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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.
61

Metodologia alternativa ao preenchimento de falhas para a geração de séries de precipitação mensal média de forma automatizada em ambiente SIG / Alternative methodology to gap filling for generation of monthly rainfall series with GIS approach

Cláudio Bielenki Júnior 23 February 2018 (has links)
Alternativamente ao preenchimento de falhas, buscou-se neste estudo apresentar uma metodologia para a geração de séries de precipitações mensais médias apenas com os dados observados disponíveis nas estações pluviométricas presentes na área de estudo e seu entorno. Neste caso, para cada época da série, somente os dados disponíveis foram utilizados para o cálculo da precipitação média, assim em cada época admitiu-se que uma combinação diferente de postos pluviométricos fosse utilizada para o seu cálculo. Para isso foi desenvolvida uma ferramenta computacional em ambiente SIG para automatizar todas as etapas do estudo. Os resultados das séries de precipitação mensal média para uma bacia hidrográfica calculados segundo a metodologia alternativa apresentada foram comparados a dois métodos de preenchimento de falhas comumente utilizados nos estudos hidrológicos. Posteriormente foram avaliados os impactos do quantitativo de falhas nas séries. Também foram avaliados os reflexos na aplicação das séries na modelagem chuva-vazão e por fim a metodologia foi aplicada a um caso concreto. Os resultados encontrados e os testes estatísticos apontam resultados satisfatórios e equivalentes nas condições testadas. Verificou-se uma degradação na correlação entre a série gerada a partir dos dados sem falhas e as séries geradas com os dados com as imposições das falhas com o aumento do número de falhas impostas. As séries de vazões médias mensais geradas utilizando-se o modelo mensal SMAP quando da aplicação das séries de precipitação calculadas pela metodologia alternativa também se mostraram equivalentes, segundo os testes estatísticos realizados, às séries geradas de dados de precipitação sem falhas ou com as falhas preenchidas. As diferenças encontradas entre as séries foram pequenas o que se refletiu nos Índices de Nash-Sutcliffe que foram próximos. / In this study, we proposed a methodology for the generation of average monthly rainfall series only with the observed data available in the rainfall stations present in the study area and its surroundings. In this case, for each season of the series only the available data were used for the calculation of the average precipitation, so in each season it was admitted that a different combination of pluviometric stations was used for its calculation. For this, a computational tool was developed with a GIS approach to automate all stages of the study. The results of the average monthly rainfall series for a river basin calculated according to the alternative methodology presented were compared to two methods of filling gaps commonly used in hydrological studies. Subsequently, the impacts of the number of failures in the series were evaluated. We also evaluated the reflexes in the application of the series in the rainfall-flow modeling and finally the methodology was applied to a case study. The results found and the statistical tests show satisfactory and equivalent results under the conditions tested. There was a degradation in the correlation between the series generated from the data without fail and the series generated with the data with the impositions of the failures with the increase of the gaps imposed. The series of monthly average flows generated using the SMAP monthly model when applying the rainfall series calculated by the alternative methodology were also shown to be equivalent, according to the statistical tests carried out, to the series generated of data of precipitation without gaps or with the gaps fulfilled. The differences found between the series were small, which was reflected in the Nash-Sutcliffe Indices that were close.
62

Assessing change in the Earth's land surface albedo with moderate resolution satellite imagery

Sun, Qingsong 12 March 2016 (has links)
Land surface albedo describes the proportion of incident solar radiant flux that is reflected from the Earth's surface and therefore is a crucial parameter in modeling and monitoring attempts to capture the current climate, hydrological, and biogeochemical cycles and predict future scenarios. Due to the temporal variability and spatial heterogeneity of land surface albedo, remote sensing offers the only realistic method of monitoring albedo on a global scale. While the distribution of bright, highly reflective surfaces (clouds, snow, deserts) govern the vast majority of the fluctuation, variations in the intrinsic surface albedo due to natural and human disturbances such as urban development, fire, pests, harvesting, grazing, flooding, and erosion, as well as the natural seasonal rhythm of vegetation phenology, play a significant role as well. The development of times series of global snow-free and cloud-free albedo from remotely sensed observations over the past decade and a half offers a unique opportunity to monitor and assess the impact of these alterations to the Earth's land surface. By utilizing multiple satellite records from the MODerate-resolution Imaging Spectroradiometer (MODIS), the Multi-angle Imaging Spectroradiometer (MISR) and the Visible Infrared Imaging Radiometer Suite (VIIRS) instruments, and developing innovative spectral conversion coefficients and temporal gap-filling strategies, it has been possible to utilize the strengths of the various sensors to improve the spatial and temporal coverage of global land surface albedo retrievals. The availability of these products is particularly important in tropical regions where cloud cover obscures the forest for significant periods. In the Amazon, field ecologists have noted that some areas of the forest ecosystem respond rapidly with foliage growth at the beginning of the dry season, when sunlight can finally penetrate fully to the surface and have suggested this phenomenon can continue until reductions in water availability (particularly in times of drought) impact the growth cycle. While it has been difficult to capture this variability from individual optical satellite sensors, the temporally gap-filled albedo products developed during this research are used in a case study to monitor the Amazon during the dry season and identify the extent of these regions of foliage growth.
63

Balls Form Knit

Snedker, Christine January 2022 (has links)
Balls Form Knit explores the relationship between spherical objects as a filling material and knit to design transformable objects that offer an alternative perspective on what anatomical support can be, based on bold interaction. The expressive possibilities of weft knitting have been investigated from the perspective of generating form using the tension created by the filling. The elevation of the textile and fillings role from passive to active within the context of seating objects has been the starting point for this work. Both filling and knit have been worked with simultaneously to let them contribute to the expression of the design and let the meeting between their properties influence the form and the way an audience interacts with the objects. As a final result, the collection consisting of six textile objects presents ways in which different knit techniques and filling can be combined to create transformable objects that offer different interactions and supports for the body. Balls Form Knit engages the user to interact and be playful while finding support in a way that is intuitive and accessible.
64

Filling Method Implementing Hydraulic Lime for Reusing Mine Tailings and Improve Sustainability in Conventional Peruvian Underground Mines

Altamirano-Soto, Pablo, Supa-Urrutia, Jorge, Pehovaz-Alvarez, Humbero, Raymundo, Carlos, Mamani-Macedo, Nestor, Dominguez, Francisco 01 January 2020 (has links)
El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / Mining in Peru has existed for several decades, and for several years, there has been no proper environmental management of the impact of this activity on the environment and society in general, whether it be gas emissions, the presence of acidic water, or the generation of mining tailings. One of the most prominent examples involve mine tailings; these are by-products of mining processing plants and are stored in a dam known as a tailings dam. Like any extraction activity, mining generates large amounts of waste material that could become potential risks to the environment and society. Using hydraulic fills, the mine tailings contained in tailings dams could be reused. These fills seek to decrease the volume of stored tailings to prevent any future dam collapses, as observed in Brazil with the Vale mining company, where its tailings dam collapsed and caused more than 200 deaths.
65

Indexing Peak Rapid Filling Velocity to Both Relaxation and Filling Volume to Estimate Left Ventricular Filling Pressures

Lavine, Steven J., Sivaganam, Kamesh, Strom, Joel A. 01 June 2019 (has links)
Aims: The peak transmitral velocity/peak mitral annular velocity (E/e′) ratio has been used as a left ventricular (LV) filling pressure (LVFP) correlate. However, the E/e′ and its changes with haemodynamic alterations have not always correlated with changes in LVFP's. We hypothesized that indexing E/e′ to a measure of LV filling volume may enhance the correlation with LVFP and LVFP changes. Methods and results: We summarized previously obtained haemodynamic and Doppler echo data in 137 dogs with coronary microsphere embolization induced-chronic LV dysfunction prior to and following haemodynamic induced alterations in LVFP's. E/e′ values were obtained as E∗tau where tau is the inverse logarithmic LV pressure decay. E∗tau was indexed to LV filling volume by dividing by the diastolic time velocity integral (DVI) and correlated with LV mean diastolic pressure (LVmDP). Similarly, the relationship of E/e′ and E/e′/DVI to LV pre A wave pressure was evaluated in 84 patients by invasive haemodynamics and Doppler echo. Combining data from all interventions, LVmDP correlated with E∗tau (r = 0.408) but more strongly with E∗tau/DVI (r = 0.667, z = 3.03, P = 0.0008). The change in LVmDP correlated with the change in E∗tau/DVI (r = 0.742) more strongly than E∗Tau (r = 0.187, Z = 4.01, P < 0.0001). In the patient cohort, E/e′ was modestly correlated with LV pre A wave pressure (r = 0.301) but more strongly correlated with E/e′/DVI (r = 0.636, z = 2.36, P = 0.0161). Conclusion: Indexing E to both LV relaxation and filling volume results in a more robust relation with LVFP's and with LVFP changes.
66

Controlled loading response cemented backfill support for deep tabular stopes

Lamos, August Wilhelm January 1993 (has links)
A thesis submitted to the Faculty of Engineering, University of the Witwatersrand. Johannesburg, in fulfilment of the requirements for the degree of Doctor of Philosophy / Hydraulically placed cemented backfill is increasingly being used as a means of stope support in South African hard-rock mines. The addition of binder provides backfill with a primary compressive strength. the property for which the material has traditionally been utilised. Binder-induced cohesion, however, is not the only factor determining the quality of cemented backfill and the material's utility can be enhanced significantly by applying all of its attributes to the task of stope support. The main purpose of this thesis is, therefore, to examine those factors which influence the performance of cemented backfill, and to provide relevant and useful information for the design of improved cemented backfill mine support for tabular mining excavations. In an extensive laboratory investigation, a number of relevant factors were tested for their influence on the loading behaviour of cemented backfill. Twenty two cemented backfills. grouped according to aggregate type, water content, binder content and binder type, were analysed to determine the influence of composition on their material properties. This study was augmented by several test series on the effects of curing conditions on cemented backfill quality. In a second major investigation, the effects of geometrical parameters, including sample volume and sample width to height ratios were analysed. A further study dealt with the effect of spatially separating sample backfill ribs under normal compression, as well as at high closure rates. It is concluded, that by co-ordinating the composition design of cemented backfills with the spatial configuration of backfill support elements, it is possible to modify all phases of the cemented backfill loading response. This implies the control of the binder-induced compressive strength at low strains, the large-scale yielding behaviour of backfill support, as well as the stiffness of the backfill body at high stresses. In the light of stope support requirements. particularly under rockburst conditions, the capacity of backfill support to yield and absorb rapid stope closure and then to decelerate the hangingwall by the rapid strain-hardening of the, now, large width to height ratio backfill mass, has the potential of substantially increasing mine safety in tabular stopes, / Andrew Chakane 2020
67

Interactive Image Filling-In

Arnold, Teryl Lynne 19 April 2005 (has links) (PDF)
Removing unwanted scratches or objects from an image in an undetectable manner is a technique that has been researched for its many useful and varied applications, such as removing scratches, defects, super-imposed text, or even entire objects from a scene. Currently there is a wide variety of algorithms that fill in unwanted regions, none of which incorporate user preferences into the structure completion process. By building a framework to incorporate user preferences into the filling-in process, user input can be utilized to more effectively fill in damaged regions in an image. User input can influence the filling-in process in a variety of ways, including identifying the region to remove, guiding the completion of structure in the damaged region, influencing priority in the searching process for texture completion, and picking the best combination of structure and texture completion in the damaged region. The framework to achieve the interactive filling-in process contains five main steps. First, the scratch or deformity is detected. Second, the edges outside the deformity are detected. Third, curves are fit to the detected edges. Fourth, the structure is completed across the damaged region. Finally, texture synthesis constrained by the previously computed curves is used to fill in the intensities in the damaged region. Scratch detection, structure completion, and texture synthesis can be influenced or guided by user input when given. Defects have successfully been removed from images that contain structure, images that contain texture, and images that contain both structure and texture. A user is able to successfully complete images that contain ambiguous structure in more than one viable way by gesturing the cursor in the direction of desired structure completion.
68

The Effect of Liquid Hot Filling Temperature on Blow-Molded HDPE Bottle Properties

Hudson, Benjamin S. 04 December 2008 (has links) (PDF)
The occurrence of deformation in plastic bottles is a common problem in the bottling industry where bottles are blow molded, hot filled at high temperatures and sealed. Plastics have unique properties that make it difficult to predict when and why such changes may occur. The root cause of such deformation is unknown by many bottle producers and recent attempts have been made to minimize the occurrence of such defects. The purpose of this research is to determine which variables involved in the bottle production process influence bottle shape. Earlier variables that were tested included both blow molding resin and total bottle sidewall thickness. The result of changing these variables did not create a decrease in defects. The use of an Ishikawa fishbone diagram identified hot filling temperature a major variable that influences final bottle shape. This research summarizes the results of a series of tests that were developed to observe the effect of hot filling temperature on final bottle shape. A positive correlation between sidewall deflection and liquid hot filling temperature was observed. A series of tensile tests were also developed to analyze the strength of various regions of a blow molded bottle. An early Pareto Analysis determined that the parting line is more susceptible to defects than any other region of the bottle. This weakness was confirmed after the tensile tests proved that there is a statistically significant difference between measurements on the sidewall and parting line (pvalue < .001). The results of this thesis highlight the consequences of arbitrarily choosing a filling temperature with little understanding of the bottle's strength at high temperatures. Plastic bottle producers and hot filling companies should unite to determine the appropriate hot filling temperature before bottles are molded and filled.
69

Fractures and Fracture Filling in the Guelph Formation, Steetley Quarry Flamborough, Ontario

Campbell, Ian T. 04 1900 (has links)
<p> The North Quarry (north of Ontario Highway 4) is located in Flamborough Ontario. In it, rocks of the Guelph formation are well exposed. The Guelph formation consists of dolomite and at the North Quarry has an average thickness of 30m. These rocks are cut by three predominant joint sets which have no indication of shear motion. The 030° set was formed as a result of compaction and loading; It appears to represent an upward joint propagation mirroring the Algonquin Arch trend. Joint sets 120° and 160° are a north western analogue to the conjugate pair described by Nickelson and Hough (1967) in the north eastern United States.</p> <p> Vein data and sampled minerals, using techniques such as cathodoluminescence, photoluminescence, and isotope analysis enable paragenesis of joint propagation and crystallization relationships to be inferred. Possible stress field configurations have been deduced from these data. The joint set 030° was the first to open. Next, a minor east-west trending set opened. Joint sets 120° and 160° are the last to open. The joints were infilled by cement in the order of Organics > Calcite > Sulphides > Iron Oxides. Buckle heaves in the quarry were unreliable indicators of neotectonic stress.</p> / Thesis / Bachelor of Science (BSc)
70

Laminar Plunging Jets - Interfacial Rupture and Inception of Entrainment

Kishore, Aravind 27 October 2014 (has links)
No description available.

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