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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.
11

Performance of paste fill fences at Red Lake Mine

Hughes, Paul B. 05 1900 (has links)
Advancements in technology in mining have allowed previously unfeasible ore bodies to be developed. Paste backfill is one technological advancement that has allowed for the development of high-grade, low tonne production when employing the cut and fill mining method. Goldcorp Inc.'s Red Lake Mine currently utilizes this method and is the site for the study of this thesis. Paste backfill (paste) is defined as a mine backfill material that consists of eighty-five percent solids by weight and does not bleed water when placed often consisting of between two and fifteen percent Portland cement by weight. A paste barricade or paste fill fence is a constructed barricade whose purpose is to retain backfill within a mined out stope. The construction of the barricade varies with different operations, for Red Lake Mine the barricade consists of an anchored rebar skeleton covered with an adequate thickness of shotcrete. The majority of the applicable barricade research focuses on hydraulic fill barricades in open stope mining. The barricade pressures in these instances are much larger than those experienced in paste backfill barricades. As such, the current paste loading theory is based on material with a different loading mechanism. Although some research is currently underway, the majority of the barricade research is based on brick barricades and not the shotcrete, rebar skeleton as used at Red Lake. Catastrophic failures of barricades can occur without an understanding of the loading mechanisms. Based on the catastrophic risk, this thesis provides an investigation into the behaviour of the paste backfill and paste barricades at Red Lake Mine in order to provide a safe, cost effective design of paste barricades. This thesis develops an understanding of paste loading mechanisms and barricade capacity derived from a field study of nine instrumented fill fences at Red Lake Mine. Eight of thefences were instrumented to monitor the reaction strain in the fence and the applied pressures during standard production paste pours, the ninth fence was a controlled destructive test that determined the ultimate capacity of the fence. The data for these tests were gathered in real time and was subsequently reduced to assist in analysis. Yield Line Theory, Rankine Theory, strain induced stress, stress vs. strain analysis and numerical modeling were used to develop an understanding of the paste loading mechanisms and the capacity of the paste fill barricades. The analysis determined that the paste backfill behaves as a Rankine-like soil in the initial stages of loading with an average coefficient of lateral earth pressure, Ka, of 0.56. The destructive test determined that the yielding stress of a paste barricade is approximately 100 kPa. Further findings from the research determined that the rate of placement of paste does effect the loads applied to the fence and that the largest pressures exerted on the fill fence occur when paste lines were flushed with water at the end of the pour. This thesis provides an understanding of the paste loading and fill fence interaction with respect to failure. Based on this research the Red Lake Mine should be able to increase production without increasing risk to mine personnel by quantifying the overall loading and strengths of the fill barricade. / Applied Science, Faculty of / Mining Engineering, Keevil Institute of / Graduate
12

Análise experimental do efeito aerodinâmico de dispositivos de asa e ponta de asa em uma aeronave tipo \"Blended Wing Body\" / Experimental analysis of the aerodynamic effect of the wing and wing tip devices on a \"Blended Wing Body\"

Diaz Izquierdo, David Orlando 21 October 2015 (has links)
Este trabalho tem por objetivo analisar o comportamento aerodinâmico de dispositivos de ponta de asa e Fences acoplados em uma aeronave Blended Wing Body (BWB) através de testes em túnel de vento. A BWB é um projeto de aeronave alternativo que faz parte do conceito de aeronaves sustentáveis. O Laboratório de Aeronaves da Escola de Engenharia de São Carlos, Universidade de São Paulo, vem realizando uma série de pesquisas sobre este assunto. Em trabalhos anteriores com o modelo BWB foram observados a presença tanto de um escoamento transversal na parte externa quanto um forte vórtice no meio do modelo. A fim de melhorar o primeiro protótipo o Droop, bem como um arranjo de três Fences foram adicionados no modelo BWB. Além disso, os dispositivos Winglets e C-wing foram considerados neste estudo. Entre o desenvolvimento de aeronaves, vários dispositivos têm sido estudados e implementados em aeronaves convencionais. Estes tem várias vantagens, tais como a melhoria da eficiência aerodinâmica e a redução do arrasto induzido e efeitos positivos no rendimento do avião. Os dispositivos de ponta da asa criam uma força aerodinâmica em que um do seus componentes atua na direção do voo, esta também pode contribuir para a redução da intensidade dos vórtices nas pontas da asa, reduzindo o arrasto induzido. Pesquisas em aeronaves não convencionais mostraram que BWB poderia ter melhores características aerodinâmicas do que uma aeronave convencional. Aindústriaaeronáuticaestáprocurandoareduçãodoscustosoperacionais,bemcomo a adaptação das aeronaves para a restrição legislativa das emissões de gases e poluição sonora. Nas últimas décadas, esta redução não teve uma melhora significativa em termos de valores absolutos para configurações convencionais, isso fez com que novas e mais eficientes configurações têm sido estudadas. A interferência dos diferentes dispositivos no modelo BWB foram analisados em teste em túnel de vento. Os experimentos foram realizados no Laboratório de Aeronaves da Escola de Engenharia de São Carlos, Universidade de São Paulo. Foi utilizado um túnel de vento fechado com uma seção de teste de 1.7x1.3x3 [m]. O ângulo de ataque foi variado desde -4º a 20º e Re = 390.000. Os resultados mostram que os dispositivos nas pontas da asa melhoraram o desempenho da aeronave, bem como a eficiência aerodinâmica. Com relação aos Fence este comportamento não foi observado. Entre tanto, em ângulos elevados a eficiência foi aumentada. Através da técnica de visualização oil flow observou-se que o escoamento sobre a asa foi redirecionado diminuindo o coeficiente de arrasto em ângulos de ataque elevados. / This work aims to analyze the aerodynamic behavior of wingtip devices and Fences coupled on a Blended Wing Body aircraft (BWB) through wind tunnel tests. The BWB is an alternative of airship design which makes up part of the Green aircraft concept. The Aircraft Laboratory of the School of Engineering of São Carlos-University of São Paulo has been carrying out a lot of research into this subject. In previous works with a BWB model, the presence both of a cross flow on the external part and a stronger vortex in the middle of the model have been observed. In order to improve the first prototype a Droop as well as an arrangement of three Fences were added on the BWB model. Furthermore the Winglets, C-wing devices were considered in this study. Among the aircraft development, several devices have been studied and implemented in conventional aircraft. These ones had several advantages such as improving the aerodynamic efficiency and induced drag reduction and getting positive effects on aircraft performance. The wingtip devices create an aerodynamic force in which one of this components acts in the flight direction, also these can contribute to the reduction of the wingtip vortices strength, reducing the induced drag. Researches in non conventional aircraft has shown that BWB could have better aerodynamic characteristics than a conventional aircraft. The aeronautical industry is looking for the reduction of direct operational cost, as well as the adaptation of aircrafts to the demanding legislative restriction of gas emissions and noise pollution. In the last few decades this reductions has not had a significant improvement in terms of absolute values for conventional configurations, this has meant that new and more efficient configurations have been studied. The interference of the different devices on the BWB model were analyzed in wind tunnel test. The experiments were carried out in the Aircraft Laboratory of the School of Engineering of São Carlos-University of São Paulo. A closed wind tunel with a section work of 1.7x1.3x3 [m] was used. The angle of attack was varied from -4º to 20º and Re = 390.000. The results shows that the wing tip devices improved the aircraft performance as well as the aerodynamic efficiency. Regarding the Fences this behavior was not observed. However, at higher angles the efficiency was increased. Through oil flow visualization it was observed that the flow over the wing was redirected decreasing the drag coeficient at higher attack angles.
13

Análise experimental do efeito aerodinâmico de dispositivos de asa e ponta de asa em uma aeronave tipo \"Blended Wing Body\" / Experimental analysis of the aerodynamic effect of the wing and wing tip devices on a \"Blended Wing Body\"

David Orlando Diaz Izquierdo 21 October 2015 (has links)
Este trabalho tem por objetivo analisar o comportamento aerodinâmico de dispositivos de ponta de asa e Fences acoplados em uma aeronave Blended Wing Body (BWB) através de testes em túnel de vento. A BWB é um projeto de aeronave alternativo que faz parte do conceito de aeronaves sustentáveis. O Laboratório de Aeronaves da Escola de Engenharia de São Carlos, Universidade de São Paulo, vem realizando uma série de pesquisas sobre este assunto. Em trabalhos anteriores com o modelo BWB foram observados a presença tanto de um escoamento transversal na parte externa quanto um forte vórtice no meio do modelo. A fim de melhorar o primeiro protótipo o Droop, bem como um arranjo de três Fences foram adicionados no modelo BWB. Além disso, os dispositivos Winglets e C-wing foram considerados neste estudo. Entre o desenvolvimento de aeronaves, vários dispositivos têm sido estudados e implementados em aeronaves convencionais. Estes tem várias vantagens, tais como a melhoria da eficiência aerodinâmica e a redução do arrasto induzido e efeitos positivos no rendimento do avião. Os dispositivos de ponta da asa criam uma força aerodinâmica em que um do seus componentes atua na direção do voo, esta também pode contribuir para a redução da intensidade dos vórtices nas pontas da asa, reduzindo o arrasto induzido. Pesquisas em aeronaves não convencionais mostraram que BWB poderia ter melhores características aerodinâmicas do que uma aeronave convencional. Aindústriaaeronáuticaestáprocurandoareduçãodoscustosoperacionais,bemcomo a adaptação das aeronaves para a restrição legislativa das emissões de gases e poluição sonora. Nas últimas décadas, esta redução não teve uma melhora significativa em termos de valores absolutos para configurações convencionais, isso fez com que novas e mais eficientes configurações têm sido estudadas. A interferência dos diferentes dispositivos no modelo BWB foram analisados em teste em túnel de vento. Os experimentos foram realizados no Laboratório de Aeronaves da Escola de Engenharia de São Carlos, Universidade de São Paulo. Foi utilizado um túnel de vento fechado com uma seção de teste de 1.7x1.3x3 [m]. O ângulo de ataque foi variado desde -4º a 20º e Re = 390.000. Os resultados mostram que os dispositivos nas pontas da asa melhoraram o desempenho da aeronave, bem como a eficiência aerodinâmica. Com relação aos Fence este comportamento não foi observado. Entre tanto, em ângulos elevados a eficiência foi aumentada. Através da técnica de visualização oil flow observou-se que o escoamento sobre a asa foi redirecionado diminuindo o coeficiente de arrasto em ângulos de ataque elevados. / This work aims to analyze the aerodynamic behavior of wingtip devices and Fences coupled on a Blended Wing Body aircraft (BWB) through wind tunnel tests. The BWB is an alternative of airship design which makes up part of the Green aircraft concept. The Aircraft Laboratory of the School of Engineering of São Carlos-University of São Paulo has been carrying out a lot of research into this subject. In previous works with a BWB model, the presence both of a cross flow on the external part and a stronger vortex in the middle of the model have been observed. In order to improve the first prototype a Droop as well as an arrangement of three Fences were added on the BWB model. Furthermore the Winglets, C-wing devices were considered in this study. Among the aircraft development, several devices have been studied and implemented in conventional aircraft. These ones had several advantages such as improving the aerodynamic efficiency and induced drag reduction and getting positive effects on aircraft performance. The wingtip devices create an aerodynamic force in which one of this components acts in the flight direction, also these can contribute to the reduction of the wingtip vortices strength, reducing the induced drag. Researches in non conventional aircraft has shown that BWB could have better aerodynamic characteristics than a conventional aircraft. The aeronautical industry is looking for the reduction of direct operational cost, as well as the adaptation of aircrafts to the demanding legislative restriction of gas emissions and noise pollution. In the last few decades this reductions has not had a significant improvement in terms of absolute values for conventional configurations, this has meant that new and more efficient configurations have been studied. The interference of the different devices on the BWB model were analyzed in wind tunnel test. The experiments were carried out in the Aircraft Laboratory of the School of Engineering of São Carlos-University of São Paulo. A closed wind tunel with a section work of 1.7x1.3x3 [m] was used. The angle of attack was varied from -4º to 20º and Re = 390.000. The results shows that the wing tip devices improved the aircraft performance as well as the aerodynamic efficiency. Regarding the Fences this behavior was not observed. However, at higher angles the efficiency was increased. Through oil flow visualization it was observed that the flow over the wing was redirected decreasing the drag coeficient at higher attack angles.
14

Electric Fence to PC Wireless Radio Frequency Communications Interface

Gomez Poo, David Fernando January 2006 (has links)
Electric fencing is commonly used on New Zealand's farms. Modern technology is used in farm management systems to solve old farming problems in a more efficient and simple way. Engineers have researched the use of the electric fence as a communication medium and new technologies based on transmission line theory are used at present to monitor and troubleshoot problems occurring in electric fences. The next stage of the development is to use wireless devices to accomplish those same tasks from remote locations. This project aims to develop a prototype that provides a wireless link between an electric fence and a personal computer in a remote location. This prototype is expected to prove concepts that lead to the future design of useful, marketable products. The project was supported by Gallagher Electronics and is implemented using their existing products where possible.
15

Creosoted Tamarisk Fence Posts and Adaptability of Tamarisk as a Fine Cabinet Wood

Smith, G. E. P. 15 June 1941 (has links)
This item was digitized as part of the Million Books Project led by Carnegie Mellon University and supported by grants from the National Science Foundation (NSF). Cornell University coordinated the participation of land-grant and agricultural libraries in providing historical agricultural information for the digitization project; the University of Arizona Libraries, the College of Agriculture and Life Sciences, and the Office of Arid Lands Studies collaborated in the selection and provision of material for the digitization project.
16

Uso de cercas-vivas por aves em uma paisagem fragmentada de mata atlântica semidecídua /

Gabriel, Vagner de Araújo. January 2005 (has links)
Orientador: Marco Aurélio Pizo Ferreira / Banca: Marcos Rodrigues / Banca: Reginaldo José Donatelli / Resumo: Esta pesquisa investigou o uso de cercas-vivas por aves em uma paisagem fragmentada de Mata Atlântica semidecídua em Itatiba, São Paulo. Objetivou-se (1) determinar quais espécies de aves utilizam as cercas-vivas, (2) que atividades aí realizam, (3) verificar a disponibilidade de frutos e artrópodes nas cercas-vivas, (4) se a presença das aves nas cercas-vivas está relacionada à disponibilidade desses recursos alimentares e (5) caracterizar a estrutura da vegetação das cercas-vivas e compará-las aos fragmentos estudados. Foram estudados cinco fragmentos e três cercas-vivas, que conectam tais fragmentos. Nove redes de neblina foram instaladas nas cercas-vivas e 15 nos fragmentos para a captura e anilhamento de aves. Pela recaptura das aves foi inferida a função das cercas-vivas como corredor. Taxas de captura nas cercas-vivas e fragmentos foram comparadas. Para isso foram consideradas, separadamente, guildas de aves frugívoras, insetívoras, granívoras-frugívoras, granívoras-insetívoras e nectarívorasinsetívoras. Quanto às taxas de captura, excetuando-se a taxa de captura de aves insetívoras, houve diferença significativa entre cercas-vivas e fragmentos, sendo sempre maiores nas cercas-vivas. Não houve diferença na oferta de frutos e artrópodes entre cercas-vivas e fragmentos. As taxas de captura de aves frugívoras e insetívoras não estiveram relacionadas à disponibilidade de frutos e artrópodes. Cercas-vivas e fragmentos pouco diferiram quanto à estrutura da vegetação. Concluiu-se que a presença de cercas-vivas pode amenizar os efeitos do isolamento a que estão sujeitas muitas aves tropicais devido à fragmentação de seu habitat / Abstract: This study investigated the use of live fences by birds in a fragmented Atlantic forest landscape in Itatiba, SE Brazil. The purpose of it was (1) identify what bird species use the live fences, (2) record what they do in the live fences, (3) investigate the availability of food resources (fruit and arthropod) in live fences, (4) investigate if the food availability influences the use of live fences by birds and (5) characterize the vegetation structure of live fences and forest fragments. Five forest fragments and three live fences that connect such fragments were studied. Nine mist-nets were installed in live fences and 15 in forest fragments to capture and band birds. For this, captured birds were classified into the following foraging guilds: frugivores, insectivores, granivores-frugivores, granivoresinsectivores and nectarivores-insectivores. Except for insectivorous birds, significant differences in capture rates between live fences and forest fragments were detected. Capture rates in live fences were always greater than in fragments. There was no difference in the availability of food resources between live fences and fragments. The capture rates of frugivorous and insectivorous birds were not related to the availability of fruits and arthropods. The vegetation structure at live fences and forest fragments differed little from each other. I concluded that live fences can serve as movement corridors for birds at the study site, thus helping to reduce the usually deleterious effects of isolation caused forest fragmentation / Mestre
17

橋梁用防護柵の性能照査型統合設計システム

伊藤, 義人, ITOH, Yoshito, 鈴木, 達, SUZUKI, Toru 04 1900 (has links)
No description available.
18

Not Quite Right

2015 September 1900 (has links)
My current area of exploration questions how objects and materials can come together to create fences or barriers. I am attempting to address ideas of boundaries, divisions, and borders, and how areas and spaces are defined. I am interested in how we build them around ourselves, physically and emotionally, as a method of delineation and defence. Through considerations of boundaries the work expands to explore notions of the everyday, materiality and process.
19

Development of an FRP Reinforced Hardwood Glulam Guardrail

Botting, Joshua Keith January 2003 (has links) (PDF)
No description available.
20

Uso de cercas-vivas por aves em uma paisagem fragmentada de mata atlântica semidecídua

Gabriel, Vagner de Araújo [UNESP] 18 April 2005 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:30:15Z (GMT). No. of bitstreams: 0 Previous issue date: 2005-04-18Bitstream added on 2014-06-13T19:39:36Z : No. of bitstreams: 1 gabriel_va_me_rcla.pdf: 781557 bytes, checksum: 14c35f8bd36a58f818bd1e877323dd1d (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Esta pesquisa investigou o uso de cercas-vivas por aves em uma paisagem fragmentada de Mata Atlântica semidecídua em Itatiba, São Paulo. Objetivou-se (1) determinar quais espécies de aves utilizam as cercas-vivas, (2) que atividades aí realizam, (3) verificar a disponibilidade de frutos e artrópodes nas cercas-vivas, (4) se a presença das aves nas cercas-vivas está relacionada à disponibilidade desses recursos alimentares e (5) caracterizar a estrutura da vegetação das cercas-vivas e compará-las aos fragmentos estudados. Foram estudados cinco fragmentos e três cercas-vivas, que conectam tais fragmentos. Nove redes de neblina foram instaladas nas cercas-vivas e 15 nos fragmentos para a captura e anilhamento de aves. Pela recaptura das aves foi inferida a função das cercas-vivas como corredor. Taxas de captura nas cercas-vivas e fragmentos foram comparadas. Para isso foram consideradas, separadamente, guildas de aves frugívoras, insetívoras, granívoras-frugívoras, granívoras-insetívoras e nectarívorasinsetívoras. Quanto às taxas de captura, excetuando-se a taxa de captura de aves insetívoras, houve diferença significativa entre cercas-vivas e fragmentos, sendo sempre maiores nas cercas-vivas. Não houve diferença na oferta de frutos e artrópodes entre cercas-vivas e fragmentos. As taxas de captura de aves frugívoras e insetívoras não estiveram relacionadas à disponibilidade de frutos e artrópodes. Cercas-vivas e fragmentos pouco diferiram quanto à estrutura da vegetação. Concluiu-se que a presença de cercas-vivas pode amenizar os efeitos do isolamento a que estão sujeitas muitas aves tropicais devido à fragmentação de seu habitat. / This study investigated the use of live fences by birds in a fragmented Atlantic forest landscape in Itatiba, SE Brazil. The purpose of it was (1) identify what bird species use the live fences, (2) record what they do in the live fences, (3) investigate the availability of food resources (fruit and arthropod) in live fences, (4) investigate if the food availability influences the use of live fences by birds and (5) characterize the vegetation structure of live fences and forest fragments. Five forest fragments and three live fences that connect such fragments were studied. Nine mist-nets were installed in live fences and 15 in forest fragments to capture and band birds. For this, captured birds were classified into the following foraging guilds: frugivores, insectivores, granivores-frugivores, granivoresinsectivores and nectarivores-insectivores. Except for insectivorous birds, significant differences in capture rates between live fences and forest fragments were detected. Capture rates in live fences were always greater than in fragments. There was no difference in the availability of food resources between live fences and fragments. The capture rates of frugivorous and insectivorous birds were not related to the availability of fruits and arthropods. The vegetation structure at live fences and forest fragments differed little from each other. I concluded that live fences can serve as movement corridors for birds at the study site, thus helping to reduce the usually deleterious effects of isolation caused forest fragmentation.

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