Engineering Commons^™

Humidity Effects On The Determination Of Elastic Properties By Atomic Force Acoustic Microscopy, D.C. Hurley, Joseph A. Turner

Nebraska Center for Materials and Nanoscience: Faculty Publications

We have investigated how ambient humidity can affect quantitative measurements of elastic properties on the nanoscale. Using an emerging technique called atomic force acoustic microscopy (AFAM), two samples were examined: a thin film of fluorosilicate glass and a section of borosilicate glass. When experimental results were analyzed using a simple model of the atomic force microscope cantilever dynamics, values of the tip–sample contact stiffness k* increased approximately linearly with relative humidity. The effect is believed to be due to the presence of a humidity-dependent layer of water on the sample. To account for this, the data analysis model was …

Acuta Enews February 2004, Vol. 33, No. 2

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Fatty Acid Composition And Oxidation Of Lipids In Korean Catfish, K. T. Hwang, J. E. Kim, S. G. Kang, S. T. Jung, H. J. Park, Curtis L. Weller

Department of Agricultural and Biological Systems Engineering: Faculty Publications

This study determined the lipid content and FA composition of muscle and a mixture of muscle and viscera from Korean catfish as well as lipid oxidation and hydrolysis. Lipid content and FA compositions in Korean catfish, which were purchased every month or two during September 1999–July 2000, were analyzed. Lipid oxidation and hydrolysis were determined as PV, thiobarbituric acid value, and FFA in the muscle and the mixture during storage at 2°C for 12 d and –14°C for 9 wk. Lipid contents of the muscle and the mixture were 3.2 (w/w) and 5.4%, respectively. Oleic acid was the most abundant …

A Continuous Process For The Glycerolysis Of Soybean Oil , Hossein Noureddini, D W. Harkey, M R. Gutsman

Papers in Biomaterials

A continuous process for the glycerolysis of soybean oil with pure and crude glycerol, the co-product from the transesterification of soybean oil was investigated in a pilot plant. The process was equipped with a motionless and a high-shear mixer. The experimental studies explored the effects of variations in mixing intensity, temperature, reactant flow rates, and reactant stoichiometry on the formation of MG and DC. The developed process resulted in high conversion of TC to MC. The most favorable conditions were 230°C, 40 mL/min total flow, 25 mm of reaction time, 2.5:1 molar ratio of glycerol/soybean oil, and 3600 rpm for …

Ultrasound Diffusion For Crack Depth Determination In Concrete, S.K. Ramamoorthy, Y. Kane, Joseph A. Turner

Nebraska Center for Materials and Nanoscience: Faculty Publications

The determination of the depth of surface-breaking cracks in concrete specimens using an ultrasound diffusion technique is discussed. Experiments were carried out on precracked concrete specimens of varying crack depths (0%–40% of the specimen thickness). Contact transducers were placed at the specimen surface with source and receiver separated by the crack. Tone-burst excitations over a frequency range of 400–600 kHz were used. At these frequencies, ultrasound is scattered considerably by the heterogeneities in the concrete. In the limit of many scattering events, the evolution of energy may be modeled as a diffusion process. The arrival of the peak diffuse energy …

Jan 2004, Tractor Museum

Lester F. Larsen Tractor Museum: Planning and Development Documents

NE Museum Budget Cuts Selling Farmall H Husker Harvest Days

Bar Clamp Having Ergonomic Handle, M. Susan Hallbeck, Myung-Chul Jung

Department of Mechanical and Materials Engineering: Faculty Publications

The present invention generally relates to a handle assembly for a hand operable bar clamp having a fixed jaw, a movable jaw and a drive for translating the movable jaw towards the fixed jaw. The assembly includes a handgrip and a trigger handle. The handgrip having an elongated rear portion has a generally rounded surface and being contoured to complement the natural transverse curve pf a human palm. The trigger handle is pivotal with respect to the handgrip. The trigger handle included an elongated front portion having a rounded front surface and being contoured to complement the natural palmer curve …

Total Reduced Sulfur Concentrations In The Vicinity Of Beef Cattle Feedlots, Richard K. Koelsch, Bryan L. Woodbury, David E. Stenberg, Daniel N. Miller, Dennis D. Schulte

Department of Agricultural and Biological Systems Engineering: Faculty Publications

A field survey of total reduced sulfur (TRS) concentrations in the vicinity of beef cattle feedlots was conducted to compare field observations against current regulatory thresholds. In addition, environmental factors that may contribute to increased TRS emissions were evaluated. It was observed that TRS levels in the vicinity of beef cattle feedlots are not likely to exceed current regulatory thresholds used by midwestern states. It was further noted that concentration of TRS varies with air temperature and time of day. However, wet feedlot surface conditions and wind speed had almost no impact upon observed concentrations.

Interfaces, Volume 7, Issue 1 - Winter 2004

INTERFACES: Newsletter of the Nebraska Center for Materials and Nanoscience

Facility Focus (I): Multipurpose X-Ray System Zeng Named Guggenheim Fellow Sigma Xi Honors to CMRA Faculty, Staff and Students Best Paper Awards Degree of Doctor Honoris Causa Recent Patents Facility Focus(II): Equipment Upgrade in Electron Microscopy CMRA Welcomes Fereydoon Namavar Research Spotlight: Stephen Ducharme Spinning Continuous Fibers for Nanotechnology

Mapping Surface Polarization In Thin Films Of The Ferroelectric Polymer P(Vdf-Trfe)., Bradley W. Peterson, Stephen Ducharme, Vladimir M. Fridkin, Timothy J. Reece

Stephen Ducharme Publications

Pyroelectric Scanning Microscopy (PSM) has been developed to enable mapping of surface polarization in ferroelectric thin films, in particular the copolymer polyvinylidene fluoride trifluororethylene, or P(VDF-TrFE). The Chynoweth method for dynamically measuring pyroelectric current is employed in conjunction with a micropositioning system to construct two-dimensional images of the film polarization. These images have revealed enhancement of the polarization near the edges of the film below the average coercive field, with the center's polarization increasing thereafter to meet the edge value at saturation.

A Docking Score Function For Estimating Ligand-Protein Interactions: Application To Acetylcholinesterase Inhibition, Jianxin Guo, Margaret M. Hurley, Jeffery B. Wright, Gerald H. Lushington

United States Army: Publications

Acetylcholinesterase (AChE) inhibition is an important research topic because of its wide range of associated health implications. A receptor-specific scoring function was developed herein for predicting binding affinities for human AChE (huAChE) inhibitors. This method entails a statistically trained weighted sum of electrostatic and van der Waals (VDW) interactions between ligands and the receptor residues. Within the 53 ligand training set, a strong correlation was found (R² = 0.89) between computed and experimental inhibition constants. Leave-oneout cross-validation indicated high predictive power (Q² = 0.72), and analysis of a separate 16-compound test set also produced very good correlation with …

Nebraska Summary: S526 New Holland Tl 100a, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

Nebraska Summary: S508 Challenger Mt545b, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

Test 2203: New Holland Ts135a Diesel, Nebraska Tractor Test Lab

Nebraska Tractor Tests

No abstract provided.

Tests 2290 & 2291: Challenger Mt445b Diesel, Nebraska Tractor Test Lab

Nebraska Tractor Tests

No abstract provided.

Biotransformation Of Two-Line Silica-Ferrihydrite By A Dissimilatory Fe(Iii)-Reducing Bacterium: Formation Of Carbonate Green Rust In The Presence Of Phosphate, Ravi K. Kukkadapu, John M. Zachara, James K. Fredrickson, David W. Kennedy

United States Department of Energy: Publications

The reductive biotransformation of two Si-ferrihydrite coprecipitates (1 and 5 mole % Si) by Shewanella putrefaciens, strain CN32, was investigated in 1,4-piperazinediethanesulfonic acid-buffered media (pH ~7) with lactate as the electron donor. Anthraquinone-2,6-disulfonate, an electron shuttle, was present in the media. Experiments were performed without and with PO₄^3- (P) (1 to 20 mmol/L) in media containing 50 mmol/L Fe. Our objectives were to define the combined effects of SiO₄^{4 -} (Si) and P on the bioreducibility and biomineralization of ferrihydrites under anoxic conditions. Iron reduction was measured as a function of time, solids were characterized …

A Cation Exchange Model To Describe Cs+ Sorption At High Ionic Strength In Subsurface Sediments At Hanford Site, Usa, Chongxuan Liu, John M. Zachara, Steven Smith

United States Department of Energy: Publications

A theoretical and experimental study of cation exchange in high ionic strength electrolytes was performed using pristine subsurface sediments from the U.S. Department of Energy Hanford site. These sediments are representative of the site contaminated sediments impacted by release of high level waste (HLW) solutions containing ¹³⁷Cs⁺ in NaNO₃ brine. The binary exchange behavior of Cs⁺–Na⁺, Cs⁺–K⁺, and Na⁺–K⁺ was measured over a range in electrolyte concentration. Vanselow selectivity coefficients (K_v) that were calculated from the experimental data using Pitzer model ion activity …

Endocrine-Disrupting Effects Of Cattle Feedlot Effluent On An Aquatic Sentinel Species, The Fathead Minnow, Edward Orlando, Alan Kolok, Gerry Binzcick, Jennifer Gates, Megan Horton, Christy Lambright, L. Earl Gray, Jr., Ana M. Soto, Louis J. Guilette, Jr.

United States Environmental Protection Agency: Publications

Over the last decade, research has examined the endocrine-disrupting action of various environmental pollutants, including hormones, pharmaceuticals, and surfactants, in sewage treatment plant effluent. Responding to the growth of concentrated animal feeding operations (CAFOs) and the pollutants present in their wastewater (e.g., nutrients, pharmaceuticals, and hormones), the U.S. Environmental Protection Agency developed a new rule that tightens the regulation of CAFOs. In this study, we collected wild fathead minnows (Pimephales promelas) exposed to feedlot effluent (FLE) and observed significant alterations in their reproductive biology. Male fish were demasculinized (having lower testicular testosterone synthesis, altered head morphometrics, and smaller …

Evaluating The Human Relevance Of Chemically Induced Animal Tumors, Samuel M. Cohen, James Klaunig, M. Elizabeth Meek, Richard N. Hill, Timothy Pastoor, Lois Lehman-Mckeeman, John Bucher, David G. Longfellow, Jennifer Seed, Vicki Dellarco, Penelope Fenner-Crisp, Dorothy Patton

United States Environmental Protection Agency: Publications

Defining the mode(s) of action by which chemicals induce tumors in laboratory animals has become a key to judgments about the relevance of such tumor data for human risk assessment. Frameworks for analyzing mode of action information appear in recent U.S. EPA and IPCS publications relating to cancer risk assessment. This FORUM paper emphasizes that mode of action analytical frameworks depend on both qualitative and quantitative evaluations of relevant data and information: (1) presenting key events in the animal mode of action, (2) developing a “concordance” table for side-by-side comparison of key events as defined in animal studies with comparable …

United States Air Force Posture Statement 2004, U.S. Air Force

United States Air Force: Publications

In 2003, U.S. and coalition military operations produced unprecedented mission successes - across the spectrum of conflict and around the globe. The joint warfighting team demonstated combat capability never previously witnessed in the history of conflict.

Nebraska Summary 477: Agco Rt120 Powrmaxx Diesel, Nebraska Tractor Test Lab

Nebraska Tractor Tests

No abstract provided.

Structure/Function Analyses Of Human Serum Paraoxonase (Hupon1) Mutants Designed From A Dfpase-Like Homology Model, David T. Yeung, Denis Josse, James D. Nicholson, Akhil Khanal, Christopher W. Mcandrew, Brian B. Bahnson, David E. Lenz, Douglas M. Cerasoli

United States Army: Publications

Human serum paraoxonase (HuPON1) is a calcium-dependent enzyme that hydrolyzes esters, including organophosphates and lactones, and exhibits anti-atherogenic properties. A few amino acids have been shown to be essential for the enzyme’s arylesterase and organophosphatase activities. Until very recently, a three-dimensional model was not available for HuPON1, so functional roles have not been assigned to those residues. Based on sequence-structure alignment studies, we have folded the amino acid sequence of HuPON1 onto the sixfold β-propeller structure of squid diisopropylfluorophosphatase (DFPase). We tested the validity of this homology model by circular dichroism (CD) spectroscopy and site-directed mutagenesis. Consistent with predictions from …

Tests 2146 & 2147: Case Ih Jx 65 Diesel Series Ii, Nebraska Tractor Test Lab

Nebraska Tractor Tests

No abstract provided.

Tests 2177 & 2178: Case Ih Jx 85 Diesel Series Ii, Nebraska Tractor Test Lab

Nebraska Tractor Tests

No abstract provided.

Tests 2162 & 2163: Case Ih Jx 1070c Diesel, Nebraska Tractor Test Lab

Nebraska Tractor Tests

No abstract provided.

Detection Of Antibodies To Squalene Iii. Naturally Occurring Antibodies To Squalene In Humans And Mice, Gary R. Matyas, Mangala Rao, Phillip R. Pittman, Robert Burge, Iris E. Robbins, Nabila M. Wassef, Brandie Thivierge, Carl R. Alving

United States Army: Publications

An ELISA-based assay is described for the measurement of antibodies to squalene (SQE) in human serum and plasma. The assay was adapted from the previously described assay for murine antibodies to SQE (J. Immunol. Methods 267 (2002) 119). Like the murine SQE antibody assay, the human antibody assay used sterile cell culture 96-well plates coated with SQE (20 nmol/well). Phosphate-buffered saline (PBS)–0.5% casein was used as both a blocking agent and dilution buffer. The assay has a high through-put capacity and is reproducible and quantitative. This assay was used to evaluate samples from three different human cohorts. The first cohort …

Biomimetic Model Of Skeletal Muscle Isometric Contraction: I. An Energetic–Viscoelastic Model For The Skeletal Muscle Isometric Force Twitch, C. A. Phillips, D. W. Repperger, A. T. Neidhard-Doll, D. B. Reynolds

United States Air Force: Publications

This paper describes a revision of the Hill-type muscle model so that it will describe the chemo-mechanical energy conversion process (energetic) and the internal-element sti2ness variation (viscoelastic) during a skeletal muscle isometric force twitch contraction. The derivation of this energetic–viscoelastic model is described by a 3rst-order linear ordinary di2erential equation with constant energetic and viscoelastic coe5cients. The model has been implemented as part of a biomimetic model, which describes the excitation–contraction coupling necessary to drive the energetic–viscoelastic model. Finally, the energetic–viscoelastic model is validated by comparing its isometric force–time pro3le with that of various muscles reported in the literature.

Biogeochemical Transformation Of Fe Minerals In A Petroleum-Contaminated Aquifer, John M. Zachara, Ravi K. Kukkadapu, Paul L. Gassman, Alice Dohnalkova, Jim K. Fredrickson, Todd Anderson

United States Department of Energy: Publications

The Bemidji aquifer in Minnesota, USA is a well-studied site of subsurface petroleum contamination. The site contains an anoxic groundwater plume where soluble petroleum constituents serve as an energy source for a region of methanogenesis near the source and bacterial Fe(III) reduction further down gradient. Methanogenesis apparently begins when bioavailable Fe(III) is exhausted within the sediment. Past studies indicate that Geobacter species and Geothrix fermentens–like organisms are the primary dissimilatory Fe-reducing bacteria at this site. The Fe mineralogy of the pristine aquifer sediments and samples from the methanogenic (source) and Fe(III) reducing zones were characterized in this study to …

Reduction Of Tco4- By Sediment-Associated Biogenic Fe(Ii), James K. Fredrickson, John M. Zachara, David W. Kennedy, Ravi K. Kukkadapu, James P. Mckinley, Steve M. Heald, Chongxuan Liu, Andrew E. Plymale

United States Department of Energy: Publications

The potential for reduction of ⁹⁹TcO₄^-_(aq) to poorly soluble ⁹⁹TcO₂ · nH₂O_(s) by biogenic sediment-associated Fe(II) was investigated with three Fe(III)-oxide containing subsurface materials and the dissimilatory metal-reducing subsurface bacterium Shewanella putrefaciens CN32. Two of the subsurface materials from the U.S. Department of Energy’s Hanford and Oak Ridge sites contained significant amounts of Mn(III,IV) oxides and net bioreduction of Fe(III) to Fe(II) was not observed until essentially all of the hydroxylamine HCl-extractable Mn was reduced. In anoxic, unreduced sediment or where Mn oxide bioreduction was incomplete, exogenous biogenic TcO_{2 …}

Synthesis Of Colloidal Mn2+:Zno Quantum Dots And High-Tc Ferromagnetic Nanocrystalline Thin Films, Nick S. Norberg, Kevin R. Kittilstved, James E. Amonette, Ravi K. Kukkadapu, Dana A. Schwartz, Daniel R. Gamelin

United States Department of Energy: Publications

We report the synthesis of colloidal Mn²⁺-doped ZnO (Mn²⁺:ZnO) quantum dots and the preparation of room-temperature ferromagnetic nanocrystalline thin films. Mn²⁺:ZnO nanocrystals were prepared by a hydrolysis and condensation reaction in DMSO under atmospheric conditions. Synthesis was monitored by electronic absorption and electron paramagnetic resonance (EPR) spectroscopies. Zn(OAc)₂ was found to strongly inhibit oxidation of Mn²⁺ by O₂, allowing the synthesis of Mn2+:ZnO to be performed aerobically. Mn2+ ions were removed from the surfaces of as-prepared nanocrystals using dodecylamine to yield high-quality internally doped Mn2+:ZnO colloids of nearly spherical shape …