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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.
31

Avaliação de um sistema de irrigação por aspersão do tipo pivô central móvel /

Lima, Adenilsom dos Santos, 1975 January 2003 (has links)
Orientador: Antonio Evaldo Klar / Resumo: Um sistema de irrigação deve possibilitar o manejo eficiente da lâmina de água aplicada. Para tal, é necessário avaliar o desempenho do sistema em operação. Este trabalho teve por objetivo avaliar a uniformidade de distribuição de água em um sistema de irrigação por aspersão do tipo pivô central rebocável operando em duas áreas com condições de desníveis e comprimento de adutora distintas. O ensaio foi realizado na fazenda Buriti Mirim, no município de Angatuba - SP, com duas regulagens no relê percentual, a 15% e 100%, com os pluviômetros espaçados de três em três metros, colocados em média a 0,50m de altura em relação ao solo. Para a avaliação do desempenho do sistema, utilizou-se o coeficiente de uniformidade de Christiansen (CUC) e o coeficiente de uniformidade de distribuição (CUD), baseados a partir das lâminas de água coletadas em pluviômetros instalados sob os emissores do equipamento. Verificou-se que todos os valores do CUC ficaram abaixo dos valores mínimos recomendados demonstrando baixa eficiência na distribuição de água do equipamento, e que as mudanças de posição afetaram os valores de lâmina d'água aplicados em relação aos valores de projeto. / Abstract: An irrigation system must possibilities the handling of the water with the maximum efficacy. For such, is necessary to evaluate the performance of the system in operation. Some parameters are used in the evaluations, the most important are: the uniformity of water distribution (CUD), and the Christiansen uniformity coefficient (CUC). So, the study had for objective to evaluate the uniformity of water distribution sprinkler system of central pivot removable that operates in three different areas, in different levels and distinct length of main line, comparing and quantifying the values of uniformity and water table average applied in two positions of operation of the equipment, as well as the operational conditions of the system in function of these changes. The study was carried through at Buriti-Mirim farm, in Angantuba - SP, with two regulations in rereads percentage, 15% and 100%, with the rain gauges spaced three meters each, distributed 0,50m average above soil surface. For the evaluation of the performance of the system, the Christiansen uniformity coefficient was used (CUC), based from the water table collected in rain gauges installed under the equipment sprinklers. It was verified that all the values for the uniformity coefficients had been below of the recommended minimum values demonstrating low efficiency in the water distribution of the equipment, and that the position changes had affected the values water table applied in relation to the values of project. / Mestre
32

Modelagem probabilística das lâminas de água aplicadas na cultura do arroz por um equipamento mecanizado de irrigação tipo lateral móvel / Probabilistic modeling of water depths applied in a rice crop by a mechanical lateral move irrigation equipment

Nörenberg, Bernardo Gomes 08 August 1925 (has links)
Submitted by Aline Batista (alinehb.ufpel@gmail.com) on 2016-06-03T22:26:19Z No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Modelagem probabilística das lâminas de água aplicadas na cultura do arroz.pdf: 1760930 bytes, checksum: dc4b81628d7ef86734f85936c2e9f01a (MD5) / Approved for entry into archive by Aline Batista (alinehb.ufpel@gmail.com) on 2016-06-03T22:26:47Z (GMT) No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Modelagem probabilística das lâminas de água aplicadas na cultura do arroz.pdf: 1760930 bytes, checksum: dc4b81628d7ef86734f85936c2e9f01a (MD5) / Approved for entry into archive by Aline Batista (alinehb.ufpel@gmail.com) on 2016-06-03T22:27:07Z (GMT) No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Modelagem probabilística das lâminas de água aplicadas na cultura do arroz.pdf: 1760930 bytes, checksum: dc4b81628d7ef86734f85936c2e9f01a (MD5) / Made available in DSpace on 2016-06-03T22:27:29Z (GMT). No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Modelagem probabilística das lâminas de água aplicadas na cultura do arroz.pdf: 1760930 bytes, checksum: dc4b81628d7ef86734f85936c2e9f01a (MD5) Previous issue date: 8-08-25 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / A agricultura irrigada, em um cenário mundial, é o setor que mais utiliza água, sendo que, no Brasil, especialmente no estado do Rio Grande do Sul, o método de irrigação mais utilizado é o de irrigação por superfície com o sistema de inundação contínua, amplamente utilizado na cultura do arroz. Entretanto, a irrigação por aspersão, se manejada adequadamente, tem potencial de suprir a demanda hídrica da cultura utilizando um volume menor de água. Assim sendo, este estudo teve por objetivo avaliar um equipamento de irrigação mecanizado tipo lateral móvel operando em condições de vento, assim como testar a adequabilidade com que as distribuições de probabilidade normal, uniforme, gama, Weibull e logística descrevem a distribuição da lâmina de água aplicada por um equipamento de irrigação mecanizado tipo lateral móvel utilizado na cultura do arroz, operando em condições de vento na região sul do Rio Grande do Sul, assim como, gerar um modelo para simulação dos parâmetros das distribuições que melhor representarem o perfil da lâmina aplicado pelo equipamento por meio da velocidade média do vento. Para isso foram realizados 29 ensaios de campo no equipamento de irrigação, o qual contém, em 5 vãos, 265 metros de comprimento, equipado com emissores modelo I-Wob com placa oscilante de 9 jatos. Para coletar a lâmina de água aplicada pelo equipamento na área irrigada foram utilizadas duas linhas de coletores paralelas, distantes 5 m e, cada uma, contendo 88 coletores espaçados 3 m entre si. Foi observado a alta uniformidade de aplicação de água do equipamento, mesmo em condições elevadas de vento (V > 6,00 m.s-1). Além disso, as distribuições normal, logística e Weibull de probabilidades se ajustaram adequadamente à maioria dos ensaios de campo. Os parâmetros de escala das distribuições normal e logística tiveram uma boa explicação na sua variação em função da velocidade média do vento, resultado esse não obtido para a distribuição Weibull. Os modelos propostos através dos parâmetros de Escala das distribuições normal e logística representaram de forma adequada, o desempenho do equipamento de irrigação mecanizado do tipo lateral móvel utilizado na irrigação do arroz na região sul do Rio Grande do Sul. / On a world stage, the irrigated agriculture is the activity that uses more water, and, in Brazil, especially in the state of Rio Grande do Sul, the most widely used method of irrigation is surface irrigation with continuous flooding system, widely used in rice cultivation. However, sprinkler irrigation, if managed properly, has the potential to meet the water demand of the crop using a smaller volume of water. Therefore, this study aimed to evaluate a mechanical lateral move irrigation equipment used on a rice crop and operating in windy conditions, as well as test the adequacy with which the distributions of normal probability, uniform, gamma, Weibull and logistics describe the distribution of water depth applied by the mechanical lateral, operating in windy conditions in southern of Rio Grande do Sul, as well as generate a model to simulate the parameters of the distributions that better represent the profile of the applied depth by the equipment through the average wind speed. To do this were performed 29 in-field tests of the irrigation equipment, which contains, in 5 spans 265 meters, equipped with I-Wob emitters with a 9-jets rotating plate. To collect water depth applied by the equipment in the irrigated area were used two parallel lines of catch cans distant 5 m and each containing 88 catch cans spaced 3 m from each other. It was observed high uniformity water application equipment even in high wind conditions (V> 6.00 ms-1). Furthermore, the normal distribution, logistics and Weibull probability is suitably adjusted to the most in-field tests. The range of parameters of normal and logistic distributions have a good explanation in its variation as a function of wind speed, a result not obtained for the Weibull distribution. The models proposed by the scale parameters of the normal distribution and logistics represented properly, the performance of the mechanical lateral move irrigation equipment operating on a rice crop in the south of Rio Grande do Sul.
33

The effects of nutrient uniformity and modified feed processing on animal performance

Clark, Patrick M. January 1900 (has links)
Doctor of Philosophy / Department of Grain Science and Industry / Keith C. Behnke / A series of experiments were conducted evaluating the effects of marker selection and mix time on feed uniformity, feed uniformity on animal performance, and the addition of cracked corn to a concentrate pellet on broiler performance. Utilizing a common corn-soybean meal based poultry diet, as mix time increased, there was an overall decrease in % Coefficient of Variation (CV) observed, which was independent of which marker was used. Crude protein should be considered to be an inferior marker as several ingredients in the batch contribute some level of protein and overall decreased numerically less than 1% CV. Synthetic amino acids (methionine and lysine) prevailed as the most consistent markers reducing in magnitude by 60.32% and 55.97% (methionine and lysine, respectively). To evaluate the effects of feed uniformity on broiler performance, as determined by CV, methionine was added to a basal diet and mixed for 10, 20, 30, 40, or 120-s, with methionine being the only ingredient varying. During the starter period (d 0 to 16) ADG increased significantly (quadratic P<0.001) as well as F:G (quadratic P<0.001). However, in overall (d 0 to 41) growth performance only ADG improved (quadratic P<.001). Average daily feed intake appeared to be a contributing factor in growth performance for all stages of growth. Cracked corn was added to a concentrated pellet to evaluate growth performance on broilers and potential cost reductions at the feed manufacturing facility. A linear decrease was observed overall (0 to 41 d) for ADG, ADFI, and F:G (P<0.003, respectively). Gizzard weight and gizzard yield were significantly increased (P<0.043 and P<0.008, respectively) as cracked corn level increased.
34

Construction of uniform designs and usefulness of uniformity in fractional factorial designs

Qin, Hong 01 January 2002 (has links)
No description available.
35

Statistical Test for Multi-dimensional Uniformity

Hu, Tieyong 10 November 2011 (has links)
Testing uniformity in the univariate case has been studied by many researchers. Many papers have been published on this issue, whereas the multi-dimensional uniformity test seems to have received less attention in the literature. A new test statistic for the multi-dimensional uniformity is proposed in this thesis. The proposed test statistic can be used to test whether an underlying multivariate probability distribution differs from a multi-dimensional uniform distribution. Some important properties of the proposed test statistic are discussed. As a special case, the bivariate test statistic is discussed in detail and the critical values of test statistic are obtained. By performing Monte Carlo simulation, the power of the new test is compared with the Distance to Boundary test, which was a recently proposed statistical test for multi-dimensional uniformity by Berrendero, Cuevas and Vazquez-Grande (2006). It has been shown that the test proposed in this thesis is more powerful than the Distance to Boundary test in some cases.
36

Odezva kalorimetru Tilecal na miony / Odezva kalorimetru Tilecal na miony

Javůrek, Tomáš January 2012 (has links)
Title: Tile Calorimeter response to muons Author: Tomas Javurek Department: Institute of Particle and Nuclear Physics Supervisor: RNDr. Tomas Davidek, Ph.D. Supervisors e-mail address: davidek@ipnp.troja.mff.cuni.cz Abstract: The aim of present work is investigation of Tile calorimeter (subde- tector of ATLAS experiment) response to muons. Muons can help to monitor spatial non-linearities in this hadronic detector. Graphs of unifromities are used for these purposes i.e. dependence of dE/dx (deposited energy per unit length) on azimuthal angle φ and polar angle θ which is represented by pseu- dorapidity η. Finally the dependence of dE/dx on energy was also studied. Keywords: TileCal, muon, uniformity, energy loss
37

An Assessment of the Greatest Impacts on Distribution Uniformity for Drip and Micro Irrigation

Worden, Brooke Ashley 01 September 2018 (has links)
Using the Cal Poly Irrigation Training and Research Centers (ITRC) drip/micro evaluation program, global, or system, DUlq is computed by combining the component DUlq values of: pressure variation, uneven spacing between emitters, unequal drainage and “other” causes. “Other” causes include plugging, wear and manufacturing coefficient. The program also computes what percentage of the non-uniformity is due to each component. Burt (2004) showed that over 95% of the non-uniformity is due to “Other” causes and pressure differences. This thesis looks at what specifically in those components is driving the non-uniformity by analyzing various equipment and field practices and their impact on the distribution uniformity. A regression analysis is used to analyze trends in distribution uniformity in an open environment. The results indicate that more information, specifically water quality, is needed to better analyze which components influence the distribution uniformity of a system.
38

Optimal cleaning strategy of large-scale solar PV arrays considering non-uniform dust deposition

Simiyu, Donah Sheila Nasipwondi January 2020 (has links)
The use of solar photovoltaic systems has increased in the past years in an effort to move towards cleaner energy sources. Solar panels are however affected by negative factors such as dust deposition which hinder their performance. The negative effects that dust deposition has on solar panels depend on how much dust gets deposited on solar panels and how it spreads on the top surface. The spread of dust on solar panels can be uniform where all the solar panels in a entire solar photovoltaic array have the same amount of dust deposition. This is an ideal case and can be defined as uniform dust deposition. However, in real life operation, the spread of dust deposition can vary with one solar panel having a different quantity of dust deposition from another. This is defined as non-uniform dust deposition. Non-uniform dust deposition negatively affects the performance of solar panels by reducing the irradiance that reaches the solar cells thereby reducing the performance of the solar panels. The negative effects of non-uniform dust deposition are more significant over time and when there is no intervention to remove the dust. In practice, the negative effects of non-uniform dust deposition on photovoltaic modules has been addressed by periodically cleaning their top surfaces. Periodic cleaning can however increase the operational costs in terms of the cleaning frequency, time taken, cost of cleaning resources and effectiveness. In this study, we propose an optimal cleaning strategy for the solar power plants that are prone to the non-uniform dust deposition. To develop the optimal cleaning strategy, we first investigate the dust deposition process and develop a model to describe the relationship between the solar power generation and non-uniform dust deposition patterns. Then we formulate an optimization model to identify the most cost-effective solar panel cleaning plan. In the optimisation, the additional revenue due to cleaning the solar panels is formulated as the objective function. The decision variables are the number of photovoltaic strings cleaned at each cleaning interval. To highlight the effectiveness of the proposed solar panels cleaning strategy, the developed cleaning strategy is applied to a case study where analysis of the performances of other solar panel cleaning strategies, namely “full cleaning”, “no cleaning” and “random cleaning” is done. The results from the study show that the optimal cleaning strategy outperforms all the other cleaning strategies showing its effectiveness. The optimal cleaning strategy developed is useful to solar photovoltaic plants owners whose plants are located in dusty or polluted areas. It first provides them with an understanding of non-uniform dust deposition. It also provides a way of reducing the effects of non-uniform dust deposition through optimized cleaning which is cost effective and that allows the photovoltaic array to continuously give the desired output. / Dissertation (MEng)--University of Pretoria, 2020. / Electrical, Electronic and Computer Engineering / MEng / Unrestricted
39

Wasteland: An Investigation on Waste Mitigation in "Cookie-Cutter" Suburbia

Ousley, Drew 25 May 2023 (has links)
No description available.
40

Model za kontrolu površinske uniformnosti digitalnih otisaka / Print uniformity model for digital prints

Jurič Ivana 25 May 2018 (has links)
<p>Površinska uniformnost je jedan od ključnih parametara za analizu<br />kvaliteta otisaka. Osnovni cilj istraživanja je definisanje modela<br />za kvantifikaciju površinske uniformnosti digitalno štampanih<br />otisaka. U nizu sprovedenih eksperimenata procenjen je uticaj ulaznog<br />uređaja za digitalizaciju otisaka i uticaj varijabilnih podešavanja<br />prilikom digitalizacije. U disertaciji su ispitane četiri metode za<br />merenje površinske uniformnosti koje su najčešće korišćene u<br />dosadašnjoj literaturi &ndash; GLCM, ISO 13660, Integralna i M-Score<br />metoda. Na osnovu dobijenih rezultata i zaključaka istraživanja<br />moguće je predložiti razvoj industrijski primenljivog rešenja za<br />merenje površinske uniformnosti digitalno štampanih otisaka.</p> / <p>Print uniformity is one of the key parameters for the analysis of print<br />quality.The basic aim of the research is to define a model for the<br />quantification of print uniformity of digitally printed samples. In the series of<br />carried out experiments, the influence of the input device for digitalisation of<br />prints and the influence of variable settings during digitization was evaluated.<br />The dissertation examined four methods for measuring the surface uniformity<br />most commonly used in the previous literature - GLCM, ISO 13660, Integral<br />and M-Score method. On the basis of the obtained results and conclusions of<br />the research, it is possible to propose the development of an industrially<br />applicable solution for measuring the surface uniformity of digitally printed<br />prints.</p>

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