Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

174,276 Full-Text Articles 214,265 Authors 82,890,336 Downloads 343 Institutions

All Articles in Engineering

Faceted Search

174,276 full-text articles. Page 5502 of 5510.

Technical Note: Hydraulic Property Determination Of Denitrifying Bioreactor Fill Media, Laura E. Christianson, Adrià Castelló, Reid D. Christianson, Matthew J. Helmers, Alok Bhandari 2010 Iowa State University

Technical Note: Hydraulic Property Determination Of Denitrifying Bioreactor Fill Media, Laura E. Christianson, Adrià Castelló, Reid D. Christianson, Matthew J. Helmers, Alok Bhandari

Agricultural and Biosystems Engineering Publications

Denitrification bioreactors are one of the newest options for nitrate removal in agricultural drainage waters. Optimization of denitrification bioreactor design requires the ability to identify concrete values for the hydraulic properties of bioreactor fill media. Hydraulic properties, chiefly saturated hydraulic conductivity but also porosity and particle size, are not known for many types of possible bioreactor media though they have a significant impact upon bioreactor design and performance. This work was undertaken to more fully quantify the hydraulic properties of the major type of fill media used in Iowa denitrification bioreactors through a series of porosity, hydraulic conductivity, and particle ...


Real-Time Pressure And Flow Dynamics Due To Boom Section And Individual Nozzle Control On Agricultural Sprayers, Ajay Sharda, John P. Fulton, Timothy P. McDonald, Wesley C. Zech, Matthew J. Darr, Christian J. Brodbeck 2010 Auburn University

Real-Time Pressure And Flow Dynamics Due To Boom Section And Individual Nozzle Control On Agricultural Sprayers, Ajay Sharda, John P. Fulton, Timothy P. Mcdonald, Wesley C. Zech, Matthew J. Darr, Christian J. Brodbeck

Agricultural and Biosystems Engineering Publications

Most modern spray controllers when coupled with a differential global positioning system (DGPS) receiver can provide automatic section or swath (boom section or nozzle) control capabilities that minimize overlap and application into undesirable areas. This technology can improve application accuracy of pesticides and fertilizers, thereby reducing the number of inputs while promoting environmental stewardship. However, dynamic system response for sprayer boom operation, which includes cycling or using auto-swath technology, has not been investigated. Therefore, a study was conducted to develop a methodology and subsequently perform experiments to evaluate tip pressure and system flow variations on a typical agricultural sprayer equipped ...


Optimal Coverage Path Planning For Arable Farming On 2d Surfaces, Jian Jin, Lie Tang 2010 Iowa State University

Optimal Coverage Path Planning For Arable Farming On 2d Surfaces, Jian Jin, Lie Tang

Agricultural and Biosystems Engineering Publications

With the rapid adoption of automatic guidance systems in agriculture, automated path planning has great potential to further optimize field operations. Field operations should be done in a manner that minimizes time and travel over field surfaces and should be coordinated with specific field operation requirements, machine characteristics, and topographical features of arable lands. To reach this goal, an intelligent coverage path planning algorithm is the key. To determine the full coverage pattern of a given field by using boustrophedon paths, it is necessary to know whether to and how to decompose a field into sub-regions and how to determine ...


Soil Loading Effects Of Planter Depth-Gauge Wheels On Early Corn Growth, H. Mark Hanna, Brian L. Steward, Landon Aldinger 2010 Iowa State University

Soil Loading Effects Of Planter Depth-Gauge Wheels On Early Corn Growth, H. Mark Hanna, Brian L. Steward, Landon Aldinger

Agricultural and Biosystems Engineering Publications

Final soil manipulation before seed germination occurs during the planting operation. Contact force of depth-gauge wheels adjacent to the seed opener potentially alters the environment for corn seed germination and early plant growth. A field experiment was conducted measuring seed spacing, spacing variability, seed depth, emergence rate, plant dry matter, final stand, crop growth stage, and extended leaf height with different soil contact loads [light, 180 to 490 N (40 to 110 lb); medium, 490 to 890 N (110 to 200 lb); and heavy, over 890 N (200 lb)] and a range of three soil moistures (dry, moist, wet). A ...


Using Spatial Uncertainty Of Prior Measurements To Design Adaptive Sampling Of Elevation Data, Samsuzana Abd Aziz, Brian L. Steward, Manoj Karkee 2010 Universiti Putra Malaysia

Using Spatial Uncertainty Of Prior Measurements To Design Adaptive Sampling Of Elevation Data, Samsuzana Abd Aziz, Brian L. Steward, Manoj Karkee

Agricultural and Biosystems Engineering Publications

Field sampling can be a major expense for planning within-field management in precision agriculture. An efficient sampling strategy should address knowledge gaps, rather than exhaustively collect redundant data. Modification of existing schemes is possible by incorporating prior knowledge of spatial patterns within the field. In this study, spatial uncertainty of prior digital elevation model (DEM) estimates was used to locate adaptive re-survey regions in the field. An agricultural vehicle equipped with RTK-DGPS was driven across a 2.3 ha field area to measure the field elevation in a continuous fashion. A geostatistical simulation technique was used to simulate field DEMs ...


Swine Producer Appraisal Of The Community Assessment Model For Odor Dispersion (Cam), John C. Tyndall, Jay D. Harmon, Steven J. Hoff 2010 Iowa State University

Swine Producer Appraisal Of The Community Assessment Model For Odor Dispersion (Cam), John C. Tyndall, Jay D. Harmon, Steven J. Hoff

Agricultural and Biosystems Engineering Publications

The community assessment model (CAM) for odor dispersion is a tool to assist in the siting of swine production facilities. CAM considers the size and type of a swine production system, local historical weather conditions, and odor control implementation. It predicts the number of hours of exposure to various levels of odor, by month, for each receptor in a given community. A follow-up survey of all CAM users since 2005 was conducted. The survey was designed to provide: 1) formative feedback for programming adjustments to improve Extension efficiency, usability, and reduce costs; and 2) summative feedback used to provide an ...


Lab-Scale Assessment Of Gaseous Emissions From Laying-Hen Manure Storage As Affected By Physical And Environmental Factors, Hong Li, Hongwei Xin 2010 Iowa State University

Lab-Scale Assessment Of Gaseous Emissions From Laying-Hen Manure Storage As Affected By Physical And Environmental Factors, Hong Li, Hongwei Xin

Agricultural and Biosystems Engineering Publications

Manure-belt (MB) and high-rise (HR) laying-hen houses are the two predominant housing types in the U.S. Compared with HR houses, MB houses have better indoor air quality and lower aerial emissions as a result of frequent (every 1 to 4 d) manure removal from the hen houses into separate manure storage. However, emissions from on-farm manure storage are integral parts of the whole-farm emissions and need to be quantified. This series of lab-scale studies assesses emission rates (ER) of ammonia (NH3) and greenhouse gases (CH4, CO2, and N2O) from stored laying-hen manure as affected by the following physical and ...


Livestock Grazing And Vegetative Filter Strip Buffer Effects On Runoff Sediment, Nitrate, And Phosphorus Losses, David F. Webber, Steven K. Mickelson, Syed I. Ahmed, James R. Russell, Wendy J. Powers, Richard C. Schultz, John Kovar 2010 Iowa State University

Livestock Grazing And Vegetative Filter Strip Buffer Effects On Runoff Sediment, Nitrate, And Phosphorus Losses, David F. Webber, Steven K. Mickelson, Syed I. Ahmed, James R. Russell, Wendy J. Powers, Richard C. Schultz, John Kovar

Agricultural and Biosystems Engineering Publications

Livestock grazing in the Midwestern United States can result in significant levels of runoff sediment and nutrient losses to surface water resources. Some of these contaminants can increase stream eutrophication and are suspected of contributing to hypoxic conditions in the Gulf of Mexico. This research quantified effects of livestock grazing management practices and vegetative filter strip buffers on runoff depth and mass losses of total solids, nitrate-nitrogen (NO3-N), and ortho-phosphorus (PO4-P) under natural hydrologic conditions. Runoff data were collected from 12 rainfall events during 2001 to 2003 at an Iowa State University research farm in central ...


Characterization Of Two Types Of Covered Creep Boxes For Piglet Usage And Piglet Performance In A Naturally Ventilated Swine Farrowing Building, Zhao Bing Gu, Hongwei Xin, Chaoyuan Wang, Zhengxiang Shi, Wei Cao, Zuohua Liu, Baoming Li 2010 Chongqing Academy of Animal Sciences

Characterization Of Two Types Of Covered Creep Boxes For Piglet Usage And Piglet Performance In A Naturally Ventilated Swine Farrowing Building, Zhao Bing Gu, Hongwei Xin, Chaoyuan Wang, Zhengxiang Shi, Wei Cao, Zuohua Liu, Baoming Li

Agricultural and Biosystems Engineering Publications

This study investigates two types of covered piglet creep boxes in a naturally ventilated swine farrowing building with regards to air quality (ammonia and carbon dioxide levels), piglet usage of the box, and piglet health and performance. The covered creep boxes featured either double plastic curtains along the entire width of the box (designated as the DC box) or an arc-shaped access opening occupying about one-third of the box width (designated as the AO box). The study was conducted with 12 farrowing crates, six per box regimen, during wintertime. Continuous, 24-h video observations of the piglet behaviors were made at ...


Studies Of Hydrophobic Organic Pollutant Interactions With Cyclodextrin: Implication For Groundwater Remediation, Heng Gao 2010 Louisiana State University and Agricultural and Mechanical College

Studies Of Hydrophobic Organic Pollutant Interactions With Cyclodextrin: Implication For Groundwater Remediation, Heng Gao

LSU Doctoral Dissertations

Henry’s Law constants of several common, subsurface hydrophobic organic pollutants (HOPs) including trichloroethylene (TCE), perchloroethylene (PCE) and benzene, toluene, ethylbenzene and o-xylene (BTEX), were measured over a range of temperatures (35, 45, 55 and 65°C) and cyclodextrin (CD) concentrations (0, 10, 20, 50 and 100 g L-1). In aqueous CD solutions, Henry’s constant values decrease by a power law relationship with increasing CD concentration due to an apparent solubility enhancement caused by HOP partitioning to the hydrophobic cavity of CD molecules. The temperature dependence of air-water partitioning under the influence of CD was well described by the ...


Study Of Microstructure Effect On The Thermal Properties Of Yttria-Stabilized-Zirconia Thermal Barrier Coatings Made By Atmospheric Plasma Spray And Pressing Machine, Monica Bohorquez de Silva 2010 Louisiana State University and Agricultural and Mechanical College

Study Of Microstructure Effect On The Thermal Properties Of Yttria-Stabilized-Zirconia Thermal Barrier Coatings Made By Atmospheric Plasma Spray And Pressing Machine, Monica Bohorquez De Silva

LSU Doctoral Dissertations

Thermal barrier coatings (TBCs) are used in gas turbine engines to achieve a higher working temperature and thus lead to better efficiency. Yttria-Stabilized-Zirconia (YSZ), a material with low thermal conductivity, is commonly used as the top coat layer to provide the thermal barrier effect. In this dissertation the thermo-physical properties of a variety of TBCs samples made out of different fabrication techniques were investigated and compared. The first set of samples was fabricated using a pressing machine device to fabricate 0.5 inch diameter disk shaped YSZ-Al2O3 samples. The YSZ-Al2O3 powder mixture was made of 0, 1, 2, 3, 4 ...


Model-Based Nonlinear Control Of Active Tilting-Pad Bearings, An Wu 2010 Louisiana State University and Agricultural and Mechanical College

Model-Based Nonlinear Control Of Active Tilting-Pad Bearings, An Wu

LSU Doctoral Dissertations

A promising mechanical bearing candidate for active operation is the tilting-pad bearing. The proposed active tilting-pad bearing has linear actuators that radially translate each pad. The use of feedback control in determining the actuator forces allows for the automatic, continuous adjustment of the pad position during the operation of the rotating machine. In the first part of the dissertation, we develop a nonlinear dynamic model of the active bearing system. The hydrodynamic force produced by the fluid film is modeled as a nonlinear, squeeze-film damper plus repellent spring. A model-based nonlinear controller is then designed to exponentially regulate the rotor ...


Hydrodynamic Modeling Of San Elijo Lagoon, California, Mary Elizabeth nee Friedmann Bourgoyne 2010 Louisiana State University and Agricultural and Mechanical College

Hydrodynamic Modeling Of San Elijo Lagoon, California, Mary Elizabeth Nee Friedmann Bourgoyne

LSU Master's Theses

Decisions on where to concentrate management efforts need to be guided by an ability to accurately simulate and predict physical and ecological changes. Many restoration projects experience difficulties due to a lack of understanding of the ecological response and evolution of wetland systems (Goodwin et al., 2001). There are several approaches that can be taken in analyzing a system. The appropriate selection should be based on the available data, the spatial scale of the wetland, and the physical processes governing the system (Goodwin and Kamman, 2001). Predictive tools are essential for good long-term management (Goodwin et al., 2001). The objective ...


Fabrication, Characterization, Modeling And Testing Of A Nanostructured Bulk Thermoelectric Cooler, Dinesh Pinisetty 2010 Louisiana State University and Agricultural and Mechanical College

Fabrication, Characterization, Modeling And Testing Of A Nanostructured Bulk Thermoelectric Cooler, Dinesh Pinisetty

LSU Doctoral Dissertations

New generation micro/nano devices are emerging to monitor, control and act on living systems. Particularly, in the field of cryobiology, there is a need to monitor and control temperature at the cellular level. An important step towards achieving this aim is to fabricate a novel bulk nanostructured thermoelectric cooler (TEC). As a first step towards achieving efficient localized control of temperature in biological systems, Bismuth-telluride (Bi2Te3) and Antimony-Telluride (Sb2Te3) arrays of nanowires and nanotubes were fabricated, characterized and modeled. A thermal conductivity model originally developed by Dames and Chen for superlattice nanowires was extended to nanotubes. Based on this ...


Operational And Safety Assessment Of Joint And Conventional Lane Merge Configurations For Freeway Work Zones, Pradeep Rayaprolu 2010 Louisiana State University and Agricultural and Mechanical College

Operational And Safety Assessment Of Joint And Conventional Lane Merge Configurations For Freeway Work Zones, Pradeep Rayaprolu

LSU Master's Theses

Inefficient operation of traffic at work zone areas typically leads to increase in travel time delays, queue length, fuel consumption, number of forced merges, and roadway accidents. In order to improve the operational efficiency of work zones, research on freeway work zones constantly seeks to develop different lane merge control strategies, in addition to the conventional lane merge configuration, recommended by the Manual on Uniform Traffic Control Devices. This study evaluates the operational efficiency and safety benefits of a newly proposed configuration, joint lane merge (JLM), and compare its performance with the conventional lane merge (CLM) configuration. A simulation model ...


Influence Of Unstable Soil Movement On Pile-Founded Concrete Floodwalls And A Resulting Design Methodology, Richard James Varuso 2010 Louisiana State University and Agricultural and Mechanical College

Influence Of Unstable Soil Movement On Pile-Founded Concrete Floodwalls And A Resulting Design Methodology, Richard James Varuso

LSU Doctoral Dissertations

Efforts are underway in the New Orleans area to raise the elevations of its levee system to combat the effects of hurricane storm surge. When complete, the majority of the system will be comprised of a combination of levees, sheet pile I-Walls, floodgates, and pile-supported concrete floodwalls, commonly referred to as T-Walls. Given the magnitude of the hydrostatic forces associated with storm surge, global instability is failure mechanism that must be considered in the design of T-Walls. In the past, it was assumed that these forces would be resisted by the T-Wall’s sheet pile cut-off wall. Recent literature review ...


Macroinstability And Perturbation In Turbulent Stirred Tank Flows, Somnath Roy 2010 Louisiana State University and Agricultural and Mechanical College

Macroinstability And Perturbation In Turbulent Stirred Tank Flows, Somnath Roy

LSU Doctoral Dissertations

Impeller stirred tank reactors (STRs) are commonly used in the chemical processing industries for a variety of mixing and blending technologies. In this research, a numerical study of flow and mixing inside turbulently agitated STRs are carried out. An immersed boundary method (IBM) is utilized to represent moving impeller geometries in the background of multi-block structured curvilinear fluid. The IBM This curvilinear-IBM methodology is further combined with the large eddy simulation (LES) technique to address the issue of modeling unsteady turbulent flows in the STR. Verification of the combined IBM-LES implementation strategy in curvilinear coordinates is done through comparisons with ...


Value-Added Processing Of Rice And Rice By-Products, Rebecca C. Schramm 2010 Louisiana State University and Agricultural and Mechanical College

Value-Added Processing Of Rice And Rice By-Products, Rebecca C. Schramm

LSU Doctoral Dissertations

World competition has encouraged United States rice farmers and rice mills to be efficient in farming and production practices. Efforts to augment economic competitiveness include development of new varieties, improvements in milling practices, and identification of uses for rice products and by-products. The research detailed in this dissertation adds to the body of knowledge in milling practices and identification of uses for rice bran. To improve the prediction of milled rice quality at industrial scale, correlations for milling quality among laboratory, pilot, and industrial scale mills were identified for Clearfield 161. Final industrial product whiteness was ten points higher than ...


Identifying And Quantifying Factors Affecting Traffic Crash Severity In Louisiana, Hong Zhang 2010 Louisiana State University and Agricultural and Mechanical College

Identifying And Quantifying Factors Affecting Traffic Crash Severity In Louisiana, Hong Zhang

LSU Doctoral Dissertations

This study was conducted to identify and quantify the factors affecting highway crash severity in Louisiana. Three candidate models were fit to the crash data to compare their performance and the Ordered Mixed Logit (OML) model was selected as the crash severity prediction model of choice. The factors contributing to crash severity identified by the OML model are: age and gender of the driver, vehicle speed, whether alcohol played a role in the crash, whether seatbelts were used, whether the driver was ejected from the vehicle, whether the crash was a head-on collision, whether an airbag was deployed, and whether ...


Degradation Behavior Of Shape Memory Polymer Due To Water And Diesel Fuel, Mohammad Nazmul Hasan Nahid 2010 Louisiana State University and Agricultural and Mechanical College

Degradation Behavior Of Shape Memory Polymer Due To Water And Diesel Fuel, Mohammad Nazmul Hasan Nahid

LSU Master's Theses

Shape memory polymers (SMP) are smart materials, which have the ability to memorize the original or permanent shape. Owing to this characteristic SMP can be used as a sensor, a transplant, as well as structural materials in wide range of applications. Despite its importance, its degradation behavior is still not completely known; and only a limited amount of work has been reported in the literature. In this thesis, the experiments have been carried out to evaluate the degradation behavior of Veriflex- SMP (industry supplied SMP samples) upon exposure to two different types of liquids; water and diesel fuel separately. It ...


Digital Commons powered by bepress