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

Effect of Buffer Layer and III/V Ratio on the Surface Morphology of GaN Grown by MBE

The surface morphology of GaN is observed by atomic force microscopy for growth on GaN and AlN buffer layers and as a function of III/V flux ratio. Films are grown on sapphire substrates by molecular beam epitaxy using a radio frequency nitrogen plasma source. Growth using GaN buffer layers leads to N-polar films, with surfaces strongly dependent on the flux conditions used. Flat surfaces can be obtained by growing as Ga-rich as possible, although Ga droplets tend to form. Ga-polar films can be grown on AlN buffer layers, with the surface morphology determined by the conditions of buffer layer deposition as well as the III/V ratio for growth of the GaN layer. Near-stoichiometric buffer layer growth conditions appear to support the flattest surfaces in this case. Three defect types are typically observed in GaN films on AlN buffers, including large and small pits and "loop" defects. It is possible to produce surfaces free from large pit defects by growing thicker films under more Ga-rich conditions. In such cases the surface roughness can be reduced to less than 1 nm RMS

Spraying calendar

Insects and fungi cause Iowa fruit growers and gardeners a loss which in the aggregate amounts to hundreds of thousands of dollars annually. They cause fruit and vegetables to rot and to be wormy and knotty or scabby; they damage blossoms and blossom buds and so interfere more or less with the setting of the fruit; they, destroy a vast amount of foliage or injure it in such a way as to interfere with its work of building up the special kinds of food which the plant must have in order properly to sustain its life, to support its growth, to form fruit buds for the following year, and to store away in its roots, trunk, and branches the reserve supply which it needs to support its active growth during the spring until the new leaves are fully developed and ready for work. Fortunately many of the worst of these insects and diseases may be kept well under control by proper, treatment as outlined in this spraying calendar. It is not best always to follow these general recommendations exactly. The strength of the mixtures and the number of treatments should be varied to fit special cases. It must be left for the manager of the work to decide this matter, but let him remember that, as a rule, the Iowa fruit grower who would be most successful under present conditions must spray systematically and thoroughly every year

A water-vapor electrolysis cell with phosphoric acid electrolyte

Feasibility of phosphoric acid water vapor electrolysis cell for spacecraft cabin air conditioning syste

Heat Rejection Systems Utilizing Composites and Heat Pipes: Design and Performance Testing

Polymer matrix composites offer the promise of reducing the mass and increasing the performance of future heat rejection systems. With lifetimes for heat rejection systems reaching a decade or more in a micrometeoroid environment, use of multiple heat pipes for fault tolerant design is compelling. The combination of polymer matrix composites and heat pipes is of particular interest for heat rejection systems operating on the lunar surface. A technology development effort is under way to study the performance of two radiator demonstration units manufactured with different polymer matrix composite face sheet resin and bonding adhesives, along with different titanium-water heat pipe designs. Common to the two radiator demonstration units is the use of high thermal conductivity fibers in the face sheets and high thermal conductivity graphite saddles within a light weight aluminum honeycomb core. Testing of the radiator demonstration units included thermal vacuum exposure and thermal vacuum exposure with a simulated heat pipe failure. Steady state performance data were obtained at different operating temperatures to identify heat transfer and thermal resistance characteristics. Heat pipe failure was simulated by removing the input power from an individual heat pipe in order to identify the diminished performance characteristics of the entire panel after a micrometeoroid strike. Freeze-thaw performance was also of interest. This paper presents a summary of the two radiator demonstration units manufactured to support this technology development effort along with the thermal performance characteristics obtained to date. Future work will also be discussed

Arkansas Cotton Variety Test 2020

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. Adaptation of varieties is determined by evaluating the lines at five University of Arkansas System Division of Agriculture research sites (Manila, Keiser, Judd Hill, Marianna, and Rohwer). Entries in the 2020 Arkansas Cotton Variety Test were evaluated in two groups—transgenic and conventional varieties. The 51 entries in the transgenic test included 7 B2XF, 30 B3XF, 12 W3FE, and 2 GLTP lines which were evaluated at all five locations. The conventional test included 10 entries which were evaluated at all locations except Manila. Reported data include lint yield, lint percentage, plant height, percent open bolls, yield component variables, fiber properties, leaf pubescence, stem pubescence, and bract trichome density. All entries in the experiments were evaluated for response to tarnished plant bug and bacterial blight in separate tests at Keiser. This 2020 report includes results of large-plot variety tests in 10 counties that were coordinated by Bill Robertson

The impact of COVID-19 lockdown measures on older residents' social connections and everyday wellbeing within housing schemes that provide care and support in England and Wales

The COVID-19 pandemic and the lockdown measures imposed as a result affected the lives of people in all parts of society across the world. In 2020, during the first UK national lockdown, older adults (aged 70 years and over) were told to ‘shield’ within their homes, as they were regarded as being at higher risk of serious COVID-19 infection compared to other age groups. This paper explores older adults' experiences of COVID-19 lockdown measures whilst living in housing with care schemes for older people. The purpose is to examine the impact of the lockdown measures on scheme life including social connections amongst residents and their general everyday wellbeing during this time. We present qualitative findings based on interviews with 72 residents who took part in longitudinal and cross-sectional interviews across 26 housing with care schemes. Data were analysed using a thematic framework approach to examine specifically their experiences of living in housing with care schemes during the 2020 UK lockdown. The paper highlights that COVID-19 restrictions had a detrimental impact on the social connections and interactions of older residents living in housing with care schemes, as well as on their feelings of autonomy and independence. Despite this, residents adapted and coped with self-isolation restrictions and sought out positive ways to maintain social contact with others inside and outside to the scheme. We further highlight the tensions that providers of housing for older adults faced in promoting residents' autonomy and connectedness whilst also trying to provide a safe living environment and protect residents from risk of COVID-19 infection. Our findings apply not only to a pandemic situation but to the broader understanding of how housing with care for older adults must navigate between autonomy and support

Arkansas Cotton Variety Test 2019

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. Adaptation of varieties is determined by evaluating the lines at five University of Arkansas System Division of Agriculture research sites (Manila, Keiser, Judd Hill, Marianna, and Rohwer). Entries in the 2019 Arkansas Cotton Variety Test were evaluated in two groups—transgenic and conventional varieties. The 50 entries in the transgenic test included 9 B2XF, 25 B3XF, 13 W3FE, and 3 GLTP lines which were evaluated at all five locations. The conventional test included 15 entries which were evaluated at all locations except Manila. Reported data include lint yield, lint percentage, plant height, percent open bolls, yield component variables, fiber properties, leaf pubescence, stem pubescence, and bract trichome density. All entries in the experiments were evaluated for response to tarnished plant bug and bacterial blight in separate tests at Keiser. This 2019 report includes results of large-plot variety tests in 10 counties that were coordinated by Bill Robertson