UNT Theses and Dissertations - 18,439 Matching Results

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Effects of Minimum Quantity Lubrication in Drilling 1018 Steel.

Description: A common goal for industrial manufacturers is to create a safer working environment and reduce production costs. One common method to achieve this goal is to drastically reduce cutting fluid use in machining. Recent advances in machining technologies have made it possible to perform machining with minimum-quantity lubrication (MQL). Drilling takes a key position in the realization of MQL machining. In this study the effects of using MQL in drilling AISI 1018 steel with HSS tools using a vegetable based lubricant were investigated. A full factorial experiment was conducted and regression models were generated for both surface finish and hole size. Lower surface roughness and higher tool life were observed in the lowest speed and feed rate combination.
Date: December 2008
Creator: Shaikh, Vasim
Partner: UNT Libraries

Effects of Minimum Quantity Lubrication (Mql) on Tool Life in Drilling Aisi 1018 Steel

Description: It has been reported that minimum quantity lubrication (MQL) provides better tool life compared to flood cooling under some drilling conditions. In this study, I evaluate the performance of uncoated HSS twist drill when machining AISI 1018 steel using a newly developed lubricant designed for MQL (EQO-Kut 718 by QualiChem Inc.). A randomized factorial design was used in the experiment. The results show that a tool life of 1110 holes with a corresponding flank wear of 0.058 mm was realized.
Date: August 2012
Creator: Maru, Tejas
Partner: UNT Libraries

The Effects of Mirror Confrontation on Body Image Ratings

Description: There are conflicting data in the literature regarding the effects of mirror exposure on subjective body-image evaluation. Much of the objective self-awareness research by Duval and Wicklund concluded that the presence of a mirror leads people to evaluate themselves negatively, while other studies have reported contrary findings. The primary purpose of this study was to determine the effects of mirror confrontation on individuals' body image ratings. Subjects were 88 childless, female university students. Using the Eating Disorders Inventory-Body Dissatisfaction subscale (BDS) as a screener, subjects were assigned to either a High Satisfaction group or a Low Satisfaction group. The subjects then completed the Multidimensional Body-Self Relations Questionnaire (MBSRQ) in either a Mirror or No Mirror condition. Results suggest that the presence of the mirror had no measurable effect on the subjects' ratings of themselves on the MBSRQ. There was a main effect for satisfaction level, and no interaction was found between the satisfaction level and the mirror condition. Possible explanations for these findings are offered.
Date: August 1995
Creator: Dell'Era, Maria Elena
Partner: UNT Libraries

The Effects of Missing Data on Audit Inference and an Investigation into the Validity of Accounts Receivable Confirmations as Audit Evidence

Description: The objectives of the thesis research were twofold. One objective was to conduct an exploratory investigation of the underlying response mechanism to an auditor's request for confirmation of accounts receivable. The second objective was to investigate the validity of confirmation evidence. Validity was defined in terms of detection of errors.
Date: August 1987
Creator: Caster, Paul, 1951-
Partner: UNT Libraries

The Effects of Model Prompts on Joint Attention Initiations in Children with Autism

Description: The general purpose of the current study was to evaluate the effects of minimally intrusive prompting procedures and preferred stimuli on protodeclarative joint attention initiations in children diagnosed with autism spectrum disorder (ASD). Two boys and one girl diagnosed with ASD participated. The experimenter provided attention and social interaction following protodeclarative initiations throughout all phases of the study. During intervention, a model prompt was delivered every 30 s if the participant failed to initiate a bid for joint attention. Results for the first participant show that a model prompt was sufficient to increase the rate of protodeclarative initiations across stimulus sets. Generalization was seen across sets, but not across environments. Subsequently, the model prompt was sufficient to increase the rate of protodeclarative initiations across sets in a second setting (classroom). Results for the second participant are inconclusive. Data collected during the initial baseline condition show that she engaged in an incompatible verbal response across sets. When pictorial stimuli depicting highinterest items and activities were introduced, the rate of protodeclarative initiations increased over time. We then returned to original baseline condition and saw an initial decrease, followed by a steady increase in the rate of protodeclarative initiations. The third participant withdrew prematurely due to medical reasons. The findings of the current study show that minimally intrusive prompts and natural consequences may be sufficient to establish protodeclarative initiations in children. However, this finding may be limited to only those children for whom social interactions already function as reinforcers.
Date: December 2014
Creator: James-Kelly, Kimberly L.
Partner: UNT Libraries

The Effects of Modeling, Roleplaying and Feedback on the Performance of Teachers of Children with Autism

Description: Teachers providing treatment to children with autism are responsible for implementing numerous procedures. Teacher training has not been addressed extensively in the literature. This study employed a multiple baseline design to evaluate the effects of a training package incorporating modeling, roleplaying and feedback on teacher performance. Results indicated that the teacher implemented correct teaching episodes following training. Changes in teacher performance were only observed when the training package was applied to each setting and skill area. As a result of changes in teacher behavior, the child demonstrated an increase in the number of desired responses. Results are discussed in the context of generalization, training package components, cost-benefit of single-subject designs, and limitations of the study.
Date: August 1999
Creator: Edwards, Carla Ward
Partner: UNT Libraries

The Effects of Monitoring and Incompatible Contingencies on Say/Do Correspondence.

Description: This study investigated effects of monitoring on correspondence between nonverbal responding and verbal descriptions of those contingencies, when verbal descriptions and contingencies were compatible and when incompatible. In the Nonverbal Component, the contingency for key pressing was either on a 0.8 s IRT or a 3.4 s IRT. In the Verbal Component, subjects made responses to a statement about the contingency for reinforcement in the Nonverbal Component. Shaping was used to establish targets of 0.8 s and 3.4 s in this component. Results indicated that across 7/8 opportunities subjects exhibited nonverbal and verbal behavior that was sensitive to their respective contingencies regardless of compatibility. This sensitivity to contingencies was not affected by the presence of a monitor.
Date: May 2003
Creator: Crye, Amy Arthur
Partner: UNT Libraries

The Effects of Mood State and Intensity on Cognitive Processing Modes

Description: To investigate the effects of emotional arousal on information processing strategy, three different moods (sadness, anger, and happiness) were hypnotically induced at three different levels of intensity (high, medium, and low) in 29 male and female undergraduate students, while engaging them in a visual information processing task. Subjects were screened for hypnotic susceptibility and assigned to either a high susceptibility group or low susceptibility group to account for the attentional bias associated with this trait. All subjects were trained to access the three emotions at the three levels of intensity. During separate experimental sessions, subjects were hypnotized, and asked to access a mood and experience each level of intensity while being administered the Navon Design Discrimination Task, a measure of global and analytic visual information processing. Scores were derived for global processing, analytic processing, and a percentage of global to analytic processing for each level of mood and intensity. Two (hypnotic susceptibility) x 3 (emotion) x 3 (intensity level) repeated measures ANOVAs were computed on the global, analytic, and percentage scores. In addition, two separate ANCOVAs were computed on each dependent measure to account for the effects of handedness, and cognitive style. None of these analyses revealed significant main effects or interactions. The analysis of the percentage scores revealed a trend toward differences between the emotions, but in a direction opposite to that hypothesized. Hypnotic susceptibility does not appear to mediate global and analytic responses to the Navon visual information processing task when emotions are being experienced. Results regarding emotions and emotional intensity were discussed in terms of the problems with adequate control and manipulation of mood and intensity level. Difficulties with the Navon measure were also explored with regard to the exposure duration in the Navon task, and its adequacy in measuring shifts in information processing associated with transient ...
Date: August 1986
Creator: Lamar, Marlys Camille
Partner: UNT Libraries

The Effects of Motivational and Instructional Self Talk on the Attentional Focus of High School Distance Runners.

Description: The purposes of this study were to examine the (a) attentional focus strategies used by high school distance runners, (b) changes in attentional focus across four laps in three 1.6 km runs, and (c) effects of a pre-performance intervention using motivational and instructional self talk on the attentional focus strategies used by and performance of high school distance runners. Participants (N = 42) completed a background and demographic questionnaire, the Cross Country Attentional Focus Inventory (CCAFI), a motivational and instructional statement survey, and the Self-Motivation Inventory. A series of oneway ANOVAs revealed significant differences in the types of attentional strategies used by each group, as well as fluctuations in use of strategies. The experimental group associated more during the each of the 1.6 km trials, whereas the control group dissociated more throughout each trial. A significant group by week interaction was found, with the experimental group maintaining their performance and the control group slowing from week one to week three.
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Date: May 2005
Creator: Burgess, Amber G.
Partner: UNT Libraries

The Effects of Motivational Group Techniques Upon Selected Personality and Behavioral Variables

Description: The problem of this study was to investigate the effects of motivational group techniques upon selected personality and behavioral variables. Particular emphasis was placed upon changes in personality and behavior with respect to freshmen college students.
Date: May 1971
Creator: Ballard, Stanley Newton, 1933-
Partner: UNT Libraries

The Effects of Multicultural College Courses on Intercultural Experiences and Attitudes.

Description: This study examined college undergraduates' intercultural experiences and attitudes at the beginning and the end of a semester-long course on multicultural issues. Participants were 290 undergraduate college students at the University of North Texas , 202 of whom were enrolled in one of the university's core global studies, cross-cultural, or diversity courses for the fall 2001 semester, and 88 of whom were enrolled in courses outside the core. It was hypothesized that the multicultural group's Positive Inventory of the Consequences of Multicultural Experiences scores would increase and Social Dominance Orientation Scale scores would decrease more than they would for the control group. Findings did not support these hypotheses.
Date: December 2004
Creator: Soule, Amy
Partner: UNT Libraries

The Effects of Multisensory Perceptual Training on Reading and Perceptual Development at the First-Grade Level

Description: This was a study designed to investigate the effects of three independent variables in first-grade reading instruction on reading achievement and perceptual development. The independent variables included initial readiness level, type of instructional method, and sex of pupil. The major purpose of this study was to use an experimental setting to determine the relative effects of a multi-sensory perceptual training program combined with a basal-instruction program, as contrasted to an entirely conventional basal-reading program, on first-grade reading achievement and perceptual development during a school year.
Date: 1969
Creator: Nichols, Edith E.
Partner: UNT Libraries

The effects of music and music vibration using the MVT(tm) on the relief of rheumatoid arthritis pain

Description: The pain relieving efficacy of music listening combined with vibrotactile cutaneous stimulation was determined. Music with mechanical vibration (30min. session; average amplitude of 26μm; frequency range of 60-600Hz.) was applied to subjects with rheumatoid arthritis using the Music Vibration Table (MVT). Scores from pain relief visual analogue scales (VAS) and McGill Pain Questionnaires (MPQ) were compared to groups with music alone and placebo.
Date: August 1992
Creator: Chesky, Kris S.
Partner: UNT Libraries

The Effects of Music and Operant Conditioning on Gross Motor Activity of Profound Mental Retardates

Description: It has not yet been demonstrated that music can be used therapeutically with profoundly retarded children. One way these children might be helped to respond to music, and therapeutically benefit from it, would be to use operant conditioning in an effort to enhance gross motor activity and then progressively shape responses until more complex behavior patterns are formed. Once these children can respond motorically in the presence of musical stimuli, continuation of responding may be possible by pairing motor activity with musical stimuli. This experiment investigated the effects of operant conditioning and music on the motor activity of profoundly retarded children in an effort to determine the therapeutic usefulness of music with such children.
Date: January 1968
Creator: Addison, Max R.
Partner: UNT Libraries

Effects of Music on Vividness of Movement Imagery

Description: The purpose of the investigation was to determine the effects of music on self reported vividness of movement imagery. Eighty-four undergraduate kinesiology majors (42 males; 42 females) were subjects. Based on identical perceptions of precategorized music (classical and jazz), selected subjects were randomly assigned to one of three music treatment conditions (sedative, stimulative, and control) and administered the Vividness of Movement Imagery Questionnaire. A 3 x 2 x 2 (Treatment x Gender x Perspective) ANOVA with repeated measures on the last factor was employed. The results revealed that the two music conditions significantly enhanced the vividness of internal and external imagery perspectives when compared to the no music condition, and that music facilitated the vividness of males and females equally.
Date: December 1994
Creator: Tham, Edgar Kok Kuan
Partner: UNT Libraries

The Effects of Music Training on Electroencephalographic Coherence of Preschool Children

Description: The purpose of this study was to examine the effects of music training on electroencephalographic (EEG) coherence of preschool children. EEG coherence is a measurement of brain wave activity that reflects anatomical and neurophysiological parameters and functional connectivity between areas of the brain. Participants were 4- to 6-year-old children divided into two groups: one received music training for 20 minutes twice a week for 10 weeks while the other group served as controls. Nineteen channels of EEG data were collected from each child pre- and post-training. Data were collected from three conditions: eyes-open resting, listening to music, and performing the Object Assembly subtest of the Weschler Preschool and Primary Scale of Intelligence - Revised (1989). The hypothesis was that the music training group would show increased EEG coherence as compared to controls. The EEG data was reduced into seven bandwidths and analyzed separately for each condition. Multiple ANCOVAs were used to factor out pre-test variability and to maximize connectivity changes between the two groups. The dependent measures were the post-QEEG electrode pairs and the covariates were the pre-QEEG electrode pairs. Results indicated the eyes-open and listening to music conditions showed more significant changes between the groups than the Object Assembly condition. Overall, each condition showed increased connectivity for the music training group versus controls. The eyes-open condition differentiated children with and without music training during a resting condition, and showed similar patterns as those identified by other researchers comparing musicians versus nonmusicians. The listening to music condition identified connections including a topographical pattern of auditory analysis, increased working memory activation, increased activity between musically sensitive areas, and increased interhemispheric activity. Findings with the Object Assembly condition were not as robust as expected. However, patterns of increased connectivity associated with visuospatial processing were found with the music training group.
Date: August 1999
Creator: DeBeus, Roger J. (Roger John)
Partner: UNT Libraries

The Effects of Musical Stimuli on the Gross Motor Activity of Profound Mental Retardates

Description: It was the purpose of this present study to investigate the effects of two types of music, tonic and sedative, on the gross motor activity of profound mental retardates. The primary objective was to determine if therapeutic benefits resulting from the application of music could be extended to profound retardates as has already been demonstrated with other levels of retardation.
Date: May 1969
Creator: Angelloz, Robert E.
Partner: UNT Libraries

Effects of n-Decenylsuccinic Acid (n-DSA) and It's Monomethyl Ester (m-MDSA) on Water and Ion Flux in Isolated Roots

Description: The purpose of this study was (1) to measure the changes in water flux in isolated roots exposed to n-DSA and its mono-methly ester (m-MDSA) using a photometric technique in the absence of an externally applied suction and (2) to measure the flux of Na and K in similarly treated roots using a flame photometric method.
Date: January 1969
Creator: Teng, Yao-sheng
Partner: UNT Libraries

Effects of N⁶,O²'-Dibutyryl Cyclic Adenosine 3' ,5' Monophosphate on Transformation of Rat Kidney Cells and Chick Embryo Fibroblasts by Wild-Type and Temperature-Sensitive Rous Sarcoma Virus

Description: N^6,O^2' -Dibutyryl cyclic adenosine 3',5'-monophosphate (Bt_2cAMP) was investigated for its effects on various tissue culture cells infected with temperature-sensitive (ts) mutant, LA31 and Bratislava 77 (B77), a wild-type Rous sarcoma virus. Specifically, known parameters of transformation were investigated and a possible site of action has been tenably proposed. The drug Bt_2cAMP was found to have little effect on the transformation related properties of primary chick embryo fibroblasts (CEF) infected with either virus or normal rat kidney fibroblasts (NRK) infected with the wild-type B77-RSV. However, significant inhibition of the transforming properties in NRK infected with the ts mutant LA31 (LA31-NRK) were reported at the permissive temperature 33 degrees centigrade (33 C).
Date: December 1983
Creator: Marshall, David A. (David Allen)
Partner: UNT Libraries

Effects of Natural/anthropogenic Stressors and a Chemical Contaminant on Pre and Post Mycorrhizal Colonization in Wetland Plants

Description: Arbuscular mycorrhizal fungi, colonizing over 80% of all plants, were long thought absent in wetlands; however, recent studies have shown many wetland plants harbor arbuscular mycorrhizae (AM) and dark septate endophytes (DSE). Wetland services such as biodiversity, shoreline stabilization, water purification, flood control, etc. have been estimated to have a global value of $14.9 trillion. Recognition of these vital services is accompanied by growing concern for their vulnerability and continued loss, which has resulted in an increased need to understand wetland plant communities and mycorrhizal symbiosis. Factors regulating AM and DSE colonization need to be better understood to predict plant community response and ultimately wetland functioning when confronting natural and human induced stressors. This study focused on the effects of water quality, hydrology, sedimentation, and hurricanes on AM and DSE colonization in three wetland species (Taxodium distichum, Panicum hemitomon, and Typhal domingensis) and plant communities of coastal wetlands in Southeast Louisiana and effects of an antimicrobial biocide, triclosan (TCS), on AM (Glomus intraradices) spore germination, hyphal growth, hyphal branching, and colonization in fresh water wetland plants (Eclipta prostrata, Hibiscus laevis, and Sesbania herbacea) from bottom land hardwood forest in north central Texas. The former, mesocosm studies simulating coastal marsh vegetation ran for five years. In the latter studies, AM spores and wetland plants were exposed to 0 g/L, 0.4 g/L, and 4.0 g/L TCS concentrations in static renewal and flow through exposures for 21 and 30 days, respectively. AM and DSE colonization was significantly affected by individual and interactions of four independent variables in mesocosm experiments. Similarly, spore germination, hyphal growth, hyphal branching, and AM colonization in selected wetland plants were significantly lowered by exposure to the TCS at environmentally relevant concentrations. However, levels of effects were plant species and fungal propagules specific. My results showed that natural and human ...
Date: August 2013
Creator: Twanabasu, Bishnu Ram
Partner: UNT Libraries