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Chandler, I. D. "Vertical variation in diffusion coefficient within sediments." Thesis, University of Warwick, 2012. http://wrap.warwick.ac.uk/49612/.
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River ecosystems can be strongly in uenced by contaminants in the water column, in the pore water and attached to sediment particles. Current models [TGD, 2003] predict exposure to sediments based on equilibrium partitioning between dissolved and suspended-particle-sorbed phase in the water column despite numerous studies showing significant direct mass transfer across the sediment water interface. When exchange across the interface (hyporheic exchange) is included in modelling the diffusion coefficient is assumed to be constant with depth. The overall aims of this research were to quantify the vertical variation in diffusion coefficient below the sediment water interface and asses the use of a modified EROSIMESS-System (erosimeter) in the study of hyporheic exchange. The modified erosimeter and novel fibre optic uorometers measuring in-bed concentrations Rhodamine WT were employed in an experimental investigation. Five different diameter glass sphere beds (0.15 to 5.0mm) and five bed shear velocities (0.01 to 0.04m/s) allowed the vertical variation in diffusion coefficient to be quantified to a depth of 0.134m below the sediment water interface. The vertical variation in diffusion coefficient can be described using an exponential function that was found to be consistent for all the parameter combinations tested. This function, combined with the scaling relationship proposed by O'Connor and Harvey [2008] allows a prediction of the diffusion coefficient below the sediment water interface based on bed shear velocity, roughness height and permeability. 1D numerical diffusion model simulations using the exponential function compare favourably with the experimental data.
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曾達誠 and Tat-shing Tsang. "Statistical inference on the coefficient of variation." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2000. http://hub.hku.hk/bib/B31223503.
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Tsang, Tat-shing. "Statistical inference on the coefficient of variation /." Hong Kong : University of Hong Kong, 2000. http://sunzi.lib.hku.hk/hkuto/record.jsp?B21903980.
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Achouri, Ali. "Cartes de contrôle pour le coefficient de variation." Nantes, 2014. http://archive.bu.univ-nantes.fr/pollux/show.action?id=7658d471-1a91-4022-9493-9f85b2a06a86.
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La Maîtrise Statistique des Procédés (MSP) est une méthode de suivi de la production basée sur les statistiques. Elle se base essentiellement sur les cartes de contrôle. Une hypothèse indispensable pour le développement des cartes de contrôle est que les paramètres μ0 et 0 du procédé sous-contrôle soient supposés constants. Mais, dans la pratique, il existe de nombreux procédés pour lesquels ces paramètres peuvent être variables. Dans cette optique, le recours au coefficient de variation est une alternative intéressante. Dans cette thèse, nous avons essayé de systématiquement proposer de nouvelles cartes de contrôle pour le coefficient de variation qui n’ont pas encore été traitées jusqu’à présent dans la littérature. Des cartes de contrôle avec règles supplémentaires, des cartes VSI, VSS sont proposées pour le coefficient de variation lorsque les paramètres sont connus. De plus, une carte de type Shewhart pour le coefficient de variation avec paramètres estimés est aussi proposée. Les performances de chacune des cartes ont été évaluées et les paramètres optimaux ont été systématiquement calculés. Une validation empirique des résultats a été élaborée dans des processus industriels existantsThe Statistical Process Control (SPC) is an effective method based on statistics and used to monitor production. Control charts are the most important and primary tools of SPC. An indispensable assumption for the development of control charts is that the process parameters μ0 and 0 are assumed constant. In practice, the process parameters are often variables and the use of the coefficient of variation seems to be an interesting alternative. In this thesis, we will investigate the properties (in terms of the Run Length) of some control charts for the coefficient of variation in the case of known parameters, which have not been researched till now, such as Run Rules Chart, VSI Chart and VSS Chart. In addition, a Shewhart control chart for the coefficient of variation with estimated parameters is proposed. The performance of each control chart has been evaluated and the optimal parameters were systematically computed. An empirical validation of the results has been developed for real industrial processes
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Byars, Beverly J. "Variation of the drag coefficient with wind and wave state." Thesis, Monterey, Calif. : Naval Postgraduate School, 1985. http://catalog.hathitrust.org/api/volumes/oclc/52763691.html.
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Amdouni, Asma. "Surveillance statistique du coefficient de variation dans un contexte de petites séries." Nantes, 2015. http://archive.bu.univ-nantes.fr/pollux/show.action?id=dcf36868-32b2-41d6-916b-f9533ee12902.
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La maîtrise statistique des procédés (MSP) est une méthode de contrôle de la qualité basée sur les statistiques. La surveillance du coefficient de variation est une approche efficace à la MSP lorsque la moyenne du processus µ et son écart type σ ne sont pas constants mais leur rapport est constant. Jusqu’à présent, les études portant sur la surveillance du coefficient de variation se sont limitées au cas d’une production avec un horizon infini. Cette thèse présente de nouvelles cartes de contrôle pour surveiller le coefficient de variation dans le contexte fini lorsque les paramètres sont connus : des cartes de contrôle séparées de type Shewhart, des cartes avec des règles supplémentaires et des cartes VSI et VSS. Les paramètres optimaux ont été systématiquement calculés et les performances de chacune de ces cartes ont été également évaluées en développant de nouvelles mesures statistique de performance appropriées dans un contexte de production à horizon fini. Une validation empirique des résultats a été élaborée pour des procédés industriels existantsStatistical Process Control (SPC) is a method of quality control based on statistics and used to monitor production. Monitoring the coefficient of variation is an effective approach to SPC when the process mean µ and standard deviation σ are not constant but their ratio is constant. Until now, research has not investigated the monitoring of the coefficient of variation for short production runs. Viewed under this perspective, in this thesis, we will propose new methods to monitor the coefficient of variation for a finite horizon production, we will investigate the properties (in terms of the Truncated Run Length) of some control charts for the coefficient of variation in a Short Run context in the case of known parameters, such as the one-sided Shewhart Chart, the Run Rules Chart, the VSI and VSS Charts. The performance of each control chart has been evaluated by developing statistical measures of performance appropriate in a Short Run context and the optimal parameters were systematically computed. An empirical validation of the results has been developed for real industrial processes
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Beale, James H. "Internal flow subjected to an axial variation of the external heat transfer coefficient." Thesis, Virginia Polytechnic Institute and State University, 1987. http://hdl.handle.net/10919/91162.
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A theoretical investigation of internal flow subjected to an axial variation of the external convection coefficient is presented. Since the variable boundary condition parameter causes the problem to become nonseparable, conventional techniques do not apply. Instead, the Green's function technique is used to convert the governing partial differential equations into a singular Volterra integral equation for the temperature of the fluid at the wall. The integral equation is resolved numerically by the trapezoid rule with the aid of a singularity subtraction procedure. The solution methodology is developed in terms of a fully turbulent flow which is shown to contain fully laminar and slug flow as special cases.
Before examining the results generated by numerical solution of the integral equation, a thorough study is made of each of the building blocks required in the solution procedure. A comparison of the respective dimensionless velocity profiles and dimensionless total diffusivities for each of the flow models is presented. Next, an analysis of the eigenvalue problem for each flow model is presented with consideration given to the normalized eigenfunctions and the eigenvalues themselves. Finally, the singular nature of the Green's function is examined showing the effect of the parameters Ho, Re and Pr.
The technique is applied to study the heat transfer from a finned tube. A parameter study is presented to examine the effects of the external finning and the flow model. The effect of external finning is examined through specific variations of the external convection coefficient, while the flow model is selected through the velocity profile and eddy diffusivity. In examining turbulent flow, the effects of the parameters, Re and Pr, are considered.M.S.
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Archer, Robert Joseph 1957. "Effects of spacial variation of the thermal coefficient of expansion on optical surfaces." Thesis, The University of Arizona, 1988. http://hdl.handle.net/10150/276887.
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The deformation of a mirror's optical surface due to a spacial variation of the coefficient of thermal expansion is examined. Four types of variations of the coefficient of thermal expansion are studied. These represent variations which result after typical manufacturing and/or fabrication processes. Equations describing the deformations resulting from the variations in the coefficient of thermal expansion are derived for some of the cases. Deformations due to more complex variations in the coefficient of thermal expansion are developed empirically using data generated by the finite-element method.
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Fike, Gregory Michael. "Using Infrared Thermography to Image the Drying of Polymer Surfaces." Thesis, Georgia Institute of Technology, 2004. http://hdl.handle.net/1853/4808.
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During the drying of a surface, the liquid evaporation acts to keep the temperature relatively constant, due to evaporative cooling. As the drying nears completion the liquid film begins to break, exposing areas that are no longer cooled through evaporation, which begin to heat. Although this heating can be measured with an Infrared (IR) camera, the sensitivity is often not sufficient to recognize the point at which the film breaks. Complicating the measurement is the changing emissivity that commonly occurs as objects dry.
The sensitivity and emissivity issues can be addressed by analyzing the temperature in the area of interest and computing the coefficient of variance (COV) of the temperature. This technique is compared to temperature and standard deviation measurements made with an IR camera and the COV technique is shown to be superior for determining when the liquid film breaks. The film breakage point is found to vary with temperature and material roughness in two industrially significant applications: the drying of wood flakes and the drying of polymer films.
Film breakage in wood flakes is related to detrimental finished quality problems and also to emission problems. The rate at which an adhesive dries affects the roughness of the polymer film and subsequently, the bond strength. The COV technique is used to predict the roughness of the finished polymer film. Use of the COV technique allows the drying of a liquid film to be visualized in a way that has been previously unreported.
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Kane, David Alan. "Penetration Depth Variation in Atomic Layer Deposition on Multiwalled Carbon Nanotube Forests." BYU ScholarsArchive, 2018. https://scholarsarchive.byu.edu/etd/7124.
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Atomic Layer Deposition (ALD) of Al2O3 on tall multiwalled carbon nanotube forests shows concentration variation with the depth in the form of discrete steps. While ALD is capable of extremely conformal deposition in high aspect ratio structures, decreasing penetration depth has been observed over multiple thermal ALD cycles on 1.3 mm tall multiwalled carbon nanotube forests. SEM imaging with Energy Dispersive X-ray Spectroscopy elemental analysis shows steps of decreasing intensity corresponding to decreasing concentrations of Al2O3. A study of these steps suggests that they are produced by a combination of diffusion limited delivery of precursors with increasing precursor adsorption site density as discrete nuclei grow during the ALD process. This conceptual model has been applied to modify literature models for ALD penetration on high aspect ratio structures, allowing several parameters to be extracted from the experimental data. The Knudsen diffusion constant for trimethylaluminum (TMA) in these carbon nanotube forests has been found to be 0.3 cm2s-1. From the profile of the Al2O3 concentration at the steps, the sticking coefficient of TMA on Al2O3 was found to be 0.003.
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Devkota, Jay P. "Variation of Manning’s Roughness Coefficient with Diameter, Discharge, Slope and Depth in Partially Filled HDPE Culverts." Youngstown State University / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1340991250.
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Amiri, Saeid. "On the Application of the Bootstrap : Coefficient of Variation, Contingency Table, Information Theory and Ranked Set Sampling." Doctoral thesis, Uppsala universitet, Matematiska institutionen, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-159206.
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This thesis deals with the bootstrap method. Three decades after the seminal paper by Bradly Efron, still the horizons of this method need more exploration. The research presented herein has stepped into different fields of statistics where the bootstrap method can be utilized as a fundamental statistical tool in almost any application. The thesis considers various statistical problems, which is explained briefly below. Bootstrap method: A comparison of the parametric and the nonparametric bootstrap of variance is presented. The bootstrap of ranked set sampling is dealt with, as well as the wealth of theories and applications on the RSS bootstrap that exist nowadays. Moreover, the performance of RSS in resampling is explored. Furthermore, the application of the bootstrap method in the inference of contingency table test is studied. Coefficient of variation: This part shows the capacity of the bootstrap for inferring the coefficient of variation, a task which the asymptotic method does not perform very well. Information theory: There are few works on the study of information theory, especially on the inference of entropy. The papers included in this thesis try to achieve the inference of entropy using the bootstrap method.
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Hanegan, Andrew Aaron. "Industrial energy use indices." Texas A&M University, 2007. http://hdl.handle.net/1969.1/85849.
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Energy use index (EUI) is an important measure of energy use which normalizes
energy use by dividing by building area. Energy use indices and associated coefficients
of variation are computed for major industry categories for electricity and natural gas use
in small and medium-sized plants in the U.S. The data is very scattered with the
coefficients of variation (CoV) often exceeding the average EUI for an energy type. The
combined CoV from all of the industries considered, which accounts for 8,200 plants
from all areas of the continental U.S., is 290%. This paper discusses EUIs and their
variations based on electricity and natural gas consumption. Data from milder climates
appears more scattered than that from colder climates. For example, the ratio of the
average of coefficient of variations for all industry types in warm versus cold regions of
the U.S. varies from 1.1 to 1.7 depending on the energy sources considered.
The large data scatter indicates that predictions of energy use obtained by
multiplying standard EUI data by plant area may be inaccurate and are less accurate in
warmer than colder climates (warmer and colder are determined by annual average
temperature weather data). Data scatter may have several explanations, including
climate, plant area accounting, the influence of low cost energy and low cost buildings
used in the south of the U.S. This analysis uses electricity and natural gas energy consumption and area data of
manufacturing plants available in the U.S. Department of Energy's national Industrial
Assessment Center (IAC) database. The data there come from Industrial Assessment
Centers which employ university engineering students, faculty and staff to perform
energy assessments for small to medium-sized manufacturing plants. The nation-wide
IAC program is sponsored by the U.S. Department of Energy.
A collection of six general energy saving recommendations were also written with
Texas manufacturing plants in mind. These are meant to provide an easily accessible
starting point for facilities that wish to reduce costs and energy consumption, and are
based on common recommendations from the Texas A&M University IAC program.
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Patterson, Mason Foushee. "Standardization of Street Sampling Units to Improve Street Tree Population Estimates Derived by I-Tree Streets Inventory Software." Thesis, Virginia Tech, 2012. http://hdl.handle.net/10919/42687.
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Street trees are a subpopulation of the urban forest resource and exist in the rights-of-way adjacent to public roads in a municipality. Benefit-cost analyses have shown that the annual benefits provided by the average street tree far outweigh the costs of planting and maintenance. City and municipal foresters spend a majority of their time and resources managing street tree populations. Sample street tree inventories are a common method of estimating municipal street tree populations for the purposes of making urban forest policy, planning, and management decisions.
i-Tree Streets is a suite of software tools capable of producing estimates of street tree abundance and value from a sample of street trees taken along randomly selected sections (segments) of public streets. During sample street tree inventories conducted by Virginia Tech Urban Forestry, it was observed that the lengths of the sample streets recommended by i-Tree varied greatly within most municipalities leading to concern about the impact of street length variation on sampling precision.
This project was conducted to improve i-Tree Streets by changing the recommended sampling protocol without altering the software. Complete street tree censuses were obtained from 7 localities and standardized using GIS. The effects of standardizing street
segments to 3 different lengths prior to sampling on the accuracy and precision of i-Tree Streets estimates were investigated though computer simulations and analysis of changes in variation in number of trees per street segment as a basis for recommending procedural changes.
It was found that standardizing street segments significantly improved the precision of i-Tree Streets estimates. Based on the results of this investigation, it is generally recommended that street segments be standardized to 91m (300 ft) prior to conducting a sample inventory. Standardizing to 91m will significantly reduce the number of trees, the number of street segments, and the percentage of total street segments that must be sampled to achieve an estimate with a 10% relative standard error.
The effectiveness of standardization and the associated processing time can be computed from municipal attributes before standardization so practitioners can gauge the marginal gains in field time versus costs in processing time. Automating standardization procedures or conducting an optimization study of segment length would continue to increase the efficiency and marginal gains associated with street segment standardization.Master of Science
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Brown, Andrew Gavin. "Measurement and modelling of combustion in a spark ignition engine." Thesis, Brunel University, 1991. http://bura.brunel.ac.uk/handle/2438/5143.
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A study has been conducted into the causes of cycle by cycle variations in combustion within a spark ignition engine, the best measured engine parameter to use for its characterization, and the effects that: ignition timing, equivalence ratio, fuel type, throttle position and knock, have upon it. A Ricardo E6 single cylinder variable compression ratio research engine was instrumented to allow measurement of: cylinder pressure, temperatures, speed, load, fuel flow and air flow. The engine was also fitted with an optical slice that allowed optical access to the combustion chamber and enabled measurement of the early flame speed (up to 10 mm from spark plug gap) using a laser schileren system. Cylinder pressure data were collected on a dedicated HP1000 computer for every degree of crank angle rotation for up to 300 successive cycles. A phenomenological model was developed for turbulent combustion that split the combustion process into three phases: early laminar burn, turbulent combustion, and final burn. The model allowed the study of the physical phenomena occurring within the combustion chamber and enabled insights to be gained into their effects on combustion and cyclic variations. The study showed: The variation in mixture strength has a far greater effect on the average and Coefficient of Variation (COV) values of all the combustion performance parameters, than does changing the fuel type. Cycle by cycle variations in combustion are best characterized by COV of imep. The onset of knock has no discernible effect on the COVs of the measured parameters. The part throttle results show higher COVs than at Wide Open Throttle (WOT) due to slower burn, supporting the theory that faster initial flame speeds reduce cyclic variations. The combustion model was used to support the hypothesis that cycle by cycle variations are caused by movement of the flame kernel by turbulence within the combustion chamber.
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Ribeiro, Pedro de Assunção Pimenta. "Avaliação das medidas de dispersão na pesquisa avícola." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/10/10135/tde-28112014-134301/.
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Há pouca literatura acerca dos valores de referência das medidas de dispersão na pesquisa avícola bem como a relação entre tais medidas e o número de aves por repetição e número de repetições e ainda os efeitos de fatores intrínsecos à pesquisa sobre a variabilidade experimental. Com isso, objetiva-se estabelecer faixas de classificação das medidas de dispersão, bem como a relação entre medidas e o número de aves por repetição, número de repetições por tratamento, número de aves abatidas para avaliação de carcaças, número de ovos coletados para análises de qualidade e os efeitos de fatores intrínsecos à pesquisa sobre a variabilidade experimental. Os dados foram obtidos nos trabalhos publicados nos periódicos com classificação Qualis/CAPES nos estratos A1, A2, B1, B2 e B3, na área de zootecnia. Para a determinação das faixas de classificação das medidas de dispersão. Os dados foram correlacionados através da correlação de Spearman, dados qualitativos foram comparados pelo teste de Kruskal-Wallis. As faixas de classificação de coeficientes de variação podem ser utilizadas como balizador da qualidade e confiabilidade dos dados de experimentos com poedeiras comerciais e frangos de corte. A fase de vida ou estágio produtivo de poedeiras e frangos de corte devem ser levados em consideração na comparação de resultados experimentais. O erro padrão da média varia bastante nos parâmetros produtivos de poedeiras e frangos de corte e parece não ser uma medida de dispersão indicada para se comparar a precisão de diferentes experimentos, as suas faixas de classificação servem como referencial da frequência com que se encontra resultados. Coeficientes de variação e erros padrão da média de parâmetros produtivos de frangos de corte e de poedeiras comerciais são menores quanto maior o número de repetições e de aves por repetição. As aves amostradas para o abate nas avaliações de carcaça de frangos de corte devem apresentar o peso médio da parcela. O número de aves amostradas não influencia a variabilidade experimental. Os dias de amostragem para análises de qualidade de ovos não influenciam a variação aleatória. O número ideal de ovos amostrados está entre quatro e cinco ovos por repetição. Em frangos de corte a variabilidade aleatória para variáveis de produção são maiores para aves da linhagem Ross do que para aves da linhagem Cobb. Lotes mistos de frangos de corte apresentam maior variação de ganho de peso do que lotes de machos na fase de criação de um a 21 dias de idade. O rendimento de carcaça e a porcentagem de gordura abdominal apresentam menor variabilidade aleatória em lotes mistos do que em lotes de frangos machos. Para frangos de corte não há efeitos aleatórios que possam aumentar a variabilidade experimental em função da área disponível por ave. Para poedeiras quanto maior o período experimental menor tende a ser a variação aleatória. Poedeiras brancas apresentam menor variação aleatória dos parâmetros produtivos do que poedeiras vermelhas. O coeficiente de variação de parâmetros produtivos de poedeiras comerciais aumenta com o aumento da área disponível por ave.There is little literature on the reference values of spread measures in poultry research and the relationship between such measures and the number of birds per replicate and number of replicates and even the effects of intrinsic factors to research on experimental variability. The aim of this research is to establish ranges for the classification of spread measures, and the relationship between measurements and the number of birds per replicate, number of replicates per treatment, number of birds slaughtered for carcass evaluation, number of eggs collected for quality analysis and impact of research intrinsic factors on experimental variability. The data were obtained in papers published in journals with Qualis/CAPES classification in strata A1, A2, B1, B2 and B3, in the area of animal science. To determine the classification of the spread measures. The data were correlated by Spearman correlation, qualitative data were compared using the Kruskal-Wallis test. The classification ranges of coefficients of variation can be used as an indicator of the quality and reliability of data from experiments with laying hens and broilers. The age or production stage of laying hens and broilers should be considered in the comparison of experimental results. The standard error of means varies greatly in production parameters of laying hens and broilers and seems not to be a measure of dispersion indicated to compare the accuracy of different experiments, their classification ranges serve as a frequency reference which it is results. Coefficients of variation and standard error of means of production parameters of broilers and laying hens are smaller the greater the number of repetitions and birds per replicate. The birds sampled for slaughter in assessing carcass of broilers must present the average weight of the replicate. The number of birds sampled does not influence the experimental variability. The days of sampling for quality analysis of eggs did not influence the random variation. The ideal number of eggs sampled is between four and five eggs per replicate. In broilers random variability for production variables are higher for Ross than for Cobb broilers. Straight run broilers exhibit greater variation in weight gain than lots of males in the creation phase of 1 to 21 days old. The carcass yield and abdominal fat have less random variability in straight run broilers than in lots of male chickens. No random effects that can increase experimental variability depending on the available area per bird on broilers. The higher is experimental period the greater is the random variations. White hens have less random variation in production parameters than brown hens. The coefficient of variation of productive parameters of laying hens increases with increasing the available area per bird.
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Ezhilan, Madhumitha. "Commissioning a Commercial Laser Induced Fluorescence System for Characterization of Static Mixer Performance." University of Dayton / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1499793560290147.
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Limaux, François. "Facteurs de variation du coefficient apparent d'utilisation de l'azote de l'engrais : conséquences pour la conduite de la fertilisation azotée du blé d'hiver en Lorraine." Vandoeuvre-les-Nancy, INPL, 1994. http://docnum.univ-lorraine.fr/public/INPL_T_1994_LIMAUX_F.pdf.
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Une écriture simplifiée du bilan azoté pour la culture du blé d'hiver a été proposé en région Lorraine. Deux années d'expérimentation avec l'isotope 15N ont permis de justifier certains termes de ce bilan simplifié en confirmant, en particulier, l'indépendance des fournitures en azote du sol, par rapport à la dose apportée. Les conditions de variation du coefficient apparent d'utilisation (CAU) de l'azote de l'engrais ont été étudiées, notamment en fonction du temps de présence de l'engrais dans le sol. Par ailleurs, les résultats acquis suggèrent que le CAU est dépendant de la biomasse élaborée au moment des apports d'azote, donc des capacités d'absorption du peuplement. On propose en conclusion de tester une méthodologie opérationnelle des apports d'azote qui prenne en compte, non seulement le stade phrénologique, mais également l'état de croissance du peuplement
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Hachuy, Leandro 1959. "Desempenho de uma distribuidora a lanço com dois tipos de produtos aplicados em diferentes posições de aletas nos discos /." Botucatu : [s.n.], 2008. http://hdl.handle.net/11449/90642.
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Resumo: Dentre as operações preliminares para a boa condução de uma cultura instalada a campo está a calagem, que visa corrigir as propriedades químicas do solo e também a adubação a lanço com nitrogênio, tradicionalmente utilizada em cobertura, e hoje numa nova tendência, em pré-plantio. Não se tem domínio ou informações confiáveis sobre a maioria das máquinas disponíveis no mercado brasileiro referentes à qualidade da aplicação realizada por esses equipamentos, bem como a sua largura efetiva de trabalho. Essa largura é determinada como função de uma regularidade mínima na dosagem, obtida a partir da sobreposição com passadas adjacentes. A determinação da largura de trabalho ou largura efetiva é definida a partir de ensaios padronizados. O experimento foi conduzido a campo, no ano de 2008, na Fazenda Experimental Lageado da Faculdade de Ciências Agronômicas - Unesp- Campus de Botucatu SP, em solo classificado como Nitossolo Vermelho distroférrico.O presente trabalho teve como objetivo principal avaliar o desempenho de um distribuidor a lanço na aplicação de calcário e uréia com 4 diferentes posições de aletas nos discos em uma mesma velocidade de deslocamento do trator. Os tratamentos foram os seguintes: T1- calcário - largura de distribuição média e direcionamento do produto intermediário; T2- calcário - largura de distribuição menor e direcionamento do produto mais para o centro; T3- calcário - largura de distribuição maior e direcionamento do produto mais para as extremidades; T4- calcário - ajuste de somente duas aletas em ângulos diferentes das demais; T5- uréia - ajuste de somente duas aletas em ângulos diferentes das demais; T6- uréia - largura de distribuição média e direcionamento do produto intermediário; T7- uréia - largura de distribuição menor e direcionamento do produto mais para o centro;... (Resumo completo, clicar acesso eletrônico abaixo)Abstract: Among the preliminary to the smooth conduct of a culture installed the field is set, seeking to correct the chemical properties of soil and and also the fertilizing to throw, traditionally used in covering, and today in a new tendency, in daily pre-planting. There is no field or reliable information on the majority of machines available in the Brazilian market concerning the quality of the application made by such equipment as well as its effective width of work. This width is determined as a function of the regular minimum strength, obtained from the overlap with adjacent past. The determination of the width of work or effective width is defined from standardized tests. Liming, in most cases is done with machines called specialized applications of fertilizers and corrective. The machines are divided as the mechanism doser in centrifugal and continuous thread. Quantities ideals are obtained through specific formulas. The experiment was carried out in 2008, on the the Experimental Farm Lageado of São Paulo State University in Botucatu, on soil classified as Dystroferric Red Nitosol.This study aimed to evaluate the performance of primary distributor with a haul in the application of lime and urea with 4 different positions of fins on the disks in the same speed of displacement of the tractor. The treatments were: T1-lime - average width of distribution and product direction of the intermediary, T2-lime - width of distribution and lower direction of the product more to the center; T3-lime - width and direction of greater distribution of the product more to the extremities; T4-lime - adjustment of only two fins at different angles of the other; T5-urea - adjustment of only two fins at different angles of the other; T6-urea - average width of distribution and product direction of the intermediary; T7 -urea - width of distribution and lower direction of the product more to the center;... (Complete abstract click electronic access below)
Orientador: Sérgio Hugo Benez
Coorientador: Paulo Roberto Arbex Silva
Banca: Silvio José Bicudo
Banca: Elcio Hiroyoshi Yano
Mestre
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Ali-Adib, Tarif. "Estimation et lois de variation du coefficient de transfert de chaleur surface/ liquide en ébullition pour un liquide alimentaire dans un évaporateur à flot tombant." Phd thesis, AgroParisTech, 2008. http://pastel.archives-ouvertes.fr/pastel-00004544.
Full textAbstract:
Le coefficient de transfert de chaleur est nécessaire pour concevoir et dimensionner un évaporateur utilisé pour concentrer un liquide, tel que rencontré couramment dans les industries alimentaires. Le coefficient de transfert de chaleur le plus variable et le plus incertain est du coté produit, entre paroi et liquide, noté « h ». Il varie à la fois avec les propriétés thermo-physiques du liquide traité (ηL, σL, λL, ρL , CpL, ω, ...) et avec les paramètres du procédé (type d'évaporateur, φ ou Δθ, Γ (δ), P, rugosité de la surface, encrassement, etc), ces grandeurs étant définies dans le texte. Mais h est aussi lié au régime d'ébullition (nucléée ou non nucléée), et pour les évaporateurs de type « flot tombant », au régime d'écoulement laminaire ou turbulent, selon le nombre de Reynolds en film Ref. Nous avons étudié le cas des évaporateurs « à flot tombant », très utilisés dans les industries alimentaires pour concentrer le lait et les produits laitiers, les jus sucrés, les jus de fruits et légumes. L'objectif de notre travail était de définir une méthode fiable et économique pour évaluer a priori le coefficient de transfert de chaleur h coté liquide en ébullition, dans un évaporateur flot tombant. La première partie de la thèse a été consacrée à l'analyse bibliographique, qui a révélé une grande incertitude actuelle dans la prévision de h, sur la base des formules de la littérature, et des paramètres descripteurs proposés. La deuxième partie de la thèse a été de concevoir et construire un pilote utilisable pour estimer h, dans des conditions stationnaires connues et reproductibles. Dans la troisième partie, on présente les résultats et commente les lois de variations de h en fonction de la concentration de matière sèche du liquide XMS, de la température d'ébullition de liquide θL (ou P), du flux de chaleur φ ou (Δθ), et du débit massique de liquide par unité de périmètre de tube Γ, pour des propriétés de surface de chauffe fixées (ici, paroi en acier inoxydable poli Rs ≈ 0,8 μm). On commente l'effet sur h de chaque variable isolément, les autres étant maintenues constantes, ce qui confirme l'importance de la transition du régime non-nucléé au régime nucléé, cette transition variant avec la nature du liquide, sa concentration, et le flux de chaleur. On a montré la possibilité de modéliser un produit donné dans l'ensemble du domaine expérimental, où tous les paramètres peuvent varier simultanément, avec peu de coefficients, selon deux types d'équations (polynomiale et puissance). On a comparé le cas d'un liquide Newtonien (jus sucré) et non-Newtonien (solution de CMC dans l'eau). On a aussi observé le débit de mouillage critique Γcri et ses lois de variation. On a aussi démontré la possibilité de simplifier le plan d'expérience, aussi bien pour les liquides Newtoniens que non-Newtoniens, tout en gardant un coefficient de corrélation satisfaisant dans le domaine Γ > Γcri, cette modélisation pouvant servir de base de données produit pour l'ingénierie.
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Ali, Adib Tarif. "Estimation et lois de variation du coefficient de transfert de chaleur surface / liquide en ébullition pour un liquide alimentaire dans un évaporateur à flot tombant." Paris, AgroParisTech, 2008. http://pastel.paristech.org/4544/01/2008AGPT0007.pdf.
Full textAbstract:
Le coefficient de transfert de chaleur est nécessaire pour concevoir et dimensionner un évaporateur utilisé pour concentrer un liquide, tel que rencontré couramment dans les industries alimentaires. Le coefficient de transfert de chaleur le plus variable et le plus incertain est du côté produit, entre paroi et liquide, noté « h ». Il varie à la fois avec les propriétés thermo-physiques du liquide traité (ηL, σL, λL, ρL, CpL, ω,. . . ) et avec les paramètres du procédés (type d’évaporateur, φ ou Δθ, Γ (δ), P, rugosité de la surface, encrassement, etc), ces grandeurs étant définies dans le texte. Mais h est aussi lié au régime d’ébullition (nucléée ou non nucléée), et pour les évaporateurs de type « flot tombant », au régime d’écoulement laminaire ou turbulent, selon le nombre de Reynolds en film Ref. Nous avons étudié le cas des évaporateurs « à flot tombant », très utilisés dans les industries alimentaires pour concentrer le lait et les produits laitiers, les jus sucrés, les jus de fruits et légumes. L’objectif de notre travail était de définir une méthode fiable et économique pour évaluer a priori le coefficient de transfert de chaleur h côté liquide en ébullition dans un évaporateur flot tombant. La première partie de la thèse a été consacrée à l’analyse bibliographique, qui a révélé une grande incertitude actuelle dans la prévision de h, sur la base des formules de la littérature, et des paramètres descripteurs proposés. La deuxième partie de la thèse a été de concevoir et construire un pilote utilisable pour estimer h, dans des conditions stationnaires connues et reproductibles. Dans la troisième partie, on présente les résultats et commente les lois de variations de h en fonction de la concentration de matière sèche du liquide XMS, de la température d’ébullition de liquide θL (ou P), du flux de chaleur φ ou Δθ, et du débit massique de liquide par unité de périmètre de tube Γ, pour des propriétés de surface de chauffe fixées (ici, paroi en acier inoxydable poli Rs≈0,8 μm). On commente l’effet sur h de chaque variable isolément, les autres étant maintenues constantes, ce qui confirme l’importance de la transition du régime non nucléé au régime nucléé, cette transition variant avec la nature du liquide, sa concentration, et le flux de chaleur. On a aussi montré la possibilité de modéliser un produit donné dans l’ensemble du domaine expérimental, où tous les paramètres peuvent varier simultanément, avec peu de coefficients, selon deux types d’équations (polynomiale et puissance). On a comparé le cas d’un liquide Newtonien (jus sucré) et non Newtonien (solution de CMC dans l’eau). On a aussi observé le débit de mouillage critique Γcri et ses lois de variation. On a aussi démontré la possibilité de simplifier le plan d’expérience, aussi bien pour les liquides Newtoniens que non Newtoniens, tout en gardant un coefficient de corrélation satisfaisant le domaine Γ > Γcri, cette modélisation pouvant servir de base de données produit pour l’ingénierieThe heat transfer coefficient value is necessary to calculate the eat exchange surface when designing an evaporator, as currently used to concentrate liquids in food industry. The boiling heat transfer coefficient on the liquid side (h) is the most uncertain and: it depends on the liquid thermo-physical properties (ηL, σL, λL, ρL, CpL, ω,. . . ) as well as on the process conditions (type of evaporator, φ ou Δθ, Γ (δ), P, surface roughness, fouling, etc). Also, h depends on the boiling regime (non-nucleate or nucleate) and on the flow regime (laminar or turbulent) according to the film Reynolds number in falling film evaporators. The objective of our work is to define an economical and robust method to estimate h in a falling film evaporator which is common in food industry for concentrating fruit juice, milk and sugar solutions. The first section of our study was a bibliographic analysis which revealed the important dispersion among the h values calculated from the formulas cited in literature The second section was to design and construct a laboratory scale falling film evaporator (pilot) used to estimate h at stationary parameters conditions. The third section was to describe the results and variation laws of h versus the liquid dry matter concentration XMS, the boiling temperature θL, the heat flux φ or temperature gap Δθ and mass flow rate per unit of perimeter length Γ (with describing the critical mass flow for some solutions) noted that the nature of heating surface is kept constant during our work. We described the effect of each variable separately on h where, the other variables being kept constant. Also we studied the transition from non nucleate regime, which varied with the nature of liquid and the liquid concentration. Finally, we presented the experimental models for h = f (XMS,θL,φ,Γ) for a Newtonian liquid (sugar solution) and non Newtonian solution (CMC) that may be used for industrial evaporator design after validation. We have also proposed a method for the simplification or the experimental design
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Lindemann, Yves. "Contribution à l'étude statistique des répartitions et à la modélisation de la dynamique de l'azote nitrique dans le sol." Paris 11, 1986. http://www.theses.fr/1986PA112364.
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Le coefficient de· variation de la répartition des teneurs en azote nitrique dans le sol est constant : 30 pour cent environ avec un coefficient de corrélation de 0,9. Il est largement plus grand que celui des autres éléments chimiques et physiques du sol. Il en résulte une grande incertitude sur la moyenne des quantités de nitrate mesurées. Les hypothèses de normalité et de lognormalité des échantillonnages sont difficilement acceptables et les conditions de validité de l'analyse de variance ne sont pas respectées. Cette grande hétérogénéité provient des techniques d'épandage des engrais azotés, de la répartition aléatoire de l'activité microbienne et de la faible diffusion des ions nitriques dans la solution du sol. L'ensemble des transferts physiques et biochimiques de l'azote nitrique doit donc être considéré comme de type proportionnel aux quantités présentes. Ce processus est à l'origine de l'évolution vers une dissymétrie gauche des populations. L'utilisation d'azote 15 apporte une meilleure connaissance numérique sur le devenir de l'azote minéral dans le système sol-plante. De nombreux exemples sont donnés pour des cultures de betterave sucrière : coefficient réel d'utilisation, minéralisation et organisation brutes, faible risque de pollution sous couvert végétal. Le bilan des Entrées-Sorties est équilibré sous l'hypothèse du même devenir de l'azote minéralisé et de celui apporté par l'engrais. Il est proposé un modèle compartimental décrivant la dynamique de l'azote minéral en sol nu ou cultivé. Les transferts bruts, ou débits d'échange sont calculés par une intégrale sous hypothèse hyperbolique. Une autre étude du modèle compartimental est effectuée en fonction du temps. La solution proposée est une conséquence directe des conclusions sur l'hétérogénéité des répartitions de l'azote nitrique dans le sol.
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Hachuy, Leandro [UNESP]. "Desempenho de uma distribuidora a lanço com dois tipos de produtos aplicados em diferentes posições de aletas nos discos." Universidade Estadual Paulista (UNESP), 2008. http://hdl.handle.net/11449/90642.
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hachuy_l_me_botfca.pdf: 561032 bytes, checksum: e2112f64e18c75e1470be1df52d15a35 (MD5)Dentre as operações preliminares para a boa condução de uma cultura instalada a campo está a calagem, que visa corrigir as propriedades químicas do solo e também a adubação a lanço com nitrogênio, tradicionalmente utilizada em cobertura, e hoje numa nova tendência, em pré-plantio. Não se tem domínio ou informações confiáveis sobre a maioria das máquinas disponíveis no mercado brasileiro referentes à qualidade da aplicação realizada por esses equipamentos, bem como a sua largura efetiva de trabalho. Essa largura é determinada como função de uma regularidade mínima na dosagem, obtida a partir da sobreposição com passadas adjacentes. A determinação da largura de trabalho ou largura efetiva é definida a partir de ensaios padronizados. O experimento foi conduzido a campo, no ano de 2008, na Fazenda Experimental Lageado da Faculdade de Ciências Agronômicas – Unesp- Campus de Botucatu SP, em solo classificado como Nitossolo Vermelho distroférrico.O presente trabalho teve como objetivo principal avaliar o desempenho de um distribuidor a lanço na aplicação de calcário e uréia com 4 diferentes posições de aletas nos discos em uma mesma velocidade de deslocamento do trator. Os tratamentos foram os seguintes: T1- calcário – largura de distribuição média e direcionamento do produto intermediário; T2- calcário – largura de distribuição menor e direcionamento do produto mais para o centro; T3- calcário – largura de distribuição maior e direcionamento do produto mais para as extremidades; T4- calcário – ajuste de somente duas aletas em ângulos diferentes das demais; T5- uréia – ajuste de somente duas aletas em ângulos diferentes das demais; T6- uréia – largura de distribuição média e direcionamento do produto intermediário; T7- uréia – largura de distribuição menor e direcionamento do produto mais para o centro;...
Among the preliminary to the smooth conduct of a culture installed the field is set, seeking to correct the chemical properties of soil and and also the fertilizing to throw, traditionally used in covering, and today in a new tendency, in daily pre-planting. There is no field or reliable information on the majority of machines available in the Brazilian market concerning the quality of the application made by such equipment as well as its effective width of work. This width is determined as a function of the regular minimum strength, obtained from the overlap with adjacent past. The determination of the width of work or effective width is defined from standardized tests. Liming, in most cases is done with machines called specialized applications of fertilizers and corrective. The machines are divided as the mechanism doser in centrifugal and continuous thread. Quantities ideals are obtained through specific formulas. The experiment was carried out in 2008, on the the Experimental Farm Lageado of São Paulo State University in Botucatu, on soil classified as Dystroferric Red Nitosol.This study aimed to evaluate the performance of primary distributor with a haul in the application of lime and urea with 4 different positions of fins on the disks in the same speed of displacement of the tractor. The treatments were: T1-lime - average width of distribution and product direction of the intermediary, T2-lime - width of distribution and lower direction of the product more to the center; T3-lime - width and direction of greater distribution of the product more to the extremities; T4-lime - adjustment of only two fins at different angles of the other; T5-urea - adjustment of only two fins at different angles of the other; T6-urea - average width of distribution and product direction of the intermediary; T7 -urea - width of distribution and lower direction of the product more to the center;... (Complete abstract click electronic access below)
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Ehnbom, Victor, and Filip Kumlin. "Reliability Based Design of Lime-Cement Columns based on Total Settlement Criterion." Thesis, KTH, Jord- och bergmekanik, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-41768.
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The geotechnical community has since decades been acquainted with the use of statistical approach for design optimizations. This has been approved as an operational method by many practitioners in the field but is yet to see a major full-scale breakthrough and acceptance in practice. The advantage of quantifying the many different sources of uncertainties in a design is already a fairly acknowledged method and is in this report expanded for the use in the case of road embankments founded on soft soil improved by lime-cement columns. Statistical approach was adopted with practice of reliability base design (RBD ) to consider the importance of ingoing variables’ variability with the target of streamlining the result by decreasing uncertainties (by means of increased measurements, careful installation, etc.). By constructing a working model that gives the corresponding area ratio between columns and soil needed to fulfill the different criterion set as input values, weight is put on investigating the effects of different coefficients of variation (COV ). The analyses show that the property variabilities have a significant influence on the requisite area ratio that an active use of RBD is a useful tool for optimizing designs in geotechnical engineering. The methodology favors the contractors own development of the mixing process since higher design values can be utilized when
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Andrade, Luiz Antonio de 1956. "Avaliação hidráulica e de resistência a tração de dois modelos de mangueiras gotejadoras /." Botucatu : [s.n.], 2005. http://hdl.handle.net/11449/93815.
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Orientador: João Carlos Cury SaadBanca: Ramiundo Leite Cruz
Banca: Tarlei Arriel Botrel
Resumo: A irrigação por gotejamento no Brasil ganhou novo impulso a partir dos anos 90, quando diversas empresas internacionais especializadas neste mercado aportaram por aqui. Alguns destes produtos que estão no mercado, quando apresentam informações técnicas, normalmente não estão em Português. A existência de normas de avaliação que sejam aceitas pela comunidade tem grande valia para os que escolhem, projetam, compram, instalam, operam e avaliam equipamentos de irrigação. Uma norma estabelecida representa o estado da arte em sua área de atuação. A ISO 9261:2004 é uma norma internacional que orienta como avaliar e especificar gotejadores (emissores com vazão menor ou igual a 24 L.h-1) e entre outras informações, defini o que é uma mangueira gotejadora colapsável, ou fita do Inglês "tape". O ensaio de resistência à tensão conforme a ISO 9261:2004 é uma ferramenta útil para classificar um modelo de mangueira gotejadora em reutilizável e não reutilizável. A mangueira reutilizável pode ser removida do campo e ser reinstalada de uma época de cultivo para outra. A mangueira gotejadora não reutilizável não é adequada para ser removida do campo para outra reinstalação. O objetivo deste estudo foi a de aplicar a ISO 9261:2004 na avaliação de mangueiras gotejadoras colapsáveis, daqui em diante citada como mangueira (s) gotejadora (s). No Laboratório de Irrigação da Universidade Estadual Paulista "Julio de Mesquita Filho" - Faculdade de Ciências Agronômicas, ensaiou-se duas mangueiras gotejadoras de acordo com a norma ISO 9261:2004. Uma marca é o Golden Drip fabricado na Coréia do Sul pela empresa Seo Won Inc, e a outra é um protótipo em fase de testes, codificado como P2015, da empresa Petroisa Brasil. Os dois produtos avaliados não foram especificados e/ou fabricados de acordo com a norma ISO 9261. As duas mangueiras gotejadoras são similares visualmente...(Resumo completo, clicar acesso eletrônico abaixo)
Abstract: Drip irrigation systems in Brazilian Market have had an increase after 90's, when several expertise international corporations in that business came here. Some drip tapes that farmers can find in Brazilian Market, donþt have technical information in Portuguese language. Standards in their respective areas can be important tools for people who select, design, purchase, install, operate and evaluate irrigation equipment. 5 The ISO 9261:2004 gives mechanical and functional requirements for agricultural irrigation emitters and emitting pipes, and, provides methods for testing conformity with such requirements. It also specifies the data to be supplied by the manufacturer to permit correct information, installation and operation in the field. It is applicable to emitters, emitting and dripping (trickling) pipes, hoses, including collapsible hoses ("tapes") and tubing of which the emitting units form an integral part, to emitters and emitting units with or without pressure regulation and with flow rates not exceeding 24 L.h-1 per outlet. It is not applicable to porous pipe, nor does it cover the performance of pipes as regards clogging. The carry out the resistence to tension for emitting pipe is a good tool to classify in non-reusable and reusable emitting pipes. Non-reusable emitting pipe is not intended for removal from the field and reinstallation. Reusable emitting pipe is designed for removal from the field and reinstallation with proper handling from one season to another or under other circumstances. This work was developed at the Irrigation Laboratory - UNESP to evaluate two drip collapsible hose (P2015 and Golden Drip) according to ISO 9261:2004. The Golden Drip is a commercial product from South Korea and P2015 is an industrial prototype from Petroisa Brasil. Both drip tape are similar. The raw material is basic polyethylene resin added with UV protection...(Complete abstract click electronic access below)
Mestre
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Cornebise, Julien. "Méthodes de Monte Carlo séquentielles adaptatives." Paris 6, 2009. http://www.theses.fr/2009PA066152.
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Almond, John. "Generalised analytic queueing network models : the need, creation, development and validation of mathematical and computational tools for the construction of analytic queueing network models capturing more critical system behaviour." Thesis, University of Bradford, 1988. http://hdl.handle.net/10454/3741.
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Modelling is an important technique in the comprehension and management of complex systems. Queueing network models capture most relevant information from computer system and network behaviour. The construction and resolution of these models is constrained by many factors. Approximations contain detail lost for exact solution and/or provide results at lower cost than simulation. Information at the resource and interactive command level is gathered with monitors under ULTRIX'. Validation studies indicate central processor service times are highly variable on the system. More pessimistic predictions assuming this variability are in part verified by observation. The utility of the Generalised Exponential (GE) as a distribution parameterised by mean and variance is explored. Small networks of GE service centres can be solved exactly using methods proposed for Generalised Stochastic Petri Nets. For two centre. systems of GE type a new technique simplifying the balance equations is developed. A very efficient "building bglloocbka"l. is presented for exactly solving two centre systems with service or transfer blocking, Bernoulli feedback and load dependent rate, multiple GE servers. In the tandem finite buffer algorithm the building block illustrates problems encountered modelling high variability in blocking networks. A parametric validation study is made of approximations for single class closed networks of First-Come-First-Served (FCFS) centres with general service times. The multiserver extension using the building block is validated. Finally the Maximum Entropy approximation is extended to FCFS centres with multiple chains and implemented with computationally efficient convolution.
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Andrade, Luiz Antonio de [UNESP]. "Avaliação hidráulica e de resistência a tração de dois modelos de mangueiras gotejadoras." Universidade Estadual Paulista (UNESP), 2005. http://hdl.handle.net/11449/93815.
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andrade_la_me_botfca.pdf: 1207218 bytes, checksum: c40efa691ed75ddb73200db6e9eaa325 (MD5)Universidade Estadual Paulista (UNESP)
A irrigação por gotejamento no Brasil ganhou novo impulso a partir dos anos 90, quando diversas empresas internacionais especializadas neste mercado aportaram por aqui. Alguns destes produtos que estão no mercado, quando apresentam informações técnicas, normalmente não estão em Português. A existência de normas de avaliação que sejam aceitas pela comunidade tem grande valia para os que escolhem, projetam, compram, instalam, operam e avaliam equipamentos de irrigação. Uma norma estabelecida representa o estado da arte em sua área de atuação. A ISO 9261:2004 é uma norma internacional que orienta como avaliar e especificar gotejadores (emissores com vazão menor ou igual a 24 L.h-1) e entre outras informações, defini o que é uma mangueira gotejadora colapsável, ou fita do Inglês tape. O ensaio de resistência à tensão conforme a ISO 9261:2004 é uma ferramenta útil para classificar um modelo de mangueira gotejadora em reutilizável e não reutilizável. A mangueira reutilizável pode ser removida do campo e ser reinstalada de uma época de cultivo para outra. A mangueira gotejadora não reutilizável não é adequada para ser removida do campo para outra reinstalação. O objetivo deste estudo foi a de aplicar a ISO 9261:2004 na avaliação de mangueiras gotejadoras colapsáveis, daqui em diante citada como mangueira (s) gotejadora (s). No Laboratório de Irrigação da Universidade Estadual Paulista Julio de Mesquita Filho - Faculdade de Ciências Agronômicas, ensaiou-se duas mangueiras gotejadoras de acordo com a norma ISO 9261:2004. Uma marca é o Golden Drip fabricado na Coréia do Sul pela empresa Seo Won Inc, e a outra é um protótipo em fase de testes, codificado como P2015, da empresa Petroisa Brasil. Os dois produtos avaliados não foram especificados e/ou fabricados de acordo com a norma ISO 9261. As duas mangueiras gotejadoras são similares visualmente...
Drip irrigation systems in Brazilian Market have had an increase after 90`s, when several expertise international corporations in that business came here. Some drip tapes that farmers can find in Brazilian Market, donþt have technical information in Portuguese language. Standards in their respective areas can be important tools for people who select, design, purchase, install, operate and evaluate irrigation equipment. 5 The ISO 9261:2004 gives mechanical and functional requirements for agricultural irrigation emitters and emitting pipes, and, provides methods for testing conformity with such requirements. It also specifies the data to be supplied by the manufacturer to permit correct information, installation and operation in the field. It is applicable to emitters, emitting and dripping (trickling) pipes, hoses, including collapsible hoses (tapes) and tubing of which the emitting units form an integral part, to emitters and emitting units with or without pressure regulation and with flow rates not exceeding 24 L.h-1 per outlet. It is not applicable to porous pipe, nor does it cover the performance of pipes as regards clogging. The carry out the resistence to tension for emitting pipe is a good tool to classify in non-reusable and reusable emitting pipes. Non-reusable emitting pipe is not intended for removal from the field and reinstallation. Reusable emitting pipe is designed for removal from the field and reinstallation with proper handling from one season to another or under other circumstances. This work was developed at the Irrigation Laboratory - UNESP to evaluate two drip collapsible hose (P2015 and Golden Drip) according to ISO 9261:2004. The Golden Drip is a commercial product from South Korea and P2015 is an industrial prototype from Petroisa Brasil. Both drip tape are similar. The raw material is basic polyethylene resin added with UV protection...(Complete abstract click electronic access below)
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Flach-Malaspina, Nicolas. "Conception globale d'une pompe à chaleur air / eau à puissance variable pour le secteur résidentiel." Phd thesis, Paris, ENMP, 2004. http://www.theses.fr/2004ENMP1227.
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Ekesiöö, Anton, and Andreas Ekhamre. "Safety formats for non-linear finite element analyses of reinforced concrete beams loaded to shear failure." Thesis, KTH, Betongbyggnad, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-231087.
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There exists several different methods that can be used to implement a level of safety when performing non-linear finite element analysis of a structure. These methods are called safety formats and they estimate safety by different means and formulas which are partly discussed further in this thesis. The aim of this master thesis is to evaluate a model uncertainty factor for one safety format method called the estimation of coefficient of variation method (ECOV) since it is suggested to be included in the next version of Eurocode. The ECOV method will also be compared with the most common and widely used safety format which is the partial factor method (PF). The first part of this thesis presents the different safety formats more thoroughly followed by a theoretical part. The theory part aims to provide a deeper knowledge for the finite element method and non-linear finite element analysis together with some beam theory that explains shear mechanism in different beam types. The study was conducted on six beams in total, three deep beams and three slender beams. The deep beams were previously tested in the 1970s and the slender beams were previously tested in the 1990s, both test series were performed in a laboratory. All beams failed due to shear in the experimental tests. A detailed description of the beams are presented in the thesis. The simulations of the beams were all performed in the FEM- programme ATENA 2D to obtain high resemblance to the experimental test. In the results from the simulations it could be observed that the ECOV method generally got a higher capacity than the PF method. For the slender beams both methods received rather high design capacities with a mean of about 82% of the experimental capacity. For the deep beams both method reached low design capacities with a mean of around 46% of the experimental capacity. The results regarding the model uncertainty factor showed that the mean value for slender beams should be around 1.06 and for deep beams it should be around 1.25.
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Medina, Oscar F. "Analysis of Pre-ictal and Non-Ictal EEG Activity: An EMOTIV and LabVIEW Approach." Thesis, University of North Texas, 2016. https://digital.library.unt.edu/ark:/67531/metadc955040/.
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In the past few years, the study of electrical activity in the brain and its interactions with the body has become popular among researchers. One of the hottest topics related to brain activity is the epileptic seizure prediction. Currently, there are several techniques on how to predict a seizure; however, most of the techniques found in research papers are just mathematical models and not system implementations. The seizure prediction approach proposed in this thesis paper is achieved using the EMOTIV Epoc+ headset, MATLAB, and LabVIEW as the analog and digital signal processing devices. In addition, this thesis project incorporates the use of the Hilbert Huang transform (HHT) method to obtain intrinsic mode functions (IMF) and instantaneous frequency components of the transform. From the IMFs, features as variation coefficient (VC) and fluctuation indexes (FI) are extracted to feed a support vector machine that classifies the EEG data as pre-ictal and non-ictal EEGs. Outstanding patterns in non-ictal and pre-ictal are observed and demonstrated by significant differences between both types of EEG signals. In other words, a classification of EEG signals according to a category can be achieved proving that an epileptic seizure prediction technology has a future in engineering and biotechnology fields.
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Forkman, F. Johannes. "Coefficients of variation : an approximate F-test /." Uppsala : Dept. of Biometry and Engineering, Swedish University of Agricultural Sciences, 2005. http://epsilon.slu.se/10058368.pdf.
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Jonsson, Signe. "Automaticity in L2 learning: Correlation between vocabulary proficiency and response time in word recognition." Thesis, Stockholms universitet, Engelska institutionen, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-130831.
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Automaticity (in this essay defined as short response time) and fluency in language use are closely connected to each other and some research has been conducted regarding some of the aspects involved. In fact, the notion of automaticity is still debated and many definitions and opinions on what automaticity is have been suggested (Andersson,1987, 1992, 1993, Logan, 1988, Segalowitz, 2010). One aspect that still needs more research is the correlation between vocabulary proficiency (a person’s knowledge about words and ability to use them correctly) and response time in word recognition. Therefore, the aim of this study has been to investigate this correlation using two different tests; one vocabulary size test (Paul Nation) and one lexical decision task (SuperLab) that measures both response time and accuracy. 23 Swedish students partaking in the English 7 course in upper secondary Swedish school were tested. The data were analyzed using a quantitative method where the average values and correlations from the test were used to compare the results. The correlations were calculated using Pearson’s Coefficient Correlations Calculator. The empirical study indicates that vocabulary proficiency is not strongly correlated with shorter response times in word recognition. Rather, the data indicate that L2 learners instead are sensitive to the frequency levels of the vocabulary. The accuracy (number of correct recognized words) and response times correlate with the frequency level of the tested words. This indicates that factors other than vocabulary proficiency are important for the ability to recognize words quickly.
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Amini, Malaki Afshin. "A Study of the Effects of Operational Time Variability in Assembly Lines with Linear Walking Workers." Thesis, Tekniska Högskolan, Högskolan i Jönköping, JTH, Industriell organisation och produktion, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-17877.
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In the present fierce global competition, poor responsiveness, low flexibility to meet the uncertainty of demand, and the low efficiency of traditional assembly lines are adequate motives to persuade manufacturers to adopt highly flexible production tools such as cross-trained workers who move along the assembly line while carrying out their planned jobs at different stations [1]. Cross-trained workers can be applied in various models in assembly lines. A novel model which taken into consideration in many industries nowadays is called the linear walking worker assembly line and employs workers who travel along the line and fully assemble the product from beginning to end [2]. However, these flexible assembly lines consistently endure imbalance in their stations which causes a significant loss in the efficiency of the lines. The operational time variability is one of the main sources of this imbalance [3] and is the focus of this study which investigated the possibility of decreasing the mentioned loss by arranging workers with different variability in a special order in walking worker assembly lines. The problem motivation comes from the literature of unbalanced lines which is focused on bowl phenomenon. Hillier and Boling [4] indicated that unbalancing a line in a bowl shape could reach the optimal production rate and called it bowl phenomenon. This study chose a conceptual design proposed by a local automotive company as a case study and a discrete event simulation study as the research method to inspect the questions and hypotheses of this research. The results showed an improvement of about 2.4% in the throughput due to arranging workers in a specific order, which is significant compared to the fixed line one which had 1 to 2 percent improvement. In addition, analysis of the results concluded that having the most improvement requires grouping all low skill workers together. However, the pattern of imbalance is significantly effective in this improvement concerning validity and magnitude.
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Moura, Kallyo Halyson Santos. "Determinação do tamanho da amostra para avaliação de híbridos de melão amarelo." Universidade Federal Rural do Semi-Árido, 2008. http://bdtd.ufersa.edu.br:80/tede/handle/tede/63.
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The sample size in experiments should be determined so that it can accurately estimate the parameters of interest and to save time, labor and resources. The objective of the present work was to determine the sample size in evaluation experiments of melon hybrids in Mossoró. An experiment was carried out in randomized blocks with three replications to evaluate twenty yellow melon hybrids. The experimental plot consisted of two rows of 5.0 m with twenty plants in the spacing of 2.0 x 0.5 m. The traits evaluated were pulp thickness and firmness, content of soluble solids and fruit mean weight. Data were taken plant to plant, identifying each one harvested fruits. The methods used were of bootstrap resampling, linear model in plateau, sampling ntensity and modified maximum curvature to determine the sample size. The sample size recommended to determining for pulp thickness, fruit mean weight, content of soluble solidsand pulp firmness is 13, 13, 9 and 8 fruits, respectively. The Minimum sample size determined by modified maximum curvature method to pulp thickness, fruit mean weight, content of soluble solids and pulp firmness were 6,32; 7,35; 5,32and 3,25, respectively
O tamanho da amostra em experimentos deve ser determinado para que se possa estimar com precisão adequada os parâmetros de interesse e economizar tempo, mão-de-obra e recursos. O objetivo do presente trabalho foi determinar o tamanho da amostra para avaliação de híbridos de melão amarelo. Foi conduzido um experimento em blocos casualizados com três repetições para avaliar vinte híbridos de melão. A parcela utilizada foi constituída por duas linhas de 5,0 m com vinte plantas no espaçamento de 2,0 x 0,5 m. As características avaliadas foram as seguintes: espessura da polpa, firmeza da polpa, teor de sólidos solúveis e peso médio do fruto. Os dados foram tomados planta a planta, identificando cada um dos frutos colhidos. Foram utilizados os métodos de reamostragem bootstrap, modelo linear segmentado com platô, intensidade de amostragem e máxima curvatura para determinar o tamanho da amostra. O tamanho de amostra recomendado para determinação da espessura da polpa, peso médio do fruto, teor de sólidos solúveis e firmeza da polpa é de 13, 13, 9 e 8 frutos, respectivamente. Os tamanhos mínimos da amostra, obtidos pelo método da máxima curvatura modificada, foram 6,32; 7,35; 5,32 e 3,25 para espessura da polpa, peso médio do fruto, teor de sólidos solúveis e firmeza da polpa, respectivamente
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Волкова, Е. С., and E. S. Volkova. "Совершенствование методики оценки уровня конкурентоспособности региона : магистерская диссертация." Master's thesis, б. и, 2020. http://hdl.handle.net/10995/86554.
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Regional competitiveness is a complex concept that includes not only economic, but also social, demographic and political aspects. Different indicators that characterize even one aspect of competitiveness can give polar estimates of its level. Taking into account this differentiation is certainly important. The purpose of the final qualification work is to develop methodological foundations for analyzing the competitiveness of the region. The paper studies theoretical and methodological issues of regional competitiveness research, conducts a critical analysis of widely used methods, and offers the author's methodological approach to assessing the level of regional competitiveness. The empirical base of the study was educational and research literature, statistical data of the Federal state statistics service and its territorial divisions, data from the Unified interdepartmental information and statistical system, analytical reports of the Federal state statistics service and its territorial divisions, and data from an expert survey. In the final qualification work, a methodological approach to assessing the level of competitiveness of the region was developed.Конкурентоспособность региона - комплексное понятие, которое включает в себя не только экономические, но и социальные, демографические и политические аспекты. Различные показатели, характеризующие даже один аспект конкурентоспособности, могут давать полярные оценки ее уровня. Учет такой дифференцированности, безусловно, важен. Целью выпускной квалификационной работы является развитие методических основ анализа конкурентоспособности региона. В работе изучены теоретико-методические вопросы исследования конкурентоспособности региона, проведен критический анализ широко применяемых методик и предложен авторский методический подход оценки уровня конкурентоспособности региона. Эмпирической базой исследования выступили учебно-методическая и научно-исследовательская литература, статистические данные Федеральной службы государственной статистики и ее территориальных подразделений, данные Единой межведомственной информационно-статистической системы, аналитические отчеты Федеральной службы государственной статистики и ее территориальных подразделений, данные экспертного опроса. В выпускной квалификационной работе разработан методический подход к оценке уровня конкурентоспособности региона.
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Pellegrini, Caius Barcellos. "Precisão da estimativa da massa de forragem com discos medidores em pastagem natural." Universidade Federal de Santa Maria, 2006. http://repositorio.ufsm.br/handle/1/10700.
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The objective of this work was to evaluate precision of forage mass estimatings (FM) in natural pasture (NP) with discs. The treatments were three different discs areas, respectively 0.1; 0.2 and 0.3 m2 and each one combined with three weights of discs 5, 10 and 15 kg/m2. The experimental design was Completely Randomized Design with 50 replications, in an 3 x 3 factorial arrangement (3 disc areas x 3 weights of disc). The obtained results were submitted to regression analysis between height of disc and FM determined in each date of evaluation, area and weight of disc. From the mathematical models it were obtained the coefficient of residual variation (CV). Later, were adopted the analysis of variance method in Complete Blocks Design with seven replications of an factorial experiment (3 disc areas x 3 weights of disc) of periods. The relationship between three areas of discs associated with three weights and the CV of the measures gotten with discs were quadratic and positive. The disc area of 0.1 m2 and 5 weight kg/m2 presented smaller CV of the readings obtained with disc in the evaluated periods. With the increase the disc area, increased the CV for the weights of 5 and 10 kg/m2. The relations between the three weights and areas of discs and the CV were linear and positive. The smaller weight of disc of 5 kg/m2, associated with the area 0.1 m2 presented smaller CV. Weights added of 5 and 10 kg/m2 on the same disc area increased the CV in the evaluated periods. The relation between times of evaluation and the CV were linear and positive. The disc of smaller area, 0.1 m2 and 5 weight kg/m2, presented smaller CV for MF estimate in NP, therefore the most indicated to evaluate of MF in NP. The advance of the time of evaluation increased the CV of MF estimate in NP.O objetivo do trabalho foi avaliar a precisão da estimativa da massa de forragem (MF) em pastagem natural (PN) com emprego de discos medidores. Os tratamentos foram três diferentes áreas de disco, respectivamente 0,1, 0,2 e 0,3 m2 e cada uma combinada com três pesos de disco 5, 10 e 15 kg/m2. O delineamento experimental foi inteiramente casualizado com 50 repetições, em um arranjo fatorial 3 x 3 (3 áreas de discos x 3 pesos de discos). Os resultados obtidos foram submetidos à análise de regressão entre altura do disco e MF determinada em cada data de avaliação, área e peso de disco. Dos modelos matemáticos obteve-se os coeficientes de variação residual (CV). Posteriormente, adotou-se o método de análise de variância em delineamento de blocos ao acaso com sete repetições de um experimento fatorial 3 x 3 (3 áreas de discos x 3 pesos de discos) para épocas avaliadas. As relações entre as combinações das três áreas dos discos associadas com os três pesos e o CV das medidas obtidas com disco foram quadráticas e positivas. A área de disco de 0,1 m2 e peso 5 kg/m2 apresentou o menor CV das leituras obtidas com disco nos períodos avaliados. À medida que aumentou a área de disco, aumentou o CV para os pesos de 5 e 10 kg/m2. As relações entre as combinações dos três pesos e áreas dos discos e o CV foram lineares e positivas. O menor peso de disco, de 5 kg/m2, associado à área de 0,1 m2 apresentou o menor CV. A relação entre épocas de avaliação e o CV foi linear e positiva. O disco de menor área 0,1 m2 e peso 5 kg/m2 apresentou o menor CV para a estimativa da MF da PN, sendo portanto o mais indicado para avaliar a MF da pastagem natural. O avanço da época de avaliação aumentou o CV na estimativa da MF da PN com discos.
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Kim, Jong Phil. "Efficient confidence interval methodologies for the noncentrality parameters of noncentral T-distributions." Diss., Available online, Georgia Institute of Technology, 2007, 2007. http://etd.gatech.edu/theses/available/etd-04062007-124123/.
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Thesis (Ph. D.)--Industrial and Systems Engineering, Georgia Institute of Technology, 2007.Lewis VanBrackle, Committee Member ; Brani Vidakovic, Committee Member ; Anthony J. Hayter, Committee Chair ; Nicholeta Serban, Committee Member ; Alexander Shapiro, Committee Member.
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López, Vergé Sergi. "Estudio y gestión de la variabilidad de peso vivo a lo largo del ciclo del porcino en condiciones comerciales." Doctoral thesis, Universitat Autònoma de Barcelona, 2018. http://hdl.handle.net/10803/665099.
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La variabilidad de peso vivo cobra especial relevancia en la porcicultura moderna donde la importancia de la integridad y homogeneidad del lote resulta crucial para no interrumpir los flujos de producción. Una de las consecuencias negativas de obviar la variabilidad de peso vivo es una mayor depreciación de las canales en matadero, obteniéndose un menor rendimiento económico por cerdo engordado. Por ello, el objetivo general de la presente tesis doctoral fue el de conocer algunos factores relacionados con la variabilidad de peso vivo, haciendo especial hincapié en sus efectos al final del ciclo. La variabilidad de peso vivo tiene un origen multifactorial, por lo que muchos factores deben ser tenidos en cuenta. Poder identificar estos factores resulta importante para poder tomar medidas correctoras con prontitud para poder paliar los efectos adversos en matadero. Así, en el Capítulo 4, se identificaron varios factores directamente relacionados con un menor crecimiento de los cerdos a lo largo de todo el ciclo productivo. Estos cerdos con menores tasas de crecimiento, son responsables de un aumento de la variabilidad, y, mediante una metodología de corte epidemiológico se jerarquizaron los principales factores relacionados con este menor crecimiento (peso vivo al nacimiento, días de lactación, peso vivo al destete y ganancia media diaria). El estudio, además, se realizó en tres poblaciones de cerdos independientes, obteniéndose similares resultados. De entre los factores más relevantes que inciden directamente en el arranque de los lechones en las primeras fases del ciclo productivo, destacan los días de lactación. Es posible que la duración de la lactación, además de afectar el crecimiento de los distintos cerdos de la camada (y por tanto su variabilidad) tenga un efecto que perdure hasta el sacrificio. Así, en el Capítulo 5 se confirmó que, dependiendo del manejo utilizado en las granjas, la duración de la lactación tiene un efecto importante en la variabilidad de peso vivo de los cerdos desde el destete hasta el final del ciclo. Una lactación de 26 días, así como un peso al destete de 7 kg serían los valores recomendados para optimizar el peso vivo al final del ciclo. Finalmente, si bien la variabilidad de peso vivo no puede ser erradicada en su totalidad, sí se puede intervenir para reducirla mediante estrategias de carácter práctico y que no impliquen complicaciones de tipo logístico o cambios drásticos en el sistema de producción. En este sentido, un uso correcto de los comederos en cuanto al número de animales por boca, así como una segregación de los animales en función de su peso, combinada con una alimentación diferencial sobre los cerdos de menor peso vivo fue explorado en el Capítulo 6. Los resultados en relación a los comederos mostraron un incremento del peso vivo (80,2 vs. 82,1 kg para 5,5 y 2,2 cerdos/boca respectivamente; P = 0,011) y una tendencia a disminuir el CV (10,53 vs. 8,86% para 5,5 y 2,2 cerdos/boca respectivamente; P = 0,150) al final del ciclo. En cuanto al manejo de la alimentación, los resultados fueron favorables a la alimentación ‘específica, Sp.’ comparado con el ‘estándar, Std. ', con mejores valores de peso vivo (96,2 vs. 94,1 kg para Sp. y Std. respectivamente; P <0,001) y CV (9,7 vs. 11,3% para Sp. y Std. respectivamente; P = 0,005) al sacrificio.Live weight variability is particularly important in modern pig production, because the importance of the integrity and homogeneity of the batch is crucial in order not to interrupt production flows. One of the negative consequences of not considering the variability of live weight is a greater depreciation of the carcasses at the slaughterhouse, obtaining a lower economic income per fattened pig. Regarding this problem, the general objective of this PhD thesis was to know some factors related to the variability of live weight, with special emphasis on its effects at the end of the cycle. The variability of live weight has a marked multifactorial origin; therefore, many factors should be considered. Being able to identify these factors is important to take corrective measures promptly to control or mitigate the adverse effects in slaughterhouse. Thus, in Chapter 4, several factors directly related to lower growth of pigs throughout the productive cycle were identified. These pigs with lower growth rates are responsible for an increase in variability, and, by an epidemiological approach, the main factors related to this lower growth (birth body weight, days of lactation, weaning body weight and average daily gain at different productive phases) were ranked. The study was also conducted in three independent pig populations, obtaining similar results. Among the most relevant factors that directly affect the startup of piglets in the early stages of the production cycle, highlight the lactation length. It is possible that the duration of lactation, in addition to affecting the growth of the different pigs of the litter (and therefore its variability) has an effect that lasts in the time until slaughter. Lactation length was studied in Chapter 5 and, in fact, it was confirmed that depending on the general management used in the farms, the duration of lactation has a significant effect beyond weaning until the end of the cycle in the body weight variability of the pigs. Then, lactation length around 26 days and weaning weight close to 7 kg would be the recommended values to optimize the body weight at the end of the cycle. Finally, although the variability of live weight cannot be eradicated in its entirety, it can be intervened to reduce it, and practical strategies that do not imply logistical issues or even drastic changes in the production system, would be appropriate. In this sense, a correct use of the feeders in terms of the number of animals per feeder space, as well as a segregation of the animals according to their live weight, combined with a differential feeding on the pigs of lower live weight was explored in Chapter 6. Thus, the results in relation to the feeders showed an increase in live weight (80.2 vs. 82.1 kg for 5.5 and 2.2 pigs / space respectively, P = 0.011) and a tendency to decrease the CV (10.53 vs. 8.86% for 5.5 and 2.2 pigs / space respectively, P = 0.150) at the end of the cycle. Regarding the feeding management, the results were favorable to the 'specific feed, Sp.' compared to the 'standard, Std.', with better live weight values (96.2 vs. 94.1 kg for Sp. and Std., respectively, P <0.001) and CV (9.7 vs. 11.3% for Sp and Std. respectively, P = 0.005) at slaughter.
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Schmalz, Cassiano Ricardo. "VERIFICAÇÃO DE TIPOS DE DOSADORES DE SEMENTES DE MILHO E SOJA NO NORTE DO PARANÁ." Universidade Federal de Santa Maria, 2014. http://repositorio.ufsm.br/handle/1/4823.
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The first works with Precision Agriculture in Brazil started with greater intensity from the 2000s in order to know and correct soil fertility. After long years of public-private research generated a vast database of information demonstrating that activities like sowing has become an essential step. Thus, studies on the accuracy in the distribution of seeds and seed distribution in variable density and quality of sowing methods by coefficient of variation (CV) and accuracy rate (IP), have become important tools to increase productivity. To this end, we performed a case study of the performance of types of corn and soybeans seed feeders in northern Paraná, 02 models of pneumatic seeder and 05 mechanical models (honeycomb disc). The experiments conducted during 7 years in 61 different locations, by the technical department of Pioneer Seeds, quantified the losses from failures of seeds in the row. Pneumatic seeders present numerical and statistical superiority both in the soybean as corn.Os primeiros trabalhos com Agricultura de Precisão iniciaram no Brasil com maior intensidade a partir da década de 2000 com o intuito de conhecer e corrigir a fertilidade do solo. Após longos anos de pesquisa público-privada geraram um vasto banco de informações demonstrando que atividades como a semeadura tornou-se uma etapa fundamental. Assim, estudos relativos à precisão na distribuição de sementes como a distribuição de sementes em densidade variável e qualidade da semeadura, pelos métodos de coeficiente de variação (C.V.) e índice de precisão (I.P.), tornaram-se importantes ferramentas para acréscimo da produtividade. Com este intuito, realizou-se um estudo de caso do desempenho de tipos de dosadores de sementes de milho e soja no norte do Paraná, sendo 02 modelos de semeadora pneumáticas e 05 de modelos mecânicos (disco alveolado). Os experimentos realizados durante 7 anos em 61 locais diferentes, pelo departamento técnico da Pioneer Sementes quantificaram as perdas decorrentes de falhas de sementes na linha de plantio. As semeadoras pneumáticas apresentam superioridade numérica e estatística tanto nas culturas da soja quanto do milho.
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Serrano, Dafne Isaac. "Effect of Evapotranspiration Rate on Almond Yield in California." DigitalCommons@CalPoly, 2018. https://digitalcommons.calpoly.edu/theses/1955.
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Since 2011, California has been under drought conditions. These conditions have not only affected water availability for farmers, but also production. California’s second most valuable crop, almonds, has been affected by drought conditions. This study used three models (Model 1-3) to describe almond yield variability from year to year and almond yield variability within a year in Kern County, CA. The study evaluated 185 almond farms that were classified in three locations (east side, west side and north west side). The years of the study were 2011 (wet year) and 2013-2015 (drought condition years). Model 1 determined a functional regression between almond yield and annual evapotranspiration during the 4 years of the study. The R2was 7.9%, meaning low association between both variables and high unexplained variability (92.1%). Model 2 evaluated year to year variation. A regression function between almond yield and annual evapotranspiration after adjusting for location, precipitation, chilling hours and year was made. The R2of this model 62.6%, and all the variables used had a p2was higher than Model 1; however, there was high unexplained variability (47.4%). Model 3 evaluated within-year variation. A regression function between almond yield and annual evapotranspiration after adjusting for tree age and location (east, west and northwest side) was made for each year (2011 and 2013 -2015). Coefficient of variation of evapotranspiration and soil available water storage were analyzed as additional variables in Model 3; however, they were not introduced in Model 3 due to the low increase in R2 in each year (2 of Model 3 for each year were, 60.4%, 49.7%, 53.8% and 53.2% for the years 2011, 2013-2015, respectively. Model 3 also had high unexplained almond yield variability in each year (39.6%-50.3%). This high unexplained variability leads to introduce additional variables to the functional regression model for further studies. Identifying these additional variables and having a functional regression model with high R2 would lead to understand howlow evapotranspiration could potentially lead to a positive response on yield in drought conditions; thus, making farmers improve water use efficiency and hence, lowering production cost. However, the high unexplained variability clearly indicates that evapotranspiration is only one of many factors that influence yield. If improved yield is an important outcome, future studies must examine large- scale almond-producing farms with multiple agricultural system variables.
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Genberg, Malin, and Helen Ahlgren. "Avparaffinering med Xylen versus Ttissue- clear för vävnadsmaterial vid flödescytometrisk analys av DNA ploidi." Thesis, Hälsohögskolan, Högskolan i Jönköping, HHJ. Biomedicinsk plattform, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-36539.
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Plakane, Rūta. "Seasonal Variations of Manning’s Coefficient Depending on Vegetation Conditions in Tärnsjö, Sweden." Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-325356.
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Hydrological models are used widely and they demand for multiple input variables and observations. One of those variables is Manning’s roughness coefficient. In the current literature the variability of the coefficient poses an unknown uncertainty. This study examines a small river channel located in central Sweden, and aims to determine the variability and uncertainty of the roughness coefficient during diverse vegetation conditions within the channel. During multiple field visits to the location, slope, water level and cross-section examination is performed. With numerical simulation, discharge and roughness coefficients are obtained. With the hydraulic model (HEC-RAS), stage-discharge rating curves are produced and extrapolation is applied to obtain high flows. Manning’s roughness coefficients and their uncertainties are assessed by two different approaches. Determining the coefficient in a simplified sensitivity analysis by using Manning’s equation and calibrating HEC-RAS while applying Mean absolute error (MAE) calculation. The calculated roughness coefficients presents higher range when using Manning’s equation (summer vegetation conditions – 0.2, winter vegetation conditions – 0.095). On the contrary MAE provides values closer to each other (summer – 0.15, winter – 0.11). The obtained results indicate a high variance between summer and winter vegetation conditions, producing 38 cm water level differences during high flows using Manning’s equation and 6 cm difference using the calibration of the model in HEC-RAS. These results confirm that the roughness coefficient cannot be assumed to be constant throughout different seasons as had been assumed widely when applying hydrological modelling. Throughout the study innovative approaches and methods (e.g. back-calculating from Manning’s equation and calibrating HEC-RAS based on observed water levels) are used in order to determine the consequences of ignoring the variability of the roughness coefficient. Due to the study, one can derive that vegetation needs to be considered in having an important impact on the varying roughness coefficient value and it cannot be left as a constant value within hydrological models.Hydrologiska modeller är vanligt förekommande för bestämning av vattenföringsprognoser, och kräver ett flertal indata variabler och observationer. En av variablerna är Mannings råhetskoefficient, som orsakar en okänd felmarginal i den hydrologiska modellen. Den här studien syftar till att avgöra osäkerheten av felmarginalen samt variationen av Mannings råhetskoefficient. Det görs genom att undersöka en liten bäck i centrala Sverige vid olika vegetationstillstånd. Flera fältundersökningar genomfördes där tvärsnittsmätningar, vattennivå och hydraulisk gradient bestämdes. Från numerisk simulering kan flöde och råhetskoefficienten kalkyleras. Genom den hydrauliska modellen (HEC-RAS) fås ratingkurvor för vattennivå och flöde, där extrapolering görs för de högre flödena. Mannings råhetskoefficient och dess osäkerhet undersöks med två olika tillvägagångssätt. Den första metoden bygger på att använda Mannings ekvation. Den andra metoden bygger på att först genomföra en kalibrering i HEC-RAS och sedan använda kalkylering av medel-absolut-avvikelse, ”Mean absolute error” (MAE). Råhetskoefficienten beräknad med hjälp av Mannings ekvation ger större spridning (sommar – 0.2, vinter – 0.095) än vid användning av MAE beräkning (sommar – 0.15, vinter – 0.11). Resultatet visar en stor skillnad mellan så kallad vinter och sommar vegetation. Skillnaden i vattennivå är 38 cm vid användning av första metoden och 6 cm vid användning av den andra metoden. Resultaten från den här studien visar att råhetskoefficienten inte kan antas vara stabil under olika säsonger, vilket antas vid hydrologisk modellering. Innovativa metoder, så som bak-kalkylering från Mannings ekvation och kalibrering i HEC-RAS baserad på observerade vattennivåer har används för at bestämma utvärdera konsekvenserna av att ignorera variationen av råhetskoefficienten vid modellering. Den här studien visar att variationen av råhetskoefficienten påverkas av vegetationsförhållandet och att koefficienten inte kan antas konstant för korrekt modellering.
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Elharfaoui, Echarif. "La convergence faible des U-statistiques multivariées pour des processus non stationnaires dépendants." Toulouse 3, 2003. http://www.theses.fr/2003TOU30144.
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MARACCHINI, GIANLUCA. "Vulnerabilità degli edifici esistenti: utilizzo e limiti di procedure e metodi adottati nella pratica ingegneristica per la sua valutazione e riduzione." Doctoral thesis, Università Politecnica delle Marche, 2017. http://hdl.handle.net/11566/245616.
Full textAbstract:
Il problema della mitigazione del rischio sismico degli edifici esistenti è in Italia una questione di primaria importanza, sia a causa dell’elevata vulnerabilità strutturale di gran parte del patrimonio edilizio esistente, sia a causa, nel caso degli edifici storici, del loro valore artistico e culturale. In un’ottica di prevenzione, date le scarse risorse disponibili e data la necessità di intervenire nel minor tempo possibile, risulta fondamentale poter disporre di strumenti affidabili che consentano di evitare inaccurate valutazioni di sicurezza sismica. La presente tesi affronta quindi alcune delle problematiche più importanti presenti nella pratica ingegneristica nella valutazione della sicurezza degli edifici esistenti, con particolare riferimento agli edifici in muratura ed in cemento armato.
In particolare, dopo aver brevemente descritto le principali vulnerabilità degli edifici in muratura, viene presentata quindi una analisi critica approfondita della letteratura disponibile del metodo di modellazione a telaio equivalente. Tale metodo risulta essere oggi lo strumento di modellazione più diffuso nella pratica ingegneristica oltre ad essere consigliato da diversi codici normativi nazionali e internazionali. Da tale analisi, sono stati definiti limiti e campi d’applicazione per il suo corretto di utilizzo. In particolare, il telaio equivalente può essere utilizzato come primo approccio di tipo conservativo per lo studio della risposta sismica di edifici caratterizzati da un comportamento scatolare a prevalente risposta nel piano e con una disposizione delle aperture pressoché regolare.
Diversamente da quanto accade per gli edifici esistenti in muratura, i metodi di modellazione utilizzati nella valutazione sismica degli edifici in cemento armato risultano piuttosto consolidati anche nella pratica ingegneristica. In questo caso, le maggiori fonti di incertezza presenti nella valutazione sono fornite dalla stima delle caratteristiche meccaniche delle proprietà meccaniche in situ del calcestruzzo gettato in opera. L’alta dispersione dei parametri meccanici spesso presente all’interno degli edifici esistenti in c.a., rende infatti ardua la loro rappresentazione. In questa tesi, viene proposto e applicato a sei casi studio un metodo statistico per la caratterizzazione meccanica del calcestruzzo capace di isolare alcune delle fonti di dispersione. Dall’analisi dei risultati è emerso come tale metodo sia capace di fornire una rappresentazione più accurata della dispersione effettivamente presente e di ridurre la dispersione dei risultati delle prove in situ.The mitigation of the seismic risk of existing buildings is a relevant issue in Italy due both to the high seismic vulnerability of most of the building stock and, in case of historic masonry buildings, to their high artistic and cultural value. From this point of view, due to limited resources available and the need to intervene as quickly as possible, it is essential to have reliable tools in order to avoid inaccurate seismic assessments. This thesis addresses some of the most common problems that are present in the engineering practice related to the structural assessment of existing URM and RC buildings. After having briefly described the main vulnerability of masonry buildings, this work presents a critical analysis of the equivalent frame modelling approach through an in-depth analysis of the literature. This method is today the most widespread modelling tool in the engineering practice, and suggested by national and international standards. From this analysis, the limits and the applicability domain of this method have been defined. As a general result, it has been shown that the equivalent frame model can be used as a conservative approach for the study of the global response of buildings with box-like behavior and quite regular arrangement of openings. Unlike masonry buildings, the modelling methods used in the professional practice for the seismic assessment of existing RC buildings, are well validated. In this case, one of the most important source of uncertainty is probably the evaluation of the in situ mechanical properties of the concrete. Indeed, the high dispersion of the concrete mechanical parameters makes often inaccurate the seismic assessment of these buildings. In this thesis, a statistical method for the mechanical characterization of concrete is proposed and applied to six case studies. As a result, it is showed that the proposed method is capable of providing a more accurate representation of the actually strength distribution and of reducing the dispersion obtained from in situ tests.
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Di, Prado Poliana Regina Carloni. "Parâmetros genéticos e ganhos de seleção em pimenta de bode (Capsicum chinense Jacq)." Universidade Federal de Goiás, 2013. http://repositorio.bc.ufg.br/tede/handle/tede/4644.
Full textAbstract:
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The consumption of pepper genus Capsicum is in increasing demand worldwide. However few works have been conducted aiming their utilization in plant breeding research as well as in preserving their genetic patrimonium. The objectives of this work were to estimate the genetic parameters of a pimenta de bode (Capsicum chinense Jacq) population from the Southwest of Goiás as well as to assess gains from selection carried out in that population based on six selection criteria. Twenty seven genotypes and three commercial controls were used and the experiment arranged in a completely randomized bloc design with three replicates and four plants per plot spaced by 1.2 X 0.8 m. The estimated parameters were: genetic variance σ²g, environmental variance σ²e, phenotypic variance σ²g; genetic variance coefficient CVg%, the ratio between the genetic coefficient of variance and the environmental ratio CVg/CVe, and the heritability in broad sense term h2. The criteria used from gains selection were: selection I – shortening the flowering period; II - increase harvested fruit weight in the first harvest; III – increase fruit production; IV – increase 10 fruit weight; V – reduce 10 fruit weight; VI –shorten ripening period The CVg% was above 10% for the majority of the traits tested as well as the CVg/CVe , above 1, indicating the predominance of the genetic traits in relation to the environmental factors; being these traits considered ideal for use in genetic breeding programs. Heritability in broad sense (h2) varied from 54.27 to 99.66%. The selection criteria used presenting gains from selection were I, III, IV and VI, with 10.30, 69.59, 181 and 1.31 % respectively of gains obtained for the selected trait.
O consumo de pimentas, do gênero Capsicum, possui uma crescente demanda em nível mundial. Por outro lado, poucos trabalhos têm sido realizados com a finalidade de preservar o patrimônio genético dessas espécies e também utilização deste em programas de melhoramento genético. Os objetivos deste trabalho foram estimar os parâmetros genéticos de uma população de pimenta de bode (Capsicum chinense Jacq) do sudoeste goiano e os ganhos de seleção realizados nessa população baseados em seis critérios de seleção. Foram utilzados 27 genótipos e 3 testemunhas comerciais, o experimento foi conduzido em blocos casualizados, com três repetições, quatro plantas por parcela e espaçamento de 1.2x0.8m. Os parâmetros estimados foram variâncias genética σ²g, ambiental σ²e, fenotípica σ²f, o coeficiente de variação genético CVg%, a razão entre o coeficiente de variação genético e o ambiental CVg/CVe e a herdabilidade em sentido amplo h2. Os critérios utilizados foram; seleção I: reduzir os dias para florescimento, II: aumentar o peso na primeira colheita, III: aumentar a produção de frutos, IV: aumentar o peso de 10 frutos, V: reduzir o peso de 10 frutos e VI: reduzir os dias para maturação. O CVg% foi acima de 10% para a maioria das características, o CVg/CVe foi acima de 1 para a maioria das características indicando que os fatores genéticos são predominantes em relação aos ambientais. A h2 variou de 54.27 à 99.66%. Os critérios de seleção utilizados que apresentaram ganhos de seleção foram I, III, IV, VI com 10.30, 69.59, 181, 1.31% respectivamente de ganho realizado para característica selecionada.
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Lakhssassi, Nabil. "L'antibiothérapie en parodontologie : variabilité de la sensibilité des pathogènes parodontaux à dix antibiotiques." Toulouse 3, 2004. http://www.theses.fr/2004TOU30136.
Full textAbstract:
L'empirisme lors de la prescription antibiotique en parodontologie persiste toujours. Dans la 1ère partie, nous avons procédé à une revue de la littérature concernant les bases fondamentales de l'antibiothérapie curative et préventive. La notion de variabilité de la sensibilité bactérienne a été introduite. Dans la 2è partie, nous avons étudié, à partir de 60 prélèvements de flore sous gingivale effectués chez 20 patients atteints de parodontites agressives, la variabilité de la sensibilité de 82 souches bactériennes. Dix antibiotiques ont été testés (2 méthodes d'antibiogramme). De fortes variabilités inter individuelles et intra individuelles ont été observées spécialement avec les antibiotiques dits de 1ère génération (pénicilline G, tétracycline et érythromycine) et la ciprofloxacine. P. Intermedia montra le coefficient de variation le plus élevé. La réalisation de plusieurs antibiogrammes à partir de CFU distinctes de P. Intermedia est recommandée dans les parodontites agressivesThe frequent use of antibiotics in developed countries has led to the emergence of a wide-spread bacterial resistance. The first part of our thesis reviewed all the modalities of prescribing antibiotics in periodontology. In the second part, experimental, the inter-individual and intra-individual variabilities of the antibiotic susceptibility of 82 putative micro-organisms in aggressive periodontitis (20 patients, 60 samples) has been evaluated by means of VC (variation coefficient). Inter-individual antibiotics susceptibility of periopathogens is not homogenous and seems to vary according to bacterial species and antibiotic molecules. Intra-individual variability is heterogeneous too and very random. This inter- and intra-individual variability seems to be fairly more important with old molecules (PEN G, TET, ERY) than observed with more recent ones (AMC, AMX, AMP and DOX). P. Intermedia appeared to be the less sensitive bacteria and the one that showed the highest VC
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PACE, MARIA LUCIA. "La diseguaglianza di opportunità in Italia." Doctoral thesis, Università Cattolica del Sacro Cuore, 2017. http://hdl.handle.net/10280/35716.
Full textAbstract:
La diseguaglianza dei redditi è comunemente analizzata e misurata attraverso l’impiego di varie misure quali l’indice di Gini, il coefficiente di variazione, l’indice di Theil, la varianza dei logaritmi ed altri ancora (Sen, 1970). A partire dagli anni ’90 l’applicazione di tecniche di scomposizione relative, ad esempio, all’indice di Theil hanno reso possibile quantificare due diverse componenti della diseguaglianza ovvero la disuguaglianza legata allo sforzo individuale e la disuguaglianza dovuta alle ineguali opportunità. Questa seconda componente dipende esclusivamente da fattori esogeni, non controllabili dall’individuo, e, per questa ragione, è a ragione considerata una diseguaglianza “ingiusta”. Alla componente residua della scomposizione è di solito attribuito, invece, il significato di disuguaglianza nello sforzo, ovvero quanto ciascun individuo si è impegnato per raggiungere un determinato obiettivo di successo economico. L’applicazione di questo approccio alle misure di diseguaglianza ha permesso di studiare quale tipo di disuguaglianza prevalga all’interno di un Paese e, soprattutto, quali siano le circostanze esogene che incrementano la disparità nelle opportunità. Il presente lavoro si muove lungo questa linea di ricerca proponendo un metodo per testare il peso relativo delle due componenti e la loro significativita’. Come misura di diseguaglianza si e’ scelto di considerare il coefficiente di variazione in modo da ricondurre il test ad un problema di Analisi della varianza (ANOVA) a piu’ vie. Il test viene presentato facendo riferimento ai dati dell’ISTAT e dell'indagine Bankitalia sui redditi delle famiglie. Dopo quest'analisi preliminare sulle determinanti della diseguaglianza di opportunità in Italia, si utilizza la scomposizione della diseguaglianza nelle sue due componenti: diseguaglianza di opportunità e diseguaglianza legata all'impegno, per definire univocamente l'effetto della diseguaglianza sulla crescita economica. L'analisi econometria è svolta sui dati dell'indagine sulla ricchezza e sui redditi delle famiglie forniti dalla Banca d'Italia. L'effetto viene stimato utilizzando il modello panel dinamico con il metodo di stima GMM.While the analysis of inequality has been central to economic studies for cen- turies, in recent years many studies concentrated on the distinction between in- equality of opportunity (IO) and inequality of returns to effort (IE) and attempted empirical estimates of the two components, e.g. in US and in Europe. The decompo- sition of a general inequality index into these two components allows to analyze the prevalence of fair or unfair income inequality within a country. This paper suggests to test the differences between the two sources of inequality in a simple way using the ANOVA framework adapted to decompose the coefficient of variation, to better suit the requirements of an inequality index. The proposed procedure is applied to the Italian Survey on Income and Living Condition (IT-SILC data, wave 2005 and 2011). The analysis of the results help identifying the circumstances that foster the rise of inequality of opportunities in Italy. Our analysis shows in particular, that father education, region of residence and gender result as the most relevant circumstances determining inequality of opportunity. On the other side, the role of mother education starting from a lower level, as an inequality of opportunity factor, is increasing its influence over time. The decomposition of inequality index in two components allows not only to analyze the prevalence of fair or unfair income inequality in a country, but also to find a clearer relation between inequality and growth. In fact, it is still missing an analysis of the relation between inequality of opportunity and economic growth in Italy. This paper aims at filling in that gap, by using Italian data from Bank of Italys Survey on Income and Wealth from 1998 to 2014. We choose the coefficient of variation to measure inequality of opportunity at the regional level and, then, we studied its relation with economic growth using Dynamic Panel Data models estimated through System- GMM. Finally, in order to check if the coefficient of variation could be a measure as good as the Entropy’s index, I will compare the results of the estimated panel models with the two different inequality of opportunity indeces. We evaluate the effect of inequality of opportunity on different length of the economic growth rate, going from a short term (2 years) to a very long term growth rate (10 years). Our results shows that, in Italy, inequality of opportunity is negative in the short period, but it does not have any effect on long run growth.
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PACE, MARIA LUCIA. "La diseguaglianza di opportunità in Italia." Doctoral thesis, Università Cattolica del Sacro Cuore, 2017. http://hdl.handle.net/10280/35716.
Full textAbstract:
La diseguaglianza dei redditi è comunemente analizzata e misurata attraverso l’impiego di varie misure quali l’indice di Gini, il coefficiente di variazione, l’indice di Theil, la varianza dei logaritmi ed altri ancora (Sen, 1970). A partire dagli anni ’90 l’applicazione di tecniche di scomposizione relative, ad esempio, all’indice di Theil hanno reso possibile quantificare due diverse componenti della diseguaglianza ovvero la disuguaglianza legata allo sforzo individuale e la disuguaglianza dovuta alle ineguali opportunità. Questa seconda componente dipende esclusivamente da fattori esogeni, non controllabili dall’individuo, e, per questa ragione, è a ragione considerata una diseguaglianza “ingiusta”. Alla componente residua della scomposizione è di solito attribuito, invece, il significato di disuguaglianza nello sforzo, ovvero quanto ciascun individuo si è impegnato per raggiungere un determinato obiettivo di successo economico. L’applicazione di questo approccio alle misure di diseguaglianza ha permesso di studiare quale tipo di disuguaglianza prevalga all’interno di un Paese e, soprattutto, quali siano le circostanze esogene che incrementano la disparità nelle opportunità. Il presente lavoro si muove lungo questa linea di ricerca proponendo un metodo per testare il peso relativo delle due componenti e la loro significativita’. Come misura di diseguaglianza si e’ scelto di considerare il coefficiente di variazione in modo da ricondurre il test ad un problema di Analisi della varianza (ANOVA) a piu’ vie. Il test viene presentato facendo riferimento ai dati dell’ISTAT e dell'indagine Bankitalia sui redditi delle famiglie. Dopo quest'analisi preliminare sulle determinanti della diseguaglianza di opportunità in Italia, si utilizza la scomposizione della diseguaglianza nelle sue due componenti: diseguaglianza di opportunità e diseguaglianza legata all'impegno, per definire univocamente l'effetto della diseguaglianza sulla crescita economica. L'analisi econometria è svolta sui dati dell'indagine sulla ricchezza e sui redditi delle famiglie forniti dalla Banca d'Italia. L'effetto viene stimato utilizzando il modello panel dinamico con il metodo di stima GMM.While the analysis of inequality has been central to economic studies for cen- turies, in recent years many studies concentrated on the distinction between in- equality of opportunity (IO) and inequality of returns to effort (IE) and attempted empirical estimates of the two components, e.g. in US and in Europe. The decompo- sition of a general inequality index into these two components allows to analyze the prevalence of fair or unfair income inequality within a country. This paper suggests to test the differences between the two sources of inequality in a simple way using the ANOVA framework adapted to decompose the coefficient of variation, to better suit the requirements of an inequality index. The proposed procedure is applied to the Italian Survey on Income and Living Condition (IT-SILC data, wave 2005 and 2011). The analysis of the results help identifying the circumstances that foster the rise of inequality of opportunities in Italy. Our analysis shows in particular, that father education, region of residence and gender result as the most relevant circumstances determining inequality of opportunity. On the other side, the role of mother education starting from a lower level, as an inequality of opportunity factor, is increasing its influence over time. The decomposition of inequality index in two components allows not only to analyze the prevalence of fair or unfair income inequality in a country, but also to find a clearer relation between inequality and growth. In fact, it is still missing an analysis of the relation between inequality of opportunity and economic growth in Italy. This paper aims at filling in that gap, by using Italian data from Bank of Italys Survey on Income and Wealth from 1998 to 2014. We choose the coefficient of variation to measure inequality of opportunity at the regional level and, then, we studied its relation with economic growth using Dynamic Panel Data models estimated through System- GMM. Finally, in order to check if the coefficient of variation could be a measure as good as the Entropy’s index, I will compare the results of the estimated panel models with the two different inequality of opportunity indeces. We evaluate the effect of inequality of opportunity on different length of the economic growth rate, going from a short term (2 years) to a very long term growth rate (10 years). Our results shows that, in Italy, inequality of opportunity is negative in the short period, but it does not have any effect on long run growth.
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Mahdjoub-Araibi, M'hamed. "La modélisation asymptotique d'un écoulement de fluide avec un coefficient d'échange ayant des variations microscopiques." Lille 1, 1988. http://www.theses.fr/1988LIL10147.
Full textAbstract:
Le modèle est composé de trois couches : écoulement de fluide parfait, couche limite classique et sous couche visqueuse. Etude par la méthode des développements asymptotiques raccordés de l'interaction entre la couche limite et la sous-couche visqueuse. Formulation mathématique du problème de couche limite