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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.
131

ALTERNATE POWER AND ENERGY STORAGE/REUSE FOR DRILLING RIGS: REDUCED COST AND LOWER EMISSIONS PROVIDE LOWER FOOTPRINT FOR DRILLING OPERATIONS

Verma, Ankit 2009 May 1900 (has links)
Diesel engines operating the rig pose the problems of low efficiency and large amount of emissions. In addition the rig power requirements vary a lot with time and ongoing operation. Therefore it is in the best interest of operators to research on alternate drilling energy sources which can make entire drilling process economic and environmentally friendly. One of the major ways to reduce the footprint of drilling operations is to provide more efficient power sources for drilling operations. There are various sources of alternate energy storage/reuse. A quantitative comparison of physical size and economics shows that rigs powered by the electrical grid can provide lower cost operations, emit fewer emissions, are quieter, and have a smaller surface footprint than conventional diesel powered drilling. This thesis describes a study to evaluate the feasibility of adopting technology to reduce the size of the power generating equipment on drilling rigs and to provide ?peak shaving? energy through the new energy generating and energy storage devices such as flywheels. An energy audit was conducted on a new generation light weight Huisman LOC 250 rig drilling in South Texas to gather comprehensive time stamped drilling data. A study of emissions while drilling operation was also conducted during the audit. The data was analyzed using MATLAB and compared to a theoretical energy audit. The study showed that it is possible to remove peaks of rig power requirement by a flywheel kinetic energy recovery and storage (KERS) system and that linking to the electrical grid would supply sufficient power to operate the rig normally. Both the link to the grid and the KERS system would fit within a standard ISO container. A cost benefit analysis of the containerized system to transfer grid power to a rig, coupled with the KERS indicated that such a design had the potential to save more than $10,000 per week of drilling operations with significantly lower emissions, quieter operation, and smaller size well pad.
132

IMPROVED DESIGN FOR HYDRAULIC VALVE AND HYDRAULIC VALVE TESTING RIGIMPROVED DESIGN FOR HYDRAULIC VALVEAND HYDRAULIC VALVE TESTING RIG : DESIGN AND PRODUCT DEVELOPMENT

Markonda, Raviteja, Vasava, Pratikchandra J January 2014 (has links)
The hydraulic testing rig is a machine that is used to test the hydraulic valves.The present testing rigs are used according to only some particular specification, but in ourproject we have developed a process and implemented the idea for building a UniversalHydraulic Testing Rig which can be able to test any kind of valves with simple adjustments.The hydraulic valves are mainly designed to carry out the flow of the hydraulic fluid with thedesired pressures. But it is observed that there are many pressure losses in the flow whichleads to the unreached flow pressures as expected. In a pre-project to this work a patentedhydraulic valve designed to improve the flow pressure of the hydraulic fluid. The main targetof the design of the valve is to decrease pressure losses and give maximum output from theother end of the valve. The Hydraulic Testing Rig is designed with the help of design softwareand flow simulation process helps to know about the pressure flow from inlet to outlet ofthe valve. After the testing of the design, the valve is tested on the new universal hydraulictest rig developed in this project. With the future use of the hydraulic valve test rig, thesimilarities and variations are observed from both the simulations done and test results canbe compared to optimize the valve design further. With the combination of hydraulic test rigand redesign hydraulic valve we will provide and experimental test rig possibility to bringthe better and maximum design that could be attained reducing the energy losses in hydraulicvalve designs.
133

Konstruktion av en spegelrigg för stereoskopisk 3D i lågbudgetprojekt : En undersökning kring möjligheter och begränsningar med att konstruera en egen lättviktsrigg för stereoskopisk 3D-film i lågbudgetprojekt.

Karlsson, David, Korsgren, Tom January 2016 (has links)
Att filma i 3D är en process som kräver mycket kunskap, tid och teknisk utrustning. För att fullständigt behärska detta fält krävs dessutom omfattande praktisk erfarenhet. Denna erfarenhet kan vara svår att få eftersom den ekonomiska investeringen för att filma i 3D ofta är stor. I denna uppsats visar vi att det är möjligt att konstruera en egen 3D-rigg och att filma med vanliga konsumentkameror för att skapa 3D-film. Uppsatsen visar på de begränsningar och svårigheter man stöter på då man bygger sin egen rigg och diskuterar den ekonomiska besparing man kan göra i jämförelse med kommersiella lösningar. Att bygga en egen rigg är tidskrävande och oftast inte att rekommendera i professionella sammanhang. För indieproduktioner, hobby-fotografer eller om man har väldigt specifika krav som ej uppfylls av tillgängliga kommersiella 3D-riggar kan det dock vara motiverat att konstruera sin egen rigg. Kunskapen som uppsatsen redovisar möjliggör ett resonemang för hur bildkvalitet, funktion och ekonomi kan ställas mot varandra i de avvägningar man ställs inför i konstruktionen av en spegelrigg för att filma i 3D.
134

Projeto de uma perfuratriz multifuncional para execução de estacas e desenvolvimento de um ensaio de campo que utiliza o sistema de monitoração eletrônica da perfuratriz / Design of a multifunctional drilling rig for the construction of piles and development of a field test using its electronic monitoring system

Gilmar Wilian Barreto 14 November 2014 (has links)
Esta tese apresenta, o projeto de uma perfuratriz que permite a execução de cinco tipos de fundação profunda, e o desenvolvimento de um ensaio de campo que possibilita avaliar as resistências por atrito lateral desenvolvidas entre o instrumento envolvido pelo solo escavado e o terreno natural. A perfuratriz foi projetada para executar estacas dos tipos hélice contínua monitorada, escavadas com trado mecânico, hélice segmentada monitorada, raiz e hollow-auger. As estacas dos tipos hélice contínua monitorada e as escavadas com trado mecânico são muito utilizadas no Brasil; as estacas raiz e hollow-auger são utilizadas em situações especiais e a estaca hélice segmentada monitorada é mais recente, mas sua aplicação tem tido um crescimento importante nos últimos dez anos. Para a perfuratriz multifuncional são apresentados cálculos e desenhos básicos dos principais conjuntos. Para a nova investigação de campo, denominada FDT - Full Displacement Test, é apresentado um desenvolvimento teórico com base no princípio universal da conservação de energia que, em termos práticos, resulta na obtenção da parcela de atrito lateral, denominado atrito lateral unitário equivalente (fse). Os resultados obtidos a partir dos dados aquisitados pelo sistema de monitoramento eletrônico da perfuratriz apresentaram-se concordantes entre si, indicando a possibilidade de praticamente se conseguir a repetibilidade do ensaio. Entre os diversos ensaios realizados, foi dada ênfase aos ensaios realizados no campo experimental de Fundações e Geotecnia da Faculdade de Engenharia Agrícola FEAGRI, da Universidade de Campinas - UNICAMP e foram feitas correlações com as resistências obtidas nas provas de carga estáticas realizadas no local por Albuquerque (2001), a partir dos ajustes feitos para o nível instrumentado na profundidade de 11,70 m para o qual foi determinado um fator (G2), para cada tipo de estaca ensaiada (escavada, hélice contínua e ômega). A partir dos ajustes feitos para o nível 11,70 m foram feitas previsões de capacidade de carga por atrito lateral para os outros níveis instrumentados (5,00 m; 11,10 m e 12,00 m), sendo que os resultados apresentaram-se concordantes. / This thesis presents the design of a drilling rig that allows the execution of five types of deep foundation, and the development of a field test that allows measuring the skin friction resistance developed between the instrument involved by the excavated ground and the natural soil. The drilling rig was designed to make continuous flight auger, bored pile, continuous flight auger with segmented auger, root pile and hollow-auger pile. The continuous flight auger and bored piles are widely used in Brazil; the root pile and hollow-auger pile are used for in special conditions, and the continuous flight auger with segmented auger, is although more recent, but its application has had increased application grown in over the last ten years. For the multifunctional drilling rig, calculations and basic designs of the main sets are presented. For the new field test denominated FDT - Full Displacement Test, a theoretical development based on the universal principle of energy conservation was made carried out resulting and the result, in practical terms, was to obtain in the attainment of the skin friction defined in this thesis as equivalent unit skin friction (fse). The results obtained from the data acquired by the electronic monitoring system of drilling rigs were consistent among themselves, indicating the possibility of practically achieve the repeatability of the test. Among the various tests performed, emphasis was given to tests in the experimental field of foundations and geotechnics, of the College of Agricultural Engineering FEAGRI, Campinas University UNICAMP, and were correlated to the skin friction resistance obtained from the static load tests performed on site by Albuquerque (2001), based on the adjustments done to the instrumented level depth of 11.70 m, for which a factor (G2) was given in each type tested (bored, C.F.A and omega). From the adjustments made to the 11,70 m level, load-bearing capacity of skin friction predictions were made for other instrumented levels (5.00 m; 11.10 m and 12.00 m) presenting consistent results.
135

Multi-axial fracture behaviour of notched carbon-fibre/epoxy laminates

Tan, Julian Lip Yi January 2015 (has links)
Carbon-fibre reinforced polymer (CFRP) laminates are widely used in various engineering applications, such as in race cars and aircrafts, because they are light, stiff and strong. They commonly contain stress raisers in the form of holes and notches (for mechanical joining methods, routing of pipes and cables etc.) and are also often subjected to complex combined multi-axial stress conditions during service. Yet their notched multi-axial fracture behaviour remains largely unexplored. This is the main contribution of the thesis. First, a novel loading fixture for applying a wide range of in-plane loading modes is developed based on the popular Arcan’s method. Termed the ‘modified Arcan rig’, it utilises friction gripping to transfer loads into tabbed specimens. This loading fixture is used to test centre-notched multi-directional CFRP laminates under different combinations of tension and shear stresses. Together with penetrant-enhanced X-ray CT and laminate de-ply, the fracture behaviour of quasi-isotropic CFRP specimens is investigated for the following loading modes: pure tension, pure compression, in-plane shear, and combined tension and shear. Two notch geometries (sharp notch and circular hole) are investigated to allow for an assessment of the role of stress concentration upon strength and damage development to be performed. Three distinct fracture modes are observed in a tensile/compressive-shear stress space (termed Mechanism A, Mechanism B and Mechanism C). It is observed that quasi-isotropic specimens with a central sharp notch are consistently stronger than equivalent specimens with a central circular hole (for all stress states investigated). An underlying micromechanical explanation concerning the effects of damage upon strength is proposed. Second, a finite element (FE) model is developed using the commercial FE program, Abaqus FEA to simulate the observed progressive damage and failure in the quasi-isotropic specimens. The FE model employs independent material property data as inputs. Overall, good correlation between the simulations and the experiments is obtained, validating the FE strategy. The capabilities of the model are extended to predict the notched fracture behaviour of the specimens under combined compression and shear loading, for which experimental work has not been done by the author, but for which literature data exists. Finally, the effect of laminate lay-up upon the notched multi-axial fracture behaviour of the CFRP specimens is explored by considering a 0° ply-dominated lay-up, a ±45° ply-dominated lay-up and a cross-ply lay-up, alongside the quasi-isotropic lay-up. Experiments reveal that all lay-ups exhibit Mechanisms A, B and C. However, the extent of damage in each Mechanism as well as the regime in which each Mechanism operates in (in the failure envelopes) strongly depend on the lay-up of the specimen. As expected, the tensile strengths and compressive strengths increase with the proportion of 0° plies. Surprisingly, the shear strengths do not scale with the proportion of ±45° plies; the specimen geometry and material orthotropy are attributed as reasons for this. In contrast to the case of the quasi-isotropic lay-up, the extent of subcritical damage induced by the circular hole is not always lower than that induced by the sharp notch for the other lay-ups. The difference in the extent of damage between both notch geometries is reflected in the notched strengths of the lay-up in question. These experimental observations are adequately predicted by the FE strategy, which further validates it as a reliable predictive tool for composite fracture.
136

Investigation of an Oncolytic MeV Cell-Cell Fusion Phenomenon Induced by an siRNA

Barkley, Russell 02 December 2020 (has links)
Oncolytic measles virus is a promising cancer therapeutic in clinical trials which possesses multiple characteristics that are advantageous over traditional therapies. Currently, clinical oncolytic measles virus vectors are unmodified or express reporter transgenes that benefit its therapeutic efficacy. The next phase in its development will see genetically engineered vectors encoding transgenes that enhance its antineoplastic effects. To this end, preclinical research has focused on studying novel transgenes which favour viral replication, cytotoxicity, and the anti-cancer immune response. We sought to encode artificial micoRNAs targeting RIG-I as a strategy to interfere with innate immunity. Silencing RIG-I with multiple siRNAs yielded one which promotes measles virus syncytia formation through a mechanism that appears to be independent of RIG-I. The mechanism caused by the siRNA leads to enhanced measles virus cell-cell fusion and has peculiar characteristics which are not fully understood.
137

Realisation and evaluation of a start-stop journal bearing test-rig / Realisering och utvärdering av en glidlagerrigg för start-stop-provning

Gralde, Marcus, Sölvason, Tómas Rúnar January 2014 (has links)
While there has been substantial body of work in the field of journal bearing research, much of it is today theoretical or simulated due to today’s computing power. Scania produces experimental data from motor testing, but these are expensive and time consuming. Furthermore there is a difficulty in keeping a sufficiently controlled environment, which at times makes it hard to draw conclusions from testing results. They therefore wish to develop a test-rig which can evaluate friction and wear in journal bearings. This thesis is a continuation of a project in the course Advanced Machine Design given at KTH Royal Institute of Technology. During this thesis the test-rig has been manufactured, built, and evaluated. Furthermore software for the test-rig was developed. Information on journal bearings, risk assessment and signal noise handling were sought. Mechanical development was done with Autodesk Inventor, while Matlab was used for software development. Factorial design was utilised when designing tests and compared to a simple theoretical model. Test results showed promising results for Stribeck curve-producing tests, with good resemblance to known frictional values and trends. Furthermore the test-rig showed good repeatability for replicated tests and produced wear on the bearing shells used. During a prolonged test, the shaft and support-bearings were damaged and requires servicing to be in an operational state. The test-rig requires to be further verified, but the tests that were carried out showed valuable and reliable information on wear and frictional values. Keywords: journal bearing, hydrodynamic lubrication, wear, start-stop, test-rig / Även om en betydande mängd forskning inom glidlager och fullfilmslager har genomförts så är med dagens datorkapacitet en stor del av resultaten numera teoretiska eller simulerade. Medan Scania producerar experimentella resultat, så är dessa dyra och tidskrävande. Vidare är det ibland svårt att hålla en tillräckligt kontrollerad miljö för att dra slutsatser från proverna. Med en dedikerad testrigg som kan tillförlitliga resultat tas fram billigare och snabbare. Detta examensarbete är en fortsättning av kursen Avancerad Maskinkonstruktion som ges vid Kungliga Tekniska Högskolan. Under detta examensarbete har testriggen tillverkats, byggts och utvärderats. Vidare har programvara för testriggen utvecklats. Informationssökning gjordes på glidlager, fullfilmslager, riskbedömning och signalbrushantering. Mekanisk utveckling har gjorts i Autodesk Inventor, medan Matlab användes för mjukvaruutveckling. Faktorial design har nyttjats vid utformningen av tester. Resultaten jämfördes med en enkel teoretisk modell. Testresultaten visade lovade resultat för Stribeck kurva-producerande tester, med god likhet till kända friktionsvärden och trender. Testriggen visade god reproducerbarhet vid replikerade tester. Testriggen producerar slitage på samtliga testade lagerytor. Under ett längre test så har axel och stödlager skadats, varför service behövs för att testriggen skall vara i brukbart skick. Testriggen kräver ytterligare verifiering, men resultaten från de prov som genomförts visar att test-riggen ger värdefull och tillförlitlig information om slitage och friktion kunna utrönas. Nyckelord: glidlager, hydrodynamisk smörjfilm, nötning, start-stop, testrigg
138

Det är inte talangen som avgör, utan våra val : En kvalitativ studie om varför unga, talangfulla flickor slutar spela handboll i Sverige

Kulju, Lotta January 2021 (has links)
De flesta elitidrottskarriärer har sin startgrop i föreningsidrotten och närmare 90 procent av alla barn och ungdomar i Sverige har någon gång under sin uppväxt varit medlemmar i en idrottsförening. För de flesta barn innebär föreningsidrotten en positiv miljö där alla barn och ungdomar ska få möjlighet att vara med och delta på lika villkor – tills de plötsligt inte får det längre. Leken förvandlas till allvar och idrotten handlar nu i allt större omfattning om selektion, talangidentifikation och uttagningar. Genom att bli antagen till ett idrottsgymnasium har man goda möjligheter att kombinera sina studier med idrotten, vilket är en viktig grund i den svenska idrottsmodellen. Idrottsutbildningen har aldrig varit så varierad som idag, och det är vanligt att tänka att de idrottare som blivit antagna till idrottsgymnasium automatiskt kommer gå hela vägen. Trots det finns det idrottande ungdomar som väljer att avsluta sina karriärer efter tre år på ett idrottsgymnasium. Syftet med studien var att skapa en större förståelse kring avhopp bland unga talanger inom svensk handboll, som under tre års tid gått på ett handbollsgymnasium. Vidare undersöktes hur spelarna upplevde både tiden på handbollsgymnasiet och den egna avslutsprocessen, och vad handbollsföreningar och handbollsgymnasier kan jobba med för att få fler handbollsspelare att stanna kvar inom idrotten. Kvalitativa intervjuer genomfördes med åtta stycken före detta handbollsspelare i åldrarna 18-23. En semistrukturerad intervjuguide konstruerades och samtliga intervjuer spelades in, transkriberades och analyserades. Huvudresultaten i studien visar att avhopp sällan beror på endast en orsak, och att största delen av avhoppen berodde på avsaknaden av ett socialt stöd, brist på motivation, tränarna, prestationsångest eller en kombination av flera faktorer. Spelarnas avslutsprocesser analyserades med hjälp av Ebaughs teori om avslut. Vidare diskuterades idrottsmiljöns betydelse för unga handbollsspelare och att ett socialt stöd bör finnas till hands för spelarna på handbollsgymnasierna i en större omfattning. Även en god kommunikation mellan handbollsgymnasiet och klubblaget ansågs vara av stor betydelse för spelarna. / Most elite sports careers have their start in sport clubs, and approximately 90 percent of all kids and adolescences in Sweden have, during their childhood, been members in a sport club. For most kids, the sport clubs imply a positive environment where all children should have an opportunity to participate on equal terms – until they suddenly don’t anymore. The play turns to seriousness and is now more and more becoming a matter of selection and talent identification. By being selected to a sport school the athletes have a good chance of combining the studies with their sports, which is an important motive in the Swedish sports model. The sports education has never been as varied as it is today, and it’s common to think that the athletes who have been selected to a sport school automatically will reach the top. Despite this, there are athletic adolescences who choose to quit their career after three years in a sport school. The purpose of this study was to investigate why young, talented handball players quit their career after three years in a sport school. Furthermore, it is investigated how the players experienced both their time at the sport school and their own disengagement process, and what handball associations should work with in order to get more young, talented handball players to stay in the sports. Qualitative interviews were conducted with eight former talented handball players in the ages 18-22, all of whom went to a sport school for three years. A semi-structured interview guide was constructed and all of the interviews were recorded, transcribed and analyzed. The main findings of the study show that drop-outs rarely depends on one single factor, and that most of the drop-outs for the adolescences’ in this study happened due to lack of social support, amotivation, the coaches, performance anxiety or a mix of multiple factors. The players drop-out process was analyzed with Ebaughs’ disengagement process. Furthermore, the impact of the sports environment for young, talented handball players and the importance of a social support for them is discussed and shows that these factors should be available for the players in sport schools to a greater extent. A good communication between the sport school and the players clubs was also considered important according to the former players.
139

Generation of hepatocellular cell line capable of supporting the full replication cycle of Hepatitis B Virus / B型肝炎ウイルスの完全複製を支持する肝細胞株の樹立

Yao, Wan-Ling 23 May 2017 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(生命科学) / 甲第20592号 / 生博第380号 / 新制||生||50(附属図書館) / 京都大学大学院生命科学研究科統合生命科学専攻 / (主査)教授 藤田 尚志, 教授 朝長 啓造, 教授 豊島 文子 / 学位規則第4条第1項該当 / Doctor of Philosophy in Life Sciences / Kyoto University / DFAM
140

Framtagning av testrigg för att testa regnerosion på vindturbinblad / Development of a test rig for testing rain erosion on wind turbine blades

Arvidsson Lindbäck, Nils, Johansson, David January 2023 (has links)
Bakgrunden till projektet är problem med kanterosion av turbinblad inom vindkraftverks- industrin. Det är ett fenomen som uppstår när turbinblad roterar i höga hastigheter och träffar partiklar, främst vattendroppar i regn. Denna erosion skadar turbinbladen, vilket både minskar vindkraftverkens effektivitet och sprider partiklar i den lokala miljön. För att både undersöka detta fenomen och ge möjlighet att utvärdera olika materials motståndskraft mot erosion ska en testrigg tas fram. Utöver detta ska testriggen även möjliggöra uppsamling av partiklar för vidare forskning kring deras effekt på miljön. Som utgångspunkt används en tribometer med rotationsmekanism från ett föregående maskinkonstruktionsprojekt på KTH. Ombyggnationen av denna avgränsas till att endast genomföras digitalt med hjälp av CAD för att hålla mängden arbete till en rimlig nivå. Förutom CAD har arbetet även inkluderat kravspecifikationer, beräkningar i MATLAB, FEA-analyser och kostnadskalkyler. Resultatet är en digitalt styrd testrigg med tillhörande komponentlista och instruktioner för tillverkning och genomförande. Inköpskostnad för ombyggnationen uppskattas till 28 000 kr. Riggen för en cylindrisk provbit genom ett artificiellt regn i hög hastighet, vilket resulterar i en accelererad nötningsprocess. Under testets gång dokumenteras erosionen visuellt med hjälp av en kamera och efter testet kan mängden förlorat material mätas i vikt och partiklar samlas upp. Flera andra parametrar dokumenteras automatiskt under testets gång för att ge en mer detaljerad bild av processen och data för undersökningar av repeterbarhet. Slutligen konstateras att testriggen uppnår alla krav ställda på den förutom att den inte har en nödbroms. Avsaknaden av nödbroms diskuteras och det leder till slutsatsen att testriggen, även utan nödbroms, är fullt fungerande, enkel och säker att använda. / The background for this project is a problem in the wind turbine industry, namely leading edge erosion of turbine blades. This occurs when wind turbine blades rotate at high speeds and collide with particles, mainly water drops in rain. This erosion damages the turbine blades, reducing the efficiency of the wind turbines and releasing particles into the local environment. To investigate this phenomenon and evaluate the durability of different materials, a test rig is to be developed. In addition, the test rig will enable the collection of particles to facilitate further research into their environmental impact. A tribometer with a rotation mechanism from a previous project at KTH serves as the starting point. The reconstruction of this tribometer is limited to a digital implementation using CAD to keep the amount of work at an appropriate level. In addition to CAD, the work has also included requirements specifications, calculations in MATLAB, FEA, and cost estimates. The result is a digitally controlled test rig with an accompanying component list and instructions for manufacturing and implementation. The estimated purchase cost for the reconstruction is 28,000 SEK. The rig tests a cylindrical sample by propelling it at high speed through artificial rain, resulting in an accelerated wear process. The erosion is visually documented using a camera during the test. Afterwards the amount of lost material can be measured by weight and the particles collected. Several other parameters are automatically recorded during the test to provide a more detailed picture of the process and data for investigations into repeatability. Finally, it is concluded that the test rig meets all its requirements except for the absence of an emergency brake. The absence of an emergency brake is discussed, leading to the conclusion that despite missing an emergency brake, the test rig is fully functional, easy to use, and safe.

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