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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
71

Cultivo de girassol na safrinha no Oeste do Paraná: efeitos do espaçamento entre linhas e populações de plantas / Cultivation of sunflower in second season in the Western of Paraná: effects of the spacings and plant populations

Orlando, Auri Francisco 29 August 2008 (has links)
Made available in DSpace on 2017-07-10T17:37:34Z (GMT). No. of bitstreams: 1 Auri_Francisco_Orlando.pdf: 196980 bytes, checksum: 6cddf7536fa9b2995e937673a016d9dc (MD5) Previous issue date: 2008-08-29 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / In order to study the effects of changes in the spacing between row and the plant population in the agronomic performance of sunflowers, grown in second season in the western region of Paraná, led to an experiment in the field of Experimental C. Vale - Cooperative Agroindustrial in Palotina - PR. Was evaluated, the hybrid MG2 in design of blocks at random with split plots, using four spacings (E1 = 0.90 m, E2 = 0.75 m, E3 = 0.60 m and E4 = 0.45 m) and four population (P1 = 27,000, P2 = 35,000, P3 = 43,000 and P4 = 51,000 plants ha-1) with four replications. It was evaluated: plants height (AP) stem diameter (DC), leaves dry mass (MFS), dry mass stem + petiole (MSPC), dry mass chapter (MSCAP), leaf area (AF), chapter diameter (DCAP), grains mass per chapter (MGCAP), degree of filling of the chapter (GECPA), mass of a thousand grains (MMG), productivity (PROD), content of oil (TO) and production of oil (DB). There was only interaction between people in the variable spacing and AP. For variables, MSF; MSCP; MSCAP; MGCAP; AF and TO, no significant difference was observed according to the variation of the population of sunflower plants. As for variables: DC; PC; GEC; MMG; MGCAP; PROD DB and there was reduction of all these in row with population increase of sunflower plants. The change in spacing between rows to influence the culture in a meaningful way only the GECAP being the lowest values observed in populations of plants intermediate (0.60 and 0.75 m). However, the spacing between rows of sowing not proved a limiting factor and can be changed depending on the machinery available for the operations of sowing and harvesting, however must be avoided high densities of plants in any spacing. / Com objetivo de estudar os efeitos da variação do espaçamento entre linhas e da população de plantas, nos componentes de produção do girassol, híbrido MG02, cultivado nos meses de fevereiro e março, período conhecido como safrinha, na região Oeste de Paraná, conduziu-se um experimento no Campo Experimental da C.Vale - Cooperativa Agroindustrial, em Palotina PR. Avaliou-se o híbrido MG2, em delineamento de blocos ao acaso com parcelas subdivididas, utilizando quatro espaçamentos (E1 = 0,90 m, E2 = 0,75 m, E3 = 0,60 m e E4 = 0,45 m) e quatro populações (P1 = 27.000, P2 = 35.000, P3 = 43.000 e P4 = 51.000 plantas ha-1) com quatro repetições. Avaliou-se: altura de plantas (AP), diâmetro de caule (DC), massa seca de folhas (MFS), massa seca de pecíolo + caule (MSPC), massa seca de capítulo (MSCAP), área foliar (AF), diâmetro de capítulo (DCAP), massa de grãos por capítulo (MGCAP), grau de enchimento do capítulo (GECPA), massa de mil grãos (MMG), produtividade (PROD), teor de óleo (TO) e produção de óleo (PO). Houve interação entre espaçamento e população na variável AP. Para as variáveis, MSF; MSCP; MSCAP; MGCAP; AF e TO, não foi observada diferença significativa em função da variação da população de plantas de girassol. Quanto às variáveis: DC; PC; GEC; MMG; MGCAP; PO e PROD houve redução de todas, em função do aumento da população de plantas de girassol. Ha variação do espaçamento entre linhas para a cultura influenciou de forma significativa apenas o GECAP sendo os menores valores observados nas populações de plantas intermediárias (0,60 e 0,75 m). Contudo, o espaçamento entre linhas de semeadura não mostrou ser um fator limitante, podendo ser alterado em função do maquinário disponível para as operações de semeadura e colheita, no entanto devem-se evitar altas densidades de plantas em qualquer espaçamento
72

The Optimization of Well Spacing in a Coalbed Methane Reservoir

Sinurat, Pahala Dominicus 2010 December 1900 (has links)
Numerical reservoir simulation has been used to describe mechanism of methane gas desorption process, diffusion process, and fluid flow in a coalbed methane reservoir. The reservoir simulation model reflects the response of a reservoir system and the relationship among coalbed methane reservoir properties, operation procedures, and gas production. This work presents a procedure to select the optimum well spacing scenario by using a reservoir simulation. This work uses a two-phase compositional simulator with a dual porosity model to investigate well-spacing effects on coalbed methane production performance and methane recovery. Because of reservoir parameters uncertainty, a sensitivity and parametric study are required to investigate the effects of parameter variability on coalbed methane reservoir production performance and methane recovery. This thesis includes a reservoir parameter screening procedures based on a sensitivity and parametric study. Considering the tremendous amounts of simulation runs required, this work uses a regression analysis to replace the numerical simulation model for each wellspacing scenario. A Monte Carlo simulation has been applied to present the probability function. Incorporated with the Monte Carlo simulation approach, this thesis proposes a well-spacing study procedure to determine the optimum coalbed methane development scenario. The study workflow is applied in a North America basin resulting in distinct Net Present Value predictions between each well-spacing design and an optimum range of well-spacing for a particular basin area.
73

Integrated Multi-Well Reservoir and Decision Model to Determine Optimal Well Spacing in Unconventional Gas Reservoirs

Ortiz Prada, Rubiel Paul 2010 December 1900 (has links)
Optimizing well spacing in unconventional gas reservoirs is difficult due to complex heterogeneity, large variability and uncertainty in reservoir properties, and lack of data that increase the production uncertainty. Previous methods are either suboptimal because they do not consider subsurface uncertainty (e.g., statistical moving-window methods) or they are too time-consuming and expensive for many operators (e.g., integrated reservoir characterization and simulation studies). This research has focused on developing and extending a new technology for determining optimal well spacing in tight gas reservoirs that maximize profitability. To achieve the research objectives, an integrated multi-well reservoir and decision model that fully incorporates uncertainty was developed. The reservoir model is based on reservoir simulation technology coupled with geostatistical and Monte Carlo methods to predict production performance in unconventional gas reservoirs as a function of well spacing and different development scenarios. The variability in discounted cumulative production was used for direct integration of the reservoir model with a Bayesian decision model (developed by other members of the research team) that determines the optimal well spacing and hence the optimal development strategy. The integrated model includes two development stages with a varying Stage-1 time span. The integrated tools were applied to an illustrative example in Deep Basin (Gething D) tight gas sands in Alberta, Canada, to determine optimal development strategies. The results showed that a Stage-1 length of 1 year starting at 160-acre spacing with no further downspacing is the optimal development policy. It also showed that extending the duration of Stage 1 beyond one year does not represent an economic benefit. These results are specific to the Berland River (Gething) area and should not be generalized to other unconventional gas reservoirs. However, the proposed technology provides insight into both the value of information and the ability to incorporate learning in a dynamic development strategy. The new technology is expected to help operators determine the combination of primary and secondary development policies early in the reservoir life that profitably maximize production and minimize the number of uneconomical wells. I anticipate that this methodology will be applicable to other tight and shale gas reservoirs.
74

Data spacing and uncertainty

Wilde, Brandon Jesse Unknown Date
No description available.
75

Effect of initial stand spacing and breed on dynamic modulus of elasticity of Pinus radiata

Waghorn, Matthew J. January 2006 (has links)
Wood stiffness or modulus of elasticity (MOE) is one of the most important wood properties for solid timber applications, and as such, the efficacy of wood use, especially for structural timber is strongly related to MOE. MOE in Pinus radiata is highly variable and poorly understood. In this study, the effect of initial stand spacing and breed on outerwood MOE and the vertical distribution of MOE of Pinus radiata was assessed. Understanding positive or negative influences of growth caused by initial stand spacing and genetic material on MOE is appealing because it could enable us to better comprehend how forest growers could adapt silvicultural operations to the demands of wood processing. Physical characteristics of different breeds and propagation methods of Pinus radiata were assessed at a variety of initial stand spacings. Stem diameter, crown height, stem slenderness and branch size were all heavily influenced by stand spacing. Breed had a marginally significant influence on diameter and stem slenderness. Internode length was not affected by stand spacing, but showed sizeable differences, especially between the long internode 870 breed and the remaining growth and form (GF) breeds. Outerwood MOE was significantly (P<0.0001) influenced by stand spacing and breed, but not their interaction (P>0.05). MOE scaled positively with stand spacing. MOE increased by 39% from 5.4 GPa at 209 stems ha-1 to 7.5 GPa at 2551 stems ha-1. The majority of this increase (33%) occurred between 209 and 835 stems ha-1. Physiologically aged cuttings of greater maturation status exhibited greater MOE, with the three-year-old cuttings being stiffer than the one-year-old cuttings, seedlings from the 870, 268 and 850 series, by 15, 17, 22 and 27%, respectively. Stem slenderness exhibited the strongest significant (P<0.0001) relationship with MOE (r2=0.49), followed by green crown height (r2=0.46) and diameter (r2=0.44). Stem slenderness and green crown height had a direct influence on MOE that explained 53% of the variance in MOE. MOE was also significantly (P<0.0001) influenced by spacing and breed when using the resonance technique to assess whole stem MOE. The vertical distribution of MOE showed that the lowest portion of the stem (bolt 1) was approximately 30% less stiff than bolts 2 and 3. After the greatest MOE value had been obtained at bolt 3, MOE gently declined to the top of the measured stem. Variation of MOE within trees was significant (58%) at the high stockings of 1457 and 2551 stems ha-1, but somewhat lower (36%) at the lower stockings. The 870 breed was approximately 8% and 16% stiffer than the 268 and 850 breeding series respectively, across all stockings, with the three-year-old cuttings being 7% stiffer than the one-year-old cuttings. At stockings of 481 stems ha-1 and less, the proportional height at which MOE was greatest within a tree was between 25% and 50% of stem height. At stockings above 481 stems ha-1 the proportional height at which maximum MOE was obtained was between 15% and 40% of stem height. Bolt slenderness was found to be the most significant factor impacting on MOE of the bolt. Regression of critical buckling height against diameter at ground level yielded a scaling exponent of 0.55, which was lower than the scaling exponent of 0.67 predicted with constant density-specific stiffness. There was a tendency for some bolts with lower mean diameter to display significantly higher safety margins than bolts with higher mean diameter, suggesting that the largest bolts, which occur at the base of tree, are the point of most likely critical failure.
76

Data spacing and uncertainty

Wilde, Brandon Jesse 11 1900 (has links)
Modeling spatial variables involves uncertainty. Uncertainty is affected by the degree to which a spatial variable has been sampled: decreased spacing between samples leads to decreased uncertainty. The reduction in uncertainty due to increased sampling is dependent on the properties of the variable being modeled. A densely sampled erratic variable may have a level of uncertainty similar to a sparsely sampled continuous variable. A simulation based approach is developed to quantify the relationship between uncertainty and data spacing. Reference realizations are simulated and sampled at different spacings. The samples are used to condition additional realizations from which uncertainty is quantified. A number of factors complicate the relationship between uncertainty and data spacing including the proportional effect, nonstationary variogram, classification threshold, number of realizations, data quality and modeling scale. A case study of the relationship between uncertainty and data density for bitumen thickness data from northern Alberta is presented. / Mining Engineering
77

An impedance model approach for adaptive cruise control

Sun, Xi. January 2009 (has links)
Thesis (M.S.)--University of Texas at El Paso, 2009. / Title from title screen. Vita. CD-ROM. Includes bibliographical references. Also available online.
78

Influência do espaçamento e poda de produção sobre a produtividade e aspectos tecnológicos do maracujá amarelo

Bosquê, Gisleine Galvão [UNESP] 02 September 2005 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:26:41Z (GMT). No. of bitstreams: 0 Previous issue date: 2005-09-02Bitstream added on 2014-06-13T20:15:27Z : No. of bitstreams: 1 bosque_gg_me_botfca.pdf: 353571 bytes, checksum: 7840b4f13a84cda8e79906866df30cb8 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Objetivou-se com este trabalho avaliar o efeito do adensamento de plantio, de duas épocas de poda de produção sobre a produtividade e aspectos tecnológicos dos frutos de maracujá amarelo, híbrido IAC 277 e seleção Afruvec, com uso de irrigação somente após as podas de produção realizadas no 2º ano pós-plantio. O espaçamento foi desenvolvido na Estação Experimental Campo Novo, distante 5km do Instituto de Pesquisas Meteorológicas da Unesp - Campus de Bauru. As mudas foram plantadas no dia 12 de novembro de 2002 e o sistema de condução foi o de espaldeira com 1 fio de arame liso a 1,9m de altura, com espaçamento de 3,5m entrelinhas. As práticas culturais como desbrotas laterais, poda de formação, adubações e tratamento fitossanitário, foram as empregadas tradicionalmente na cultura. O delineamento experimental foi em blocos ao acaso com 3 repetições, em parcelas sub - subdivididas, apresentando como fator principal os materiais genéticos IAC 277 e Afruvec; como fator secundário, os dois espaçamentos de plantio na linha ( 1,67 e 2,5 m entre plantas) e como fator terciário, duas épocas de podas (julho e agosto/03) e uma testemunha (sem poda). As médias foram submetidas ao teste F e comparação de médias por Tukey a 5% de probabilidade. Os parâmetros avaliados foram: produtividade e qualidade físico-químicas dos frutos produzidos nos diferentes tratamentos. Através dos resultados obtidos, pode-se concluir que: 1. O produtor deve dar preferência ao cultivo da seleção Afruvec, por ter apresentado maior número de frutos de calibre 5, em ambas as colheitas (safrinha e safra). 2. Não houve diferenças significativas na safra entre os materiais genéticos testados em relação ao ºBrix, acidez, espessura de casca exceto... / The research had as purpose to evaluate and bring near the effects of the planting and two cut seasons on the production and technological aspects of the yellow passion fruit off spring, hybrid IAC 277 and Afruvec selection using irrigated water just after the production cuts happened 2 years after planting. The trial was developed at the experimental station Campo Novo, 5 km from the Meterological Researches of UNESP- Bauru's campus. The seedling was planted on November 12th 2002 and the transport system was back rest with a flat wire of 1,9 m high and set of intervals of 3,5 between the lines. The growing practices as lateral sprout, formation prune, manuring and target treatment, was applied traditionally in the growing. The experiment all design was at randomized blocks with 3 replications on split plat showing the main factor the genetic materials, IAC 277 and Afruvec; as a secondary factor the two planting set of intervals in line (1,67 and 2,5 between the pants) and as a tertiary factor, two season cuts (July and August 2003) and a witness (without cutting) . The average was submitted to F test and average by Tukey's 5% of probability. The analyzed parameters were: productivity and chemical-physical quality of the produced fruit in different treatments. Through the obtained results we can conclude: 1. The producing must give preference to the cultivation of Afunvec selection to have shown a larger fruits number of 5 caliber in both crops (little and normal harvest). 2. There was no signifficant differences in the crops between genetic materials related to Brix, sourness, skin thickness and pulp weight. 3. Due to the lack of meaningful results between the tested set of intervals we must apply the interval of 2,5m between the plants in line and varied in the inter lines, depending the use of the place...(Complete abstract click electronic access below)
79

Diferentes sistemas de manejo do solo e espaçamentos na cultura do milho (Zea mays L.)

Silva, Antonio Renan Berchol da [UNESP] 28 May 2004 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:31:39Z (GMT). No. of bitstreams: 0 Previous issue date: 2004-05-28Bitstream added on 2014-06-13T19:20:57Z : No. of bitstreams: 1 silva_arb_dr_botfca.pdf: 905972 bytes, checksum: 1c30073979107fc7e4560bcba15ab717 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Universidade Estadual Paulista (UNESP) / O presente trabalho teve como objetivo avaliar o efeito de diferentes sistemas de manejo do solo e espaçamentos entre linhas sobre cultivares de milho, no município de Botucatu, região central do Estado de São Paulo. O experimento foi conduzido, a campo, na safra de verão dos anos agrícolas de 2000/2001 e 2001/2002, na Fazenda Experimental Lageado da Faculdade de Ciências Agronômicas - UNESP - Campus de Botucatu-SP, em solo classificado como Nitossolo Vermelho distroférrico, com clima subtropical chuvoso tipo Cfa e caracterizada por apresentar inverno com baixa precipitação pluviométrica. Utilizou-se, respectivamente, para o primeiro e segundo ano de condução do ensaio, as culturas de milheto (Pennisetum americanum) e triticale (Triticum turgidocereale) como plantas de cobertura. O delineamento experimental utilizado foi o de blocos casualizados com parcelas subdivididas com quatro repetições, nos quais foram distribuídos os três sistemas de manejo do solo (PR - preparo reduzido, PD - plantio direto e PC - preparo convencional) que compuseram as parcelas. As subparcelas, em número de oito, foram compostas pelos fatores: cultivar de milho (variedades AL-30 e AL-25 e os híbridos Aventis A-2288 e Cargil C-333B) e espaçamento entre linhas (0,90 m e 0,45 m). A população de plantas foi de aproximadamente 55.000 plantas.ha-1 para os dois espaçamentos estudados. Após as operações de preparo do solo, os melhores resultados de porcentagem de cobertura do solo foram observados no sistema de plantio direto, seguido e nessa ordem pelos sistemas de manejo reduzido e convencional. O sistema de manejo reduzido apresentou maiores valores de diâmetro médio geométrico dos agregados, área de solo mobilizado, capacidade de campo efetiva e consumo horário de combustível e, menores valores de tempo demandado, uso específico de energia e consumo de combustível por área... / The present research had the objective to evaluate different soil tillage and row spacing on corn cultivars, in the municipal district of Botucatu, central area of São Paulo State, characterized by presenting winter with rainfall scarcity. The experiment was led on the field, in 2000/2001 and 2001/2002 summer, in the Experimental Lageado Farm of Agronomic Science College, UNESP-Botucatu-SP, in a soil classified as Red Nitosoil distroferrico, with a rainy subtropical climate called Cfa, using, respectively, for the first and second period, pearl millet (Pennisetum americanum) and triticale (Triticum turgidocereale) as soil covering crops. The experimental design used was randomized blocks in split-plot design with four repetitions where the three soil tillage were distributed (PC - conventional tillage, PR - Reduced Tillage, PD - no tillage) which formed the parcels. The subdivision of the parcels, in number of eight, were composed by the factorial corn cultivar (varieties AL-30 and AL-25 and hybrids Aventis A-2288 and Cargil C-333B) and row spacing (0,90 m and 0,45 m ). The population of plants was approximately 55.000 plants.ha-1 for the two spacing. After the soil tillage operations, the best covering percentage results were observed in no tillage, being followed by reduced tillage and conventional tillage respectively. Reduced tillage presented greater aggregates geometric medium diameter, mobilized soil area, effective field capacity and consume per hour and, lower values of demanded time, energy specific use and fuel consumption per area. The parameters, tenor of water in the soil at seedling, percentage soil covering after seedling and depth of seeds deposition were also influenced by the soil tillage systems. For seedling operation, no tillage sowed at 0.90 m presented the best results of effective field capacity, demanded time, specific energy use and fuel consumption per area...(Complete abstract click electronic access below)
80

Effect of row spacing and seeding rate on grain sorghum tolerance of weeds

Hewitt, Cade Alan January 1900 (has links)
Master of Science / Department of Agronomy / J. A. Dille / Weed control in grain sorghum has always presented a challenge to producers in the semi-arid Great Plains. Cultural control tactics such as narrowing of row spacings and increasing seeding rates can be effective control methods. The objective of this research was to determine the row spacing and seeding rates that maximizes yield while suppressing weeds. Grain sorghum row spacings of 25, 51, and 76-cm and seeding rates of 75,000, 100,000, 125,000, and 150,000 seeds ha[superscript]-1 were evaluated in Kansas at Beloit and Manhattan in 2013 and Beloit, Manhattan, and Hays in 2014. Grain sorghum growth and yield response were measured in response to natural weed communities. After evaluation, Beloit was considered a low weed pressure site while Manhattan and Hays were considered to be moderate and high weed pressure sites, respectively. Grain sorghum biomass was different while weed biomass was consistent across row spacings. Yield loss equations and profit functions were derived to determine the amount of grain yield and $ ha[superscript]-1 loss from each of the three locations. Yield and profit lost was greatest amongst weedy observations. Results indicated that grain sorghum grown on wide row spacings and seeding rates of 125,000 seeds ha[superscript]-1 out yielded all other treatments under a low weed pressure site (Beloit) and narrow row spacings out yielded wider spacings in moderate and high weed pressure sites (Manhattan and Hays). These results imply that a Kansas grain sorghum producer should evaluate potential weed pressure before determining a final row spacing and seeding rate.

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