting. The numerical as well as experimental validations demonstrate the effectiveness of level-set-method for feed-path calculation.     

A COMPUTATIONAL MODEL OF COUPLED HEAT AND MOISTURE TRANSFER WITH PHASE CHANGEIN GRANULAR SUGAR DURING VARYING ENVIRONMENTAL CONDITIONS

As part of a comprehensive effort to predict the development of caking in granular materials, a mathematical model is introduced to model simultaneous heat and moisture transfer with phase change in porous media when undergoing temperature oscillations/cycling. The resulting model partial differential equations were solved using finite-volume procedures in the context of the PHYSICA framework and then applied to the analysis of sugar in storage. The influence of temperature on absorption/desorption and diffusion coefficients is coupled into the transport equations. The temperature profile, the depth of penetration of the temperature oscillation into the bulk solid, and the solids moisture content distribution were first calculated, and these proved to be in good agreement with experimental data. Then, the influence of temperature oscillation on absolute humidity, moisture concentration, and moisture migration for different parameters and boundary conditions was examined. As expected, the results show that moisture near boundary regions responds faster than farther away from them with surface temperature changes. The moisture absorption and desorption in materials occurs mainly near boundary regions (where interactions with the environment are more pronounced). Small amounts of solids moisture content, driven by both temperature and vapour concentration gradients, migrate between boundary and center with oscillating temperature.     

采用SC70封装的LED驱动器用单节锂离子电池驱动6个白光LED

引言 在蜂窝电话、PDA和便携式GPS等由电池供电的便携式产品中，高度集成的LT3491可为驱动背光照明电路组成简单和紧凑的解决方案。该器件具有内部补偿电路、LED开路保护功能、一个32V电源开关和一个32V肖特基二极管，而其封装却是纤巧的SC70。     

Gambling, health and age: Data from the National Epidemiologic Survey on Alcohol and Related Conditions.

The health effects of recreational gambling are presently unclear, particularly across age groups. Theories of healthy aging suggest that social activities, including gambling, may be beneficial to the health of older adults. Using cross-sectional data from the National Epidemiologic Survey on Alcohol and Related Conditions (N=43,093), the authors examined associations between gambling (categorized as nongambling, recreational gambling, or problem/pathological gambling) and health and functioning measures stratified by age (40-64 years and ≥65). Problem/pathological gambling was uniformly associated with poorer health measures among both younger and older adults. Among younger respondents, poorer health measures were also found among recreational gamblers. However, among older respondents, recreational gambling was associated not only with some negative measures (e.g., obesity) but also with some positive measures (e.g., better physical and mental functioning). Longitudinal studies are needed to clarify the relationship between gambling and health in older adults in the context of healthy aging. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Microalgae Chlorella as a potential bio-energy feedstock

Microalgae are promising biomass species owing to their fast growth rate and high CO₂ fixation ability as compared to terrestrial plants. Microalgae have long been recognized as potentially good source for biofuel production because of their high oil content and rapid biomass production. In this study Chlorella sp. MP-1 biomass was examined for its physical and chemical characteristics using Bomb calorimeter, TGDTA, CHN and FTIR. The proximate composition was calculated using standard ASTM methodology. Chlorella sp. MP-1 biomass shows low ash (5.93%), whereas high energy (18.59 MJ/kg), carbohydrate (19.46%), and lipid (28.82%) content. The algal de-oiled cake was characterized by FTIR spectroscopy and thermogravimetric study at 10 °C/min and 30 °C/min to investigate its feasibility for thermo-chemical conversion. The present investigation suggests that within the realm of biomass energy technologies the algal biomass can be used as feedstock for bio and thermo-chemical whereas the de-oiled cake for thermo-chemical conversion thereby serving the demand of second generation biofuels.     

Preferential biodegradation of structurally dissimilar dyes from a mixture by Brevibacillus laterosporus

Biodegradation of a mixture containing seven commercial textile dyes with different structures and color properties has been investigated by an ecofriendly strain--Brevibacillus laterosporus MTCC 2298. It showed 87% decolorization in terms of ADMI removal (American Dye Manufacturing Institute) within 24h. The effective decolorization of dye mixture was attained in the presence of metal salt--CaCl(2) and nitrogen sources. The induction of oxido-reductive enzymes such as veratryl alcohol oxidase, tyrosinase, NADH-DCIP reductase and azo reductase was found to be responsible for biotransformation of dyes. High performance thin layer chromatography exposed the mechanism of preferential biodegradation of dyes at different time periods. Significant change in the high pressure liquid chromatography and Fourier transform infrared spectroscopy of sample before and after treatment confirmed the biodegradation of dye mixture. Phytotoxicity study revealed the much less toxic nature of the metabolites produced after the degradation of dyes mixture.     

Glass-reinforced interacting blends of epoxy/polyurethane based on castor oil: Synthesis and characterization. II

Mechanical and dielectric properties of rubber mixtures of epoxy/polyurethane based on castor oil loaded with glass fiber is of great interest from a technological point of view. Epoxy resin was prepared from bisphenol A and epichlorohydrin in alkaline medium. Polyurethane was prepared from the hydroxyl group of castor oil reacted with 2,4-toluene diisocyanate. Elemental analysis and infrared (IR) spectra are presented as evidence for the formation of these materials. A homogeneous solution of epoxy resin and polyurethane was prepared in acetone containing a curing agent 1,3-propane diamine. The glass-reinforced laminates were prepared by interacting polymer blends on the glass fiber through compression moulding. Chemical resistance to solvents, flexural strength, izod impact strength, and Rockwell hardness studies on a series of specimens were investigated. It was observed that they behave as tough materials. An attempt was made to study the effect of electrical conductivity by changing the compositions of rubber mixtures during reinforcement with glass fibers. The dielectric constant (E′) dielectric loss (E″), and loss tangent (tan δ) of the specimens and their dependence of temperature was studied.