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Transient Temperature Distributions in a Thermally Orthotropic Plate With Non-Uniform Surface Heating (open access)

Transient Temperature Distributions in a Thermally Orthotropic Plate With Non-Uniform Surface Heating

ent temperature variation in a thermally orthotropic plate which is subjected to an arbitrary heating rate distribution along one face with all other surfaces being insulated. Dimensionless temperature histories and distributions determined from this solution are presented for the special, but representative, case of a linearly varying heating rate distribution on plates with varying degrees of thermal orthotropy. These results establish quantitatively the value of a material with high planar and low normal thermal conductivities for applications where it is desired to maintain minimum temperatures on the rear or unheated surface of a heat shield when the heated surface is subjected to a very non-uniform heating rate distribution. The applicability of simplifying assumptions in analyzing such a system is discussed. Experimental temperature measurements in a pyrolytic graphite plate heated by an oxyacetylene flame were made to verify the analytical results. Achievement of satisfactory agreement wss found to be dependent upon use of thermal property values differing from those presently available for this material. This is not unusual in that differences in production methods are known to introduce substantial property variations in anisotropic materials such as pyrolytic graphite. (auth)
Date: June 1, 1961
Creator: Hornbaker, David Ross
System: The UNT Digital Library
A Theoretical Study of the Transient Operation and Stability of Two-Phase Natural Circulation Loops (open access)

A Theoretical Study of the Transient Operation and Stability of Two-Phase Natural Circulation Loops

Mathematical models of the time-dependent behavior of two-phase natural- circulation loops were used to predict the operation and to explain the unusual instability sometimes observed. The initial results obtained for a loop similar to the Univ. of Minnesota loop were used to formulate a more complex and accurate model, and the predicted transient behavior was in close agreement with the experimental results from the Minnesota loop. For a 300psia, high-pressure loop, unstable oscillatory behavior was predicted under certain conditions and stable behavior under others. Closed unstable regions rather than limits were predicted, and the specifications of stability in terms of a single parameter were found to be impossible. The great difference in oscillatory frequencies observed at low and high pressures was found to be due largely to the system geometry. The criterion for the absence of oscillations was found to be similar to one of the criteria for stability of chemical reaction systems. (D.L.C.)
Date: June 1, 1961
Creator: Garlid, K.; Amundson, N. R. & Isbin, H. S.
System: The UNT Digital Library
Americium and plutonium in water, biota, and sediment from the central Oregon coast (open access)

Americium and plutonium in water, biota, and sediment from the central Oregon coast

Plutonium-239, 240 and americium-241 were measured in the mussel Mytilus californianus from the region of Coos Bay, OR. The flesh of this species has a plutonium concentration of about 90 fCi/kg, and an Am-241/Pu-239, 240 ratio that is high relative to mixed fallout, ranging between two and three. Transuranic concentrations in sediment, unfiltered water, and filterable particulates were also measured; none of these materials has an Am/Pu ratio as greatly elevated as the mussels, and there is no apparent difference in the Am/Pu ratio of terrestrial runoff and coastal water. Sediment core profiles do not allow accumulation rates or depositional histories to be identified, but it does not appear that material characterized by a high Am/Pu ratio has ever been introduced to this estuary. Other bivalves (Tresus capax and Macoma nasuta) and a polychaete (Abarenicola sp.) do not have an elevated Am/Pu ratio, although the absolute activity of plutonium in the infaunal bivalves is roughly four times that in the mussels.
Date: June 1, 1982
Creator: Nielsen, R. D.
System: The UNT Digital Library
Dynamic Simulation of Multi-Pass Pressurized Water Nuclear Power Plants by Analog Computer Techniques (open access)

Dynamic Simulation of Multi-Pass Pressurized Water Nuclear Power Plants by Analog Computer Techniques

A kinetic model of the primary loop of a multi-pass pressurized water reactor power plant is developed to evaluate, by analog computer techniques, the transient response characteristics under conditions of steam generator load and reactor control rod perturbations. Using the 2-pass 28 Mw(t) SM-2 reactor as a typical plant, transient behavior patterns are illustrated and examined for a variety of load inputs, variations in plant constants, and analog model simplifications. (auth)
Date: June 1, 1961
Creator: Brondel, J. O.
System: The UNT Digital Library
Dislocation morphology in deformed and irradiated niobium. [Neutron irradiation] (open access)

Dislocation morphology in deformed and irradiated niobium. [Neutron irradiation]

Niobium foils of moderate purity were examined for the morphology of dislocations or defect clusters in the deformed or neutron-irradiated state by transmission electron microscopy. New evidence has been found for the dissociation of screw dislocations into partials on the (211) slip plane according to the Crussard mechanism: (a/2) (111) ..-->.. (a/3) (111) + (a/6) (111).
Date: June 1, 1977
Creator: Chang, C. P.
System: The UNT Digital Library
Photoexcitation in Superconductors (open access)

Photoexcitation in Superconductors

Dissertation discussing the results of experiments to study the behavior of superconductors under light illumination.
Date: June 1976
Creator: Schuller, Ivan
System: The UNT Digital Library
Differences in Student and Faculty Attitudes toward Physical Activity (open access)

Differences in Student and Faculty Attitudes toward Physical Activity

The problem was to identify the differences in attitudes toward physical activity of students and faculty within a health, physical education, and recreation professional preparation program.
Date: June 1973
Creator: Judkins, Cleetis Wilburn
System: The UNT Digital Library
Texas Public School Library Media Specialists' Perceptions of the Use of the Internet in their Schools (open access)

Texas Public School Library Media Specialists' Perceptions of the Use of the Internet in their Schools

With the advent of the 21st century, technological innovations are transforming the face of education and the school library media center. One of these significant developments is the ability to communicate through the Internet. The purpose of this study is to examine the perceptions of Texas public school library media specialists who are active Internet users about their utilization of the Internet, and how their efforts in implementing and supervising Internet access in their school library media centers impact the Texas public schools that they serve. A survey instrument of Likert items was developed that queried these public school library media specialists for their perceptions of Internet use in their schools. MANOVA was the chosen statistical measure for this study. An initial electronic mail-out to 1,232 Texas public school library media specialists (K-12) with Internet addresses were contacted to participate in this study. After a time frame of one month, 196 Texas school library media specialists e-mailed the researcher, confirming their willingness to be a survey participant. All respondents to this e-mail request participated in this study, and a second U.S. mail-out was sent containing the actual survey instrument. The researcher found that the use of the Internet by school …
Date: June 1997
Creator: Bruns, Loretta A. (Loretta Ann)
System: The UNT Digital Library
A Study of Soil Erosion and its Control in the United States with Special Reference to Texas (open access)

A Study of Soil Erosion and its Control in the United States with Special Reference to Texas

A study of soil erosion in the United States, especially in Texas, which brings attention to the causes of soil erosion under the existing system of farm management. The material gathered and compiled and arranged under certail main heading. Two chapters deal with present and immediate causes of erosions and their results. One full chapter takes up the history of the conservation movement and attempts to show how slow Texans have been in comparison with some of the other states of the United States. The study calls for further research, teaching of better land-use, raising awareness of soil erosion causes and conditions.
Date: June 1939
Creator: Merrell, Jesse Byron
System: The UNT Digital Library
To Determine Whether or Not the Colleges of Texas are Preparing their Students of Industrial Arts to Teach Effectively in the High Schools of Texas (open access)

To Determine Whether or Not the Colleges of Texas are Preparing their Students of Industrial Arts to Teach Effectively in the High Schools of Texas

This is a study to determine whether the colleges of Texas are preparing their students of industrial arts to teach effectively in the high schools of Texas. The objectives of this study are to draw conclusions as to whether or not the colleges of Texas are preparing their students of industrial arts to teach effectively in the modern high schools; to show the training of industrial arts teachers; and to determine to what extent industrial arts are offered in the high schools of Texas.
Date: June 1939
Creator: Farmer, Joe Harold
System: The UNT Digital Library
A Survey of the Physical Education Programs for Girls in the Affiliated Schools within a Radius of Sixty Miles of Denton Texas (open access)

A Survey of the Physical Education Programs for Girls in the Affiliated Schools within a Radius of Sixty Miles of Denton Texas

A survey of the physical education programs for high school girls near Denton, Texas to determine the extent of compliance with state law for physical education, the facilities for the program, training of the teachers, type of physical education program, and teaching load of physical education teachers.
Date: June 1939
Creator: Morriss, May
System: The UNT Digital Library
Legal Status of Labor in Great Britain and the United States (open access)

Legal Status of Labor in Great Britain and the United States

An investigation of the legal status of labor in Great Britain and the United States. The basis of labor legislation is considered, and the development of labor legislation traced in both countries. A comparison of the legal status of labor at the present time in both countries is made. - Abstract
Date: June 1939
Creator: Richardson, Addran Dee
System: The UNT Digital Library
A Comparison of the Linguistic Competence of Learning Disabled and Emotionally Disturbed Pupils (open access)

A Comparison of the Linguistic Competence of Learning Disabled and Emotionally Disturbed Pupils

The problem of this investigation was to compare the linguistic competence of learning disabled and emotionally disturbed pupils by means of two performance tasks. Sixty subjects, seven-and-eight-year old monolingual public and private school pupils, were assigned to three groups of twenty subjects each, learning disabled, emotionally disturbed and normally achieving children. The majority of those in the learning disabled and the normally achieving groups were from middle-class families, with the majority of fathers owners of small businesses. A majority (17) of the emotionally disturbed group attended the public schools.
Date: June 1981
Creator: Hook, Pauline Pepper
System: The UNT Digital Library
An Analysis of the Problem of the Insecurity of Children (open access)

An Analysis of the Problem of the Insecurity of Children

This study is an attempt to find causes and indications of insecurity in elementary school children. Possible solutions and ways to increase security are also explored.
Date: June 1939
Creator: Little, Edith
System: The UNT Digital Library
A Psychological Character Study of Abnormal Escapists as Depicted by Certain Authors (open access)

A Psychological Character Study of Abnormal Escapists as Depicted by Certain Authors

This thesis compares and contrats the abnormal escapism of characters created by Eugene O'Neill, Henrich Ibsen, and Thomas Hardy.
Date: June 1939
Creator: Loy, Mable
System: The UNT Digital Library
Interpersonal Reactions to Bereaved Parents: An Exploration of Attachment and Interpersonal Theories (open access)

Interpersonal Reactions to Bereaved Parents: An Exploration of Attachment and Interpersonal Theories

The experiment examined negative social reactions to bereaved parents from unrelated others. Both the behavior displayed by the parent and attachment style of the perceiver were expected to influence reactions to bereaved parents. Undergraduates at a southern university (N = 239) completed both attachment measures and measures of reactions to videotapes of bereaved parents. Results indicated that bereaved parents do indeed receive negative evaluations from unrelated others, in the form of decreased willingness to interact in various roles. However, a nonbereaved parent displaying depressive symptoms also received negative evaluations. Depressed targets in the present study did receive negative evaluations, supporting the predictions of Coyne's interpersonal-process theory of reactions to depressed individuals. Contrary to the predictions of interpersonal-process theory, a bereaved parent displaying loss content without depressive symptoms also elicited negative evaluations. Coyne's hypothesis that the amount of induced negative affect in the perceiver leads to negative evaluations was not supported by the data. Subjects appear to react to a complex set of factors when forming these evaluations, including both personal and situational information. Two factors may have undermined the present study s ability to adequately test this theory. Subjects may have perceived depressive symptoms in loss content in the present …
Date: June 1990
Creator: Wilhite, Thomas R. (Thomas Ray)
System: The UNT Digital Library
Correlational Study of the UNT Neuropsych-Screen, the MMPI and Time among Chronic Pain Patients (open access)

Correlational Study of the UNT Neuropsych-Screen, the MMPI and Time among Chronic Pain Patients

Although many theorists have speculated that chronic pain may be linked to some sort of central neuropsychological integration deficit, a review of the current literature reveals no empirical support for this theory. This study attempts to assess the severity, if any, of neuropsychological deficits in chronic pain subjects by using a neuropsychological screen developed at the University of North Texas. Also, presented are studies of correlations between the UNT Neuropsych-screen and the MMPI. the Dallas Pain Questionnaire (DPQ), the Dallas Pain Drawing CDPD), and time since injury in order to assess any possible relationships. The subjects in this study consist of 100 volunteers. Of these subjects, 74 were patients of the Spinal and Chronic Pain Center at Medical Arts Hospital in Dallas, Texas and represented the clinical population. The remaining 26 subjects were staff volunteers from the hospital . The results of the study indicate significant differences between chronic pain subjects and non-pain subjects across many areas of neuropsychological functioning, as well as other significant correlations among many of the variables. The implications of this study are elaborated upon, in the discussion section, in detail along with limitations and future research directions.
Date: June 1989
Creator: Smith, Russell Joseph
System: The UNT Digital Library
An Attempt to Produce a High Octane Gasoline from C4 Hydrocarbons (open access)

An Attempt to Produce a High Octane Gasoline from C4 Hydrocarbons

This thesis presents the results of an experiment conducted to discover if selenic acid or monazite sand are possible catalysts that can be used for the alkylation of isobutane and isobutene.
Date: June 1939
Creator: Scott, Howard Winfred
System: The UNT Digital Library
Evaluation of School Units that Affected the Community (open access)

Evaluation of School Units that Affected the Community

This study examines a change from traditional to modern teaching in the Denton, Texas public schools. Issues faced by adminitation and teachers in three examined elementary schools provide information about the implementation of a plan focused on the particular needs of children in the community.
Date: June 1939
Creator: Yarbrough, James Lafayette
System: The UNT Digital Library
An Analysis of the Adequacy of the Health Program in Certain Texas High Schools (open access)

An Analysis of the Adequacy of the Health Program in Certain Texas High Schools

This thesis examines the state of Texas high school health programs using federal standards first established seven years previously.
Date: June 1939
Creator: Heizer, Richmond P.
System: The UNT Digital Library
A Comparative Quantitative Study of the Common Elements Found in the Hackenberry (open access)

A Comparative Quantitative Study of the Common Elements Found in the Hackenberry

This comparative study attempts to determine the importance of soil fertility in determining how much of an element a plant absorbs.
Date: June 1939
Creator: Bailey, Duward W.
System: The UNT Digital Library
A Comparative History of Certain Phases of Early Railway Construction, Financing, and Administration in England, France, Germany, and the United States (open access)

A Comparative History of Certain Phases of Early Railway Construction, Financing, and Administration in England, France, Germany, and the United States

This thesis contrasts railroading history in England, France, Germany, and the United States to highlight the differences and similarities between them.
Date: June 1940
Creator: Fisher, George William
System: The UNT Digital Library
A comparison of the effects of electromyographic biofeedback on muscular tension in selected personality states from the Minnesota multiphasic personality inventory (open access)

A comparison of the effects of electromyographic biofeedback on muscular tension in selected personality states from the Minnesota multiphasic personality inventory

This investigation was concerned with the effects of electromyographic biofeedback on the muscular tension of patients diagnosed in a particular personality state. These personality traits were manic, agitated, depressed, and a comparison group.
Date: June 1978
Creator: Blue, Lisa
System: The UNT Digital Library
CARBON-13 NMR STUDIES OF LIQUID CRYSTALS (open access)

CARBON-13 NMR STUDIES OF LIQUID CRYSTALS

High resolution, proton decoupled {sup 13}C nmr are observed for a series of neat nematic liquid crystals, the p-alkoxyazoxybenzenes, and a smectic-A liquid crystal, diethylazoxydibenzoate in a magnetic field of 23 kG. The (uniaxial) order parameters S = <P{sub 2}(cos{theta})> are found to be about 0.4 and 0.9 for the nematic and smectic-A phase respectively at the clearing points. The order parameter increases with decreasing temperature in the nematic phase but is constant, or nearly so, with temperature in the smectic-A phase. In the nematic series studied, the ordering exhibits an even-odd alternation along the series and qualitative agreement with a recent theory due to Marcelja is found. In both phases, the spectra show that the molecule rotates rapidly about its long axis. Tentative conclusions about molecular conformational motion and {sup 14}N spin relaxation are presented for both nematic and smectic-A phases. In the smectic-A phase, the sample is rotated about an axis perpendicular to H{sub 0} and the resulting spectra are discussed. The theory of observed chemical shifts in liquid crystals is treated in an appendix. Equations are derived which relate the nmr spectra of liquid-crystals to the order parameters. A model for the smectic-C phase due to Luz …
Date: June 1, 1975
Creator: Allison, Stuart
System: The UNT Digital Library