5,678 research outputs found

    Flexible seal for valves Patent

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    Flexible inflatable seal for butterfly valve

    X-ray photoemission characterization of La_{0.67}(Ca_{x}Sr_{1-x})_{0.33}MnO_{3} films

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    The Curie temperature and x-ray photoemission spectra of thin films of La_{0.67}(Ca_{x}Sr_{1-x})_{0.33}MnO_{3} (LCSMO) have been studied as a function of the Ca/Sr ratio. The films were grown by off-axis cosputtering from individual targets of La_{0.67}Ca_{0.33}MnO_{3} (LCMO) and La_{0.67}Sr_{0.33}MnO_{3} (LSMO) onto (100) oriented NdGaO_{3} substrates. The films grow with a (100) orientation, with no other orientations observed by x-ray diffraction. For the alloy mixtures, the Curie temperature, T_C, varies slowly as the Ca/Sr is decreased, remaining ≈\approx 300 K, while for the LCMO and LSMO films T_C is 260 and 330 K, respectively. The Mn-O valence structure is composed of two dominant peaks, whose positions undergo a change as the Ca fraction is decreased. The core lines behave as linear combinations of lines from pure LCMO and LSMO.Comment: 3 pages, 5 eps figures. To be published in Journal of Applied Physics (Proceedings of MMM'98

    The mineral nutrients in blue-grass

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    Characterization of transport and magnetic properties in thin film La(0.67)(Ca(x)Sr(1-x))(0.33)MnO(3) mixtures

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    We have grown thin films of (100) oriented La_{0.67}(Ca_{x}Sr_{1-x})_{0.33}MnO_{3} on (100) NdGaO_{3} substrates by off-axis sputtering. We have looked at the changes in the resistivity and magnetoresistance of the samples as the Ca/Sr ratio was varied. We find that as the calcium fraction is decreased, the lattice match to the substrate decreases, and the films become more disordered, as observed in transport measurements and the variation in Curie and peak resistance temperatures. We find a correlation between the temperature independent and T^2 terms to the low temperature resistivity. The room temperature magnetoresistance exhibits a maximum as the peak temperature is increased by the substitution of Sr for Ca, and a change in the field dependence to the resistivity at room temperature is observed.Comment: 5 pages, 6 eps figures, to be published in Journal of Applied Physic

    Tractor Driving Among Kentucky Farm Youth: Results from the Farm Family Health and Hazard Surveillance Project

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    This article documents the extent of children\u27s involvement in tractor operations among a representative sample of Kentucky children living and working on family farms. Specifically, we describe children\u27s exposures to tractor-related work activities, profile their use of the tractor (number of days worked), and assess compliance with generally recommended safety measures, such as using tractors equipped with ROPS (rollover protective structures), avoiding riding as passengers on tractors, and operating tractors on public roadways. Data for this study were collected in 1994 and 1995 as part of the NIOSH-sponsored Farm Family Health and Hazard Surveillance Project (FFHHSP). Despite recognition in the health and safety community of the hazards associated with operating tractors without ROPS on public roadways and with extra riders, these practices remain common among youth on Kentucky farms. Farms with annual incomes greater than $10,000, particularly with livestock commodities, appear to use youth for a greater number of days of tractor operation than other farms. Such farms may be an appropriate target for intervention

    Suicides Among Farmers in Three Southeastern States, 1990-1998

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    Several studies have documented higher rates of suicide among farmers in comparison to other occupational groups, both in the U.S. and internationally. The purpose of this study is to describe the epidemiology of farmer suicides in three southeastern states (Kentucky, North Carolina, and South Carolina) during the nine-year period 1990-1998. Electronic death certificate data were obtained from the National Center for Health Statistics. Over the nine-year period, there were 590 deaths related to suicide (E-codes: 950-959) among farmers (occupation codes: 473, 474, 475, 477, and 479) in the states of Kentucky, North Carolina, and South Carolina. The results of this study confirm the increased rate of suicide mortality among white male farmers in comparison to the total white male population in these three southern states. The increased rate of suicide was significantly elevated among farmers age 25-34 years (RR: 2.07; 95% CI: 1.61-2.67) and among those age 75-84 (RR: 2.04; 95% CI: 1.70-2.45) and age 85 years and older (RR: 2.67; 95% CI: 2.02-3.54) in comparison to the total white male population.The use of a firearm was the primary mechanism of death for the majority (86%) of the cases. Farmer suicide mortality rates in the southeastern U.S. are higher than in Midwestern states. The elevated rate of white male farmer suicides in North Carolina over this time period (35% higher age-adjusted suicide rate in comparison to South Carolina) suggests a need for further investigation to assess the individual, social, and economic factors that may explain this elevated rate. Interventions for the prevention of suicide need to be directed to older male farmers who consistently have higher suicide rates than similar males in other occupations

    Farm Work Injuries Among a Cohort of Children in Kentucky, USA

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    Children residing on farms with livestock may be at an increased risk for work-related injuries, compared to children who work on other commodity farms. This study characterizes children\u27s work tasks on Kentucky farms and assesses whether children who work on beef cattle farms are at an increased risk for farm work injuries. The results of a cohort study of children aged 5-18 years (N=999 at baseline) working on family farms in Kentucky, followed for two consecutive years after an initial enumeration five years previously, found that 70% of the children were involved in animal-related chores. Across all age groups, children on beef cattle farms devoted a greater number of hours per week to farm work, compared to children living on other commodity farms, especially during the school year. For all children in the study, working more than 180 days per year, performing farm work independently, and working on a beef cattle farm (compared to other commodity farm), increased the risk of a farm work injury. However, none of these associations were statistically significant. For male children only, the performance of work tasks independently was significantly associated with a 2.4-fold increased risk (OR = 2.41; 95% CI: 1.15-5.06; P=0.02) for a farm work injury, after controlling for days of working, age, period of data collection, and commodity type of the farm

    The Hidden Work of the Farm Homemaker

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    Despite women’s involvement in agricultural production, the work role of women residing in farm households has not been thoroughly examined. Data collected in 1994-1995 as part of the NIOSH-sponsored Farm Family Health and Hazard Surveillance Project were used to address task issues and health status of farm women in Kentucky. In 1996, the farm woman component of the Kentucky study was replicated in five counties in west Texas, allowing an examination of farm women in two large agricultural states. The Kentucky study employed a two-stage cluster design;the Texas study was based on a systematic quota sample of farms. Both studies selected a sample of women aged 18 years and older living in farm households. A total of 992 women in Kentucky (response rate = 85%) and 665 women in Texas completed a structured 30-min telephone interview on work roles, health status, injuries, and demographics. The results indicated that although 46.4% of the Kentucky respondents and 46.3% of the Texas respondents characterized themselves as farm homemakers, they regularly engaged in farmwork. Reported tasks included work with animals, tobacco-related chores, field irrigation, farm equipment operation, and farm management. Further, women who characterized themselves as homemakers reported rates of farm injuries that were comparable with women who classified themselves in other roles such as full agricultural partners. Role definition may influence the woman’s perception of risk on the farm, preclude participation in farm safety programs, and prevent an accurate occupational medical history. This two-state descriptive study highlights the hidden work role of the farm woman—a role that remains invisible to the farm woman herself—and emphasizes the important occupational exposures that farm women encounter
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