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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Room radiation dose coefficients for external exposure

Finklea, Lauren 21 September 2015 (has links)
In instances where a building room is radiologically contaminated, dose rate coefficients are needed to estimate the dose rate to the occupants. One’s position in the room, whether in the center of the room or the corner, could have an effect on dose rate. The Environmental Protection Agency (EPA) published in Federal Guidance Report 12 (EPA 1993) dose rate coefficients for idealized exposure geometries, including exposure to radionuclides distributed infinitely in various thicknesses of soil. The dimensions of the exposure plane were taken to be infinite in extent. Due to this assumption, using the Federal Guidance Report coefficients could lead to an incorrect estimate of dose rate inside a contaminated room. In order to apply the published coefficients for a structure, we developed Room Ratios using MCNP5 to compare air kerma rate of various room sizes and multiple building materials to the published infinite air kerma rate taking into account several receptor positions. Room Ratio values will be used for preliminary remediation risk assessment for environmental radionuclide clean up and be integrated into existing online tools and databases (epa-bprg.ornl.gov). The incorporation of ratios into these tools will update dose coefficients that previously accounted only for surface contamination (Eckerman 2010). Additionally, Room Ratios will allow Federal Guidance Report 12 dose coefficients application to customizable building materials and thickness.
12

Enhancing exposure therapy for specific phobias using a pre-treatment fear priming task

York, Jamie Lauren 07 November 2014 (has links)
Recent animal and human research suggest that a behavioral prime before extinction training lessens the spontaneous recovery of learned fear. These findings would have large ranging implications, if they could be applied to the treatment of specific phobias in which spontaneous recovery is often problematic. The present study examined the effects of a behavioral prime paired with exposure therapy versus exposure therapy alone on snake and spider phobics return of fear at one-month follow-up. The findings did not support the proposed hypothesis that those in the primed group would show a significant lessening in return of fear. The study findings do not support the current research, but there are a number of steps that may be taken in the future to gain more objective measurements that may lead to hypothesis support. / text
13

Numerical modelling of masonry compartment walls in fire situations

O'Gara, Martin January 2000 (has links)
No description available.
14

Underwater hearing thresholds and hearing mechanisms

Al-Masri, Mohammad Ahmad Oqlah January 1993 (has links)
No description available.
15

Exposure assessment of urban transport users to particulate air pollution

Adams, Helen Sarah January 2001 (has links)
No description available.
16

Investigations into the neurochemical aberrations associated with lead exposure

McIntosh, M. J. January 1986 (has links)
No description available.
17

The rationale of regulation of environmental pollutants : role of expert committees

Krstic, Goran January 1994 (has links)
No description available.
18

A Schoolwide Tiered Intervention for Increasing Fruit and Vegetable Consumption

Mendoza, Blanca L. 12 1900 (has links)
Childhood obesity rates in the U.S. are increasing. Increasing intake of fruits and vegetables is one method to combat obesity. The purpose of this study was to examine a tiered approach to fruit and vegetable consumption with 26 children in an inclusive preschool. The first tier included ongoing availability and opportunity to eat fruits and vegetables (exposure). The second tier included programmed consequences (a reward system). A multiple baseline across children and classrooms was used to evaluate the effect of the interventions. The tier one intervention was effective for nine children and tier two was effective for six children. Eleven children, however, did not respond to either condition. Results are discussed in the context of previous research and tertiary interventions.
19

Maladaptive and Protective Parenting Behaviors in the Context of Exposure for Youth with Social Anxiety Disorder

Norris, Lesley Anne January 2014 (has links)
Thesis advisor: Karen Rosen / Thesis advisor: Nancy Lau / Prior research has demonstrated that parental control, parental criticism, and parental acceptance are associated with social anxiety in youth (Wood, McLeod, Sigman, Hwang, & Chu 2003). However, researchers have not examined how these parenting behaviors might impact youth treatment responses. Research in this area has also relied almost exclusively on self and child- report measures. The current study used a newly developed behavioral observation coding system to observe: (1) parental control; (2) parental criticism; (3) quality of parent-child interaction (parental acceptance); (4) parental monitoring of youth anxiety; and (5) discussion of emotion in the context of a public speaking exposure therapy for socially anxious youth (n=39) ages 8-16 years (M = 10.82, SD = 1.94). It was hypothesized that (1) parents of socially anxious youth would exhibit higher levels of parental control, parental negativity, and parental monitoring of youth anxiety, (2) that the quality of interaction would be lower in socially anxious parent-child dyads, and (3) that parents of socially anxious youth would be less likely to discuss emotions with their children. Results demonstrated that parents of socially anxious youth offered significantly more praise than parents of non-socially anxious youth, (F(1, 33) = 5.662, p = 0.023). Parents of socially anxious youth also offered higher levels of directive help (F(1, 33) = 3.713, p = 0.063), although this finding was only trending towards significance. Potential explanations for these findings are discussed and directions for future research are offered. / Thesis (BA) — Boston College, 2014. / Submitted to: Boston College. College of Arts and Sciences. / Discipline: College Honors Program. / Discipline: Psychology Honors Program. / Discipline: Psychology.
20

Occupational exposure to blood in selected oral health facilities in Botswana: experiences and practices of oral health staff

Ndlovu, Siphiwo January 2012 (has links)
A research report submitted to the Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, in partial fulfillment of the requirements for the degree of Master of Public Health. Johannesburg, April 2012 / Introduction: Sub-Saharan Africa has a high burden of HIV and other blood borne pathogens. Botswana’s estimated prevalence of HIV and HBV are between 17-40%, and 14 % respectively. Ninety percent of the three million health care workers exposed annually to blood borne pathogens through injury are in developing countries. Previous studies in Botswana indicate 24%-26% health workers sustain needle stick and other sharps injuries annually, posing a threat to them. Dentistry requires work with sharp objects in a confined space; thus oral health workers (OHWs) are at high risk of infection from occupational blood exposures (OBEs). Universal (Standard) Precautions were first recommended by the Center for Disease Control in the United States of America and were adopted in several countries, including Botswana, to minimize the risk of exposure to, and infection from, blood. However, studies in different health care settings, mainly in developed countries, have shown that these guidelines are not always adhered to. Few studies have been done to evaluate their utilization in developing countries. Aim: To quantify the occupational blood exposure experience of OHWs in Botswana’s public service and determine the infection control practices through self reporting and observation. The Objectives were: 1) To determine the demographic profile of the OHWs in Botswana, 2) To determine self reported blood exposure experience of oral health workers within the 12 months prior to the study, 3) To determine self reported infection control practice of oral health workers within the 12 months prior to the study, 4) To determine the knowledge of risks associated with blood borne pathogens amongst oral health workers at the time of the study, 5) To determine, by observation, which v precautions were practiced by oral health workers to prevent exposure at the time of the study, 6) To assess whether there was a written policy available in the dental facility on the prevention and management of occupational blood exposures. Methodology: A cross sectional descriptive survey was carried out using a combination of self reporting and observation. A total of 85 OHWs in 5 of the 6 main oral health facilities were invited to participate. Knowledge of risks pertaining to blood borne pathogens, frequency of blood exposures and practice of universal precautions were assessed. Documents and posters were also reviewed. Results: Sixty eight (80%) OHWs returned the questionnaires and 51 (60%) observations were carried out. At least 80% of respondents had correct knowledge of occurrences that can contribute to the spread of blood borne pathogens in the dental environment. Over 60% were aware of universal precautions and 75% knew that post exposure prophylaxis (PEP) was available at their facilities. Almost 43% of the respondents had experienced blood splashes in the last year and 35.3% experienced needlestick injuries. Half of these reported the injury and 16.2% took PEP. Predictors of needlestick injuries during the previous year were perception of risk, knowledge of and compliance with, Universal Precautions Personal protective equipment was poorly utilised; only 17.6% were observed to use protective eye wear. Two thirds of the respondents were observed to use double-handed recapping. None of the facilities visited had a written protocol displayed. Conclusion and recommendations: The prevalence and reporting of OBEs amongst vi OHWs were comparable with findings of other studies. Self protection through compliance with universal precautions, immunization and post exposure prophylaxis was not fully utilised. The high burden of disease in the country warrants that further efforts be made to protect oral health workers. Appropriate guidelines should be made available at all dental facilities and staff needs to be retrained regarding standard precautions. Monitoring of exposures and vaccination status should be carried out. Further research should be undertaken regarding the poor uptake of prophylaxis.

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