322 research outputs found
Solution of large linear systems of equations on the massively parallel processor
The Massively Parallel Processor (MPP) was designed as a special machine for specific applications in image processing. As a parallel machine, with a large number of processors that can be reconfigured in different combinations it is also applicable to other problems that require a large number of processors. The solution of linear systems of equations on the MPP is investigated. The solution times achieved are compared to those obtained with a serial machine and the performance of the MPP is discussed
Addressing Barriers to Physical Activity in Vermont\u27s Geriatric Population
A wide array of barriers exist which prevent many geriatric patients from engaging in regular physical activity. This project addresses the barriers unique to Vermont\u27s population of geriatric patients and explores potential solutions.https://scholarworks.uvm.edu/fmclerk/1631/thumbnail.jp
ANALYSIS OF GREENSIDE BUNKER SHOTS IN GOLF
This paper presents an analysis of greenside sand bunker shots in golf to identify the key parameters in a given situation to achieve the desired distance to the pin. Different depths and corresponding entry distances of a down swing were measured in order to analyse the situation. Experiments for taking the required data were conducted in a sand bunker of a golf course. Samples were taken from different golfers whose handicaps are ranging from 5 to 25. Results can be used to train amateur golfers, especially for reaching different distances towards the pin from greenside sand bunkers
Soil quality parameters for row-crop systems and grazed pastures with agroforestry buffers
Paper presented at the 12th North American Agroforesty Conference, which was held June 4-9, 2011 in Athens, Georgia.In Ashton, S. F., S.W. Workman, W.G. Hubbard and D.J. Moorhead, eds. Agroforestry: A Profitable Land Use. Proceedings, 12th North American Agroforestry Conference, Athens, GA, June 4-9, 2011.Incorporation of trees and establishment of buffer are believed to enhance soil quality. Soil enzyme activities and water stable aggregates have been identified as good indices for assessing soil quality to evaluate early responses to changes in soil management. However, studies comparing these parameters for grazing pastures and row crop systems are limited. The objective of this study is to examine the activities of selected enzymes (fluorescein diacetate (FDA) hydrolase, dehydrogenase, [beta]-glucosidase and [beta]-glucosaminidase), the percentage of water stable aggregates (WSA), and soil organic carbon and nitrogen as soil quality parameters for grazed pasture and row-crop systems. The study consisted of four management treatments: grazed pasture (GP), agroforestry buffer (AgB), grass buffer (GB) and row-crop (RC). Soil organic carbon (SOC), total nitrogen (TN) contents and soil bulk density were also determined. Two soil depths (0-10 and 10-20 cm) were analyzed for all treatments for two consecutive years, 2009 and 2010. The row-crop treatment showed significantly lower [beta]-glucosidase and [beta]-glucosaminidase activity and significantly lower WSA compared to all other treatments. The FDA hydrolase activities were not significant in 2009 but were significant in 2010. There were numerical variations of parameters in two years but the pattern was consistent. Surface soil revealed higher enzyme activities and higher WSA than the sub-surface soil. The treatment by depth interactions were significant for [beta]-glucosidase and [beta]-glucosaminidase enzymes in 2009 but the interactions were significant for dehydrogenase and [beta]-glucosaminidase enzymes in 2010. Implications can be made that permanent vegetation will improve soil quality by enhancing organic matter accumulation in the soil and increasing microbial activity with minimum soil disturbance which will have a positive effect on the ecosystems.Bodh Paudel (1), Ranjith Udawatta (1,2), Stephen H. Anderson (1) and Robert Kremer (3) ; 1. Soil, Environmental and Atmospheric Sciences, 302 Anheuser-Busch Natural Resources Building, University of Missouri, Columbia, MO, USA. 2. Center for Agroforestry, 203 Anheuser-Busch Natural Resources Building, University of Missouri, Columbia, MO, USA. 3. USDA-ARS Cropping Systems and Water Quality Unit, University of Missouri, Columbia, MO, USA.Includes bibliographical references
CT-measured macropores as affected by agroforestry and grass buffers for grazed pasture systems
Paper presented at the 11th North American Agroforesty Conference, which was held May 31-June 3, 2009 in Columbia, Missouri.In Gold, M.A. and M.M. Hall, eds. Agroforestry Comes of Age: Putting Science into Practice. Proceedings, 11th North American Agroforestry Conference, Columbia, Mo., May 31-June 3, 2009.Agroforestry and grass buffers have been proposed for improving water quality in watersheds. Buffer vegetation influences soil porosity, essential for water, gas and nutrient transport in soils. The objective of the study was to compare differences in CT-measured macropore ([greater than] 1000-[micro] m diam.) and coarse mesopore (200- to 1000-[micro] m diam.) parameters within agroforestry (AgB) and grass buffer (GB) systems associated with rotationally grazed (RG) and continuously grazed (CG) pasture systems, and to examine relationships between CT-measured pore parameters and saturated hydraulic conductivity (K[subscript]sat). Soils at the site were Menfro silt loam (fine-silty, mixed, superactive, mesic Typic Hapludalf). Six replicate intact soil cores, 76.2 mm diam. by 76.2 mm long, were collected using a core sampler from the four treatments at five soil depths (0-50 cm at 10-cm intervals). Image-J software was used to analyze the five equally spaced images from each core. CT-measured soil macroporosity ([greater than] 1000 [micro] m diam.) was 13 times higher (0.053 m3m3) for the buffer treatments compared to the pasture treatments (0.004 m3m3) for the surface 0-10 cm soil depth. Buffer treatments had greater macroporosity (0.020 m3m3) compared to pasture (0.0045 m3m3) treatments. The K[subscript sat] values for buffer treatments were five times higher and bulk density was 5.6 [percent] lower compared to pasture treatments. CT-measured pore parameters (except macropore circularity) were positively correlated with K[subscript sat]. This study illustrates the benefits of agroforestry and grass buffers for maintaining soil pore parameters critical for soil water and nutrient transport.Sandeep Kumar (1), Stephen H. Anderson (1), and Ranjith P. Udawatta (1, 2) ; 1. Department of Soil, Environmental and Atmospheric Sciences, University of Missouri- Columbia. 2. Center for Agroforestry, University of Missouri-Columbia. Columbia, MO 65211, USA.Includes bibliographical references
Agroforestry and grass buffer effects on water quality on grazed pasture watersheds
Paper presented at the 11th North American Agroforesty Conference, which was held May 31-June 3, 2009 in Columbia, Missouri.In Gold, M.A. and M.M. Hall, eds. Agroforestry Comes of Age: Putting Science into Practice. Proceedings, 11th North American Agroforestry Conference, Columbia, Mo., May 31-June 3, 2009.Conservation practices including agroforestry and grass buffers are believed to reduce non point source pollution (NPSP) from grazed pasture watersheds. Agroforestry, a land management practice that intersperses agricultural crops with trees, recently received increased attention in the temperate zone due to its environmental and economic benefits. However, studies are limited that examined buffer effects on water quality on grazed pasture watersheds. Six small watersheds, two with agroforestry buffers, two with grass buffers, and two control watershdeds were used to test the hypothesis that agroforestry and grass buffers reduce NPSP from grazed pasture watersheds. Vegetation in grass buffer and pasture areas include red clover (Trifolium pretense L.) and lespedeza (Kummerowia stipulacea Maxim.) planted into fescue (Festuca arundinacea Schreb.). Eastern cottonwood trees (Populus deltoids Bortr. ex Marsh.) were planted into fescue in agroforestry buffers. Soils at the site are mostly Menfro silt loam (fine-silty, mixed, superactive, mesic Typic Hapludalfs). Watersheds were instrumented with two-foot H flumes, water samplers, and flow measuring devices in 2001. Composite water samples were analyzed for sediment, and total nitrogen after each runoff event to compare treatment differences. Watersheds with agroforerstry and grass buffers had significantly lower runoff volumes as compared to the control watersheds. The loss of sediment, and total nitrogen were smaller for the buffer watersheds. The results of the study suggest that establishment of groforestry and grass buffers help reduce NPSP pollution from grazed pasture watersheds. It is anticipated as trees grow and roots occupy more soil volume, the reduction in N in runoff should increase on the agroforestry watershed.Ranjith P. Udawatta (1, 2), Harold E. Garrett (2), and Robert L. Kallenbach (3) ; 1. Department of Soil, Environmental and Atmospheric Sciences. 2. Center for Agroforestry. 3. Department of Plant Sciences, University of Missouri, Columbia, MO 65211.Includes bibliographical references
Agroforestry and grass buffer influences on water infiltration for a grazed pasture system
Paper presented at the 11th North American Agroforesty Conference, which was held May 31-June 3, 2009 in Columbia, Missouri.In Gold, M.A. and M.M. Hall, eds. Agroforestry Comes of Age: Putting Science into Practice. Proceedings, 11th North American Agroforestry Conference, Columbia, Mo., May 31-June 3, 2009.Agroforestry and grass buffers are often adopted as an alternative resource management system in agriculture for environmental and economic benefits. The objective of the study was to compare agroforestry (AgB) and grass buffer (GB) systems under rotationally grazed (RG) and continuously grazed (CG) pasture systems on water infiltration measured using ponded infiltration and tension infiltration methods. Buffer areas were fenced which prevented cattle grazing in buffer areas. Soils at the site are Menfro silt loam (fine-silty, mixed, superactive, mesic Typic Hapludalfs). Infiltration rates were measured using ponded ring infiltration units in 2007 and 2008 for the four treatments with six replicates. Infiltration rate as a function of tension (at 50-, 100-, and 150-mm) was also measured using a tension infiltrometer in 2007. Water infiltration parameters were estimated using Green-Ampt and Parlange infiltration equations. Quasi-steady state infiltration rates (qs) and field-saturated hydraulic conductivity (Kfs) for the buffers were about 30 and 40 times higher compared to pasture treatments, respectively. Green-Ampt and Parlange models appeared to fit measured data with r2 values ranging between 0.91 to 0.98. The infiltration rate in 2007 for the GB treatment was the highest (221.4 mm h-1) and for the CG treatment was the lowest (3.73 mm h-1). Estimated sorptivity (S) and saturated hydraulic conductivity (Ks) parameters were higher for buffers compared to the pasture treatments. Grazing reduced infiltration rates for the pasture (CG and RG) treatments. Results show that the buffer areas have higher infiltration rates which imply lower runoff compared to pasture areas.Sandeep Kumar (1), Stephen H. Anderson (1), Ranjith P. Udawatta (1,2), and Robert L. Kallenbach (3) ; 1. Soil, Environmental and Atmospheric Sciences, University of Missouri-Columbia. 2. Center for Agroforestry, University of Missouri-Columbia. 3. Division of Plant Sciences, University of Missouri-Columbia Columbia, MO 65211, USA.Includes bibliographical references
Microclimate studies of crop environments under different agroforestry arrangements [abstract]
Abstract only availableOne of the factors influencing crop yields is evapotranspiration; the evaporation of water from both plants and soil. Soil moisture provides many nutrients to crops, so evapotranspiration rates are of concern. This study will focus on the environmental conditions above crop fields in Northeastern Missouri and see which conditions lead to higher evapotranspiration rates. The fields also contain two kinds of buffers: a tree and a grass buffer. Weather instrumentation was placed above the crops between the different buffers and data was collected in regular intervals throughout each day over the past two years. The first year the crop was corn, and soybeans the second year. Some of the variables looked at include temperature, humidity, net radiation, wind speed, and wind direction. In this project a comparison is made between the conditions over soybeans between the tree and grass buffer to see which buffer creates which environmental conditions. The main hypothesis was that grass buffers would lead to higher evapotranspiration rates due to higher winds (grass being shorter than trees) advecting moisture away. Evapotranspiration rates were derived using a Penman equation and, using MATLAB, graphs were made of each of the variables using 10-day averages. It was determined that the hypothesis was correct by looking at the data output qualitatively. However, the significance of the difference between the grass and agroforestry buffers has yet to be found since the time period used in the Penman equation is questionable. Therefore the equations used thus far will be examined thoroughly and modified if need be to set the quantitative data to the correct time period. In this results will be obtained that will be more understandable to the general public and science community.CAFNR On Campus Research Internshi
APEX simulation : environmental benefits of agroforestry buffers on corn-soybean watersheds
Paper presented at the 13th North American Agroforesty Conference, which was held June 19-21, 2013 in Charlottetown, Prince Edward Island, Canada.In Poppy, L., Kort, J., Schroeder, B., Pollock, T., and Soolanayakanahally, R., eds. Agroforestry: Innovations in Agriculture. Proceedings, 13th North American Agroforestry Conference, Charlottetown, Prince Edward Island, Canada, June 19-21, 2013.The Agricultural Policy Environmental Extender (APEX) model has the ability to simulate the effects of vegetative filter strips on runoff and pollutant loadings from agricultural watersheds. The objectives of this study were to calibrate and validate the APEX model for three adjacent watersheds and determine optimum buffer dimensions and placement locations. ArcAPEX and APEX0604 versions were used for the simulations. The simulated corn and soybean yields were within 13% and 27% of the measured yields, respectively. The agroforestry, grass buffer, and control watershed models were calibrated (1998 to 2001) and validated (2002 to 2008) for eventbased runoff with r2 and Nash-Sutcliffe Coefficients (NSC) values of 0.7-0.8 and 0.4-0.8, respectively. The models could not be calibrated for sediment losses. The simulated grass and agroforestry buffers reduced average annual runoff by 5.2% and 4.3%, respectively. Increase of buffer widths to 5.5 m and 7.5 m were not effective. The buffers located on the backslopes were the most effective for the agroforestry watershed but this trend was not seen in the grass buffer watershed. The study provides guidance on how to parameterize APEX to simulate grass and agroforestry buffers. It contributes to the validation of APEX and will be useful to scientists in need of parameterizing the model for watersheds that include upland buffers.Anomaa Senaviratne (1, 2), Ranjith P. Udawatta (1, 2), Claire Baffaut (3), Stephen H. Anderson (1) and Shibu Jose (2) ; 1. 302 ABNR Bldg., Dept. of Soil, Environ. and Atmos. Sciences, University of Missouri, Columbia, MO 65211. 2. 203 ABNR Bldg., The Center for Agroforestry, University of Missouri, Columbia, MO 65211. 3. USDA-ARS Cropping Systems and Water Quality Research Unit, 241 Ag. Eng. Bldg., University of Missouri, Columbia, MO 65211.Includes bibliographical references
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