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Late-Holocene Earthflows Of The Willard Playa/Dune Complex, Estancia Valley, New Mexico: A Geomorphic Response To Climatic Change, Kurt A. Goebel

UNLV Theses, Dissertations, Professional Papers, and Capstones

Late-middle to late Holocene dune sediment that overlies Pleistocene lacustrine sediment marks the onset of xeric conditions in the Estancia Valley, central New Mexico. Incised into the underlying lacustrine sediments, the modern deflation basins are enclosed by parabolic dunes composed of clay and gypsum derived from the underlying sediment.

Located on the in-facing dune slopes of the deflation basins, the most striking geomorphic feature of this dune complex are numerous elongated scars. These relict scars document a geomorphically distinct earthflow event. Arroyos that cut into flow scars expose eolian earthflow sediment overlying lacustrine deposits. In the zone of depletion, erosional-flow …

The Geology And Structural Significance Of The Arch Mountain Area, Northern Black Mountains, Mohave County, Arizona, Edward Eschner

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Arch Mountain area of northwestern Mohave County, Arizona, is typified by rocks that range from Precambrian to Quatemary in age. Arch mountain is a north-trending horst bounded on the west by the Petroglyph Wash graben and on the east by the Virgin Basin. A low-angle normal fault, herein named the Arch Mountain detachment fault, is exposed for 6 km along strike just below the ridge crest of Arch Mountain, and it is typified by a 2-20 cm thick zone of hematite-impregnated breccia and cataclasite. The detachment fault places an upper plate of Precambrian gneiss, Paleozoic quartzite, shale and dolomite, …

A Two-Dimensional Numerical Model Of The High Electron Mobility Transistor, Sze-Him Ng

UNLV Retrospective Theses & Dissertations

A two-dimensional numerical model of the high electron mobility transistor (HEMT) with consideration of quantization in the channel is presented. In this model, the spatial spread of the electron concentration in the quantum well normal to the heterojunction is taken into consideration by solving Schrodinger's and Poisson's equations self-consistently. The Boltzmann transport equation in the form of a current continuity equation and an energy transport equation is solved to obtain the transient transport behavior. Transport of carriers takes place in two layers in the GaAs region: the lowest subband of the quantum well and a non-quantized bulk layer; The simulation …

The Limits To Openness: The Impact Of Glasnost' And Perestroika On The Baltic Republics, Susan Faye Davis

UNLV Retrospective Theses & Dissertations

The Baltic Republics occupy a unique position within the Soviet Union. They are the most Western, the most industrialized, the most efficient and the most productive of all Soviet republics. As such, they epitomize the goals of Gorbachev's reforms. If the leadership were to crack down on the current manifestations of nationalistic unrest and on the recently established quasi-political popular organizations in the Baltic, the result would be a chilling effect on the entire reform process. Therefore, the Baltic Republics, as long as their goal remains the support of perestroika, are being allowed to advance previously unacceptable demands including autonomy …

Structural Analysis And Design Of A Flexible Three-Link Hydraulically-Actuated Robotic Arm, Tarek Mitri Bannoura

UNLV Retrospective Theses & Dissertations

The structural design of a flexible three-link hydraulically activated robotic mechanism is presented. Static and quasi dynamic, three-dimensional analysis of the robotic mechanism is shown. Force and deflection equations are derived for the robotic mechanism and the finite element analysis is used to model its dynamic behavior and to study the fundamental 3-D bending and twisting frequencies of the arm as it reaches various positions inside the workspace. Using beam-column theory and finite element method, the design of a flexible three-link robotic mechanism is shown. The flexibility of the arm is set so that the total deflection of the arm …

The Comparison Of Physical Fitness Between Type Ii Diabetics And The Apparently Healthy Population, Joan Kathleen Macdonald

UNLV Retrospective Theses & Dissertations

Physical fitness was measured in a Type II diabetic population and compared to apparently healthy men and women. Eighty-eight female Type II diabetics, aged over 40 years were compared to 2,008 normal females of the same age, and 138 male Type II diabetics were similarly compared to 2,271 normal males. The National YMCA physical fitness test battery was used to measure fitness which consisted of flexibility, muscular strength and endurance, cardiorespiratory fitness, body composition, and resting values of heart rate and blood pressure. Differences in the mean values of each parameter were tested for significance (p {dollar}<{dollar} 0.05) using the Z x test. Although significant differences were found in VO2 max and PWC max in both males and females, the results were conflicting. Since significant differences in most fitness variables existed, it must be assumed that Type II diabetics do not belong to the apparently healthy population fitness wise, therefore, norm tables should be developed for Type II diabetics. (Abstract shortened with permission of author.).

Laboratory Investigation Of A Method For Determining In Situ Saturated Hydraulic Conductivity, Joel Stacey Hayworth

UNLV Retrospective Theses & Dissertations

A study was conducted to determine the applicability of a method for determining in situ saturated hydraulic conductivity in porous media. This method requires an accurate measurement of the horizontal port water speed through a section of a borehole packed with a porous material of known hydraulic conductivity. Analytical expressions describing the theoretical basis for the method were investigated, as was the sensitivity of these expressions to varied parameters; Experiments were designed and performed in an attempt to determine if the theory could be successfully applied in a laboratory setting. These experiments were conducted in a large flowchamber which simulates …

Analysis Of Acoustics In Heating, Ventilation And Air Conditioning Systems, Jeffry Michael Bledsoe

UNLV Retrospective Theses & Dissertations

The analysis of acoustics in heating, ventilation and air conditioning systems is presented. The objective of this ASHRAE funded (ASHRAE TRP 556) project was to present the HVAC designer with a set of algorithms for determining the acoustical characteristics of heating, ventilation and air conditioning systems that are useful and reliable. All algorithms are based on current verifiable published and available unpublished test results. (Abstract shortened with permission of author.).

The Relationship Between Suicidal Phenomena And Depression, Dysfunctional Attitudes, Irrational Beliefs, And Hopelessness, Shonna L Erickson

UNLV Retrospective Theses & Dissertations

The study of depression and suicidal phenomena among adolescents has lagged behind that of adults. Very few studies have examined attitudes and beliefs of relevance to cognitive therapy among suicidal adolescents. In this study 40 incarcerated juvenile females were administered the Beck Depression Inventory (BDI), the Dysfunctional Attitude Scale (DAS), the Irrational Beliefs Test (IBT), and the Hopelessness Scale (HS). A stepwise discriminant analysis identified seven variables which significantly differentiated the suicidal from the nonsuicidal group. These variables were number of previous attempts, the HS, DAS, subscales 4, 5, and 8 of the IBT (Frustration reactive, emotional irresponsibility, and dependency, …

Field Comparison Of Groundwater Sampling Methods, Ronald Paul Blegen

UNLV Retrospective Theses & Dissertations

Most ground-water sampling methods require the investigator to purge a large quantity of stagnant water from a well prior to collecting a sample. The use of in situ ground-water sampling devices which minimize or eliminate the need for purging would help to alleviate these problems. In this field comparison study, the performances of seven ground-water sampling devices, including two in situ sampling systems, were evaluated to determine if these devices would yield accurate, precise, and representative data. The sampling devices included a bladder pump, a bladder pump below an inflatable packer, a bailer, the Westbay{dollar}\sp\circler{dollar} Mp System, two in situ …

Comparison Of The Sodium Ion Channel Densities, The Water Flux Changes, And The Membrane Capacitance Changes In The Pelvic And Pectoral Skin Of The Toad, Bufo Woodhousei, Cathleen Ann Baker

UNLV Retrospective Theses & Dissertations

The amphibian antidiuretic hormone arginine vasotocin (AVT) stimulated osmotic water flow (JH{dollar}\sb2{dollar}O) across isolated skin from the pelvic but not the pectoral region of the toad, Bufo woodhousei. The apical membrane capacitance (C{dollar}\sb{\rm a}{dollar}) of the cells in the stratum granulosum of neither skin region was changed by AVT treatment when an osmotic gradient was present across the tissue; Short circuit current (I{dollar}\sb{\rm sc}{dollar}) and the amiloride sensitive current (I{dollar}\sb{\rm Na\sp+}{dollar}) both increased significantly in the pelvic and in the pectoral skin after AVT treatment, but to a larger degree in the pelvic skin. If M is expressed as a …

Development Of A Tool To Investigate Factors Related To Job Satisfaction In Geriatric Nurses, Mary-Jane Snyder Araldi

UNLV Retrospective Theses & Dissertations

The purpose of this study was to develop and assess a three part semantic differential instrument to measure job satisfaction of geriatric nurses based on an adaptation of Dorothy Johnson's conceptual framework. A sample of 306 geriatric nurses who were members of the American Nurse's Association responded to a 4-page, mailed questionnaire (return rate 37%). The questionnaire developed consisted of four parts: Sociodemographic data, and three semantic differential scales assessing, Attitudes toward geriatric nursing, Attitudes toward the work environment, and Attitudes toward the administrator. Descriptive statistics were compiled for sociodemographic variables; Results of the regression analyses demonstrated that job satisfaction, …

Dynamic Analysis Of Rotating Fan Structures By The Finite Element Method, Mohamed Said Rouas

UNLV Retrospective Theses & Dissertations

The Finite Element Method is used to determine the fundamental mode shapes and frequencies of fan structures. The analysis is performed on five fan structures, having different geometries, under static conditions and under centrifugal forces at various angular velocities. The results of the analysis are correlated with experimental data. The Southwell Coefficient, which takes into account the effect of centrifugal stiffening/softening, is determined for each fan and used for the prediction of its dynamic response and critical speeds. The research led to a study of the influence of riveted spider-to-blade connections on the vibration response of propeller fans; This thesis …

Survival Of Ice Nucleation-Active And Genetically Engineered Inactive Strains Of Pseudomonas Syringae, Mark P Buttner

UNLV Retrospective Theses & Dissertations

The survival of ice nucleation-active (INA) and genetically engineered non-INA strains of Pseudomonas syringae was compared under starvation and freezing conditions. In starvation experiments, both strains displayed similar survival curves and recovery from starvation was nearly identical for the two strains. In freezing experiments, oat seedlings colonized by each strain were subjected to freezing temperatures. Populations of the INA strain increased 15-fold in the 18 hours after oat plants incurred frost damage at {dollar}-{dollar}5 and {dollar}-{dollar}12{dollar}\sp\circ{dollar}C. Plants colonized by the non-INA strain were undamaged at {dollar}-{dollar}5{dollar}\sp\circ{dollar}C and exhibited no changes in population size. As temperatures were lowered, plants colonized by …

Petrogenesis Of Late Cenozoic Alkalic Basalt Near The Eastern Boundary Of The Basin-And-Range: Upper Grand Wash Trough, Arizona And Gold Butte, Nevada, Erin D Cole

UNLV Retrospective Theses & Dissertations

Geochemical, isotopic, paleomagnetic, and geochronological studies of Late Miocene to Pliocene alkalic basalt in the upper Grand Wash Trough, Arizona and at Gold Butte, Nevada may place constraints on the petrogenetic history of the basalt and on the geometry of the crustal structures that may have served as conduits; Geochemical modelling suggests that type B basalt can be derived from independent batch melts of spinel peridotite with limited fractionation (5 to 9% olivine plus Fe-Ti oxide); The Sr, Nd and Pb isotopic data confirm the geochemical models and indicate that all three magma types are mantle derived; The restricted range …

Maximum Oxygen Uptake Predicted From Submaximal Tests, Anne Renee Lindsay

UNLV Retrospective Theses & Dissertations

Two widely used tests for predicting max VO2 are the Astrand-Ryhming Nomogram (ARN) and the National YMCA bicycle ergometer test. While both tests predict max VO2 from heart rate and workload, the ARN also uses submaximal oxygen uptake as a parameter; The purpose of this study was to determine which of the 3 types of exercises used with the Astrand-Ryhming nomogram predicted max VO2 most accurately; Thirty subject's between the ages of 18 and 35 performed maximally on a treadmill and bicycle ergometer. Oxygen uptake and heart rate were measured at both maximal and submaximal workloads using open circuit spirometry …

Drinking-Driving And Social Control: An Analysis Of Peer Intervention, Michael David Collins

UNLV Retrospective Theses & Dissertations

The present study contends that legislative sanctions, regardless of severity, cannot sufficiently curb the drunken driver unless they are met with the concern of an equally sanctitive public (Formby and Smykla, 1984). The explicit goal of research presented here is to report the extent and power of peer sanction surrounding potential drinking and driving situations. This goal consists of the following components: (1) to discern whether individuals are at all inclined to attempt intervention in situations of potential drunken driving, and if so, to ascertain the types of intervention techniques attempted as well as intervention settings; (2) to determine which …

Decoupling And Adaptive Control And Stabilization Of Two-Link Elastic Robotic Arm, Arijit Das

UNLV Retrospective Theses & Dissertations

In this thesis the control and stabilization of a two link flexible robotic arm is considered. The first scheme is based on nonlinear inversion, a nonlinear controller is designed for the trajectory control of the joint angles using joint torquers. The inverse controller includes a servocompensator for robustness. A simplified controller has also been designed neglecting the Coriolis and Centrifugal forces; In the second scheme the control system design is based on nonlinear adaptive control and linear stabilization. First a nonlinear adaptive control law is derived such that in the closed-loop system the joint-angles are precisely controlled to track reference …

Initial Deposition In The Sevier Foreland Basin Of Southern Nevada: Conglomerates Of The Cretaceous Willow Tank Formation, Clark County, Nevada, Julie Ann Reese

UNLV Retrospective Theses & Dissertations

The basal conglomerate of the Willow Tank Formation is the initial foreland basin sediment that was derived from highlands created by the Sevier thrust belt and dispersed across an irregular surface of Jurassic Aztec Sandstone in southern Nevada. The conglomerate varies from 5.5 to 34.5 m in thickness and is composed of two compositionally distinct units. The lower conglomerate is composed of Precambrian and Ordovician metaquartz-arenites, and Triassic and Jurassic sedimentary clasts, and its sandstone interbeds and matrix are chert-arenite. This unit represents the initial uplift and erosion of the Gass Peak and William Tank thrusts. The predominance of Paleozoic …

Variable Structure And Ultimate Boundedness Control And Stabilization Of Flexible Robotic Systems, Perumal Jegan Nathan

UNLV Retrospective Theses & Dissertations

In this thesis we study the control of two link light weight elastic manipulator in the presence of uncertainty. The control of flexible robotic arm with uncertainty such as variable payload, joint angle frictional torque etc., is an interesting and important problem; Here we consider control of joint angles and stabilization of the flexible modes caused by the manuever of robotic arm by two methods. These are: (i) Variable Structure control and (ii) Nonlinear Ultimate Boundedness control. Nonlinear Ultimate Boundedness control is a continuous control wherein the joint angle tracking error is uniformly ultimately bounded in the closed-loop system; Analytical …

Sampling Inner Experience In Adolescents, Lois Christina Monson

UNLV Retrospective Theses & Dissertations

The inner experience of five adolescents, ages 12 through 14, has been investigated through an experience-sampling method that asked the subjects to describe in detail the inner experience that was ongoing at randomly sampled moments during their daily living. A beeper signaled the subject to freeze their inner experience, (i.e., thoughts, feelings, images, etc.) at the moment of the beep. Findings indicated, as had been found in previous research with adults, that adolescents had a variety of inner experience including Images, Inner Speech, Inner Hearing, and Feeling. Adolescents, unlike adults, reported the slow forming and fading of Images, leading to …

Measurement Of The Dependence Of The Averaged Internal Mode On The Scattering Vector And Of The First Internal Mode On The Concentration Of Polystyrene In Solution Using Photon Correlation Spectroscopy, Johannes Klaus Schaller

UNLV Retrospective Theses & Dissertations

A study of the internal behavior of polystyrene in toluene and cyclohexane was done using photon correlation spectroscopy. In the experiments laser light of two different wavelengths was scattered from local concentration fluctuations in the polymer and autocorrelation function was calculated; The autocorrelation function can be written as a sum of decaying exponentials. The center-of-mass mode with a decay constant Dq{dollar}\sp2{dollar} is contained in every mode. D is the polymer diffusion coefficient and can be measured in low angle light scattering experiments and q is the magnitude of the scattering vector. Thus this center-of-mass mode can be factored out of …

Israel And The Occupied Territories: An Analysis Of The Israeli-Palestinian Conflict, Benjamin Wood

UNLV Retrospective Theses & Dissertations

This thesis will consist of six chapters. An introductory chapter will explore various conflict theories and their relevance to the situation which exists in the occupied territories. Chapter two examines the historical dimensions of the West Bank problem by focusing on the Jordanian role in the West Bank prior to the Six Day War. In the third chapter, the present political conditions under the Israeli Military Government is discussed as well as the positions taken by the Labour Party, the Likud coalition and the smaller parties within Israel. The role of the P.L.O. and moderate Palestinian mayors within the occupied …

The Rehydration Behavior Of The Desert Toad, Bufo Punctatus, Dona Rae Brekke

UNLV Retrospective Theses & Dissertations

The red spotted toads, (Bufo punctatus), demonstrate a "water absorption response" (WR) in which they aduct the hindlimbs and press the ventral skin to a moist surface. Associated with the WR, toads showed three characteristic behaviors: (a) moves, in which the toads would systematically move to adjacent regions of the moist surface to optimize water gain; (b) settles, in which a toad would laterally oscillate its body to maximize contact area when showing the WR; and (c) kicks, in which toads would rub adherent particles from the skin with the hind feet; Measurements of the capacitance of the ventral skin, …

Object-Oriented Data Modeling, Donald W Baltz

UNLV Retrospective Theses & Dissertations

The object-oriented paradigm models local behavior, and to a lesser extent, the structure of a problem. Semantic data models describe structure and semantics. This thesis unifies the behavioral focus of the object-oriented paradigm with the structural and semantic focus of semantic data models. The approach contains expressive abstractions to model static and derived data, semantics, and behavior. The abstractions keep the data model closer to the problem domain, and can be translated into a relational (or other) implementation. The paper makes six contributions. First, a comprehensive set of data structuring abstractions are described. Second, the abstractions are compared to the …

The Dynamic Response Of A Flexible Three-Link Robot Using Strain Gages, Lagrange Polynomials, Fourier Series, And The Finite Element Analysis, Robert Frank Marceau

UNLV Retrospective Theses & Dissertations

This thesis presents theoretical and experimental methods for determining the static and dynamic response, in three dimensional space, of a flexible three-link robotic manipulator. The Links are designed to deform elastically under static and dynamic loads. Lagrange polynomials are derived to determine the defected shape of the robotic links. All coefficients of the Lagrange polynomials are functions of the elastic strain at three specific locations on each link. Strains are converted to voltage differentials and are read into a micro-computer through an A-to-D board system, where they are converted to digital strain values. Coefficients defining the damped response of the …

Identifying Environmental Stressors Affecting Parents With An Infant In The Nicu, Donna Gaynelle Mattson

UNLV Retrospective Theses & Dissertations

To discuss sources of stress for parents, a convenience sample of 47 parents of infants admitted to a NICU was obtained to complete questionnaires pertaining to different possible sources of stress. The questionnaires included the Parental Stressor Scale: Neonatal Intensive Care Unit, State-Trait Anxiety Inventory, and Parent/Child Uncertainty in Illness Scale; The parents of preterm infants had higher mean scores for each of the PSS:NICU sub-scales than parents of full-term NICU infants with the difference significant for the sub-scale Role Alteration; The Parent/Child Uncertainty in Illness Scale was utilized in conjunction with the PSS:NICU to further validate the later instrument. …

Community Health Decisions: An Analysis Of A Grassroots Venture Into Citizen Participation In Health Care Policy Prioritization Issues, Michele Bonnee-Nichols

UNLV Retrospective Theses & Dissertations

Health care policymaking has been largely a closed system in which policymaking experts, special interest groups, and politicians have joined forces to decide what was best for the health care of the American people. This system has been shortsighted leading to severe long-range consequences on society; These critical forms of social consequence warrant this study of health care planning. Specifically, an analysis of a citizen-based grassroots venture, known as "Community Health Decisions," provides us a description of a civic participation movement into the health care political arena; It would appear that with the conclusions of this author, we might learn …

Hydrogeology And Hydrogeochemistry Of The Spring Mountains, Clark County, Nevada, Ronald Lee Hershey

UNLV Retrospective Theses & Dissertations

The Spring Mountains are the largest ground-water recharge area in southern Nevada and supply a significant amount of ground water to the Las Vegas' Pahrump, and Indian Springs Valleys; The high quality of ground water in the study area is controlled by the predominance of carbonate rock in the central portion of the mountain block. Modeling of {dollar}\delta\sp{13}{dollar}C in ground water suggest low P{dollar}\sb{\rm CO\sb2}{dollar} and enriched {dollar}\delta\sp{13}{dollar}C in soil, and open system conditions at high elevations. Analysis of {dollar}\sp{14}{dollar}C in ground water and geochemical modeling of ground water using PHREEQE and BALANCE suggest ground water from the Spring Mountain …

Colorimetric Determination And Speciation Of Arsenic With Silver Diethyldithiocarbamate, Daniel Carl Fischer

UNLV Retrospective Theses & Dissertations

The Silver Diethyldithiocarbamate (SDDC) Method is a widely used colorimetric technique for the determination of aqueous arsenic. The chemistry of the process is discussed in detail, and the method is compared to the other Environmental Protection Agency approved arsenic methods. Original modifications to the apparatus, allowing a more efficient reaction initiation are described. The observed detection limit of the improved procedure is 5 {dollar}\mu{dollar}g As/L (0.5 {dollar}\mu{dollar}g As). Due to the varied toxicity of arsenic compounds and oxidation states in the environment, speciation techniques are important. A review of the literature regarding the determination of individual arsenic species is presented. …