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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.
421

Monitoramento e modelagem de um poço de infiltração de águas pluviais em escala real e com filtro na tampa

Angelini Sobrinha, Lôide 03 May 2012 (has links)
Made available in DSpace on 2016-06-02T20:00:43Z (GMT). No. of bitstreams: 1 4369.pdf: 12366504 bytes, checksum: d0746d888c77116c1453db230bd4d8b3 (MD5) Previous issue date: 2012-05-03 / Financiadora de Estudos e Projetos / The infiltration well as a Best Management Practices (BMPs) stands out because it requires small areas for its implementation an it´s fully applicable to urban lots. This paper presents an experimental study of an infiltration well built in real scale at Universidade Federal de São Carlos SP with the objective of evaluation its performance as a BMP in the control of stormwater runoff and the removal of suspension materials. The soil was characterized as sand loam, and infiltration capacity between 93,98 and 19,24 mm per hour, these values were obtained thought field tests by the inverted well method and the double ring infiltrometer method respectively. The Rain Envelope Method was used for sizing, and the well was intentionally sized at odds with the standards of safety project. With the electronic equipment s and the precipitation measures were monitored 22 real rain events and simulated rain events, during 11 months of the well operation. During this period there was no record of extravasation of the well, representing an efficiency of 100% in reducing the runoff. After eight months of the well operation tests were conducted about the permeability of the geotextile, and the amount of powder material in the aggregate materials content in the well, in other words, the gravel and sand making up the filter cover, and also the qualitative parameters: apparent color and turbidity. The geotextile showed permeability reductions of 50,7%, 7,7% and 21,2% in the samples from the background, the wall sides, and the cover of the well respectively. The well sand filter cover retained 34,8% of fines, while the gravel retained 0,13% for the same period. About the well efficiency analyses in the removing the parameters apparent color and turbidity, it was showed that it wasn t characterized as a treatment unit of these parameters, this fact is due to the quality of water which represents the roof inlet structure. For modeling the Puls method, the saturated soil permeability defined as K non optimized was calculated for each monitored event (Kno). Kno was adjusted by non-linear regression (K optimized - Ko) for each monitored event, restricting the parameters based on values obtained in the field tests, thus for each monitored rain event was obtained two moldings for the constant values of K (Kno and Ko). The model representativeness was evaluated by the coefficients of determination ranging from 0,68 to 0,98 for the events modeled with values from Ko and 0,02 to 0,76 for the Kno, being the Ko most representative for the modeling of Puls. / O poço de infiltração como técnica compensatória de drenagem, se destaca por necessitar de pequenas áreas para sua implantação e ser totalmente aplicável a lotes urbanos. Este trabalho apresenta um estudo experimental de um poço de infiltração construído em escala real no Campus da Universidade Federal de São Carlos SP com o objetivo de avaliar seu desempenho como estrutura compensatória de drenagem urbana no controle do escoamento superficial e na remoção de material em suspensão. O solo foi caracterizado como Areia Média Argilosa SC, com capacidade de infiltração entre 93,38 mm/h e 19,24 mm/h, valores obtidos em ensaios de campo pelos métodos de poço invertido e de duplo anel respectivamente. No dimensionamento utilizou-se o método da Curva Envelope e intencionalmente não seguiram-se as recomendações de segurança para projeto. Com auxílio de equipamentos eletrônicos e das medidas de precipitação, foram monitorados 22 eventos de chuvas reais e chuvas simuladas, durante 11 meses de funcionamento do poço. Neste período não houve registro de extravasamento do poço, representando uma eficiência de 100% na redução do volume escoado. Após oito meses de seu funcionamento foram realizados ensaios da permeabilidade do geotêxtil, do teor de materiais pulverulentos dos agregados ao poço, ou seja, a brita e a areia que compõem o filtro da tampa, e dos parâmetros qualitativos: cor aparente e turbidez. O geotêxtil apresentou redução média da permeabilidade de 50,7%, 7,7% e 21,2% nas amostras do fundo, paredes e tampa do poço respectivamente. A areia do filtro da tampa reteve 34,8% de finos, enquanto a brita reteve 0,13% de finos no mesmo período. Com relação á remoção da cor aparente e da turbidez constou-se que o poço não caracteriza-se como uma unidade de tratamento destes parâmetros, tal fato deve-se à qualidade da água do telhado que representa a entrada de água na estrutura. Para a modelagem pelo método de Puls a permeabilidade do solo saturado definida como K não otimizado (Kno) foi calculada para cada evento monitorado. O Kno foi ajustado através de regressão não-linear (K otimizado - Ko), restringindo os parâmetros com base nos valores obtidos nos ensaios de campo, dessa forma para cada evento monitorado obteve-se duas modelagens para os valores de K constantes (Kno e Ko). A representatividade do modelo foi avaliada por meio dos coeficientes de explicação que variaram de 0,68 a 0,98 para os eventos modelados com os valores de Ko, e de 0,02 a 0,76 para o Kno, sendo o Ko mais representativo para a modelagem de Puls.
422

Assessment of ephemeral gully erosion using topographic and hydrologically based models in Central Kansas

Sekaluvu, Lawrence January 1900 (has links)
Master of Science / Department of Biological and Agricultural Engineering / Aleksey Sheshukov / The global requirements for food and agricultural products have increased enormously in recent years mainly due to increase in global population. More land is brought under human development and cultivation including marginal lands that are susceptible to degradation processes of erosion, waterlogging, and depletion of organic matter. The resulting effects include; deprivation of the roles performed by the environment, high costs of water treatment, and sedimentation of water reservoirs. This study aims at assessment of ephemeral gully (EG) erosion using topographic and hydrologically based models in two paired watersheds in Central Kansas. The effects of best management practices (BMPs) implementation on EG formation, and erosion rates within the watershed are discussed. The topographic index (TI) models used include: slope area model (SA), compound topographic index model (CTI), wetness topographic index model (WTI), slope area power (SA2), kinematic wave model (nLS), and modified kinematic wave model (nLSCSS). EGs predicted by each model threshold were compared with observed EGs obtained through digitization and field reconnaissance. The agreement of thresholds obtained from location and length approaches were compared by means of drainage density concept. Statistical analysis was performed by error matrix for EG location analysis, and root mean square error (RMSE) and Nash–Sutcliffe efficiency (NSE) for EG length analysis. A TIN-based real-time integrated basin simulator (tRIBS) model, a physically-based, distributed hydrological model was coupled with an EG erosion component (Foster and Lane model) to estimate the erosion rates, and effect of installation of BMPs on reduction of EG erosion rates from agricultural fields. The results indicated that TI models could predict EG location with a maximum total accuracy of 70%. The effectiveness of TI models at prediction of EGs is affected by watershed features such as installed structural best management practices, roads, and culverts. The CTI model outperformed all the TI models at prediction of EGs with maximum Kappa and NSE values of 0.32 and 0.55 respectively, and a minimum RMSE value of 0.087 m. Structural BMPs are effective at controlling erosion from croplands, however, the effectiveness of structural BMPs at reduction of sediment loadings from EGs vary depending on surface cover, and BMP geometry.
423

Soil testing and nutrient application practices of agricultural retailers in the Great Lakes Region

Sisung, Theresa January 1900 (has links)
Master of Agribusiness / Agricultural Economics / Terry Griffin / Agricultural runoff containing phosphorus is believed to be a major contributor of algae blooms in the Western Lake Erie Basin. However, the implementation of best management practices (BMPs) can be used to help reduce the runoff of phosphorus. This research involved conducting surveys to analyze the current implementation of BMPs in Michigan and Indiana. The hypothesis is that the survey results are similar between the two states. An additional hypothesis is that the Michigan and Indiana results are similar to results from two other studies that were previously conducted. The results from this research generally support the hypothesis that a similar number of farmers in Michigan and Indiana are already implementing best management practices on their farms. In addition to the results being similar across Michigan and Indiana, there is also some evidence that shows that the results are similar to studies from the Ohio State University (LaBarge and Prochaska 2014), CropLife magazine (Erickson and Widmar 2015) and NRCS (U.S. Department of Agriculture, Natural Resources Conservation Service 2016); however upon further investigation there are distinct differences before and after media mentions of ramifications from the Lake Erie algal blooms. While it is difficult to force farmers to implement BMPs, the results of this study may help to educate them, which may cause them to add these practices to their operations.
424

Call to the post: an analysis of Montgomery County equine operators’ motivation for adoption of conservation practices

Ingram, Shelly V. January 1900 (has links)
Master of Science - Agricultural Education and Communication / Department of Communications and Agricultural Education / Lauri M. Baker / The equine industry is an established part of Maryland Agriculture; the most recent equine census placed 79,100 equines valued at approximately $714 million in the state, with approximately ten percent of those animals housed in Montgomery County. But, equine operators are a unique demographic in the agricultural realm. They are not managing their lands to produce food or fiber and often are employed in other professions unrelated to agriculture. Unlike other agricultural operators, they are often unaware of conservation terms or practices and programs available to help implement these practices on their land. The basic objective of this study was to explore the level of understanding equine operators in Montgomery County, Maryland have of conservation best management practices (BMPs), associated cost-share programs, industry regulations and the aspects and methods of communication that influence them in gaining awareness of and the adoption of these practices on their properties. The study applied the tenets of the decomposed theory of planned behavior (DTPB), which combines the theory of planned behavior (TPB), diffusion of innovation theory (DOI) and economic constraint theory gathered through semi-structured qualitative interviews with participants, selected using purposive and snowball sampling. Utilizing the grounded theory method to discover emerging patterns in the data resulting from these interviews aided in identifying the most effective means of educating equine operators regarding BMPs and increasing the adoption of these practices on equine properties within the County. Equine operators in the study were found to use a variety of informational sources, had a high level of adaptation of the BMPs they used and overall saw their role as land stewards as an important aspect of their environmental actions.
425

Experiences and pedagogy: a qualitative case study that examines teaching experiences, philosophies, and best practices of University Distinguished Teaching Scholars at Kansas State University

Vaca-Cárdenas, Mónica Elva January 1900 (has links)
Doctor of Philosophy / Curriculum and Instruction / F. Todd Goodson / Kay Ann Taylor / This qualitative case study examined how successful professors who were awarded the Coffman Chair for University Distinguished Teaching Scholars at Kansas State University describe their teaching experiences, philosophies, and best practices in undergraduate teaching and learning. Educators today are concerned about what are the best practices to educate new generation students to survive in a rapidly changing world. Additionally, because most research focus on best practices on the implementation or evaluation of a specific methodology, method, or strategy in one particular course or program, this research addressed the need to investigate the teaching experiences, philosophies, and best practices of outstanding award winner professors in different areas; to understand the challenges they face and the ways they handle undergraduate teaching and learning. This qualitative case study was informed by Critical Theory as the theoretical framework, grounded in Constructivism, because critical theory cares about social justice while abandoning obsolete, elitist and antidemocratic features of traditional concepts of education. Seven distinguished teaching scholars, who belong to Psychological Sciences, School of Integrated Studies, Political Sciences, Horticulture and Natural Resources, Modern Languages, English, and Physics departments, voluntarily participated in this study. Multiple methods were used to collect data including demographic questionnaires, semi-structured interviews (time line elicitation interviews, formal interviews, and photo elicitation interview), analysis of documents, and journaling. Seven themes emerged from my findings. The first theme identified the influential people and struggles encountered by professors when they were students. The second identified events that led professors in choosing their major, why they became teachers, and their teaching strengths and passions. The third identified the challenges they face when teaching undergraduate students and mentoring support received as professors. The fourth identified how participants described themselves as successful professors and the way they organize and balance their academic and personal life. The fifth identified specific educational theories the professors apply in their teaching, the insights of their teaching philosophies, and their thoughts about the importance of education. The sixth identified the way professors decide the curriculum to teach and the way they evaluate their students. Finally, the seventh theme identified the significant work they did as recipients of the Coffman Chair for University Distinguished Teaching Scholar, and their teaching best practices. Recommendations for practice and future research were also addressed. Thus, this study contributes to the understanding of teaching experiences, philosophies, and best practices of successful professors in undergraduate teaching and learning, based on evidence which is the personal experiences of the participants for the benefit of every person involved in education.
426

Impact of a Non-Traditional Research Approach

January 2014 (has links)
abstract: Construction Management research has not been successful in changing the practices of the construction industry. The method of receiving grants and the peer review paper system that academics rely on to achieve promotion, does not align to academic researchers becoming experts who can bring change to industry practices. Poor construction industry performance has been documented for the past 25 years in the international construction management field. However, after 25 years of billions of dollars of research investment, the solution remains elusive. Research has shown that very few researchers have a hypothesis, run cycles of research tests in the industry, and result in changing industry practices. The most impactful research identified in this thesis, has led to conclusions that pre-planning is critical, hiring contractors who have expertise will result in better performance, and risk is mitigated when the supply chain partners work together and expertise is utilized at the beginning of projects. The problems with construction non-performance have persisted. Legal contract issues have become more important. Traditional research approaches have not identified the severity and the source of construction non-performance. The problem seems to be as complex as ever. The construction industry practices and the academic research community remain in silos. This research proposes that the problem may be in the traditional construction management research structure and methodology. The research has identified a unique non-traditional research program that has documented over 1700 industry tests, which has resulted in a decrease in client management by up to 79%, contractors adding value by up to 38%, increased customer satisfaction by up to 140%, reduced change order rates as low as -0.6%, and decreased cost of services by up to 31%. The purpose of this thesis is to document the performance of the non-traditional research program around the above identified results. The documentation of such an effort will shed more light on what is required for a sustainable, industry impacting, and academic expert based research program. / Dissertation/Thesis / Masters Thesis Construction 2014
427

Measuring the Construction Performance in Saudi Arabia and Proposing New Procurement Model Based on BV PIPS (A University Case Study)

January 2016 (has links)
abstract: Saudi Arabia has been facing issues with completing construction projects on time and on budget. It has been documented that 70% of public construction projects are delayed. Studies have identified the low-bid delivery method as an important factor in causing such delays. The procurement system (low-bid) ignores contractors’ performance, and that is reflected in projects’ performance. A case study was performed, at a University campus in northern Saudi Arabia, identifying the major causes of project delays and cost overruns. The University was experiencing delays from 50% to 150%. Also, the actual project costs for four projects were examined and found that all four projects’ costs were higher than the original bid. The delay and cost overruns factors were gathered from the University engineers. A literature research identified one construction management method, best value performance information procurement system (BV PIPS), has documented multiple times its ability to improve project performance. In a comparison using the result of a case study and the results of (BV PIPS), Saudi Arabia’s delivery system was identified as a potential cause of project performance issues. The current procurement system was analyzed and modified to adapt with the (BV PIPS). The proposed procurement system using BV PIPS, which can be implemented in Saudi Arabia, was created with owner side. A large survey was conducted of 761 classified contractors and 43 universities’ representatives who rated causes of delay factors and cost overruns. The delay factors were then compared to delay factors experienced on Saudi construction projects, identified by performing a literature research. The comparison identified 14 important causes of delays. Moreover, the survey showed that classified contractors and universities’ representatives unsatisfied with low-bid, and they agreed with BV PIPS which selecting vendors based on performance with price. The proposed model required a submitted level of experience (LE), risk assessment (RA), and value added (VA). Besides, project managers of vendors should be interviewed during the clarification phase. In addition, venders should submit the project’s scope, technical schedule, milestone schedule, and risk management plan. In the execution phase, vendors should submit a weekly risk report (WRR) and director’s report (DR). / Dissertation/Thesis / Doctoral Dissertation Construction 2016
428

Downward Wage Rigidity, Corporate Investment, and Firm Value

January 2017 (has links)
abstract: Firms reduce investment when facing downward wage rigidity (DWR), the inability or unwillingness to adjust wages downward. I construct DWR measures and exploit staggered state-level changes in minimum wage laws as an exogenous variation in DWR to document this fact. Following a minimum wage increase, firms reduce their investment rate by 1.17 percentage points. Surprisingly, this labor market friction enhances firm value and production efficiency when firms are subject to other frictions causing overinvestment, consistent with the theory of second best. Finally, I identify increased operating leverage and aggravation of debt overhang as mechanisms by which DWR impedes investment. / Dissertation/Thesis / Doctoral Dissertation Business Administration 2017
429

Shifting from Management to Leadership: A Procurement Model Adaptation to Project Management

January 2017 (has links)
abstract: The construction industry is performing poorly regarding project management and service delivery. On average, global projects are over-budget, delayed, and met with unsatisfactory results according to buyers. To mitigate poor performance, the project management career path has been heavily researched and continually developed over the last century. Despite the published advances in project management approaches and tools, project performance continues to suffer. This research seeks to conduct an exploratory analysis of current project management and other approaches and determine how they affect project performance. Through a detailed literature search, the researcher identified a procurement model that is more heavily documented as high performing than all other approaches. The researcher proposed that this model may be a solution to assist project managers with the delivery of high performing services. The model is called the Best Value Approach (BVA). The BVA focuses on leadership, non-technical communication, quality assurance, and transparent project execution. To test the effectiveness of its practices, the researcher modified and adapted the BVA into a project management approach and tested it on a large-scale government project. During the case study test, the researcher observed that there were two primary project management roles in the supply chain; the buyer’s and vendor’s project managers. The case study resulted in the large government organization receiving more work and increased their satisfaction of the work received by 22 percent from the previous year. To further test the project management adapted BVA, the researcher conducted a classroom case-study in which students learned and implemented the BVA practices on real-time, small-scale industry projects. Results include cost savings of $100,000 for 10 companies over 24 projects, cost avoidance of over $4.5M, and a 9.8/10 customer satisfaction [in terms of the companies’ satisfaction with the deliverables produced on each project]. These results suggest that the BVA practices may effectively improve the performance of project delivery, and may be a viable new project management approach to train future project managers. Out of the two project manager roles, it is proposed that the buyer’s project manager may receive the most benefit. Additional research is needed on the other approaches to compare quantitative project performance, and run repeated testing on the potential new project management approach. / Dissertation/Thesis / Doctoral Dissertation Construction Management 2017
430

Módulos de suavidade e relações com K-funcionais / Moduli of smoothness and relations with K-functional

Cristiano dos Santos 30 August 2017 (has links)
Neste trabalho, primeiramente, exploramos certos módulos de suavidade e K - funcionais definidos na esfera unitária m - dimensional e suas propriedades, dando prioridade a suas equivalências assintóticas e comparação com o erro de melhor aproximação. Uma das principais referências utilizadas foi (DAI; XU, 2010). Posteriormente, consideramos um módulo de suavidade e um K-funcional em espaços mais gerais, os espaços compactos 2-homogêneos, classe de espaços esta que contém a classe das esferas. A relação entre estes objetos e o raio de aproximação do operador translação (translação esférica, no contexto esférico) foi estudada. As principais referências foram (PLATONOV, 2009) e (PLATONOV, 1997). / In this work, we firstly explored certain moduli of smoothness and K - functionals defined on the m-dimensional unit sphere and their properties, mainly their asymptotic equivalence and relation to the best approximation error. The main reference is (DAI; XU, 2010). Later we consider a moduli of smoothness and a K-functional on a general setting, namely two-point homogeneous spaces, which has the unit spheres as one of its classes. Relations between those tools and the rate of approximation of the shiffting operator were studied. The main references here were (PLATONOV, 2009) and (PLATONOV, 1997).

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