Segui questo link per vedere altri tipi di pubblicazioni sul tema: Low-pressure injection.

Tesi sul tema "Low-pressure injection"

Cita una fonte nei formati APA, MLA, Chicago, Harvard e in molti altri stili

Scegli il tipo di fonte:

Vedi i top-23 saggi (tesi di laurea o di dottorato) per l'attività di ricerca sul tema "Low-pressure injection".

Accanto a ogni fonte nell'elenco di riferimenti c'è un pulsante "Aggiungi alla bibliografia". Premilo e genereremo automaticamente la citazione bibliografica dell'opera scelta nello stile citazionale di cui hai bisogno: APA, MLA, Harvard, Chicago, Vancouver ecc.

Puoi anche scaricare il testo completo della pubblicazione scientifica nel formato .pdf e leggere online l'abstract (il sommario) dell'opera se è presente nei metadati.

Vedi le tesi di molte aree scientifiche e compila una bibliografia corretta.

1

McNaught, PL. "Low pressure fuel injection of a two-stroke cycle spark ignition engine". Thesis, University of Cape Town, 1986. http://hdl.handle.net/11427/23297.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
2

Wright, Glenn C. "Control of Brown Wood Rot in Lemons with Low Pressure Injection 2012". College of Agriculture, University of Arizona (Tucson, AZ), 2015. http://hdl.handle.net/10150/345170.

Testo completo
Abstract (sommario):
8 pp.
We injected AGRA PHOS (Potassium Phosphite) 0-2.4-2, Propaconizole – 0.05%, Propaconizole plus Azoxystrobin – 0.117 and 0.135% respectively, Zn, Mn and Fe 0.105, 0.112, and 0.10% respectively, and Azoxystrobin – 0.137% using a low pressure injection system for the control of Antrodia sinuosa in lemon trees. The Propaconizole + Azoxystrobin treatment, the Azoxystrobin treatment, and the Zn + Mn + Fe treatment led to significantly less fungal lesion growth when applied prior to the introduction of the fungus, as compared to their application after fungal introduction.
Gli stili APA, Harvard, Vancouver, ISO e altri
3

Wright, Glenn C. "Control of Brown Wood Rot in Lemons with Low Pressure Injection 2013-14". College of Agriculture, University of Arizona (Tucson, AZ), 2015. http://hdl.handle.net/10150/578401.

Testo completo
Abstract (sommario):
6 pp.
We injected AGRA PHOS (Potassium Phosphite) 0-2.4-2, Propiconizole – 0.05%, Zn, Mn and Fe 0.105, 0.112, and 0.10% respectively, Zn, Mn and Fe 0.210, 0.220, and 0.200% respectively and Propiconizole – 0.05% + Zn, Mn and Fe 0.105, 0.112, and 0.10% respectively using a low pressure injection system for the control of Antrodia sinuosa in lemon trees. No treatment led to a significant reduction in fungal growth.
Gli stili APA, Harvard, Vancouver, ISO e altri
4

Kowalski, Sebastian. "Rheology based investigation of a polymer-mineral powder mix for low pressure injection moulding". Limoges, 2005. http://aurore.unilim.fr/theses/nxfile/default/80dadd89-fb07-4918-8b88-5fd642b79cac/blobholder:0/2005LIMO0015.pdf.

Testo completo
Abstract (sommario):
La pâte céramique étudiée, mélange de plusieurs polymères immiscibles : paraffine, EVA, cire de carnauba et d'une poudre minérale submicronique est utilisée dans le procédé d'injection. On s'est surtout attaché à corréler les propriétés rhéologiques à 130°C à la physico-chimie du system. Plusieurs paramètres ont été modifiés, - la fraction volumique, la composition du mélange de polymères et la nature de la poudre. On a montré que les molécules d'EVA et de carnauba sont adsorbées sur la surface de ZrO2, dans un rapport volumique de 2/1 et la poudre fait des inclusions dans la paraffine. Pour une fraction volumique >50% vol. , la pâte se comporte comme un solide et montre des propriétés de thixotropie – analysées avec un modèle développé par Piau. Un rhéomètre capillaire a été utilisé pour estimer la viscosité élongationelle, qui est très sensible (contraire à la viscosité de cisaillement), et clairement lié à la quantité d'EVA adsorbé
. The rheological properties of a ceramic paste, comprising several immiscible polymers : paraffin wax, EVA, carnauba wax, mixed with a mineral submicronic powder were investigated at 130°C. It is a prerequisite to master a forming process such as injection moulding and this was one of the pursued objectives. The other one was to relate these properties to the physico-chemical composition. Several parameters were modified i. E. - the vol. Solid fraction, the polymer blend composition and the nature of the powder. It was proved that EVA and carnauba molecules adsorb on ZrO2 surface, in a volume ratio 2/1 and the powder makes inclusions in the liquid paraffin. For a vol. Fraction >50%, a solid-liquid transition occurs - paste shows a thixotropic behaviour-analyzed with a model developed by Piau. A capillary rheometer was used to estimate the extensional viscosity, which is very sensitive (contrary to shear viscosity), and clearly related to the amount of adsorbed EVA
Gli stili APA, Harvard, Vancouver, ISO e altri
5

McCluney, Peter. "Development of a small natural gas fuelled two stroke cycle engine using low pressure injection". Thesis, Queen's University Belfast, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.241433.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
6

Ahmed, Abdelallah. "Investigation of High Pressure Combustion and Emissions Characteristics of a Lean Direct Injection Combustor Concept". University of Cincinnati / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1471345597.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
7

Zhang, Kaiyi. "CO2 Minimum Miscibility Pressure and Recovery Mechanisms in Heterogeneous Low Permeability Reservoirs". Thesis, Virginia Tech, 2019. http://hdl.handle.net/10919/93728.

Testo completo
Abstract (sommario):
Benefited from the efficiency of hydraulic fracturing and horizon drilling, the production of unconventional oil and gas resources, such as shale gas and tight oil, has grown quickly in 21th century and contributed to the North America oil and gas production. Although the new enhancing oil recover (EOR) technologies and strong demand spike the production of unconventional resources, there are still unknowns in recovery mechanisms and phase behavior in tight rock reservoirs. In such environment, the phase behavior is altered by high capillary pressure owing to the nanoscale pore throats of shale rocks and it may also influence minimum miscibility pressure (MMP), which is an important parameter controlling gas floods for CO2 injection EOR. To investigate this influence, flash calculation is modified with considering capillary pressure and this work implements three different method to calculate MMP: method of characteristics (MOC); multiple mixing cell (MMC); and slim-tube simulation. The results show that CO2 minimum miscibility pressure in nanopore size reservoirs are affected by gas-oil capillary pressure owing to the alternation of key tie lines in displacement. The values of CO2-MMP from three different methods match well. Moreover, in tight rock reservoirs, the heterogeneous pore size distribution, such as the ones seen in fractured reservoirs, may affect the recovery mechanisms and MMP. This work also investigates the effect of pore size heterogeneity on multicomponent multiphase hydrocarbon fluid composition distribution and its subsequent influence on mass transfer through shale nanopores. According to the simulation results, compositional gradient forms in heterogeneous nanopores of tight reservoirs because oil and gas phase compositions depend on the pore size. Considering that permeability is small in tight rocks and shales, we expect that mass transfer within heterogeneous pore size porous media to be diffusion-dominated. Our results imply that there can be a selective matrix-fracture component mass transfer during both primary production and gas injection secondary recovery in fractured shale rocks. Therefore, molecular diffusion should not be neglected from mass transfer equations for simulations of gas injection EOR or primary recovery of heterogeneous shale reservoirs with pore size distribution.
Master of Science
The new technologies to recover unconventional resources in oil and gas industry, such as fracturing and horizontal drilling, boosted the production of shale gas and tight oil in 21st century and contributed to the North America oil and gas production. Although the new technologies and strong demand spiked the production of tight oil resources, there are still unknowns of oil and gas flow mechanisms in tight rock reservoirs. As we know, the oil and gas resources are stored in the pores of reservoir formation rock. During production process, the oil and gas are pushed into production wells by formation pressure. However, the pore radius of shale rock is extremely small (around nanometers), which reduces the flow rate of oil and gas and raises capillary pressure in pores. The high capillary pressure will alter the oil and gas phase behavior and it may influence the value of minimum miscibility pressure (MMP), which is an important design parameter for CO2 injection (an important technology to raise production). To investigate this influence, we changed classical model with considering capillary pressure and this modified model is implemented in different methods to calculate MMP. The results show that CO2 -MMP in shale reservoirs are affected by capillary pressure and the results from different methods match well. Moreover, in tight rock reservoirs, the heterogeneous pore size distribution, such as fractures in reservoirs, may affect the flow of oil and gas and MMP value. So, this work also investigates the effect of pore size heterogeneity on oil and gas flow mechanisms. According to the simulation results, compositional gradient forms in heterogeneous nanopores of tight reservoirs and this gradient will cause diffusion which will dominate the other fluid flow mechanisms. Therefore, we always need to consider molecular diffusion in the simulation model for shale reservoirs.
Gli stili APA, Harvard, Vancouver, ISO e altri
8

Günter, Marcel [Verfasser]. "Investigation of Turbulent Intra-Fluid Heat Transfer in a Low-Pressure Turbine with Hot-Streak Injection / Marcel Günter". München : Verlag Dr. Hut, 2019. http://d-nb.info/120075476X/34.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
9

Mercan, Bayram. "Experimental Investigation Of The Effects Of Waveform Tip Injection On The Characteristics Of Tip Leakage Vortex In A Lpt Cascade". Master's thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12614111/index.pdf.

Testo completo
Abstract (sommario):
This study presents the results of an experimental study that investigates the effects of uniform/waveform tip injection along the camberline on the total pressure loss characteristics downstream of a row of Low Pressure Turbine (LPT) blades. The experiments are performed in a low speed cascade facility. This injection technique involves spanwise jets at the tip that are issued from a series of holes along the camber line normal to the freestream flow direction. The injection mass flow rate from each hole is individually controlled using computer driven solenoid valves and therefore the flow injection geometrical pattern at the tip can be adjusted to any desired waveform shape, and can be uniform as well as waveform along the camber. Measurements involve Kiel probe traverses for different injection scenarios 0.5 axial chords downstream of the blades. Results show that, instead of performing uniform mass injection along the camberline, by selecting an appropriate waveform injection pattern one can reduce the total loss levels of the blade, including the tip leakage loss as well as the wake losses.
Gli stili APA, Harvard, Vancouver, ISO e altri
10

Kordiovský, Jan. "Optimalizace průtoku vstřiků od KČ II° do systému SPP". Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2017. http://www.nusl.cz/ntk/nusl-318675.

Testo completo
Abstract (sommario):
The diploma thesis deals with the topic of the optimization calculation of the mass flow of injection from the condensing pumps of the second degree to the condensate of heating steam, flowing from the system of separation and reheating, with the main goal to achieve the maximum power of the block of the power plant. There is calculation of the secondary circuit of the nuclear power plant in Dukovany before and after the optimization. In the next part, there is calculated growth of electric power of the block, results are drawn in diagrams and technical solution is designed.
Gli stili APA, Harvard, Vancouver, ISO e altri
11

Andreola, Raquel. "Conformação de molas cerâmicas por moldagem por injeção em baixa pressão". reponame:Repositório Institucional da UCS, 2007. https://repositorio.ucs.br/handle/11338/226.

Testo completo
Abstract (sommario):
Neste trabalho foi estudado o processo de moldagem por injeção em baixa pressão (LPIM do inglês: low-pressure injection molding) de pós cerâmicos submicrométricos para a produção de molas cerâmicas. O trabalho compreende a confecção de moldes e pequenas injetoras de laboratório, extração dos ligantes orgânicos utilizados durante a moldagem, a sinterização das peças e alguns ensaios preliminares para avaliar as propriedades mecânicas de molas cerâmicas. A LPIM apresenta muitas vantagens na produção de peças cerâmicas complexas, quando comparada à moldagem por injeção tradicional. Entretanto LPIM apresenta alguns problemas na remoção da mistura de ligantes que são maiores quando se confecciona peças cerâmicas preparadas com pós submicrométricos. Mas, por outro lado, a utilização destes pós permite a obtenção de corpos sinterizados com alta densidade e excelentes propriedades mecânicas. Os pós cerâmicos utilizados foram a alumina (Al2O3) e a zircônia (ZrO2), e o ligante principal utilizado foi a parafina. Moldes tubulares e moldes usinados multipartidos foram desenvolvidos para moldagem por injeção de molas de alumina e uma pequena injetora foi construída para injetar peças de zircônia. Os moldes tubulares mostraram-se pouco adequados. Por outro lado, a utilização do molde de latão multipartido, revestido com PTFE (politetrafluoretileno), melhorou o processo de fabricação de molas cerâmicas, possibilitando a confecção de quantidades maiores e com boa reprodutibilidade. No processo de sinterização das molas cerâmicas as distorções foram evitadas utilizando cilindros cerâmicos como suporte das molas. As molas de alumina e zircônia tiveram suas densidades e durezas medidas e estão de acordo com a literatura. Finalmente, foram feitos alguns ensaios preliminares de compressão com molas cerâmicas de alumina e zircônia para avaliar sua constante de mola e a carga máxima suportada antes da quebra.
Submitted by Marcelo Teixeira (mvteixeira@ucs.br) on 2014-05-15T16:08:53Z No. of bitstreams: 1 Dissertacao Raquel Andreola.pdf: 15781483 bytes, checksum: 33fd01d3cfc733b522788fea2e290b5a (MD5)
Made available in DSpace on 2014-05-15T16:08:53Z (GMT). No. of bitstreams: 1 Dissertacao Raquel Andreola.pdf: 15781483 bytes, checksum: 33fd01d3cfc733b522788fea2e290b5a (MD5)
In this work the low-pressure injection molding (LPIM) of submicrometer-sized ceramic powders was studied aiming to produce ceramic springs. The work comprised the production of molds and laboratory equipment for injection molding, the debinding of the organic vehicle used in the molding, the sintering of ceramic parts, and some preliminary experiments to evaluate the mechanical properties of the ceramics springs. The LPIM presents many advantages for complex ceramic parts production, in comparison with traditional high-pressure injection molding. However, LPIM has some difficulties associated to the debinding step, that are even greater for ceramic parts made with submicrometer-sized powders. But, on the other hand, the use of submicrometer-sized powders allows the production of sintered bodies with high density and better mechanical properties. The submicrometer-sized ceramic powders used in this work were alumina (Al2O3) and zirconia (ZrO2), and the main binder was the paraffin. Tubular molds and a multipart machined mold were developed for injection molding of alumina springs, and a little injection machine was build for injection molding of zirconia parts. The tubular molds had a limited performance. On the other hand, the multipart brass mold, coated with PTFE (polytetrafluorethylene), improved the ceramics spring molding process, making it possible to produce ceramic springs in greater quantities with good reproducibility. In the sintering process of the ceramic springs, major distortions of the parts were avoided using ceramic beams to support the springs. The alumina and zirconia ceramic springs had their measured density and hardness in good agreement with literature. Finally, some preliminary compression tests were performed with alumina and zirconia ceramic springs in order to evaluate their spring constant and maximum load before failure.
Gli stili APA, Harvard, Vancouver, ISO e altri
12

Kraehn, Baptiste. "Approche intégrée matériau-procédé appliquée à la conception de doigts souples pour la manipulation dextre". Electronic Thesis or Diss., Strasbourg, 2024. http://www.theses.fr/2024STRAD042.

Testo completo
Abstract (sommario):
Ce travail de thèse propose une approche intégrée pour le développement de doigts pneumatiques en silicone destinés à la manipulation dextre. Basée sur une démarche comparative entre l'expérimentation et la prédiction numérique, l'identification des modèles de comportement du silicone permet de prédire le comportement du doigt pneumatique. La conception de celui-ci est alors guidée par simulation, avec pour objectif de réduire la dépendance du comportement du doigt à l'effet Mullins. La méthode de fabrication retenue, l'injection basse pression, permet la mise en place d'un processus de fabrication robuste par surmoulage des renforts rigides et de la base du doigt. La conception du doigt et de l'outillage est définie de manière à permettre la production de l'assemblage complet en une unique étape d'injection
This thesis proposes an integrated approach to the design of pneumatic silicone fingers for dexterous manipulation. Based on a comparative approach between experimentation and numerical prediction, the identification of silicone behavioral models allows the prediction of pneumatic finger behavior. The design is then guided by simulation with the aim of reducing the finger's dependence on the Mullins effect. The chosen manufacturing method, low-pressure injection molding, allows a robust overmolding process for the rigid reinforcements and the base of the finger. The finger and tooling are designed to enable production of the complete assembly in a single injection step
Gli stili APA, Harvard, Vancouver, ISO e altri
13

Barbieri, Rodrigo Antonio. "Influência da temperatura de sinterização nas propriedades mecânicas de molas de alumina injetadas em baixa pressão". reponame:Repositório Institucional da UCS, 2011. https://repositorio.ucs.br/handle/11338/613.

Testo completo
Abstract (sommario):
Neste trabalho foram produzidas molas cerâmicas através do processo de moldagem por injeção em baixa pressão, utilizando-se como matéria-prima alumina submicrométrica, aditivada com ligantes a base de ceras. Dentro do tanque de uma injetora Pelstman, estes materiais foram homogeneizados e resultaram em uma suspensão de baixa viscosidade. Entre os objetivos deste trabalho estão a produção de molas cerâmicas helicoidais com perfil circular, a extração dos ligantes orgânicos utilizados durante a moldagem, a pré-sinterização das molas a 1000°C, o acabamento e a sinterização das molas em diferentes temperaturas e a medida de algumas de suas propriedades. A mudança na temperatura de sinterização é uma maneira simples de alterar as propriedades das molas cerâmicas, sem alterar sua composição ou suas dimensões. Foram produzidos três lotes de molas de alumina, que foram sinterizadas a 1550°C, 1600°C e 1650°C, com o objetivo de verificar os efeitos da temperatura sobre a constante de mola e a tensão de fratura. As molas de alumina sinterizada foram obtidas com densidades variando de 94,0% para 97,5% do limite teórico. As constantes de mola foram medidas desde a temperatura ambiente até 1100°C. Os dados obtidos nos ensaios de fratura sob compressão foram analisados de acordo com a estatística deWeibull e o método da máxima verossimilhança. Com o aumento da temperatura de sinterização, de 1550°C até 1650°C, foi observado que a constante de mola e a resistência característica de Weibull das molas de alumina aumentaram em 15% e 32%, respectivamente. Por outro lado, a temperatura de sinterização não teve muita influência sobre o módulo de Weibull. Isso acontece porque as bolhas internas e os defeitos superficiais introduzidos na fase de conformação das molas cerâmicas, possuem um efeito pronunciado na fratura das molas, mais importante do que a redução da porosidade com o aumento da temperatura de sinterização, e são fundamentais para determinar a resistência à compressão das molas cerâmicas.
Submitted by Marcelo Teixeira (mvteixeira@ucs.br) on 2014-06-05T16:49:28Z No. of bitstreams: 1 Dissertacao Rodrigo Antonio Barbieri.pdf: 4044147 bytes, checksum: 645abe8dc3f878007d2ac1715ded418e (MD5)
Made available in DSpace on 2014-06-05T16:49:28Z (GMT). No. of bitstreams: 1 Dissertacao Rodrigo Antonio Barbieri.pdf: 4044147 bytes, checksum: 645abe8dc3f878007d2ac1715ded418e (MD5)
In this work, ceramic coil springs was prepared by low-pressure injection molding using alumina submicrometer-sized powder. The powder are mixed with organic binders in the Pelstman machine tank for several hours resulting in a mixture with low viscosity. This work include the production of helical ceramic springs, thermal debinding, sintering in different temperatures and measure some properties. Sintering temperature was shown to be a simple way to change the spring constant and resistence to compression of ceramics without having a significant impact in the spring´s physical dimensions. Three sets of springs were sintered at different temperatures, from 1550°C to 1650°C, in order to observe the effects on spring constant and fracture stress. Sintered alumina springs were obtained with densities ranging from 94.0% to 97.5% of the theoretical limit. Springs constants were measured from room temperature up to 1100°C. Fracture stress data was analyzed according to Weibull statistics and the maximum likelihood method. Upon increase of sintering temperature from 1550°C to 1650°C, the spring constant and the Weibull characteristic strength of the alumina springs increases by 15% and 32%, respectively. On the other hand, sintering temperature has a negligible influence on Weibull modulus. This is because internal bubbles and surface defects introduced in the production stage of the ceramic springs - more than the reduction in porosity with increasing sintering temperature - are critical in determining the compression resistance of the ceramic springs.
Gli stili APA, Harvard, Vancouver, ISO e altri
14

Kertész, Tibor. "Optimalizace systémů EGR a vodního vstřikování u zážehového motoru". Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2020. http://www.nusl.cz/ntk/nusl-417474.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
15

Malbois, Pierre. "Analyse expérimentale par diagnostics lasers du mélange kérosène/air et de la combustion swirlée pauvre prémélangée, haute-pression issue d’un injecteur Low-NOx". Thesis, Normandie, 2017. http://www.theses.fr/2017NORMIR25/document.

Testo completo
Abstract (sommario):
Les motoristes aéronautiques misent sur le développement de systèmes d’injection de carburant innovants pour réduire la consommation de carburant et les émissions de polluants. L’objectif de la thèse est de contribuer à l’étude expérimentale d’un injecteur « Lean Premixed » par le développement de diagnostics lasers couplant des approches basées sur la diffusion de Mie et l’émission fluorescente de traceurs. Les mesures ont été réalisées sur le banc de combustion haute pression HERON. Une approche novatrice avec l’imagerie de fluorescence du kérosène a permis d’obtenir une quantification du mélange kérosène/air. La structure de flamme a été mesurée simultanément par PLIF-OH et des mesures PIV de vitesse ont complété cette analyse. Un développement préliminaire de la PLIF-CO a également été mené. Les nombreuses mesures permettent de fournir une analyse détaillée des interactions flamme/spray/aérodynamique lors d’une combustion swirlée stabilisée kérosène/air à haute pression
Aeronautical engine manufacturers are banking on the development of innovative fuel injection systems to reduce fuel consumption and pollutant emissions. The aim of the thesis is to contribute to the experimental investigation of a "Lean Premixed" injector by developing laser diagnostics coupling approaches based on Mie scattering and fluorescent emission of tracers. Measurements are performed at high pressure on the HERON combustion test bench. An innovative approach with fluorescence imaging of kerosene has resulted in the quantification of the kerosene/air mixture. The flame structure was analyzed simultaneously by OH-PLIF and velocity PIV measurements were performed to complete this analysis. A preliminary development of CO-PLIF was also conducted. The numerous measurements provided a detailed analysis of the mechanisms of flame/spray/aerodynamic interactions during a swirl-stabilized kerosene/air combustion at high pressure
Gli stili APA, Harvard, Vancouver, ISO e altri
16

Tsai, Ren-Lung, e 蔡仁隆. "Development and Application for Low-Pressure Wax Injection Rapid Toolings". Thesis, 2015. http://ndltd.ncl.edu.tw/handle/r6cfjc.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
17

Deng, B. Y., e 鄧秉義. "The debinding study of low pressure injection molded ZrO2 compact". Thesis, 1999. http://ndltd.ncl.edu.tw/handle/51480090577371478516.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
18

Saraf, Iqbal Rashid. "Modeling direct liquid injection into low pressure environments and plasmas /". 2008. http://proquest.umi.com/pqdweb?did=1654494061&sid=1&Fmt=2&clientId=10361&RQT=309&VName=PQD.

Testo completo
Gli stili APA, Harvard, Vancouver, ISO e altri
19

許誌宏. "Investigation of Efficiency of Repairing Material for Structural Cracks of Concrete -by Low Pressure Epoxy-Injection Method". Thesis, 2000. http://ndltd.ncl.edu.tw/handle/76235151361230043009.

Testo completo
Abstract (sommario):
碩士
朝陽大學
營建工程系碩士班
88
Abstract Concrete crack always takes place when structures are subjected to excessive loads or exposed in severe environment. There are several crack repairing technique used in concrete construction. Epoxy-injection is the one used mostly in crack repairing; while few research have investigated the crack development as well as the efficiency of reparation for the crack. This research attempts to study the crack propagation and the efficiency of reparation for various crack widths and crack depths. The entire testing program comprises 40 concrete beam specimens, which is classified into two parts. In part I, each beam is pre-cracked in either three-point bending or four-point bending to create a unique flexural crack or shearing crack, respectively. Dye is then used to penetrate into the crack to reveal the crack profile, followed by the injection of epoxy resin to the crack. In part II, beams are pre-notched with various depths and notch widths to simulate the crack. The notched part is filled with epoxy resin and tested. Thus, the effects of crack width and depth of concrete crack to the efficiency of reparation could be observed. On the other hand, a dynamic finite element code, FRANC2D/L, is employed to simulate and predict the crack patterns for flexural and shearing cracks. From the testing results, it is found that shearing crack has the similar crack front as that of flexural crack, namely, the crack on both sides is deeper than that in the middle portion. For the pre-cracked beams, it shows that the efficiency of reparation for deeper crack is getting lower, and the efficiency of reparation for flexural crack attains to 134%, higher than 107% for shearing crack. It is also observed that a new crack face will be created after the old crack is repaired. For the pre-notched beams, it is found that the efficiency of reparation for the notch at 4 mm width has an optimal condition for various depths. Also, the deeper the notch depth, the lower the efficiency of reparation, which is consistent with that found for the pre-cracked beams.
Gli stili APA, Harvard, Vancouver, ISO e altri
20

Hruby, Eric John. "An experimental investigation of a homogeneous charge compression ingnition engine using low pressure injection and diesel fuel". 2003. http://catalog.hathitrust.org/api/volumes/oclc/53142993.html.

Testo completo
Abstract (sommario):
Thesis (M.S.)--University of Wisconsin--Madison, 2003.
Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 126-129).
Gli stili APA, Harvard, Vancouver, ISO e altri
21

Lemiski, Ryan Thomas. "Sedimentology, ichnology, and resource characteristics of the low-permeability Alderson Member, Hatton Gas Pool, southwest Saskatchewan, Canada". Master's thesis, 2010. http://hdl.handle.net/10048/958.

Testo completo
Abstract (sommario):
Thesis (M.Sc.)--University of Alberta, 2010.
Title from PDF file main screen (viewed on July 2, 2010). A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Master of Science, Department of Earth and Atmospheric Sciences, University of Alberta. Includes bibliographical references.
Gli stili APA, Harvard, Vancouver, ISO e altri
22

Su, Sheng-Jie, e 蘇聖傑. "Rapid Manufacturing Technology for Precision Low Pressure Wax Injecting Mold". Thesis, 2012. http://ndltd.ncl.edu.tw/handle/78759220144892972587.

Testo completo
Abstract (sommario):
碩士
明志科技大學
機電工程研究所
100
A low pressure wax injecting mold can be fabricated by use of fused deposition modeling rapid prototyping, whereas, the surface precision of the rapid mold fabricated is not preferred. In the study, a new technique is proposed for rapid manufacturing a low pressure wax injection mold with high surface finish and high dimensional accuracy. In the experiment results, it is found that after padding the wax pattern fabricated by low pressure wax injection mold, the center line average surface roughness Ra value can be improved from 1710 µm to 276 µm, so the surface roughness improvement rate can be reached to 83.85 %. However, the Z axis deviation and wax pattern shrinking deviation problems, can be improved with compensation to enhance size precision. Wax patterns produced from this mold have not only better dimensional accuracy but also better surface finish. The average relative error of dimension of wax patterns can be reduced from 1.76% to 0.66%. Surface roughness improvement rate of wax patterns of up to 85.71% can be achieved. And after 20 times of low pressure wax injecting conducted by low pressure wax injecting mold, there is no shed of padding materials found on the mold surface, through tension test, it is found that the tensile strength between metal resin materials and rapid prototype materials is about 3.86 MPa, the padding coverage method for size of precision low pressure wax injecting mold proposed by the study, is simple, flexible in process, time saving in mold developing, no complex mathematics calculation, design size deviation reduced, low fabrication cost, and preferred size precision. Keywords:Fused Deposition Modeling;A Low Pressure Wax Injection Mold; Dimensional Accuracy;Surface Roughness;Shrinkage
Gli stili APA, Harvard, Vancouver, ISO e altri
23

Sun, Yun-Chiang, e 孫運強. "Analysis of Thermal Flow Field in Vertical Rotating Injector Low Pressure Chemical Vapor Deposition Reactor Using the Directs Simulation Monte Carlo Method". Thesis, 1998. http://ndltd.ncl.edu.tw/handle/47907890823565153955.

Testo completo
Abstract (sommario):
碩士
國立交通大學
機械工程研究所
86
This thesis applies a numerical technique, DSMC, to simulate the thermal flow field in a vertical low-pressure Cu-CVD reactor. It is incorporated with a project supported by a manufacturer and the National Science council, ROC, under a contract, NSC87-2622-E-009-004. The main purpose is to provide the simulation data as a reference for designing the reacting chamber. According to the requirement of the manufacturer, the effects of rotating injector with fixed suscepter are investigated numerically in this thesis. The parametric studies are based on the changes in physical conditions, such as reactor pressure, temperature of substrate, inlet flow rate, angular velocity of rotating injector and carrier gas. The effect of distance between the injector and substrate is also studied. In the meantime, the influence of two different chemical reaction models on the surface deposition of substrate is considered as well.   The results show that a good deposition uniformity for the angular velocities within the domain of 10 to 20 rpm can be achieved. When the reactor pressure increases, the deposition rate increases but the uniformity becomes worse. Increasing the percentage of reactant in precursor can raise the deposition rate more effectively than increasing the reactor pressure. It can also obtain a better deposition uniformity. A higher deposition rate and a better deposition uniformity can be reached by shorting the distance between the injector and substrate. However, an enough distance should be reserved to let the robot arm be able to deliver the wafer into and out from the reacting chamber. When a carrier gas with lower molecular weight is used, a higher deposition rate but with a worse deposition uniformity is found. The high temperature of substrate results in a high temperature in the injector, therefore, the temperature of suscepter suggested not too high in order not to make the reactant deposition on the its aperture to block the transportation of carrier gas and reactants.
Gli stili APA, Harvard, Vancouver, ISO e altri
Offriamo sconti su tutti i piani premium per gli autori le cui opere sono incluse in raccolte letterarie tematiche. Contattaci per ottenere un codice promozionale unico!

Vai alla bibliografia