Sinking Creek, a stream in northeast Tennessee, was added to the state 303 (d) list and a TMDL for fecal coliforms developed. The study objectives were to 1) identify areas in Sinking Creek with elevated levels of fecal coliforms and 2) compare data collected to results from watershed models used in the TMDL. Fourteen sites on Sinking Creek were monitored monthly and concentrations of total coliforms, fecal coliforms, and selected physical water quality parameters measured. Fecal coliform concentrations were >1000 CFU/100 ml at sites 1 through 4, and <400 CFU/100 ml, at all other sites indicating significant inputs between sites 4 and 5. Comparisons of results from Monte Carlo simulations and watershed models indicated geometric means listed in the TMDL were on average 64% higher than results from simulations calibrated with collected data. Proposed Best Management Practices (BMP’s) included; septic tank surveys, and the use of vegetative buffer zones.

Petrobras; CNPq / Fluidos de perfuração apresentam comportamento tixotrópico e normalmente gelificam quando em repouso. A gelificação é fundamental para evitar que cascalhos provenientes da perfuração do poço se depositem sobre a broca em eventuais paradas no processo. Nessas condições são necessárias altas pressões para reiniciar o escoamento do fluido e, consequentemente, a perfuração. Por outro lado, pressões muito elevadas podem danificar as formações rochosas no fundo do poço. Dessa forma, um maior conhecimento sobre tixotropia e sobre o escoamento de materiais tixotrópicos se torna inevitável para melhor controle do processo. O mecanismo que controla o fenômeno de tixotropia ainda não é bem definido e a modelagem matemática representa um desafio. O objetivo do trabalho proposto é desenvolver um modelo matemático para o estudo da transmissão de pressão em fluidos de perfuração. A presente dissertação apresenta uma revisão de trabalhos encontrados na literatura aberta que abordam e modelam o fenômeno de tixotropia e o escoamento transitório de fluidos compressíveis. O problema é formulado como o escoamento entre o interior da coluna de perfuração e o espaço anular entre a parede externa da coluna de perfuração e a parede do poço. As equações que modelam o problema (conservação da massa, constitutiva do modelo tixotrópico, de estado e da quantidade de movimento) são discretizadas e resolvidas numericamente através de um algoritmo computacional em linguagem Fortran. O modelo é validado com resultados experimentais e numéricos obtidos da literatura. Comparações entre os dados de um fluido de perfuração utilizado em campo pela Petrobras medidos experimentalmente e calculados por três modelos viscoplásticos e um pseudoplástico são realizadas. Os fluidos viscoplásticos, devido à tensão limite de escoamento, não transmitem a pressão à saída do espaço anular. Análises de sensibilidade são realizadas mostrando o efeito da tixotropia do fluido na transmissão de pressão. / Drilling fluids present a thixotropic behavior and they usually gel when at rest. The sol-gel transition is fundamental to prevent the deposit of rock fragments, generated by drilling the well, over the drill bit during eventual stops. Under those conditions, high pressures are then required in order to break-up the gel when circulation is resumed. Moreover, very high pressures can damage the rock formation at the bottom of the well. Thus, a better understanding of thixotropy and the behavior of thixotropic materials becomes increasingly important for process control. The mechanisms that control thixotropy are not yet well defined and modeling is still a challenge. The objective of this work is to develop a mathematical model to study the pressure transmission in drilling fluids. This work presents a review of thixotropy and of different mathematical models found in the literature that are used to predict such characteristic. It also shows a review of transient flows of compressible fluids. The problem is modeled as the flow between the drillpipe and the annular region (space between the wall and the external part of the drillpipe). The equations that describe the problem (mass conservation, momentum balance, constitutive and state) are then discretized and numerically solved by using a computational algorithm in Fortran. The model is validated with experimental and numerical data obtained from the literature. Comparisons between experimental data obtained from Petrobras and calculated by three viscoplastic and one pseudoplastic models are conducted. The viscoplastic fluids, due to the yield stress, do not fully transmit the pressure to the outlet of the annular space. Sensibility analyses are then conducted in order to evaluate the thixotropic effect in pressure transmission.

The goal of thesis is an analyse of protective functions of fast-growing timber species and a set of theirs part in the total non-energic meaning. The meaning of these timber species is very wide. The analyse is focused on first of all ameliorative function, and on sinking of wind erosion impact, then on insulating function, containing appreciation of impact on sinking of noisiness and catch of dustiness in an environment, and sanitation function which is represented by the production of oxygen.

The master’s thesis deals with the topic of electrical discharge machining. The first part of the thesis contains a study of the die-sinking EDM. The die-sinking EDM of the silicon carbide ceramic is realized in the experimental part of the thesis. The result of this work was to explore the influence of the EDM sinking parameters, specifically pulse current, open-voltage and pulse on-time, on the machined surface. Furthermore, the analysis of the tool electrode was made. This analysis was focused on the wear in the corners, which has key influence on accuracy of the machining. The machining time was also examined.

This Thesis deals with the issues of violence in relation to the time of National Socialism of the second and third Generation of the survivors illustrated by the examples of the sinking of the Cap Arcona and the Neuengamme concentration camp. The main source are the Interviews with the families of the Czech survivors from Cap Arcona and Neuengamme Concentration Camp and an interview with the main management of Neuengamme monument. The approaches from the experts to the transgenerational transmission of trauma will be discussed in the theoretical part the and they will be also analyzed and evaluated.

Sinking Creek, located in upper east Tennessee, is on the 303(d) list for not meeting minimum water quality standards for recreation. A Total Maximum Daily Load (TMDL) for fecal coliforms was developed. The purpose of this study was to investigate the use of water quality parameters to identify areas that contribute to the fecal coliform loading. Concentrations of nitrate-N, orthophosphates, BOD, alkalinity, hardness, and optical brighteners (OB) were monitored at fourteen stations monthly for one year. Site 3 (agricultural region) exhibited the highest average nitrate-N loadings (627.34 mg/sec) and orthophosphate (as PO43-) loadings (84.83 mg/sec). Alkalinity loadings ranged from 10.00 mg as CaCO3/sec to 163,500.00 mgCaCO3/sec. Hardness loadings ranged from 2.00 mg as CaCO3/sec to 96,200.00 mgCaCO3/sec. The agricultural sites exhibited higher loadings for all water quality parameters measured (except OB) than the urban and forest areas. Nutrient loadings appeared to be related to agricultural land use patterns.

Fecal pollution of surface water is a significant environmental health issue. Indicator organisms are used to monitor microbial water quality, but often their presence does not coincide with the presence of pathogens. Bacterial source tracking is a term describing methods to determine the origin of fecal pollution based on bacterial traits. The objective of this research is to evaluate the use of 2 bacterial source tracking techniques, antibiotic resistance analysis (ARA) and ribotyping, to determine the sources of bacteria isolated from Sinking Creek. Based on the results of this study, ARA and ribotyping are not useful techniques for identifying sources of fecal pollution in Sinking Creek. ARA classification rates were low, and ribotype pattern generation success was 37%. The results of this study bring into question the reliability and reproducibility of these 2 source tracking methods for routine use in small watersheds.

<p>У раду је приказано истраживање реализовано са циљем проширивања знања о феномену алтернативних концепција у настави физике, са нагласком на алтернативне концепције о пливању и тоњењу тела и поређење ефеката<br />традиционалне наставе и метода активног учења на њихово превазилажење. Резултати истраживања показују широку заступљеност алтернативних концепција о пливању и тоњењу тела код испитиваних ученика седмог разреда основне школе непосредно пре реализовања наставе о сили потиска и појавама везаним за њу. Поређењем постигнућа ученика на завршном дијагностичком тесту у односу на<br />уводни утврђено је да постоје статистички значајне разлике у ефекту традиционалног модела наставе и модела наставе усмерене на активно учење о сили потиска и појавама везаним за њу на превазилажење алтернативних и усвајање научних концепата услова за пливање и тоњења тела: У контролној групи средњи нормализовани напредак износи 0.04&plusmn;0.25, а у експерименталној 0.84&plusmn;0.21. Предност применеметода активног учења над традиционалним приступом настави додатно потврђују разлике у постигнућу ученика у погледу примене и трајности усвојених знања о сили потиска и појавама везаним за њу. Основне импликације истраживања односе се на неопходност уважавања савременог конструктивистичког погледа на природу учења у наставном процесу, односно примену наставних приступа усмерених на активно учење и развој широког спектра компетенција.</p> / <p>U radu je prikazano istraživanje realizovano sa ciljem proširivanja znanja o fenomenu alternativnih koncepcija u nastavi fizike, sa naglaskom na alternativne koncepcije o plivanju i tonjenju tela i poređenje efekata<br />tradicionalne nastave i metoda aktivnog učenja na njihovo prevazilaženje. Rezultati istraživanja pokazuju široku zastupljenost alternativnih koncepcija o plivanju i tonjenju tela kod ispitivanih učenika sedmog razreda osnovne škole neposredno pre realizovanja nastave o sili potiska i pojavama vezanim za nju. Poređenjem postignuća učenika na završnom dijagnostičkom testu u odnosu na<br />uvodni utvrđeno je da postoje statistički značajne razlike u efektu tradicionalnog modela nastave i modela nastave usmerene na aktivno učenje o sili potiska i pojavama vezanim za nju na prevazilaženje alternativnih i usvajanje naučnih koncepata uslova za plivanje i tonjenja tela: U kontrolnoj grupi srednji normalizovani napredak iznosi 0.04&plusmn;0.25, a u eksperimentalnoj 0.84&plusmn;0.21. Prednost primenemetoda aktivnog učenja nad tradicionalnim pristupom nastavi dodatno potvrđuju razlike u postignuću učenika u pogledu primene i trajnosti usvojenih znanja o sili potiska i pojavama vezanim za nju. Osnovne implikacije istraživanja odnose se na neophodnost uvažavanja savremenog konstruktivističkog pogleda na prirodu učenja u nastavnom procesu, odnosno primenu nastavnih pristupa usmerenih na aktivno učenje i razvoj širokog spektra kompetencija.</p> / <p>The thesis presents an investigation implemented with the goal of expanding knowledge on the phenomenon of alternative conceptions, with emphasis on alternative conceptions on floating /and sinking and on the comparison of effects of traditional teaching and active learning methods on overcoming those alternative conceptions.The results show wide presence of alternative conceptions on floating and sinking among the subject seventh grade primary school students, immediately before teaching them about buoyancy and related phenomena. By comparing students&rsquo; achievements on the final diagnostic test with the initial test results, statistically significant differences were found between the effects of traditional teaching model and the model focused on active learning about buoyancy and related phenomena on overcoming alternative and adopting scientific concepts ofconditions leading to floating and sinking: in the control group, the average normalized gain is 0.04&plusmn;0.25, and in the experimental group it is 0.84&plusmn;0.21 . The advantage that active learning methods have over traditional&nbsp; teaching approach is additionally confirmed by differences in students&rsquo; achievements with regards to the application and long-term retention of adopted knowledge on buoyancy and related phenomena. Basic implications of the research are the need to take note of modern constructivistic view on the nature of learning in the teaching process and of the application of teaching approaches aimed at active learning and the development of a wide spectrum of competences.</p>

À medida que a tecnologia de perfuração de poços desenvolveu-se nos últimos anos, explorando cada vez maiores profundidades, os efeitos do desgaste e corrosão têm aumentado proporcionalmente. Uma forma de viabilizar a exploração em águas profundas é revestir as ligas de aço de menor custo com ligas especiais de melhores propriedades, como a liga Inconel® 625. Os parâmetros de soldagem utilizados para a deposição de camadas sobre o substrato influenciam diretamente na qualidade e nas propriedades desses revestimentos. O objetivo deste trabalho foi determinar a influência das principais variáveis de soldagem sobre a dureza ao riscamento e coeficiente de atrito da superfície originada após a deposição de cordões de solda para revestimento. Foi utilizada a técnica de soldagem TIG alimentado automaticamente com duplo arame aquecido. As variáveis estudadas foram: Corrente de Soldagem; Velocidade de Soldagem; Corrente para Aquecimento do Material de Adição; Velocidade de Alimentação do Material de Adição e Composição do Gás de Proteção. Para a realização do estudo foi elaborado um planejamento experimental (DoE), composto central, de 05 fatores, totalizando 32 condições, cada uma correspondendo a cordões de solda depositados com diferentes conjuntos de variáveis. Os cordões foram submetidos ao ensaio de riscamento, onde foram medidos a área do sulco e o coeficiente de atrito da superfície. Os riscos gerados foram analisados em tribômetro para obtenção da topografia em 3D, e em Microscópio Eletrônico de Varredura (MEV). A análise da influência das variáveis de soldagem sobre a área do sulco e o coeficiente de atrito foi realizada pela metodologia de superfície de resposta (RSM). Foram obtidos modelos matemáticos de 1ª e 2ª ordem correlacionando as variáveis de soldagem à área do sulco e ao coeficiente de atrito da superfície. Também foram geradas superfícies que correlacionam as variáveis às respostas. Observou-se que as variáveis de principal influência sobre a área do sulco são a velocidade de soldagem, corrente do arame e gás de soldagem, e que a velocidade de alimentação do arame possui forte influência quando relacionada com as outras variáveis de processo. Para o coeficiente de atrito, os fatores de maior influência foram as correlações entre as variáveis, principalmente a corrente de soldagem. / As well drilling technology has developed in recent years, exploring ever greater depths, the effects of wear and corrosion have increased proportionately. One way to make deep-water exploration feasible is to coat lower-cost steel alloys with special alloys of better properties, such as the Inconel® 625 alloy. The welding parameters used for deposition of layers on the substrate directly influence the quality and properties of these coatings. The objective of this work was to determine the influence of the main welding variables on the hardness to scratch and surface friction coefficient originated after the deposition of weld beads for coating. The GTAW welding technique was automatically fed with double heated wire. The variables studied were: Welding Current; Welding Speed; Current for Heating the Addition Material; Feed Speed of Addition Material and Shielding Gas Composition. Design of Experiments (DoE) technique was applied, central composite, of 05 factors, totalizing 32 conditions, each corresponding to weld beads deposited with different sets of variables. The beads were subjected to the scratch test, where the scar area and the surface friction coefficient were measured. The scratches were analyzed in tribometer to obtain the topography in 3D, and Scanning Electron Microscope (SEM). The analysis of the influence of the welding variables on the scar area and the friction coefficient was performed by the response surface methodology (RSM). First and second order mathematical models were obtained, correlating the welding variables to the scar area and the surface friction coefficient. Surfaces that correlate variables with responses were also generated. It was observed that the variables of main influence on the scar area are the welding speed, wire current and welding gas, and that the wire feed speed has a strong influence when related to the other process variables. For the coefficient of friction, the factors of greater influence were the correlations among the variables, mainly the welding current.

In this work, description of a basic principle of electro discharge machining and its technological possibilities was made. Possibilities of individual EDM machine producers and their comparison were described. Furthermore, the use of electro discharge machining in Zdas a.s. was shown. Trends in a development of the electro discharge technology are included, too.