6,759 research outputs found

    Modelling Organic Dairy Production Systems

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    In this study, a large number of organic dairy production strategies were compared in terms of physical and financial performance through the integrated use of computer simulation models and organic case study farm data. Production and financial data from three organic case study farms were used as a basis for the modelling process to ensure that the modelled systems were based on real sets of resources that might be available to a farmer. The case study farms were selected to represent a range of farming systems in terms of farm size, concentrate use and location. This paper describes the process used to model the farm systems: the integration of the three models used and the use of indicators to assess the modelled farm systems in terms of physical sustainability and financial performance

    Analysis of a novel non-contacting waveguide backshort

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    A new non-contacting waveguide backshort has been developed for millimeter and submillimeter wave frequencies. The design consists of a metal bar with rectangular or circular holes cut into it, which is covered with a dielectric (mylar) layer to form a snug fit with the walls of a waveguide. Hole geometries are adjusted to obtain a periodic variation of the guide impedance on the correct length scale, in order to produce efficient reflection of RF power. It is a mechanically rugged design which can be easily fabricated for frequencies from 1 to 1000 GHz and is thus a sound alternative to the miniaturization of conventional non-contacting shorts. To aid in high-frequency design, a rigorous full-wave analysis has been completed, which will allow variations of the size, number and spacing of the holes to be easily analyzed. This paper will review the backshort design and the method developed for theoretical characterization, followed by a comparison of the experimental and numerical results. Low frequency models operating from 4-6 GHz are shown to demonstrate return loss of greater than -0.2 dB over a 33 percent bandwidth. The theory is in good agreement with measured data

    Prediction of a surface state and a related surface insulator-metal transition for the (100) surface of stochiometric EuO

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    We calculate the temperature and layer-dependent electronic structure of a 20-layer EuO(100)-film using a combination of first-principles and model calculation based on the ferromagnetic Kondo-lattice model. The results suggest the existence of a EuO(100) surface state which can lead to a surface insulator-metal transition.Comment: 9 pages, 5 figures, Phys. Rev. Lett. (in press

    ā€œI wish Iā€™d told themā€: a qualitative study examining the unmet psychosexual needs of prostate cancer patients during follow-up after treatment

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    <b>Objective</b> To gain insight into patients' experiences of follow-up care after treatment for prostate cancer and identify unmet psychosexual needs.<p></p> <b>Methods</b> Semi-structured interviews were conducted with a purposive sample of 35 patients aged 59-82 from three UK regions. Partners were included in 18 interviews. Data were analyzed using constant comparison. <p></p> <b>Results</b> (1) Psychosexual problems gained importance over time, (2) men felt they were rarely invited to discuss psychosexual side effects within follow-up appointments and lack of rapport with health care professionals made it difficult to raise problems themselves, (3) problems were sometimes concealed or accepted and professionals' attempts to explore potential difficulties were resisted by some, and (4) older patients were too embarrassed to raise psychosexual concerns as they felt they would be considered 'too old' to be worried about the loss of sexual function.<p></p> <b>Conclusion</b> Men with prostate cancer, even the very elderly, have psychosexual issues for variable times after diagnosis. These are not currently always addressed at the appropriate time for the patient.Practice implications Assessments of psychosexual problems should take place throughout the follow-up period, and not only at the time of initial treatment. Further research examining greater willingness or reluctance to engage with psychosexual interventions may be particularly helpful in designing future intervention

    An observational prospective study of topical acidified nitrite for killing methicillin-resistant Staphylococcus aureus (MRSA) in contaminated wounds

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    Background Endogenous nitric oxide (NO) kills bacteria and other organisms as part of the innate immune response. When nitrite is exposed to low pH, NO is generated and has been used as an NO delivery system to treat skin infections. We demonstrated eradication of MRSA carriage from wounds using a topical formulation of citric acid (4.5%) and sodium nitrite (3%) creams co-applied for 5 days to 15 wounds in an observational prospective pilot study of 8 patients. Findings Following treatment with topical citric acid and sodium nitrite, 9 of 15 wounds (60%) and 3 of 8 patients (37%) were cleared of infection. MRSA isolates from these patients were all sensitive to acidified nitrite in vitro compared to methicillin-sensitive S. aureus and a reference strain of MRSA. Conclusions Nitric oxide and acidified nitrite offer a novel therapy for control of MRSA in wounds. Wounds that were not cleared of infection may have been re-contaminated or the bioavailability of acidified nitrite impaired by local factors in the tissue

    Correlation of Starch Recovery with Assorted Quality Factors of Four Corn Hybrids

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    A laboratory wet-milling process was developed for use in determining starch recovery of yellow dent corn. The effects of harvest moisture and drying air temperature on starch recovery were investigated for four hybrids. A split split-plot experimental design was used to evaluate the effects. Starch recovery was not significantly different among the hybrids; however, it did decreases both harvest moisture and drying air temperature increased. Starch recovery was correlated with quantitative measures of assorted quality factors. Regression analysis found starch recovery to be a function of starch content, test weight, and ethanol-soluble protein

    Correlation of Starch Recovery with Assorted Quality Factors of Four Corn Hybrids

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    A laboratory wet-milling process was developed for use in determining starch recovery of yellow dent corn. The effects of harvest moisture and drying air temperature on starch recovery were investigated for four hybrids. A split split-plot experimental design was used to evaluate the effects. Starch recovery was not significantly different among the hybrids; however, it did decreases both harvest moisture and drying air temperature increased. Starch recovery was correlated with quantitative measures of assorted quality factors. Regression analysis found starch recovery to be a function of starch content, test weight, and ethanol-soluble protein

    Beyond the random phase approximation in the Singwi-Sj\"olander theory of the half-filled Landau level

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    We study the Ī½=1/2\nu=1/2 Chern-Simons system and consider a self-consistent field theory of the Singwi-Sj\"olander type which goes beyond the random phase approximation (RPA). By considering the Heisenberg equation of motion for the longitudinal momentum operator, we are able to show that the zero-frequency density-density response function vanishes linearly in long wavelength limit independent of any approximation. From this analysis, we derive a consistency condition for a decoupling of the equal time density-density and density-momentum correlation functions. By using the Heisenberg equation of motion of the Wigner distribution function with a decoupling of the correlation functions which respects this consistency condition, we calculate the response functions of the Ī½=1/2\nu=1/2 system. In our scheme, we get a density-density response function which vanishes linearly in the Coulomb case for zero-frequency in the long wavelength limit. Furthermore, we derive the compressibility, and the Landau energy as well as the Coulomb energy. These energies are in better agreement to numerical and exact results, respectively, than the energies calculated in the RPA.Comment: 9 Revtex pages, 4 eps figures, typos correcte

    Remote Laser Welding of Multi-Alloy Aluminum at Close-Edge Position

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    Abstract6000 series (magnesium and silicon based) aluminum alloys are highly susceptible to hot cracking during laser beam welding. The occurrence of hot cracks depends on thermo-mechanical strain at the solidifying stage of the melt and in the micro-scale on the solidification structure. A new metallurgical approach to avoid these cracks by affecting the solidification process is using a multi-alloy aluminum with a silicon-rich layer. Within this paper infrared videos were used to investigate and compare the behavior of this new material with the 6xxx monolithic alloy at hot crack sensitive close-edge positions
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