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Perceptions of Managers in Kuwait on the Role of the Multinational Corporations in Change in Kuwait

Description: The purpose of this study is to investigate the perceptions of managers in Kuwait (both Kuwaiti and non- Kuwaiti) on the effects of multinational corporations (MNCs) in Kuwait and whether these effects were beneficial. The problem motivating this study is the effects that MNCs have on the social, cultural, political, legal, economic, business, and technological environments of their host countries, especially in developing nations. This study is based on a survey of the perceptions of 1,344 managers in Kuwait on the role of MNCs in changes in Kuwait. A review of the literature on MNCs and their relationships with their host countries is provided. This review focuses on four major environmental dimensions (Social-Cultural, Political-Legal, Business-Economic, and Technological) that are affected by MNCs. The factor analysis performed for this study supports this classification of the dimensions in the environment. An English questionnaire was developed from the list of major items in each of these dimensions. An Arabic version was developed using a "double-translation method." Both the English and Arabic versions of the questionnaire were pilot tested. The instrument proved to be reliable and valid. The study utilizes a 2 x 3 block design, categorizing subjects by nationality (Kuwaiti, other Arab, others) and type of organization (public and private). Since most of the variables in the study were measured using nominal and ordinal scales, mostly non-parametric statistics were used for data analysis. The major finding from this study was that managers in Kuwait perceive positive effects of MNCs on change in Kuwait, with the exception of the cultural environment. The favorable perceptions were about the MNCs1 effects on the change in business, economic, and technological environments in Kuwait. The results of the study should be beneficial to the Kuwaiti government, MNCs doing business in Kuwait, and also to cross-cultural researchers interested in …
Date: May 1990
Creator: Al-Daeaj, Hamad S. (Hamad Saleh)
Partner: UNT Libraries
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Personality Characteristics Associated with Pet Ownership: Validating the Theoretical Propositions of Boris Levinson

Description: The purpose of the present study was to provide validation for Levinson's theory about pets and human personality development. Levinson (1978) proposed that the personality development of individuals who have pets to which they are attached differs from that of those who do not have pets and that pets play an important role in facilitating the development of certain adaptive personality traits. In the present study, specific areas that were addressed included differences in certain personality characteristics between life-long pet owners who were strongly attached to their pets, life-long pet owners who were less strongly attached to their pets, and people who had owned pets for only a limited period of time in their lives. One hundred undergraduates completed the Pet Attitude Scale, the Tennessee Self Concept Scale, the Personality Research Form - Form E, the Hogan Empathy Scale, the Fundamental Interpersonal Relations Orientation - Behavior (FIRO-B), and the IPAT Anxiety Scale Questionnaire. No significant differences were found between the three pet owner groups in levels of affiliation with other people, impulse control, nurturance, succorance, capacity for empathy, and anxiety levels. In addition, no significant differences were found between the three pet owner groups in interpersonal behavior characteristics or self-esteem. Concurrent validity was shown between membership in the different pet owner groups and positive attitudes toward pets as measured by the Pet Attitude Scale. As predicted, the most attached life-long pet owners reported more positive attitudes toward pets than the least attached life-long pet owners or the limited-time pet owners.
Date: August 1990
Creator: Esparza, Jana Scoville
Partner: UNT Libraries
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An Examination of Selected Product Characteristics Associated with the Sales Success of Nontheatrical Film and Video Works

Description: The purpose of this study was to test assumptions made about characteristics of nontheatrical film and video works that were thought to contribute to the frequency with which the works were purchased. This study proposed and tested three variables for which relationships to the sales success of nontheatrical film and video works were hypothesized, as well as four variables about which no hypotheses were forwarded. Nineteen film and video distribution organizations contributed unit sales data for the period 1982-1987 on 151 works copyrighted between 1982 and 1984. These data were analyzed for relationships between sales totals and 1) curricular significance of the works' subjects, 2) relevance to general reading interest in the works' subjects, 3) intensity of competition faced by the works, 4) the works' Dewey classifications as compared to the composition of typical K-12 school library book collections, 5) the series or non-series status of the works, 6) the media format(s) in which the works were available for purchase and 7) the sources of the works' production financing. Analyses of correlation and association were performed and no significant relationships were found between sales and curricular significance of the works' subjects, or their relevance to general reading interest. Some evidence was presented to suggest a significant association between the intensity of competition faced by a work and its eventual sales. None of the hypotheses about these variables was supported. However, the four remaining variables were found to be significant, or to approach significance, as correlates or associates of sales success. The best predictor of sales for works intended for the K-12 school market was the work's Dewey Decimal classification. Other important findings included associations between high sales and intense product competition, between high sales and non-series status, between high sales and availability for purchase in 16mm film and between high …
Date: May 1990
Creator: Munde, Gail Marie
Partner: UNT Libraries
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Copland's "Single Vision" and the Piano Sonata: A Lecture Recital, Together with Three Recitals of Selected Works of J.S. Bach, B. Bartok, L.v. Beethoven, F. Chopin, F. Liszt, W.A. Mozart, J.P. Rameau, M. Ravel, and F. Schubert

Description: Difficulties are encountered in any discussion of Copland's style, for his works cover the spectrum from harsh, dissonant works to folk music. To avoid the task of defining a style which encompasses this array of vastly different pieces, a sharp distinction is frequently made between the abstract and popular works. However, Copland has repeatedly objected to such categorization, claiming that he composed from a single vision. A careful examination of his total output proves the validity of his claim. Many common characteristics are found throughout works from all categories and time periods. These traits include a basic economy of materials, emphasis on thirds, consistent method of development, use of declamation, jazz-influenced rhythms, cyclicism, and a slow/fast/slow sequence of movements, as well as within single movements. This document uses the Piano Sonata as a model of Copland's style, for it exemplifies these characteristics more clearly than any other major piece for piano. By making numerous comparisons with other works, Copland's single vision is revealed.
Date: August 1990
Creator: Morris, Gregory W. (Gregory Wayne)
Partner: UNT Libraries
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Parent Adaptive Doll Play with Children Experiencing Parental Separation/Divorce

Description: Parent Adaptive Doll Play, a technique in an early stage of development, is designed for use by parents in assisting their young children to cope with the stresses of parental separation/divorce. The effects of technique implementation by parents of three- through six-year-old children were investigated. Data was collected before and after parents received training and implemented the technique over an eight-week period. Parents completed the Child Behavior Rating Scale, Burks' Behavior Rating Scales, the Parenting Stress Index, and the Parental Attitude Scale. Twenty-two parents, reporting marital separation through separation and/or divorce, within 18 months prior to the beginning of the study, and reporting more than 50 percent physical custody of a three- through six-year-old child qualified for participation. Twelve children were experimental subjects and ten were control subjects. To determine differences between groups, a one-way analysis of covariance was performed on each post test variable. Positive differences were calculated in several areas of child behavior by parents of subjects in the experimental group. No significant differences between groups were found in any area of child behavior. The score which most closely approached significance, however, was found in the Burks' Behavior Rating Scale area of poor anger control.
Date: December 1990
Creator: Brennan, Carol A. (Carol Ann)
Partner: UNT Libraries
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A State-Wide Survey on the Utilization of Instructional Technology by Public School Districts in Texas

Description: Effective utilization of instructional technology can provide a valuable method for the delivery of a school program, and enable a teacher to individualize according to student needs. Implementation of such a program is costly and requires careful planning and adequate staff development for school personnel. This study examined the degree of commitment by Texas school districts to the use of the latest technologies in their efforts to revolutionize education. Quantitative data were collected by using a survey that included five informational areas: (1) school district background, (2) funding for budget, (3) staff, (4) technology hardware, and (5) staff development. The study included 137 school districts representing the 5 University Interscholastic League (UIL) classifications (A through AAAAA). The survey was mailed to the school superintendents requesting that the persons most familiar with instructional technology be responsible for completing the questionnaires. Analysis of data examined the relationship between UIL classification and the amount of money expended on instructional technology. Correlation coefficients were determined between teachers receiving training in the use of technology and total personnel assigned to technology positions. Coefficients were calculated between a district providing a plan fortechnology and employment of a coordinator for instructional technology. Significance was established at the .05 level. A significant relationship was determined between the total district budget and the amount of money allocated to instructional technology. There was a significant relationship between the number of teachers receiving training in technology and the number of personnel assigned to technology positions. A significant negative relationship was determined between the district having a long-range plan for technology and the employment of a full-time coordinator for one of the subgroups. An attempt was made to provide information concerning the effort by local school districts to provide technology for instructional purposes. Progress has been made, although additional funds will be …
Date: May 1990
Creator: Hiett, Elmer D. (Elmer Donald)
Partner: UNT Libraries
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The Professional Contributions of Ruth I. Anderson to Business Education

Description: This study explored the professional contributions of Ruth I. Anderson, retired professor of Business Administration, The University of North Texas, Denton, Texas. The data for this study were gained through questionnaire responses, a telephone interview, and personal interviews with faculty, staff, students, and business people who have worked closely with Anderson and an interview with Anderson herself. During a literature review, many of the journal articles written by Anderson were read in order to obtain insight into the thoughts and ideas Anderson had toward business education. The dissertation, divided into six chapters, begins with an introduction to the study. Chapter 1 includes the statement of the problem, purposes of the study, research questions, significance of the study, rationale for the study, and design of the study. Chapter 2 contains a biographical sketch of Ruth Anderson and offers a chronology of her career in business education. Anderson's educational philosophy is the focus of Chapter 3. Chapter 4 addresses her major accomplishments and contributions to business education. Anderson's impact on business education is the topic of Chapter 5. A summary is provided in Chapter 6. This study recognized Ruth Anderson as a significant person in the field of business education. Anderson, who was employed in the field for more than forty years, is the author, or co-author, of six books and the contributor of more than eighty articles published in professional journals. Major educational contributions of Ruth Anderson included publications, research, and involvement in professional organizations at the local, state, and national levels. Anderson made an impact on the field of business education through being a role model for former students, being a well-respected colleague, and being well known in the business education profession. Perhaps her greatest gift to the profession was her superior classroom teaching ability. Ruth Anderson's greatest contribution continues …
Date: May 1990
Creator: Matthews, Barbara G. (Barbara Gayle)
Partner: UNT Libraries
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Selected Vocal Exercises and Their Relationship to Specific Laryngeal Conditions: a Description of Seven Case Studies

Description: Good vocal health is a vital concern for those people who use the voice in a professional capacity, such as teachers, singers, actors, clergymen, and lawyers. Research in the area of vocal health reveals the need to determine if specific exercises are beneficial to the voice and if exercises used to train the singing voice might be beneficial to alleviate pathological and/or dysfunctional voice disorders. The purpose of this study was to describe the response of a variety of pathological voices to a selected set of singing exercises. Subjects were selected from the private practice of cooperating physicians who felt that the vocal instruction and exercise program might be helpful to the teachers, students, professional "pop" singers, and housewife-singers who were diagnosed to have muscle tension dysphonia, nodules, recurrent laryngeal nerve paralysis, or iatrogenic dysphonia. Instrumentation for assessing conditions before, during, and after exercise included a brief case history, subject interviews, attending physicians' medical charts, flexible fiberoptic video nasolaryngoscopy, video cassette recorder and video tape segments, three physician/observers, and a specific diagnostic procedure which provided a method of assessing organic, functional, and perceptual variables. For the exercise program the researcher chose seven vocalises from the routine designed by Allan R. Lindquest, whose techniques combined those of the Italian school with those of Swedish studios which produced such singers as Flagstad and Bjoerling. The seven vocalises included a warm up "massage" and exercises for separation and blending of the registers, vowel clarity and modification, tone focus, vocal attack, and flexibility. Since all the subjects showed improvement after exercise in the vocal conditions observed in this study, these vocalises and technique may be helpful to alleviate pathological conditions and/or dysfunctional behavior in other subjects. The researcher further suggests that the voice profession investigate the efficiency of other techniques, exercises, and musical vocalises …
Date: May 1990
Creator: Mathis, Barbara
Partner: UNT Libraries
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Criteria by Which Ad Hoc Labor Arbitrators are Selected by Union and Management Advocates in the Petroleum Refining Industry

Description: A non-experimental, descriptive study was conducted to examine the criteria by which ad hoc labor arbitrators are selected in the petroleum refining industry. Three factors — arbitrator background, recognition, and arbitration practice — were examined to determine their relative importance to advocates selecting ad hoc labor arbitrators. The population of the study consisted of management and labor union advocates in the petroleum refining industry who routinely select ad hoc labor arbitrators. Participating management and union advocates completed a questionnaire used to gather respondents' evaluations of criteria considered in the selection of ad hoc arbitrators. Responses to statements designed for measuring relative importance of the criteria considered were recorded. Descriptive statistics, discriminant analysis, and tests of significance were used in the treatment of the data.
Date: August 1990
Creator: Wayland, Robert F. (Robert Franklin)
Partner: UNT Libraries
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An Ethnographic Study of the Use of Puppetry with a Children's Group

Description: This study utilized an ethnographic methodology to examine and describe the various aspects and processes occurring in a children's group as the members created their own puppets and accompanying puppet plays. Individual and interactive behavior patterns were isolated and analyzed as a means of gaining an in depth understanding of the puppetry process. The puppetry process, in turn, was viewed in terms of information it provided regarding the individual members and the group process. The facilitative and non-facilitative aspects of the procedure were delineated. The adult leader met with a group of six boys, in grades four and five, for 12 one-hour sessions in which they made puppets and then created puppet plays around issues that they had articulated as problems. The group sessions were videotaped and transcribed. The transcriptions were coded in an effort to extensively analyze the puppetry process and the group process, and the ways in which the two processes interacted. An independent observer/rater was utilized in order to provide some validity for the researcher's reported results. The puppet-making task appeared to offer an opportunity for individuals to begin to come together in a common, but individual task. Characteristic styles and individual personality dynamics were evidenced. General response to the task was enthusiastic, with varying degrees of satisfaction expressed regarding their finished products. The play-creating and performing process met with less success than the puppet-making. While the group members appeared to be generally amenable to contributing ideas for the puppet plays, the process met with far more resistance in the cooperative task of putting their ideas into a finished product. The group discussion and interaction that occurred around these tasks provided a vehicle by which to view levels of interpersonal skills and the group's overall stage of development. The puppets the children created appeared to act as …
Date: August 1990
Creator: Deniger, Marcy M. (Marcy Marble)
Partner: UNT Libraries
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Development of an Expert System to Teach Diagnostic Skills

Description: The primary purpose of the study was to develop an expert system that could C D perform medical diagnoses In selected problem areas, and C2) provide diagnostic Insights to assist medical students In their training. An expert system Is a computer-based set of procedures and algorithms that can solve problems In a given domain. Two research questions were proposed. The first was "Given a problem space defined by a matrix of diseases and symptoms, can a computer-based model be derived that will consistently perform accurate and efficient diagnoses of cases within that problem area?" The second question was "If the techniques derived from the model are taught to a medical student, is there a subsequent improvement of diagnostic skill?" An expert system was developed which met the objectives of the study. It was able to diagnose cases in the two problem areas studied with an accuracy of 94-95%. Furthermore, it was able to perform those diagnoses in a very efficient manner, often using no more than the theoretical minimum number of steps. The expert system employed three phases: rapid search by discrimination, confirmation by pattern matching against prototypes, and elimination of some candidates (impossible states) by making use of negative information. The discrimination phase alone achieved accuracies of 73-78%. By comparison, medical students achieved mean accuracies of 54-55% in the same problem areas. This suggests that novices could improve their diagnostic accuracy by approximately 20% by following the simple rules used in the first phase of the expert system. Curricular implications are discussed. When 49 first-year medical students at the Texas College of Osteopathic Medicine were exposed to some of the insights of the expert system by means of a videotaped 10- minute lecture, their diagnostic approach was modified and the accuracy of their diagnoses did improve. However, the degree …
Date: August 1990
Creator: Elieson, S. Willard (Sanfred Willard)
Partner: UNT Libraries
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Observation by flow sup 1 H NMR and dimerization kinetics and products of reactive ortho-quinodimethanes and benzocyclobutadiene

Description: The reactive o-quinodimethanes, 1,2-dimethylene-1,2-dihydronaphthalene (9) and o-xylylene (1) were observed by flow {sup 1}H NMR spectroscopy at room temperature. The {sup 1}H NMR spectrum of 9 was obtained in the absence of precursor and dimers. However, the {sup 1}H NMR spectrum of the more reactive 1, generated in a similar manner from (o-((trimethylsilyl)methyl)benzyl)trimethylammonium iodide (5.) could be obtained only in the presence of its stable (4 + 2) and (4 + 4) dimers. The dimerization kinetics of 3-methyl- (5{prime}), 3,6-dimethyl- (11), 3-isopropyl- (12), and 3,6-diisoproply-1,2-xylylene (13) in acetonitrile (CH{sub 3}CN) were studied by stopped-flow UV-visible spectroscopy. Fluoride ion induced 1,2-elimination from 2-elimination from 2-trimethylsilylbenzocyclobutenyl-1 mesylate (26) was used to generate the reactive molecule benzocyclobutadiene (1{prime}) in CD{sub 3}CN, which was observed by flow {sup 1}H NMR spectroscopy at room temperature. The {sup 1}H NMR spectrum (in CD{sub 3}CN) of 1,2-dimethylene-1,2-dihydrothiophene (1{double prime}), obtained by fluoride ion induced 1,4-elimination from 3-(trimethylammoniummethyl)-2-(trimethylsilylmethyl)thiophene iodine was observed by flow {sup 1}H NMR spectroscopy at room temperature. The dimerization rate of 1{double prime} in CH{sub 3}CN, generated in the same manner, was measured by UV-visible spectroscopy. 166 refs., 7 figs., 7 tabs.
Date: September 21, 1990
Creator: Fischer, David
Partner: UNT Libraries Government Documents Department
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Magnetic and thermal properties of high Tc superconductors

Description: Measurements of the normal state magnetic susceptibility {chi}(T) of YBa{sub 2}Cu{sub 3}O{sub 7}, Bi{sub 1.8}Pb{sub 0.2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}}, and Bi{sub 2{minus}x}Pb{sub x}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub 10+{delta}} (x = 0.2 and 0.25) were carried out. All {chi}(T) data show negative curvature below {approximately}2{Tc}. The data for YBa{sub 2}Cu{sub 3}O{sub 7} are in excellent agreement with a new calculation of the superconducting fluctuation diamagnetism. From the analysis, we infer s-wave pairing and microscopic parameters are obtained. For {chi}(T) of YBa{sub 2}Cu{sub 3}O{sub 7}, part of the negative curvature is inferred to arise from the normal state background. We find a strong temperature dependent anisotropy {delta}{chi} {equivalent to} {chi}{sub c} {minus} {chi}{sub ab} and estimate the normal state spin contributions to {chi}(T). The heat capacity C(T) of YBa{sub 2}Cu{sub 3}O{sub 7} is reported for 0.4 K < T < 400 K in zero and 70 kG magnetic fields. In addition to the feature associated with the onset of the superconductivity at {Tc}, two anomalies in C(T) were observed near 74 K and 330 K, with another possible anomaly near 102 K; the temperatures at which they occur correlate with anomalies in {chi}(T) and ultransonic measurements. The occurrence of the anomaly at {approx equal} 330 K is found to be sample-dependent. The influences of a magnetic field and the thermal and/or magnetic field treatment history dependence of a pellet sample on C(T), the entropy and the influence of superconducting fluctuations on C(T) near {Tc}, and the possible source of the observed intrinsic nonzero {gamma}(0) at low T are discussed.
Date: September 21, 1990
Creator: Lee, Wonchoon
Partner: UNT Libraries Government Documents Department
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A Search for Thermal Isomerization of Olefins to Carbenes: Thermal Generations of the Silicon-Nitrogen Double Bond

Description: The first part of this thesis will search for the thermal isomerization of olefins to carbenes which is predicted to be a high energy process by calculations and has only been observed in a few strained olefins. The possibility of thermal isomerization of simple olefins to carbenes will be explored. Substitution of a silyl group on the double bond of an olefin allows a potential intermediate which has a {beta}-radical to the silyl group during the cis-trans isomerization. The effects of a trimethylsilyl group on this isomerization are the subject of this study. The second part of this thesis will include the generation and chemistry of intermediates containing a silicon-nitrogen double bond. The isomerization of parent silanimine to the aminosilylene was calculated to be a high energy process. New approaches to the silicon-nitrogen double bond will also be presented. 92 refs., 12 figs., 11 tabs.
Date: September 21, 1990
Creator: Zhang, Xianping
Partner: UNT Libraries Government Documents Department
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Physical metallurgy and magnetic behavior of Cd stabilized bcc (beta)Gd alloys

Description: As a continuation of the research on bcc Gd-Mg alloy system by Herchenroeder and Gschneidner, the metastable bcc Gd-Cd alloys were studied with the emphasis on their metallurgical and magnetic properties. An essentially single phase alloy could be retained for Cd concentrations from 15 at. % Cd to 19 at. % Cd, which is in the vicinity of the eutectoid composition of {beta}Gd in the Gd-Cd system. The lattice constants obtained for these alloys were used to determine the lattice constant of pure bcc Gd by extrapolation to 0 at. % Cd. Good agreement between this extrapolated value and that obtained from Gd-Mg alloys by using the same method suggested the validity of such extrapolation method. Thermal stability of these metastable bcc Gd-Cd alloys was examined by using differential thermal analysis (DTA).
Date: September 21, 1990
Creator: Tang. Jinke
Partner: UNT Libraries Government Documents Department
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A reciprocal space approach for locating symmetry elements in Patterson superposition maps

Description: A method for determining the location and possible existence of symmetry elements in Patterson superposition maps has been developed. A comparison of the original superposition map and a superposition map operated on by the symmetry element gives possible translations to the location of the symmetry element. A reciprocal space approach using structure factor-like quantities obtained from the Fourier transform of the superposition function is then used to determine the best'' location of the symmetry element. Constraints based upon the space group requirements are also used as a check on the locations. The locations of the symmetry elements are used to modify the Fourier transform coefficients of the superposition function to give an approximation of the structure factors, which are then refined using the EG relation. The analysis of several compounds using this method is presented. Reciprocal space techniques for locating multiple images in the superposition function are also presented, along with methods to remove the effect of multiple images in the Fourier transform coefficients of the superposition map. In addition, crystallographic studies of the extended chain structure of (NHC{sub 5}H{sub 5})SbI{sub 4} and of the twinning method of the orthorhombic form of the high-{Tc} superconductor YBa{sub 2}Cu{sub 3}O{sub 7-x} are presented. 54 refs.
Date: September 21, 1990
Creator: Hendrixson, Ton
Partner: UNT Libraries Government Documents Department
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Optical properties and electronic structures of d- and f-electron metals and alloys, Ag-In, Ni-Cu, AuGa sub 2 , PtGa sub 2 ,. beta. prime -NiAl,. beta. prime -CoAl, CeSn sub 3 , and LaSn sub 3

Description: Optical properties and electronic structures of disordered Ag{sub 1- x}In{sub x}(x = 0.0, 0.04, 0.08, 0.12) and Ni{sub 1-x}Cu{sub x} (x = 0.0, 0.1, 0.3, 0.4) alloys and ordered AuGa{sub 2}, PtGa{sub 2}, {beta}{prime}-NiAl, {beta}{prime}-CoAl, CeSn{sub 3}, and LaSn{sub 3} have been studied. The complex dielectric functions have been determined for Ag{sub 1-x}In{sub x}, Ni{sub 1-x}Cu{sub x}, AuGa{sub 2}, and PtGa{sub 2} in the 1.2--5.5 eV region and for CeSn{sub 3} and LaSn{sub 3} in the 1.5--4.5 eV region using spectroscopic ellipsometry. Self-consistent relativistic band calculations using the linearized-augmented-plane-wave method have been performed for AuGa{sub 2}, PtGa{sub 2}, {beta}{prime}-NiAl, {beta}{prime}-CoAl, CeSn{sub 3}, and LaSn{sub 3} to interpret the experimental optical spectra.
Date: October 17, 1990
Creator: Kim, Kwang Joo
Partner: UNT Libraries Government Documents Department
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Electrical Resistivity of Some Zintl Phase and the Precursors

Description: Resistivity measurements have been performed for electric characterization of the compounds Ba{sub 5}Sb{sub 3} and Ba{sub 5}Sb{sub 3}Cl, both with the Mn{sub 5}Si{sub 3} structure type, along with Ca{sub 5}Bi{sub 3} and Ca{sub 5}Bi{sub 3}F, both with the {beta}-Yb{sub 5}Sb{sub 3} structure type. These measurements were taken as a function of temperature using the four probe method on pressed polycrystalline pellets of the compounds. A sealed apparatus was developed for containing these air-sensitive compounds throughout the experiments. By a simple electron count, one extra electron in both Ba{sub 5}Sb{sub 3} and Ca{sub 5}Bi{sub 3} should occupy a conduction band, giving these compounds a metallic character. In the cases of Ba{sub 5}Sb{sub 3}Cl and Ca{sub 5}Bi{sub 3}F, the extra electron should bond to the halide, both filling the valence band and giving rise to semiconducting character. Ca{sub 5}Bi{sub 3}, Ca{sub 5}Bi{sub 3}F, and Ba{sub 5}Sb{sub 3}Cl were found to comply with the electron count prediction. Ba{sub 5}Sb{sub 3}, however, was found to be a semiconductor (E{sub g} = 0.30 eV) with a larger band gap than its corresponding chloride (E{sub g} = 0.09 eV).
Date: September 21, 1990
Creator: Wolfe, Larry
Partner: UNT Libraries Government Documents Department
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High-resolution angle-resolved photoemission studies of high Tc superconductor Bi sub 2 Sr sub 2 CaCu sub 2 O sub 8

Description: An angle-resolved photoemission study of the normal and superconducting states in Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8} was performed. Measurements in the normal state show bands dispersing through the Fermi level from at least 350 meV below E{sub F}. The Fermi level crossings are consistant with local-density band calculation, including a point calculated to be of Bi-O character. Additional measurements were made where bands crossed the Fermi level between 100 and 250K, along with measurements on an adjacent Pt foil. The Fermi edges of both materials agree to within the noise. Below the Fermi level, the spectra show correlation effects on the form of an increased effective mass. The shape of the spectra can be explained by a lifetime-broadened photohole and secondary electrons. The effective inverse photohole lifetime is linear in energy. A superconducting gap has been measured at a number of points where there is density at the Fermi level in the normal state. By proper modeling, a gap of 24 meV was obtained for all these points, including points of Cu-O and Bi-O character respectively, according to band calculation. The lack of gap anisotropy in the basal plane suggests that pinning in this material is not d-wave pairing.
Date: September 21, 1990
Creator: Liu, Rong
Partner: UNT Libraries Government Documents Department
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Reactions of the excited state of polypyridyl chromium(III) ion

Description: There has been much recent interest in the photochemistry and photophysics of transition metal polypyridine complexes due to the possibility of their use in solar energy conversion systems. The excited state of these compounds are known to undergo useful electron transfer and energy transfer reactions. This work attempts to elucidate the mechanism of the quenching of *CrL{sub 3}{sup 3+} (where L = 2,2{prime}-bipyridine, 4,4{prime}-dimethyl-2,2{prime}-bipyridine, 1,10-phenanthroline, 5-chloro-1,10-phenanthroline, 5-methyl-1,10-phenanthroline) by oxalate ions in neutral pH. Evidence suggests an ion-pairing pre-equilibrium followed by rate limiting electron transfer to produce CrL{sub 3}{sup 2+} and CO{sub 2}{sup {minus}} can then react with ground state chromium(III) species to produce another mole of the reduced product or it can produce a secondary transient as in the case of phenanthroline and substituted phenanthroline complexes. The secondary transient reacts to produce CrL{sub 3}{sup 2+} in a subsequent reaction. 85 refs., 24 figs., 7 tabs.
Date: September 21, 1990
Creator: Steffan, Carl
Partner: UNT Libraries Government Documents Department
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Fundamental Investigations of Supported Monometallic and Bimetallic Catalysts by Proton Magnetic Resonance Spectroscopy

Description: Proton magnetic resonance spectroscopy, or nuclear magnetic resonance (NMR) of hydrogen, has been applied to investigate silica-supported Group VIII monometallic and Group VIII-Group IB bimetallic catalysts and alumina- and silica-supported platinum-rhenium bimetallic catalysts. Two adsorbed states of hydrogen, i.e., irreversible and reversible hydrogen, on the surfaces of monometallic Ru, Pt, and Cu particles and bimetallic Ru-Group Ib, Pt-Group Ib, and Pt-Re particles were observed directly via proton NMR. The same amounts of the irreversible hydrogen adsorbed on pure Ru catalysts were measured by both proton NMR and the volumetric technique. The electronic environments on surfaces of monometallic catalysts are sensitive to changes in metal dispersion, state of adsorbed hydrogen, and residual chlorine. Surface compositions for the Ru--Cu and Pt--Cu bimetallic catalysts were determined by NMR of adsorbed hydrogen. 297 refs., 96 figs., 19 tabs.
Date: September 21, 1990
Creator: Wu, Xi
Partner: UNT Libraries Government Documents Department
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Electrocatalysis of Anodic and Cathodic Oxygen-Transfer Reactions

Description: The electrocatalysis of oxygen-transfer reactions is discussed in two parts. In Part I, the reduction of iodate (IO{sub 3}{sup {minus}}) is examined as an example of cathodic oxygen transfer. On oxide-covered Pt electrodes (PtO), a large cathodic current is observed in the presence of IO{sub 3}{sup {minus}} to coincide with the reduction of PtO. The total cathodic charge exceeds the amount required for reduction of PtO and IO{sub 3}{sup {minus}} to produce an adsorbed product. An electrocatalytic link between reduction of IO{sub 3}{sup {minus}} and reduction of PtO is indicated. In addition, on oxide-free Pt electrodes, the reduction of IO{sub 3}{sup {minus}} is determined to be sensitive to surface treatment. The electrocatalytic oxidation of CN{sup {minus}} is presented as an example of anodic oxygen transfer in Part II. The voltametric response of CN{sup {minus}} is virtually nonexistent at PbO{sub 2} electrodes. The response is significantly improved by doping PbO{sub 2} with Cu. Cyanide is also oxidized effectively at CuO-film electrodes. Copper is concluded to serve as an adsorption site for CN{sup {minus}}. It is proposed that an oxygen tunneling mechanism comparable to electron tunneling does not occur at the electrode-solution interface. The adsorption of CN{sup {minus}} is therefore considered to be a necessary prerequisite for oxygen transfer. 201 refs., 23 figs., 2 tabs.
Date: September 21, 1990
Creator: Wels, Brian R.
Partner: UNT Libraries Government Documents Department
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Diffusion of trichloroethylene through the threaded joints of PVC (polyvinylchloride) pipe

Description: The data engineers and scientists use to determine if the groundwater supply is contaminated are derived from analysis of samples taken largely from monitoring wells. For these data to be reliable several factors must be considered. One factor is the integrity of the monitoring well. In this project, emphasis has been placed on the potential impact on water quality caused by diffusion across the threaded joints of PVC pipe. In this study, the diffusion of trichloroethylene across several common types of threaded joints (i.e., square flush, modified ACME, modified ACME stub, and ACME) has been measured. Samples were obtained from the water inside the pipe sections and analyzed for trichloroethylene by gas chromatography. Breakthrough occurs within days of the samples being placed in the baths. The softened PVC joints of the pipes in the pure trichloroethylene split before the first sample interval of 1.5 weeks. The data show great variability in casting joints from the same manufacturer, and indicate a need for increased precision in the manufacturing of the PVC pipe joints. A one-dimensional diffusion model is used to determine an equivalent gap size through which the diffusion occurs. Flow rates through the threaded joints are calculated by using the equivalent gap width and a formula for flow through a rectangular duct running full. Comparison of the results of the gap size calculations and of the flow rates is presented. 20 refs., 13 figs. 11 tabs.
Date: December 1, 1990
Creator: Jerome, Karen M.
Partner: UNT Libraries Government Documents Department
open access

Exclusive neutral strange particle production from double Pomeron exchange produced by proton-proton interactions at radical s = 62 GeV

Description: Data are presented for the first time on exclusive Pomeron-Pomeron interactions which produce a neutral strange and neutral antistrange particle pair in a central system X. In this paper, the system, X, is identified as one of the following neutral combinations; K{sub s}{sup 0}K{sub s}{sup 0}, K{sub s}{sup 0}K{sup {plus minus}}{pi}{sup {minus plus}}, {Lambda}{sup 0}{bar {Lambda}}{sup 0}, {Lambda}{sup 0}{bar {Lambda}}{sup 0}*. These data were obtained in proton-proton collisions at {radical}s = 62 GeV at the CERN ISR. The triggering systems used to obtain these data are described, followed by a description of the data. The central system mass distributions are presented along with differential mass cross section estimates. A broad enhancement is seen in the K{sub s}{sup 0}K{sub s}{sup 0} system at a mass of 1.2 GeV, and is likely to have the quantum numbers J{sup PC} = 0{sup ++}. Total cross section estimates of 1.3 {plus minus} .64 {mu}b in the K{sub 2}{sup 0}K{sub s}{sup 0} system, . 44 {plus minus} .14 {mu}b in the K{sub s}{sup 0}K{sup {plus minus}}{pi}{sup {minus plus}} system, .20 {plus minus} .14 {mu}b in the {Lambda}{sup 0}{bar {Lambda}}{sup 0} system, and .13 {plus minus} .06 {mu}b in the {Lambda}{sup 0}{bar {Lambda}}{sup 0}* system are obtained.
Date: September 21, 1990
Creator: Skeens, John
Partner: UNT Libraries Government Documents Department
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