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Theoretical study of diffraction by straight and ragged edge noise barriers /Menounou, Pinelopi, January 1998 (has links)
Thesis (Ph. D.)--University of Texas at Austin, 1998. / Vita. Includes bibliographical references (leaves 271-278). Available also in a digital version from Dissertation Abstracts.
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Theoretical effects of consolidation on solute transport in soil barriers.Lewis, Timothy January 2009 (has links)
Research Doctorate - Doctor of Philosophy (PhD) / Consolidation of clayey contaminant barriers, such as are employed as landfill liners, has been postulated as a cause of accelerated transit of contaminants and hence their earlier than expected appearance in secondary leachate. This proposition is theoretically investigated in this thesis using a novel large-deformation, one-dimensional continuum model of coupled mechanical consolidation and solute transport. The model is a generalization of existing coupled consolidation and solute transport models described in the literature. It takes into account both non-linearities in geometry as well as material constitutive relations. The latter relate the compressibility, hydraulic conductivity and effective diffusion coefficient to the deformation of the soil. In addition to providing details of the governing equations and constitutive relations, a detailed derivation of the three classical one-dimensional consolidation boundary conditions, i.e. undrained top and drained bottom, drained top and undrained bottom, drained top and bottom is also given. From the continuum model formulation, a numerical model was developed using proprietary finite element software – FEMLAB 2.3. The numerical model is verified by comparing results with those produced from other recently developed consolidation – transport models. In the course of conducting these comparisons, some results from a recent modelling investigation indicating that a twenty-fold reduction in the transit time of contaminants across a composite soil – geomembrane barrier may be possible were re-examined. This comparison reveals some apparent errors in the original analysis and indicates that the predicted large acceleration of contaminant transport induced by consolidation is probably unrealistic. The model is subsequently applied to a case study of a clay liner and geomembrane system. Results obtained are compared with those from various simplified models, including a “diffusion-only” (i.e. a rigid soil) model traditionally used in contaminant barrier design. For barriers incorporating low compressibility soils (such as well compacted clays), there is little difference between contaminant transit times predicted by the two models. However, for contaminant barriers incorporating more compressible soils, consolidation is shown to be capable of accelerating transport. These results indicate the potential importance of accounting for the effects of soil consolidation and they highlight some limitations of existing models when modelling solute transport through composite barriers utilizing soft soils. Based on these limited results, a way of taking into account soil consolidation using simplified models is suggested. In the penultimate chapter of this thesis, an extensive parametric sensitivity analysis of coupled consolidation and solute transport in composite contaminant barrier systems is presented. The analysis incorporates results of more than 3000 simulations for various combinations of barrier thickness, waste loading rate, initial void ratio, compression index, hydraulic conductivity and dispersion coefficient. Results are succinctly presented using dimensionless plots, which allow the comparison of results for a large number of parameter values, and hence, the clear identification of the most important factors affecting contaminant transport through a consolidating composite barrier system. The results demonstrate that there exists a pessimum rate of consolidation for which the contaminant transit time is minimised. In cases of extremely high barrier compressibility it is shown that an order of magnitude reduction in contaminant transit time may arise due to coupling between solute transport and consolidation. For barriers of low compressibility and porosity, such as well-engineered composite compacted clay landfill liners, it is found that the contaminant transit time is far less affected, though it may still be reduced by up to 30%. In general, the results suggest that the use of a coupled consolidation–contaminant transport model may be required for informed and conservative contamiant barrier design, especially if relatively compressible earthen components are utilised.
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Cultural entry barriers for SMEs : An exploratory study of cultural entry barriers for foreign SMEs entering JapanBillore, Gautam, Engkvist Borg, Jakob January 2014 (has links)
Purpose: The purpose of this paper is to study the cultural barriers faced by Small and Medium Enterprises (SMEs) in entering Japanese market and to see how the successful companies have overcome the barriers. Design/methodology/approach: An exploratory case study with qualitative research through semi-structured interviews (telephonic and Skype) with foreign SMEs in Japan. 17 interviews could be conducted in 12 companies out of 76 companies contacted. Theoretical framework: The theoretical framework encompasses barriers studied by Namiki (1998) for classification of the entry barriers and applied the same on SMEs. The cultural aspect has been deployed in accordance to theory of House et al. (2004), Trompenaars & Hampden-Turner (2012) and on the cultural dimensional framework of Hofstede et al. (2010). It further includes language in intercultural communication and barriers related to it. Findings: The study identifies that the business culture perceived by foreign SMEs in Japan is almost similar to the national culture identified by Hofstede et al. (2010), but only three out of five cultural dimensions studied and the language have emerged as barriers for the foreign SMEs to do business in Japan. It was also found that to adapt to the Japanese business culture in general, engage in business relationship and to use senior bi-lingual Japanese staff, was keys to success for the foreign SMEs. Managerial implications: It is recommended that managers should study previous literature on cultural barriers as it most likely also applies to SMEs. It is also recommended to use Japanese bi-lingual staff and to establish relationships with Japanese companies as soon as possible. Limitations: The study was conducted with interviews of only twelve SMEs in Japan. The study was confined to qualitative method and a quantitative study with larger number of companies could have fetched more quantifiable results. Originality/value: This paper is one of the first to analyse the cultural barriers exclusively for the foreign SMEs in Japan with interviewing firms doing business in Japan. Keywords: Entry barriers, cultural barriers, SMEs, Japan market. Classification: Exploratory, qualitative study.
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Theoretical effects of consolidation on solute transport in soil barriers.Lewis, Timothy January 2009 (has links)
Research Doctorate - Doctor of Philosophy (PhD) / Consolidation of clayey contaminant barriers, such as are employed as landfill liners, has been postulated as a cause of accelerated transit of contaminants and hence their earlier than expected appearance in secondary leachate. This proposition is theoretically investigated in this thesis using a novel large-deformation, one-dimensional continuum model of coupled mechanical consolidation and solute transport. The model is a generalization of existing coupled consolidation and solute transport models described in the literature. It takes into account both non-linearities in geometry as well as material constitutive relations. The latter relate the compressibility, hydraulic conductivity and effective diffusion coefficient to the deformation of the soil. In addition to providing details of the governing equations and constitutive relations, a detailed derivation of the three classical one-dimensional consolidation boundary conditions, i.e. undrained top and drained bottom, drained top and undrained bottom, drained top and bottom is also given. From the continuum model formulation, a numerical model was developed using proprietary finite element software – FEMLAB 2.3. The numerical model is verified by comparing results with those produced from other recently developed consolidation – transport models. In the course of conducting these comparisons, some results from a recent modelling investigation indicating that a twenty-fold reduction in the transit time of contaminants across a composite soil – geomembrane barrier may be possible were re-examined. This comparison reveals some apparent errors in the original analysis and indicates that the predicted large acceleration of contaminant transport induced by consolidation is probably unrealistic. The model is subsequently applied to a case study of a clay liner and geomembrane system. Results obtained are compared with those from various simplified models, including a “diffusion-only” (i.e. a rigid soil) model traditionally used in contaminant barrier design. For barriers incorporating low compressibility soils (such as well compacted clays), there is little difference between contaminant transit times predicted by the two models. However, for contaminant barriers incorporating more compressible soils, consolidation is shown to be capable of accelerating transport. These results indicate the potential importance of accounting for the effects of soil consolidation and they highlight some limitations of existing models when modelling solute transport through composite barriers utilizing soft soils. Based on these limited results, a way of taking into account soil consolidation using simplified models is suggested. In the penultimate chapter of this thesis, an extensive parametric sensitivity analysis of coupled consolidation and solute transport in composite contaminant barrier systems is presented. The analysis incorporates results of more than 3000 simulations for various combinations of barrier thickness, waste loading rate, initial void ratio, compression index, hydraulic conductivity and dispersion coefficient. Results are succinctly presented using dimensionless plots, which allow the comparison of results for a large number of parameter values, and hence, the clear identification of the most important factors affecting contaminant transport through a consolidating composite barrier system. The results demonstrate that there exists a pessimum rate of consolidation for which the contaminant transit time is minimised. In cases of extremely high barrier compressibility it is shown that an order of magnitude reduction in contaminant transit time may arise due to coupling between solute transport and consolidation. For barriers of low compressibility and porosity, such as well-engineered composite compacted clay landfill liners, it is found that the contaminant transit time is far less affected, though it may still be reduced by up to 30%. In general, the results suggest that the use of a coupled consolidation–contaminant transport model may be required for informed and conservative contamiant barrier design, especially if relatively compressible earthen components are utilised.
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Highway traffic noise barrier overlap gap modelClum, Craig M. January 1997 (has links)
Thesis (M.S.)--Ohio University, June, 1997. / Title from PDF t.p.
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The chemistry of bridgehead diphosphinesRead, David January 2000 (has links)
No description available.
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Nonequilibrium processes in heterostructures under the influence of internal and external magnetic fieldsHeide, Carsten January 1997 (has links)
No description available.
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Perceived Barriers to Career Self-Exploration for Adults with Learning DisabilitiesHarris, Alesha Nicole January 2016 (has links)
Thesis advisor: Janet E. Helms / Research regarding the career exploration process for adults with reading disabilities and ADHD who participate in Adult Basic Education (ABE) programs is limited. Due to a lack of career development resources in ABE programs, adults with reading disabilities and ADHD do not always have the opportunity to engage in career exploration activities that might help them make satisfying career decisions. In career development theory, self-determination is the capacity to identify personal goals and is considered crucial to overcoming barriers and making meaningful career choices. In the present study, a model was proposed and tested that examined self-determination as a mediator of the hypothesized relationships between perceived career and educational barriers and career development outcomes. Adults with reading disabilities and ADHD from ABE programs (N = 83) completed a demographic questionnaire and screening measures intended to classify them according to type of disability (i.e., reading, ADHD, and combined reading and ADHD). They also completed measures of perceived educational and career barriers, components of self-determination, and career self-efficacy. Multivariate multiple regression analyses were used to investigate hypotheses derived from the proposed model. The results revealed that experiences of perceived educational barriers, but not career barriers, were related to low levels of career decision-making self-efficacy and self-determination; the competence component of self-determination was associated with higher levels of career decision-making self-efficacy. Overall, the results suggested that self-determination partially mediated the relationship between perceived educational barriers and career decision-making self-efficacy. The findings indicate that, for ABE adults with reading disabilities and ADHD, having a sense of one’s own expertise is important for overcoming barriers and feeling confident in making career decisions. Discussions included methodological limitations and implications for practice and research. / Thesis (PhD) — Boston College, 2016. / Submitted to: Boston College. Lynch School of Education. / Discipline: Counseling, Developmental and Educational Psychology.
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You Are Who You Eat With: Barriers to Adopting Animal-Free DietsFranko, Emily January 2017 (has links)
Thesis advisor: Juliet Schor / This study investigates the barriers to adopting vegetarian and vegan diets. Why do people who try to adopt these diets fail to maintain them? Why do people who identify as vegetarian or vegan allow exceptions in their diets? This study used a series of intensive interviews and a survey to answer these research questions. Interviews and survey responses revealed the following barriers to maintaining vegetarianism/veganism: social barriers, a lack of vegetarian/vegan options, a loss of a “black-and-white” perspective on diet, nutritional barriers, personal cravings, time barriers, and a tendency to subscribe to gendered meanings of meat eating. Social barriers were the most salient challenges for study participants. Participants indicated that they commonly encountered several types of social barriers while attempting to maintain vegetarian/vegan diets. This study concluded that cultural norms must change in order for people to find vegetarian/vegan diets more viable. Most significantly, this study found that having a supportive social network of people who adhere to a similar diet is extremely important for people as they try to maintain vegetarianism/veganism. / Thesis (BA) — Boston College, 2017. / Submitted to: Boston College. College of Arts and Sciences. / Discipline: Departmental Honors. / Discipline: Sociology.
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Physical Activity Levels and Barriers to Exercise in Individuals with Low Bone Mineral DensityNg, Helen January 2013 (has links)
Background: Fractures are a major health concern for older adults, especially for those with osteoporosis or low bone mineral density (BMD). Physical activity and exercise can be important self-management strategies for older adults with osteoporosis or low BMD to prevent fractures.
Objectives: This study examined the physical activity and exercise levels of older adults with low BMD and determined the proportion of individuals meeting the Canadian Physical Activity Guidelines. As well, this study characterized perceived individuals’ barriers to exercise and their willingness to pay for different methods of delivering exercise information. Secondary goals of this study were to investigate correlates of aerobic exercise and factors associated with meeting moderate- to vigorous-intensity aerobic physical activity guidelines.
Methods: Individuals aged 50 years or older with a self-reported diagnosis of low BMD were recruited from the Canadian Osteoporosis Patient Network (COPN) and an osteoporosis public education event. Questionnaires were distributed online and through mail to individuals interested in participating. Participants were asked about the amount of time they spent doing moderate- and vigorous-intensity physical activity (MVPA) and the frequency at which they did strength and balance training per week. Also, participants were asked about potential barriers to exercise that they perceive, the strength at which they perceived those barriers at, and their interest in and willingness to pay (WTP) for different methods of delivering exercise information. Information about different factors affecting exercise behaviour such as risk perception, intention to exercise, and exercise self-efficacy were collected as well.
Results: The total number of participants included in this study was 130 (mean [SD] age 66.32 [8.81] years). The mean (SD) time spent doing MVPA per week reported by participants was 831.35 (1065.43) minutes. The mean (SD) days per week that participants reported doing strength and balance training were 1.90 (1.66) and 1.36 (1.84), respectively. Sixteen individuals (12.3%) did not meet the guideline of engaging in at least 150 minutes of MVPA per week. Forty-one participants (31.5%) did not report doing any strength training and sixty-five individuals (50%) did not report doing any balance training. The most prevalent barriers to exercise that were reported was having no enjoyment for exercise (51.2%) , having no company to exercise with (47.2%), and health-related problems (37.5%). Although a majority of participants expressed interest in all methods of delivering exercise information, the mean WTP for a group exercise class and for training one-on-one with a certified personal trainer was lower than the suggested amounts that they would normally cost. Factors associated with meeting MVPA recommendations were intention to exercise (p = 0.03), exercise self-efficacy (p = 0.03), and strength of perceived barriers (p = 0.02).
Conclusion: Many older adults with low bone mineral density are not meeting established physical activity guidelines. Greater measures need to be taken in promoting strength and balance training among these individuals. Addressing barriers to exercise may be an effective strategy to encourage individuals with low bone mineral density to become more active.
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