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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.
81

Píst zážehového přeplňovaného motoru 2.0L / Piston for SI Turbocharged Engine 2.0L

Kusyn, Petr January 2013 (has links)
This diploma thesis is focused on solve of design solutions for piston for turbocharged version of Honda K20A engine, especially on reduce of side force acting on piston. There are mentioned methods and on their basis also design solutions for piston to reduce this force. There is also included kinematic and dynamic analysis for each solution and as well their FEM analysis for testing the suitability of these solutions.
82

Utvärdering av faktorer för optimering av biologisk in situ-sanering av bensinförorenad mark / Evaluation of factors for optimisation of biological in situ remediation in petrol-polluted soil

Johansson, Niklas January 2021 (has links)
En av de vanligaste föroreningarna i mark och grundvatten är aromatiska kolvä- ten såsom bensen, toluen, etylbensen och xylener. Dessa härstammar från ex. ben- sin och har läckt ut till omgivande miljö från drivmedelsanläggningar. I stället för schaktning och bortforsling av de förorenade jordmassorna som mest förekom- mande ex situ-saneringsmetod behövs mer forskning kring in situ-saneringsmetoder där föroreningen alltså kan angripas på plats. I denna rapport undersöks förhöjd biologisk nedbrytning genom att redogöra för de önskvärda (bio)kemiska reak- tionerna i marken, de parametrar som styr den biologiska nedbrytningen samt huruvida dessa parametrars inverkan har kunnat påvisas i tre stycken fallstu- dier där in situ-sanering utförts vid drivmedelsanläggningar. Studien kommer fram till ett antal primära (ursprungliga) variabler såsom föroreningen i fråga, jordtätheten och klimatet, samt ett antal sekundära (förändringsbara) variabler såsom oxidationsmedlet, mikroorganismerna, näringsämnena och markvattnet. Dessa presenterades sedan i en schematisk skiss som visar hur de växelverkar med parametrarna för optimal biologisk nedbrytning, vilka visade sig ha vissa optimala värden. Dessa konstaterades vara föroreningshalten (<5-10 viktprocent torr jord), pH-värdet (6-9), temperaturen (20-35◦C), vattenmättnaden (40-80%), syrehalten (> 2 500 viktprocent kolväten), C:N:P-kvoten (100:10:1) samt koncent- rationen mikroorganismer (> 103 CFU/ml). När de olika parametrarnas inverkan  i fallstudierna undersöktes kunde slutsatsen dras att det skulle behövas ytterliga- re data och mätningar vid varje sanering för att kunna garantera att parametrarna varit inom sina respektive optimala värden. / One of the many goals for a sustainable living and a healthy environment is the reduction of toxic substances in soil and groundwater. Within this ambit, one of the most common pollutants is aromatic hydrocarbons such as benzene, tolue- ne, ethylbenzene and xylenes (BTEX) which are spread from e.g. filling stations for fuel as they are constituents of petrol. These are volatile and can constitute a risk for humans and the environment as they percolate through the soil and groundwater resources as well as can exfiltrate from the ground to surrounding buildings and pollute the indoor air. Once these pollutants are present in the soil, the site needs to be remediated, something which is mainly done ex situ by exca- vating the polluted masses to be sent to a treatment facility. An alternative to this is in situ remediation where the pollution can be treated without being excavated and thus having a smaller impact on the environment.  In this report, one of these techniques called enhanced biodegradation was studied, which implies the application of oxidisers to faciliate microbial activities. It investigated (1) how this remediation technique works and what (bio)chemical reactions are desired in the soil; (2) what are the principal parameters that enable this remediation process and how do they interact with the surrounding factors, and (3) whether the impact of these parameters can be estimated in three case studies where this technique has been used. The three case studies were filling stations located in Sweden, having similar pollutants and geology, and two diffe- rent oxidisers had been used.  The study resulted in the identification of a number of primary (initial) varia- bles such as the pollutant characteristics, the soil density and the climate; as well as a number of secodnary (modifiable) variables such as the oxidiser, microorga- nisms, nutrients and soil moisture. These were then presented in a scheme which shows how their interactions with the parameters for optimal biodegradation. Each parameter was found to have a certain optimum such as the concentration of hydrocarbons (<5-10 mass percent of the dry soil) , pH value (6-9), tempe- rature (20-35◦C), soil water saturation (40-80%), oxygen concentration (> 2,500 mass percent of the hydrocarbons), C:N:P ratio (100:10:1) as well as concentration of microorganisms (> 103 CFU/ml). A negative correlation could be identified between the soil density and the oxygen concentration in the soil, as well as a po- sitive correlation between the soil water saturation in the and the soil moisture, alternatively additional water via irrigation. The impact of each parameter in the case studies of in situ remediation was assessed and the it could be concluded that they would need additional data and measurements for most parameters in order to guarantee that they are within the respective optima.
83

Commerce informel des hydrocarbures au Bénin / Informal trade of hydrocarbons in Benin

Diakite, Aboubakar 17 November 2016 (has links)
D’abord sur une échelle réduite puis sur une large échelle la contrebande du kpayo, essence et produits pétroliers occupent aujourd’hui un nombre de plus en plus grand de vendeurs, on estime que 100 000 personnes sont impliquées dans ce trafic du Nigeria au Bénin. Il revêt plusieurs aspects selon qu’il emprunte la route maritime, le fleuve ou la route. Ce transport génère un grand nombre de petits métiers que nous évoquons dans la thèse qu’il s’agisse d’apporter les bidons sur la plage, de transformer les scooters ou les camions. Plus que tout, cette activité suppose aussi un réseau souvent d’origine familiale, mais aussi des accointances avec du personnel des emplois régaliens de la République. Les recherches empiriques réalisées sur des territoires aussi variés et circonscrits que peuvent l’être une station-service, un village lacustre, un marché frontalier, un débarcadère, un entrepôt ont permis d’appréhender les conditions d’approvisionnement des contrebandiers, identifier les modalités d’acheminement des produits pétroliers vers le Bénin, saisir les stratégies de contournement des contrebandiers et les risques encourus tout au long de leur trajet, examiner les interactions entre les transporteurs et les forces de l’ordre à l’occasion du passage des barrières de contrôle, apprécier l’animation des marchés et enfin cerner le rôle des différents acteurs en présence. L’analyse des réseaux marchands, des parcours biographiques, des stratégies d’acteurs, des logiques d’accumulation et des rapports de l’économie informelle à la loi situe cette recherche au croisement de l’anthropologie économique, de la géographie du commerce, de la sociologie de la précarité, et de la sociologie politique. / First of all on a small scale, then further along, on a much larger scale, the kpayo trade which means smuggling of gas and other oil products from Nigeria to Bénin, depend on almost 100 000 persons living on this sale activity. This trade might be quite different if gas transported by means of ships on the sea, by the river, or by scooters or trucks on the road. This kind of informal trade gives way to different kinds of odd jobs we mention in the PHD: bringing the jerrycans to the beach, reshaping scooters and trucks in a garage. Most of all this illicit activity needs some kind of a kinship network and political pull among the police and customs officers of the Republic. Empirical research has been done in different fields such as a gas station, a seaside village, a market on the country border, a landing stage, a warehouse, it led to the comprehension of the way smugglers are supplied. I was thus able to understand the process by which gas was transported from Nigeria to the Republic of Bénin, and see all the byways the smugglers are used to take, and the risks taken all along the journey. I examined the interaction process between the racketeers and the police when they passed a checkpoint; see how the markets were busy, and last managed to see how the the different roles of subjects interact. The racketeers networks analysis, life stories, different action strategies, the way they accumulate and the study of informal economy related to law contribute in this PhD to an essay in economic- anthropology with geographic standpoints, and a sociological analysis of precarious lives and Big Shots.
84

Predi??o em modelos de tempo de falha acelerado com efeito aleat?rio para avalia??o de riscos de falha em po?os petrol?feros

Carvalho, Jo?o Batista 28 May 2010 (has links)
Made available in DSpace on 2015-03-03T15:28:31Z (GMT). No. of bitstreams: 1 JoaoBC_DISSERT_partes_autorizadas.pdf: 252147 bytes, checksum: e830f27faffa86c9087da28e43e699fd (MD5) Previous issue date: 2010-05-28 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / We considered prediction techniques based on models of accelerated failure time with random e ects for correlated survival data. Besides the bayesian approach through empirical Bayes estimator, we also discussed about the use of a classical predictor, the Empirical Best Linear Unbiased Predictor (EBLUP). In order to illustrate the use of these predictors, we considered applications on a real data set coming from the oil industry. More speci - cally, the data set involves the mean time between failure of petroleum-well equipments of the Bacia Potiguar. The goal of this study is to predict the risk/probability of failure in order to help a preventive maintenance program. The results show that both methods are suitable to predict future failures, providing good decisions in relation to employment and economy of resources for preventive maintenance. / Consideramos t?cnicas de predi??o baseadas em modelos de tempo de falha acelerado com efeito aleat?rio para dados de sobreviv?ncia correlacionados. Al?m do enfoque bayesiano atrav?s do Estimador de Bayes Emp?rico, tamb?m discutimos sobre o uso de um m?todo cl?ssico, o Melhor Preditor Linear N?o Viciado Emp?rico (EBLUP), nessa classe de modelos. Para ilustrar a utilidade desses m?todos, fazemos aplica??es a um conjunto de dados reais envolvendo tempos entre falhas de equipamentos de po?os de petr?leo da Bacia Potiguar. Neste contexto, o objetivo ? predizer os riscos/probabilidades de falha com a finalidade de subsidiar programas de manuten??o preventiva. Os resultados obtidos mostram que ambos os m?todos s?o adequados para prever falhas futuras, proporcionando boas decis?es em rela??o ao emprego e economia de recursos para manuten??o preventiva
85

Vliv změn spotřebních daní na spotřebu domácností / The impact of changes in excise tax on households expenditures

Martincová, Daniela January 2009 (has links)
This Thesis is concerned with examining the impact of changes in excise tax on households expenditures. It identifies and analyses the development of individual rates of excise tax and household spendings on selected goods in years 2000 -- 2009. The first chapter describes the various excise duties, the chapter two deals with the excise tax harmonization in European Union, in the third chapter defines the collection of data for analysis. The first, second and third part are prepared on the basis of the special literature (nonfiction), fourth (practical) part is processed and evaluated on the basis of the data obtained from the Czech Statistical Office and own calculations.
86

Optimalizace systémů EGR a vodního vstřikování u zážehového motoru / Optimization of EGR system and water injection for gasoline engine

Kertész, Tibor January 2020 (has links)
Naturally aspirated petrol engine, pressure losses, EGR, low-pressure EGR, water injection, power increasing, BSFC, GT-Power, thermodynamic model, engine knock
87

Studie odpočívky a velkokapacitního záchytného parkoviště pro TIR na dálnici D1 / The Study of the Parking Area on the Motorway D1

Šťastný, Radek January 2013 (has links)
The task of my diploma work is the study of the parking area on the motorway D1 near Vyškov. This place will be connected with the motorway D1 between the present exit Vyškov – West (226) and Vyškov – East (230/1) in the direction to Kroměříž. The parking area (the parking place, the petrol station, the restaurant) and the truckpark will be designed with the reason of the high intensity of cars and lorries on the motorway D1 and with the reason of the lack of the parking places for the lorries.

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