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2014

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Articles 6631 - 6660 of 7238

Full-Text Articles in Engineering

Terahertz-Infrared Ellipsometer System, And Method Of Use, Craig H. Herzinger, Mathias M. Schubert, Tino Hofmann, Martin M. Liphardt, John A. Woollam Jan 2014

Terahertz-Infrared Ellipsometer System, And Method Of Use, Craig H. Herzinger, Mathias M. Schubert, Tino Hofmann, Martin M. Liphardt, John A. Woollam

Department of Electrical and Computer Engineering: Faculty Publications

The present invention relates to ellipsometer and polarimeter systems, and more particularly is an ellipsometer or polarimeter or the like system which operates in a frequency range between 300 GHz or lower and extending to higher than at least 1 Tera-hertz (THz), and preferably through the Infra-red (IR) range up Sh and his th. 100 THz, including: a Source Such as a backward wave oscillator, a Smith-Purcell cell; a free electron laser, or an FTIR source and a solid state device; and a detector Such as a Golay cell; abolometer or a solid state detector: and preferably including a polarization …

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Polymer Aggregation Correlated Transition From Schottky-Junction To Bulk Heterojunction Organic Solar Cells, Bin Yang, Zhengguo Xiao, Jinsong Huang Jan 2014

Polymer Aggregation Correlated Transition From Schottky-Junction To Bulk Heterojunction Organic Solar Cells, Bin Yang, Zhengguo Xiao, Jinsong Huang

Department of Mechanical and Materials Engineering: Faculty Publications

The fullerene-based organic Schottky-junction solar cells have recently attracted intensive research interest because of their unique electrical performance, such as significant photocurrent generation from excitons created in fullerenes and large open-circuit voltage (VOC) output induced by high Schottky-barrier height between the anode and the fullerene acceptor. This manuscript reports another remarkably appealing advantage that the fullerene-based Schottky-junction solar cells are more stable than the bulk heterojunction counterparts. The better stability is likely due to mitigative polymer photo-oxidation and/or little morphological change of active film in the aged Schottky-junction devices. The transition from Schottky-junction to bulk heterojunction appears at …

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Phase Transitions In Mechanically Milled Mn-Al-C Permanent Magnets, Michael J. Lucis, Timothy E. Prost, Xiujuan Jiang, Meiyu Wang, Jeffrey E. Shield Jan 2014

Phase Transitions In Mechanically Milled Mn-Al-C Permanent Magnets, Michael J. Lucis, Timothy E. Prost, Xiujuan Jiang, Meiyu Wang, Jeffrey E. Shield

Department of Mechanical and Materials Engineering: Faculty Publications

Mn-Al powders were prepared by rapid solidification followed by high-energy mechanical milling. The rapid solidification resulted in single-phase ε. The milling was performed in both the ε phase and the τ phase, with the τ-phase formation accomplished through a heat treatment at 500 °C for 10 min. For the ε-milled samples, the conversion of the ε to the τ phase was accomplished after milling via the same heat treatment. Mechanical milling induced a significant increase in coercivity in both cases, reaching 4.5 kOe and 4.1 kOe, respectively, followed by a decrease upon further milling. The increase in coercivity was the …

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Biomechanical Strain As A Trigger For Pore Formation In Schlemm’S Canal Endothelial Cells, Sietse T. Braakman, Ryan M. Pedrigi, A. Thomas Read, James A. E. Smith, W. Daniel Stamer, C. Ross Ethier, Darryl R. Overby Jan 2014

Biomechanical Strain As A Trigger For Pore Formation In Schlemm’S Canal Endothelial Cells, Sietse T. Braakman, Ryan M. Pedrigi, A. Thomas Read, James A. E. Smith, W. Daniel Stamer, C. Ross Ethier, Darryl R. Overby

Department of Mechanical and Materials Engineering: Faculty Publications

The bulk of aqueous humor passing through the conventional outflow pathway must cross the inner wall endothelium of Schlemm’s canal (SC), likely through micron-sized transendothelial pores. SC pore density is reduced in glaucoma, possibly contributing to obstructed aqueous humor outflow and elevated intraocular pressure (IOP). Little is known about the mechanisms of pore formation; however, pores are often observed near dome-like cellular outpouchings known as giant vacuoles (GVs) where significant biomechanical strain acts on SC cells. We hypothesize that biomechanical strain triggers pore formation in SC cells. To test this hypothesis, primary human SC cells were isolated from three non-glaucomatous …

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Altered Mechanobiology Of Schlemm’S Canal Endothelial Cells In Glaucoma, Darryl R. Overby, Enhua H. Zhou, Rocio Vargas-Pinto, Ryan M. Pedrigi, Rudolf Fuchshofer, Sietse T. Braakman, Ritika Gupta, Kristin M. Perkumas, Joesph M. Sherwood, Amir Vahabikashi, Quynh Dang, Jae Hun Kim, C. Ross Ethier, W. Daniel Stamer, Jeffrey J. Fredberg, Mark Johnson Jan 2014

Altered Mechanobiology Of Schlemm’S Canal Endothelial Cells In Glaucoma, Darryl R. Overby, Enhua H. Zhou, Rocio Vargas-Pinto, Ryan M. Pedrigi, Rudolf Fuchshofer, Sietse T. Braakman, Ritika Gupta, Kristin M. Perkumas, Joesph M. Sherwood, Amir Vahabikashi, Quynh Dang, Jae Hun Kim, C. Ross Ethier, W. Daniel Stamer, Jeffrey J. Fredberg, Mark Johnson

Department of Mechanical and Materials Engineering: Faculty Publications

Increased flow resistance is responsible for the elevated intraocular pressure characteristic of glaucoma, but the cause of this resistance increase is not known. We tested the hypothesis that altered biomechanical behavior of Schlemm’s canal (SC) cells contributes to this dysfunction. We used atomic force microscopy, optical magnetic twisting cytometry, and a unique cell perfusion apparatus to examine cultured endothelial cells isolated from the inner wall of SC of healthy and glaucomatous human eyes. Here we establish the existence of a reduced tendency for pore formation in the glaucomatous SC cell—likely accounting for increased outflow resistance—that positively correlates with elevated subcortical …

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A Decision Making Framework With Modflow-Fmp2 Via Optimization: Determining Trade-Offs In Crop Selection, K R. Fowler, E W. Jenkins, C Ostrove, J C. Chispell, M W. Farthing, M Parno Jan 2014

A Decision Making Framework With Modflow-Fmp2 Via Optimization: Determining Trade-Offs In Crop Selection, K R. Fowler, E W. Jenkins, C Ostrove, J C. Chispell, M W. Farthing, M Parno

United States Army Corps of Engineers, Omaha District

Farmers in regions experiencing water stress or drought conditions can struggle to balance their crop portfolios. Periods of low precipitation often lead to increased, unsustainable reliance on groundwatersupplied irrigation. As a result, regional water management agencies place limits on the amount of water which can be obtained from groundwater, requiring farmers to reduce acreage for more water-intensive crops or remove them from the portfolio entirely. Real-time decisions must be made by the farmer to ensure viability of their farming operation and reduce the impacts associated with limited water resources. Evolutionary algorithms, coupled with accurate, flexible, realistic simulation tools, are ideal …

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Effect Of Er Doping On The Structural And Magnetic Properties Of Cobalt-Ferrite, Sateesh Prathapani, M. Vinitha, Tanjore V. Jayaraman, D. Das Jan 2014

Effect Of Er Doping On The Structural And Magnetic Properties Of Cobalt-Ferrite, Sateesh Prathapani, M. Vinitha, Tanjore V. Jayaraman, D. Das

Department of Mechanical and Materials Engineering: Faculty Publications

Nanocrystalline particulates of Er doped cobalt-ferrites CoFe(2–x)ErxO4 (0 ≤ x ≤ 0.04), were synthesized, using sol-gel assisted autocombustion method. Co-, Fe-, and Er- nitrates were the oxidizers, and malic acid served as a fuel and chelating agent. Calcination (400–600 °C for 4h) of the precursor powders was followed by sintering (1000 °C for 4 h) and structural and magnetic characterization. X-ray diffraction confirmed the formation of single phase of spinel for the compositions x = 0, 0.01, and 0.02; and for higher compositions an additional orthoferrite phase formed along with the spinel phase. …

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Arising Applications Of Ferroelectric Materials In Photovoltaic Devices, Yongbo Yuan, Zhengguo Xiao, Bin Yang, Jinsong Huang Jan 2014

Arising Applications Of Ferroelectric Materials In Photovoltaic Devices, Yongbo Yuan, Zhengguo Xiao, Bin Yang, Jinsong Huang

Department of Mechanical and Materials Engineering: Faculty Publications

The ferroelectric-photovoltaic (FE-PV) device, in which a homogeneous ferroelectric material is used as a light absorbing layer, has been investigated during the past several decades with numerous ferroelectric oxides. The FE-PV effect is distinctly different from the typical photovoltaic (PV) effect in semiconductor p–n junctions in that the polarization electric field is the driving force for the photocurrent in FE-PV devices. In addition, the anomalous photovoltaic effect, in which the voltage output along the polarization direction can be significantly larger than the bandgap of the ferroelectric materials, has been frequently observed in FE-PV devices. However, a big challenge faced by …

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Extracting Continuum-Like Deformation And Stress From Molecular Dynamics Simulations, Lili Zhang, John Jasa, George Gazonas, Antoine Jerusalem, Mehrdad Negahban Jan 2014

Extracting Continuum-Like Deformation And Stress From Molecular Dynamics Simulations, Lili Zhang, John Jasa, George Gazonas, Antoine Jerusalem, Mehrdad Negahban

Department of Mechanical and Materials Engineering: Faculty Publications

We present methods that use results from molecular dynamics (MD) simulations to construct continuum parameters, such as deformation gradient and Cauchy stress, from all or any part of an MD system. These parameters are based on the idea of minimizing the difference between MD measures for deformation and traction and their continuum counterparts. The procedures should be applicable to non-equilibrium and inhomogeneous systems, and to any part of a system, such as a polymer chain. The resulting procedures provide methods to obtain first and higher order deformation gradients associated with any subset of the MD system, and associated expressions for …

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Practical Aspects Of Modern And Future Permanent Magnets, R.W. Mccallum, L. H. Lewis, Ralph Skomski, M. J. Kramer, I. E. Anderson Jan 2014

Practical Aspects Of Modern And Future Permanent Magnets, R.W. Mccallum, L. H. Lewis, Ralph Skomski, M. J. Kramer, I. E. Anderson

Ralph Skomski Publications

The mandate to reduce greenhouse gases will require highly efficient electric machines for both power generation and traction motor applications. Although permanent magnet electric machines utilizing Nd2Fe14B-based magnets provide obvious power-to-weight advantages over induction machines, the limited availability and high price of the rare earth (RE) metals make these machines less favorable. Of particular concern is the cost and supply criticality of Dy, a key RE element that is required to improve the high-temperature performance of Nd-based magnetic alloys for use in generators and traction motors. Alternatives to RE-based alloys do exist, but they currently lack the energy density necessary …

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Approximations To The Solution Of The Frank-Kamenetskii Equation In A Spherical Geometry, Moustafa A. Soliman Jan 2014

Approximations To The Solution Of The Frank-Kamenetskii Equation In A Spherical Geometry, Moustafa A. Soliman

Chemical Engineering

In this paper, an approximate analytical solution for Frank-Kamenetskii equation modeling a thermal explosion in a sphere, is obtained. The approximate solution is obtained by perturbation methods in terms of small and large distance parameter. The approximate solution is compared with the numerical solution obtained from an initial value problem formulation to the original boundary value problem. The approximate solution obtained is valid for all values of the distance parameter. For the original boundary value problem and for a given Frank-Kamenetskii parameter, a nonlinear algebraic equation needs to be solved to be able to apply the approximate solution.

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Development Of Nickel Oxide And Manganese Oxide Nanostructured Binary Modified Anodes For Methanol Electro-Oxidation, Ghada El-Nowihy Jan 2014

Development Of Nickel Oxide And Manganese Oxide Nanostructured Binary Modified Anodes For Methanol Electro-Oxidation, Ghada El-Nowihy

Chemical Engineering

In this investigation, a nanoparticle-based binary catalyst composed of nickel oxide (nano-NiOx) and manganese oxide (nano-MnOx), both were assembled on a platinum substrate, was developed for the direct methanol electro-oxidation (MO) in an alkaline medium. The morphological investigation was performed using field-emission SEM and revealed the electrodeposition of MnOx in a nanorod structure and NiOx in round-shaped nanospheres. The electrocatalytic activity of the modified electrodes towards MO depended critically on the order of deposition of the two oxides. The optimum electrocatalytic activity was obtained at the MnOx/NiOx/Pt electrode (in which nano-NiOx was directly electrodeposited onto the Pt surface followed by …

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Reuse Of The Product Obtained On Grinding Kiln Rollers In The Manufacture Of Ceramic Wall Tiles, Mai H. Roushdy, Shereen K. Amin, Marwa Mohamed, Magdi F. Abadir Jan 2014

Reuse Of The Product Obtained On Grinding Kiln Rollers In The Manufacture Of Ceramic Wall Tiles, Mai H. Roushdy, Shereen K. Amin, Marwa Mohamed, Magdi F. Abadir

Chemical Engineering

The production of ceramic tiles and to a lesser extent flat dinner ware and pottery is increasingly being done by firing in roller kilns. These kilns offer several advantages over conventional tunnel kilns: lower fuel consumption, computer controlled firing curves, low maintenance due to lack of kiln cars, rapid firing cycles of less than one hour and the possibility of shutting down the kiln on short notice.1 One recurrent problem in the operation of such kilns is the periodic need to grind the kiln rollers. These are usually fabricated from high alumina clays and are continuously contaminated by depositions of …

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Information In Biological Systems And The Fluctuation Theorem, Yaşar Demirel Jan 2014

Information In Biological Systems And The Fluctuation Theorem, Yaşar Demirel

Department of Chemical and Biomolecular Engineering: Faculty Publications

Some critical trends in information theory, its role in living systems and utilization in fluctuation theory are discussed. The mutual information of thermodynamic coupling is incorporated into the generalized fluctuation theorem by using information theory and nonequilibrium thermodynamics. Thermodynamically coupled dissipative structures in living systems are capable of degrading more energy, and processing complex information through developmental and environmental constraints. The generalized fluctuation theorem can quantify the hysteresis observed in the amount of the irreversible work in nonequilibrium regimes in the presence of information and thermodynamic coupling.

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Development And Testing Of An In-Stream Phosphorus Cycling Model For The Soil And Water Assessment Tool, Michael J. White, Daniel E. Storm, Aaron R. Mittelstet, Philip R. Busteed, Brian E. Haggard, Colleen Rossi Jan 2014

Development And Testing Of An In-Stream Phosphorus Cycling Model For The Soil And Water Assessment Tool, Michael J. White, Daniel E. Storm, Aaron R. Mittelstet, Philip R. Busteed, Brian E. Haggard, Colleen Rossi

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The Soil and Water Assessment Tool is widely used to predict the fate and transport of phosphorus (P) from the landscape through streams and rivers. The current in-stream P submodel may not be suitable for many stream systems, particularly those dominated by attached algae and those affected by point sources. In this research, we developed an alternative submodel based on the equilibrium P concentration concept coupled with a particulate scour and deposition model. This submodel was integrated with the SWAT model and applied to the Illinois River Watershed in Oklahoma, a basin influenced by waste water treatment plant discharges and …

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Simulation Supported Estimation Of End-To-End Transmission Parameters In Non-Viral Gene Delivery, Beata J. Wysocki, Tadeusz A. Wysocki, Timothy M. Martin, Angela K. Pannier Jan 2014

Simulation Supported Estimation Of End-To-End Transmission Parameters In Non-Viral Gene Delivery, Beata J. Wysocki, Tadeusz A. Wysocki, Timothy M. Martin, Angela K. Pannier

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Communications, in general, involve delivery of information from a source to a sink. At nano-scale, an example of a man-made communications involving interfacing with biological systems at intra-cellular level is non-viral gene delivery. From a telecommunications engineering perspective, important end-to-end parameters of such a system are: the endto- end delay, system capacity, and packet loss rate. There are neither known methods to estimate those parameters theoretically nor they are ready available from standard measurements. The paper provides estimates for those parameters based on the simulation of non-viral gene delivery system based on the queuing theory. The simulator used has been …

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Alginate/Silica Hybrid Materials For Immobilization Of Green Microalgae Chlorella Vulgaris For Cellbased Sensor Arrays, Angela K. Pannier, Ulrich Soltmann, Bettina Soltmann, Rolf Altenburger, Mechthild Schmitt-Jansen Jan 2014

Alginate/Silica Hybrid Materials For Immobilization Of Green Microalgae Chlorella Vulgaris For Cellbased Sensor Arrays, Angela K. Pannier, Ulrich Soltmann, Bettina Soltmann, Rolf Altenburger, Mechthild Schmitt-Jansen

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Thin layers and patterned dot arrays of sodium alginate containing living microalgal cells were deposited onto glass carriers which were subsequently gelled using amino-functionalized silica sol to obtain reinforced alginate hydrogels. The resulting alginate/silica hybrid materials showed improved stability in salt-containing solutions compared to alginate gels gelled by traditional methods using Ca2+-ions. Cell arrays were patterned by printing nanolitre-scale drops of sodium alginate/cell suspension using a noncontact micro-dosage system which allows the printing of solutions of high viscosity. Cultures of the green microalga Chlorella vulgaris were immobilized within the newly developed alginate/silica hydrogels in order to demonstrate the …

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In Vitro Development Of Preimplantation Porcine Embryos Using Alginate Hydrogels As A Three-Dimensional Extracellular Matrix, Catherine Sargus-Patino, Elane C. Wright, Sarah A. Plautz, Jeremy R. Miles, Jeff L. Vallet, Angela K. Pannier Jan 2014

In Vitro Development Of Preimplantation Porcine Embryos Using Alginate Hydrogels As A Three-Dimensional Extracellular Matrix, Catherine Sargus-Patino, Elane C. Wright, Sarah A. Plautz, Jeremy R. Miles, Jeff L. Vallet, Angela K. Pannier

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Between Days 10 and 12 of gestation, porcine embryos undergo a dramatic morphological change, known as elongation, with a corresponding increase in oestrogen production that triggers maternal recognition of pregnancy. Elongation deficiencies contribute to embryonic loss, but exact mechanisms of elongation are poorly understood due to the lack of an effective in vitro culture system. Our objective was to use alginate hydrogels as three-dimensional scaffolds that can mechanically support the in vitro development of preimplantation porcine embryos. White cross-bred gilts were bred at oestrus (Day 0) to Duroc boars and embryos were recovered on Days 9, 10 or 11 of …

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Nutrient Concentrations Of Runoff As Affected By The Diameter Of Unconsolidated Material From Feedlot Surfaces, John E. Gilley, Gregory Boone, David B. Marx Jan 2014

Nutrient Concentrations Of Runoff As Affected By The Diameter Of Unconsolidated Material From Feedlot Surfaces, John E. Gilley, Gregory Boone, David B. Marx

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Beef cattle feedlots contain unconsolidated material that accumulates on the feedlot surface during a feeding cycle. This study was conducted to measure the effects of varying diameters of unconsolidated surface material and varying flow rates on nutrient concentrations in runoff. Unconsolidated surface material with an average diameter of 4.76, 9.53, 19.1, or 47.5 mm and a composite sample with a 15.2 mm mean diameter were placed within 0.75 m wide × 4.0 m long plot areas. Flow was then introduced at the top of the plots in successive increments, and runoff samples for water quality analyses were obtained. Particle diameter …

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Dynamic Analysis Of Dna Nanoparticle Immobilization To Model Biomaterial Substrates Using Combinatorial Spectroscopic Ellipsometry And Quartz Crystal Microbalance With Dissipation, Tadas Kasputis, Alex Pieper, Mathias Schubert, Angela K. Pannier Jan 2014

Dynamic Analysis Of Dna Nanoparticle Immobilization To Model Biomaterial Substrates Using Combinatorial Spectroscopic Ellipsometry And Quartz Crystal Microbalance With Dissipation, Tadas Kasputis, Alex Pieper, Mathias Schubert, Angela K. Pannier

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Gene expression within cells can be altered through gene delivery approaches, which have tremendous potential for gene therapy, tissue engineering, and diagnostics. Substrate-mediated gene delivery describes the delivery of plasmid DNA or DNA complexed with nonviral vectors to cells from a surface, with the DNA immobilized to a substrate through specific or nonspecific interactions. In this work, DNA-nanoparticle (DNA–NP) adsorption to substrates is evaluated using combinatorial, in situ spectroscopic ellipsometry and quartz crystal microbalance with dissipation (SE/QCM-D), to evaluate the basic dynamic processes involved in the adsorption and immobilization of DNA–NP complexes to substrates. The concentration of DNA–NP solutions influences …

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Soybean Yield, Evapotranspiration, Water Productivity, And Soil Water Extraction Response To Subsurface Drip Irrigation And Fertigation, Suat Irmak, James E. Specht, Lameck O. Odhiambo, J. M. Rees, K. G. Cassman Jan 2014

Soybean Yield, Evapotranspiration, Water Productivity, And Soil Water Extraction Response To Subsurface Drip Irrigation And Fertigation, Suat Irmak, James E. Specht, Lameck O. Odhiambo, J. M. Rees, K. G. Cassman

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Soybean [Glycine max (L.) Merr.] yield, irrigation water use efficiency (IWUE), crop water use efficiency (CWUE), evapotranspiration water use efficiency (ETWUE), and soil water extraction response to eleven treatments of full, limited, or delayed irrigation versus a rainfed control were investigated using a subsurface drip irrigation (SDI) system at a research site in south-central Nebraska. The SDI system laterals were 0.40 m deep in every other row middle of 0.76 m spaced plant rows. Actual evapotranspiration (ETa) was quantified in all treatments and used to schedule irrigation events on a 100% ETa replacement basis in all but …

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Combined Qcm-D/Ge As A Tool To Characterize Stimuli-Responsive Swelling Of And Protein Adsorption On Polymer Brushes Grafted Onto 3d-Nanostructures, Meike Koenig, Tadas Kasputis, Daniel Schmidt, Keith B. Rodenhausen Jr., Klaus-Jochen Eichhorn, Angela K. Pannier, Mathias Schubert, Manfred Stamm, Petra Uhlmann Jan 2014

Combined Qcm-D/Ge As A Tool To Characterize Stimuli-Responsive Swelling Of And Protein Adsorption On Polymer Brushes Grafted Onto 3d-Nanostructures, Meike Koenig, Tadas Kasputis, Daniel Schmidt, Keith B. Rodenhausen Jr., Klaus-Jochen Eichhorn, Angela K. Pannier, Mathias Schubert, Manfred Stamm, Petra Uhlmann

Department of Agricultural and Biological Systems Engineering: Faculty Publications

A combined setup of quartz crystal microbalance and generalized ellipsometry can be used to comprehensively investigate complex functional coatings comprising stimuli-responsive polymer brushes and 3D nanostructures in a dynamic, noninvasive in situ measurement. While the quartz crystal microbalance detects the overall change in areal mass, for instance, during a swelling or adsorption process, the generalized ellipsometry data can be evaluated in terms of a layered model to distinguish between processes occurring within the intercolumnar space or on top of the anisotropic nanocolumns. Silicon films with anisotropic nanocolumnar morphology were prepared by the glancing angle deposition technique and further functionalized by …

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Parallel Synthesis Of Poly(Amino Ether)-Templated Plasmonic Nanoparticles For Transgene Delivery, James Ramos, Thrimoorthy Potta, Olivia Scheideler, Kaushal Rege Jan 2014

Parallel Synthesis Of Poly(Amino Ether)-Templated Plasmonic Nanoparticles For Transgene Delivery, James Ramos, Thrimoorthy Potta, Olivia Scheideler, Kaushal Rege

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Plasmonic nanoparticles have been increasingly investigated for numerous applications in medicine, sensing, and catalysis. In particular, gold nanoparticles have been investigated for separations, sensing, drug/nucleic acid delivery, and bioimaging. In addition, silver nanoparticles demonstrate antibacterial activity, resulting in potential application in treatments against microbial infections, burns, diabetic skin ulcers, and medical devices. Here, we describe the facile, parallel synthesis of both gold and silver nanoparticles using a small set of poly(amino ethers), or PAEs, derived from linear polyamines, under ambient conditions and in absence of additional reagents. The kinetics of nanoparticle formation were dependent on PAE concentration and chemical composition. …

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Surface-Enhanced Raman Spectral Biomarkers Correlate With Ankle Brachial Index And Characterize Leg Muscle Biochemical Composition Of Patients With Peripheral Arterial Disease, Kim Cluff, Abby M. Kelly, Panagiotis Koutakis, Xiang N. He, Xi Huang, Yongfeng Lu, Iraklis I. Pipinos, George P. Casale, Jeyamkondan Subbiah Jan 2014

Surface-Enhanced Raman Spectral Biomarkers Correlate With Ankle Brachial Index And Characterize Leg Muscle Biochemical Composition Of Patients With Peripheral Arterial Disease, Kim Cluff, Abby M. Kelly, Panagiotis Koutakis, Xiang N. He, Xi Huang, Yongfeng Lu, Iraklis I. Pipinos, George P. Casale, Jeyamkondan Subbiah

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Peripheral arterial disease (PAD) is characterized by atherosclerotic blockages of the arteries supplying the lower extremities, which cause a progressive accumulation of ischemic injury to the skeletal muscles of the lower limbs. This injury includes altered metabolic processes, damaged organelles, and compromised bioenergetics in the affected muscles. The objective of this study was to explore the association of Raman spectral signatures of muscle biochemistry with the severity of atherosclerosis in the legs as determined by the Ankle Brachial Index (ABI) and clinical presentation. We collected muscle biopsies from the gastrocnemius (calf muscle) of five patients with clinically diagnosed claudication, five …

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Water-Stable Three-Dimensional Ultrafine Fibrous Scaffolds From Keratin For Cartilage Tissue Engineering, Helan Xu, Shaobo Cai, Lan Xu, Yiqi Yang Jan 2014

Water-Stable Three-Dimensional Ultrafine Fibrous Scaffolds From Keratin For Cartilage Tissue Engineering, Helan Xu, Shaobo Cai, Lan Xu, Yiqi Yang

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Intrinsically water-stable scaffolds composed of ultrafine keratin fibers oriented randomly and evenly in three dimensions were electrospun for cartilage tissue engineering. Keratin has been recognized as a biomaterial that could substantially support the growth and development of multiple cell lines. Besides, three-dimensional (3D) ultrafine fibrous structures were preferred in tissue engineering due to their structural similarity to native extracellular matrices in soft tissues. Recently, we have developed a nontraditional approach to developing 3D fibrous scaffolds from alcohol-soluble corn protein, zein, and verified their structural advantages in tissue engineering. However, keratin with highly cross-linked molecular structures could not be readily dissolved …

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Intrinsically Water-Stable Keratin Nanoparticles And Their In Vivo Biodistribution For Targeted Delivery, Helan Xu, Zhen Shi, Narendra Reddy, Yiqi Yang Jan 2014

Intrinsically Water-Stable Keratin Nanoparticles And Their In Vivo Biodistribution For Targeted Delivery, Helan Xu, Zhen Shi, Narendra Reddy, Yiqi Yang

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Highly water-stable nanoparticles of around 70 nm and capable of distributing with high uptake in certain organs of mice were developed from feather keratin. Nanoparticles could provide novel veterinary diagnostics and therapeutics to boost efficiency in identification and treatment of livestock diseases to improve protein supply and ensure safety and quality of food. Nanoparticles could penetrate easily into cells and small capillaries, surpass detection of the immune system, and reach targeted organs because of their nanoscale sizes. Proteins with positive and negative charges and hydrophobic domains enable loading of various types of drugs and, hence, are advantageous over synthetic polymers …

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Organic Ferroelectric Evaporator With Substrate Cooling And In Situ Transport Capabilities, Keith Foreman, C. Labedz, M. Shearer, Shireen Adenwalla Jan 2014

Organic Ferroelectric Evaporator With Substrate Cooling And In Situ Transport Capabilities, Keith Foreman, C. Labedz, M. Shearer, Shireen Adenwalla

Shireen Adenwalla Papers

We report on the design, operation, and performance of a thermal evaporation chamber capable of evaporating organic thin films. Organic thin films are employed in a diverse range of devices and can provide insight into fundamental physical phenomena. However, growing organic thin films is often challenging and requires very specific deposition parameters. The chamber presented here is capable of cooling sample substrates to temperatures below 130 K and allows for the detachment of the sample from the cooling stage and in situ transport. This permits the use of multiple deposition techniques in separate, but connected, deposition chambers without breaking vacuum …

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Equipment Fragility Due To Shock Response, Christopher Y. Tuan Jan 2014

Equipment Fragility Due To Shock Response, Christopher Y. Tuan

Department of Civil and Environmental Engineering: Faculty Publications

Because of its simplicity, the shock response spectrum has become widely used as a means of describing the shock responses and fragilities of structures and equipment. This paper focuses on the drawbacks of using the shock response spectrum for defining equipment shock tolerance. A cantilever beam with a tip mass was used to model a hypothetical piece of equipment subjected to strong ground motion such as that caused by an explosion. The exact solution from a detailed modal analysis shows that multiple modes of response were excited. Contributions from higher modes can be more predominant than that from the fundamental …

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Numerical Simulations Of Dynamic Behavior Of Polyurea Toughened Steel Plates Under Impact Loading, Chien-Chung Chen, Daniel G. Linzell Jan 2014

Numerical Simulations Of Dynamic Behavior Of Polyurea Toughened Steel Plates Under Impact Loading, Chien-Chung Chen, Daniel G. Linzell

Department of Civil and Environmental Engineering: Faculty Publications

The objective of the work discussed herein is to develop a nonlinear 3D finite element model to simulate dynamic behavior of polyurea toughened steel plates under impact loading. Experimental and numerical work related to model development are presented. Material properties are incorporated into numerical models to account for strain-rate effects on the dynamic behavior of polyurea and steel. One bare steel plate and four polyurea toughened steel plates were tested under impact loading using a pendulum impact device. Displacement time-history data from experimental work was used to validate the numerical models. Details on material model construction, finite element model development, …

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Assessment Of Load Sharing Members In An Anti-Ram Bollard System, Scott Kinney, Daniel Linzell, Edward O'Hare Jan 2014

Assessment Of Load Sharing Members In An Anti-Ram Bollard System, Scott Kinney, Daniel Linzell, Edward O'Hare

Department of Civil and Environmental Engineering: Faculty Publications

Due to the increased frequency, scale, and danger of malicious attacks carried out by Vehicle Borne Improvised Explosive Devices (VBIEDs), anti-ram bollards have become a key element in the protection of critical structures. This study focused on the evaluation of above grade load sharing members in a steel anti-ram bollard system in an attempt to develop efficient load sharing mechanisms that improve the structure’s ability to resist vehicle impacts, while concurrently remaining aesthetically pleasing to the general public. A computational assessment was completed using calibrated LS-DYNA finite element models to determine if effective load sharing member configurations and designs could …

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