4,880 research outputs found

    Development of Design Criteria for Sensitizer Photooxidation Treatment Systems

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    Sensitized photooxidation is a physicochemical process that can degrade many toxic and refractory organic pollutants. A trace quantity of sensitizer added to the waste absorbs visible light; electronically excited intermediates then transfer the energy to decompose the waste. Engeineering design criteria were developed for industrial waste treatment lagoons that would use sensitized photooxidation. Design criteria were developed regarding optimum lagoon pH, optimum sensitizer concentration, depth and sizing of lagoons, dissolved oxygen requirements, and effect of temperature on photooxidation rate. Treatment of the refractory pesticides bromacil, terbacil, and fluometuron was investigated using methylene blue and riboflavin as sensitizers. Methylene blue-sensitized photooxidation of the three pesticides was most efficient at basic pH. The optimum pH of riboflavin-sensitized photooxidaction varied and was substrate-dependent. A model was developed to predict sensitized photooxidation rate as a function of lagoon depth. The model is based on light intesnity, sensitizer extinction coefficient, and an applied quantum yeirld, all of which are integrated over wavelengths of visible light. The model serves as the basis of sizing photooxidation lagoons. A dissolved oxygen residual of 1 mg/1 was required to maintain maximum methylene blue-sensitized photooxidation rate. At least 4 mg/1 dissolved oxygen was necessary to maintain riboflavin-sensitized phooxidation at maximum levels. Oxygen uptake rates in sensitized phooxidation reactions were proportional to the concentration of substrate. Temperatures from 10 degrees to 35 degreees Celcius had no significant effect on sensitized photooxidation rates. Using the model developed, a methylene blue-sensitized phooxidation pilot lagoon was designed to treat a 30 mg/1 bromacil influent concentraion to 0.1 mg/1 bromacil in the effluent. For an influent flow of 0.263 m^3/min (0.1 MGD) waste, a 0.1 mg/1 methylene blue concentration, 36 cm depth, and 1870 m^2 surface area are required. A cost analysis was performed which indicated that sensitized photooxidation lagoons appear to be cost-compentitive with other industrial waste treatement systems

    Utilization of Corn Co-Products in the Beef Industry

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    Corn milling co-products are expected to increase dramatically in supply. Two primary types of milling processes currently exist, resulting in quite different feed products. The dry milling process produces distillers grains plus solubles, and the wet milling process produces corn gluten feed. These feeds can be marketed as wet feed, or they can be dried and marketed as either dry corn gluten feed or dry distillers grains with or without solubles. For the purposes of this article, only wet corn gluten feed (WCGF) and wet distillers grains plus solubles (WDGS) will be discussed. The majority of plant expansions are dry milling plants that produce WDGS; however, an increase in supply of WCGF is also expected. Therefore, these feeds may be very attractive for beef producers to use as an energy source. This article will focus on the production, composition of these feeds, energy values, and economics of using WDGS. Some other management issues will be discussed as well including grain processing when these co-products are used in feedlot diets, roughage level when these co-products are used, and feeding combinations of WDGS and WCGF. Forage fed situations will be covered with dried co-products as this will be the most common application for both energy and protein supplementation in many forage feeding situations

    Utilization of Corn Co-Products in the Beef Industry

    Get PDF
    Corn milling co-products are expected to increase dramatically in supply. Two primary types of milling processes currently exist, resulting in quite different feed products. The dry milling process produces distillers grains plus solubles, and the wet milling process produces corn gluten feed. These feeds can be marketed as wet feed, or they can be dried and marketed as either dry corn gluten feed or dry distillers grains with or without solubles. For the purposes of this article, only wet corn gluten feed (WCGF) and wet distillers grains plus solubles (WDGS) will be discussed. The majority of plant expansions are dry milling plants that produce WDGS; however, an increase in supply of WCGF is also expected. Therefore, these feeds may be very attractive for beef producers to use as an energy source. This article will focus on the production, composition of these feeds, energy values, and economics of using WDGS. Some other management issues will be discussed as well including grain processing when these co-products are used in feedlot diets, roughage level when these co-products are used, and feeding combinations of WDGS and WCGF. Forage fed situations will be covered with dried co-products as this will be the most common application for both energy and protein supplementation in many forage feeding situations

    SBSI:an extensible distributed software infrastructure for parameter estimation in systems biology

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    Complex computational experiments in Systems Biology, such as fitting model parameters to experimental data, can be challenging to perform. Not only do they frequently require a high level of computational power, but the software needed to run the experiment needs to be usable by scientists with varying levels of computational expertise, and modellers need to be able to obtain up-to-date experimental data resources easily. We have developed a software suite, the Systems Biology Software Infrastructure (SBSI), to facilitate the parameter-fitting process. SBSI is a modular software suite composed of three major components: SBSINumerics, a high-performance library containing parallelized algorithms for performing parameter fitting; SBSIDispatcher, a middleware application to track experiments and submit jobs to back-end servers; and SBSIVisual, an extensible client application used to configure optimization experiments and view results. Furthermore, we have created a plugin infrastructure to enable project-specific modules to be easily installed. Plugin developers can take advantage of the existing user-interface and application framework to customize SBSI for their own uses, facilitated by SBSI’s use of standard data formats

    Differential Test Performance in the American Educational System: The Impact of Race and Gender

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    Contrary to Herrnstein and Murray (1994) who claim that racial groups have different cognitive endowments and that these best explain differential test score achievements, our regression analyses document that there is less improvement in test scores per year of education for African-Americans and women. That is, the observed group test score differences do not appear to be due to racial cognitive differences but rather to other factors associated with group-linked experiences in the educational system. We found that 666 of the subjects in the Herrnstein-Murray database had actual IQ scores derived from school records. Using these as independent controls for IQ, we document that each of the test components that were the basis of the Herrnstein-Murray IQ scores was significantly associated with education level (p\u3c .001). Consequently, their IQ score appears to be an education-related measure rather than an IQ test, and thus challenges the validity of their analysis

    A Review of Corn Stalk Grazing on Animal Performance and Crop Yield

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    The highest cost to beef cow-calf and backgrounding operations is the feeding of stored feeds in winter months. Nebraska has an abundance of corn fields available for grazing following harvest. Utilization of corn crop residue is quite effective in reducing feed costs. There are a number of important considerations associated with residue utilization. Stocking rates, diet quality, genetically modified corn, subsequent crop yields and supplementation are discussed

    A Review of Corn Stalk Grazing on Animal Performance and Crop Yield

    Get PDF
    The highest cost to beef cow-calf and backgrounding operations is the feeding of stored feeds in winter months. Nebraska has an abundance of corn fields available for grazing following harvest. Utilization of corn crop residue is quite effective in reducing feed costs. There are a number of important considerations associated with residue utilization. Stocking rates, diet quality, genetically modified corn, subsequent crop yields and supplementation are discussed

    Report of the panel on the land surface: Process of change, section 5

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    The panel defined three main areas of study that are central to the Solid Earth Science (SES) program: climate interactions with the Earth's surface, tectonism as it affects the Earth's surface and climate, and human activities that modify the Earth's surface. Four foci of research are envisioned: process studies with an emphasis on modern processes in transitional areas; integrated studies with an emphasis on long term continental climate change; climate-tectonic interactions; and studies of human activities that modify the Earth's surface, with an emphasis on soil degradation. The panel concluded that there is a clear requirement for global coverage by high resolution stereoscopic images and a pressing need for global topographic data in support of studies of the land surface

    Multiabsorber Transition-Edge Sensors for X-Ray Astronomy

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    We are developing arrays of position-sensitive microcalorimeters for future x-ray astronomy applications. These position-sensitive devices commonly referred to as hydras consist of multiple x-ray absorbers, each with a different thermal coupling to a single-transition-edge sensor microcalorimeter. Their development is motivated by a desire to achieve very large pixel arrays with some modest compromise in performance. We report on the design, optimization, and first results from devices with small pitch pixels (<75 m) being developed for a high-angular and energy resolution imaging spectrometer for Lynx. The Lynx x-ray space telescope is a flagship mission concept under study for the National Academy of Science 2020 decadal survey. Broadband full-width-half-maximum (FWHM) resolution measurements on a 9-pixel hydra have demonstrated E(FWHM) = 2.23 0.14 eV at Al-K, E(FWHM) = 2.44 0.29 eV at Mn-K, and E(FWHM) = 3.39 0.23 eV at Cu-K. Position discrimination is demonstrated to energies below <1 keV and the device performance is well-described by a finite-element model. Results from a prototype 20-pixel hydra with absorbers on a 50-m pitch have shown E(FWHM) = 3.38 0.20 eV at Cr-K1. We are now optimizing designs specifically for Lynx and extending the number of absorbers up to 25/hydra. Numerical simulation suggests optimized designs could achieve 3 eV while being compatible with the bandwidth requirements of the state-of-the art multiplexed readout schemes, thus making a 100,000 pixel microcalorimeter instrument a realistic goal
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