Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

133,816 Full-Text Articles 154,375 Authors 44,573,586 Downloads 284 Institutions

All Articles in Engineering

Faceted Search

133,816 full-text articles. Page 3665 of 3740.

Ellipsometric Study Of Single-Crystal Γ-Inse From 1.5 To 9.2 Ev, S. G. Choi, D. E. Aspnes, A. L. Fuchser, C. Martinez-Tomas, V. Muñoz Sanjosé, D. H. Levi 2010 National Renewable Energy Laboratory, Golden, Colorado 80401, USA

Ellipsometric Study Of Single-Crystal Γ-Inse From 1.5 To 9.2 Ev, S. G. Choi, D. E. Aspnes, A. L. Fuchser, C. Martinez-Tomas, V. Muñoz Sanjosé, D. H. Levi

US Department of Energy Publications

We report the component Ec of the pseudodielectric-function tensor <ε(E)> = <ε1(E)> + i< ε2(E)> of γ-phase single-crystal InSe, obtained from 1.5 to 9.2 eV by vacuum-ultraviolet spectroscopic ellipsometry with the sample at room temperature. Overlayer artifacts were reduced as far as possible by measuring fresh surfaces prepared by cleavage. Accurate critical-point energies of observed structures were obtained by a combined method of spectral analysis.


Linearized Theory Of Peridynamic States, S. A. Silling 2010 Sandia National Laboratories

Linearized Theory Of Peridynamic States, S. A. Silling

US Department of Energy Publications

A state-based peridynamic material model describes internal forces acting on a point in terms of the collective deformation of all the material within a neighborhood of the point. In this paper, the response of a state-based peridynamic material is investigated for a small deformation superposed on a large deformation. The appropriate notion of a small deformation restricts the relative displacement between points, but it does not involve the deformation gradient (which would be undefined on a crack). The material properties that govern the linearized material response are expressed in terms of a new quantity called the modulus state. This determines ...


Role Of Outer-Membrane Cytochromes Mtrc And Omca In The Biomineralization Of Ferrihydrite By Shewanella Oneidensis Mr-1, C. L. Reardon, Alice Dohnalkova, P. Nachimuthu, David Kennedy, D. A. Saffarini, B. W. Arey, L. Shi, Zheming Wang, D. Moore, J. S. Mclean, D. Moyles, M. J. Marshall, John M. Zachara, James K. Fredrickson, A. S. Beliaev 2010 Pacific Northwest National Laboratory

Role Of Outer-Membrane Cytochromes Mtrc And Omca In The Biomineralization Of Ferrihydrite By Shewanella Oneidensis Mr-1, C. L. Reardon, Alice Dohnalkova, P. Nachimuthu, David Kennedy, D. A. Saffarini, B. W. Arey, L. Shi, Zheming Wang, D. Moore, J. S. Mclean, D. Moyles, M. J. Marshall, John M. Zachara, James K. Fredrickson, A. S. Beliaev

US Department of Energy Publications

In an effort to improve the understanding of electron transfer mechanisms at the microbe–mineral interface, Shewanella oneidensis MR-1 mutants with in-frame deletions of outer-membrane cytochromes (OMCs), MtrC and OmcA, were characterized for the ability to reduce ferrihydrite (FH) using a suite of microscopic, spectroscopic, and biochemical techniques. Analysis of purified recombinant proteins demonstrated that both cytochromes undergo rapid electron exchange with FH in vitro with MtrC displaying faster transfer rates than OmcA. Immunomicroscopy with cytochrome-specific antibodies revealed that MtrC co-localizes with iron solids on the cell surface while OmcA exhibits a more diffuse distribution over the cell surface. After ...


Confinement Resonances In Photoionization Of Xe@C+60, A. L. D. Kilcoyne, A. Aguilar, A. Muller, S. Schippers, C. Cisneros, G. Alna’Washi, N. B. Aryal, K. K. Baral, D. A. Esteves, C. M. Thomas, R. A. Phaneuf 2010 Lawrence Berkeley National Laboratory

Confinement Resonances In Photoionization Of Xe@C+60, A. L. D. Kilcoyne, A. Aguilar, A. Muller, S. Schippers, C. Cisneros, G. Alna’Washi, N. B. Aryal, K. K. Baral, D. A. Esteves, C. M. Thomas, R. A. Phaneuf

US Department of Energy Publications

Experimental evidence is presented for confinement resonances associated with photoabsorption by a Xe atom in a C60 cage. The giant 4d resonance in photoionization of Xe is predicted to be redistributed into four components due to multipath interference of photoelectron waves reflected by the cage. The measurements were made in the photon energy range 60–150 eV by merging a beam of synchrotron radiation with a mass/charge selected Xe@C+60 ion beam. The phenomenon was observed in the Xe@C3+58 product ion channel.


Load-Locked Dc High Voltage Gaas Photogun With An Inverted-Geometry Ceramic Insulator, P. A. Adderley, J. Clark, J. Grames, J. Hansknecht, K. Surles-Law, D. Machie, M. Poelker, M. L. Stutzman, R. Suleiman 2010 Thomas Jefferson National Accelerator Facility

Load-Locked Dc High Voltage Gaas Photogun With An Inverted-Geometry Ceramic Insulator, P. A. Adderley, J. Clark, J. Grames, J. Hansknecht, K. Surles-Law, D. Machie, M. Poelker, M. L. Stutzman, R. Suleiman

US Department of Energy Publications

A new dc high voltage spin-polarized photoelectron gun has been constructed that employs a compact inverted-geometry ceramic insulator. Photogun performance at 100 kV bias voltage is summarized.

I. INTRODUCTION

All of the nuclear physics experiments conducted at the Continuous Electron Beam Accelerator Facility (CEBAF) at the Thomas Jefferson National Accelerator Facility (Jefferson Lab) receive electron beams from a dc high voltage spin-polarized GaAs photoemission gun. Since 1995, the year the first polarized electron source was installed at CEBAF [1], there have been four different photogun designs with each new gun an improvement over its predecessor. The most recent design employs ...


Persistent Organic Pollutants In Fish Tissue In The Mid-Continental Great Rivers Of The United States, Karen A. Blocksom, David M. Walters, Terri M. Jicha, James M. Lazorchak, Theodore R. Angradi, David W. Bolgrien 2010 U.S. Environmental Protection Agency

Persistent Organic Pollutants In Fish Tissue In The Mid-Continental Great Rivers Of The United States, Karen A. Blocksom, David M. Walters, Terri M. Jicha, James M. Lazorchak, Theodore R. Angradi, David W. Bolgrien

U.S. Environmental Protection Agency Papers

Great rivers of the central United States (Upper Mississippi, Missouri, and Ohio rivers) are valuable economic and cultural resources, yet until recently their ecological condition has not been well quantified. In 2004– 2005, as part of the Environmental Monitoring and Assessment Program for Great River Ecosystems (EMAPGRE), we measured legacy organochlorines (OCs) (pesticides and polychlorinated biphenyls, PCBs) and emerging compounds (polybrominated diphenyl ethers, PBDEs) in whole fish to estimate human and wildlife exposure risks from fish consumption. PCBs, PBDEs, chlordane, dieldrin and dichlorodiphenyltrichloroethane (DDT) were detected in most samples across all rivers, and hexachlorobenzene was detected in most Ohio River ...


Ab-10-019: Human Performance And Perception-Based Evaluations Of Indoor Noise Criteria For Rating Mechanical System Noise With Time-Varying Fluctuations (1322-Rp), Lily M. Wang, Cathleen C. Novak 2010 University of Nebraska - Lincoln

Ab-10-019: Human Performance And Perception-Based Evaluations Of Indoor Noise Criteria For Rating Mechanical System Noise With Time-Varying Fluctuations (1322-Rp), Lily M. Wang, Cathleen C. Novak

Architectural Engineering -- Faculty Publications

The goal of this study was to investigate the effects of noise from building mechanical systems with time-varying fluctuations on human task performance and perception, and to determine how well current indoor noise rating methods account for this performance and perception. Six different noise conditions with varying degrees of time-varying fluctuations, many focused in the low frequency rumble region, were reproduced in an office-like setting. Thirty participants were asked to complete typing, grammatical reasoning, and math tasks plus subjective questionnaires, while being exposed for approximately one hour to each noise condition. Results show that the noise conditions with higher sound ...


The Effects Of Bleedarrest, Celox, And Traumadex On Hemorrhage Control In A Porcine Model, Brian Gegel, James Burgert, Brian Cooley, Jacob MacGregor, Jules Myers, Sean Calder, Ralph Luellen, Michael Loughren, Don Johnson 2010 Brooke Army Medical Center

The Effects Of Bleedarrest, Celox, And Traumadex On Hemorrhage Control In A Porcine Model, Brian Gegel, James Burgert, Brian Cooley, Jacob Macgregor, Jules Myers, Sean Calder, Ralph Luellen, Michael Loughren, Don Johnson

US Army Research

Background

Hemorrhage is the second leading cause of death in civilian trauma and the leading cause of preventable death in military trauma. The purpose
of this study was to examine the effectiveness of three hemostatic agents: BleedArrest, TraumaDex, and Celox.

Materials and Methods

This was a prospective, experimental study using male Yorkshire swine. The pigs (n = 5 per group) were randomly assigned to one of the following: BleedArrest, TraumaDex, Celox, or control. To simulate a trauma injury, the investigators generated a complex groin injury with transection of the femoral artery and vein in all pigs. After 1 min of uncontrolled ...


Genomics And Proteomics In Chemical Warfare Agent Research: Recent Studies And Future Applications, Patrick A. Everly, James F. Dillman 2010 US Army Medical Research Institute of Chemical Defense

Genomics And Proteomics In Chemical Warfare Agent Research: Recent Studies And Future Applications, Patrick A. Everly, James F. Dillman

US Army Research

Medical research on the effects of chemical warfare agents (CWAs) has been ongoing for nearly 100 years, yet these agents continue to pose a serious threat to deployed military forces and civilian populations. CWAs are extremely toxic, relatively inexpensive, and easy to produce, making them a legitimate weapon of choice for terrorist organizations. While the mechanisms of action for manyCWAshave been known for years, questions about their molecular effects following acute and chronic exposure remain largely unanswered. Global approaches that can pinpoint which cellular pathways are altered in response to CWAs and characterize long-term toxicity have not been widely used ...


Activity Of Topical Antimicrobial Agents Against Multidrug-Resistant Bacteria Recovered From Burn Patients, Jessie S. Glasser, Charles H. Guymon, Katrin Mende, Steven E. Wolf, Duane R. Hospenthal, Clinton K. Murray 2010 San Antonio Military Medical Center

Activity Of Topical Antimicrobial Agents Against Multidrug-Resistant Bacteria Recovered From Burn Patients, Jessie S. Glasser, Charles H. Guymon, Katrin Mende, Steven E. Wolf, Duane R. Hospenthal, Clinton K. Murray

US Army Research

Background:

Topical antimicrobials are employed for prophylaxis and treatment of burn
wound infections despite no established susceptibility breakpoints, which are becoming vital in an era of multidrug-resistant (MDR) bacteria. We compared two methods of determining topical antimicrobial susceptibilities.

Methods:

Isolates of Pseudomonas aeruginosa, methicillin-resistant Staphylococcus aureus (MRSA), extended spectrum beta-lactamase (ESBL) producing Klebsiella pneumoniae, and Acinetobacter baumanii-calcoaceticus (ABC) from burn patients were tested using broth microdilution and agar well diffusion to determine minimum inhibitory concentrations (MICs) and zones of inhibition (ZI). Isolates had systemic antibiotic resistance and clonality determined. MDR included resistance to antibiotics in three or more classes.

Results ...


Effects Of The Heet Garment In The Prevention Of Hypothermia In A Porcine Model, Don Johnson, Brian Gegel, James Burgert, Geoffrey W, Duncklee, Ricci R. Robinson, Eric J. Lewis, Paul M. Crum, William Kuhns, Daniel Moore, Scott O'Brien, Joel Elliott, Jason Washington, John Boyle, Dale Seigler 2010 US Army Graduate Program in Anesthesia Nursing

Effects Of The Heet Garment In The Prevention Of Hypothermia In A Porcine Model, Don Johnson, Brian Gegel, James Burgert, Geoffrey W, Duncklee, Ricci R. Robinson, Eric J. Lewis, Paul M. Crum, William Kuhns, Daniel Moore, Scott O'Brien, Joel Elliott, Jason Washington, John Boyle, Dale Seigler

US Army Research

Background

Hypothermia is a common battlefield trauma occurrence. This study compared the effectiveness of the hypothermia, environmental, exposure, and trauma (HEET) garment (Trident Industries, Beaufort, SC) with and without thermal inserts with a control group of two wool blankets in the prevention of hypothermia in a treated hypovolemic porcine model.

Materials and methods

Five female swine (Sus scrofa-Yorkshire cross) were assigned to each of three
groups: HEET with thermal inserts (n=5); HEET without thermal inserts (n=5); or control (n=5). After the animals were anesthetized and stabilized for 30min, the swine were hemorrhaged to a mean arterial pressure ...


Socio-Demographic And Drug Use Factors Associated With Hiv-1 Recombinants And Dual Infections In Northern Thai Drug Users: Associations Of Risk With Genetic Complexity, G. H. Kijak, C. Beyrer, S. Tovanabutra, T. Sripaipan, V. Suriyanon, N. Moqueet, E. Sanders-Buell, P. Saokhieo, U. Timpan, J. Jittiwutikarn, M. L. Robb, D. L. Birx, D. D. Celentano, F. E. McCutchan 2010 US Military HIV Research Program

Socio-Demographic And Drug Use Factors Associated With Hiv-1 Recombinants And Dual Infections In Northern Thai Drug Users: Associations Of Risk With Genetic Complexity, G. H. Kijak, C. Beyrer, S. Tovanabutra, T. Sripaipan, V. Suriyanon, N. Moqueet, E. Sanders-Buell, P. Saokhieo, U. Timpan, J. Jittiwutikarn, M. L. Robb, D. L. Birx, D. D. Celentano, F. E. Mccutchan

US Army Research

Background:

Dual infection with diverse HIV strains can foster the emergence of recombinants. The resulting increase in viral genetic diversity is a major challenge for vaccine development HIV treatment. In this study we aim to investigate the socio demographic factors associated with an increasing level of genetic diversity among HIV strains in a population of drug-users in Northern Thailand.

Methods:

From 1999 through 2000, 2231 volunteers were enrolled in the Opiate- Users Research in Chiang Mai, Thailand. HIV subtype analysis was conducted among those HIV-1 seropositive (n = 347) using a multi-region hybridization assay. Social and demographic variables were assessed using ...


Multiscale Modeling Of The Impact Of Textile Fabrics Based On Hybrid Element Analysis, Gaurav Nilakantan, Michael Keefe, Travis A. Bogetti, John W. Gillespie Jr. 2010 University of Delaware

Multiscale Modeling Of The Impact Of Textile Fabrics Based On Hybrid Element Analysis, Gaurav Nilakantan, Michael Keefe, Travis A. Bogetti, John W. Gillespie Jr.

US Army Research

In this work, a multi scale modeling approach has been developed to simulate the impact of woven fabrics using a finite element (FE) analysis. A yarn level of resolution is used in the model. This approach, referred to as the hybrid element analysis (HEA) is based on decreasing the complexity of the finite element model with distance away from the impact zone based on the multiscale nature of the fabric architecture and the physics of the impact event. Solid elements are used to discretize the yarns around the impact region, which transition to shell elements in the surrounding region. A ...


Current Us Military Operations And Implications For Military Surgical Training, Joshua A. Tyler, Kevin S. Clive, Christopher E. White, Alec C. Beekley, Lorne H. Blackbourne 2010 Brooke Army Medical Center

Current Us Military Operations And Implications For Military Surgical Training, Joshua A. Tyler, Kevin S. Clive, Christopher E. White, Alec C. Beekley, Lorne H. Blackbourne

US Army Research

BACKGROUND:

Since 2001, US military surgeons have deployed frequently, with many surgeons deploying within 1 year of graduating residency. The purpose of this study was to evaluate readiness of recent graduates to manage combat-related injuries and to make recommendations for improvements in training military surgeons.

STUDY DESIGN:

We reviewed casualties treated at the 31st Combat Support Hospital in Baghdad from December 2003 to November 2004.We identified 3,426 wounded patients; of these, 2,648 (77.3%) required an operative procedure. There were 2,788 patients (81.4%) who sustained penetrating injuries. The most common procedures performed were debridement ...


Impact Of Woven Fabric: Experiments And Mesostructure-Based Continuum-Level Simulations, Ethan M. Parsons, Tusit Weerasooriya, Sai Sarva, Simona Socrate 2010 Massachusetts Institute of Technology

Impact Of Woven Fabric: Experiments And Mesostructure-Based Continuum-Level Simulations, Ethan M. Parsons, Tusit Weerasooriya, Sai Sarva, Simona Socrate

US Army Research

Woven fabric is an increasingly important component of many defense and commercial systems, including deployable structures, restraint systems, numerous forms of protective armor, and a variety of structural applications where it serves as the reinforcement phase of composite materials. With the prevalence of these systems and the desire to explore new applications, acomprehensive, computationally efficient model for the deformation of woven fabrics is needed. However, modeling woven fabrics is difficult due, inparticular, to the need to simulate the response both at the scale of the entire fabric and at the meso-level, the scale of the yarns that compose the weave ...


Monotonic And Cyclic Short Beam Shear Response Of 3d Woven Composites, T. R. Walter, G. Subhash, University of Florida, C. F. Yen 2010 University of Florida

Monotonic And Cyclic Short Beam Shear Response Of 3d Woven Composites, T. R. Walter, G. Subhash, University Of Florida, C. F. Yen

US Army Research

Monotonic, multi-step and cyclic short beam shear tests were conducted on 2D and 3D woven composites. The test results were used to determine the effect of z-yarns on the inter-laminar shear strength as well as the multi-loading behavior. The presence of z-yarns was found to affect not only the inter-laminar shear strength of the composite but also the behavior of the composite beyond the elastic limit. Microscopic examination of the damaged specimens revealed large delamination cracks in 2D woven composites while delamination cracks were hindered by z-yarns in 3D composites. This crack arrest phenomena resulted in a reduction in inter-laminar ...


Noise Propagation Through Open Windows Of Finite Depth Into An Enclosure, Caleb Sieck, Siu-Kit Lau 2010 University of Nebraska-Lincoln

Noise Propagation Through Open Windows Of Finite Depth Into An Enclosure, Caleb Sieck, Siu-Kit Lau

Architectural Engineering -- Faculty Publications

Predicting the insertion loss of an opening backed with an enclosed space is important for building noise control. Recent research in sound transmission through apertures of finite depth in infinite rigid baffles has included the effects of propagating and evanescent modes within the aperture in order to extend models to higher frequencies. The present study extends the model to the case of the aperture backed by a cavity as opposed to sound radiating into half-space. The role of coupling between the aperture modes, radiation modes, and cavity modes in the transmission was investigated. The results were compared to those of ...


Nontuberculous Mycobacterium Infection In A Burn Icu Patient, Joseph M. Boyer, Peter J. Blatz, Kevin S. Akers, Jason F. Okulicz, Kevin K. Chung, Evan M. Rentz, Duane R. Hospenthal, Clinton K. Murray 2010 San Antonio Military Medical Center (SAMMC)

Nontuberculous Mycobacterium Infection In A Burn Icu Patient, Joseph M. Boyer, Peter J. Blatz, Kevin S. Akers, Jason F. Okulicz, Kevin K. Chung, Evan M. Rentz, Duane R. Hospenthal, Clinton K. Murray

US Army Research

Infection is a leading cause of mortality in burn patients, typically due to bacterial pathogens such as Staphylococcus aureus and Pseudomonas aeruginosa, less commonly fungi, and possibly viruses. In non-burn patients with underlying pulmonary or cutaneous disease, nontuberculous mycobacteria (NTM) have become an increasingly recognized cause of infection, especially in patients who are immunocompromised. Patients with severe burns might have higher rates of NTM infections due to inherent risks associated with the burn injury: compromised skin integrity, immunocompromised state, inhalation injury, and frequent use of indwelling vascular catheters. To date there have been no reports describing the incidence of mycobacterial ...


Structure–Property Relations Of Cyclic Damage In A Wrought Magnesium Alloy, J. D. Bernard, J. B. Jordon, M. F. Horstemeyer, H. El Kadiri, J. Baird, Dabid Lamb, Alan A. Luo 2010 Mississippi State University

Structure–Property Relations Of Cyclic Damage In A Wrought Magnesium Alloy, J. D. Bernard, J. B. Jordon, M. F. Horstemeyer, H. El Kadiri, J. Baird, Dabid Lamb, Alan A. Luo

US Army Research

The fatigue properties of an extruded Mg–3Al–0Mn magnesium alloy component were evaluated experimentally. Fully reversed, strain control fatigue tests were conducted on specimens extracted from regions with a varying grain size and texture. Scanning electron microscopy was employed to establish structure–property relations between microstructure and cyclic damage. Relations were drawn between microstructural features such as particle size, grain size, initial Taylor factor and the number of cycles to failure.


Study Of Strawberry Flavored Milk Under Pulsed Electric Field Processing, Daniela Bermúdez-Aguirre, Jaime A. Yáñez, C. Patrick Dunne, Neal M. Davies, Gustavo V. Barbosa-Cánovas 2010 Washington State University

Study Of Strawberry Flavored Milk Under Pulsed Electric Field Processing, Daniela Bermúdez-Aguirre, Jaime A. Yáñez, C. Patrick Dunne, Neal M. Davies, Gustavo V. Barbosa-Cánovas

US Army Research

Few studies exist on flavored milk processed by pulsed electric fields (PEF). The main concern is product stability. This study aimed to analyze the degradation of coloring agent Allura Red in strawberry milk under PEF. Four systems were tested containing Allura Red: two commercial milks and two model systems. PEF conditions were 40 kV/cm, 48 pulses (2.5 μs), and 55 °C; coloring agent was quantified via RP-HPLC. After processing, only minor changes were observed in color, Allura Red concentration, and pH. During storage (32 d) at refrigerated conditions (4 °C) commercial samples maintained pH above 6. Model systems ...


Digital Commons powered by bepress