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Biomedical Engineering and Bioengineering Commons

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1997

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Full-Text Articles in Biomedical Engineering and Bioengineering

Implant Having Reduced Generation Of Wear Particulates, David A. Pienkowski Dec 1997

Implant Having Reduced Generation Of Wear Particulates, David A. Pienkowski

Biomedical Engineering Faculty Patents

A method is provided for reducing the amount of wear particulates generated by a total joint orthopaedic implant. The implant consists of two matched articulating components. The method includes the steps of placing the total joint orthopaedic implant in a fluid bath and articulating the implant in the fluid bath for at least 1,000 cycles. The articulation may be performed in three stages. In the first, the implant is articulated under a load of substantially 0.1-500 Newtons with sliding speeds of substantially 0.01-0.5 meters per second. During a second stage the articulation takes place under a load of substantially 200-2,500 …


Sediment Movement Within A Strip Intercropping System, John E. Gilley, L. A. Kramer, R. M. Cruse, A. Hull Nov 1997

Sediment Movement Within A Strip Intercropping System, John E. Gilley, L. A. Kramer, R. M. Cruse, A. Hull

Biological Systems Engineering: Papers and Publications

This study was conducted to identify sediment movement within a strip intercropping system in southwestern Iowa during the third year of a three-year crop rotation. Soil loss, resulting from the application of simulated rainfall to a Monona silt loam soil, was measured from individual corn (Zea mays L.), soybean (Glycine max (L.) Merr), and winter wheat (Triticum aestivum L.) strips, and from multiple strips which included all three crops. Because of the crop rotation and residue management procedures, used at the study site, a substantial amount of surface cover and vegetative mass was present on each of …


Process For Producing Biodiesel Fuel With Reduced Viscosity And A Cloud Point Below Thirty-Two (32) Degrees Fahrenheit , Hossein Noureddini Oct 1997

Process For Producing Biodiesel Fuel With Reduced Viscosity And A Cloud Point Below Thirty-Two (32) Degrees Fahrenheit , Hossein Noureddini

Papers in Biomaterials

Triglycerides are reacted in a liquid phase reaction with methanol and a homogeneous basic catalyst. The reaction yields a spatially separated two phase result with an upper located non-polar phase consisting principally of non-polar methyl esters and a lower located phase consisting principally of glycerol and residual methyl esters. The glycerol phase is passed through a strong cationic ion exchanger to remove anions, resulting in a neutral product which is flashed to remove methanol and which is reacted with isobutylene in the presence of a strong acid catalyst to produce glycerol ethers. The glycerol ethers are then added back to …


Runoff, Erosion, And Soil Quality Characteristics Of A Former Conservation Reserve Program Site In Southwestern Oklahoma, John E. Gilley, John W. Doran, Thanh H. Dao Sep 1997

Runoff, Erosion, And Soil Quality Characteristics Of A Former Conservation Reserve Program Site In Southwestern Oklahoma, John E. Gilley, John W. Doran, Thanh H. Dao

Biological Systems Engineering: Papers and Publications

This study was conducted to measure runoff, erosion, and soil quality characteristics of a site in southwestern Oklahoma the first year following conversion from the Conservation Reserve Program (CRP). Treatments included undisturbed CRP, Old World bluestem (Bothriochlora ischaemum L.), no-till wheat (Triticum aestivum L.) and conservation-till wheat. Significant differences in surface cover were found between each of the experimental treatments, with values ranging from 100% on the undisturbed CRP site to 42% for the conservation-till treatment. No significant difference in runoff was found among the various experimental treatments. The Old World bluestem and winter wheat treatments had only …


Testing Of A Water Loss Distribution Model For Moving Sprinkler Systems, Allen L. Thompson, Derrel L. Martin, John M. Norman, Judy A. Tolk, James R. Gilley, Arlan D. Schneider Sep 1997

Testing Of A Water Loss Distribution Model For Moving Sprinkler Systems, Allen L. Thompson, Derrel L. Martin, John M. Norman, Judy A. Tolk, James R. Gilley, Arlan D. Schneider

Biological Systems Engineering: Papers and Publications

Field water balance measurements using monolithic lysimeters were used in validating the Cupid-DPE model for predicting water loss partitioning during sprinkler irrigation from a moving lateral system fitted with impact sprinklers and spray nozzles. The model combines equations governing water droplet evaporation and droplet ballistics with a comprehensive plant-environment energy balance model. Comparisons indicate good agreement between measured and modeled transpiration, and the measured and modeled soil evaporation during the day of irrigation. Total predicted evapotranspiration during the day of irrigation was greater than measured totals using the monolithic lysimeters. However, part of this difference was because the lysimeters could …


Water Transport And The Distribution Of Aquaporin-1 In Pulmonary Air Spaces, Richard M. Effros, C. Darin, Elizabeth R. Jacobs, R. A. Rogers, Gary S. Krenz, E. E. Schneeberger Sep 1997

Water Transport And The Distribution Of Aquaporin-1 In Pulmonary Air Spaces, Richard M. Effros, C. Darin, Elizabeth R. Jacobs, R. A. Rogers, Gary S. Krenz, E. E. Schneeberger

Biomedical Engineering Faculty Research and Publications

Recent evidence suggests that water transport between the pulmonary vasculature and air spaces can be inhibited by HgCl2, an agent that inhibits water channels (aquaporin-1 and -5) of cell membranes. In the present study of isolated rat lungs, clearances of labeled (3HOH) and unlabeled water were compared after instillation of hypotonic or hypertonic solutions into the air spaces or injection of a hypotonic bolus into the pulmonary artery. The clearance of 3HOH between the air spaces and perfusate after intratracheal instillation and from the vasculature to the tissues after pulmonary arterial injections was invariably greater …


Interferon Gamma (Ifn-Gamma) Is Necessary For The Genesis Of Acetylcholine Receptor-Induced Clinical Experimental Autoimmune Myasthenia Gravis In Mice., Balaji Balasa, Caishu Deng, Jae Lee, Linda M. Bradley, Dyanna K. Dalton, Premkumar Christadoss, Nora Sarvetnick Aug 1997

Interferon Gamma (Ifn-Gamma) Is Necessary For The Genesis Of Acetylcholine Receptor-Induced Clinical Experimental Autoimmune Myasthenia Gravis In Mice., Balaji Balasa, Caishu Deng, Jae Lee, Linda M. Bradley, Dyanna K. Dalton, Premkumar Christadoss, Nora Sarvetnick

Journal Articles: Regenerative Medicine

Experimental autoimmune myasthenia gravis (EAMG) is an animal model of human myasthenia gravis (MG). In mice, EAMG is induced by immunization with Torpedo californica acetylcholine receptor (AChR) in complete Freund's adjuvant (CFA). However, the role of cytokines in the pathogenesis of EAMG is not clear. Because EAMG is an antibody-mediated disease, it is of the prevailing notion that Th2 but not Th1 cytokines play a role in the pathogenesis of this disease. To test the hypothesis that the Th1 cytokine, interferon (IFN)-gamma, plays a role in the development of EAMG, we immunized IFN-gamma knockout (IFN-gko) (-/-) mice and wild-type (WT) …


Model Of Flexural Fatigue Damage Accumulation For Cortical Bone, L. V. Griffin, J. C. Gibeling, R. B. Martin, V. A. Gibson, S. M. Stover Jul 1997

Model Of Flexural Fatigue Damage Accumulation For Cortical Bone, L. V. Griffin, J. C. Gibeling, R. B. Martin, V. A. Gibson, S. M. Stover

Biomedical Engineering

Analytical models that predict modulus degradation in cortical bone subjected to uniaxial fatigue loading in tension and compression are presented. On the basis of experimental observations, damage was modeled as self-limiting for tension but not for compression. These mechanistic uniaxial damage models were then developed into a model for flexural fatigue of cortical bone based on laminated beam theory. The unknown coefficients in the uniaxial damage models were obtained by successfully fitting the resulting equations to uniaxial fatigue data from the literature on human cortical bone in tension and compression. Then, the predictions of the flexural model for the behavior …


Laparoscopic Assisted Fusion Of The Lumbosacral Spine: A Biomechanical And Histologic Analysis Of The Open Versus Laparoscopic Technique In An Animal Model, Lee H. Riley Iii, Jason C. Eck, Hiryuki Yoshida, Jeffrey M. Toth, Nguyen Cahn, Tae Hong Lim, Linda M. Mcgrady Jun 1997

Laparoscopic Assisted Fusion Of The Lumbosacral Spine: A Biomechanical And Histologic Analysis Of The Open Versus Laparoscopic Technique In An Animal Model, Lee H. Riley Iii, Jason C. Eck, Hiryuki Yoshida, Jeffrey M. Toth, Nguyen Cahn, Tae Hong Lim, Linda M. Mcgrady

Biomedical Engineering Faculty Research and Publications

Study Design. An animal model for laparoscopic lumbosacral fusion.

Objectives. To compare the biomechanical and histologic results of open to laparoscopic lumbosacral discectomy and fusion in an animal model.

Background Data. Early clinical reports of laparoscopic lumbosacral fusions are encouraging, but animal experiments have not been reported.

Methods. Ten pigs (50-80 kg) were divided into two groups. Group 1 underwent an open anterior lumbosacral discectomy and fusion at L7-S1 using autologous bone graft and a titanium MOSS (DePuy Motech) cage. Group 2 was identical to Group 1 except that a laparoscopic technique was used. The animals were killed at 3 …


Experimental Spinal Fusion With Recombinant Human Bone Morphogenetic Protein-2 Without Decortication Of Osseous Elements, Harvinder Sandhu, Linda E.A. Kanim, Jeffrey M. Toth, J. Michael Kabo, David Liu, Rick B. Delamarter, Edgar G. Dawson Jun 1997

Experimental Spinal Fusion With Recombinant Human Bone Morphogenetic Protein-2 Without Decortication Of Osseous Elements, Harvinder Sandhu, Linda E.A. Kanim, Jeffrey M. Toth, J. Michael Kabo, David Liu, Rick B. Delamarter, Edgar G. Dawson

Biomedical Engineering Faculty Research and Publications

Study Design. L4-L5 intertransverse process fusions were produced with 58 μg, 230 μg, or 920 μg of recombinant human bone morphogenetic protein-2 in 20 dogs. Eleven had traditional decortication of posterior elements before insertion of the implant. Nine were left undecorticated. All animals were evaluated 3 months after surgery.

Objectives. To determine whether decortication is a prerequisite for successful fusion in the presence of osteoinductive proteins such as bone morphogenetic protein-2.

Summary of Background Data. Recombinant osteoinductive proteins can induce de novo bone in ectopic soft-tissue sites in the absence of bone marrow elements. Traditional methods for achieving spinal fusion …


Local Delivery Of Interleukin 4 By Retrovirus-Transduced T Lymphocytes Ameliorates Experimental Autoimmune Encephalomyelitis., Michael K. Shaw, James B. Lorens, Archana Dhawan, Richard Dalcanto, Harley Y. Tse, Alyssa B. Tran, Colleen Bonpane, Shanti L. Eswaran, Stefan Brocke, Nora Sarvetnick, Lawrence Steinman, Garry P. Nolan, C. Garrison Fathman May 1997

Local Delivery Of Interleukin 4 By Retrovirus-Transduced T Lymphocytes Ameliorates Experimental Autoimmune Encephalomyelitis., Michael K. Shaw, James B. Lorens, Archana Dhawan, Richard Dalcanto, Harley Y. Tse, Alyssa B. Tran, Colleen Bonpane, Shanti L. Eswaran, Stefan Brocke, Nora Sarvetnick, Lawrence Steinman, Garry P. Nolan, C. Garrison Fathman

Journal Articles: Regenerative Medicine

Experimental autoimmune encephalomyelitis (EAE) is an inflammatory autoimmune disease of the central nervous system which serves as a model for the human disease multiple sclerosis. We demonstrate here that encephalitogenic T cells, transduced with a retroviral gene, construct to express interleukin 4, and can delay the onset and reduce the severity of EAE when adoptively transferred to myelin basic protein-immunized mice. Thus, T lymphocytes transduced with retroviral vectors can deliver "regulatory cytokines" in a site-specific manner and may represent a viable therapeutic strategy for the treatment of autoimmune disease.


Tillage Effects On Soil Erosion Potential And Soil Quality Of A Former Conservation Reserve Program Site, John E. Gilley, J. W. Doran May 1997

Tillage Effects On Soil Erosion Potential And Soil Quality Of A Former Conservation Reserve Program Site, John E. Gilley, J. W. Doran

Biological Systems Engineering: Papers and Publications

This study was conducted to determine the effects of tillage on soil erosion potential and soil quality characteristics of a former Conservation Research Program (CRP) site. Following tillage, the study area in northern Mississippi was maintained in a fallow condition for nine months. Soil loss from simulated rainfall events was minimal on recently tilled plots and an adjoining, undisturbed CRP area. In contrast, soil loss from the former CRP site which had been tilled nine months previously was similar to values obtained before the CRP program when the area had been cropped for several years. Tillage and over-winter fallowing caused …


Monoclonal Antibody Assay And Kit For Detecting Metal Cations In Body Fluids (Continuation), Randall R. Carlson, Jay S. Stout, Dwane E. Wylie, Fred W. Wagner, Malcolm Riddell Apr 1997

Monoclonal Antibody Assay And Kit For Detecting Metal Cations In Body Fluids (Continuation), Randall R. Carlson, Jay S. Stout, Dwane E. Wylie, Fred W. Wagner, Malcolm Riddell

Biological Process Development Facility: Staff Publications

The invention provides method and kits for detecting a metallic cation in a sample of a body fluid. The preferred method and kits include the use of at least two different types of antibodies having different specificities. In the preferred method, the sample of body fluid can be contacted with an effective amount of a capture antibody specific for a naturally occurring polypeptide that can bind the metallic cation to form a first antigen-antibody complex. An effective amount of an antibody specific for an epitope on a metallic cation-naturally occurring polypeptide complex or an antibody specific for a metallic cation …


Glycerolysis Of Fats And Methyl Esters., Hossein Noureddini, V Medikonduru Apr 1997

Glycerolysis Of Fats And Methyl Esters., Hossein Noureddini, V Medikonduru

Papers in Biomaterials

The glycerolysis of methyl esters and triglycerides with crude glycerol. a coproduct from the transesterification of triglycerides, was studied. Three procedures were followed ior this conversion. The first procedure was a one-step glycerolysis with methyl esters. The second procedure was a two-step process. This proced~~irnev olved an initial partial glycerolysis with methyl esters, followed by fat glycerolysis. The third procedure u,as a simultaneous glycerolysis n,ith methyl esters and triglycerides. In the glycerolysis with methyl esters, the removal of methanol is vital to the production of mono- and diglycerides. Methanol was removed either by drawing vacuum on the reactor or by …


Generic, Geometric Finite Element Analysis Of The Transtibial Residual Limb And Prosthetic Socket, Barbara Silver-Thorn, Dudley S. Childress Apr 1997

Generic, Geometric Finite Element Analysis Of The Transtibial Residual Limb And Prosthetic Socket, Barbara Silver-Thorn, Dudley S. Childress

Biomedical Engineering Faculty Research and Publications

Finite element analysis was used to investigate the stress distribution between the residual limb and prosthetic socket of persons with transtibial amputation (TTA). The purpose of this study was to develop a tool to provide a quantitative estimate of prosthetic interface pressures to improve our understanding of residual limb/prosthetic socket biomechanics and prosthetic fit. FE models of the residual limb and prosthetic socket were created. In contrast to previous FE models of the prosthetic socket/residual limb system, these models were not based on the geometry of a particular individual, but instead were based on a generic, geometric approximation of the …


Slice Location Dependence Of Aortic Regurgitation Measurements With Mr Phase Velocity Mapping, George P. Chatzimavroudis, Peter G. Walker, John N. Oshinski, Robert H. Franch, Roderic I. Pettigrew, Ajit P. Yoganathan Apr 1997

Slice Location Dependence Of Aortic Regurgitation Measurements With Mr Phase Velocity Mapping, George P. Chatzimavroudis, Peter G. Walker, John N. Oshinski, Robert H. Franch, Roderic I. Pettigrew, Ajit P. Yoganathan

Chemical & Biomedical Engineering Faculty Publications

Although several methods have been used clinically to assess aortic regurgitation (AR), there is no “gold standard” for regurgitant volume measurement. Magnetic resonance phase velocity mapping (PVM) can be used for noninvasive blood flow measurements. To evaluate the accuracy of PVM in quantifying AR with a single imaging slice in the ascending aorta, in vitro experiments were performed by using a compliant aortic model. Attention was focused on determining the slice location that provided the best results. The most accurate measurements were taken between the aortic valve annulus and the coronary ostia where the measured (Y) and actual …


Residual Strength Of Equine Bone Is Not Reduced By Intense Fatigue Loading: Implications For Stress Fracture, R. B. Martin, V. A. Gibson, S. M. Stover, J. C. Gibeling, L. V. Griffin Feb 1997

Residual Strength Of Equine Bone Is Not Reduced By Intense Fatigue Loading: Implications For Stress Fracture, R. B. Martin, V. A. Gibson, S. M. Stover, J. C. Gibeling, L. V. Griffin

Biomedical Engineering

Fatigue or stress fractures are an important clinical problem in humans as well as racehorses. An important question in this context is, when a bone experiences. fa!igue damage ~uring e~treme use, how much is it weakened compared to its original state? Since there are very ltmtted data on thts quesuon and stress fractures are common in racehorses, we sought to determine the effect of fatigue loading on the monotonic l:trength of equine cortical bone. Beams were machined from the dorsal, medial and lateral cortices of the third metacarpal bones of six thoroughbred racehorses. Beams from left and right bones were …


Ifn-Gamma, Igif, And Iddm., Nora Sarvetnick Feb 1997

Ifn-Gamma, Igif, And Iddm., Nora Sarvetnick

Journal Articles: Regenerative Medicine

No abstract provided.


Simulating The Distribution Of Axon Size In Nerves, Robert B. Szlavik, Hubert De Bruin Jan 1997

Simulating The Distribution Of Axon Size In Nerves, Robert B. Szlavik, Hubert De Bruin

Biomedical Engineering

The electrical excitation threshold of a nerve axon is dependent upon the physical properties of the axon membrane as well as the axon diameter. Histological studies have confirmed that peripheral afferent muscle nerves have a characteristic distribution of axon diameters. We approximate a probability density function for this distribution that consists of the summation of several Gaussian functions. A transformation technique is then applied for the random generation of the nerve axon diameters from uniformly distributed random numbers. For the example presented, the resultant distribution of peripheral afferent muscle nerve axon diameters conforms approximately to the characteristic distribution that has …


Corrosion Fatigue Crack Growth Behavior Of Aircraft Materials, Tarun Goswami, D. W. Hoeppner Jan 1997

Corrosion Fatigue Crack Growth Behavior Of Aircraft Materials, Tarun Goswami, D. W. Hoeppner

Biomedical, Industrial & Human Factors Engineering Faculty Publications

The effects of test parameters on the corrosion fatigue crack growth behavior of structural materials have been examined in this paper. Test parameters such as stress ratio, frequency, hold time, temperature, pH level of the media, and other parameters are known to alter the corrosion fatigue crack growth rates in structural materials. Numerous laboratory test variables that affect the crack growth and/or corrosion growth rates, which in an operating environment of an aircraft are not characterized, are reviewed. A summary of such information may help determine the inspection intervals of the new and aged airplanes, perform the inspections, and develop …


Review Of Pit Nucleation, Growth And Pitting Corrosion Fatigue Mechanisms, Tarun Goswami, D. W. Hoeppner Jan 1997

Review Of Pit Nucleation, Growth And Pitting Corrosion Fatigue Mechanisms, Tarun Goswami, D. W. Hoeppner

Biomedical, Industrial & Human Factors Engineering Faculty Publications

This paper presents a review of the state of the art developments in the pitting corrosion fatigue of aircraft structural materials. Mechanisms that govern the nucleation and growth of pitting and corrosion fatigue (CF) are briefly addressed. Some of the developments made in the author's laboratories in proposing the fretting induced pit nucleation and growth mechanisms, analysis of the hidden corrosion constituents in fuselage joints and pitting corrosion fatigue crack growth (PCFCG) model are elucidated. An epistemology of the topic is presented which will be of assistance to the community working in this area.


Fracture Of An Acetabular Component Inserted Without Cement: A Case Report, R T. Trousdale, D J. Berry, Joshua J. Jacobs, Jeremy L. Gilbert Jan 1997

Fracture Of An Acetabular Component Inserted Without Cement: A Case Report, R T. Trousdale, D J. Berry, Joshua J. Jacobs, Jeremy L. Gilbert

Biomedical and Chemical Engineering - All Scholarship

No abstract provided.


Dwell Sensitivity Fatigue Behaviour Of High Temperature Materials, Tarun Goswami, G. R. Halford, D. W. Hoeppner Jan 1997

Dwell Sensitivity Fatigue Behaviour Of High Temperature Materials, Tarun Goswami, G. R. Halford, D. W. Hoeppner

Biomedical, Industrial & Human Factors Engineering Faculty Publications

The dwell sensitivity fatigue behavior of six high temperature materials is examined in this paper: two stainless steels, 304L and 304, two tantalum alloys, Τ- Ι 11 and ASTAR 811C, pure nickel Ni 201 and a single crystal nickel-base superalloy, PWA 1480. The stainless steel alloys were found to be tensile dwell sensitive; however, a saturation in dwell sensitivity was found with the increase in strain range for all materials examined. At lower strain ranges the dwell cycles were producing lower lives than at higher strains, as found in the case of AISI SS 304 and two tantalum based alloys, …


A New Model Of High Temperature Low Cycle Fatigue Life Prediction - Applicability With Low Alloy Steels, Tarun Goswami Jan 1997

A New Model Of High Temperature Low Cycle Fatigue Life Prediction - Applicability With Low Alloy Steels, Tarun Goswami

Biomedical, Industrial & Human Factors Engineering Faculty Publications

Creep-fatigue data on low alloy steels were collected from National Research Institute for Metals (NRIM) Tokyo, Japan. These data were generated for lCr-Mo-V, 2.25Cr-Mo, and 9Cr-lMo steels under a wide range of test conditions. A new creep-fatigue life prediction method was developed and data compiled were assessed to examine the applicability of the new method. A brief review of the empirically based, phenomenological life prediction methods was presented where no method was found to be applicable universally to all the creep-fatigue data. The new model was developed within the viscosity concepts, in which the damage parameter was accounted for in …


Irrigation Performance Measures: Efficiency And Uniformity, C. M. Burt, A. J. Clemmens, T. S. Strelkoff, K. H. Solomon, R. D. Bliesner, L. A. Hardy, T. A. Howell, Dean E. Eisenhauer Jan 1997

Irrigation Performance Measures: Efficiency And Uniformity, C. M. Burt, A. J. Clemmens, T. S. Strelkoff, K. H. Solomon, R. D. Bliesner, L. A. Hardy, T. A. Howell, Dean E. Eisenhauer

Biological Systems Engineering: Papers and Publications

It is essential to standardize the definitions and approaches to quantifying various irrigation performance measures. The ASCE Task Committee on Defining Irrigation Efficiency and Uniformity provides a comprehensive examination of various performance indices such as irrigation efficiency, application efficiency, irrigation sagacity, distribution uniformity, and others. Consistency is provided among different irrigation methods and different scales. Clarification of common points of confusion is provided, and methods are proposed whereby the accuracy of numerical values of the performance indicators can be assessed. This issue has two companion papers that provide more detailed information on statistical distribution uniformity and the accuracy of irrigation …


The Nature Of Blacks' Skepticism About Genetic Testing, Dorothy E. Roberts Jan 1997

The Nature Of Blacks' Skepticism About Genetic Testing, Dorothy E. Roberts

All Faculty Scholarship

No abstract provided.


Films From Laboratory-Extracted Sorghum Kafirin, Roberto A. Buffo, Curtis L. Weller, Aristippos Gennadios Jan 1997

Films From Laboratory-Extracted Sorghum Kafirin, Roberto A. Buffo, Curtis L. Weller, Aristippos Gennadios

Biological Systems Engineering: Papers and Publications

There has been increased interest in development of biopolymer films and coatings from protein, polysaccharide, and lipid materials in recent years. The qualities of renewability, degradability, compostability, and edibility make such films particularly appealing for food and nonfood packaging applications. Moreover, wide commercialization of biopolymer films will provide a value-added innovative use for traditional agricultural commodities as sources of film-forming materials. Research findings on production, properties, and potential applications of edible films have been reviewed (Krochta 1992, Conca and Yang 1993, Gontard and Guilbert 1994). Protein films in particular have been discussed in detail by Gennadios et al (1994a) and …


Selected Physical Properties Of Jointed Goatgrass (Aegilops Cylindrica Host.), C. M. Hubbard, Curtis L. Weller, David D. Jones Jan 1997

Selected Physical Properties Of Jointed Goatgrass (Aegilops Cylindrica Host.), C. M. Hubbard, Curtis L. Weller, David D. Jones

Biological Systems Engineering: Papers and Publications

Selected physical properties of jointed goatgrass samples collected in western Nebraska and eastern Colorado were determined. Measured properties were spikelet dimensions (length 10.8 ± 0.35 mm; width 2.59 ± 0.25 mm), particle density (0.761 ± 0.016 g/m3), bulk density (351 ± 26.9 kg/m3), terminal velocity (301 ± 25.9 m/min), angle of repose (26.3 ± 0.286°), internal coefficient of friction (0.494 ± 0.007), and equilibrium moisture contents at 10% RH (6.56 ± 1.03% w.b.), 30% RH (7.43 ± 1.21% w.b.), 50% RH (9.01 ± 0.67% w.b.), 70% RH (11.89 ± 0.61% w.b.), and 90% RH (20.39 ± …


Nutrient, Carbon, And Mass Loss During Composting Of Beef Cattle Feedlot Manure, Bahman Eghball, James F. Power, John E. Gilley, John W. Doran Jan 1997

Nutrient, Carbon, And Mass Loss During Composting Of Beef Cattle Feedlot Manure, Bahman Eghball, James F. Power, John E. Gilley, John W. Doran

Biological Systems Engineering: Papers and Publications

Quantification of nutrient and mass loss during composting is needed to understand the composting process, to implement methods for nutrient conservation, and to reduce potential adverse environmental impact. Beef cattle feedlot manure was composted in a windrow on an open concrete area in 1992, 1993, and 1994 to determine the amounts of nutrient, C, and mass loss during composting. The area was enclosed on all sides with a 0.2 m high metal sheet to direct runoff to a fiberglass tank (4000 L) during rainfall. Nutrients in runoff represented combined runoff and leaching losses. Nutrients, C, and mass loss during composting …


Adsorption And Desorption Of Phosphorus And Nitrogen By Immersed Stalks, John E. Gilley, B. Eghball, David B. Marx Jan 1997

Adsorption And Desorption Of Phosphorus And Nitrogen By Immersed Stalks, John E. Gilley, B. Eghball, David B. Marx

Biological Systems Engineering: Papers and Publications

Adsorption and desorption of phosphorus (P) and nitrogen (N) by stalk residues may influence the concentrations of P and N in runoff. A laboratory study was conducted to measure the effects of P and N constituents in solution on adsorption and desorption of P and N by corn, soybean, and wheat stalk residues. Experimental variables included type of stalk material (corn, soybean, and wheat), inorganic nutrients in solution (PO4-P and NO3-N; PO4-P and NH4-N; NO3-N and NH4-N; and PO4-P, NO3-N, and NH4-N), …