• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 26
  • 6
  • 2
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 44
  • 24
  • 14
  • 9
  • 8
  • 5
  • 4
  • 4
  • 3
  • 3
  • 3
  • 2
  • 2
  • 2
  • 2
  • 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.
41

Heat detection in precurser of tennis elbow and other joint injuries / Värmedetektion i förstadiet till tennisarmbåge och övriga ledskador

Paulsson, Olivia January 2020 (has links)
Background: Joint injuries are a complex matter. Due to the low blood flow to the tendons and ligaments, they take months or even years to heal; some fail to heal. This can be devastating for the elite athlete as well as for the labour worker or everyday person. Today, the devices that can detect an upcoming inflammation or injury, cost 15 000 US dollars and more. A cheaper technology would increase the access. This project is investigating the possibility to detect an upcoming inflammation through measuring the local skin temperature. Method: A model of an arm was built in Comsol Multiphysics, where a tennis elbow (lateral epicondylitis) was simulated through local temperature increase. Clinical tests were pursued on two healthy subjects, in order to gain knowledge on how the skin temperature behaves on healthy subjects. Results: At an internal temperature increase in the LE of 0.25 K, a temperature difference on the skin of 0.18 K was detected in the model. The clinical tests on healthy subjects indicated a correlation between the temperatures on and around the elbow joint. Discussion: The model results does not include any error sources, such as deviation in room temperature and factors affecting the subject´s body temperature, such as time of day, eating and exercising routines. The clinical tests show a pattern of the temperature distribution on and around the elbow joint, in healthy subjects. The fact that a pattern is present, is a presumption enabling to find deviations, caused by upcoming inflammation. Conclusion: The model is indicating that a local temperature increase in the LE is detectable at the skin surface. The clinical test indicates that the noise in the temperature data of a healthy person, is small enough to enable to detect a local temperature deviation. At a local skin temperature increase of more than 0.5 K, the results are indicating that the deviation is detectable. Analysing the model data, 0.5 K in skin temperature increase would mean a local temperature increase at the LE of approximately 0.7 K. This is before the stage of inflammation according to literature, which occurs at an increase of 1.5 to 2.2 K. Further studies would be interesting to make, in purpose of developing an affordable device that can detect if an inflammation is about to occur, and thereby enable the subject to stop the course. A prototype should be developed in order to make tests on more subjects. The equine industry is also a target group – the prototype may therefore be developed to fit both humans and horses. / Bakgrund: Ledskador är komplicerade. På grund av det låga blodflödet till senor och ligament, tar de månader eller år att läka; visa skador läker aldrig helt. Det här kan vara förödande för såväl elitatleter som arbetande och gemene man. Tekniker idag som kan detektera uppkommande inflammation eller skada, kostar 15 000 US dollar och mer. En billigare teknik skulle ha en större tillgänglighet. Det här projektet undersöker möjligheten att detektera en uppkommande inflammation genom att mäta den lokala skintemperaturen. Metod: En modell av en arm byggdes i Comsol Multiphysics, där en tennisarmbåge (lateral epikondylit) simulerades genom en lokal temperaturökning. Kliniska tester utfördes på två friska subjekt, för att skapa en bil av hur skintemperaturen varierar på friska personer. Resultat: Vid en inner temperaturökning om 0,25 K i LE, uppmättes en temperaturökning på huden om 0,18 K i modellen. De kliniska testerna på friska subjekt indikerade att en korrelation finns mellan temperaturerna på och runt armbågsleden. Diskussion: Resultat från modellen saknar felkällor, som exempelvis variation av rumstemperatur och andra faktorer som påverkar subjektets kroppstemperatur, som tid på dagen, mat- och träningsrutiner.De kliniska testerna uppvisar ett mönster av temperaturdistributionen hos friska subjekt på och runt armbågsleden. Att ett mönster finns, banar väg för att hitta avvikelser, som orsakas av uppkommande inflammation. Slutsats: Modellen indikerar att en lokal temperaturökning i LE är mätbar på huden. Det kliniska testet indikerar att bruset i temperaturdistributionen hos ett friskt subjekt, är litet nog för att möjliggöra detektion av en lokal temperaturavvikelse. Vid en lokal ökning av hudtemperatur med mer än 0,5 K, indikerar resultaten att avvikelsen är detekterbar. Vid analys av modellresultaten, innebär 0,5 K hudtemperatursökning en temperaturökningi LE om ungefär 0,7 K. Det är innan inflammation har brutit ut, som sker vid en ökning om 1,5 till 2,2 K. Vidare studier är intresssant att göra, i ändamål att utveckla en prisvärd produkt som kan detektera om en inflammation är på väg, och därigenom göra det möjligt för subjektet att stoppa förloppet. En prototyp behöver utvecklas för att kunna utföra tester på fler subjekt. Utöver människor, är hästindustrin en målgrupp – prototypen bör därför utvecklas för att passa båda grupperna.
42

Síntese por reação do TiFe nanoestruturado para o armazenamento de hidrogênio, a partir da moagem de alta energia de misturas de pós de TiH2 e Fe / Reaction synthesis of nanostructured TiFe for hydrogen storage from high-energy ball milling of TiH2 and Fe powders mixtures

FALCAO, RAILSON B. 10 March 2017 (has links)
Submitted by Mery Piedad Zamudio Igami (mery@ipen.br) on 2017-03-10T16:23:34Z No. of bitstreams: 0 / Made available in DSpace on 2017-03-10T16:23:34Z (GMT). No. of bitstreams: 0 / Neste trabalho investigou-se a obtenção do composto TiFe a partir da moagem de alta energia de misturas de pós de TiH2 e Fe, seguida de aquecimento sob vácuo para a reação de síntese. No lugar do Ti, o TiH2 foi escolhido como precursor em razão de sua fragilidade, benéfica para a diminuição da aderência dos pós ao ferramental de moagem. Foram preparados dois lotes de misturas obedecendo-se a relação Ti:Fe de 50:50 e 56:44. Ambos foram processados em um moinho do tipo planetário por tempos que variaram de 5 até 40 horas, sob atmosfera de argônio de elevada pureza. Em todos os experimentos foram mantidos constantes a velocidade de rotação do prato do moinho, a quantidade de amostra, o diâmetro e o número de bolas. As amostras moídas foram caracterizadas por calorimetria exploratória diferencial (DSC), termogravimetria (TG), microscopia eletrônica de varredura (MEV), difração de raios X (DRX) e fluorescência de raios X por dispersão de energia (EDXRF). Apenas TiH2 e Fe foram observados nas amostras moídas, com um grau crescente de mistura em função do tempo de moagem. O composto TiFe nanoestruturado (12,5 a 21,4nm) foi obtido de forma majoritária em todas as amostras após a reação de síntese promovida pelo tratamento térmico a 600ºC (873K). As amostras reagidas foram caracterizadas por microscopia eletrônica de transmissão (MET) e DRX. Um equipamento do tipo Sievert, operando sob um fluxo constante (modo dinâmico), foi utilizado para levantar as curvas termodinâmicas de absorção e dessorção de hidrogênio. Todas as amostras absorveram hidrogênio à temperatura ambiente (~298K) sem a necessidade de ciclos térmicos de ativação. Os melhores resultados foram obtidos com as amostras moídas por 25 e 40 horas, de composição não estequiométrica 56:44. Tais amostras absorveram e dessorveram hidrogênio à temperatura ambiente, sob os platôs de aproximadamente 6,4 e 2,2bar (~0,6 e 0,2MPa), respectivamente. A capacidade máxima de armazenamento foi de 1,06% em massa de hidrogênio (H:M~0,546), sob pressão de até 11bar (1,1MPa), com reversão de até 1,085% em massa de hidrogênio (H:M~0,559), sob pressão de até 1bar (0,1MPa). Estas amostras também apresentaram maior cinética de absorção e dessorção de hidrogênio com fluxos de 1,23 (25h) e 2,86cm3/g.min. (40h). Tais resultados são atribuídos à variação composicional da fase TiFe e à maior quantidade de TiH2 livre. / Tese (Doutorado em Tecnologia Nuclear ) / IPEN/D / Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP
43

選民投票行為與政黨輪替:台灣及墨西哥二000年總統選舉之比較

許勝懋, Hsu, Shen Mao Unknown Date (has links)
民主政治運作過程中,當主政者無法滿足選民需求時,選民理所當然會以選票表達其自主性,找一個更符合其需求的政黨作為治理國家的代理人(總統)。政黨輪替就成為選民選擇最佳代理人的手段。政黨輪替的本身,就是一種權力交替與權力制衡,特別是在執政黨交不出政績的時候,政黨輪替就是一個民主的制裁機制,更是一個國家走向民主政治的重要指標。 影響選民決定更換治國代理人的投票抉擇因素,主要有政黨因素、候選人因素,抑或是議題因素。無論在美國與其他西方國家,甚至在已開發或開發中國家都已經獲得印證。當選民利用參考標的進行投票,選民的總統選舉投票結果將會匯集成決定最後政權誰屬。把票投給執政黨的候選人,還是把票投給在野政黨的候選人,不僅攸關個別政黨與候選人的選舉成敗,而且還影響到統治權力歸屬,甚至會牽動政黨輪替執政的可能性,其重要性,不言而諭。也正因如此,政治學者亟思理出選舉各黨勢力消長的軌跡,試圖描繪出選民投票抉擇的決定如何影響政治權力的轉移。 本文的目的,是研究選民投票抉擇的一般原則應用到總統選舉結果「政權轉移」或「政黨輪替」這個重要的主題,針對可能造成多數選民由投票支持原有執政黨轉而投票支持原有最大在野黨取得執政權的成因進行討論。台灣與墨西哥這兩個長久以來一黨威權獨大的政權,卻同時在西元二○○○年發生政黨輪替的現象。有關選民選擇支持原有最大在野黨取得執政權的成因,主要從三個面向進行討論: 首先,政黨認同因素,選民政黨認同發生改變所引發的政黨認同重組現象,讓原本獲得多數選民支持的執政黨,因為政黨重組的因素變成僅吸引少數選民支持的在野黨;相反地,原本僅有少數選民支持的在野黨,因為政黨重組的關係變成吸引多數選民支持的執政黨。其次,候選人因素,候選人人格特質、能力與對候選人情感溫度等因素,讓多數選民受候選人這個短期因素所影響而選擇支持最大在野黨執政。最後,議題因素,選民的展望性評價與重大議題中的改革議題,因選民希冀更換原有執政黨,由最大反對黨執政,能夠改變趨於日益不振的經濟現況,並透過大幅改革能改變舊政府的缺失,期望新政府能夠振衰起弊。 / In the democratic operation process, when the director is unable meet the citizens need, the citizen would express their autonomy by votes. Looking for one (or political party) who could conform to the citizens demand takes the government (president) of this country. Party rotation is a democratic sanction mechanism. That is an important indicator for country achieving the democracy. There are some factors must be considered while establishing voting behavior models in the turnover elections. There mainly are the party identification or party preference, the candidate image, and policy orientation. My thesis finds that party realignment is the key variable for 2000 Mexican presidential election, but 2000 Taiwan presidential is not. Candidate image or candidate personality centers on competence, likeability, honesty, reliability, and understanding people’s needs. Candidate evaluation refers to an overall assessment of the candidates: it is measured by way of “feeling thermometers”. My study found that candidate image is an important factor in determining Mexican and Taiwan voters choosing the opposition party candidate for a new president. The results shows that the policy issues, including prospective economic voting and the salience issue of change influence people’s voting choices.
44

Temperature Based Estimation of the Time-Resolved Massflux of ICE Exhaust Gas Flow

Khedekar, Mayur January 2021 (has links)
The aim ofthe study was to provideinformation and experience gained with fine wire thermocouples (TCs)or resistance wire thermometers (RWTs) temperature signals to estimate the timeresolved heat transfercoefficient. Constant current method was assumed in the study and medium used in this study was air. Here the heat balance equation has been described, different Nucorrelations and further discusses potential hurdles and difficulties one may encounter while calculating heat transfer coefficient. As asolution, the use of an appropriate heatbalance equation and lowpass filter was suggested as this provides a more accurate fitting. The investigation was carried out for Reynolds number (Re) 103 to 107 and Prandlt number (Pr) 0.734. The impact of the Re and Pr on the Nusselts number (Nu) around a cylinder was represented and all the results were compared with GT-POWER engine simulation software. / Syftet med studien var att tillhandahålla information och erfarenhet från fina trådtermoelement (TC) eller motståndstrådstermometrar (RWT) temperatursignaler för att uppskatta den tidsupplösta värmeöverföringskoefficienten. Metoden med konstant flöde antogs i studien och mediet som användes i denna studie var luft. Här har värmebalansekvationen beskrivits, olika Nu-korrelationer och diskuterat ytterligare potentiella hinder och svårigheter man kan stöta på vid beräkning av värmeöverföringskoefficienten. Som en lösning föreslogs användning av en lämplig värmebalansekvation och lågpassfilter eftersom detta ger en mer exaktpassform. Undersökningen genomfördes för Reynoldsnummer (Re) 103 till 107 och Prandlt nummer (Pr) 0,734. Effekten av Re och Pr på Nusselts-numret (Nu) runt en cylinder representerades och alla resultat jämfördes med GT-POWER-motorns simuleringsprogram.

Page generated in 0.1248 seconds