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Numerical Prediction Of Exhaust Fan-Tone Noise From High-Bypass Aircraft Engines, Anupam Sharma, Simon K. Richards, Trevor H. Wood, Chingwei Shieh Dec 2009

Numerical Prediction Of Exhaust Fan-Tone Noise From High-Bypass Aircraft Engines, Anupam Sharma, Simon K. Richards, Trevor H. Wood, Chingwei Shieh

Anupam Sharma

The ability to accurately predict fan noise is important in designing and optimizing high-bypass aircraft engines for low noise emissions. In this paper, a prediction methodology for exhaust fan-tone noise analysis is described and validated against various canonical test cases and NASA Source Diagnostic Test data (Heidelberg, L. J., "Fan Noise Source Diagnostic Test-Tone Modal Structure Results," NASA TM-2002-211594, 2002.). The prediction process consists of solving Reynolds-averaged Navier-Stokes equations to compute the fan wake and calculating the acoustic response of the outlet guide vanes to the fan wake using linearized Euler equations. Very good agreement is observed between the numerical …


Modeling The Effects Of Pelleting On The Logistics Of Distillers Grains Shipping, Kurt A. Rosentrater, Elif Kongar Dec 2009

Modeling The Effects Of Pelleting On The Logistics Of Distillers Grains Shipping, Kurt A. Rosentrater, Elif Kongar

Kurt A. Rosentrater

The energy security needs of energy importing nations continue to escalate. It is clear that biofuels can help meet some of the increasing need for energy. Theoretically, these can be produced from a variety of biological materials, including agricultural residues (such as corn stover and wheat straw), perennial grasses, legumes, algae, and other biological materials. Currently, however, the most heavily utilized material is corn starch. Industrial fuel ethanol production in the US primarily uses corn, because it is readily converted into fuel at a relatively low cost compared to other biomass sources. The production of corn-based ethanol in the US …


Analysis Of Nonequilibrium Hcp Precipitate Growth In Fcc Matrices: Application To Al–Ag, Daniel Finkenstadt, Duane D. Johnson Nov 2009

Analysis Of Nonequilibrium Hcp Precipitate Growth In Fcc Matrices: Application To Al–Ag, Daniel Finkenstadt, Duane D. Johnson

Duane D. Johnson

Hexagonal-close-packed (hcp) γ-precipitates with large aspect ratios form rapidly in some face-centered cubic (fcc) solid-solutions. No model explains the observed time-dependent increase in aspect ratio, nor irregular intermediate growth shapes. We propose a nonequilibrium process involving trapezoidal offshoots (controlled only by energetics) that governs the growth behavior (kinetics) and yields nonequilibrium structures in agreement with observation. Then, combining nucleation theory and diffusion-limited growth both of secondary nuclei and ledges, we derive a general growth equation for γ-precipitates due to solute-segregation to precipitate–matrix interfaces that includes our modification of the Jones–Trivedi model for thickening to account for the slow growth of …


Intelligent Controller For Smart Base Isolation Of Masonry Structures, Simon Laflamme, T.Y. Yu, Jerome J. Connor Oct 2009

Intelligent Controller For Smart Base Isolation Of Masonry Structures, Simon Laflamme, T.Y. Yu, Jerome J. Connor

Simon Laflamme

In this paper, an intelligent controller to control a smart base-isolated masonry structure is proposed. The smart base isolation consists of rubber bearings and a magnetorheological damper. This semi-active scheme takes advantage of the low power requirement of magnetorheological devices to achieve structural control. The controller is capable of mapping the behaviour of the controlled structure sequentially, using a self-organizing neural network which has time-varying learning rates. This neurocontroller is augmented by a sliding mode controller to account for the uncertainty on the semi-active damping forces. Wavelets are used as functions in the single hidden layer for their capability of …


Costs Of Pelleting To Enhance The Logistics Of Distillers Grains Shipping, Kurt A. Rosentrater, Elif Kongar Oct 2009

Costs Of Pelleting To Enhance The Logistics Of Distillers Grains Shipping, Kurt A. Rosentrater, Elif Kongar

Kurt A. Rosentrater

Biofuels, especially corn-based ethanol, can help meet some of the increasing demand for transportation fuels. Currently, the most heavily utilized substrate is corn grain, which is readily converted into ethanol at a relatively low cost compared to other biomass sources. The production of ethanol in the U.S. has been dramatically increasing during the last several years; so too has the quantity of manufacturing coproducts. These nonfermentable residues are most often dried and sold as distillers dried grains with solubles – DDGS. Even though these materials are used to feed livestock in local markets, as the size of the industry continues …


Optimal Site-Centered Electronic Structure Basis Set From A Displaced-Center Expansion: Improved Results Via A Priori Estimates Of Saddle Points In The Density, Aftab Alam, Duane D. Johnson Sep 2009

Optimal Site-Centered Electronic Structure Basis Set From A Displaced-Center Expansion: Improved Results Via A Priori Estimates Of Saddle Points In The Density, Aftab Alam, Duane D. Johnson

Duane D. Johnson

Site-centered, electronic-structure methods use an expansion inside nonoverlapping “muffin-tin” (MT) spheres plus an interstitial basis set. As the boundary separating the more spherical from nonspherical density between atoms, the “saddle-point” radii (SPR) in the density provide an optimal spherical region for expanding in spherical harmonics, as used in augmented plane wave, muffin-tin orbital, and multiple-scattering [Korringa, Kohn, and Rostoker (KKR)] methods. These MT-SPR guarantee unique, convex Voronoi polyhedra at each site, in distinction to Bader topological cells. We present a numerically fast, two-center expansion to find SPR a priori from overlapping atomic charge densities, valid also for disordered alloys. We …


Visualising Rationale In The Cpm, David H. Mott, Michael C. Dorneich Sep 2009

Visualising Rationale In The Cpm, David H. Mott, Michael C. Dorneich

Michael C. Dorneich

Rationale is being explored by the ITA in planning, for shared understanding of plans, and for capturing dependencies between assumptions/decisions and parts of the plan. Informal rationale captured during evaluation of the Collaborative Planning Model has been explored in terms of alternative visual representations and questions that these raise.


Improving Shared Understanding In Multilevel Planning, Michael C. Dorneich, David Mott, Ali Bahrami, Jitu Patel Sep 2009

Improving Shared Understanding In Multilevel Planning, Michael C. Dorneich, David Mott, Ali Bahrami, Jitu Patel

Michael C. Dorneich

Planning is a specific example of a problem solving activity that is undertaken across multiple (human) collaborative agents. In order to collaborate, these humans need to form a shared understanding of various aspects of the plan, mutual goals, the contexts of the other agents, and the rationale for others decisions and assumptions. Failure to reach this shared understanding can have serious implications to the success of the resulting plan. Currently plans are developed and shared with peer and subordinate units in a static format such as text, diagrams and spreadsheets which do not normally contain any of the reasoning, logic …


The Effects Of Extrusion Processing Of Distillers Dried Grains With Solubles (Ddgs)-Based Yellow Perch (Perca Flavescens) Feeds, Ferouz Y. Ayadi, Kasiviswanathan Muthukumarappan, Kurt A. Rosentrater, Michael L. Brown Sep 2009

The Effects Of Extrusion Processing Of Distillers Dried Grains With Solubles (Ddgs)-Based Yellow Perch (Perca Flavescens) Feeds, Ferouz Y. Ayadi, Kasiviswanathan Muthukumarappan, Kurt A. Rosentrater, Michael L. Brown

Kurt A. Rosentrater

This study was conducted to investigate the production of balanced diets for juvenile yellow perch (Perca flavescens) feeds. Six isocaloric (~ 3.21 kcal/g), isonitrogenous (31.5% db) ingredient blends were formulated with 0, 10, 20, 30, 40, and 50% distillers dried grains with solubles (DDGS) at a feed moisture content of 60-65% db, with appropriate amounts of soybean meal, fish meal, vitamin and mineral mix. Extrusion cooking was performed using a laboratory-scale single screw extruder at a constant barrel temperature profile of 40ºC-90ºC-100ºC, and a constant screw speed of 230 rpm (24.1 rad/s). During processing the mass flow rate was determined, …


Sensory Evaluation Of Barley Chocolate Chip Cookies By Consumers With Different Demographic Background And Eating Patterns, Maria Botero Omary, Kurt A. Rosentrater, Douglas L. Lewis, Elizabeth Arndt, Diana J. Frost, Lauren M. Winstone Sep 2009

Sensory Evaluation Of Barley Chocolate Chip Cookies By Consumers With Different Demographic Background And Eating Patterns, Maria Botero Omary, Kurt A. Rosentrater, Douglas L. Lewis, Elizabeth Arndt, Diana J. Frost, Lauren M. Winstone

Kurt A. Rosentrater

Health organizations have recommended an increase in consumption of whole grains, total dietary fiber, and soluble fiber to help reduce the potential risk factor for the development of type-2 diabetes, obesity, and cardiovascular disease, among others. The purpose of this project was to determine the sensory characteristics of chocolate chip (CC) cookies containing a high-soluble fiber whole barley flour (HSFWB). Cookies with 0, 30, 50, and 70% HSFWB were evaluated for appearance, color, flavor, texture, and overall acceptability using a 9-point hedonic scale. Forty-nine students, faculty, and staff tested the cookies on three different days. Demographic and behavioral data on …


Measurement Of Sticky Point Temperature Of Coffee Powder With A Rheometer, Rumela Bhadra, Kurt A. Rosentrater, Kasiviswanathan Muthukumarappan Aug 2009

Measurement Of Sticky Point Temperature Of Coffee Powder With A Rheometer, Rumela Bhadra, Kurt A. Rosentrater, Kasiviswanathan Muthukumarappan

Kurt A. Rosentrater

Sticky point temperature (Ts) measurement for hygroscopic food and biomaterial powders is traditionally performed with complex glass instruments. This property is used to characterize material stickiness, which substantially affects the flow and physical behavior of powders. In this research study we developed a new methodology to measure sticky point temperature using a rheometer, and validated our Ts data with previously published coffee powder data. Our Ts measurement using a rheometer was performed in two replications. The behavior of Ts as a function of moisture content (%, db) was observed to be non-linear. After 16% (db) moisture content, however, there were …


Surface Geometry Of C60 On Ag(111), H. I. Li, K. Pussi, K. J. Hanna, Lin-Lin Wang, Duane D. Johnson, H.-P. Cheng, H. Shin, S. Curtarolo, W. Moritz, J. A. Smerdon, R. Mcgrath, R. D. Diehl Jul 2009

Surface Geometry Of C60 On Ag(111), H. I. Li, K. Pussi, K. J. Hanna, Lin-Lin Wang, Duane D. Johnson, H.-P. Cheng, H. Shin, S. Curtarolo, W. Moritz, J. A. Smerdon, R. Mcgrath, R. D. Diehl

Duane D. Johnson

The geometry of adsorbed C60 influences its collective properties. We report the first dynamical low-energy electron diffraction study to determine the geometry of a C60 monolayer, Ag(111)−(23√×23√)30°−C60, and related density functional theory calculations. The stable monolayer has C60 molecules in vacancies that result from the displacement of surface atoms. C60 bonds with hexagons down, with their mirror planes parallel to that of the substrate. The results indicate that vacancy structures are the rule rather than the exception for C60 monolayers on close-packed metal surfaces.


Pattern Formation During The Evaporation Of A Colloidal Nanoliter Drop: A Numerical And Experimental Study, Rajneesh Bhardwaj, Xiaohua Fang, Daniel Attinger Jul 2009

Pattern Formation During The Evaporation Of A Colloidal Nanoliter Drop: A Numerical And Experimental Study, Rajneesh Bhardwaj, Xiaohua Fang, Daniel Attinger

Daniel Attinger

An efficient way to precisely pattern particles on solid surfaces is to dispense and evaporate colloidal drops, as for bioassays. The dried deposits often exhibit complex structures exemplified by the coffee ring pattern, where most particles have accumulated at the periphery of the deposit. In this work, the formation of deposits during the drying of nanoliter colloidal drops on a flat substrate is investigated numerically and experimentally. A finite-element numerical model is developed that solves the Navier–Stokes, heat and mass transport equations in a Lagrangian framework. The diffusion of vapor in the atmosphere is solved numerically, providing an exact boundary …


Survey Of Us Fuel Ethanol Plants, Jessica A. Saunders, Kurt A. Rosentrater Jul 2009

Survey Of Us Fuel Ethanol Plants, Jessica A. Saunders, Kurt A. Rosentrater

Kurt A. Rosentrater

The ethanol industry is growing in response to increased consumer demands for fuel as well as the renewable fuel standard. Corn ethanol processing creates the following products: 1/3 ethanol, 1/3 distillers grains, and 1/3 carbon dioxide. As the production of ethanol increases so does the generation of its coproducts, and viable uses continually need to be developed. A survey was mailed to operational US ethanol plants to determine current practices. It inquired about processes, equipment used, end products, and desired future directions for coproducts. Results indicated that approximately one-third of plant managers surveyed expressed a willingness to alter current drying …


Quantitative Prediction Of Twinning Stress In Fcc Alloys: Application To Cu-Al, Sandeep A. Kibey, Lin-Lin Wang, J. B. Liu, H. T. Johnson, H. Sehitoglu, Duane D. Johnson Jun 2009

Quantitative Prediction Of Twinning Stress In Fcc Alloys: Application To Cu-Al, Sandeep A. Kibey, Lin-Lin Wang, J. B. Liu, H. T. Johnson, H. Sehitoglu, Duane D. Johnson

Duane D. Johnson

Twinning is one of most prevalent deformation mechanisms in materials. Having established a quantitative theory to predict onset twinning stress τcrit in fcc elemental metals from their generalized planar-fault-energy (GPFE) surface, we exemplify its use in alloys where the Suzuki effect (i.e., solute energetically favors residing at and near planar faults) is operative; specifically, we apply it in Cu-xAl (x is 0, 5, and 8.3 at. %) in comparison with experimental data. We compute the GPFE via density-functional theory, and we predict the solute dependence of the GPFE and τcrit, in agreement with measured values. We show that τcrit correlates …


A Comparison Of Measurement Procedures Used To Determine The Bulk Density Of Distillers Dried Grains With Solubles (Ddgs), Clairmont L. Clementson, Kurt A. Rosentrater, Klein E. Heleji Jun 2009

A Comparison Of Measurement Procedures Used To Determine The Bulk Density Of Distillers Dried Grains With Solubles (Ddgs), Clairmont L. Clementson, Kurt A. Rosentrater, Klein E. Heleji

Kurt A. Rosentrater

The production of corn-based ethanol in the U.S. has been dramatically increasing in recent years, and consequently so has the quantity of co-product, distillers dried grains with soluble (DDGS) generated from this processing sector. DDGS is sold as a commodity for animal feed and like corn; its bulk physical and chemical properties are quality attributes normally used in trading by merchandisers. Consistency in product quality have been cause for concern in the industry and the lack of standard methods for physical and chemical property determination does potentially confound the issue, especially when results of attributes measured by different methods have …


Physical And Flow Properties Of Regular And Reduced Fat Distillers Dried Grains With Solubles (Ddgs), Vykundeshwari Ganesan, Kurt A. Rosentrater, Kasiviswanathan Muthukumarappan Jun 2009

Physical And Flow Properties Of Regular And Reduced Fat Distillers Dried Grains With Solubles (Ddgs), Vykundeshwari Ganesan, Kurt A. Rosentrater, Kasiviswanathan Muthukumarappan

Kurt A. Rosentrater

With the remarkable growth of the US fuel ethanol industry in the past decade, large quantities of corn-based distillers dried grains with solubles (DDGS) are now being produced. Flowability of DDGS has become a problem throughout the industry, as it is often restricted by caking and bridging during storage and transport. The objective of this study was to quantify physical and flow properties of commercially produced unmodified (9.3% db fat) and reduced fat (2.1% db) DDGS to determine if fat level affects flowability. The compressive modulus of reduced fat DDGS was 28.2% higher than unmodified DDGS, but shear stress resistance …


Extrusion Studies Of Aquaculture Feed Using Distillers Dried Grains With Solubles And Whey, Nehru Chevanan, Kasiviswanathan Muthukumarappan, Kurt A. Rosentrater Jun 2009

Extrusion Studies Of Aquaculture Feed Using Distillers Dried Grains With Solubles And Whey, Nehru Chevanan, Kasiviswanathan Muthukumarappan, Kurt A. Rosentrater

Kurt A. Rosentrater

Three isocaloric (3.5 kcal/g) ingredient blends containing 20, 30, and 40% distiller-dried grains with solubles (DDGS) along with 5% whey were prepared with a net protein content adjusted to 28% (wet basis [wb]). Other ingredients in the blends included soy flour, corn flour, fish meal, vitamin, and mineral mix. These blends were extruded in a single-screw extruder at 15, 20, and 25% (wb) moisture content and at 130 and 160 rpm screw speeds. Compared to previous research, the durability and unit density of the extrudates in this study were found to increase substantially by the addition of whey to the …


A Treatise On The Application Of Lifecycle Management Principles In Agricultural & Biological Engineering, Israel S. Dunmade, Kurt A. Rosentrater Jun 2009

A Treatise On The Application Of Lifecycle Management Principles In Agricultural & Biological Engineering, Israel S. Dunmade, Kurt A. Rosentrater

Kurt A. Rosentrater

Life Cycle Management (LCM) is a systematic approach, mindset and culture that considers economic, social, and environmental factors among other factors in the decision making process throughout various business or organizational decisions that affect both inputs and outputs of a product or service life cycle. It is a product, process, or activity management system aimed at minimizing environmental and socio-economic burdens associated with an organization’s product or process during its entire life cycle and value chain. LCM’s application is gaining wider acceptance both in the corporate and governmental organizations as an approach to reduce ecological footprints and to improve the …


Effect Of Elusieve Fractionation On Physical Properties Of Distillers Dried Grains With Solubles (Ddgs), Kurt A. Rosentrater, Radhakrishnan Srinivasan Jun 2009

Effect Of Elusieve Fractionation On Physical Properties Of Distillers Dried Grains With Solubles (Ddgs), Kurt A. Rosentrater, Radhakrishnan Srinivasan

Kurt A. Rosentrater

The production of corn-based ethanol in the U.S. has been dramatically increasing in recent years, and consequently so has the quantity of coproduct materials generated from this processing sector. These streams are primarily utilized as livestock feed, and can partially offset the need for corn in feed rations. As the industry evolves, new technologies are being developed to improve the value proposition of the coproducts, especially distillers dried grains with solubles (DDGS). One of these is the Elusieve process, which combines sieving and air classification to accomplish fractionation of the DDGS into component-rich (i.e., protein, lipid, fiber) streams. Previous studies …


Cross-Sectional Staining And Surface Properties Of Ddgs Particles And Their Influence On Flowability, Rumela Bhadra, Kurt A. Rosentrater, Kasiviswanathan Muthukumarappan Jun 2009

Cross-Sectional Staining And Surface Properties Of Ddgs Particles And Their Influence On Flowability, Rumela Bhadra, Kurt A. Rosentrater, Kasiviswanathan Muthukumarappan

Kurt A. Rosentrater

With the U.S. fuel ethanol industry projected to grow during the next several years, supplies of distillers dried grains 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, outside the Corn Belt (which is where most of the corn-based ethanol plants are currently located). Stickiness and caking among particles is a common issue for DDGS, and it often leads to flowability problems. To address this, the objective of this study was to understand the cross-sectional and surface natures of DDGS …


Examining The Effects Of Ethanol Processing And Drying Conditions On The Physical Properties Of Distillers Dried Grains With Solubles (Ddgs), Kurt A. Rosentrater, Brian A. Wrenn May 2009

Examining The Effects Of Ethanol Processing And Drying Conditions On The Physical Properties Of Distillers Dried Grains With Solubles (Ddgs), Kurt A. Rosentrater, Brian A. Wrenn

Kurt A. Rosentrater

The production of corn-based ethanol in the U.S. has been dramatically increasing in recent years, and consequently so has the quantity of coproduct materials generated from this processing sector. These streams are primarily utilized as livestock feed, which partially offsets the need for corn in feed rations. Because of its use as an animal feed, considerable research has been conducted into the nutritional properties, and to some extent the physical properties, of commerciallyavailable distillers dried grains with solubles (DDGS). There are, however, occasions when the quality of coproducts is not consistent. Thus questions regarding the influence of production operations on …


A Data Envelopment Analysis Model For Renewable Energy Technology Selection, Elif Kongar, Kurt A. Rosentrater Apr 2009

A Data Envelopment Analysis Model For Renewable Energy Technology Selection, Elif Kongar, Kurt A. Rosentrater

Kurt A. Rosentrater

Public and media interest in alternative energy sources, such as renewable fuels, has rapidly increased in recent years due to higher prices for oil and natural gas. However, the current body of research providing comparative decision making models that either rank these alternative energy sources and/or determine the best possible alternatives is still limited. This paper aims at filling this gap by proposing a Data Envelopment Analysis (DEA) model structure for ranking energy source alternatives under varying circumstances. The model considers both the economics of energy sources and additional environmental criteria such as CO2 emissions and damage cost. Numerical examples …


Application Of Self-Tuning Gaussian Networks For Control Of Civil Structures Equipped With Magnetorheological Dampers, Simon Laflamme, Jerome J. Connor Apr 2009

Application Of Self-Tuning Gaussian Networks For Control Of Civil Structures Equipped With Magnetorheological Dampers, Simon Laflamme, Jerome J. Connor

Simon Laflamme

This paper proposes an adaptive neural network composed of Gaussian radial functions for mapping the behavior of civil structures controlled with magnetorheological dampers. The online adaptation takes into account the limited force output of the semi-active dampers using a sliding mode controller, as their reaction forces are state dependent. The structural response and the actual forces from the dampers are used to adapt the Gaussian network by tuning the radial function widths, centers, and weights. In order to accelerate convergence of the Gaussian radial function network during extraordinary external excitations, the learning rates are also adaptive. The proposed controller is …


Bcc-To-Hcp Transformation Pathways For Iron Versus Hydrostatic Pressure: Coupled Shuffle And Shear Modes, J. B. Liu, Duane D. Johnson Apr 2009

Bcc-To-Hcp Transformation Pathways For Iron Versus Hydrostatic Pressure: Coupled Shuffle And Shear Modes, J. B. Liu, Duane D. Johnson

Duane D. Johnson

Using density-functional theory, we calculate the potential-energy surface (PES), minimum-energy pathway (MEP), and transition state (TS) versus hydrostatic pressure σhyd for the reconstructive transformation in Fe from body-centered cubic (bcc) to hexagonal closed-packed (hcp). At fixed σhyd, the PES is described by coupled shear (ϵ) and shuffle (η) modes and is determined from structurally minimized hcp-bcc energy differences at a set of (η,ϵ). We fit the PES using symmetry-adapted polynomials, permitting the MEP to be found analytically. The MEP is continuous and fully explains the transformation and its associated magnetization and volume discontinuity at TS. We show that σhyd (while …


Children's Acceptance, Nutritional, And Instrumental Evaluations Of Whole Grain And Soluble Fiber Enriched Foods, A. Toma, M. B. Omary, L. F. Marquart, E. A. Arndt, Kurt A. Rosentrater, B. Burns-Whitmore, L. Kessler, K. Hwan, A. Sandoval, A. Sung Apr 2009

Children's Acceptance, Nutritional, And Instrumental Evaluations Of Whole Grain And Soluble Fiber Enriched Foods, A. Toma, M. B. Omary, L. F. Marquart, E. A. Arndt, Kurt A. Rosentrater, B. Burns-Whitmore, L. Kessler, K. Hwan, A. Sandoval, A. Sung

Kurt A. Rosentrater

The Dietary Guidelines for Americans 2005 report recommends 3 or more daily ounce-equivalents of whole grains (WG), and the FDA suggests consumption of 25 g of total dietary fiber (TDF) and 6 g of soluble fiber (SF) for a 2000-calorie diet. Efforts to increase the consumption of WG and SF among elementary school-aged children are needed. The objectives of this study were to examine the consumption of WG- and SF-enriched burritos and cookies among elementary school-aged children and to perform a quality evaluation of all products. Children in grades K to 6 from a local elementary school consumed control (CTR) …


Flowability Properties Of Commercial Distillers Dried Grains With Solubles (Ddgs), Rumela Bhadra, Kasiviswanathan Muthukumarappan, Kurt A. Rosentrater Mar 2009

Flowability Properties Of Commercial Distillers Dried Grains With Solubles (Ddgs), Rumela Bhadra, Kasiviswanathan Muthukumarappan, Kurt A. Rosentrater

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 United States. Carr and Jenike tests were performed and the …


Macroporous Silica Using A “Sticky” Stöber Process, Rebecca Cademartiri, Michael A. Brook, Robert Pelton, John D. Brennan Jan 2009

Macroporous Silica Using A “Sticky” Stöber Process, Rebecca Cademartiri, Michael A. Brook, Robert Pelton, John D. Brennan

Rebecca Cademartiri

The generation of macroporous silica structures using a sol–gel process generally requires the presence of high molecular weight, water-soluble polymers. We demonstrate that significantly lower molecular weight poly(ethylene glycol) (PEG) polymers can drive a particle aggregation process to generate macroporous silica. Compared to unfunctionalized PEGs (HO–PEG–HO, molecular weight > 10 000 g mol−1), PEG polymers with allyl (A–PEG–A) or silyl end groups (CH2)3Si(OEt)3 (Si–PEG–Si), with molecular weights of 2000 g mol−1 or greater, lead to monolithic macroporous structures derived from aggregates of nearly monodisperse particles. Lower molecular weight (less than 1000 g mol−1) allyl or silyl PEG, or hydroxy-terminated PEG–OH, lead …


Study Of A Nanoscale Water Cluster By Atomic Force Microscopy, Manhee Lee, Baekman Sung, Nicole N. Hashemi, Wonho Jhe Jan 2009

Study Of A Nanoscale Water Cluster By Atomic Force Microscopy, Manhee Lee, Baekman Sung, Nicole N. Hashemi, Wonho Jhe

Nastaran Hashemi

We present a novel method for investigating a nanometric cluster of water molecules, which includes the formation and manipulation of nanometric water, and the measurement of its mechanical properties. The atomic force microscope based on the quartz tuning-fork sensor is employed to form and manipulate the nanometric water, and the theoretical tool of amplitude-modulation atomic force microscopy is used to obtain the elasticity, viscosity and dissipation energy of it. With high vertical resolution less than [similar]0.1 nm and high force sensitivity of [similar]0.01 N m−1, this tool facilitates the stable formation and manipulation of a nano-water cluster ([similar]104 molecules) in …


The Development And Implementation Of A Nanotechnology Module Into A Large, Freshman Engineering Course, Vinod Lohani, Ganesh Balasubramanian, Ishwar Puri, Scott Case, Roop Mahajan Jan 2009

The Development And Implementation Of A Nanotechnology Module Into A Large, Freshman Engineering Course, Vinod Lohani, Ganesh Balasubramanian, Ishwar Puri, Scott Case, Roop Mahajan

Ganesh Balasubramanian

The development and implementation of a nanotechnology learning module into a freshman engineering course in Virginia Tech’s large engineering program is discussed. This module, a part of a spiral theory based nanotechnology option that will be implemented in the curriculum of the Engineering Science Mechanics (ESM) department at Virginia Tech, was piloted with ~180 freshmen in Spring ’08. The pilot included a prior knowledge survey, a 40-minute in-class presentation on nanotechnology, a hands-on module involving analysis of nanoscale images, plotting of force functions at atomic scale using LABVIEW, and a post-module survey. Students’ misconceptions, observed through the prior knowledge survey, …