Digital Commons Network^™

The Effects Of Mathematics Methods Courses On The Mathematical Attitudes, Content Knowledge, And Pedagogical Beliefs Of Preservice Teachers, Robert John Quinn

UNLV Retrospective Theses & Dissertations

This study investigated the effects of mathematics methods courses on the mathematical attitudes, content knowledge, and pedagogical beliefs of preservice elementary teachers and preservice secondary mathematics teachers. The study was conducted during the fall semester of 1992 at the University of Nevada, Las Vegas. Forty-seven preservice teachers participated voluntarily. Twenty-eight were enrolled in an elementary mathematics methods course; nineteen were enrolled in a secondary mathematics methods course; Attitudes toward mathematics were studied quantitatively by administering Aiken's Revised Attitude Scale on a pretest-posttest basis. The results indicated that the attitude toward mathematics of preservice elementary teachers improved significantly. The attitude toward …

Time Management Behaviors Of Single Parent Women Educators At A Two-Year College, Kenneth Harold Steidel

UNLV Retrospective Theses & Dissertations

Case study methodology was utilized to examine and describe time management behavior of single parent women educators at a two-year college. A non-probability, stratified sample of convenience (Snowball Sampling) where participants were referred by colleagues, friends, and other participants processed and determined final selection of three subjects for the case studies. The three participants selected for the study were single parent women, between the ages of 35 and 45, teaching full-time at a two-year college, with no more than two children living at home. The children were all teenagers attending either junior or senior high schools. Each participant had been …

The Restructuring Of A Rural Utah High School, Larry K Shumway

UNLV Retrospective Theses & Dissertations

The Restructuring of a Rural Utah High School was a case study which explained the setting and the events related to the restructuring of North Sevier High School in Salina, Utah from 1989-1992. The purpose of the study was to identify issues and problems in restructuring which could provide insight for school leaders of for policy makers in education. Data for the study was collected by interviewing participants in the restructuring project including teachers, community members, board members, and district administrators. The researcher was the principal of the school at the time of the events of the case and at …

Trace Element Analysis Of Selected Springs In The Virgin River Basin, Mary Ann Yelken

UNLV Retrospective Theses & Dissertations

Spring water from 23 springs in and near the Virgin River Basin (southwestern Utah, northwestern Arizona, and southeastern Nevada) was collected and analyzed for chemical concentrations. Trace elements and major ion chemistry was used to determine the potential for utilizing water chemistry to provide information on spring water source and flow pathways. Principal Component Analysis (PCA), rare earth element (REE) normalization patterns, and mineral equilibrium modeling (PHREEQE) techniques were used to analyze the data set. Four major spring water groups were displayed by the PCA, based on similarities in water chemistry. The analyses suggest that spring water chemistry is a …

Inversion Of Input/Output Map, Sliding Mode And Nonlinear Flight Control System Design, James J. Romano

UNLV Retrospective Theses & Dissertations

We present the review of two approaches for control system design. These are: (i) Non-Linear Inverse Dynamics and (ii) Variable Structure Control; These two schemes of design are applied to a realistic aircraft flight model. The equations of motion are highly nonlinear and the design of a control system for large roll-coupled maneuvers is not a simple task. Analytical derivations of control laws are presented in this thesis for the maneuver of the aircraft using inversion and variable structure control techniques. A short theoretical treatment of each technique is developed and their applications to flight control design are presented; Several …

Register Allocation And Optimization Techniques In Compiler Construction, Edward R. Jorgensen

UNLV Retrospective Theses & Dissertations

The purpose of this thesis was to investigate the implementation of register allocation and optimization techniques used in the process of compiler construction. The implementation issues were investigated by choosing an architecture and examining various register allocation and optimization techniques. In choosing the techniques to be implemented, only the most promising possibilities were explored for the specific architecture chosen. The goal was to categorize the register allocation and optimization schemes for the architecture.

Gas Chromatography/Fourier Transform Infrared Spectroscopy/Mass Spectrometry For Environmental Analysis: A Quick Turnaround Method For The Analysis Of Polycyclic Aromatic Hydrocarbons, Irene Marie Farnham

UNLV Retrospective Theses & Dissertations

Two methods for organic analysis of environmental samples are discussed. The quantitative capabilities of a gas chromatograph/Fourier transform infrared spectrometer/mass spectrometer were investigated. Three methods of quantitation using FT-IR were examined. These methods were: the Gram-Schmidt method, maximum absorbance method and the integrated absorbance method. The results were compared to those obtained from the mass spectrometer operating in the single and total ion mode. The effect that injection volume has on quantitation was also investigated. Injection volumes of up to 100 uL were introduced to the GC/FT-IR/MS system using a large retention gap which preceded the analytical column; This report …

Today's Racism And Black Frustrations, Ernest Elmo Clark

UNLV Retrospective Theses & Dissertations

This Ethics and Policy Studies project is about America's present attitudes and policies towards blacks, and their frustrations because of racism. I intend to analyze the structure and operation of racism, and how it frustrates black Americans. Particular attention will be directed towards the pluses and minuses of black progress in America, as blacks became an integral part of Western culture; Will blacks be (across the board) accepted in American society, and if so, when? Of what must the moral and legal climate for a full citizenship be comprised? The problem is that racist and prejudicial acts still exist in …

The Influence Of Diet On Growth Rate, Thyroid Hormone Output, And Thermoregulation In Laboratory White Rats, Linda Susan Vanden Heuvel

UNLV Retrospective Theses & Dissertations

The physiological effects of the consumption of diets varying in protein and calorie content was assessed using young male Sprague-Dawley rats. Food intake (FI), water intake (WI), body weight (BW), rectal temperature (Tre), oxygen consumption (VO{dollar}\sb2{dollar}), hematocrit (Hct), Hemoglobin (Hb), plasma protein concentration (PP), and plasma levels of thyroxine (T{dollar}\sb4{dollar}), triiodothyronine (T{dollar}\sb3{dollar}), free thyroxine index (FT{dollar}\sb4{dollar}), and thyroid stimulating hormone (TSH) were measured. Food intake expressed per g BW was highest in the LP (5% protein) diet group, but body weight gain was the lower in the LP fed group compared to the Control group (22.5% protein). Decreases in dietary …

Modeling Of The Unlv-Aro Light-Weight Robot Using Lagrange's Assumed Mode Method, Symbolic Manipulation, And Numerical Simulation, Edward Yuk-Kam Lam

UNLV Retrospective Theses & Dissertations

This thesis modeled the dynamics of the UNLV-ARO serially connected light-weight robot. The two outer-most links of the robot exhibited flexible behavior in the in-plane and the out-of-plane directions. Lagrangian mechanics were used to model this system. Assumed modes method was used to approximate the vibration mode shape of the links. Using these analytical techniques in conjunction with the inverse dynamics method, a set of equations of motion was formulated to describe the vibrations of the robot. Due to the complexity of the system, the equations of motion were derived using MACSYMA, a symbolic software. From MACSYMA, the equations of …

A Multisubband Self-Consistent Two-Dimensional Numerical Model For Hemt Including Intersubband And Intrasubband Scattering Mechanisms In The Quantum Well, Helen Arman

UNLV Retrospective Theses & Dissertations

The previous one-subband model is extended to include transport of electrons in the quantum well with two subbands. The two higher moments of Boltzmann Transport Equations are solved for the two lowest subbands and the bulk system. The Schrodinger's and Poisson's Equations are solved self-consistently. The wavefunctions obtained are used to calculate the ionized impurity and the polar optical-phonon scattering mechanisms. The scattering rates obtained are in good agreement with those reported by Yokoyama and Hess. Coupling terms between the two subbands in the quantum well and the bulk system are derived from the scattering rates; We obtain lower transconductance …

Output Feedback Rotational Maneuvers And Vibration Damping Of Nasa Scole System By Inversion Theory, Misbahul Azam

UNLV Retrospective Theses & Dissertations

We treat the question of large rotational maneuver and vibration stabilization of NASA Spacecraft Control Laboratory Experiment System (SCOLE). The mathematical model of SCOLE System includes the dynamical equations for rigid body slew maneuver and three dimensional vibration of the rigid space shuttle, the flexible beam and the reflector with an offset mass. The contribution of this thesis lies in the development of two control systems based on (i) Euler angles or (ii) angular velocity components as output variables for large rotational maneuvers and vibration suppression of the SCOLE System. Nonlinear inversion theory is used for the design. The design …

Determination Of Radium-226 In Drinking Water By Alpha Spectroscopy, Jae-Gu Choi

UNLV Retrospective Theses & Dissertations

A radiochemical procedure for determination of radium-226 (Ra-226) in drinking water was developed. The method involves concentrating radium by coprecipitation with barium sulfate; separating radium from barium and other alkaline earth metals by ion exchange; and electrodepositing radium onto stainless steel disc for radioactivity counting. The procedure requires the using a chemical yield tracer, Ra-223. Two methods for the preparation of Ra-223 from Ac-227 were studied. One method, which uses solvent extraction of radium with TTA/benzene, showed better results and took much less time in comparison to the other method which uses anion exchange, followed by co-precipitation of radium as …

Littoral And Limnetic Zooplankton Communities In Lake Mead, Nevada-Arizona, Usa, Patrick J. Sollberger, Larry J. Paulson

Publications (WR)

Zooplankton were collected from adjacent littoral and limnetic sites in Lake Mead, Nevada-Arizona, USA. Limnetic species dominated both littoral and limnetic zooplankton communities; littoral species rarely exceeded 2% of monthly total zooplankton densities. Low species richness of littoral taxa and high similarity in species composition between littoral and limnetic habitats appeared to result from uniform horizontal physical and chemical environments, due to horizontal mixing, and from the absence aquatic macrophytes. Significant differences in spatial distribution occurred in phytoplankton biomass, total zooplankton density, and fish "abundances; highest concentrations of these factors occurred nearest an inflow high in nutrients and progressively declined …

An Analytical Approach To Quantum Mechanical Tunneling Time In Electronic Devices, Prabhaharan Thanikasalam

UNLV Retrospective Theses & Dissertations

Starting from the analytical solution to the Time-Independent Schrodinger Equation, and exploiting the analogy between the transmission line equations and the time-independent Schrodinger wave equation, an analytical expression for the Average Particle Traversal (APT) time, {dollar}\tau\sb{\rm APT},{dollar} through a rectangular potential barrier region, under no bias, is derived, in terms of the barrier width, potential, and the incident energy of the electron. This approach is extended to derive an analytical expression for the APT time through a resonant tunneling structure, two symmetrical rectangular potential barriers sandwiching a potential well, under no bias. The results of the single potential barrier traversal …

Virtual Time Synchronization In Distributed Database Systems, Timothy E Lemaster

UNLV Retrospective Theses & Dissertations

Distributed systems synchronized by Virtual Time have been topics of recent interest. Virtual Time follows an optimistic philosophy relying on rollback for synchronization instead of abortion or blocKing Although many applications have been suggested as candidates for Virtual Time, few were simulated or implemented. This research reports on the first implementation and results of a Distributed Database Management System synchronized by virtual time. We argue that virtual time is a viable alternate concurrency control method for distributed database systems if its memory overhead can be absorbed.

Goodsprings: A Historical Archaeological Review Of The Yellow Pine Mining District, Christina A Miller

UNLV Retrospective Theses & Dissertations

This thesis consists of a comparative analysis of the written historical record and surface archaeological features relevant to three mines of the Yellow Pine Mining District. The intent is to discover if field observations do indeed confirm historical documentation. Using archival sources combined with an intuitive non-random sampling method, various feature systems associated with mining were recorded in order to discern chronological and historical accuracy. Research questions concerning length of mining activities, number of men employed at the mines, feature systems utilized, and the current condition of each site were addressed to confirm documentation and the historical significance of these …

A Methodological Study And Forecasting Of Room Occupancy Trend In Las Vegas, William Weixia Wang

UNLV Retrospective Theses & Dissertations

The purpose of this research is to develop a systematic methodology for occupancy forecasting and to obtain the future occupancy trend for the Las Vegas hotel/motel industry; A systematic analytical model is developed for generic hotel/motel occupancy forecasting; The analytical model includes log-linear regression models and "other" extrapolation forecasting models for model parameter estimation and optimization; The model is applied to Las Vegas and the U.S. lodging occupancy data from 1973 through 1990 and is used to forecast Las Vegas and the U.S. room occupancies from 1991 through 1993.

Determinants Of The Structural Niches Of Columnar Cacti In The Southwest, Joseph George Hentz

UNLV Retrospective Theses & Dissertations

I evaluated whether morphological differences among populations of Carnegiea gigantea and Pachycereus pringlei actually represent evolutionary adaptation, different developmental responses to the environment, or simply differences in population age structure. Populations of Carnegiea running east to west across southern Arizona differ primarily in size structure, not in growth form. Where growth form differences do exist, they are correlated with variation in aridity. Carnegiea and Pachycereus in less xeric environments have more branches, greater total branch length, and earlier initiation of branching than those of equal height in more xeric environments. I found no evidence of evolutionary divergence among Carnegiea or …

The Severed Son And Other Poems (Original Writing), Angela Sue Witzke Andersen

UNLV Retrospective Theses & Dissertations

This poetry speaks of people in and of their many dimensions. I don't set out with any one purpose when I write--that would smother the poem--but if there is one thing I am seeking, it is honest portrayal, the truth of the feeling; As far as the creative process is concerned, I let the poem come, with all its sounds, plays on words, multiple meanings. I let it form into its own mode and tone, and then I look at it, listen to it. Sometimes a poem requires little revision, sometimes it requires much revision, but in the process, I …

Political Culture And Water Politics In Nevada: Las Vegas Attempts To Quench Its Thirsts, Andrea Kristen Gerlak

UNLV Retrospective Theses & Dissertations

Today it is clear that the issue of water and its unavoidable scarcity in many areas has secured a permanent place on the public policy agenda. Certainly in Las Vegas, Nevada the rapid population growth, great economic development and extreme arid climate make the region vulnerable to the dangers of a water shortage. While some estimates suggest that Las Vegas will use all of its water by 1997, Las Vegas appears to be unprepared to deal with the challenge of water scarcity. This lack of real planning and conservation has led to the Las Vegas Valley Water District's "water grab", …

Enigmatic Commercials: Schema Distortion In Television Advertisements, Micheal Shane Schneweis

UNLV Retrospective Theses & Dissertations

In an effort to increase attention and recall, advertisers have begun to use commercials that employ schema distortion that make the commercial seem enigmatic to the viewer. Recently, research in communication, specifically the news media, has focused on the processes of learning and recall using schema theory; The method used 12 commercials, 6 identified as enigmatic and 6 identified as non-enigmatic. The non-enigmatic commercials were similar in style to the enigmatic. A questionnaire and an edited videotape were developed to examine three areas of schema theory as it related to television commercials: recall, emotional reaction and the ability of viewers …

Direct Determination Of Molecular-Orbital Symmetry Of H2s Using Polarized X-Ray Emission, R. Mayer, Dennis W. Lindle, S. H. Southworth, P. L. Cowan

Chemistry and Biochemistry Faculty Research

X-ray emission from the molecule H₂S is strongly polarized following excitation of a sulfur K-shell electron to an unoccupied subthreshold molecular orbital with a polarized x-ray beam. Changes in the polarization of the emission spectrum are observed as the incident beam's energy is swept across the subthreshold absorption resonance. The previously unresolved absorption resonance is shown experimentally to be primarily associated with a molecular orbital of b₂ symmetry, but with a high-excitation-energy component due to an orbital with a₁ symmetry. Satellite emission intensity is shown to depend on the primary photon energy and is therefore associated …

Lake Mead Nutrient Enhancement Project, Peter D. Vaux, Larry J. Paulson, Nevada Department Of Wildlife, National Oceanic And Atmospheric Administration

Publications (WR)

The Lake Mead Fertilization Project is a research program designed to investigate the potential for using large-scale artificial fertilization to enhance the game fisheries of this reservoir through an increase in the population of threadfin shad, the system's primary forage species. A substantial decline in the population of largemouth bass, together with poor condition of adult striped bass, are the two major issues affecting the Lake Mead game fisheries. Both issues have been hypothesized to be a result of an inadequate amount of forage in the reservoir. Previous studies have in turn suggested that a major factor limiting the shad …

Hydrogeology And Hydrogeochemistry Of The Shallow Alluvial Aquifer Zone, Las Vegas Valley, Nevada, Harry Stephen Wild Jr.

UNLV Theses, Dissertations, Professional Papers, and Capstones

In Las Vegas Valley, Nevada, the shallow alluvial aquifer zone is a possible source of contamination to the principal alluvial aquifers that provide 30% of the public drinking water supply for the valley. Development of the principal aquifers has lowered pressure head in the principal aquifers and created the potential for downward seepage from the shallow aquifer zone. This study was undertaken to characterize the hydrogeology and hydrogeochemistry of the shallow alluvial aquifer zone and to compare the hydrogeochemistry of the shallow and principal alluvial aquifer zones.

A 37 well shallow ground water monitoring network was established and water-level, water-quality, …

Argon-Photoion–Auger-Electron Coincidence Measurements Following K-Shell Excitation By Synchrotron Radiation, Jon C. Levin, C. Biedermann, N. Keller, L. Liljeby, C.-S. O, R. T. Short, Ivan A. Sellin, Dennis W. Lindle

Chemistry and Biochemistry Faculty Research

Argon photoion spectra have been obtained for the first time in coincidence with K-LL and K-LM Auger electrons, as a function of photon energy. The simplified charge distributions which result exhibit a much more pronounced photon-energy dependence than do the more complicated noncoincident spectra. In the near-K-threshold region, Rydberg shakeoff of np levels, populated by resonant excitation of K electrons, occurs with significant probability, as do double-Auger processes and recapture of the K photoelectron through postcollision interaction.

Experimental Apparatus For Production, Cooling, And Storing Multiply Charged Ions For Charge-Transfer Measurements, Victor H. S. Kwong, T. T. Gibbons, Z. Fang, Jinhua Jiang, H. Knocke, Yingtao Jiang, B. Ruger, Su-Ching Huang, E. Braganza, W. Clark, L. D. Gardner

Electrical & Computer Engineering Faculty Research

A novel method is described that combines the production of ions by laser ablation with an ion‐trap technique for the measurement of thermal‐energy charge‐transfer rates of multiply charged ions and neutrals. The charge‐transfer rate is determined by measuring the rate of loss of stored ions from the trap. Verification of the calibration of the apparatus is demonstrated through investigation of charge transfer of N₂ and N²⁺, which has been studied by another group. We also have made the first measurement on the thermal‐energy charge‐transfer coefficient of Ar and W²⁺. The rate coefficient is 0.99(0.22)×10^{−11 …}

Enhancement And Monitoring Of The Procambarus Clarkii Population In Lake Mead, Mikell Beth Hager

Publications (WR)

Procambarus clarkii are found in extremely low numbers throughout Lake Mead, AZ-NV. The crayfish are an important dietary component for game fish. Enhancement of the crayfish population would broaden the fishery forage base. Crayfish were stocked and monitored in a study cove on Saddle Island to determine if the Procambarus clarkii population could be enhanced. A trapping survey of the area after the following reproductive season yielded low numbers of crayfish. A comparison of pre-stocking and post-stocking catch per trap day (CPTD) values revealed no significant increase in the population. Procambarus clarkii growth is limited by environmental factors in Lake …

Stromatolites Of The Lower Cambrian Deep Spring Formation; Mount Dunfee, Esmeralda County, Nevada, Lynn Oliver

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Middle Member of the Lower Cambrian Deep Spring Formation at Mount Dunfee, Nevada contains a diverse assemblage of stromatolites that formed on a tide- and storm-dominated, siliciclastic-influenced, carbonate shelf. The stromatolites formed in a shallow subtidal environment within and near active oolite shoals under strongly focused currents. The stromatolites occur in four different lithofacies: (1) bioherms of digitate stromatolites, (2) bioherms and biostromes of inclined stromatolites, (3) isolated forms of massive and hemispheroidal stromatolites, and (4) a biostrome of cryptomicrobial boundstones. The first three lithofacies are interpreted as microbial reefs. They had topographic relief, formed in active agitated waters, …

Pms And Eosinophilia-Myalgia Syndrome, Mary Guinan

School of Public Health Faculty Research

No abstract provided.