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Iowa State University

2008

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Articles 1 - 30 of 61

Full-Text Articles in Engineering

Residual Stresses In Friction-Stir-Welded 2195 And 7075 Aluminum Alloys, Omar Hatamleh, Iris V. Rivero, Arif Maredia Dec 2008

Residual Stresses In Friction-Stir-Welded 2195 And 7075 Aluminum Alloys, Omar Hatamleh, Iris V. Rivero, Arif Maredia

Iris V. Rivero

Surface residual stresses (RSs) were characterized along friction-stir-welded 2195 and 7075 aluminum alloy (AA) plates. The surface measurements were obtained through X-ray diffraction (XRD) at five different locations along the weld. Each location consisted of several regions across the welded plate including the weld nugget, thermomechanically affected zone (TMAZ), heat-affected zone (HAZ), and base material. Measurements revealed that RSs were not uniform along the welded plate, with the highest RSs obtained on the middle of the plate. The RSs across the weld were also asymmetric relative to the weld centerline, with RSs as high as 231 MPa in the TMAZ …


Flowability And Handling Characteristics Of Bulk Solids And Powders—A Review With Implications For Ddgs, V. Ganesan, Kurt A. Rosentrater, Kasiviswanathan Muthukumarappan Dec 2008

Flowability And Handling Characteristics Of Bulk Solids And Powders—A Review With Implications For Ddgs, V. Ganesan, Kurt A. Rosentrater, Kasiviswanathan Muthukumarappan

Kurt A. Rosentrater

Much research regarding handling and storage characteristics of bulk solids has been conducted over the years. Physical properties of granular solids play a significant role in their resulting storage and flow behaviour, and are therefore essential to design appropriate, efficient, and economic bulk solids handling and storage equipment and structures. Distillers Dried Grains with Solubles (DDGS) is a bulk material that has been widely used as a protein source for ruminants and non-ruminants for more than two decades. Distillers grains are energy and nutrient dense, and are often used as a replacement for corn in animal diets. With the exponential …


Understanding Consumer Preference For Functional Barley Tortillas Through Sensory, Demographic, And Behavioral Data, Ayako Toma, Maria Botero Omary, Kurt A. Rosentrater, Elizabeth A. Arndt, Naruemon Prasopsunwattana, Sutida Chongcham, Rolando A. Flores Nov 2008

Understanding Consumer Preference For Functional Barley Tortillas Through Sensory, Demographic, And Behavioral Data, Ayako Toma, Maria Botero Omary, Kurt A. Rosentrater, Elizabeth A. Arndt, Naruemon Prasopsunwattana, Sutida Chongcham, Rolando A. Flores

Kurt A. Rosentrater

Consumption of whole grains as part of a health-promoting diet is encouraged among Americans due to beneficial nutrients and phytochemicals. The main objectives of this study were to investigate the effect of whole barley flour particle size on consumer acceptance of whole grain and soluble fiber-enriched tortillas; to examine the effect of demographic and behavioral data on consumer acceptance; and to establish relationships between consumer acceptance and survey results to identify market opportunities among particular groups of consumers. Four experimental tortillas and two representative commercial brands were tested by 95 untrained panelists using a 9-point hedonic scale for appearance, color, …


No Evidence That Bacillus Thuringiensis Genes And Their Products Influence The Susceptibility Of Corn Residue To Decomposition, R. Michael Lehman, Shannon L. Osborne, Kurt A. Rosentrater Nov 2008

No Evidence That Bacillus Thuringiensis Genes And Their Products Influence The Susceptibility Of Corn Residue To Decomposition, R. Michael Lehman, Shannon L. Osborne, Kurt A. Rosentrater

Kurt A. Rosentrater

The possibility that Bacillus thuringiensis (Bt) corn (Zea mays L.) residues resist decomposition compared to non-Bt residues would present direct (soil carbon turnover times) and indirect (changes in tillage practices) effects on carbon budgets in agricultural systems. We evaluated the relative decomposition of residue from two pairs of Bt and non-Bt corn hybrids from different seed manufacturers buried in the root zone of adjacent Bt and non-Bt corn plots over a period of 384 d. We found no persistent differences in residue decomposition among the different hybrids regardless of the seed manufacturer or the presence of the Bt genes (both …


Determination Of Machining Parameters Of Corn Byproduct Filled Plastics, Kurt A. Rosentrater Nov 2008

Determination Of Machining Parameters Of Corn Byproduct Filled Plastics, Kurt A. Rosentrater

Kurt A. Rosentrater

In a collaborative project between the USDA and Northern Illinois University, the use of ethanol corn processing by-products as bio-filler materials in the compression molding of phenolic plastics has been studied. This paper reports on the results of a machinability study in the milling of various grades of this material. Three types of samples were studied: 100%, 75% and 50% phenolic samples. The milling operation was carried out with a fixed depth of cut of 2.0 mm using a 12.5 mm diameter two-fluted end-mill. The cutting speed was varied between 120 and 160 m/min at feeds between 200 and 300 …


Flow Properties Of Ddgs With Varying Soluble And Moisture Contents Using Jenike Shear Testing, V. Ganesan, Kasiviswanathan Muthukumarappan, Kurt A. Rosentrater Oct 2008

Flow Properties Of Ddgs With Varying Soluble And Moisture Contents Using Jenike Shear Testing, V. Ganesan, Kasiviswanathan Muthukumarappan, Kurt A. Rosentrater

Kurt A. Rosentrater

Distillers dried grains with solubles (DDGS) are an excellent source of energy, minerals, and bypass protein for ruminants and are used in monogastric rations as well. With the remarkable growth of the US fuel ethanol industry in the past decade, large quantities of distillers grains are now being produced. Flow of DDGS is often restricted by caking and bridging during its storage and transportation. In our previous works, the Carr powder tester was used to measure various flow properties of DDGS. The objective of this study was to measure the flow properties (cohesion, effective angle of friction, internal angle of …


Ifees: Enhancing Engineering Education At A Global Scale, Lueny Morrell, Claudio Borri, Hans J. Hoyer, Sarah A. Rajala, Seeram Ramakrishna, Xavier Fouger, Bruno Laporte, José Carlos Quadrado, Maria M. Larrondo Petrie, Duncan Mckenzie Frasier Oct 2008

Ifees: Enhancing Engineering Education At A Global Scale, Lueny Morrell, Claudio Borri, Hans J. Hoyer, Sarah A. Rajala, Seeram Ramakrishna, Xavier Fouger, Bruno Laporte, José Carlos Quadrado, Maria M. Larrondo Petrie, Duncan Mckenzie Frasier

Sarah A. Rajala

Engineering and technology play a key role in globalization as developed and developing countries develop and implement effective and efficient strategies that advance their economies and social development. Engineering has played a critical role in economic development in the history of civilization, because engineers are important not only in solving local problems but also in knowledge creation and knowledge transfer. Thus, science and technology education need to be in continuous evolvement in order to keep assisting countries reduce poverty, boost socio-economic development and make the right decisions for sustainable and environmentally compatible development. In a flat world, a global approach …


Unsteady Nanoscale Thermal Transport Across A Solid-Fluid Interface, Ganesh Balasubramanian, Soumik Banerjee, Ishwar K. Puri Sep 2008

Unsteady Nanoscale Thermal Transport Across A Solid-Fluid Interface, Ganesh Balasubramanian, Soumik Banerjee, Ishwar K. Puri

Ganesh Balasubramanian

We simulate unsteady nanoscale thermal transport at a solid-fluidinterface by placing cooler liquid-vapor Ar mixtures adjacent to warmer Fe walls. The equilibration of the system towards a uniform overall temperature is investigated using nonequilibrium molecular dynamics simulations from which the heat flux is also determined explicitly. The Ar–Fe intermolecular interactions induce the migration of fluid atoms into quasicrystallineinterfacial layers adjacent to the walls, creating vacancies at the migration sites. This induces temperature discontinuities between the solidlikeinterfaces and their neighboring fluid molecules. The interfacial temperature difference and thus the heat flux decrease as the system equilibrates over time. The averaged interfacial …


Improved Uses And Values For The Byproducts Of The Developing Biofuels Industry, Kurt A. Rosentrater Aug 2008

Improved Uses And Values For The Byproducts Of The Developing Biofuels Industry, Kurt A. Rosentrater

Kurt A. Rosentrater

No abstract provided.


Sum Frequency Generation Vibrational Spectroscopy Of Pyridine Hydrogenation On Platinum Nanoparticles, Kaitlin M. Bratlie, Kyriakos Komvopoulos, Gabor A. Somorjai Aug 2008

Sum Frequency Generation Vibrational Spectroscopy Of Pyridine Hydrogenation On Platinum Nanoparticles, Kaitlin M. Bratlie, Kyriakos Komvopoulos, Gabor A. Somorjai

Kaitlin M. Bratlie

Pyridine hydrogenation in the presence of a surface monolayer consisting of cubic Pt nanoparticles stabilized by tetradecyltrimethylammonium bromide (TTAB) was investigated by sum frequency generation (SFG) vibrational spectroscopy using total internal reflection (TIR) geometry. TIR-SFG spectra analysis revealed that a pyridinium cation (C5H5NH+) forms during pyridine hydrogenation on the Pt nanoparticle surface, and the NH group in the C5H5NH+ cation becomes more hydrogen bound with the increase of the temperature. In addition, the surface coverage of the cation decreases with the increase of the temperature. An important contribution of this study is the in situ identification of reaction intermediates adsorbed …


On The Physical Properties Of Distillers Dried Grains With Solubles (Ddgs), Klein Ileleji, Kurt A. Rosentrater Jul 2008

On The Physical Properties Of Distillers Dried Grains With Solubles (Ddgs), Klein Ileleji, Kurt A. Rosentrater

Kurt A. Rosentrater

Distillers dried grains with solubles (DDGS) is a complex heterogeneous granular solid that exhibit a wide range of physical and chemical properties. This fact is one of the major reasons that livestock nutritionists often find it difficult to include it in their feed rations. The rapid growth of the corn ethanol industry, the primary generator of DDGS, has resulted in a huge influx of this product into the marketplace. Unfortunately, the lack of standard methods for product quality determination and reporting is becoming a bottleneck to expanding the market for this product. Challenges in the logistics of moving DDGS through …


Effect Of Moisture Content And Soluble Level On The Physical, Chemical, And Flow Properties Of Distillers Dried Grains With Solubles (Ddgs), Vykundeshwari Ganesan, Kasiviswanathan Muthukumarappan, Kurt A. Rosentrater Jul 2008

Effect Of Moisture Content And Soluble Level On The Physical, Chemical, And Flow Properties Of Distillers Dried Grains With Solubles (Ddgs), Vykundeshwari Ganesan, Kasiviswanathan Muthukumarappan, Kurt A. Rosentrater

Kurt A. Rosentrater

Distillers dried grains with solubles (DDGS) is a bulk material that has been widely used as a protein source for ruminants and nonruminants for more than two decades. DDGS is the nonfermentable processing residue (i.e., protein, fiber, fat, and ash) from fuel ethanol manufacturing. With the exponential growth of the fuel ethanol industry in the past several years, significant quantities (≈13.0 million tons in 2007) of distillers grains are now being produced. To effectively utilize these coproduct streams in the domestic market, DDGS must be transported greater distances and must be stored until final use. DDGS flow is often problematic …


Not Just Informative, But Necessary: Infusing Green And Sustainable Topics Into Engineering And Technology Curricula, Kurt A. Rosentrater, Elif Kongar Jun 2008

Not Just Informative, But Necessary: Infusing Green And Sustainable Topics Into Engineering And Technology Curricula, Kurt A. Rosentrater, Elif Kongar

Kurt A. Rosentrater

Generally accepted duties of engineers and technologists encompass designing and implementing solutions to problems. When so doing, it is their responsibility to be cognizant of the impacts of their designs on, and thus their accountability to, not only society in general, but also subsequent effects upon the environment. They need to be able to concurrently satisfy these competing needs, as well as constraints specific to the design challenges at hand. Responding to these requirements are the growing fields of green engineering and sustainable engineering. Both of these areas encompass many concepts, ideas, and tools, all of which are essential information …


The Biomass Bandwagon: Three Ideas For Engineering And Technology Programs To Get Onboard, Kurt A. Rosentrater, Jerry Visser Jun 2008

The Biomass Bandwagon: Three Ideas For Engineering And Technology Programs To Get Onboard, Kurt A. Rosentrater, Jerry Visser

Kurt A. Rosentrater

As society demands more energy and material goods, engineers and technologists will be relied upon to design and implement systems to produce and deliver these. There is growing interest in using renewable resources to produce fuels, chemicals, and finished products to meet these increasing needs. Additionally, popularity is gaining, both in research as well as industry, in developing and commercializing biobased products. Within this arena, there are tremendous opportunities for teaching innovations as well. To date, very limited discussions at ASEE regarding these potentials have occurred. The goal of this paper is to discuss possibilities for augmenting engineering and technology …


Engineering Education Societies Becoming Global: The Evolving Development Of The International Federation Of Engineering Education Societies (Ifees), Lueny Morell, Claudio Borri, Sarah A. Rajala, Bruno Laporte, Maira M. Larrondo Petrie, Seeram Ramakrishna, Xavier Fouger, Adriana Garboan, Jose Carlos Quadrado, Duncan Fraser, Hans Hoyer Jun 2008

Engineering Education Societies Becoming Global: The Evolving Development Of The International Federation Of Engineering Education Societies (Ifees), Lueny Morell, Claudio Borri, Sarah A. Rajala, Bruno Laporte, Maira M. Larrondo Petrie, Seeram Ramakrishna, Xavier Fouger, Adriana Garboan, Jose Carlos Quadrado, Duncan Fraser, Hans Hoyer

Sarah A. Rajala

Globalization is making both developed and developing countries think about effective and efficient strategies that will advance their economies and social development. Throughout the history of civilization, engineering has played a critical role in economic development. Engineers are key not only in solving local problems but also in knowledge creation and knowledge transfer. Thus, it is imperative that technical know-how be supplemented with professional skills to develop an ‘adaptive leader’ who is capable of addressing the multiple challenges of an ever changing world. The key-question posed by the 21st century global economy to engineering educators and stake-holders is this: “How …


Quantifying Uncertainty Of Construction Material Price Volatility Using Monte Carlo, Douglas D. Gransberg, Erin J. Kelly Jun 2008

Quantifying Uncertainty Of Construction Material Price Volatility Using Monte Carlo, Douglas D. Gransberg, Erin J. Kelly

Douglas D. Gransberg

This study uses Monte Carlo simulation to derive a quantitative measure of construction price volatility for two case study projects in Oklahoma. In the past four years, the impact of events like Hurricane Katrina and the economic growth in China have induced unprecedented volatility in US construction prices. This has caused a huge number of public construction project bids to exceed the owners' estimates, making it difficult for public construction agencies to be able to predict construction budgets. Construction prices are a function of many factors beyond pure material costs. This study broke down the pay items from a typical …


Effects Of Feed And Extruder Parameters On Extrudates Containing Ddgs, S. Kannadhason, Kasiviswanathan Muthukumarappan, Kurt A. Rosentrater Jun 2008

Effects Of Feed And Extruder Parameters On Extrudates Containing Ddgs, S. Kannadhason, Kasiviswanathan Muthukumarappan, Kurt A. Rosentrater

Kurt A. Rosentrater

Twenty seven isocaloric (3.05 kcal/g) ingredient blends were factorially formulated using three levels each of DDGS (20, 25, and 30% db), protein (30, 32.5, and 35% db), and feed moisture content (25, 35, and 45% db), along with appropriate quantities of cassava starch, soybean meal, fish meal, whey, vitamin, and mineral mix to produce a balanced diet for tilapia feed. The ingredient blends were extruded using a laboratory-scale single screw extruder with varying screw speeds (100, 150, and 200 rpm) and extruder barrel temperatures (100, 125, and 150 o C). The resulting extrudates were subjected to extensive analyses of physical …


Understanding And Modeling Flowability Of Ddgs, Rumela Bhadra, Kurt A. Rosentrater, Kasiviswanathan Muthukumarappan Jun 2008

Understanding And Modeling Flowability Of Ddgs, Rumela Bhadra, Kurt A. Rosentrater, Kasiviswanathan Muthukumarappan

Kurt A. Rosentrater

Distillers dried grains with solubles (DDGS), the major coproduct from the corn-based fuel ethanol industry, is primarily used as livestock feed. Due to high protein, fiber, and energy contents, there is a high demand for DDGS. Flowability of DDGS is often hindered due the phenomenon of “caking”. Shipping and handling of DDGS has thus become a major issue due to bridge formation between the DDGS particles. The objective of this investigation was to measure flowability characteristics of DDGS samples from five ethanol plants in the north central region of the U.S. Carr and Jenike tests were performed, and the resulting …


Twin Screw Extrusion Of Ddgs-Based Aquaculture Feeds, S. Kannadhason, Kurt A. Rosentrater, Kasiviswanathan Muthukumarappan, Micahel L. Brown Jun 2008

Twin Screw Extrusion Of Ddgs-Based Aquaculture Feeds, S. Kannadhason, Kurt A. Rosentrater, Kasiviswanathan Muthukumarappan, Micahel L. Brown

Kurt A. Rosentrater

Six isocaloric (3.65 kcal/g), isonitrogenous (35% db protein), ingredient blends were prepared with 0, 17.5, 20, 22.5, 25, and 27.5% DDGS and other common ingredients, including soybean meal, corn, fish meal, whey, soybean oil, and vitamin and mineral mix, in order to produce balanced rations appropriate for tilapia grower diets. The blends were moisture balanced to 15% db, and then extruded in a pilot-scale twin screw extruder. The extrusion process was carried out using two processing conditions: a 2 mm die at 190 rpm (with temperatures ranging from 80 to 110 o C, depending on barrel location), and a 3 …


Surface Characteristics And Flowability Of Distillers Dried Grains With Solubles, Rumela Bhadra, Kurt A. Rosentrater, Kasiviswanathan Muthukumarappan Jun 2008

Surface Characteristics And Flowability Of Distillers Dried Grains With Solubles, Rumela Bhadra, Kurt A. Rosentrater, Kasiviswanathan Muthukumarappan

Kurt A. Rosentrater

With an annual production of approximately 6.5 billion gallons of fuel ethanol, and projected growth for the foreseeable future, supplies of coproducts such distillers dried grain with solubles (DDGS) are anticipated to continue to grow as well. DDGS is used primarily as livestock feed. Much of the DDGS must be shipped, often over large distances throughout the country, as much of the livestock (especially large dairies and feedlots) are outside the Corn Belt, where most of the ethanol plants are currently located. “Caking”, or stickiness, among particles is an important issue related to DDGS, especially when it leads to flowability …


Raman Multiplexers For Alternative Gene Splicing, Lan Sun, Chenxu Yu, Joseph Irudayaraj May 2008

Raman Multiplexers For Alternative Gene Splicing, Lan Sun, Chenxu Yu, Joseph Irudayaraj

Chenxu Yu

Nonfluorescent labels were used for an array-format multiplex detection of alternative splice junctions of breast cancer susceptibility gene 1 (BRCA1) by surface-enhanced Raman scattering (SERS). A four-plex detection scheme using nonfluorescent labels was demonstrated for DNA sequences specific to four BRCA1 alternative splice variants:  Δ(11q) (the last 3309 nt deleted from exon 11), Δ(9, 10) (exon 9 and 10 deleted), Δ(5) (exon 5 deleted), and Δ(5q, 6) (the last 22 nt of exon 5 and the entire exon 6 is deleted). This is the first proof-of-concept study to apply SERS-based detection using nonfluorescent labels to investigate alternative gene splicing. Detection …


Low-Energy Antiphase Boundaries, Degenerate Superstructures, And Phase Stability In Frustrated Fcc Ising Model And Ag-Au Alloys, Nikolai A. Zarkevich, Teck L. Tan, Lin-Lin Wang, Duane D. Johnson Apr 2008

Low-Energy Antiphase Boundaries, Degenerate Superstructures, And Phase Stability In Frustrated Fcc Ising Model And Ag-Au Alloys, Nikolai A. Zarkevich, Teck L. Tan, Lin-Lin Wang, Duane D. Johnson

Duane D. Johnson

An Ising model exhibits zero-energy antiphase boundaries (APBs) and frustration on close-packed face-centered cubic (fcc) and triangular lattices. The frustration results in degenerate structures and chains of long-period superstructures forming a quasicontinuous ground-state “hull” in the formation energy versus composition (c) diagram. In alloys, a nonzero but small APB energy yields a c-dependent reduction in this degeneracy that affects the phase diagram topology and range of the two-phase coexistence. Using density functional theory combined with cluster expansions (CEs), we study Ag-Au alloys as a prototype and find the effective cluster interactions (dominated by nearest-neighbor pairs), predict energetics of millions of …


Modeling The Effects Of Value-Added Processing And Logistics Using Arena, Kurt A. Rosentrater, Elif Kongar Mar 2008

Modeling The Effects Of Value-Added Processing And Logistics Using Arena, Kurt A. Rosentrater, Elif Kongar

Kurt A. Rosentrater

Scarcity and cost of nonrenewable fossil fuels have been a growing focus of many energy-dependent nations, including the U.S., for the past couple of decades. There are mainly two ways to approach these problems: (1) reducing the energy dependency and/or (2) developing alternative means of energy production. Utilizing biofuels, which are renewable sources of energy, is a promising way to produce energy. But, as this industry grows, so too does the quantity of byproducts, which are known as DDGS. This paper discusses a model that has been developed to analyze the economic viability of DDGS processing, and includes both deterministic …


Three-Dimensional Data Merging Using Holoimage, Song Zhang, Shing-Tung Yau Mar 2008

Three-Dimensional Data Merging Using Holoimage, Song Zhang, Shing-Tung Yau

Song Zhang

Three-dimensional data merging is vital for full-field three-dimensional (3D) shape measurement. All 3D range data patches, acquired from either different sensors or the same sensor in different viewing angles, have to be merged into a single piece to facilitate future data analysis. A novel method for 3D data merging using Holoimage is proposed. Similar to the 3D shape measurement system using a phase-shifting method, Holoimage is a phase-shifting–based computer synthesized fringe image. The 3D information is retrieved from Holoimage using a phase-shifting method. If two patches of 3D data with overlapping areas are rendered by OpenGL, the overlapping areas are …


In Vivo Ultrasonic Attenuation Slope Estimates For Detecting Cervical Ripening In Rats: Preliminary Results, Timothy A. Bigelow, Barbara L. Mcfarlin, William D. O'Brien Jr., Michael L. Oelze Mar 2008

In Vivo Ultrasonic Attenuation Slope Estimates For Detecting Cervical Ripening In Rats: Preliminary Results, Timothy A. Bigelow, Barbara L. Mcfarlin, William D. O'Brien Jr., Michael L. Oelze

Timothy A. Bigelow

To effectively postpone preterm birth, cervical ripening needs to be detected and delayed. As the cervix ripens, the spacing between the collagen fibers increases and fills with water, hyaluronan, decorin, and enzymes suggesting that the ultrasonic attenuation of the cervix should decrease. The decrease in ultrasonic attenuation may be detectable, leading to an effective means of detecting cervical ripening. Herein, the traditional attenuation slope-estimation algorithm based on measuring the downshift in center frequency of the ultrasonic backscattered signal with propagation depth was modified and applied to the cervix of rats. The modified algorithm was verified using computer simulations and an …


Effect Of Ddgs, Moisture Content, And Screw Speed On Physical Properties Of Extrudates In Single-Screw Extrusion, Nehru Chevanan, Kurt A. Rosentrater, Kasiviswanathan Muthukumarappan Mar 2008

Effect Of Ddgs, Moisture Content, And Screw Speed On Physical Properties Of Extrudates In Single-Screw Extrusion, Nehru Chevanan, Kurt A. Rosentrater, Kasiviswanathan Muthukumarappan

Kurt A. Rosentrater

Three isocaloric (3.5 kcal/g) ingredient blends containing 20, 30, and 40% (wb) distillers dried grains with solubles (DDGS) along with soy flour, corn flour, fish meal, and mineral and vitamin mix, with net protein adjusted to 28% (wb) for all blends, were extruded in a single-screw laboratory-scale extruder at screw speeds of 100, 130, and 160 rpm, and 15, 20, and 25% (wb) moisture content. Increasing DDGS content from 20 to 40% resulted in a 37.1, 3.1, and 8.4% decrease in extrudate durability, specific gravity, and porosity, respectively, but a 7.5% increase in bulk density. Increasing screw speed from 100 …


Mycotoxins In Corn Distillers Grains: A Concern In Ruminants?, Alvaro Garcia, Kenneth Kalscheur, Arnold Hippen, David Schingoethe, Kurt A. Rosentrater Mar 2008

Mycotoxins In Corn Distillers Grains: A Concern In Ruminants?, Alvaro Garcia, Kenneth Kalscheur, Arnold Hippen, David Schingoethe, Kurt A. Rosentrater

Kurt A. Rosentrater

Themain fungi that produce toxins during storage belong to three genera: Aspergillus, Fusarium, and Penicillium. When dealing with cattle diets, it is not easy to correlate the presence of mycotoxins to that of molds. The same types of molds can produce different types of toxins, and different types ofmolds can produce the samemycotoxin.


Grain Growth And Texture Development In Lithium Fluoride Thin Films, Hakkwan Kim, Alexander H. King Feb 2008

Grain Growth And Texture Development In Lithium Fluoride Thin Films, Hakkwan Kim, Alexander H. King

Alexander H. King

We have studied grain-growth and texture development in polycrystalline lithium fluoride thin films using dark-field transmission electron microscopy. We demonstrate that we can isolate the size distribution of 〈111〉 surface normal grains from the overall size distribution, based on simple and plausible assumptions about the texture. The {111} texture formation and surface morphology were also observed by x-ray diffraction and atomic force microscopy, respectively. The grain-size distributions become clearly bimodal as the annealing time increases, and we deduce that the short-time size distributions are also a sum of two overlapping peaks. The smaller grain-size peak in the distribution corresponds to …


Predicting Enthalpies Of Molecular Substances: Application To Libh4, Nikolai A. Zarkevich, Duane D. Johnson Feb 2008

Predicting Enthalpies Of Molecular Substances: Application To Libh4, Nikolai A. Zarkevich, Duane D. Johnson

Duane D. Johnson

For molecular substances exhibiting harmonic and nonharmonic vibrations, we present a first-principles approach to predict enthalpy differences between phases at finite temperatures, including solid-solid and melting. We apply it to the complex hydride LiBH4. Using ab initio molecular dynamics, we predict a structure for the high-T solid phase of lithium borohydride, and we propose an approximation to account for nonharmonic vibrations. We then predict the enthalpy changes for solid-solid transition, melting, and an H-storage reaction, all in agreement with experiment.


Three-Dimensional Shape Measurement Using A Structured Light System With Dual Cameras, Song Zhang, Shing-Tung Yau Jan 2008

Three-Dimensional Shape Measurement Using A Structured Light System With Dual Cameras, Song Zhang, Shing-Tung Yau

Song Zhang

A structured light system for three-dimensional shape measurement with single camera has the shortcoming of camera occlusion. To alleviate this problem, this paper introduces a structured light system with dual cameras for three-dimensional shape measurement. We discuss (1) system description, (2) system calibration, (3) three-dimensional data registration using the iterative closest-point (ICP) algorithm, and (4) three-dimensional data merging using holoimage. The principle of the system is introduced, and experiments are presented to verify its performance.