Two continuous performance tests were administered to normal adult subjects. The mode of presentation (visual or auditory) and the type of task (vigilance or distractibility) were varied, and their effects on performance measured. Data were collected on eighty-two subjects, and results indicated that auditory presentation of stimuli increased the difficulty of both tasks. Results also suggest that the distractibility task administered in either mode was more difficult than the vigilance task. Intercorrelations among the four continuous performance tasks are provided. Normative data are presented on all four tasks administered. A measure of symptoms of attention-deficit disorder in adults, the Adult Behavior Checklist, was found to correlate significantly with another measure of pathology, the SCL-90-R.

Although it is widely assumed that listening is among the most important learning skills (Wolvin & Coakley, 1988), an examination of the literature indicates that it has been woefully neglected as subject matter in schools. Listening has also been neglected as an area of research. Surveys have been conducted to see if listening is being taught or can effectively be taught, but little evidence exists to suggest that effectively teaching listening improves students' academic performance. This study investigated the relationship between listening skills instruction and academic performance among university students. The purpose was to determine if teaching university students comprehensive listening skills improves their academic performance. It was assumed that listening can be effectively taught. The goal of the study was to compare 75 students who were enrolled in a listening course to a similar group of 75 students not enrolled in a listening course. The students were compared on the basis of grade point improvement the semester after the experimental group had completed the listening course. The t test was chosen because it can be used for testing the significance of the difference between the means of two independent samples. The grade point averages of the two groups were …

The present study used the Psychoanalytic Rorschach Profile (PRP) to assess differences in personality organization in violent and nonviolent juvenile offenders.

This dissertation deals with the decision-to-move process of elderly persons—from a marketer's perspective. The central problem addressed is the lack of empirical knowledge concerning the factors and influences associated with the information search process of elderly persons in making a residential move decision. The purpose was to investigate and understand the key factors and influences which are viewed as important by elderly individuals in their search for and use of information.

The purpose of the present study was to examine cognitive abilities and problem solving processes of young and older adults. Specifically, three areas of inquiry were investigated: possible age-related differences in problem solving cognitive abilities, possible differences in cognitive processes used during problem solution, and possible differences in determinants of problem solving cognitive processes.

This dissertation analyzes the political leadership crisis and the violations of human rights in the Arab countries during the period 1970 to 1990. The main purposes of this study could be briefly summarized as follows: (1) to explore scientifically whether there is a political leadership crisis in the Arab World; (2) to explore the concept of political leadership, i.e., what constitutes political leadership, what are its necessary requirements, and what differentiates it from dictatorship; and (3) to examine the effects of political leadership in the Arab countries upon the violation of human rights.

In this study, the unique style of percussion writing in the chamber works of George Crumb, written between 1960 and 1980, is examined. The principal aspects examined within this study include: the extended instrumental techniques, the use of percussion within the musical imagery, soloistic treatment, compositional and notational procedures, and specific performance problems pertaining to the chamber work Songs, Drones, and Refrains of Death.

Information system (IS) support of human problem solving during the complex task of auditing within a computer environment was investigated. 74 computer audit specialist professionals from nine firms participated in the field experiment. Task accomplishment behavior was recorded via a computerized activity-logging technique. Theoretical constructs of interest included: 1) IS problem-solving support, 2) task domain knowledge, and 3) decision-making behavior. It was theorized that task domain knowledge influences the type of IS most functionally appropriate for usage by that individual. IS task presentation served as the treatment variable. Task domain knowledge was investigated as a moderating factor of task accomplishment Task accomplishment, the dependent variable, was defined as search control strategy and quality of task performance. A subject's task domain knowledge was assessed over seven theoretical domains. Subjects were assigned to higher or lower task domain knowledge groups based on performance on professional competency examination questions. Research hypothesis one investigated the effects of task domain knowledge on task accomplishment behavior. Several task domain knowledge bases were found to influence both search control strategy and task performance. Task presentation ordering effects, hypothesis two, were not found to significantly influence search control strategy or task performance. The third hypothesis investigated interaction effects …

A double modulation microwave spectrometer is used to evaluate the linewidth parameters for some excited rotational components in the bending vibration v_8 of 13CH3 13C 15N and 13CH3C15N isotopomers of methyl cyanide. The linewidth parameters for self-broadening of the ΔJ=2←1 rotational components for the ground v_8 , 1v_8, and the 2v_8 vibrations were determined over a pressure range of 1 to 13 mtorr and at a temperature of 300 K. The double modulation technique is used to explore the high eighth derivative of the line shape profile of the spectral line. This technique proved to give good signal-to-noise ratios and enabled the recovery of weak signals. An experimental method is developed to correct for source modulation broadening. The tests of the ratios of the two inner peak's separation of the eighth derivative of the line showed that they were up to 95% similar to those for a Lorentzian line shape function. The line shapes were assumed to be Lorentzian for the theoretical analysis of the derivative profiles and comparisons were made between experiment and theory on this basis. Dipole moments for vibrationally excited states were calculated from linewidth parameters and show systematic decrease with the increase of excitation. Impact parameters …

America has adopted as its own the Eden myth, which has provided the mythology of the American dream. This New Garden of America, consequently, has been a masculine garden because of its dependence on the myth of the Fall. Implied in the American dream is the idea of a garden without Eve, or at least without Eve's sin, traditionally associated with sexuality. Our canonical literature has reflected these attitudes of devaluing feminine power or making it a negative force: The Scarlet Letter, Moby-Dick, Adventures of Huckleberry Finn, The Great Gatsby, and The Sound and the Fury. To recreate the Garden myth, Americans have had to reimagine Eve as the idealized virgin, earth mother and life-giver, or as Adam's loyal helpmeet, the silent figurehead. But Eve resists her new roles: Hester Prynne embellishes her scarlet letter and does not leave Boston; the feminine forces in Moby-Dick defeat the monomaniacal masculinity of Ahab; Miss Watson, the Widow Douglas, and Aunt Sally's threat of civilization chase Huck off to the territory despite the beckoning of the feminine river; Daisy retreats unscathed into her "white palace" after Gatsby's death; and Caddy tours Europe on the arm of a Nazi officer long after Quentin's suicide, …

Radioactive metal waste makes up a significant portion of the waste currently being sent for disposal. Recovery of this metal as a valuable resource is possible through the use of decontamination technologies. Through the development and use of expert systems a comparison can be made of laser decontamination, a technology currently under development at Ames Laboratory, with currently available decontamination technologies for applicability to the types of metal waste being generated and the effectiveness of these versus simply disposing of the waste. These technologies can be technically and economically evaluated by the use of expert systems techniques to provide a waste management decision making tool that generates, given an identified metal waste, waste management recommendations. The user enters waste characteristic information as input and the system then recommends decontamination technologies, determines residual contamination levels and possible waste management strategies, carries out a cost analysis and then ranks, according to cost, the possibilities for management of the waste. The expert system was developed using information from literature and personnel experienced in the use of decontamination technologies and requires validation by human experts and assignment of confidence factors to the knowledge represented within.

The purpose of the present cross-sectional study was to examine the effects of ambiguity of loss and type of caregiver-to-patient relationship on anticipatory grief, negative physical and psychological outcomes associated with grief, and boundary ambiguity in family caregivers of chronically ill patients. Questionnaires were completed by 23 parents of ill children and 30 spouses of ill mates. Using an original and a revised concept for level of ambiguity, partial support was found for the prediction that parents and spouses in high ambiguity of loss circumstances would report more anticipatory grief than those in low ambiguity ones. Contrary to prediction, a slight but nonsignificant trend occurred for parents and spouses in low ambiguity situations to report more negative physical and psychological effects associated with grief as well. Level of ambiguity was not found to impact boundary ambiguity as had been hypothesized. Spouses reported more boundary ambiguity than parents, regardless of level of ambiguity of the loss. Contrary to prediction that parents would report less anticipatory grief and more negative physical and psychological outcomes than spouses, generally, no significant differences were found between the two groups. However, using the original concept of ambiguity, parents did tend to recall more past grief than …

The literature does not clearly describe the potential moral and ethical conflicts that can exist between technology sponsors and the technical communicators whose job it is to present potentially risky technology to the non-technical people most likely to be imperiled by such risk. Equally important, the literature does not address the issue of uncertainty -- not the uncertainty likely to be experienced by the community at risk, but the unreliable processes and methodologies used by technology sponsors to define, quantify, and develop strategies to mitigate technological risks. In this paper, the author goes beyond a description of risk communication, the nature of the generally predictable interaction between technology advocates and non-technically trained individuals, and current trends in the field. Although that kind of information is critical to the success of any risk communication activity, and he has included it when necessary to provide background and perspective, without knowing how and why risk assessment is done, it has limited practical applicability outside the sterile, value-free vacuum in which it is usually framed. Technical communicators, particularly those responsible for communicating potential technological risk, must also understand the social, political, economic, statistical, and ethical issues they will invariably encounter.

Despite the apparent simplicity of controlled fusion, there are many phenomena which have prevented its achievement. One phenomenon is laser-plasma instabilities. An investigation of one such instability, stimulated Brillouin scattering (SBS), is reported here. SBS is a parametric process whereby an electromagnetic wave (the parent wave) decays into another electromagnetic wave and an ion acoustic wave (the daughter waves). SBS impedes controlled fusion since it can scatter much or all of the incident laser light, resulting in poor drive symmetry and inefficient laser-plasma coupling. It is widely believed that SBS becomes convectively unstable--that is, it grows as it traverses the plasma. Though it has yet to be definitively tested, convective theory is often invoked to explain experimental observations, even when one or more of the theory`s assumptions are violated. In contrast, the experiments reported here not only obeyed the assumptions of the theory, but were also conducted in plasmas with peak densities well below quarter-critical density. This prevented other competing or coexisting phenomena from occurring, thereby providing clearly interpretable results. These are the first SBS experiments that were designed to be both a clear test of linear convective theory and pertinent to controlled fusion research. A crucial part of this …

A chemical synthesis route is discussed which results in a low- temperature precursor to Y-Ba-Cu-O ceramics; it is based on use of molten Ba(OH){sub 2}{center_dot}8H{sub 2}O flux. Two different chemical systems have been examined; the first one, based on nitrate salts, has been demonstrated to be a viable precursor material for tape casting and extrusion; the second, made from acetate salts, has been used for powder synthesis and extrusion. Rheology of pastes shows that their flow may be fit to either Bingham Plastic or Hershel- Bulkley models. Yield stress is controlled in both pastes by volume fraction solids. Viscosity also follows solids loading in the paste. Shear thinning is controlled by colloidal nature of precursor. The paste has colloidal microstructure. Comparison of concentric cylinder rheometry and piston extrusion rheometry shows order of magnitude differences in yield stress, resulting from the test method and paste dilation.

In this study, 78 kindergarten and first-grade children were interviewed about their writing to identify indicators of self-assessment. Writing samples for each participant were saved over a three month period, then compared and discussed by the child. Results indicated that these young children did engage in self:-assessment behaviors. The classroom teachers were asked to place the participants in their classes along a writing continuum known as a Writing Band. Graphs were presented to show the writing levels of the children by classroom. In addition, each classroom was surveyed to document events which promote literacy development within the framework of an integrated curriculum. Writing samples for each child were collected and kept in a portfolio. Participants were interviewed regarding the contents of the portfolio. Children in two of the kindergarten classes were interviewed using 5 samples collected over a 2 1/2 month time period, and all other participants were interviewed using 6 writing samples collected over a 3 month period. Findings indicated that not only did these young children recognize growth in their writing, but they also assessed that growth based on outward, physical features of their writing. The writing ability of each child at the beginning of the study did …

Collective Thomson scattering from ion-acoustic waves at 266nm is used to obtain spatially resolved, two-dimensional electron density, sound speed, and radial drift profiles of a collisional laser plasma. An ultraviolet diagnostic wavelength minimizes the complicating effects of inverse bremsstrahlung and refractive turning in the coronal region of interest, where the electron densities approach n{sub c}/10. Laser plasmas of this type are important because they model some of the aspects of the plasmas found in high-gain laser-fusion pellets irradiated by long pulse widths where the laser light is absorbed mostly in the corona. The experimental results and LASNEX simulations agree within a percent standard deviation of 40% for the electron density and 50% for the sound speed and radial drift velocity. Thus it is shown that the hydrodynamics equations with classical coefficients and the numerical approximations in LASNEX are valid models of laser-heated, highly collisional plasmas. The versatility of Thomson scattering is expanded upon by extending existing theory with a Fokker-Planck based model to include plasmas that are characterized by (0 {le} k{sub ia}{lambda}{sub ii} {le} {infinity}) and ZT{sub e}/T{sub i}, where k{sub ia} is the ion- acoustic wave number, {lambda}{sub ii} is the ion-ion mean free path, Z is the …

This study was designed to ascertain whether group achievement test data can determine special education referral accuracy. One hundred eighty-nine special education referrals from four school districts in Texas were examined. The demographics were limited to group achievement test data: grade equivalents and percentiles in the subject areas of reading, spelling, language arts, and mathematics. Also examined were referral and eligibility outcomes to special education.

The purpose of the study was to compare the relative benefits of treating at-risk students, those considered to be potential dropouts, by separating them into special classes at a separate facility—a pullout program—versus having them remain in regular classes with periodic supplemental counseling based upon individual needs—a mainstream program. To carry out the purpose of the study, students enrolled in the two types of treatment programs were compared in respect to retention in school, attendance, academic achievement based upon pretest and posttest scores, report card grades, and attitude toward school.

The continuous recrystallization (CRX) appears to be fundamental in Al-Sc because it occurs irrespective of solute composition. It appears to be due to a combination of subgrain coalescence at low strains and incorporation of additional dislocations generated during grain boundary sliding at higher strains when the misorientation has increased sufficiently. Alloying additives such as Mg, Li are more important with respect to deformation after CRX is completed. Mg, and to a lesser extent Li, affect the max m-values (strain-rate sensitivities) in Al-Sc by changing the melting points (mp). Max m- values correlate inversely with mp so that the alloy with the greatest Mg had the highest m-values and lowest mp; the stress is raised at which power-law creep and breakdown occurs. The power-law breakdonw at much lower stresses in Al-0.5Sc and Al-1.2Li-0.5Sc causes the m-value to decrease more rapidly with strain rate. Al alloys for commercial superplastic applications should contain elements that raise the power-law strength so that the m-values are maximized while preserving the post-formed mechanical properties. Refs, figs, tabs.

In this study, the author examined the effect of grazing on phosphorus cycling in stream periphyton and leaf detritus communities using the snail Elimia clavaeformis. Phosphorus cycling fluxes and turnover rates were measured in a laboratory and in a natural stream, respectively, using radioactive tracer techniques.

The primary purpose of this study was to determine if book reviews are useful and significant indicators of potential circulation. Major book reviewing sources were studied to determine if some were more useful than others in selecting books which circulate.

The determination of carbon monoxide is also possible by trapping CO on preconditioned molecular sieve and thermal desorption. Analysis in this case is performed by gas chromatography/mass spectroscopy, although the trapping technique is applicable to other suitable GC techniques.

The study was undertaken: (a) to categorize the contents of educational computing articles using a taxonomy developed by Knezek, Rachlin, and Scannell (1988), (b) to examine the trends in educational computing subject matter addressed in community/junior college journals between 1977 and 1991, and (c) to identify and analyze specific characteristics of contributing authors and their employing institutions which might explain writing and publication biases.