Univ., Diss.--Regensburg, 2001-2002. / Literaturverz. S. [366] - 384.

Resumo: O rio Paraná, em seu trecho natural, possui padrão multicanal caracterizado por canais secundários de diferentes ordens, separando diversas ilhas e barras fluviais. As barras fluviais são formas semi-submersas associadas à disponibilidade de sedimentos e a um dinamismo temporal cujas dimensões são controladas pelo fluxo e pela profundidade. Neste estudo, pretende-se compreender os processos que promovem a formação, desenvolvimento e movimentação de uma barra de soldamento situada junto à ilha Santa Rosa, no rio Paraná, município de Porto Rico - PR. Para alcançar os objetivos propostos, foram realizados levantamentos de parâmetros hidráulicos, morfométricos e granulométricos. Nos dados levantados dos parâmetros hidráulicos, verificou-se que a presença da ilha Santa Rosa, juntamente com barra fluvial, divide o canal em dois setores de dinâmica hidráulica e sedimentar distintas. O canal principal conduz a maior parcela da vazão, é mais energético, enquanto o canal secundário apresenta valores inferiores nestes dois parâmetros. A separação do fluxo também acarreta na formação de correntes divergentes à direção principal do canal, favorecendo a diminuição da velocidade e, consequentemente, a deposição de sedimentos no entorno da ilha Santa Rosa. Averiguou-se que a morfologia da barra está diretamente vinculada às flutuações de vazão do rio Paraná: em período de águas altas há maior retrabalhamento da forma, já no período de águas médias, esta se preservou parcialmente, inclusive com afloramento em parte. Quanto aos sedimentos, as partículas de diâmetro fino distribuem-se em locais de maior velocidade de fluxo e profundidade (talvegue) em ambos os períodos analisados As partículas de diâmetro médio a grosso encontram-se no período de águas altas distribuídas pela área estudada; já no período de águas médias, estes sedimentos... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The Paraná River, in its natural stretch, has a multichannel pattern characterized by secondary channels of different orders, which separates several islands and bars. The bars are forms semi-submerged associated with the availability of sediment and a temporal dynamic, whose dimensions are controlled by the flow and depth. This study intends to understand the processes which promote formation, development and movement of the annexation bar associated to the Santa Rosa Island, located on Paraná River, near to Porto Rico - PR. To achieve the proposed aims, surveys were carried out in hydraulic, morphometric and granulometric parameters. In the data hydraulic parameters survey it was found that the presence of Santa Rosa Island along with bar divides the river channel in two sectors of distinct dynamic hydraulic and sediment. The main channel leads to a higher portion of the flow, it is more energetic, while the secondary channel has lower values in these two parameters. The separation of the flow also causes the formation of divergent currents towards the main channel, favoring the decrease in velocity and consequent deposition of sediments near to Santa Rosa Island. It was found that the morphology of the bar is directly linked to fluctuations in the flow of the Paraná River, during periods of high water there is more reworking, since in this average water period partially preserved its shape, emerging in part. As for sediment, the fine diameter particles are distributed in areas of higher flow velocity and depth (thalweg) in both analyzed periods. From medium to coarse diameter particles are, in the high-water period, distributed in the studied area, although in the average water period these sediments are located in low flow velocity and depth (Bar and Secondary Channel). Specific stream power and shields parameter values are larger in the main channel in both periods, indicating... (Complete abstract click electronic access below) / Orientador: José Cândido Stevaux / Coorientador: Mario Luis Assine / Banca: Paulo Fernando Soares / Banca: Antônio Roberto Saad / Mestre

SILVIA, Silvia Ferreira da. Avaliação do ruído e do desempenho energético de um trator de rabiças com um arado de disco acoplado. 2012. 73 f. Dissertação (Mestrado em engenharia agrícola)- Universidade Federal do Ceará, Fortaleza-CE, 2012. / Submitted by Elineudson Ribeiro (elineudsonr@gmail.com) on 2016-06-28T19:03:33Z No. of bitstreams: 1 2012_dis_sfsilva.pdf: 2169759 bytes, checksum: c7992e3e903a610067c88893f4c68971 (MD5) / Approved for entry into archive by José Jairo Viana de Sousa (jairo@ufc.br) on 2016-06-30T22:51:17Z (GMT) No. of bitstreams: 1 2012_dis_sfsilva.pdf: 2169759 bytes, checksum: c7992e3e903a610067c88893f4c68971 (MD5) / Made available in DSpace on 2016-06-30T22:51:17Z (GMT). No. of bitstreams: 1 2012_dis_sfsilva.pdf: 2169759 bytes, checksum: c7992e3e903a610067c88893f4c68971 (MD5) Previous issue date: 2012 / The initial tillage has great importance for agricultural production. This activity is usually performed by animal traction in family farming. In this paper, we studied the use of handlebar tractors as a source for field work optimization. The experiment was conducted with a handlebar tractor with a plow attached to it at the Federal University of Ceará. The goal was to evaluate the energetic efficiency of the handlebar traitor attached to the disc plow, using three gears (1st, 2nd, 3rd) in a red, yellow argisoil. It was also evaluated the soil shoaling and the noise levels with the machine both stopped in different rays of distances (1, 2, 5 and 10 meters), and with handlebar traitor in movement, using three different number of turns (810, 1040 and 1360 rpm). To obtain data about energetic efficiency, it was used a handlebar traitor, an instrument with inductive sensors on wheels to measure the wheelsets slippage, a flowmeter to measure the fuel consumption and a loading cell to obtain the workforce in the drawbar. To install the loading cell and obtain the implement stability, it was necessary to use a train, in which the set traveled 25m with three repetitions in each gear to the collecting of the data. The soil shoaling was calculated through the data obtained in the field by a profilometer, and the levels of noise were measured with a dosimeter and a decibelimeter. The studied variables were the hourly fuel consumption (L.h-1), the specific fuel consumption, (g.kW.h-1), the wheelsets slippage (%), traction force in the bar (kN), work speed (m.s-1) and available power (kW). These data were evaluated with the plow working and with the implement raised to be compared. We calculated the difference (results with the implement plowing minus the results with the plow not working) to study the obtained averages. Data analysis was performed using descriptive statistics using the computer program Assistat 7.6 beta. The results showed that the average rates of slippage were 10% (1st gear), 12 % (2nd gear) and 18% (3rd gear). The average rates for the plow while it was working for the hourly fuel consumption were 5,45 L.h-1 (1st gear), 4,22 L.h-1 (2nd gear) and 2,54 L.h-1 (3rd gear); the specific fuel consumption was 3004,98 g.kW.h-1 (1st gear), 4343,88 g.kW.h-1 (2nd gear) and 5787,91 g.kW.h-1 (3rd gear); the power was 1,54; 0,83 and 0,38 kW for 1st, 2nd and 3rd gear respectively, and the movement speed averages were 0,32 m.s-1 (1st gear), 0,41 m.s-1 (2nd gear) and 0,44 m.s-1 (3rd gear). The average rates for the hourly fuel consumption that were found for the moment when the plow was not working, that is, the implement was raised, were 6,58 L.h-1 (1st gear), 5,98 L.h-1 (2nd gear) and 4,20 L.h-1 (3rd gear); the rates for the specific fuel consumption were 3514,09 g.kW.h-1 (1st gear), 4728,22 g.kW.h-1 (2nd gear) and 5787,91 g.kW.h-1 (3rd gear); the power was 1,54 kW (1st gear), 0,83 kW (2nd gear) and 0,38 kW (3rd gear), and the movement speed averages were 0,27; 0,33 and 0,40 m.s-1 for 1st , 2nd and 3rd gears respectively. The soil shoaling achieved the rates 75 % (2nd gear) and, approximately, 64 % for the 1st and 3rd gears. And the levels of noise that were found by the usage of the dosimeter were 95,7dB(A) (1st gear), 98,2dB(A) (2nd gear) and 98,8 dB(A) (3rd gear). The average levels of noise that were found by the usage of the decibelimeter were 76,71; 77,38 and 80,80 dB(A) for the turns 810, 1.040 e 1.360 rpm respectively. It is advised the use of headphones or the decreasing of the working hours for the operator who is working directly with the tractor handlebars. / O preparo inicial do solo tem grande importância para a produção agrícola, essa atividade é geralmente realizada por tração animal na agricultura familiar. Nesse trabalho estudou-se a utilização de tratores de rabiças como fonte de otimização do trabalho no campo. O experimento foi desenvolvido com um trator de rabiças com um arado acoplado na Universidade Federal do Ceará com o objetivo de avaliar a eficiência energética do trator de rabiças acoplado ao arado de disco utilizando três marchas (1ª, 2ª e 3ª) em um Argissolo Vermelho Amarelo, avaliou-se também o empolamento do solo e os níveis de ruído com a máquina parada em diferentes raios de afastamento (1, 2, 5 e 10 m), e com o trator de rabiças em movimento utilizando três rotações (810, 1.040 e 1.360 rpm). Para obtenção de dados sobre a eficiência energética utilizou-se um trator de rabiças, instrumentado com sensores indutivos nas rodas para medir a patinagem dos rodados, fluxômetro para medida do consumo de combustível e célula de carga para obtenção da força de trabalho na barra de tração. Para instalar a célula de carga e obter estabilidade do implemento foi necessário utilizar um comboio, onde o conjunto percorria um espaço 25 m com três repetições em cada marcha para as coletas dos dados. O empolamento do solo foi calculado através de dados obtidos com o perfilometro no campo e os níveis de ruído foram medidos com dosímetro e decibelimetro. As variáveis estudadas foram consumo horário de combustível (L.h-1), consumo específico de combustível (g.kW.h-1), patinagem dos rodados (%), força de tração na barra (kN), velocidade de trabalho (m.s-1) e potência disponível (kW). Esses dados foram avaliados com o arado realizando trabalho e com o implemento erguido para ser feito de comparação calculou-se as diferença (resultados com o implemento arando, menos os resultados com o arado sem realizar trabalho), para estudo das médias obtidas. A análise dos dados foi realizada utilizando estatística descritiva utilizando o programa computacional Assistat 7.6 beta. Os resultados mostraram que os valores médios da patinagem foram de 10 % (1ª marcha), 12 % (2ª marcha) e 18 % (3ª marcha). Os valores médios encontrados para o arado realizando trabalho para o consumo horário de combustível foi de 5,45 L.h-1 (1ª marcha), 4,22 L.h-1 (2ª marcha) e 2,54 L.h-1 (3ª marcha); o consumo específico de combustível foi de 3004,98 g.kW.h-1 (1ª marcha), 4343,88 g.kW.h-1 (2ª marcha) e 5787,91 g.kW.h-1 (3ª marcha); a potência foi de 1,54; 0,83 e 0,38 kW para a 1ª, 2ª e 3ª marcha respectivamente e as médias da velocidade de deslocamento foram de 0,32 m.s-1 (1ª marcha), 0,41 m.s-1 (2ª marcha) e 0,44 m.s-1 (3ª marcha). Os valores médios encontrados para o momento em que o arado não realizava trabalho, ou seja, o implemento estava erguido foi para o consumo horário de combustível de 6,58 L.h-1 (1ª marcha), 5,98 L.h-1 (2ª marcha) e 4,20 L.h-1 (3ª marcha); o consumo específico de combustível apresentou valores de 3514,09 g.kW.h-1 (1ª marcha), 4728,22 g.kW.h-1 (2ª marcha) e 5787,91 g.kW.h-1 (3ª marcha); a potência foi de 1,54 kW (1ª marcha), 0,83 kW (2ª marcha) e 0,38 kW (3ª marcha) e as médias da velocidade de deslocamento foram de 0,27; 0,33 e 0,40 m.s-1 para a 1ª, 2ª e 3ª marchas respectivamente. O empolamento do solo chegou a 75 % (2ª marcha) e obteve valores de aproximadamente 64 % para a 1ª e 3ª marcha. E os níveis de ruído encontrados utilizando o dosimetro foram de 95,7 dB(A) (1ª marcha), de 98,2 dB(A) (2ª marcha) e 98,8 dB(A) (3ª marcha). Os níveis médios de ruído encontrados com o auxilio do decibelimetro foi de 76,71; 77,38 e 80,80 dB(A) para as rotações de 810, 1.040 e 1.360 rpm respectivamente. Recomenda-se o uso de protetores auriculares ou a diminuição da carga horária de trabalho para o operador que esteja trabalhando diretamente com o trator de rabiças.

Regression analysis constitutes a large portion of the statistical repertoire in applications. In case where such analysis is used for exploratory purposes with no previous knowledge of the structure one would not wish to impose any constraints on the problem. But in many applications we are interested in a simple parametric model to describe the structure of a system with some prior knowledge of the structure. An important example of this occurs when the experimenter has the strong belief that the regression function changes monotonically in some or all of the predictor variables in a region of interest. The analyses needed for statistical inference under such constraints are nonstandard. The specific aim of this study is to introduce a technique which can be used for statistical inferences of a multivariate simple regression with some non-standard constraints.

Magíster en Gestión para la Globalización / En este manuscrito se analiza y evalúa el establecimiento y operación de un Teahouse de estilo contemporáneo en Santiago de Chile emulando el modelo de negocios de la cadena de Teahouse Australiana "T2" (www.t2tea.com). El mercado de los Teahouse en Santiago de Chile es nuevo, por tanto su propuesta de valor coincide con la ventaja de T-Bar como primer jugador en este nicho, aportando con variedad, sofisticación y exclusividad como factores diferenciadores que lo distingan de sus posibles rivales en el mercado. En cuanto a la metodología utilizada, se optó por la proyección clásica para un plan de negocios, consistente en tres etapas: a) Estudio y análisis de mercado del té en Chile. b) Estudio del rubro de servicios en donde se pretende establecer el proyecto. c) Proyección financiera del proyecto. Luego del análisis financiero del proyecto, nos encontramos frente a una posibilidad cierta de implementación de un nuevo tipo de negocio en Chile. Los resultados de margen bruto sobre ventas de un 80% y el comienzo de ganancias en el balance general proyectado a partir del segundo mes de operaciones auguran un buen comienzo. Se concluye de esta forma que T-Bar es un negocio con futuro, de fácil implementación y operación. La potencialidad de fortalecer la marca y crear la franquicia T-Bar son incentivos para inversionistas que quieran apostar por este proyecto.

Modern agriculture often employs broad-spectrum herbicides combined with herbicide-resistant crops. Usually, this is achieved by altering the crop genom (genetic modification) by inserting of a specific gene coding for resistance to specific herbicide or group of herbicides. Apllying such herbicide thus results in minor crop damage. The resistence of crops against broad-spectrum herbicides depends on the genes, which were inserted into the genom. The gene bar is often used as a resistence -providing element. It mediates resistance against a broad spectrum of herbicides, such as glufosinate and Bialahops. For the selection of transformants and preliminary assessment of the target transgen expression level a suitable marker gene is simultaneously inserted. For this purpose, gene for bacterial ??glucuronidase (GUS) is often used. It is considered to be one of the most frequently used reporter systems for the assessment of transgen expression and also allows to analyze the expression on the tissue, cell and whole cell organelles levels. In this diploma thesis the PCR method and histochemical detection of the enzyme glucuronidase presence were used to detect and evaluate transgenic plants of cv. Golden Promise spring barley, modified by genes bar and gus. The presence of gus gene was determined in different parts of plants.

abstract: Advancements in thermal interface materials (TIMs) allows for the creation of new and more powerful electronics as they increase the heat transfer from the component to the heat sink. Current industrial options provide decent heat transfer, but the creation of TIMs with higher thermal conductivities is needed. In addition, if these TIMs are elastic in nature, their effectiveness can greatly increase as they can deal with changing interfaces without degradation of their properties. The research performed delves into this idea, creating elastic TIMs using liquid metal (LM), in this case galinstan, along with other matrix particles embedded in Polydimethylsiloxane (PDMS) to create an easy to use, relatively inexpensive, thermally conductive, but electrically insulative, pad with increased thermal conductivity from industrial solutions. The pads were created using varying amounts of LM and matrix materials ranging from copper microspheres to diamond powder mixed into PDMS using a high-speed mixer. The material was then cast into molds and cured to create the pads. Once the pads were created, the difficulty came in quantifying their thermal properties. A stepped bar apparatus (SBA) following ASTM D5470 was created to measure the thermal resistance of the pads but it was determined that thermal conductivity was a more usable metric of the pads’ performance. This meant that the pad’s in-situ thickness was needed during testing, prompting the installation of a linear encoder to measure the thickness. The design and analysis of the necessary modification and proposed future design is further detailed in the following paper. / Dissertation/Thesis / Masters Thesis Mechanical Engineering 2017

abstract: The stability of nanocrystalline microstructural features allows structural materials to be synthesized and tested in ways that have heretofore been pursued only on a limited basis, especially under dynamic loading combined with temperature effects. Thus, a recently developed, stable nanocrystalline alloy is analyzed here for quasi-static (<100 s-1) and dynamic loading (103 to 104 s-1) under uniaxial compression and tension at multiple temperatures ranging from 298-1073 K. After mechanical tests, microstructures are analyzed and possible deformation mechanisms are proposed. Following this, strain and strain rate history effects on mechanical behavior are analyzed using a combination of quasi-static and dynamic strain rate Bauschinger testing. The stable nanocrystalline material is found to exhibit limited flow stress increase with increasing strain rate as compared to that of both pure, coarse grained and nanocrystalline Cu. Further, the material microstructural features, which includes Ta nano-dispersions, is seen to pin dislocation at quasi-static strain rates, but the deformation becomes dominated by twin nucleation at high strain rates. These twins are pinned from further growth past nucleation by the Ta nano-dispersions. Testing of thermal and load history effects on the mechanical behavior reveals that when thermal energy is increased beyond 200 °C, an upturn in flow stress is present at strain rates below 104 s-1. However, in this study, this simple assumption, established 50-years ago, is shown to break-down when the average grain size and microstructural length-scale is decreased and stabilized below 100nm. This divergent strain-rate behavior is attributed to a unique microstructure that alters slip-processes and their interactions with phonons; thus enabling materials response with a constant flow-stress even at extreme conditions. Hence, the present study provides a pathway for designing and synthesizing a new-level of tough and high-energy absorbing materials. / Dissertation/Thesis / Doctoral Dissertation Mechanical Engineering 2017

A Thesis Submitted Towards the Partial Fulfilment Degree of Master of Technology (M.Tech.) FACULTY OF ENGINEERING MECHANICAL ENGINEERING DEPARTMENT Cape Peninsula University of Technology 2011 / The split Hopkinson pressure bar (SHPB) test is the most commonly used method for determining material properties at high rates of strain. The theory governing the specifics of Hopkinson bar testing has been around for decades; however, it has only been for the last decade or so that significant data processing advancements have been made. It is the intent of this thesis to offer the insight of application of SHPB to determine the compressive dynamic behaviour for welded low carbon steel (mild steel). It also focuses on the tensile behaviour for unheat-treated and heat-treated welded carbon steel. The split Hopkinson Pressure bar apparatus consists of two long slender bars that sandwich a short cylindrical specimen between them. By striking the end of a bar, a compressive stress wave is generated that immediately begins to traverse towards the specimen. Upon arrival at the specimen, the wave partially reflects back towards the impact end. The remainder of the wave transmits through the specimen and into the second bar, causing irreversible plastic deformation in the specimen. It is shown that the reflected and transmitted waves are proportional to the specimen's strain rate and stress, respectively. Specimen strain can be determined by integrating the strain rate. By monitoring the strains in the two bars and the specimen's material, stress-strain properties can be calculated. Several factors influence the accuracy of the results, including the size and type of the data logger, impedance mismatch of the bars with the specimens, the utilization of the appropriate strain gauges and the strain amplifier properties, among others. A particular area of advancement is a new technique to determine the wave's velocity in the specimen with respect to change in medium and mechanical properties, and hence increasing the range of application of SHPB. It is shown that by choosing specimen dimensions based on their impedance, the transmitted stress signal-to-noise ratio can be improved. An in depth discussion of realistic expectations of strain gages is presented, along with closed form solutions validating any claims. The thesis concludes with an analysis of experimental and predicted results. Several recommendations and conclusions are made with regard to the results obtained and areas of improvement are suggested in order to achieve accurate and more meaningful results.

The aim of this thesis is the creation of model examples for teachers that can be used in mathematics lessons on basic and secondary schools. The learners are taught how to complete picture from geometry formations set with mathematics formula. This is, according my point of view, the best way how to motivate the learners of any age. The partial aim was to create a summary of theme units which can be used as a source for the pictures' creation. The whole thesis is divided into 7 chapters. Each of them consists of the introduction to the issue, a model example and exercises on the issue and their solutions.