Dissertations / Theses on the topic 'Compressor stem'
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Yell, M. D. "Steam compression in the single screw compressor." Thesis, University of Leeds, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.372575.
Full textДережук, Михайло Васльович. "Відновлення штоку гідроциліндру плазмовим напиленням." Master's thesis, КПІ ім. Ігоря Сікорського, 2018. https://ela.kpi.ua/handle/123456789/28500.
Full textIn this thesis project the issue related to increase wear resistance of hydraulic cylinder with plasma spraying is indicated. The analysis of the working conditions and the operating of compressor stem has been studied. The technological characteristics of the basic and surfacing materials have been investigated. The technology of restoration that ensures a high-quality formation of the deposited layer, providing the high wear resistant properties, has been developed. In the section on Occupational Health and Safety the issues of enhance electrical and gas safety and improvement of the working conditions of the personnel are highlighted. The note contains 93 pages of typewritten text, 8 figures, 10 tables, 2 appendixes, 15 sources of literature.
Hedges, Collin R. "Computational fluid dynamic model of steam ingestion into a transonic compressor." Thesis, Monterey, Calif. : Naval Postgraduate School, 2009. http://edocs.nps.edu/npspubs/scholarly/theses/2009/Jun/09Jun%5FHedges.pdf.
Full textThesis Advisor(s): Gannon, Anthony J. "June 2009." Author(s) subject terms: Computational Fluid Dynamics, Transonic, Compressor, Steam Ingestion, Sanger Rotor. Description based on title screen as viewed on July 10, 2009. Includes bibliographical references (p. 61). Also available in print.
Levis, William R. "Unsteady casewall pressure measurements in a transonic compressor during steam induced stall." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2006. http://library.nps.navy.mil/uhtbin/hyperion/06Jun%5FLevis.pdf.
Full textHo, Fu-chak, and 何富澤. "Effect of cyclic compression on cytoskeleton remodeling and cell matrix interaction of hMSCs encapsulated in three dimensional type I collagen matrix." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2014. http://hdl.handle.net/10722/197108.
Full textpublished_or_final_version
Mechanical Engineering
Doctoral
Doctor of Philosophy
Villescas, Ivan J. "Flow field surveys in a transonic compressor prior to inlet steam ingestion tests." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2005. http://library.nps.navy.mil/uhtbin/hyperion/05Sep%5FVillescas.pdf.
Full textThesis Advisor(s): Garth Hobson, Anthony Gannon. Includes bibliographical references (p. 57-59). Also available online.
Hurley, Andrew M. "Experimental investigation of high-pressure steam-induced surge in a transonic compressor stage." Thesis, Monterey, Calif. : Naval Postgraduate School, 2008. http://bosun.nps.edu/uhtbin/hyperion-image.exe/08Jun%5FHurley.pdf.
Full textThesis Advisor(s): Gannon, Anthony J. "June 2008." Description based on title screen as viewed on August 25, 2008. Includes bibliographical references (p. 29-30). Also available in print.
Li, Chuen-wai, and 李鑽偉. "Dynamic compression and exogenous fibronectin regulates cell-matrix adhesions and intracellular signaling proteins of human mesenchymal stem cells in 3D collagen environment." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2013. http://hdl.handle.net/10722/197553.
Full textpublished_or_final_version
Mechanical Engineering
Doctoral
Doctor of Philosophy
Payne, Thomas A. "Inlet flow-field measurements of a transonic compressor rotor prior to and during steam-induced rotating stall." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2005. http://library.nps.navy.mil/uhtbin/hyperion/05Dec%5FPayne.pdf.
Full textZarro, Sarah E. "Steady state and transient measurements within a compressor rotor during steam-induced stall at transonic operational speeds." Thesis, Monterey, California. Naval Postgraduate School, 2006. http://hdl.handle.net/10945/2528.
Full textSteam leakage from an aircraft carrier catapult is sometimes ingested into the aircraft engines upon launch which may induce compressor stall. Investigation of this phenomenon is of particular interest to the Navy with its new F35C, the aircraft carrier variant of the joint strike fighter. The single engine configuration of the F-35C makes this aircraft particularly vunerable to steam-induced stall. The present study examined both throttle-induced stall and steam-induced stall in a compressor at 90% and 95% speed through the use of 9 Kulite and 2 hot-film pressure transducers. The use of Fast Fourier Transform waterfall plots of the transient data before and during stall proved invaluable in determining stall precursors as well as the mode of rotor stall. In addition, a new computational fluid dynamic model was designed using CFX-5 software to represent a single blade passage of the compressor rotor, in order to predict compressor performance. The computed results were compared to experimental results gathered at various throttle settings. An accurate model will enable researchers to predict compressor performance for various and multiple gases.
Outstanding Thesis
Phaiboonsilpa, Natthanon. "CHEMICAL CONVERSION OF LIGNOCELLULOSICS AS TREATED BY TWO-STEP SEMI-FLOW HOT-COMPRESSED WATER." Kyoto University, 2010. http://hdl.handle.net/2433/126764.
Full textМірошниченко, Володимир Валерійович, Владимир Валерьевич Мирошниченко, Volodymyr Valeriiovych Miroshnychenko, В`ячеслав Михайлович Арсеньєв, Вячеслав Михайлович Арсеньев, and Viacheslav Mykhailovych Arseniev. "Струйная термокомпрессорная установка для когенерационных энергопреобразующих систем." Thesis, Сумский государственный университет, 2016. http://essuir.sumdu.edu.ua/handle/123456789/45736.
Full textKohut, Vojtěch. "Výroba stlačeného vzduchu v TŽ Třinec." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2011. http://www.nusl.cz/ntk/nusl-229816.
Full textALBUQUERQUE, Carlos Eduardo da Silva. "Avaliação do comportamento energético e exergético de um sistema de refrigeração por compressão de vapor." Universidade Federal de Campina Grande, 2017. http://dspace.sti.ufcg.edu.br:8080/jspui/handle/riufcg/1249.
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CNPq
Esta pesquisa apresenta uma análise energética e exergética de uma unidade de refrigeração de água gelada de grande porte, chamada chiller. O refrigerador em estudo realiza o ciclo termodinâmico de refrigeração com auxílio de um compressor mecânico, usualmente acionado por um motor elétrico, de forma a aumentar a pressão em determinada fase do ciclo termodinâmico do sistema, o que gera um alto consumo de energia elétrica. Com avanço da tecnologia, a cada dia surgem novos tipos de compressores que possuem um menor consumo de energia e melhoram o desempenho da unidade como um todo. O objetivo deste trabalho é avaliar os comportamentos energético e exergético, baseados respectivamente na primeira lei e na segunda lei da termodinâmica, de um chiller que fornece água gelada e trabalha com um compressor tipo parafuso. Este estudo foi realizado baseando-se no comportamento real de um chiller de compressão de vapor, instalado em um shopping da região de João Pessoa-PB. Através de simulação numérica, foi possível avaliar o comportamento do equipamento com a mudança de alguns dos parâmetros normais de trabalho, como pressões de condensação e evaporação, temperatura s de condensação e evaporação e fluido refrigerante. Neste estudo, são apresentados dados do desempenho do equipamento em função das pressões do evaporador e do compressor, da temperatura de evaporação, entre outros parâmetros. Os resultados das simulações, realizadas com auxilio do software EES, mostraram que o desempenho da unidade melhora ao diminuir a variação de pressão entre o condensador e o evaporador e que as eficiências energética e exergética sofrem um acréscimo com o aumento da temperatura de evaporação e uma redução com a elevação da temperatura de condensação.
This research presents energetic and exergetic analysis of a water refrigeration unit, called Chiller. The Chiller under study performs the thermodynamic cycle of the refrigeration with the assistance of a mechanical compressor, usually triggered by an electric motor, in order to increase the pressure in a certain stage on the thermodynamic cycle of the system, which generates high energy consumption. However, with the advance of the technology, every day emergs new types of compressors that have lowest energy consumption and improves the performance of the unit as a whole. The purpose of this work is to evaluate both e nergetic and exergetic behavior, of a chiller that provides cold water and works with a screw type compressor, based on the first and second laws of thermodynamics . This study was based on the actual behavior of a steam compression chiller from a mall in the city of João Pessoa-PB. Through numerical simulation, it was possible to evaluate the behavior of the equipment with the change of some of the normal parameters of work, as condensation and evaporation pressures, condensation and evaporation temperature and refrigerant fluid. In this study, the performance of the equipment data is presented as a function of the evaporator and compressor pressures, the evaporation temperature and other parameters. The results of the simulations, that were realized with support of software EES, showed that the unit performance was improved by decreasing the pressure variation between condenser and the evaporator and also has proved that the energetic and exergetic efficiences are increased by raising the evaporation temperature and a reduction happens by increasing the condensation temperature.
Fritz, Jason Ronald. "The Chondrogenesis of PDLs by Dynamic Unconfined Compression Is Dependent on p42/44 and Not p38 or JNK." Scholarly Repository, 2009. http://scholarlyrepository.miami.edu/oa_theses/225.
Full textTegas, Antonio Vasile. "Finite element modeling of flow/compression-induced deformation of alginate scaffolds for bone tissue engineering." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2016. http://amslaurea.unibo.it/10209/.
Full textКухарев, И. Е., and В. И. Гецман. "Повышение надежности турбины Р-32 компрессора синтез-газа поз. 401 на предприятии ОАО "Минудобрения", г. Россошь." Thesis, Издательство СумГУ, 2011. http://essuir.sumdu.edu.ua/handle/123456789/21540.
Full textThere described modernizing the steam turbine for driving the synthesis – gas compressor of ammonia production, which has been executed by the TRIZ OOO to decrease the vibration levels throughout the rotational speed range of the turbine rotor at the expense of decreasing the distance between the bearings and installing additional damping support При цитировании документа, используйте ссылку http://essuir.sumdu.edu.ua/handle/123456789/21540
Mesnard, Philippe. "Formes d’onde à saut de fréquences et Compressed Sensing : Application à la détection et à la reconnaissance aéroportées." Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLG004.
Full textChanges in the context of airborne radar processing implie more and more improvements that justify to look for an alternative to Matched Filtering, the process conventionally used to estimate the parameters of detected targets. Compressed Sensing suggests a new treatment, also performing in multi-target cases, with better tracking and recognition performances than classical approach. We seek to apply this treatment to step frequency waveforms. The whole choice of definition parameters for the transmitted signal entirely builds the measurement matrix of the Compressed Sensing procedure which solution gives all the sought information of the observed scene. For each step frequency signal with constant amplitude, the resulting measurement matrix is obtained by extracting some lines from a particular extended Fourier matrix, the 2D Fourier matrix. The construction of the measurement matrix generation is important since the success of the reconstruction depends on the algebraic properties of this matrix
Прокопов, Максим Геннадійович, Максим Геннадьевич Прокопов, and Maksym Hennadiiovych Prokopov. "Теплофизическое моделирование рабочего процесса жидкостно-парового струйного компрессора." Thesis, Изд-во СумГУ, 2011. http://essuir.sumdu.edu.ua/handle/123456789/23679.
Full textВ диссертационной работе приведены: теплофизическая модель жидкостно-парового струйного компрессора, результаты анализа экспериментальных исследований вскипающих потоков жидкости в расширяющихся каналах и проточной части жидкостно-парового струйного компрессора, описание формирования трех критических режимов течения и структурной инверсии потока, характеристики компрессора. Представлена математическая модель рабочего процесса, которая позволяет определять параметры и характеристики жидкостно-парового струйного компрессора. Созданная методика инженерного расчета реализована в виде расчетной программы для ЭВМ и позволяет создать компрессор с высокими показателями эффективности. При цитировании документа, используйте ссылку http://essuir.sumdu.edu.ua/handle/123456789/23679
The dissertation presents the results: thermophysical model of liquidsteam stream compressor, results of analysis of experimental researches of boiling up streams of liquid in the broadening ductings and running part of liquid-steam stream compressor, description of forming of three critical modes of flow and structural inversion of stream. The mathematical model of working process, which allows to determine parameters and descriptions of liquid-steam stream compressor, is presented. The created method of engineering calculation is realized as a calculation program for computer and allows to create a compressor highperformance efficiency, descriptions of compressor. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/23679
Sendeski, Mauricio Michalak. "Atividade simpática na hipertensão arterial associada à compressão neurovascular do bulbo rostral ventro-lateral em humanos." Universidade de São Paulo, 2004. http://www.teses.usp.br/teses/disponiveis/5/5160/tde-14102014-092123/.
Full textIntrodution: The prevalence of newborn and infant hearing loss is estimated to range 1.5 to 6 per 1.000 live births and newborn with risk factors for hearing loss range 1.5 to 17%. Objective: To verify the prevalence of newborns and infants hearing loss admitted in the intensive and intermediary care unit; to relate the hearing loss with the presence of risk factors for such event and to determine the wound anatomic level. Methods: It is a prospective cohort study with 71 newborns (NB), in three Hospitals in São Paulo (September 2003 and March 2004). Twenty six (36.62%) NB females and 45 (63.38%) males. The average of the weight and of the gestational age at the birth were 2,480.63 g (825 g-4,215 g) and 36.14 weeks (25.57-41.57 weeks), respectively. The first evaluation using the transient evoked otoacoustic emission during the hospitalization. The second was performed in the ambulatory of the hospital with transient evoked otoacoustic emission and auditory brainstem response. The average of the chronologic age and of the gestacional age at the first evaluation were 19.36 days and 38.86 weeks and at the second evaluation were 73.50 days and 46.61 weeks, respectively. The risk factors for hearing loss evaluated: perinatal, respiratory, infection, metabolic, use of equipment and others (mechanical ventilation duration, use of non-invasive oxygen-therapy, time in the incubator and neonatal in the intensive unit care), ototoxic medications, neurological, renal ins ufficiency and retinopathy of prematurity. The data were evaluated calculating averages and proportions, inferential analysis and concordance test between the first and the second audiologic evaluation. Results: Twenty three (32.39%) NB of the 71 presented a hearing loss, eight (30.77%) females and 15 (33.33%) males. Eleven (47.83%) newborns presented unilateral alteration and 12 (52.17%) bilateral. Fourteen NB (60.87%) presented cochlear alteration, 1 (4.35%) retrocochlear and 8 (34.78%) mixed. The hearing loss was significantly associated with small for gestational age newborns; apnea, hypocalcaemia, administration ototoxic medications, administration of amicacine and furosemida. The concordance test between the first and the second transient evoked otoacoustic emission was weak (k=0.138, 95%confidence interval 0;0.364). Conclusions: The prevalence of hearing loss in this study was high that in the literature. The hearing loss was significantly associated with six risks factors studied. The difference between unilateral and bilateral alteration wasn\'t observed, the cochlear alteration was more frequent, following the mixed and retrocochlear alteration
Fourie, Neil. "Simulating the effect of wind on the performance of axial flow fans in air-cooled steam condenser systems." Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/95977.
Full textENGLISH ABSTRACT: The use of air-cooled steam condensers (ACSCs) is the preferred cooling method in the chemical and power industry due to stringent environmental and water use regulations. The performance of ACSCs is however highly dependent on the influence of windy conditions. Research has shown that the presence of wind reduces the performance of ACSCs. It has been found that cross-winds (wind perpendicular to the longest side of the ACSC) cause distorted inlet flow conditions, particularly at the upstream peripheral fans near the symmetry plane of the ACSC. These fans are subjected to what is referred to as '2-D' wind conditions, which are characterised by flow separation on the upstream edge of the fan inlets. Experimental investigations into inlet flow distortion have simulated these conditions by varying the fan platform height. Low platform heights resulted in higher levels of inlet flow distortion, as also found to exist with high cross-wind speeds. This investigation determines the performance of various fan configurations (representative of configurations used in the South- African power industry) subjected to distorted inlet flow conditions through experimental and numerical investigations. The similarity between platform height and cross-wind effects is also investigated and a correlation between system volumetric effectiveness, platform height and cross-wind velocity is found.
AFRIKAANSE OPSOMMING: Die gebruik van lugverkoelde stoom kondensors (LVSK's) word verkies as 'n verkoelingsmetode in die chemiese- en kragvoorsieningsindustrie as gevolg van streng omgewings- en waterverbruiksregulasies. Die werkverrigting van LVSK's word egter grootliks beïnvloed deur die teenwoordigheid van wind. Navorsing het gewys dat die teenwoordigheid van wind die werkverrigting van LVSK's verminder. Daar was gevind dat kruiswinde (wind loodreg tot die langste sy van die LVSK) versteurde inlaat vloeitoestande veroorsaak, veral by waaiers wat aan die stroomop kant van die LVSK naby die simmetrievlak geleë is. Hierdie waaiers word blootgestel aan na wat verwys word as '2-D' windtoestande wat gekenmerk word deur vloeiwegbreking wat plaasvind by die stroomop rand van die waaierinlate. Eksperimentele ondersoeke van inlaat vloeiversteurings het hierdie toestande gesimuleer deur die waaier platformhoogte te verstel. Lae platform hoogtes het gelei tot hoër vlakke van inlaat vloeiversteuring, soortgelyk aan wat gevind word met hoë kruiswindsnelhede. Hierdie ondersoek gebruik numeriese en eksperimentele metodes om die werkverrigting van verskeie waaierkon gurasies (verteenwoordigend van kon- gurasies wat gebruik word in die Suid-Afrikaanse kragvoorsieningsindustrie) wat blootgestel word aan versteurde inlaat vloeitoestande te bepaal. Die ooreenkoms tussen platformhoogte en kruiswind e ekte word ook ondersoek en 'n korrelasie tussen die sisteem volumetriese e ektiwiteit, platformhoogte en kruiswindsnelheid word bepaal.
Votoupal, Adam. "Parní protitlaková turbína s integrovanou převodovkou pro pohon kompresoru." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2019. http://www.nusl.cz/ntk/nusl-400498.
Full textКозін, Віктор Миколайович, Виктор Николаевич Козин, Viktor Mykolaiovych Kozin, and М. В. Заставенко. "Аналіз ефективності роботи конденсатора повітряного охолодження парокомпресійної холодильної машини." Thesis, Сумський державний університет, 2017. http://essuir.sumdu.edu.ua/handle/123456789/62418.
Full textГоловань, С. В. "Теплонасосна установка з використанням пароструминної термокомпресії." Master's thesis, Сумський державний університет, 2019. http://essuir.sumdu.edu.ua/handle/123456789/76512.
Full textВ работе рассмотрены схемы и принципы действия теплоиспользующих тепловых насосов, к которым относятся абсорбционные, адсорбционные и пароэжекторные насосы. Также выполнен термодинамический анализ пароструйного термотрансформатора, который работает в режиме теплового насоса. В исследовательской части поставленные задачи исследования, разработана теплонасосной установки с использованием пароструйных термокомпрессии и исследованы изменения температуры испарения холодильного агента и температуры на входе в паронагревателя на эффективность ее работы. В конструкторской части выполнен тепловой конструктивный расчет пароструйного эжектора. В разделе охраны труда рассмотрены технике безопасности при эксплуатации холодильного производства, проведения Анализ вредных и опасных факторов холодильного производства, произведен расчет естественного и искусственного освещения.
The work discusses the schemes and principles of operation of heat-using heat pumps, which include absorption, adsorption and steam jet pumps. A thermodynamic analysis of the steam-jet thermotransformer, which operates in the heat pump mode, was also performed. In the research part, the objectives of the study were developed, a heat pump installation using steam-jet thermal compression was developed, and changes in the temperature of evaporation of the refrigerant and the temperature at the inlet of the steam heater on its efficiency were studied. In the design part, the thermal design calculation of the steam-jet ejector was performed. In the section of labor protection, safety measures are considered during operation of the refrigeration industry, analysis of harmful and dangerous factors in the refrigeration industry, calculation of natural and artificial lighting.
Warensjö, Mats. "Compression wood in Scots pine and Norway spruce : distribution in relation to external geometry and the impact on dimensional stability in sawn wood /." Umeå : Swedish University of Agricultural Sciences, 2003. http://diss-epsilon.slu.se/archive/00000415/.
Full textThesis documentation sheet inserted. Appendix includes reprints of five papers and manuscripts, four co-authored with others. Includes bibliographical references. Also issued electronically via World Wide Web in PDF format; online version lacks appendix.
Moraes, Mayara Queiroz. "Contribuição aos estudos da influência da nanossílica nas propriedades mecânicas e na trabalhabilidade de concretos para produção em centrais e para fabricação de pré-moldados." Universidade Federal de Goiás, 2012. http://repositorio.bc.ufg.br/tede/handle/tede/3429.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
Unlike the silica fume, whose benefits on the properties of the concretes are already widely known, little is known regarding nanosilica. This research offers an analysis of the contribution of different types of nanosilica in mechanical characteristics and workability maintenance of concretes, as well as an evaluation of the behavior of these additions when subjected to steam curing. For this, there were compared among themselves laboratory test results in concretes with different characteristics and different purposes (one of them suitable for production at batching plants and the other for metering precast elements). The results confirmed advantages for the simple addition of nanossílica at mechanical properties of concretes for batching plants with strengths above 40 MPa (a/c<0.52), but showed that the most advantageous situation consists in adding it together with sílica fume, since the concrete with both additions exceeded the reference concrete above 36 MPa (a/c<0.615), which highlights the importance of combining pozzolanic effect of silica fume, the creation of nucleation sites caused by nanossílica and better packaging mix, size distribution generated by the two additions give the folder.Regarding the maintenance of workability, the nanosilica dispersed in superplasticizer demonstrated satisfactory performance. In the analysis of concretes for precast elements, the addition of nanosilica dispersed superplasticizer and silica fume together was also the one which showed the best results in terms of resistance in 28 days of conventional curing. However, with steam curing, a great improvement was noted in the behavior of nanosilica dispersed in water, which had not achieved good results with the conventional cure, while nanosilica dispersed in superplasticizer did not respond well to the process, possibly due to the shape of the polycarboxylate used in the dispersion of the particles. Probably, the nanosilica dispersed in water showed no significant pozzolanic activity levels, but with the rise of temperature and the agitation of the particles, the formation of nucleation sites was intensified. As the development of resistance in early ages, all additions had positive effects, but the best performance was observed on the concrete with the simple addition of nanosilica dispersed in superplasticizer. With this addition, the concrete has reached 40 MPa after only 12 hours of steam curing, within about four times lower than the reference concrete (44 hours), which suggests that its addition to the concrete could result in na almost four times greater productivity of a precast elements factory.
Ao contrário da sílica ativa, cujas vantagens nas propriedades do concreto já são amplamente conhecidas, pouco se sabe em relação à nanossílica. Esta pesquisa contempla uma análise da contribuição de diferentes tipos de nanossílica nas características mecânicas e de manutenção do abatimento de concretos, bem como uma avaliação do comportamento destas adições frente à cura térmica. Para isto, compararam-se entre si resultados de ensaios laboratoriais em concretos com diferentes traços e diferentes finalidades (produção em centrais dosadoras e fabricação de pré-moldados). Os resultados confirmaram vantagens para a adição simples de nanossílica quanto à resistência à compressão dos concretos para centrais com resistências acima de 40 MPa (a/c<0,52), mas mostraram que a melhor situação consiste na adição conjunta de sílica ativa e nanossílica, já que o concreto com a adição conjunta superou o de referência a partir de 36 MPa (a/c<0,615). Isso deixa clara a importância de aliar o efeito pozolânico da sílica ativa, a criação de pontos de nucleação ocasionada pela nanossílica e o melhor empacotamento da mistura, gerado pela distribuição granulométrica que as duas adições juntas conferem à pasta. Quanto à manutenção do abatimento, a nanossílica dispersa em aditivo superplastificante demonstrou desempenho satisfatório. Em relação aos concretos para pré-moldados, foi a adição conjunta de sílica ativa e nanossílica dispersa em superplastificante a que apresentou melhores resultados de resistência aos 28 dias de cura convencional. No entanto, com a cura térmica, notou-se melhora substancial do comportamento da nanossílica dispersa em água, que não havia atingido bons resultados com cura convencional, enquanto a nanossílica dispersa em superplastificante não respondeu bem ao processo, possivelmente por influência da forma do policarboxilato usado na dispersão das partículas. Provavelmente, a nanossílica dispersa em água não apresentou atividade pozolânica relevante, mas com a elevação da temperatura e a agitação das partículas, a formação de pontos de nucleação foi intensificada. Quanto ao desenvolvimento de resistências nas idades iniciais, todas as adições apresentaram efeitos positivos, mas o melhor desempenho foi observado no concreto com adição simples da nanossílica dispersa em superplastificante. Com ela, o concreto atingiu 40 MPa com apenas 12 horas de cura térmica, prazo quase quatro vezes menor do que o do concreto de referência (44 horas), o que leva a crer que sua adição ao concreto poderia implicar em uma produtividade quase quatro vezes maior de uma fábrica de elementos pré-moldados.
Лєоньков, Г. А. "Типи холодильних машин." Thesis, Сумський державний університет, 2018. http://essuir.sumdu.edu.ua/handle/123456789/67057.
Full textSantos, Liane Ferreira dos [UNESP]. "A influência do patamar de cura térmica sobre a resistência dos concretos auto-adensáveis elaborados com diferentes tipos de cimento: avaliação pelo método da maturidade." Universidade Estadual Paulista (UNESP), 2010. http://hdl.handle.net/11449/94478.
Full textO concreto auto-adensável (CAA) é um material que representa um dos maiores avanços na tecnologia do concreto das últimas décadas. O desenvolvimento do CAA propiciou eficiência e melhora nas condições de trabalho em canteiro de obras e na indústria de pré-moldados. Do ponto de vista reológico, o CAA é uma mistura fluida que proporciona diferenças de comportamento quando comparado ao concreto convencional. Neste contexto, a proposta desta pesquisa foi estudar, num primeiro plano, as características reológicas nas fases de pasta, argamassa e concreto do CAA no estado fresco e seu comportamento no estado endurecido. Para isso, optouse por empregar a metodologia de Repette e Melo (2005), que considera a resistência à compressão como ponto de partida para a composição do traço do CAA e que estuda os aspectos reológicos envolvidos nas diferentes fases de sua dosagem. Os materiais empregados para estudo de dosagem foram o fíler basáltico como adição, areia média, brita 19 mm, aditivo superplastificante e dois tipos de cimento. Foram elaborados dois concretos, com cimentos distintos, ambos com mesma classe de resistência igual a 40 MPa. Num segundo plano, foi realizado um estudo da avaliação da resistência à compressão desses concretos quando submetidos à cura térmica a vapor, variando-se as temperaturas de cura (entre 65oC e 80oC), assim como o patamar isotérmico de cura em 4 h,6 h e 8 h para cada temperatura. A avaliação das propriedades mecânicas dos concretos foi realizada empregando o Método da Maturidade. No emprego da maturidade foram utilizados as funções de Nurse e Saul e a proposta por Freiesleben-Hansen e Pedersen (FHP). As análises comparativas foram realizadas em função do tipo de cimento empregado, temperatura de cura e tempo de patamar isotérmico
The self-compacting concrete (SCC) is a material that represents one of the greatest advances in concrete technology in recent decades. The development of SCC has resulted in improved efficiency and working conditions at the construction site and the precast industry. Rheological point of view, the SCC is a fluid mix that provides behavior differences when compared to conventional concrete. In this context, the proposal of this research was to study, in the foreground, the rheological phases of paste, mortar and concrete of SCC in the fresh state and its behavior in the hardened state. For this, we chose to employ the methodology Repette e Melo (2005), which considers the compressive strength as a starting point for the composition of the trace of SCC and studying the rheological aspects involved in the different stages of their dosage. The materials used to study the dosage was basalt fillers such as addition, medium sand, gravel 19 mm, superplasticizer additive and two types of cement. We prepared two concretes with different cements, both with the same strength class of 40 MPa. In the background, a study assessing the compressive strength of concrete when subjected to steam curing, varying the curing temperatures (between 65oC and 80oC) as well as the level of isothermal cure at 4 h, 6 h and 8 h for each temperature. The evaluation of mechanical properties of concrete was carried out using the Maturity Method. Employment of maturity was used to Nurse e Saul function, as well as function proposed by Freiesleben-Hansen and Pedersen (FHP). Comparative analysis were performed according to the type of cement used, curing temperature and isothermal plateau
Spáčil, Tomáš. "Bicí automat pro hudebníky." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2014. http://www.nusl.cz/ntk/nusl-220353.
Full textČupera, Pavel. "Trigenerace a její využití v praxi." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2009. http://www.nusl.cz/ntk/nusl-217827.
Full textChou, Yuh-Shan, and 周鈺珊. "Bioactive Constituents from the Stems of Michelia compressa var. formosana." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/48035065274504960504.
Full text輔英科技大學
醫學檢驗生物技術系碩士班
101
Analysis of active ingredient in stems of Michelia compressa var. formosana (Magnoliaceae). Make the sample to dry, cut into small pieces and put into the glass bottle filled with methanol, after concentrated under reduced pressure to give an extracts of methanol. The methanol extracts using column chromatography and thin layer chromatography to made the purified compound, and to the composition and structure of the identification of NMR methods. We isolated seven compounds from the stems of M. compressa var. formosana including: liriodenine (1), (-)-N-acetylanonaine (2), pressalanine A (3), p-hydroxybenzaldehyde (4), 3,4-dihydroxybenzoic acid (5), (-)-bornesitol (6) and β-sitostenone (7). Among them, pressalanine A (3), 3,4-dihydroxybenzoic acid (5) and (-)-bornesitol (6) were isolated for the first time from this species.
Chang, Tung-Yuan, and 張東源. "Compression Properties of Slag Cement Concrete Made by the Dry- Mix/Steam-Injection Procedure." Thesis, 1993. http://ndltd.ncl.edu.tw/handle/27183615093099781434.
Full textJayaprakash, Narayan M. "Shock Wave-boundary Layer Interaction in Supersonic Flow over Compression Ramp and Forward-Facing Step." Thesis, 2014. http://hdl.handle.net/2005/3014.
Full textHamza, Syed Muhammad Farrukh. "Shear-enhanced permeability and poroelastic deformation in unconsolidated sands." Thesis, 2012. http://hdl.handle.net/2152/ETD-UT-2012-08-6353.
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