Using Digital Tools to Foster Critical Inquiry

How do adolescents use digital media as tools in ways that go beyond simply extracting information or playing games to engaging in the literacy practices involved in critical inquiry activities?published or submitted for publicationis peer reviewe

Nickel layers on indium arsenide

We report here on the preparation and characterization of InAs substrates for in situ deposition of ferromagnetic contacts, a necessary precursor for semiconductor devices based on spin injection. InAs has been grown on InAs(111)A and (100) substrates by molecular-beam epitaxy and then metalized in situ in order to better understand the mechanisms that inhibit spin injection into a semiconductor. Initial x-ray characterization of the samples indicate the presence of nickel arsenides and indium–nickel compounds forming during deposition at temperatures above room temperature. Several temperature ranges have been investigated in order to determine the effect on nickel-arsenide formation. The presence of such compounds at the interface could greatly reduce the spin-injection efficiency and help elucidate previous unsuccessful attempts at measuring spin injection into InAs

Arkansas Cotton Variety Test 2013

The primary goal of the Arkansas Cotton Variety Test is to provide unbiased data regarding the agronomic performance of cotton varieties and advanced breeding lines in the major cotton-growing areas of Arkansas. This information helps seed companies establish marketing strategies and assists producers in choosing varieties to plant. These annual evaluations will then facilitate the inclusion of new, improved genetic material in Arkansas cotton production

Can switching fuels save water? A life cycle quantification of freshwater consumption for Texas coal-and natural gas-fired electricity

Thermal electricity generation is a major consumer of freshwater for cooling, fuel extraction and air emissions controls, but the life cycle water impacts of different fossil fuel cycles are not well understood. Much of the existing literature relies on decades-old estimates for water intensity, particularly regarding water consumed for fuel extraction. This work uses contemporary data from specific resource basins and power plants in Texas to evaluate water intensity at three major stages of coal and natural gas fuel cycles: fuel extraction, power plant cooling and power plant emissions controls. In particular, the water intensity of fuel extraction is quantified for Texas lignite, conventional natural gas and 11 unconventional natural gas basins in Texas, including major second-order impacts associated with multi-stage hydraulic fracturing. Despite the rise of this water-intensive natural gas extraction method, natural gas extraction appears to consume less freshwater than coal per unit of energy extracted in Texas because of the high water intensity of Texas lignite extraction. This work uses new resource basin and power plant level water intensity data to estimate the potential effects of coal to natural gas fuel switching in Texas’ power sector, a shift under consideration due to potential environmental benefits and very low natural gas prices. Replacing Texas’ coal-fired power plants with natural gas combined cycle plants (NGCCs) would reduce annual freshwater consumption in the state by an estimated 53 billion gallons per year, or 60% of Texas coal power’s water footprint, largely due to the higher efficiency of NGCCs.Mechanical Engineerin