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[en] ULTRA HIGH CYCLE FATIGUE BEHAVIOR OF THE DIN 34CRNIMO6 STEEL / [pt] COMPORTAMENTO DO AÇO DIN 34CRNIMO6 EM FADIGA DE ALTÍSSIMO CICLOMARIA CLARA CARVALHO TEIXEIRA 04 January 2019 (has links)
[pt] Estudos recentes têm mostrado que para muitos materiais de Engenharia não existe um limite de fadiga. Numa análise convencional, se admite uma vida infinita em fadiga de alto ciclo quando o material atinge 10(6) - 10(7) ciclos sem a incidência de falhas. Entretanto, em função do desenvolvimento tecnológico atual, a vida-fadiga de inúmeros componentes mecânicos e estruturais pode ultrapassar a fronteira da fadiga de alto ciclo, fazendo com que a avaliação do comportamento em fadiga de altíssimo ciclo (10(7) – 10(12)), tenha se tornado extremamente importante para projetos, por ter estabelecido que uma tensão limite de fadiga não existe em muitos casos. Pesquisas recentes demonstram que a maioria dos materiais, incluindo ligas ferrosas, apresentam falhas em até 10(10) ciclos, com um decréscimo contínuo do limite de fadiga após 10(6) ciclos, o que torna a resistência à fadiga associada com um número de ciclos mais importante do que o próprio limite de fadiga. No regime de altíssimo ciclo de fadiga as trincas se iniciam a partir de defeitos internos do material, como inclusões, gerando mecanismos de iniciação de trincas caraterísticos das superfícies de fratura, tais como olho de peixe (fish-eye), ODA (Optically Dark Area) e FGA (Fine Granular Area). Neste estudo foram usinados corpos de prova do aço DIN 34CrNiMo6, que foram ensaiados entre 10(6) e 10(9) ciclos, sob fadiga ultrassônica do tipo tração-compressão, com frequência de 20 kHz e razão de carregamento -1. Os resultados mostraram que o material tem uma tendência maior a vida-fadiga sob valores baixos de tensão e na superfície de fratura de alguns corpos de prova formação de fish-eye. / [en] Recent studies have shown that for many engineering materials there is no fatigue limit. In a conventional analysis, infinite life in high cycle fatigue is allowed when the material reaches 10(6) - 10(7) cycles without the occurrence of failures. However, due to the current technological development, the fatigue life of several mechanical and structural components can exceed the boundary of high cycle fatigue, making the evaluation of ultra high cyle fatigue behavior (10(7)-10(12)), or fatigue of very high cycle, has become extremely important for projects, because it has established that a stress of fatigue limit does not exist in many cases. Current research has shown that most materials, including ferrous alloys, exhibit failures in up to 10(9) cycles, with a continuous decrease in the fatigue limit after 10(6) cycles, which makes strength fatigue associated with a number of cycles most important than own fatigue limit. In the very high fatigue cycles regime, cracks start from internal defects of the material, such as inclusions, generating a feature mechanisms of crack initiation on the fracture surfaces, such as fish-eye, ODA (Optically Dark Area) and Fine Granular Area (FGA). This study, specimens of DIN 34CrNiMo6 steel were machined and were tested between 10(6) and 10(9) cycles, under ultrasonic fatigue, with a frequency of 20 kHz and a loading ratio of -1. The results showed that the material has a tendency to fatigue life under low stress values and in some fracture sufaces of the specimens the fish-eye formation.
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日本對中共政府開發援助之探討傅國華 Unknown Date (has links)
過去許多研究日本經濟援助,將重點放在日本援助體制──四省廳制 ,甚至直接分析通產省(Ministry of International Trade and Industry, MITI)及外務省在對外援助方面的不同立場, 亦即研究主題是傾向於外交政策形成的層面進行分析。但事實上若單從政策面分析可能無法瞭解整個援助的全貌,有見樹不見林之憾。因此,本論文希望藉由新現實主義與新自由制度主義建立分析架構,而進一步分析日本經濟援助的演變。
第二章先由新現實主義為首建立基本的分析架構。根據華爾茲(Kenneth N. Waltz)的論點,一國的外交政策是受國際結構的因素所影響。而國際結構是由國家間不同的能力分配所促成,不同的國際結構及該國在國際體系中所處的地位,共同決定該國的對外行為。 以此作為論述的基礎檢視日本在戰後的對外關係是否受到當時美蘇結構性對抗所影響,尤其日本在援外政策的執行上是否亦是受到美國的影響。 換言之,即外壓因素在日本對中共的政策開發援助中所扮演的角色如何?
國與國的互動受到國際結構的影響,不容易合作。新現實主義如何解釋現階段中各國間的合作現象呢?而國際社會的本質若依新現實主義者所述為一具有衝突的本質,但論述過程中似乎也不排斥國與國間合作的可能。因此,新現實主義是否有其適當的論點能說明合作之所以可能發生的原因呢?另外新現實主義認為在囚徒困境(Prisoners’ Dilemma)中,囚犯們因為外在環境的限制自然而然會選擇背叛,尤其是加上安全困境的推波助瀾,更使得遊戲者不信任彼此。 因此,藉由合作之建立,增加彼此的信任方是遊戲規則中的大贏家。而如何防止背叛的發生等問題,依新現實主義的思維仍無法提供一完善的解決。
冷戰結束後,是否有其他因素影響日本對中共的援助政策?日本的經濟援助政策是否有所轉變?新自由制度主義的架構是否能對此轉變作一合理的解釋?新自由制度主義認為國家在安全議題的合作受到國際體系影響的層面較大,在經濟議題的合作則是受到國內政治層面影響的程度較大。此是否可以解釋中日雙方儘管在安全議題雙方有所衝突,但郤在經濟議題方面多所合作的原因。新自由制度主義提及的國際建制可以減少,甚至避免背叛的發生。 而中日雙方是否藉由援助而建立在經濟議題方面合作的機制。本論文希望藉由新現實主義及新自由制度主義的架構說明日本在1979年後,對中共的政府開發援助計劃的變與不變。
第三章則是論述日本與中共間正式開始援助關係的時空背景因素,並且檢視新現實主義的論點是否能夠說明雙方間援助關係。尤其是天安門事件發生後,日本政府的處理方式是否透露著雙方間經濟合作前景的不樂觀?亦或是雙方援助關係不受到天安門事件而能持續維繫?
第四章則是論述冷戰後,國際環境結構的調整及日本國內因素是否影響日本對外援助理念的轉換?而以1992ODA援助四大綱作為討論的基礎。並且說明中共核武試驗違背日本ODA援助理念後,日本政府的相關作法為何?日本國內對中ODA是否應該持續已出現不同的意見,是否會影響中日雙方的援助關係?而未來雙方間的ODA援助關係是否應有所調整或轉型?
第五章為結論,將本論文中所探討的問題作綜合整理,以新現實理論與新自由制度主義的論點說明1979年中日開始ODA援助關係後的演變,並且試圖預測未來兩國間ODA援助關係可能的走向。
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Perspectivas e alternativas para a economia de Cabo VerdeMendes, Domingos Veiga January 2010 (has links)
Cabo Verde tem registrado um crescimento considerável em nível da subregião Oeste africana, apesar dos enormes desafios que o país apresenta, tais como escassez de água potável, de energia, de saneamento básico, deficiente infraestrutura, limitados recursos naturais, materiais e humanos. Este trabalho analisa as perspectivas e as alternativas para a economia de Cabo Verde, tendo em conta esses enormes desafios. Para este propósito, o trabalho inicia com a problemática do (sub)desenvolvimento, onde além de uma discussão teórica do assunto, se aborda a questão dos pequenos estados insulares da qual Cabo Verde faz parte e as oportunidades de desenvolvimento que ainda restam aos subdesenvolvidos. Em seguida, apresenta-se um histórico da economia de Cabo Verde, com destaque para os vários momentos verificados desde o período antes da independência até os dias de hoje. Depois se discutem alguns aspetos considerados relevantes da economia Cabo-verdiana, como as contas nacionais, a estrutura do emprego e de desemprego, a caracterização de alguns setores de atividade econômica e, também, faz-se uma análise do desempenho da economia. Por fim, no capítulo 5 discute-se a importância das relações internacionais do país, avaliam-se os desafios que o país enfrenta, as perspectivas de desenvolvimento face a esses desafios, e as alternativas de desenvolvimento, tendo por base o turismo, a ajuda pública ao desenvolvimento (APD), o investimento direto externo (IDE) e as remessas dos emigrantes (RE). Os resultados obtidos neste estudo sugerem que o país, apesar de melhoras significativas em diversas áreas de desenvolvimento, fato comprovado pela recente elevação a País de Rendimento Médio (PRM), o país apresenta ainda enormes desequilíbrios e distorções no seu processo de desenvolvimento. Evidencia-se neste trabalho que, apesar dos constantes desafios e constrangimentos que o país enfrenta, e apesar das alternativas de desenvolvimento se basearem nos fatores externos que não estão sob total controle do país, as perspectivas de desenvolvimento são bastante favoráveis. / Cape Verde has experienced considerable growth in the sub-region of West Africa which is a part, despite the enormous challenges the country presents, such as scarcity of water, energy, sanitation, lack of infrastructure, lack of natural resources, limited human and material resources. This paper analyzes the prospects and the alternatives for the economy of Cape Verde, given these enormous challenges. For this purpose, this work begins with the problem of the (under) development, where in addition to a theoretical discussion of the subject, addressing the issue of small island states which Cape Verde made part and the development opportunities that remain for developing countries. Then comes a history of Cape Verde's economy by addressing various events occurred since the period before independence until today. After that, it is considered some relevant aspects of the Cape Verde economy, such as national accounts, the structure of employment and unemployment, the characterization of certain sectors of economic activity, and also an analysis of economic performance. Finally, in Chapter 5 discusses the importance of the international relations of the country, to assess the challenges facing the country, prospects for development with these challenges, and the alternatives of development, based on tourism, Help official development assistance (ODA), foreign direct investment (FDI) and remittances (RE). The results of this work suggest that the country, despite significant improvements in several areas of the development, proven by the recent graduate to Middle Income Country (MIC), the country still has huge imbalances and distortions in its development process. Evidence in this work, despite the continuing challenges and constraints facing the country, despite the development alternatives are based on the external factors that are not under total control of the country, the development prospects are quite favorable.
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足跡在非洲: 中國大陸和韓國對非洲的援助政策 / Footprints in Africa: a comparative study of China and South Korea's foreign aid policy in Africa申峻浩, Shin, Jun Ho Unknown Date (has links)
This thesis, with special emphasis on African recipient countries, aims to compare and clarify the foreign aid practices adopted by China and South Korea. While South Korea is mostly portrayed as an emerging donor country intending to tie economic relations to recipients, China draws a very diverse audience with reactions to its aid policy ranging from strong suspicion to sincere curiosity.
In this thesis, we examine relationships between economic indicators such as population, Gross Domestic Product (GDP), GDP per capita, trade, Foreign Direct Investment (FDI), energy production of African recipient countries and the foreign aid policies of these two donors. Through the statistical research method of panel data analysis, we found that the Chinese government has a tendency to provide its aid to more populous African countries, while the often hypothesized China’s resource-securing aid intention is not confirmed. In the case of South Korea, Seoul has a more risk-avert attitude in its Official Development Assistance (ODA) by providing these funds to higher income-level recipients.
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Do migrant remittances matter? Nature, determinants and impacts of remittances to PakistanAhmed, Junaid 15 June 2015 (has links)
Diese Arbeit ist eine Sammlung von Studien, welche sowohl die makro-, als auch die mikroökonomischen Aspekte und Charakteristika von Rücküberweisungen pakistanischer Migranten in ihr Heimatland analysieren, sowie deren ökonomische Auswirkungen auf das Konsumverhalten und die Vermögensbildung der Empfängerhaushalte. Es zeigt sich, dass internationale Überweisungen im Vergleich zu anderen finanziellen Mittelflüssen eine stabile und stabilisierende Quelle für Devisen darstellen. Des Weiteren weisen sie mit Blick auf die heimische Wirtschaft ein antizyklisches Verhalten auf, während ihr Verhalten mit Blick auf die Wirtschaft des Gastlandes als azyklisch beschrieben werden kann.
Die Überweisungsströme werden maßgeblich von ihren Transaktionskosten beeinflusst, so dass Migranten in Zeiten hoher Transaktionskosten Rücküberweisungen ins Heimatland entweder einstellen oder informelle Kanäle zum Überweisen nutzen.
Im Rahmen dieser Studie stellt sich außerdem heraus, dass Rücküberweisungen als hauptsächlich kurzfristige Einnahmequelle betrachtet werden. Aufgrund dessen werden die Zuflüsse oftmals in die Förderung von Humankapital investiert, wobei dieser Effekt stark abhängig vom Einkommensniveau des Empfängeraushalts ist.
Ferner führen internationale Überweisungen zu einem erheblichen Anstieg des Haushaltsvermögens, wohingegen Inlandsübweisungen keine signifikanten Vermögensänderungen mit sich bringen. Überdies ermöglichen internationale Rücküberweisungen den Empfängerhaushalten das Aufstocken vorsorglicher Ersparnisse.
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Perspectivas e alternativas para a economia de Cabo VerdeMendes, Domingos Veiga January 2010 (has links)
Cabo Verde tem registrado um crescimento considerável em nível da subregião Oeste africana, apesar dos enormes desafios que o país apresenta, tais como escassez de água potável, de energia, de saneamento básico, deficiente infraestrutura, limitados recursos naturais, materiais e humanos. Este trabalho analisa as perspectivas e as alternativas para a economia de Cabo Verde, tendo em conta esses enormes desafios. Para este propósito, o trabalho inicia com a problemática do (sub)desenvolvimento, onde além de uma discussão teórica do assunto, se aborda a questão dos pequenos estados insulares da qual Cabo Verde faz parte e as oportunidades de desenvolvimento que ainda restam aos subdesenvolvidos. Em seguida, apresenta-se um histórico da economia de Cabo Verde, com destaque para os vários momentos verificados desde o período antes da independência até os dias de hoje. Depois se discutem alguns aspetos considerados relevantes da economia Cabo-verdiana, como as contas nacionais, a estrutura do emprego e de desemprego, a caracterização de alguns setores de atividade econômica e, também, faz-se uma análise do desempenho da economia. Por fim, no capítulo 5 discute-se a importância das relações internacionais do país, avaliam-se os desafios que o país enfrenta, as perspectivas de desenvolvimento face a esses desafios, e as alternativas de desenvolvimento, tendo por base o turismo, a ajuda pública ao desenvolvimento (APD), o investimento direto externo (IDE) e as remessas dos emigrantes (RE). Os resultados obtidos neste estudo sugerem que o país, apesar de melhoras significativas em diversas áreas de desenvolvimento, fato comprovado pela recente elevação a País de Rendimento Médio (PRM), o país apresenta ainda enormes desequilíbrios e distorções no seu processo de desenvolvimento. Evidencia-se neste trabalho que, apesar dos constantes desafios e constrangimentos que o país enfrenta, e apesar das alternativas de desenvolvimento se basearem nos fatores externos que não estão sob total controle do país, as perspectivas de desenvolvimento são bastante favoráveis. / Cape Verde has experienced considerable growth in the sub-region of West Africa which is a part, despite the enormous challenges the country presents, such as scarcity of water, energy, sanitation, lack of infrastructure, lack of natural resources, limited human and material resources. This paper analyzes the prospects and the alternatives for the economy of Cape Verde, given these enormous challenges. For this purpose, this work begins with the problem of the (under) development, where in addition to a theoretical discussion of the subject, addressing the issue of small island states which Cape Verde made part and the development opportunities that remain for developing countries. Then comes a history of Cape Verde's economy by addressing various events occurred since the period before independence until today. After that, it is considered some relevant aspects of the Cape Verde economy, such as national accounts, the structure of employment and unemployment, the characterization of certain sectors of economic activity, and also an analysis of economic performance. Finally, in Chapter 5 discusses the importance of the international relations of the country, to assess the challenges facing the country, prospects for development with these challenges, and the alternatives of development, based on tourism, Help official development assistance (ODA), foreign direct investment (FDI) and remittances (RE). The results of this work suggest that the country, despite significant improvements in several areas of the development, proven by the recent graduate to Middle Income Country (MIC), the country still has huge imbalances and distortions in its development process. Evidence in this work, despite the continuing challenges and constraints facing the country, despite the development alternatives are based on the external factors that are not under total control of the country, the development prospects are quite favorable.
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Perspectivas e alternativas para a economia de Cabo VerdeMendes, Domingos Veiga January 2010 (has links)
Cabo Verde tem registrado um crescimento considerável em nível da subregião Oeste africana, apesar dos enormes desafios que o país apresenta, tais como escassez de água potável, de energia, de saneamento básico, deficiente infraestrutura, limitados recursos naturais, materiais e humanos. Este trabalho analisa as perspectivas e as alternativas para a economia de Cabo Verde, tendo em conta esses enormes desafios. Para este propósito, o trabalho inicia com a problemática do (sub)desenvolvimento, onde além de uma discussão teórica do assunto, se aborda a questão dos pequenos estados insulares da qual Cabo Verde faz parte e as oportunidades de desenvolvimento que ainda restam aos subdesenvolvidos. Em seguida, apresenta-se um histórico da economia de Cabo Verde, com destaque para os vários momentos verificados desde o período antes da independência até os dias de hoje. Depois se discutem alguns aspetos considerados relevantes da economia Cabo-verdiana, como as contas nacionais, a estrutura do emprego e de desemprego, a caracterização de alguns setores de atividade econômica e, também, faz-se uma análise do desempenho da economia. Por fim, no capítulo 5 discute-se a importância das relações internacionais do país, avaliam-se os desafios que o país enfrenta, as perspectivas de desenvolvimento face a esses desafios, e as alternativas de desenvolvimento, tendo por base o turismo, a ajuda pública ao desenvolvimento (APD), o investimento direto externo (IDE) e as remessas dos emigrantes (RE). Os resultados obtidos neste estudo sugerem que o país, apesar de melhoras significativas em diversas áreas de desenvolvimento, fato comprovado pela recente elevação a País de Rendimento Médio (PRM), o país apresenta ainda enormes desequilíbrios e distorções no seu processo de desenvolvimento. Evidencia-se neste trabalho que, apesar dos constantes desafios e constrangimentos que o país enfrenta, e apesar das alternativas de desenvolvimento se basearem nos fatores externos que não estão sob total controle do país, as perspectivas de desenvolvimento são bastante favoráveis. / Cape Verde has experienced considerable growth in the sub-region of West Africa which is a part, despite the enormous challenges the country presents, such as scarcity of water, energy, sanitation, lack of infrastructure, lack of natural resources, limited human and material resources. This paper analyzes the prospects and the alternatives for the economy of Cape Verde, given these enormous challenges. For this purpose, this work begins with the problem of the (under) development, where in addition to a theoretical discussion of the subject, addressing the issue of small island states which Cape Verde made part and the development opportunities that remain for developing countries. Then comes a history of Cape Verde's economy by addressing various events occurred since the period before independence until today. After that, it is considered some relevant aspects of the Cape Verde economy, such as national accounts, the structure of employment and unemployment, the characterization of certain sectors of economic activity, and also an analysis of economic performance. Finally, in Chapter 5 discusses the importance of the international relations of the country, to assess the challenges facing the country, prospects for development with these challenges, and the alternatives of development, based on tourism, Help official development assistance (ODA), foreign direct investment (FDI) and remittances (RE). The results of this work suggest that the country, despite significant improvements in several areas of the development, proven by the recent graduate to Middle Income Country (MIC), the country still has huge imbalances and distortions in its development process. Evidence in this work, despite the continuing challenges and constraints facing the country, despite the development alternatives are based on the external factors that are not under total control of the country, the development prospects are quite favorable.
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The impact of foreign aid on the South African economy (1980-2008Amusa, Rasheedat Gbeminiyi Omotola 26 September 2012 (has links)
M.Com (Economics) / The role of foreign aid in promoting economic growth and improving welfare has been the subject of much debate among development specialists, researchers, aid donors as well as recipients in general. Two very strong views have emerged in the literature; proponents of aid posit that foreign aid contributes to higher welfare levels and economic growth while also improving the socio economic conditions of the poor in the receiving countries. Detractors of the idea that foreign aid promotes growth have argued that aid is not the solution to deep rooted economic problems of recipient countries. According to the latter, aid does not breed an environment that allows nations to themselves develop local strategies to improve growth. The country selected for this study, South Africa, poses an interesting case study given the fact that while the country is not aid- dependent, it still receives a significant amount of official development assistance (ODA). In spite of the above fact and the perceived benefits of foreign aid for growth and development, there are few empirical studies that have investigated the nature of the relationship between foreign aid and economic growth in South Africa. The study found that while foreign aid has positively affected growth in South Africa, the impact is insignificant. Although such aids has ensured a good macroeconomic environment which have been growth- enhancing for the country.
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The Impact of Aid on Human Development Indices in Sub-Saharan AfricaTsokodayi, Jade Takudzwa 02 March 2021 (has links)
This study investigates the relationship between official development assistance (ODA) and human development indicators (HDIs) in 49 sub-Saharan African countries over the period of 1995 to 2017 using 3-stage least squares (3SLS). The four key sub-classes of HDIs considered for this research include education, health, government and civic society, as well as environmental indicators. Of all these HDIs, the results of the analysis show that health aid is the most effective form of aid, significantly reducing the incidence of HIV, the infant mortality rate and the maternal mortality rate, as well as leading to improved life expectancy. Education aid has a significant effect on the progression to secondary school followed by adult literacy rates. Government and civil society aid significantly affects the ability of girls to access education at primary, secondary and tertiary levels while environmental aid is found to increase the carbon efficiency of production. Hence, this study demonstrates that aid is most effective on the health, education and environmental human development indicators.
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從戰略援助角度分析日越關係與ODA政策 / Japan's ODA Policy toward Vietnam and Japan-Vietnam Relationship: From the Perspective of Strategic Aid周芷羽 Unknown Date (has links)
本文主要從戰略援助分析角度論述日越關係與日本對越南實施之政府開發援助(ODA)政策的動機、利弊、具體案例與未來展望;並以日本政府官方文件、國會議事紀錄等檢討日本對越南之ODA政策的評價,試圖分析日本援助越南的意義。
本文首先論述日本的國家利益與戰略援助的關係,以及如何透過戰略援助達成其國家利益;其次,從日本隊東南亞國家的ODA政策的歷史脈絡中,深入研究日本與越南的關係,也就是本文主要研究動機:日本為何選擇越南為ODA政策實施對象?如何援助?這些援助的項目是否符合日本ODA大綱原則以及國別援助方針中所提到的目標?最後從戰略援助角度分析日本對越南ODA政策有無達成強化雙邊關係、維持區域安全等政治性意圖與效果?本文試圖釐清發展脈絡,做出至今為止發展的成果結論,並展望未來的發展。
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