Engineering Commons^™

Managing Risks Associated With The Jbcc(Principal Building Agreement) From Thesouth African Contractor’S Perspective, Ayman Ahmed Ezzat Othman, Nishani Harinarain

Architectural Engineering

Construction is a complex and risky business. It is a time-consuming process involving a multitude of organisations with different objectives and skills. In addition, increasing client expectations coupled with the technological development of materials and equipment made the construction industry subject to more risks than any other industry. Contracts are essential tools for organising the relationship between involved parties and managing associated risk. For years the South African construction industry had a very poor reputation in managing construction risks. In order to improve the image of the South African construction industry and to assist contractors to develop their proper risk …

Modelling Behavioural Antecedents Of Inter-Firm Linkages In The Irish Road Freight Industry: An Application Of The Theory Of Planned Behaviour, Eoin Plant

Doctoral

The Irish road haulage industry exhibits a structure dominated by singlevehicle owner-managed operators. This has implications for the Irish economy through reduced efficiency. It is crucial that Ireland’s transport policies sustain its trade-dependent economy and this study can help inform those policies. The European Union has made a commitment to promoting sustainable mobility through advanced transport logistics. One of the principal areas not previously addressed is that of barriers to ollaboration. This thesis initially examines economies of scale within the road freight industry and argues that collaborative networks can aid sustainable transport and increase efficiencies in logistics. It addresses the …

Egypt's Information Society Strategy: A Critical Lexicography, Neil Mcbride, Bernd Carsten Stahl

Journal of International Technology and Information Management

The development of ICT policies within developing countries in the past ten years has opened up a new area for study. These documents chart the ambitions of the countries for the use of ICT to promote rapid development. As such they are intercultural documents, developing at the interface between the culture of the country and western economic culture. This paper develops a critical approach to understanding these documents and studying their message. The approach involves the preparation of a critical dictionary which identifies relevant terms within the ICT policy document and reflects on their multiple meanings. The approach was applied …

Usability Investigation Of E-Business Web-Based Forms, Gerald V. Post, Albert Kagan, Betsy Page Sigman

Journal of International Technology and Information Management

Usability on Web sites is critical because almost no training is provided for users on commercial sites. Instead, Web design relies on standards and consistency across sites. Traditional usability results indicated that computer forms should follow paper-based forms. Yet, Web paradigms have evolved that are quite different from paper-based forms. Specifically, this study reveals that users commit fewer errors and prefer simple forms limited to a single concept per screen. This conclusion significantly alters the recommendations for designing business forms.

Formal Verification Of Urban Traffic System Using The Concept Of Fuzzy Workflow Simulation, Manuj Darbari, Abhay Kumar Srivastava, Sanjay Medhavi

Journal of International Technology and Information Management

Modeling complex urban traffic system requires extensive use of workflow methodologies which can simulate almost real time traffic situations. Number of studies were done in the field of Urban Traffic Simulation like PLOTS, NETSIM and PALAMICS but none of them could provide a real formal solution. Our paper proposes a methodology using Fuzzy Petri nets for modeling real time traffic system. Fuzzy Petrinets are also visualised and tested by using Flow- Charter and HPSIM software packages. These packages help in providing successive iterations of process model for further refinement.

Supporting The Virtual Community: Social Bookmarking As A User- Based Classification Scheme In A Knowledge Library, Nicole Lytle, Tony Coulsom

Journal of International Technology and Information Management

Knowledge libraries hold the promise of widespread access to information available anywhere, anytime, freeing patrons from the geographical and temporal boundaries that currently exist. The classification of materials and subsequent searching of knowledge library content is an overall problem with many complex parts. Relevant classification is important for optimal information retrieval. This is especially important for the virtual communities that exist with extended organizations. Rooted in the virtual community and digital library literature, this paper develops a theory for improving the information classification and retrieval process of knowledge libraries that support virtual communities by applying social bookmarking techniques.

Rapid Development Of Multimedia Instructional Modules For Information Technology Education, Nanda Ganesan

Journal of International Technology and Information Management

A multifaceted learning model was developed for implementing e-learning in a largely commuter campus. The primary objective of the model was to build a flexible learning environment that combined the learning effectiveness of in-class learning with the flexibility and accessibility of online learning. One of the components of the model was the multimedia instructional modules produced to teach various Information Technology courses. Several different types of modules were produced representing chalk-and-talk type of lectures, PowerPoint presentations and software tutorials. The chalk-and-talk type of lecture modules and the software tutorials that emulated the in-class learning experience contributed positively towards enhancing the …

Can Information Systems Foster Emotional Intelligence? A Design Theory-Based Approach, Richard J. Burkhard, Thomas A. Horan, Brian N. Hilton, Michael Leih

Journal of International Technology and Information Management

Researchers in Information Systems (IS) have conducted extensive research into various kinds of collaboration systems over the last twenty-five years. A parallel stream of inquiry in psychology and management has developed research in organizational Emotional Intelligence, which contributes to the effectiveness of group interactions by increasing cooperation and reducing conflict. Collaboration systems present a special opportunity to introduce soft management functions such as Emotional Intelligence because they are designed as an intelligent channel of interaction between group members. This research used an Information Systems Design Theory approach to guide the integration of Emotional Intelligence functions into collaboration systems. Two artifact …

Business Risks: When Is Fails To Detect Circumvention Activities, Stanley X. Lewis Jr., J. Scott Magruder, Eddy J. Burks, Carl Smolinski

Journal of International Technology and Information Management

A business must recognize and address various risk factors when establishing and maintaining its information system. The overall risk to management is that the control environment does not protect proprietary business data and the financial reporting system that produces financial statements and other information used by investors, creditors and regulatory agencies. These risks require that management implement efforts to ensure the integrity and effectiveness of control procedures over business activities while being aware of additional system issues such as failing to adequately consider other risks which are more business-oriented including the risk of failing to prevent or detect fraudulent or …

Bess: BIofuel ENergy SYstems SImulator: Life Cycle Energy & Emissions Analysis Model For Corn-Ethanol Biofuel Production Systems -- User’S Guide For The Bess Model, Adam Liska, Haishun Yang, Daniel T. Walters, Kenneth Cassman, Terry Klopfenstein, Galen Erickson, Virgil R. Bremer, Richard K. Koelsch, Dan Kenney, Patrick Tracy

Adam Liska Papers

The BESS model is a software tool to calculate the energy efficiency, greenhouse gas (GHG) emissions, and natural resource requirements of corn–to-ethanol biofuel production systems. The model provides a “cradle-to-grave” analysis of the production life cycle of biofuels from the creation of material inputs to finished products, producing an inventory of distributed GHG emissions from fossil fuels and a few key indirect emissions in the production life cycle. The model parameters can be set by the user to achieve the highest accuracy in evaluating a single corn-ethanol biorefinery and its surrounding feedstock crop production zone. The model equations and summary …

Optical, Structural, And Magnetic Properties Of Cobalt Nanostructure Thin Films, D. Schmidt, A. C. Kjerstad, Tino Hofmann, Ralph Skomski, Eva Schubert, Mathias Schubert

Nebraska Center for Materials and Nanoscience: Faculty Publications

We report on optical, structural, and magnetic properties of two substantially different cobalt nanostructure thin films deposited at an oblique angle of incidence of 85° away from the substrate normal. Comparison is made between an achiral columnar thin film grown without substrate rotation and a chiral nanocoil sculptured thin film by glancing angle deposition with substrate rotation. Generalized spectroscopic ellipsometry is employed to determine geometrical structure properties and the anisotropic optical constants of the films in the spectral range from 400 to 1000 nm. The magnetic properties are analyzed with a superconducting quantum interference device magnetometer. Both nanostructure thin films …

Experimental Investigation Of A Novel Blast Wave Mitigation Device, Zhenbi Su, Wen Peng, Zhaoyan Zhang, George Gogos, Reed Skaggs, Bryan Cheeseman, Chian Fong Yen

Department of Mechanical and Materials Engineering: Faculty Publications

A novel blast wave mitigation device was investigated experimentally in this paper. The device consists of a pistoncylinder assembly. A shock wave is induced within the cylinder when a blast wave impacts on the piston. The shock wave propagates inside the device and is reflected repeatedly. The shock wave propagation process inside the device lengthens the duration of the force on the base of the device to several orders of magnitude of the duration of the blast wave, while it decreases the maximum pressure over an order of magnitude. Two types of experiments were carried out to study the blast …

Inhomogeneous Degradation Of Polymer Electrolyte Membrane In Pem Fuel Cells, Xinyu Huang, Wonseok Yoon

Faculty Publications

Membrane durability is one of the technical barriers for the commercialization of polymer electrolyte membrane (PEM) fuel cells. Membrane embrittlement (a form of mechanical weakening) can lead to the frequently observed “sudden death” behavior of PEM fuel cells. It is the objective of this study to explore the fundamental mechanisms of the mechanical weakening of perfluorosulfonic acid (PFSA) based electrolyte membranes during the accelerated degradation test.

Sulfur Dioxide Crossover During The Production Of Hydrogen And Sulfuric Acid In A Pem Electrolyzer, John A. Staser, John W. Weidner

Faculty Publications

A proton exchange membrane (PEM) electrolyzer has been investigated as a viable system for the electrolysis step in the thermochemical conversion of sulfur dioxide to sulfuric acid for the large-scale production of hydrogen. Unfortunately, during operation, sulfur dioxide can diffuse from the anode to the cathode. This has several negative effects, including reduction to sulfur that could potentially damage the electrode, consumption of current that would otherwise be used for the production of hydrogen, introduction of oxygen and SO₂ to the hydrogen stream, and loss of sulfur to the cycle. However, proper water management can reduce or eliminate the …

The Effect Of Copt Crystallinity And Grain Texturing On Properties Of Exchange-Coupled Fe/Copt Systems, H. Oguchi, A. Zambano, M. Yu, Jason R. Hattrick-Simpers, D. Banerjee, Y. Liu, Z. L. Wang, J. P. Liu, S. E. Lofland, D. Josell, I. Takeuchi

Faculty Publications

The effect of the crystallinity and the grain texturing of CoPt hard layers on exchange coupled Fe/CoPt soft/hard magnetic systems was studied using gradient thickness multilayer thin films. We have studied the hard layer structures by transmission electron microscopy and x-ray diffraction, and characterized the exchange coupling interaction through magnetization loops obtained by the magneto-optical Kerr effect measurement. We found that exchange coupling strongly depends on the crystalline characteristics of the CoPt hard layer. There is correlation between the mixture of different grain orientations of the CoPt hard layer and coupling efficiency. In particular, interlayer coupling is enhanced when there …

Polymer Composite And Nanocomposite Dielectric Materials For Pulse Power Energy Storage, P. Barber, S. Balasubramanian, Y. Anguchamy, S. Gong, A. Wibowo, H. Gao, Harry J. Ploehn, Hans-Conrad Zur Loye

Faculty Publications

This review summarizes the current state of polymer composites used as dielectric materials for energy storage. The particular focus is on materials: polymers serving as the matrix, inorganic fillers used to increase the effective dielectric constant, and various recent investigations of functionalization of metal oxide fillers to improve compatibility with polymers. We review the recent literature focused on the dielectric characterization of composites, specifically the measurement of dielectric permittivity and breakdown field strength. Special attention is given to the analysis of the energy density of polymer composite materials and how the functionalization of the inorganic filler affects the energy density …

Mathematical Modeling Of Growth Of Salmonella In Raw Ground Beef Under Isothermal Conditions From 10 To 45° C, Vijay K. Juneja, Martin Valenzuela Melendres, Lihan Huang, Jeyamkondan Subbiah, Harshavardhan Thippareddi

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The objective of this study was to develop primary and secondary models to describe the growth of Salmonella in raw ground beef. Primary and secondary models can be integrated into a dynamic model that can predict the microbial growth under varying environmental conditions. Growth data of Salmonella at nine different isothermal conditions — 10,15, 20, 25, 28, 32, 35, 42, and 45 °C were first fitted into primary models, namely the logistic, modified Gompertz, Baranyi, and Huang models. Performances of these models were evaluated by using various statistical criteria, namely mean square error (MSE), pseudo-R², −2 log likelihood, …

Effect Of Timing Of A Deficit-Irrigation Allocation On Corn Evapotranspiration, Yield, Water Use Efficiency And Dry Mass, J. O. Payero, David D. Tarkalson, Suat Irmak, Don Davison, James L. Petersen

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Water regulations have decreased irrigation water supplies in Nebraska and some other areas of the USA Great Plains. When available water is not enough to meet crop water requirements during the entire growing cycle, it becomes critical to know the proper irrigation timing that would maximize yields and profits. This study evaluated the effect of timing of a deficit-irrigation allocation (150 mm) on crop evapotranspiration (ETc), yield, water use efficiency (WUE = yield/ETc), irrigation water use efficiency (IWUE = yield/irrigation), and dry mass (DM) of corn (Zea mays L.) irrigated with subsurface drip irrigation in the semiarid climate of …

Special Issue On Evapotranspiration Measurement And Modeling, Samuel Ortega-Farias, Suat Irmak, R. H. Cuenca

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Water availability for irrigation throughout the world has been reduced in recent years due to a combination of frequent droughts and competition for water resources among agricultural, industrial, and urban users. In addition, some major agricultural areas face moderate to significant reductions of rainfall, or changes in timing of stream flow due to changes in timing of snowmelt, as a result of global climate change. Under such conditions, sophisticated irrigation water management will be required to optimize water use efficiency and maintain sufficient levels of crop productivity and quality. A key factor to achieve these targets is the estimation of …

Regional Co2 And Latent Heat Surface Fluxes In The Southern Great Plains: Measurements, Modeling, And Scaling, W. J. Riley, Sebastien C. Biraud, Margaret S. Torn, Marc L. Fischer, David P. Billesbach, Joe A. Berry

Department of Agricultural and Biological Systems Engineering: Faculty Publications

[1] Characterizing net ecosystem exchanges (NEE) of CO2 and sensible and latent heat fluxes in heterogeneous landscapes is difficult, yet critical given expected changes in climate and land use. We report here a measurement and modeling study designed to improve our understanding of surface to atmosphere gas exchanges under very heterogeneous land cover in the mostly agricultural U.S. Southern Great Plains (SGP). We combined three years of site-level, eddy covariance measurements in several of the dominant land cover types with regional-scale climate data from the distributed Mesonet stations and Next Generation Weather Radar precipitation measurements to calibrate a land surface …

A Sequential Bayesian Approach For Hydrologic Model Selection And Prediction, Kuo-Lin Hsu, Hamid Moradkhani, Soroosh Sorooshian

Civil and Environmental Engineering Faculty Publications and Presentations

When a single model is used for hydrologic prediction, it must be capable of estimating system behavior accurately at all times. Multiple-model approaches integrate several model behaviors and, when effective, they can provide better estimates than that of any single model alone. This paper discusses a sequential model fusion strategy that uses the Bayes rule. This approach calculates each model's transient posterior distribution at each time when a new observation is available and merges all model estimates on the basis of each model's posterior probability. This paper demonstrates the feasibility of this approach through case studies that fuse three hydrologic …

Feedback Between Residual Circulations And Sediment Distribution In Highly Turbid Estuaries: An Analytical Model, Stefan A. Talke, Huib E. De Swart, H. M. Schuttelaars

Civil and Environmental Engineering Faculty Publications and Presentations

Motivated by field studies of the Ems estuary which show longitudinal gradients in bottom sediment concentration as high as O(0.01 kg/m⁴), we develop an analytical model for estuarine residual circulation based on currents from salinity gradients, turbidity gradients, and freshwater discharge. Salinity is assumed to be vertically well mixed, while the vertical concentration profile is assumed to result from a balance between a constant settling velocity and turbulent diffusive flux. Width and depth of the model estuary are held constant. Model results show that turbidity gradients enhance tidally averaged circulation upstream of the estuarine turbidity maximum (ETM), …

An Idealized Model And Systematic Process Study Of Oxygen Depletion In Highly Turbid Estuaries, Stefan A. Talke, Huib E. De Swart, Victor De Jonge

Civil and Environmental Engineering Faculty Publications and Presentations

The sensitivity of oxygen depletion in turbid estuaries to parameters like freshwater discharge, depth, and sediment availability is investigated using an idealized model. The model describes tidally averaged circulation and suspended sediment concentration (SSC), which are input into an advection–diffusion sink module of dissolved oxygen (DO). Based on the analysis of field data collected in the Ems estuary, the modeled oxygen depletion rates are proportional to SSC. The model is calibrated to the observed variation of DO with SSC and temperature. Modeled DO closely tracks changes to the estuarine turbidity zone (ETZ): increased channel depth, decreased freshwater discharge, and decreased …

The Potential Contribution Of Organic Salts To New Particle Growth, Kelley Barsanti, Peter H. Mcmurry, J. N. Smith

Civil and Environmental Engineering Faculty Publications and Presentations

Field and lab measurements suggest that low-molecular weight (MW) organic acids and bases exist in accumulation and nucleation mode particles, despite their relatively high pure-liquid vapor pressures. The mechanism(s) by which such compounds contribute to the mass growth of existing aerosol particles and newly formed particles has not been thoroughly explored. One mechanism by which low- MW compounds may contribute to new particle growth is through the formation of organic salts. In this paper we use thermodynamic modeling to explore the potential for organic salt formation by atmospherically relevant organic acids and bases for two system types: one in which …

Bacterial Characterization Of Louisiana Groundwater Contaminated By Dnapl-Containing Chloroethanes And Other Solvents, Kimberly Bowman

LSU Doctoral Dissertations

In support of an effort to determine the feasibility of using an in-situ bioremediation strategy for cleanup of groundwater in an area containing chlorinated solvents present as a dense non-aqueous phase liquid (DNAPL), the bacterial population in the groundwater at a Superfund site located near Baton Rouge, Louisiana was characterized. More than 3¡Á107 cells/mL in the groundwater were observed via microscopy. Universal bacterial and ¡°Dehalococcoides¡±-specific 16S rRNA gene libraries were constructed and analyzed. Universal clones grouped into 18 operational taxonomic units (OTUs), as defined by sequence similarity ¡Ý97.0%, which included several as yet undescribed organisms. Multiple unique sequences closely related …

Super Resolution And Dynamic Range Enhancement Of Image Sequences, Lutfi Murat Gevrekci

LSU Doctoral Dissertations

Camera producers try to increase the spatial resolution of a camera by reducing size of sites on sensor array. However, shot noise causes the signal to noise ratio drop as sensor sites get smaller. This fact motivates resolution enhancement to be performed through software. Super resolution (SR) image reconstruction aims to combine degraded images of a scene in order to form an image which has higher resolution than all observations. There is a demand for high resolution images in biomedical imaging, surveillance, aerial/satellite imaging and high-definition TV (HDTV) technology. Although extensive research has been conducted in SR, attention has not …

Parametric Study Of Efficiency Measures For Home Energy Conservation In Las Vegas, Nevada, Todd M. France

UNLV Theses, Dissertations, Professional Papers, and Capstones

Pulte Homes, a production home builder and community developer partnering with the U.S. Department of Energy's Building America program, has collaborated with the Center for Energy Research at the University of Nevada, Las Vegas and NV Energy, the local electric utility, on an energy conservation project in the Las Vegas Valley.

This study entails four model homes at a new development in the Summerlin community of Las Vegas, Nevada, named Villa Trieste. The home models, ranging in floor plan area from 1,487 to 1,777 square feet, have been constructed under the Environments for Living program and are LEED (Leadership in …

Criticality Studies Of Actinides Within Fissures, Trevor Wilcox

UNLV Theses, Dissertations, Professional Papers, and Capstones

The storage of nuclear waste in underground storage facilities presents numerous engineering challenges and risks. Experimental verification of engineered underground storage is impractical or prohibitively expensive, leaving scientists with few options. A 1995 report by Bowman and Venneri of the Los Alamos National Laboratory generated considerable controversy by hypothesizing that wastes composed of fissionable plutonium leached from underground storage containers could pose a nuclear criticality hazard. They proposed cases where plutonium collected in underground fractures could lead to sustained nuclear fission. In overmoderated cases, they argued that the resulting release of energy from fission could result in steam explosions, or …

Optimization Of Solid Oxide Fuel Cell Interconnect Design, Krishna C. Pulagam

UNLV Theses, Dissertations, Professional Papers, and Capstones

Performance of solid oxide fuel cells (SOFC) is dependent of a set of complex physical and chemical processes occurring simultaneously. Interconnect for SOFC is important as it provides electrical connection between anode of one individual cell to the cathode of neighboring one. It also acts as a physical barrier to protect the air electrode material from the reducing environment of the fuel on the fuel electrode side, and it equally prevents the fuel electrode material from contacting with oxidizing atmosphere of the oxidant electrode side. A three-dimensional numerical model has been developed to evaluate the SOFC including the current collector, …

Analysis And Design Of Low Power Cmos Ultra Wideband Receiver, Abdul Bhuiyan

UNLV Theses, Dissertations, Professional Papers, and Capstones

This research concentrates on the design and analysis of low power ultra wideband receivers for Multiband Orthogonal Frequency Division Multiplexing systems. Low power design entails different performance tradeoffs, which are analyzed. Relationship among power consumption, achievable noise figure and linearity performance including distortion products (cross-modulation, inter-modulation and harmonic distortion) are derived. From these relationships, circuit design proceeds with allocation of gain among different sub circuit blocks for power optimum system.

A power optimum RF receiver front-end for MB-OFDM based UWB systems is designed that covers all the MB-OFDM spectrum between 3.1 GHZ to 9.6 GHZ. The receiver consists of a …