Digital Commons Network^™

Mitigation Of Impact Vibrations Using Impedance Mismatch In Cylindrical Structures, Sachiko Sueki

UNLV Theses, Dissertations, Professional Papers, and Capstones

The focus of this work is to study the phenomenon of material impedance mismatch to determine its effect on the mitigation of high frequency accelerations in projectile and long bar structures within linear ranges of materials. In this study, the acceleration responses of structures with various materials and material combinations were studied experimentally, numerically and by the Finite Element Analysis (FEA). Air-gun tests conducted by the US Army Research Laboratory were modeled using FEA to simulate the acceleration pulse and shock waves experienced by artillery components during a launch. After the prototype of projectile was selected, further studies were conducted …

Parametric Study Of Stimulus-Response Behavior Incorporating Vehicle Heterogeneity In Car-Following Models, Saidi Siuhi

UNLV Theses, Dissertations, Professional Papers, and Capstones

The objective of this study was to develop a family of car-following models that address the shortcomings of car-following models developed by General Motors (GM) in the 1950s. The developed models consist of separate models for acceleration, deceleration, and steady-state responses for congested freeway traffic conditions. The study calibrated the models using individual vehicle trajectory data collected on a segment of Interstate 101 in Los Angeles, California. Furthermore, the study validated the models using individual vehicle trajectory data collected on a segment of Interstate 80 in Emeryville, California. The study used nonlinear regression with robust standard errors to estimate the …

Communication Technologies: Diffusion Of Online News Use And Credibility Among Young Web Users In The Information Age, Chee Youn Kang

UNLV Theses, Dissertations, Professional Papers, and Capstones

The increasing popularity and extensive usage of communication technologies, particularly the Internet and online news, makes it important to obtain an insightful perception of the new media. The purpose of this study is to examine the diffusion of online news use and credibility among young web users in terms of how these main users adopt, use, and trust the new media. This study attempts to find which online news sites are widely used by this group, based on the credibility of online news adopted among undergraduate and graduate students at the University of Nevada, Las Vegas (UNLV), in which demographic …

Predisposition Factors Of Career And Technical Education Transfer Students: A Hermeneutic Phenomenology Study, Warren Glen Hioki

UNLV Theses, Dissertations, Professional Papers, and Capstones

Various econometric, sociological, and combined research models (e.g., Hossler and Gallagher's preeminent Three-Phase Model on College Choice) provide help in understanding high school students in their decision-making stages and college experience. Many studies that utilize these models on college choice strongly substantiate and perpetuate the long-standing dichotomy between students who aspire to attend college in pursuit of upward mobility through the traditional baccalaureate pathway versus a community college Career and Technical Education (CTE) pathway. High school students' aspirations to attend a 4-year institution, and more recently, the community college, are a focal point.

A review of the literature as it …

Disease In The Desert: Las Vegas As A Case Study Of How First Responders And Emergency Managers Understand Novel Threats To Human Health And Plan To Respond During Biological Emergencies, Monique Williamson

UNLV Theses, Dissertations, Professional Papers, and Capstones

Over recent years it has become clear that technological advancements, globalization, and ecological change, combined with the onset of increased terrorist incidents, are all currently working to create an extremely hazardous environment in terms of pathogenic invasion. Realizing that infectious diseases are both newly emerging and re-emerging in many parts of the world, the question of how prepared an expansive United States will be in the face of an oncoming global pandemic is easily raised. Using Las Vegas as an example of just how unequipped a largely visited U.S. city may be in the face of such a situation, this …

Analysis Of A Caliche Stiffened Pile Foundation, Richard C. Stone Jr.

UNLV Theses, Dissertations, Professional Papers, and Capstones

Cemented carbonate deposits (known locally as "caliche") in Las Vegas have been used to support shallow and deep foundations with relatively high bearing pressures compared to soil. Most high rise structures in Las Vegas are founded on either a large mat or a long pile foundation. Recently, a new foundation type consisting of a short pile system bonded to shallow cemented layers was utilized for a large high rise building in Las Vegas and settlements during construction were recorded. The bonding of caliche layers together with short piles forms a caliche stiffened pile (CSP) foundation. The CSP foundation is unique …

Passage And Initial Implementation Of The Supplemental Educational Services Element Of The No Child Left Behind Act: An Historical Inquiry Study, Brad D. Christensen

UNLV Theses, Dissertations, Professional Papers, and Capstones

With reports alleging a sharp decline in student achievement in the last several years, there has been a call for higher standards in the United States education system. In response, with bipartisan support, politicians overwhelmingly passed the No Child Left Behind (NCLB) Act of 2001. NCLB, the most recent reauthorization of the Elementary and Secondary Education Act (ESEA), mandated increasing the educational performance of all children by focusing on accountability for student achievement, flexibility, higher academic standards, research-based reforms, parental choice, annual testing to measure student progress, analysis of the annual testing data, and sanctions for schools where students did …

Effect Of Mechanical Vibrations On Light Emitting Diode Luminaires, Jayalakshmi Paladugu

UNLV Theses, Dissertations, Professional Papers, and Capstones

In this work, a LED and two types of Compact fluorescent lamps were investigated for the intensity variation due to mechanical vibrations in the range of 0 to 30 HZ. In general, subjecting the lamps to 24-hour vibration affects the total intensity percentage variations of peak intensities after vibrations is in the range of -25 to +15% compared to those of no vibrations for the light emitting diode luminaires. For the case of compact fluorescent lamps (Nuvue) the variations are in range from +10 to +35%, whereas for the Compact fluorescent lamps (Ecosmart) the intensity peaks range from -10 to …

Islanded Operation Of A Distribution Feeder With Distributed Generation, Chandu Venu

UNLV Theses, Dissertations, Professional Papers, and Capstones

A distribution system that is equipped with distributed generators, such as roof-mounted photovoltaic systems, can operate as a microgrid (i.e., separated from the grid) under some specific conditions. A key feature of a microgrid is its ability to separate and isolate itself from the utility seamlessly with little or no disruption to the loads within the microgrid. Then, when the utility grid returns to normal, the microgrid automatically resynchronizes and reconnects itself to the grid, in an equally seamless manner. This thesis addresses the conditions necessary for proper microgrid operation: these include local generation-load mismatch, local energy storage, load switching, …

Studying The Impacts Of Primary Incidents On Freeways To Identify Secondary Incidents, Rohit Reddy Saddi

UNLV Theses, Dissertations, Professional Papers, and Capstones

Freeway incidents are associated with different impacts such as traffic congestion, delays, fuel consumption, secondary incidents etc. Secondary incidents are caused due to primary incidents and require the same personnel who are already engaged. This thesis studies various impacts caused by primary incident in space and time occurring on the freeways and these results are applied to identify secondary incidents. Three types of impacts are identified and proposed in this study. Dynamic nature of queue length in the direction of accident is studied. Dynamic nature of congestion in the opposite direction of the freeway till the accident is cleared is …

Effects Of Explicit Subtraction Instruction On Fifth Grade Students With Learning Disabilities, Danielle Ferreira

UNLV Theses, Dissertations, Professional Papers, and Capstones

This study involved an investigation of the effects of strategy instruction integrated with the concrete-representational-abstract teaching sequence on students with learning disabilities. A multiple probe design across subjects with one replication was used in this study. Two sets of data were analyzed to determine effectiveness of the independent variable (intervention lessons). The first data set consisted of pre and posttest percentage scores and the second data set consisted of baseline, intervention, and maintenance probe scores that were collected throughout the study per the parameters of a multiple probe design. The probe scores were plotted in line graph format and analyzed …

On-Board Three-Dimensional Object Tracking: Software And Hardware Solutions, Ajay Kumar Mandava

UNLV Theses, Dissertations, Professional Papers, and Capstones

We describe a real time system for recognition and tracking 3D objects such as UAVs, airplanes, fighters with the optical sensor. Given a 2D image, the system has to perform background subtraction, recognize relative rotation, scale and translation of the object to sustain a prescribed topology of the fleet. In the thesis a comparative study of different algorithms and performance evaluation is carried out based on time and accuracy constraints. For background subtraction task we evaluate frame differencing, approximate median filter, mixture of Gaussians and propose classification based on neural network methods. For object detection we analyze the performance of …

Extents And Limits Of Radioscopic Detection Of Nuclear Materials In Cargo Containers With Two Megavoltage Energy Barriers, Vijay Kumar Mandava

UNLV Theses, Dissertations, Professional Papers, and Capstones

The megavoltage X-ray technology is utilized for detecting nuclear materials in cargo containers. Interlaced response is obtained by switching rapidly between 6MeV and 9 MeV beams. It is known that the ratio of penetration levels of cargo contents taken at nominal and dual energies provides the information about atomic numbers of materials, and thus can also indicate the threat group. However, the identification is not straightforward if combinations of materials are present. The latter can lead to misdetections. It is imperative to know what are the extent and the limit of the currently employed technology, and how to carry out …

Design And Characterization Of A Shock And Vibration Mitigation Seat System, George Samaan Ladkany

UNLV Theses, Dissertations, Professional Papers, and Capstones

Extensive research has been conducted into the development of pneumatic seatbladder systems for shock and vibration mitigation for use in current U.S military vehicle envelopes. This research expands on the previous work through an elaborate experimental characterization of four prototype air bladder seat cushion systems. The experimental characterization conducted included shock testing, continuous vibration, and internal dynamic pressure measured during the shock event.

The shock testing was conducted both at the Army Research Lab as well at UNLV. The shock testing conducted at UNLV was performed on a drop tower designed and constructed during the time of this research. The …

Empirically Derived Formulas To Predict Indoor Maximum, Average, And Minimum Temperatures In Roofpond Buildings Using Minimum Climatic Information, Ibrahim Kivarkis Kako

UNLV Theses, Dissertations, Professional Papers, and Capstones

This thesis introduces an empirically developed formula to predict the comfort conditions and thermal performance of a Skytherm(TM) Southwest Roofpond placed over a light-weight un-insulated structure built at the School of Architecture at the University of Nevada, Las Vegas.

The predictive formula introduced in this study may be used in different parts of the world (particularly developing nations where insulation and air-conditioning are rarely used) to predict the performance of a Skytherm(TM) Southwest Roofpond using minimal climate data.

The data collected in the experimental setup at the Natural Energies Advanced Technologies Laboratory included outside and inside temperatures of various surfaces …

Quantity-Based Cost Forecasting System For Street Construction Projects, Nipesh Pradhananga

UNLV Theses, Dissertations, Professional Papers, and Capstones

Construction projects typically are not withdrawn after going into the competitive bidding process. The decision of contracting authorities regarding which projects will proceed to the bidding stage depends, in part, upon the early estimates of probable cost. Efforts are made to make this estimate as realistic as possible. Irrespective of the estimate of probable cost, the actual project cost is established by the amount of the winning bid.

This study analyzed historical bid data of street construction projects undertaken by the Public Works Department, Clark County, Nevada, from 1991 through 2006. The focus of this study was on utilizing statistical …

Optimal Design Of Discrete-Time Delta Sigma Modulators, Matthew Edward Jackson

UNLV Theses, Dissertations, Professional Papers, and Capstones

In this thesis, optimal signal transfer functions (STFs) and noise transfer functions (NTFs) for discrete time delta sigma (ΔΣ) modulators are determined. For a given oversampling rate (OSR), these STFs and NTFs are optimized with respect to a weighted combination of the ΔΣ modulator's signal-to-noise ratio (SNR) and dynamic range (DR). This optimization problem is solved using a novel hybrid orthogonal genetic (HOG) algorithm that uses customized genetic operators to improve algorithm performance and accuracy when applied to multimodal, non-differentiable performance surfaces. To generate optimal system functions, the HOG algorithm is implemented as a constrained global optimizer to minimize cost …

Experimental And Natural Variation In Hovering Flight Capacity In Bees, Hymenoptera: Apidae, Jason Thomas Vance

UNLV Theses, Dissertations, Professional Papers, and Capstones

In honey bees, the capacity for flight underlies many behaviors which impact fitness and longevity, such as the ability to forage or evade predators. However, flight capacity is not fixed across bees' lifespan, which is punctuated by a suite of physiological changes that accompany age and the transition from in-hive to foraging behaviors; thus, flight capacity may vary during periods of development, senescence, or in response to morphological damage such as wing wear. This dissertation describes the biomechanics and aerodynamics which contribute to the scope of honey bee flight performance, and investigates how age, behavioral development, and wing-wear affects flight …

Response Of Sandhill Crane (Grus Canadensis Riverine Roosting Habitat To Changes In Stage And Sandbar Morphology, Paul Kinzel, Jonathan Nelson, Ashley Heckman

United States Geological Survey: Staff Publications

Over the past century, flow regulation and vegetation encroachment have reduced active channel widths along the central Platte River, Nebraska. During the last two decades, an annual program of in-channel vegetation management has been implemented to stabilize or expand active channel widths. Vegetation management practices are intended to enhance riverine habitats which include nocturnal roosting habitat for sandhill cranes. Evaluating the success of other management treatments such as streamflow modification requires an understanding of how flow shapes the sandbars in the river and how sandbar morphology interacts with flow to create crane habitat. These linkages were investigated along a 1-km …

"Daughters Of British Blood" Or "Hordes Of Men Of Alien Race" The Homesteads-For-Women Campaign In Western Canada, Sarah Carter

Great Plains Quarterly (through 2013)

In May 1910 Mildred Williams, a young teacher in Saskatoon, Saskatchewan, made headlines across Western Canada for her pluck and stamina as she waited for twelve days and nights on a chair on the stairs outside the door of the land office in Saskatoon to claim a homestead (see Fig. 1). She was determined to file on a half-section (320 acres) of valuable land near Kindersley. Williams put up with a great deal of inconvenience during her days and nights on the stairs. On the second day she was challenged by a man who wanted the same property and who …

Updating The 2001 National Land Cover Database Land Cover Classification To 2006 By Using Landsat Imagery Change Detection Methods, George Xian, Collin Homer, Joyce Fry

United States Geological Survey: Staff Publications

The recent release of the U.S. Geological Survey (USGS) National Land Cover Database (NLCD) 2001, which represents the nation's land cover status based on a nominal date of 2001, is widely used as a baseline for national land cover conditions. To enable the updating of this land cover information in a consistent and continuous manner, a prototype method was developed to update land cover by an individual Landsat path and row. This method updates NLCD 2001 to a nominal date of 2006 by using both Landsat imagery and data from NLCD 2001 as the baseline. Pairs of Landsat scenes in …

Self-Assembly Of Magnetic Ni Nanoparticles Into 1d Arrays With Antiferromagnetic Order, Valery Bliznyuk, Srikanth Singamaneni, Sarbeswar Sahoo, Srinivas Polisetty, Xi He, Christian Binek

Christian Binek Publications

In this paper, we report on the magnetic properties of isolated nanoparticles and interacting nanochains formed by the self-assembly of Ni nanoparticles. The magnetic properties were studied using superconducting quantum interference device (SQUID) magnetometry and magnetic force microscopy (MFM). We demonstrate that single-domain Ni nanoparticles spontaneously form one-dimensional (1D) chains under the influence of an external magnetic field. Furthermore, such magnetic field-driven self-assembly in conjunction with surface templating produces regular arrays of 1D nanochains with antiferromagnetic intra-chain order. The antiferromagnetic order, which is in striking contrast to what is found for non-interacting nanoparticle assemblies within the chains, can be evidenced …

A Disability By Any Other Name Is Still A Disability: Log Cabin, The Disability Spectrum, And The Ada (Aa), Gabrielle L. Goodwin

Articles by Maurer Faculty

In EEOC v. Lee's Log Cabin, the Seventh Circuit followed the Supreme Court precedent of the last decade that has increasingly narrowed the determination of what constitutes a disabled individual under the Americans with Disabilities Act. In 2008, Congress passed the ADA Amendments Act in an attempt to restore the ADA to its original purpose and the original vision of the ADA's drafters and supporters. Whether these amendments will produce dramatic changes in the way the administrative agencies and courts apply the ADA remains to be seen. Nonetheless, the only way the ADA or its amendments will successfully protect against …

Capturing And Handling Wild Animals, Sanford D. Schemnitz, Gordon R. Batcheller, Matthew J. Lovallo, H. Bryant White, Michael W. Fall

United States Department of Agriculture Wildlife Services: Staff Publications

The art of capturing wild animals for food and clothing is as old as human existence on earth. However, in today’s world, reasons for catching wild species are more diverse. Millions of wild animals are captured each year as part of damage and disease control programs, population regulation activities, wildlife management efforts, and research studies. Many aspects of animal capture, especially those associated with protected wildlife species, are highly regulated by both state and federal governmental agencies. Animal welfare concerns are important regardless of the reason for capture. In addition, efficiency (the rate at which a device or system catches …

Feasibility Of Infectious Prion Digestion Using Mild Conditions And Commercial Subtilisin, John L. Pilon, Paul B. Nash, Terry Arver, Don Hoglund, Kurt C. Vercauteren

United States Department of Agriculture Wildlife Services: Staff Publications

Two serine protease enzymes, subtilisin 309 and subtilisin 309-v,were used to digest brain homogenates containing high levels of prion infectivity using mildly alkaline conditions to investigate prion decontamination methods. To establish that PrP^res infectivity was eliminated, we utilized the Rocky Mountain Laboratory (RML) mouse-adapted scrapie model system for bioassay. Only one digestion condition (subtilisin 309 at 138mAU/ml, 55^◦C and 14 h digestion time pH 7.9) was considered to be highly relevant statistically (P < 0.001) compared to control, with 52% of challenged mice surviving until the end of the study period. In contrast, treatment of PrP^res by autoclaving at 134^◦C or treatment with hypochlorite at a concentration of 20,000ppm completely protected mice from prionosis. Further, in …

Radiation-Induced Decomposition Of The Metal-Organic Molecule Bis(4-Cyano-2,2,6,6-Tetramethyl-3,5-Heptanedionato)Copper(Ii), David Wisbey, Ning Wu, Yaroslav B. Losovyj, Ihor Ketsman, A. N. Caruso, Danqin Feng, John Belot, Elio Vescovo, Peter A. Dowben

Peter Dowben Publications

The effects of vacuum ultraviolet radiation on the adsorbed copper center molecule bis(4-cyano-2,2,6,6- tetramethyl-3,5-heptanedionato)copper(II) (or Cu(CNdpm)₂), (C₂₄H₃₆N₂O₄Cu, Cu(II)) was studied by photoemission spectroscopy. Changes in the ultraviolet photoemission spectra (UPS) of Cu(CNdpm)₂, adsorbed on Co(1 1 1), indicate that the ultraviolet radiation leads to decomposition of Cu(CNdpm)₂ and this decomposition is initially dominated by loss of peripheral hydrogen.

Induced Spin Polarization Of Copper Spin 1/2 Molecular Layers, David Wisbey, Ning Wu, Danqin Feng, A. N. Caruso, J. Belot, Yaroslav B. Losovyj, Elio Vescovo, Peter A. Dowben

Peter Dowben Publications

Thin films of the metal organic molecule bis(4-cyano-2,2,6,6-tetramethyl-3,5-heptanedionato)copper(II) (or Cu(CNdpm)₂), (C₂₄H₃₆N₂O₄Cu, Cu(II)), deposited on ferromagnetic Co(111) at 40 K, exhibit a finite electron spin polarization. The spin polarization magnitude and sign for Cu(CNdpm)₂ deposited on Co(111) is coverage dependent, but deviates from the mean field expectations for a simple paramagnet on a ferromagnetic substrate. The spin asymmetry is seen to favor select molecular orbitals, consistent with the predicted single molecule density of states. The overlayer polarization observed indicates a strong influence of the ferromagnetic Co(111) substrate and some extra-molecular …

Avian Visual System Configuration And Behavioural Response To Object Approach, Bradley F. Blackwell, Esteban Fernandez-Juricic, Thomas W. Seamans, Tracy Dolan

United States Department of Agriculture Wildlife Services: Staff Publications

Antipredator behaviour theory provides a framework to understand the mechanisms behind human– wildlife interactions; however, little is known about the role of visual systems in the responses to humans. We quantified responses of brown-headed cowbirds, Molothrus ater (Boddaert), and mourning doves, Zenaida macroura (Linnaeus), to object approach (a ground-based vehicle) and vehicle lighting regimen, and we examined two visual properties (visual acuity and visual fields) that could influence antipredator behaviour. Brown-headed cowbird groups exposed to vehicle approach and constant illumination of the vehicle-mounted lamp showed alert behaviour earlier than did groups exposed to pulsating treatments or no lamp. Interestingly, light …

Regional Assessment On Influence Of Landscape Configuration And Connectivity On Range Size Of White-Tailed Deer, W. David Walter, Kurt C. Vercauteren, Henry Campa Iii, William R. Clark, Justin W. Fischer, Scott E. Hygnstrom, Nancy E. Mathews, Clayton K. Nielsen, Eric M. Schauber, Timothy R. Van Deelen, Scott R. Winterstein

United States Department of Agriculture Wildlife Services: Staff Publications

Variation in the size of home range of white-tailed deer (Odocoileus virginianus) has broad implications for managing populations, agricultural damage, and disease spread and transmission. Size of home range of deer also varies seasonally because plant phenology dictates the vegetation types that are used as foraging or resting sites. Knowledge of the landscape configuration and connectivity that contributes to variation in size of home range of deer for the region is needed to fully understand differences and similarities of deer ecology throughout the Midwest. We developed a research team from four Midwestern states to investigate how size of …

Survival And Cause-Specific Mortality Of Wild Turkeys In Northern Indiana, Lee A. Humberg, Travis L. Devault, Olin E. Rhodes Jr.

United States Department of Agriculture Wildlife Services: Staff Publications

Information regarding survival and cause-specific mortality of eastern wild turkeys (Meleagris gallopavo silvestris) is vital to their management, especially in small or isolated populations. Between January 2003 and August 2005, we used radio telemetry to investigate survival and cause-specific mortality of 87 [44 male (24 adult and 20 juvenile) and 43 female (34 adult and 9 juvenile)] wild turkeys in northern Indiana. We estimated annual and seasonal survival using the Kaplan-Meier product-limit method. Mean male and female annual survival estimates were 0.257 and 0.777, respectively. Annual survival estimates were different between sexes within years, but were homogenous within …