University of Arkansas

About: University of Arkansas is a education organization based out in Fayetteville, Arkansas, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 17225 authors who have published 33329 publications receiving 941102 citations. The organization is also known as: Arkansas & UA.

An optically pumped 2.5 μm GeSn laser on Si operating at 110 K

Abstract: This paper reports the demonstration of optically pumped GeSn edge-emitting lasers grown on Si substrates The whole device structures were grown by an industry standard chemical vapor deposition reactor using the low cost commercially available precursors SnCl4 and GeH4 in a single run epitaxy process Temperature-dependent characteristics of laser-output versus pumping-laser-input showed lasing operation up to 110 K The 10 K lasing threshold and wavelength were measured as 68 kW/cm2 and 2476 nm, respectively Lasing characteristic temperature (T0) was extracted as 65 K

Collision detection: A survey

Abstract: A process of determining whether two or more bodies are making contact at one or more points is called collision detection or intersection detection Collision detection is inseparable part of the computer graphics, surgical simulations, and robotics There are varieties of methods for collision detection We will review some of the most common ones Algorithms for contact determination can be grouped into two general parts: broad-phase and narrow-phase This paper provides a comprehensive classification of a collision detection literature into the two phases Moreover, we have attempted to explain some of the existing algorithms which are not easy to interpret Also, we have tried to keep sections self-explanatory without sacrificing depth of coverage

A review of SiC power module packaging: Layout, material system and integration

Abstract: Silicon-Carbide (SiC) devices with superior performance over traditional silicon power devices have become the prime candidates for future high-performance power electronics energy conversion. Traditional device packaging becomes a limiting factor in fully realizing the benefits offered by SiC power devices, and thus, improved and advanced packaging structures are required to bridge the gap between SiC devices and their applications. This paper provides a review of the state-of-art advanced module packaging technologies for SiC devices with the focuses on module layout, packaging material system, and module integration trend, and links these packaging advancements to their impacts on the SiC device performances. Through this review, the paper discusses main challenges and potential solutions for SiC modules, which is critical for future SiC applications.

Household Demand in Rural China: A Two-Stage LES-AIDS Model

Abstract: A complete demand system of Chinese rural households is estimated using a two-stage LES-AIDS model and pooled provincial and time-series data from 1982 to 1990. For commodity groups (food, clothing, fuel, housing, and other commodities), demand is price-inelastic. Housing and other commodities are luxury goods, while clothing and food are necessities. Within the food group, price elasticities range from −0.005 to −0.63. Expenditure elasticities are lower for grains and higher for meat, tobacco, and alcohol. The results imply a gap between food demand and supply growth. Therefore, China will face pressure to import food.

Rhizosphere microbial populations in contaminated soils

Abstract: Rhizosphere microbial populations may increase bioremediation of soil contaminated with organic chemicals. A growth chamber study was conducted to evaluate rhizosphere microbial populations in contaminated and non-contaminated soil. Alfalfa (Medicago sativa L.) and alpine bluegrass (Poa alpina L.) were grown in soil containing a mixture of organic chemicals for 14 weeks. The equal millimolar mixture of hexadecane, (2,2-dimethyl-propyl)-benzene, cis-decahydronaphthalene (decalin), benzoic acid, phenanthrene, and pyrene was added at levels of 0 and 2000 mg/kg. Organic chemical degrader (OCD) populations were assessed by a Most-Probable-Number technique, and bacteria and fungi were enumerated by plate count methods. Different methods for expressing OCD rhizosphere populations were investigated to determine the effect it had on interpretation of the results. At 9 weeks, the OCD numbers were significantly higher in rhizosphere and contaminated soils than in bulk and non-contaminated soils, respectively. Alfalfa rhizosphere OCD levels were 4 × 107/g for contaminated and 6 × 106/g for non-contaminated soils. Bluegrass rhizosphere OCD levels were 1 × 107/g and 1 × 106/g in contaminated and non-contaminated soils, respectively. Selective enrichment of OCD populations was observed in contaminated rhizosphere soil. Higher numbers of OCD in contaminated rhizospheres suggest potential stimulation of bioremediation around plant roots.