225 Matching Results

Search Results

Advanced search parameters have been applied.

Investigation of boiling burnout and flow stability for water flowing in tubes

Description: Report presenting measurements of boiling-burnout heat-transfer rates with water flowing vertically upward in electrically heated tubes. Flow stability in the test section during burnout was affected by the amount of pressure drop across a throttling valve located upstream. A compressible volume introduced in the flow system between the throttling valve and the test section resulting in unsteady flow during burnout.
Date: September 1958
Creator: Lowdermilk, Warren H.; Lanzo, Chester D. & Siegel, Byron L.
Partner: UNT Libraries Government Documents Department

Some Measurements of Boiling Burn-Out

Description: Report presenting measurements of boiling burn-out heat flux for water flowing upward through an electrically heated tube for ranges of velocity, pressure, length-diameter ratios, and subcooling.
Date: February 23, 1955
Creator: Lowdermilk, Warren H. & Weiland, Walter F.
Partner: UNT Libraries Government Documents Department

Predicting Burnout In High-school Journalism Teachers: An Exploratory Study

Description: This research investigated high-school journalism educators’ use and teaching of convergence technology, as well as their self-efficacy, job satisfaction, job dissatisfaction, and burnout. In general, instructions and uses of multimedia tools were not as prevalent as traditional-journalism instructions and tools. One-third of the teachers expressed moderate or strong levels of burnout in terms of their emotional exhaustion. Although both job satisfaction and job dissatisfaction were strong predictors of burnout, self-efficacy was not. Job dissatisfaction was the strongest predictor of burnout, but contrary to the past research, gender turned out to be the second strongest predictor. Qualitative in-depth interviews with a controlled random sampling of survey respondents revealed that maternal mindset and gender roles strongly contribute to female high-school journalism teachers’ expressed burnout and emotional exhaustion.
Date: December 2011
Creator: Sparling, Gretchen B.
Partner: UNT Libraries

Understanding Principal Perceptions of Stress and Burnout: A Qualitative Case Study in North Texas School Districts

Description: This qualitative case study examined principals' perceptions regarding stress and burnout, investigated perspectives regarding ways to alleviate chronic stress, and analyzed the extent to which future role expectations are related to chronic stress and feelings of burnout. Perceptions of eight elementary principals in large, suburban school districts who experienced similar professional preparation prior to receiving their first principalship were analyzed. Participants, identified through criterion sampling, completed a demographic survey and then participated in a one-on-one interview with the researcher. Once data were collected, interviews were transcribed and analyzed to determine categories and themes. Findings revealed that participants struggle with significant stress in six specified domains: school type, students, parents and community, staff, district personnel, and other. Half of participants perceive that their stress will rise during the next five to ten years. Thirty-eight percent predicted that job stress will decline in the coming years, though they do not believe that identified stress factors will decrease. Instead, they believe that factors such as experience will help them to deal more effectively with the same challenges. Furthermore, 63% of participants do not plan to remain in their current principalship until retirement. All participants reported current personal stress-management strategies that fall into the categories of work-home balance or healthy habits. In campus-specific strategies, 63% focused on staff morale-building opportunities. Finally, 38% of participants did not feel that their district provides strategies that assist in the management of principalship stress.
Date: August 2016
Creator: Lovell, Joy E
Partner: UNT Libraries


Description: Recent studies of heterogeneous reburning, i.e., reburning involving a coal-derived char, have elucidated its variables, kinetics and mechanisms that are valuable to the development of a highly efficient reburning process. Young lignite chars contain catalysts that not only reduce NO, but they also reduce HCN that is an important intermediate that recycles to NO in the burnout zone. Gaseous CO scavenges the surface oxides that are formed during NO reduction, regenerating the active sites on the char surface. Based on this mechanistic information, cost-effective mixed fuels containing these multiple features has been designed and tested in a simulated reburning apparatus. Remarkably high reduction of NO and HCN has been observed and it is anticipated that mixed fuel will remove 85% of NO in a three-stage reburning process.
Date: January 14, 2005
Creator: Chen, Wei-Yin & Gathitu, Benson B.
Partner: UNT Libraries Government Documents Department

Heterogeneous Reburning By Mixed Fuels

Description: Recent studies of heterogeneous reburning, i.e., reburning involving a coal-derived char, have elucidated its variables, kinetics and mechanisms that are valuable to the development of a highly efficient reburning process. Young lignite chars contain catalysts that not only reduce NO, but they also reduce HCN that is an important intermediate that recycles to NO in the burnout zone. Gaseous CO scavenges the surface oxides that are formed during NO reduction, regenerating the active sites on the char surface. Based on this mechanistic information, cost-effective mixed fuels containing these multiple features has been designed and tested in a simulated reburning apparatus. Remarkably high reduction of NO and HCN has been observed and it is anticipated that mixed fuel will remove 85% of NO in a three-stage reburning process.
Date: March 31, 2009
Creator: Hall, Anderson
Partner: UNT Libraries Government Documents Department

A Meta-Analysis of Burnout and Occupational Stress

Description: The relationship between occupational stress and burnout was investigated through a meta-analysis of 81 studies and 364 correlations. Occupational stress was measured by role conflict, role ambiguity, workload, cumulative role stress, job specific stress/stressors, and work setting characteristics. Burnout was measured by the Maslach Burnout Inventory, 1981 and 1986 versions, emotional exhaustion, depersonalization, and reduced personal accomplishment components of burnout, measures of tedium, and the Staff Burnout Scale for Health Professionals. Thirty occupations in human and non-human service organizations throughout four publication periods were examined. Results indicated occupational stress strongly predicts burnout in non-human service organizations like industry and manufacturing as well as the human services. Job specific stressors most strongly predict burnout across organization types and occupation. Occupational stress predicts emotional exhaustion and depersonalization more than perceptions of reduced personal accomplishment. The findings support the use of transactional models of stress which consider occupational context as a precipitator of burnout, especially emotional exhaustion.
Date: August 1999
Creator: Collins, Vivian A.
Partner: UNT Libraries


Description: A general non-uniform burnup program was developed to determine the lifetime of the APPR-1. The calculation is performed using two one dimensional multi-region burnout calculations. The approach to the problem, the equations, and derivation of burnout equations are presented. The results are plotted and compared with the rod bank position as measured at Fort Belvoir. On the basis of these calculations the expected total energy release of the APR-1 is 13 Mw-yr. (auth)
Date: April 10, 1958
Creator: Williamson, T. G.
Partner: UNT Libraries Government Documents Department

Effects of a Self-care Intervention for Counselors on Compassion Fatigue and Compassion Satisfaction

Description: This study investigated the impact of a psychoeducational and experiential structured counselor self-care curriculum, developed by Drs. Charles and Kathleen Figley, on compassion fatigue and the prevention of professional impairment as measured by the Professional Quality of Life (ProQOL), Version 5. Volunteer licensed professional counselors, supervisors, and interns from four children's advocacy centers in Texas were assigned to treatment group (n = 21; 20 females, 1 male; mean age 34.4 years) or waitlist control group (n = 21; 19 females, 2 males; mean age 34.6 years). Participating counselors identified themselves ethnically as 64% Caucasian, 26% Hispanic, 7% African-American, and 2% Native-American. Employing a quasi-experimental design, three reliability-corrected analysis of covariance (ANCOVA) were utilized to analyze the data with an alpha level of .05 to assess statistical significance and partial eta squared to assess effect size. With pre-test scores as the covariate, results revealed in the experimental group a statistically significant reduction with large treatment effect for burnout (p = .01; partial ?2 = .15), a statistically nonsignificant reduction with a medium effect for secondary traumatic stress (p = .18; partial ?2 = .05), and a statistically nonsignificant increase with a medium effect for compassion satisfaction (p = .06; partial ?2= .09). Findings supported the use of this curriculum to train counselors on self-care as required of professional counselors by the American Counseling Association code of ethics and listed as a necessary skill in the standards of the Council for Accreditation of Counseling and Related Educational Programs.
Date: December 2012
Creator: Koehler, Christine Marie Guthrie
Partner: UNT Libraries

The Association between Sense of Humor, Coping Ability and Burnout among Nursing Education Faculty

Description: A nonexperimental descriptive study was conducted to determine the interrelatedness among coping strategies, humor and burnout among nursing education faculty. The conceptual framework of this study was based on the constructs of coping strategies and humor which were conceptualized as having a direct relationship to burnout. Areview of the literature concerning coping, humor and burnout supported this proposition and emphasized the need for empirical testing. Coping Humor Scale. Wavs of Coping Questionnaire and Maslach Burnout Inventory were the instruments used to measure the constructs. Academic history and demographic data sheets were also used. Hie instruments were mailed to 285 nursing faculty teaching in programs of nursing in the Dallas /Fort Worth, Texas area. The return rate for the mailing was 70.07%. Burnout among nursing education faculty showed a low degree of emotional exhaustion (54.8%), a low degree of depersonalization (84.7% and a low degree of personal accomplishment (60.7%). The findings did not reveal a high or low degree of burnout but rather a pattern of burnout suggestive of a different stage. Humor as a coping mechanism during stressful events was not frequently used. The highest proportion of nursing education faculty used distancing (46.53%) as a coping strategy. The second strategy used was planful problem solving (11.3%) with escape-avoidance used the least (3.34%). Multiple regression was used to test the research questions related to the predictor variables of coping, academic history and demographic data as they relate to each criterion variable of burnout. The use coping strategies (including humor) to predict various stages of burnout revealed only weak variable predictors. Academic history and demographic were also weak predictors for burnout.
Date: May 1996
Creator: Talbot, Laura A. (Laura Ann)
Partner: UNT Libraries

Relationship Between Coaches' Leadership Style and Burnout

Description: The purpose of the present study was to examine the relationship between leadership behavior and perceived burnout of coaches. Head coaches from high schools and from Southeast and Southwest Conference universities were included in the sample (N=302). Coaches completed the Maslach Burnout Inventory (MBI), Leader Behavior Description Questionnaire, Social Desirability Scale and a demographic data sheet. Coaches were separated into two leadership behavior groups and classified as Consideration or as Initiating Structure. It was predicted that coaches in the Consideration Group would have a higher level of perceived burnout. A multivariate analysis of variance was conducted and indicated significant differences in four subscales of the MBI. Specifically, coaches in the Consideration Group scored significantly higher in the frequency and intensity dimension of the emotional exhaustion and depersonalization subscales (p<.001).
Date: August 1987
Creator: Dale, Judith A. (Judith Anne)
Partner: UNT Libraries

Personality Correlates of Burnout in Teachers

Description: Career burnout has been recognized as a syndrome marked by mental, physical and emotional exhaustion which is especially prevalent among teachers. Teacher burnout is currently a widely researched phenomenon and controversy over its definition, causes and interventions has been great. Meanwhile, the burnout construct has gained little clarity. The purpose of the present study was to determine whether identifiable personality characteristics, as measured by the Personality Research Form, were consistently associated with burnout in teachers, as measured by the Maslach Burnout Inventory and the Cognitive Burnout Scale. Moderately strong relationships were found between specific personality characeristics and reported levels of burnout. However, individual factors were not concluded to be as critical as the interaction between such factors and the environment. Future directions are discussed.
Date: December 1986
Creator: Nash, Leslie Tennant
Partner: UNT Libraries

Graphite burnout, interim report on IP-25-A (PT-105-532-E)

Description: Graphite reacts with such gases as CO{sub 2}, O{sub 2}, or water vapor to form gaseous oxides of carbon. In the case of CO{sub 2}-graphite interaction, the reaction rate is not significant until about 550 C. Water oxidizes graphite, very roughly, three times faster than CO{sub 2}. Air will oxidize graphite appreciably at temperatures below 500 C. Graphite removal from Hanford reactors is very important, since graphite is used both as a structural support and a moderator for neutrons. Griggs has shown that small graphite samples oxidized to 10 per cent weight loss had only about one-half their original compression strength. Hence, the longevity of the reactors depends to a great extent on maintaining a low graphite oxidation rate. A means of monitoring the extent of graphite loss, i. e., the burnout rate, is necessary to establish future reactor operational standards. Presently, weighed samples of reactor grade graphite are placed along the length of an empty process channel in each reactor. Thus, a sample is exposed to the reactor`s ambient conditions of power level, moderator temperature, and gas composition. This program was initiated in the vicinity of June, 1953 by Woodley. This report presents data on graphite burnout obtained from in-reactor experiments authorized under IP-25-A (PT-105-532-E) from August, 1957 to January, 1960. Burnout rates are obtained by a direct measurement of the weight loss of control graphite samples exposed to the reactor atmosphere.
Date: March 15, 1960
Creator: Ryan, B.A. & Halas, D.R. de
Partner: UNT Libraries Government Documents Department

Droplet entrainment correlation for high pressure annular two-phase flow

Description: The amount of entrainment in annular flow is essential to predict the point of dryout. Most of the entrainment correlations available in the literature are obtained from air-water low pressure data. However many important industrial applications involve high pressure annular flows. There are very few correlations applicable in this range and they are solely based on empirical data fits. Comparing the low pressure entrainment data of Cousins and Hewitt (1968) and the high pressure data of Keeys et. al. (1970) and Wurtz (1978) with existing correlations, the agreement at high pressure is generally poor, except for the empirical correlation of Nigmatulin and Krushenok (1989) which depends on a Weber number that includes the droplet concentration. We propose a new semi-mechanistic entrainment correlation for fully developed annular flow conditions: E = (0.9642)/(1 + (3836/We{sub C})). It is developed based on the droplet continuity equation and the entrainment rate model of Dallman et. al. (1979). This model is then modified to introduce a Weber number that includes the droplet concentration, We{sub C}. This Weber number is shown to scale the available high and low pressure air-water and steam-water data better than the other definitions. Because the new correlation is based on a model of entrainment rate it may be used as a starting point in the development of a correlation for this process applicable to high pressure water-steam annular flows. A correlation is suggested pending validation with high pressure entrainment rate data. 12 refs., 11 figs.
Date: January 1, 1996
Creator: Lopez de Betodano, M.A.; Jan, Cheng-Shiun & Beus, S.G.
Partner: UNT Libraries Government Documents Department

Kinetics of fly ash beneficiation by carbon burnout: Quarterly report, October 1-December 31, 1997

Description: To investigate the kinetics of beneficiation of fly ash by carbon burnout The project is a joint venture between Delmarva Power, a power generating company on the eastern shore of Maryland, and the University of Maryland Eastern Shore. The studies have focused on the beneficiation of fly ash by carbon burnout.
Date: December 31, 1997
Partner: UNT Libraries Government Documents Department

Experimental time to burnout of a prototypical ITER divertor plate during a simulated loss of flow accident

Description: Under the sponsorship of the Department of Energy, Office of Utility Technologies, the Energy Storage System Analysis and Development Department at Sandia National Laboratories (SNL) conducted a cost analysis of energy storage systems for electric utility applications. The scope of the study included the analysis of costs for existing and planned battery, SMES, and flywheel energy storage systems. The analysis also identified the potential for cost reduction of key components.
Date: February 1, 1997
Creator: Marshall, T.D.; Watson, R.D. & McDonald, J.M.
Partner: UNT Libraries Government Documents Department

An investigation of late-combustion soot burnout in a DI diesel engine using simultaneous planar imaging of soot and OH radical

Description: Diesel engine design continues to be driven by the need to improve performance while at the same time achieving further reductions in emissions. The development of new designs to accomplish these goals requires an understanding of how the emissions are produced in the engine. Laser-imaging diagnostics are uniquely capable of providing this information, and the understanding of diesel combustion and emissions formation has been advanced considerably in recent years by their application. However, previous studies have generally focused on the early and middle stages of diesel combustion. These previous laser-imaging studies do provide important insight into the soot formation and oxidation processes during the main combustion event. They indicate that prior to the end of injection, soot formation is initiated by fuel-rich premixed combustion (equivalence ratio &gt; 4) near the upstream limit of the luminous portion of the reacting fuel jet. The soot is then oxidized at the diffusion flame around the periphery of the luminous plume. Under typical diesel engine conditions, the diffusion flame does not burn the remaining fuel and soot as rapidly as it is supplied, resulting in an expanding region of rich combustion products and soot. This is evident in natural emission images by the increasing size of the luminous soot cloud prior to the end of injection. Hence, the amount of soot in the combustion chamber typically increases until shortly after the end of fuel injection, at which time the main soot formation period ends and the burnout phase begins. Sampling valve and two-color pyrometry data indicate that the vast majority (more than 90%) of the soot formed is oxidized before combustion ends; however, it is generally thought that a small fraction of this soot from the main combustion zones is not consumed and is the source of tail pipe soot emissions.
Date: October 1, 1999
Creator: Dec, John E. & Kelly-Zion, Peter L.
Partner: UNT Libraries Government Documents Department

Uncertainties Affecting BOSFN for the Mark 15 Assembly

Description: Technical and transient protection limits are specified on the nominal burnout safety factor, BOSFN, to avoid significant release of fission products caused by local film boiling burnout. The risk of fission product release, BOR, due to film boiling burnout is statistically determined where allowances are made to account for differences between the nominal assembly and the actual assembly. This report describes the calculational model behind BOR and how the specific numerical values were estimated. The data listed in this report enable damage calculations with COBAD to be performed for the Mark 15 assembly.
Date: August 9, 2001
Creator: Hamm, L.L.
Partner: UNT Libraries Government Documents Department

Upflow Burnout Data for Water at 2000, 1200, 800, and 600 Psia in Vertical 0.070 In. X 2.25 In. X 72 In. Long Stainless Steel Rectangular Channels, Corrections

Description: Upflow burnout data for water at 2000, 1200, 800, and 600 psia in vertical 0.070 in. by 2.25 in. by 72 in. long stainless steel rectangular channels are presented. The burnout heat fluxes for these channels depend upon the same parameters as did previously tested channels with much smaller L/D ratios. Bettis burnout design equations were used in calculations. (J.R.D.)
Date: July 1, 1958
Creator: Troy, N.
Partner: UNT Libraries Government Documents Department


Description: A description of the nuclear and thermal analysis involved in the design of the WCAP-4 in-pile test is presented. Calculations reveal that no burn-out conditions are expected at the operating fluxes. Calculations of central core temperature and heat output are included. Various hot spot factor calculations for both non-local and local boiling conditions are also given. (J.R.D)
Date: January 1, 1960
Creator: Bourina, A.; Eich, W. & Lombardo, J.J.
Partner: UNT Libraries Government Documents Department

Thermal-Hydraulic Bases for the Safety Limits and Limiting Safety System Settings for HFIR Operation at 100 MW and 468 psig Primary Pressure, Using Specially Selected Fuel Elements

Description: This report summarizes thermal hydraulic analyses performed to support HFIR operation at 100 MW and 468 psig pressure using specially selected fuel elements. The analyses were performed with the HFIR steady state heat transfer code, originally developed during HFIR design. This report addresses the increased core heat removal capability which can be achieved in fuel elements having coolant channel thicknesses that exceed the minimum requirements of the HFIR fuel fabrication specifications. Specific requirements for the minimum value of effective uniform as-built coolant channel thickness are established for fuel elements to be used at 100 MW. The burnout correlation currently used in the steady-state heat transfer code was also compared with more recent experimental results for stability of high-velocity flow in narrow heated channels, and the burnout correlation was found to be conservative with respect to flow stability at typical HFIR hot channel exit conditions at full power.
Date: September 1, 1998
Creator: Rothrock, R.B.
Partner: UNT Libraries Government Documents Department


Description: This project is designed to develop a family of novel NO{sub x} control technologies, called Second Generation Advanced Reburning which has the potential to achieve 90+ NO{sub x} control in coal fired boilers at a significantly lower cost than Selective Catalytic Reduction. The sixth reporting period in Phase II (January 1-March 31, 1999) included experimental activities and combined chemistry-mixing modeling on advanced gas reburning. The goal of combustion tests was to continue the work on identifying prospective promoters for the advanced reburning process. Tests were conducted in Controlled Temperature Tower (CTT) and Boiler Simulator Facility (BSF). Tests showed that some promoters significantly affect the reburning process when co-injected with NH{sub 3} . The promoters injected into reburning zone without NH{sub 3} in the amount 30 ppm do not significantly affect the reburning process. The modeling effort was focused on the description of Na effect on CO emissions in advanced reburning. Increase in CO concentration in flue gas upon Na injection results from inhibition of CO oxidation by Na species in the burnout zone.
Date: April 29, 1999
Creator: Maly, Peter M.; Lissianski, Vitali V. & Zamansky, Vladimir M.
Partner: UNT Libraries Government Documents Department


Description: SRI has completed the NBFZ test program, made modification to the experimental furnace for the HPBO test. The NBFZ datasets provide the information NEA needs to simulate the combustion and fuel-N conversion with detailed chemical reaction mechanisms. BU has determined a linear swell of 1.55 corresponding to a volumetric increase of a factor of 3.7 and a decrease in char density by the same factor. These results are highly significant, and indicate significantly faster burnout at elevated pressure due to the low char density and large diameter.
Date: January 28, 2003
Creator: Chris Guenther, Ph.D.
Partner: UNT Libraries Government Documents Department