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Iowa State University

2012

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Articles 31 - 42 of 42

Full-Text Articles in Engineering

Ultrasound-Assisted Synthesis Of Mesoporous Β-Ni(Oh)2 And Nio Nano-Sheets Using Ionic Liquids, Tarek Alammar, Osama Shekhah, Jonas Wohlgemuth, Anja V. Mudring Jan 2012

Ultrasound-Assisted Synthesis Of Mesoporous Β-Ni(Oh)2 And Nio Nano-Sheets Using Ionic Liquids, Tarek Alammar, Osama Shekhah, Jonas Wohlgemuth, Anja V. Mudring

Anja V. Mudring

Via a facile ultrasound synthesis from nickel acetate and sodium hydroxide with ionic liquids as the solvent and template it is possible to obtain nano-β-Ni(OH)2 of various dimensionalities depending on the reaction conditions with the ionic liquid (IL) being the most important factor. Scanning electron microscopy (SEM) imaging showed β-Ni(OH)2 to form as nanosheets, nanorods and nanospheres depending on the IL. ILs with strong to moderate hydrogen bonding capability like [C3mimOH][Tf2N] (1-(3-hydroxypropyl)-3-methylimidazolium bis(trifluoromethanesulfonylamide)), [C4mim][Tf2N] (1-butyl-3-methylimidazolium bis(trifluoromethanesulfonylamide)) and [Edimim][Tf2N] (1-ethyl-2,3-diemethylimidazolium bis(trifluoromethanesulfonylamide)) lead to the formation of nanosheets whilst [Py4][Tf2N] (butyl-pyridinium bis(trifluoromethanesulfonylamide)) leads to nanoparticles and [N1888][Tf2N] (methyltrioctylammonium bis(trifluoromethanesulfonylamide)) to nanorods. Subsequent …


Evaluation Of Eddy-Current Probe Signals Due To Cracks In Fastener Holes, John R. Bowler, Theodoros P. Theodoulidis, Hui Xie, Yuan Ji Jan 2012

Evaluation Of Eddy-Current Probe Signals Due To Cracks In Fastener Holes, John R. Bowler, Theodoros P. Theodoulidis, Hui Xie, Yuan Ji

John R. Bowler

Cracks in conductors are detected through changes in the impedance of a coil that induces current in the material. In order to gain insight into the physics of the inspection, we have developed a theoretical and computational model that predicts the signals due to cracks in circular cylindrical holes using a boundary element calculation. In formulating the problem, the electromagnetic field is decomposed into transverse electric and transverse magnetic scalar modes. The effect of a planar crack in an electromagnetic field is represented by an electric current dipole layer orientated normal to the crack surface. The dipole density is determined …


Analysis Of Arc-Electrode Capacitive Sensors For Characterization Of Dielectric Cylindrical Rods, Tianming Chen, Nicola Bowler, John R. Bowler Jan 2012

Analysis Of Arc-Electrode Capacitive Sensors For Characterization Of Dielectric Cylindrical Rods, Tianming Chen, Nicola Bowler, John R. Bowler

John R. Bowler

An arc-electrode capacitive sensor has been developed for quantitative characterization of permittivity of cylindrical dielectric rods. The material property of the cylindrical test piece can be inversely determined from the sensor output capacitance based on a theoretical model. For the modeling process, the electrostatic Green’s function due to a point source exterior to a dielectric rod is derived. The sensor output capacitance is numerically calculated using the method of moments (MoM), in which the integral equation is set up based on the electrostatic Green’s function. Numerical calculations on sensor configuration optimization are performed. Calculations also demonstrate the quantitative relationship between …


Materials For Diabetes Therapeutics, Kaitlin M. Bratlie, Roger L. York, Michael A. Invernale, Robert Langer, Daniel G. Anderson Jan 2012

Materials For Diabetes Therapeutics, Kaitlin M. Bratlie, Roger L. York, Michael A. Invernale, Robert Langer, Daniel G. Anderson

Kaitlin M. Bratlie

This review is focused on the materials and methods used to fabricate closedloop systems for type 1 diabetes therapy. Herein, we give a brief overview of current methods used for patient care and discuss two types of possible treatments and the materials used for these therapies-(i) artificial pancreases, comprised of insulin producing cells embedded in a polymeric biomaterial, and (ii) totally synthetic pancreases formulated by integrating continuous glucose monitors with controlled insulin release through degradable polymers and glucose-responsive polymer systems. Both the artificial and the completely synthetic pancreas have two major design requirements: the device must be both biocompatible and …


Nutritional Composition And Use Of Common Carp Muscle In Yellow Perch Diets, Travis W. Schaeffer, Matthew J. Hennen, Michael L. Brown, Kurt A. Rosentrater Jan 2012

Nutritional Composition And Use Of Common Carp Muscle In Yellow Perch Diets, Travis W. Schaeffer, Matthew J. Hennen, Michael L. Brown, Kurt A. Rosentrater

Kurt A. Rosentrater

High market demand for marine fish meals coupled with increasing costs and questionable sustainability of wild stocks have led researchers to investigate a variety of alternative plant and animal protein sources for aquaculture feeds. Our objective was to evaluate the use of common carp Cyprinus carpio, a locally abundant, nonnative fish species, to offset the cost of marine fish meal in fish feed. We completed analyses of common carp whole muscle, formulated diets containing combinations of carp and Gulf menhaden Brevoortia patronus fish meal, and then evaluated test diets in a feeding trial with yellow perch Perca flavescens. Composition (dry …


Overview Of Fuel Ethanol Production And Distillers Grains, Kurt A. Rosentrater Jan 2012

Overview Of Fuel Ethanol Production And Distillers Grains, Kurt A. Rosentrater

Kurt A. Rosentrater

Modern societies face many challenges, including growing populations, increased demands for food, clothing, housing, consumer goods, and the concomitant raw materials required to produce all of these. Additionally, there is a growing need for energy, which is most easily met by use of fossil fuels (e.g., coal, natural gas, and petroleum). In 2008, the overall U.S. demand for energy was 99.3 x 1015 Btu (1.05 x 1014 MJ); 84% of this was supplied by fossil sources (U.S. EIA, 2009). Transportation fuels accounted for 28% of all energy consumed during this time, and nearly 97% of this came from fossil sources. …


Manufacturing Of Fuel Ethanol And Distillers Grains—Current And Evolving Processes, Kurt A. Rosentrater, Klein Ileleji, David B. Johnson Jan 2012

Manufacturing Of Fuel Ethanol And Distillers Grains—Current And Evolving Processes, Kurt A. Rosentrater, Klein Ileleji, David B. Johnson

Kurt A. Rosentrater

Before examining all of the different possible uses of distillers dried grains with solubles (DDGS), a discussion regarding ethanol and DDGS production methods is warranted. This chapter will cover current production processes and some of the new practices that have been developed and are being adopted at plants, including front-end fractionation and back-end fractionation. Additionally, standard coproduct definitions will be discussed, as they govern the marketing and sales of these materials.


Dispersion Of Alkyl-Chain-Functionalized Reduced Graphene Oxide Sheets In Nonpolar Solvents, Jean-Philippe Tessonnier, Mark A. Barteau Jan 2012

Dispersion Of Alkyl-Chain-Functionalized Reduced Graphene Oxide Sheets In Nonpolar Solvents, Jean-Philippe Tessonnier, Mark A. Barteau

Jean-Philippe Tessonnier

Alkyl chains were grafted onto reduced graphene oxide sheets to allow their dispersion in toluene, a common and representative nonpolar solvent. The grafting occurred on a variety of oxygen-containing functionalities already present on reduced graphene oxide, such as hydroxyl and epoxide groups. The structure and the defect density of the sheets were not significantly altered during the synthesis. When dispersed in water-toluene mixtures, phase transfer from the aqueous to the organic phase was observed upon grafting. In addition, the dry powder obtained readily disperses in common organic solvents without the assistance of any sonication treatment.


Labeling And Monitoring The Distribution Of Anchoring Sites On Functionalized Cnts By Atomic Layer Deposition, Catherine Marichy, Jean-Philippe Tessonnier, Marta C. Ferro, Kyeong-Hwan Lee, Robert Schlogl, Nicola Pinna, Marc-Georg Willinger Jan 2012

Labeling And Monitoring The Distribution Of Anchoring Sites On Functionalized Cnts By Atomic Layer Deposition, Catherine Marichy, Jean-Philippe Tessonnier, Marta C. Ferro, Kyeong-Hwan Lee, Robert Schlogl, Nicola Pinna, Marc-Georg Willinger

Jean-Philippe Tessonnier

The chemical inertness of graphite and, in the case of tubes, of rolled up few layer graphene sheets, requires some degree of "defect engineering" for the fabrication of carbon based heterostructured materials. It is shown that atomic layer deposition provides a means to specifically label anchoring sites and can be used to characterize the surface functionality of differently treated carbon nanotubes. Direct observation of deposited titania by analytical transmission electron microscopy reveals the location and density of anchoring sites as well as structure related concentrations of functional groups on the surface of the tubes. Controlled functionalization of the tubes therefore …


Alternative Protein Sources For Aquaculture Feeds, Ferouz Y. Ayadi, Kurt A. Rosentrater, Kasiviswanathan Muthukumarappan Jan 2012

Alternative Protein Sources For Aquaculture Feeds, Ferouz Y. Ayadi, Kurt A. Rosentrater, Kasiviswanathan Muthukumarappan

Kurt A. Rosentrater

With a global seafood production of about 51.7 million ton in 2006 and an annual growth rate of 6.9% from 1970-2006, aquaculture is one of the fastest growing sectors in the food industry. Feed represents 40-70% of operating costs for aquaculture operations. Fish diets typically contain between 20 and 55% crude protein, depending on the fish species. High quantities of fish meal are commonly used in these feeds to supply fish with essential proteins, amino acids and fatty acids. However, during the last 3 years prices for fish meal have remained above $1000 ton-1 and have even approached $2000 ton-1 …


Surface Roughness And Diametral Consistency Of Holes Drilled Into Ddgs/Phenolic Resin Blends, J. W. Shanafield, A. W. Otieno, R. A. Tatara, D. J. Schroeder, Kurt A. Rosentrater Jan 2012

Surface Roughness And Diametral Consistency Of Holes Drilled Into Ddgs/Phenolic Resin Blends, J. W. Shanafield, A. W. Otieno, R. A. Tatara, D. J. Schroeder, Kurt A. Rosentrater

Kurt A. Rosentrater

In this study, corn-based distillers dried grains with solubles (DDGS) has been utilized as a filler and blended with phenolic resin. The blends were compression molded into rectangular test specimens, into which holes have been machined using a standard 9.52 mm (3/8 in) diameter, two-fluted twist drill. A series of tests was then conducted to examine the effects of DDGS content, cutting speed, and feed rate upon the surface finish (roughness) of the interior hole slot, as well as the consistency of the drilled hole diameter. DDGS content was 0, 25, 50, and 75%, by weight. Cutting speed was 17, …


Toward A Scientific Understanding Of Ddgs, Keshun Liu, Kurt A. Rosentrater Jan 2012

Toward A Scientific Understanding Of Ddgs, Keshun Liu, Kurt A. Rosentrater

Kurt A. Rosentrater

Recently, many people have asked what the fuel ethanol industry is going to do about the growing piles of nonfermented leftovers. Actually this question has been around for quite some time. As early as the 1940s, one report stated that "Grain distillers have developed equipment and an attractive market for their recovered grains" (Boruff, 1947), while another report described that "Distillers are recovering, drying, and marketing their destarched grain stillage as distillers dried grains and dried solubles" (Boruff, 1952). So it appears that a viable solution had already been developed as far back as the 1940s. And by the early …