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Aplicação da nova técnica de Solution Blow-Spinning (SBS) na produção de fios cerâmicos supercondutores nanométricos dos sistemas (TR)BCO e BSCCO / Application of the new technique Solution Blow-Spinning (SBS) in the production of nanometric superconductor ceramic wire of the systems (TR)BCO and BSCCORotta, Maycon 05 February 2018 (has links)
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Previous issue date: 2018-02-05 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / As propriedades diferenciadas de materiais nanoestruturados, provenientes do efeito de escala, tem chamado muita atenção nos últimos anos. Tais características, fazem desses materiais propícios para o emprego em nanoeletrônica, nanofiltração, engenharia tecidual e outros. Isso, aliado a miniaturização dos dispositivos, tem gerado uma grande demanda por materiais com características aprimoradas, desenvolvimento de novas técnicas de produção e aprimoramento das já existentes, tudo isso associado a um menor custo de produção e uma maior produtividade. Neste trabalho é apresentado um estudo sobre o emprego da técnica de “Solution Blow-spinning” (SBS) na produção de nano e microfios supercondutores dos sistemas cerâmicos (TR)BCO e BSCCO. Esta recente técnica tem se destacado por apresentar maior taxa de produção, baixo custo e fácil implementação quando comparado com técnicas já consolidadas. Primeiramente foram produzidas fibras de PVP puro onde foi possível extrair informações referentes às variáveis de produção tais como: taxa de injeção, pressão do ar, distância de trabalho e escolha do diâmetro da agulha interna. Em seguida, a produção dos nano/microfios de YBa2Cu3O7- δ (YBCO) obtidos por SBS revelaram detalhes referente à produtividade, reprodutibilidade e das características morfológicas dos fios cerâmicos obtidos com o emprego da referida técnica. Posteriormente, as melhores condições de síntese observadas na produção do YBCO foram utilizadas na obtenção dos nano/microfios supercondutores de GdBa2Cu3O7- δ (GdBCO)e Bi2Sr2CaCu2O8+x (BSCCO). Por fim, as análises de MEV confirmaram a obtenção de nano/microfios de YBCO com diâmetro médio de 359 nm e, para GdBCO e BSCCO, de 531 nm e 635 nm respectivamente. A obtenção das fases cerâmicas supercondutoras é mostrada nas análises de DRX. Medidas magnéticas AC e DC mostraram a transição de fase normal/supercondutora com Tc ~ 92 K para o YBCO, Tc ~ 93 K para o GdBCO e de Tc ~ 80 K para o BSCCO. / The single properties presented by nanostructured materials is due to a scale effect and have been attracted much attention in recent years. Such characteristics make these materials suitable for applications in nanoelectronics, nanofiltration, tissue engineering and so on. These issues coupled with the miniaturization of the devices, have generated a great demand for materials with improved characteristics, development of new production techniques and improvement of the existing ones. All such things are associated with lower production costs and higher productivity. In this work is presented a study focused on the use of the "Solution Blow-spinning" technique (SBS) in the production of superconducting nano and microwires of the ceramic systems (TR)BCO and BSCCO. This new technique has payed attention due to its higher production rate, low cost and easy implementation when compared to other consolidated techniques. First, pure PVP fibers were produced to obtain information related to the production variables such as: injection rate, air pressure, working distance and choice of the internal needle diameter. Then, the production of nano/microwires of YBa2Cu3O7- δ (YBCO), obtained by SBS, revealed details regarding the productivity, reproducibility and morphological characteristics of the ceramic wires. Consequently, the best synthesis conditions were used to obtain the GdBa2Cu3O7- δ (GdBCO) and Bi2Sr2CaCu2O8+x (BSCCO) superconducting nanowires. Finally, SEM analysis confirmed the production of nanoscale YBCO with average diameter of 359 nm and, for GdBCO and BSCCO, of 531 nm and 635 nm, respectively. The formation of the desired phases of the superconducting ceramic was confirmed by XRD analyzes. AC and DC magnetic measurements showed the normal/superconducting phase transition with Tc ~ 92 K for YBCO, Tc ~ 93 K for GdBCO and Tc ~ 80 K for BSCCO. / 1459610
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Reconstrução orbitária com implantes Medpor®: estudo histomorfológico e imunohistoquímico / Reconstruction of the orbital floor with Medpor®: histomorphological and Immunohistochemical analysis in ratsFerreira, Ana Carulina Rezende de Moraes [UNESP] 08 March 2017 (has links)
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Previous issue date: 2017-03-08 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Entre os materiais aloplásticos, o Medpor® apresentou um aumento consideravel no uso de 17% a 30%, portanto o objetivo desse trabalho foi avaliar a utilização do Medpor® na reconstrução do assoalho orbitário. Foram utilizados 18 ratos que sofreram trauma cirúrgico no assoalho orbitário, simulando uma fratura tipo "blow-out". O lado direito do animal recebeu implante de Medpor® e o lado esquerdo não recebeu qualquer tipo de material. Nos períodos de 15, 40 e 90 dias foram realizadas as eutanásias e obtenção das peças para processamento histológico e imunohistoquímico. Os cortes obtidos foram corados com hematoxilina e eosina, tricrômico de Masson e marcação imunohistoquímica nos períodos de 15, 40 e 90 dias com a osteocalcina e RUNX2. O processo de reparo no lado controle finalizou com neoformação óssea aos 40 dias e perda do contorno ósseo inicial, criando um defeito no assoalho de órbita. O grupo tratado mostrou prevalência de tecido conjuntivo em contato com o implante de Medpor®, tanto em sua periferia quanto no seu interior. Não houve processo inflamatório intenso e ou agudo junto ao material. A imunomarcação mostrou escores intensos de OC após 15 dias de pós- operatórios e manteve expressão moderada após 40 e 90 dias pós-operatório, a RUNX2 foi moderadamente expressa em todos os períodos avaliados. Concluimos que o polietileno poroso (Medpor®) é um biomaterial bionert seguro e eficaz, a sua presença levou ao reparo ósseo local e compensou a ausência de tecido ósseo na sustentação do globo ocular. / The aim of this research was to assessed histological and immunohistochemi cal properties in the use of porous polyethylene (Medpor®) for orbital floor reconstruction. Under general anesthesia 18 male rats (Rattus, norvegicus, albinus, Wistar) underwent bilateral surgical defect, simulating blowout fracture and infraorbital rim. Groups were divided as follow: GI control group and GII surgical defects were reconstructed with Medpor®. After 15, 40, and 90 days animals were euthanized with anesthetic overdose. Orbital specimens were laboratorial process, coronal slices were stained in Hematoxylin and Eosin and Masson trichrome. Immunohistochemical assess of osteocalcin (OC) and Corebinding factor alpha1 (Cbfa1) were performed. Bone repair at the control group was achieved after 40 days with loss of the orbital rim and lack of ocular support. Immunolabeling showed intense scores of OC after 15 days post-operative and maintain moderate expression after 40 and 90 days postoperative, Cbfa1 was moderately express within all the periods evaluated. Medpor® group showed fibrous tissue in contact with the implant in the inner and outer surface, without newbone formation and without intense inflammatory infiltrate nearby the biomaterial, the Medpor® gave enough support for the ocularglobe.
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Obtenção e caracterização de mantas fibrosas de poli(fluoreto de vinilideno) (PVDF) com poli(o-metoxianilina) (POMA) pela técnica de "Solution Blow Spinning" /Oliveira, Danilo de Freitas. January 2016 (has links)
Orientador: José Antonio Malmonge / Resumo: Micro e nanofibras poliméricas têm despertado grande interesse de pesquisadores devido as suas potencialidades em diversas aplicações, atribuídas principalmente à grande área superficial destes materiais em associação com as propriedades dos polímeros. Uma das técnicas utilizadas para produção de micro e nanofibras é a solution blow spinning (SBS), ou fiação por sopro em solução. Neste trabalho foram obtidas microfibras de blendas de Poli(fluoreto de Vinilideno) (PVDF) e Poli(o-metoxianilina) (POMA), com a POMA em seu estado dopado e não dopado, pela técnica SBS. Para a dopagem da POMA foi utilizado o ácido p-toluenosulfônico (TSA). Obteve-se mantas com concentrações de PVDF/POMA-TSA de até 85/15 (m/mtotal), e de até 90/10 (m/mtotal) para PVDF/POMA. Foi possível observar a partir das imagens de MEV que os diâmetros médios das fibras diminuíram com o aumento da concentração de POMA, chegando a 0,22 µm para a maior proporção. Essa variação no diâmetro das microfibras é atribuído a variação da viscosidade da solução que diminui com o conteúdo da POMA na blenda. Os difratogramas de raios X indicaram que tanto a fase α quanto a fase β do PVDF foram obtidas no processo de fiação tanto para o PVDF puro bem como para a blendas, mostrando que o conteúdo de POMA na blenda não altera a fase do PVDF. A condutividade elétrica das fibras aumentou significativamente com a porcentagem de POMA (dopada) na blenda, elevando os valores em até 8 ordens de grandeza e atingindo uma condutividade ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Micro and polymeric nanofiber have arisen great interest of researchers because of their potential in various applications, mainly attributed to the large surface area of these materials in association to the properties of polymers and polymer blends. One of the techniques used for producing micro and nanofibres is the solution blow spinning (SBS). In this study microfibers of poly (vinylidene fluoride) (PVDF) and poly (o-methoxyaniline) (POMA) blends were obtained, with POMA in its doped and undoped state, by SBS technique. For POMA doping it was used p-toluenesulfonic acid (TSA). Mats with PVDF / POMA-TSA concentrations of 85/15 (m /mtotal), and up to 90/10 (m /mtotal) to PVDF / POMA were obtained. It was possible to observe from SEM images that the average fiber diameters decreased with increasing concentration of POMA, reaching 0,22μm at the highest proportion. The X-ray diffractograms showed that both α phase and β phase of PVDF were obtained in the spinning process. Such phases didn’t have their formation affected by the variations on the bend concentration. The electrical conductivity of the fibers increased significantly with the percentage of POMA (doped) in the blend, increasing values up to 108 orders of magnitude and reaching a conductivity of about 10-4 S/cm for the mats of PVDF/POMA on the reason 85/15. Furthermore, the mats of the blend showed good thermal stability up to the temperature of 200 °C. / Mestre
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Development of HDPE fuel tanksShelley, R. M. January 1987 (has links)
Plastics fuel tanks have been used successfully abroad ; metal counterparts are still predominant in this country plastics tanks have to satisfy stringent performance regulations : low temperature impact tests ; permeability ; and fire resistance. Blow moulded high density polyethylene (HDPE) fuel tanks have superior strength to mass ratio compared with metal equivalents (the density of steel is about 8000 kg/m3 compared with HDPE, which has a density of under 1000 kg/m3 ). HDPE will tend to drip in a fire situation, thus reducing explosion risk. HDPE is the chosen material because it possesses inherent properties suitable for the blow moulding process : it has a high viscosity at low stresses ; and is highly inert. Rotational moulded HDPE fuel tanks can also be considered. However, these are shown to have inferior properties when compared with blow moulded tanks ; attraction of rotational moulding is the cheapness of equipment. Petrol immersion was found to enhance impact properties of HDPE, although yield stresses were lowered slightly. The thickness distributions of blow moulded fuel tanks were found to vary ; this is because of the present difficulty of predicting parison behaviour with respect to time. Thickness is important because of impact strength and permeation considerations. Impact properties of fuel tanks were assessed ; peak force of impact was found to be heavily dependent on thickness (raised to the power 1.1) and temperature of mould in the blow moulding process (a low mould temperature led to inferior properties). Pinch-offs were found to be particularly detrimental to impact properties. Cooling behaviour was investigated. With the aid of a cooling model for blow mouldings, it was found that a warm mould (40·C) could be used with internal air circulation to obtain a cooling time the same as that with a cold mould and no air circulation. Thus optimising mechanical strength and maintaining economic viability. Welding of injection moulded fittings to the main blow moulded body of the fuel tank was found to be faulty, in all of the tanks examined ; many weld failures have been reported in use. This work determines optimum welding conditions for HDPE grades, these are Rigidex H060-45P and Lupolen 426l-A.
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Insect Signature Indicating Corpse Movement From Urban to Rural Areas of Northeast OhioHans, Krystal R. 21 January 2011 (has links)
No description available.
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Mechanical behavior of Polyethylene Terephthalate and its application to the Reheat Stretch Blow Molding processSistla, Srinath 13 September 2010 (has links)
No description available.
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Dynamics of Lean Direct Injection CombustorsAradhey, Yogesh Sachin 10 November 2023 (has links)
Improvements to heritage gas turbine engines will be needed in the coming years as the demand made on these systems increase. While industry continually presses for higher performance of both military and civilian aero engines, the government simultaneously raises the bar for emissions standards in the commercial sector to support public health. The next generation of aerospace gas turbine engines will be defined by their ability to operate at high power conditions while maintaining efficiency. This challenge is compounded by airlines' proposition of a return to supersonic flight- an operating regime characterized by higher total temperatures, and thus more NOx production.
Lean Direct Injection (LDI) is a combustion scheme that was proposed by NASA, and inherently addresses the needs of both the private sector and the military. LDI is a liquid fueled combustor that promotes rapid mixing of fuel and air at the entrance of the combustor. Despite the benefits of LDI, it has never been implemented, nor has any other lean burning scheme been implemented in an aircraft due to the system level complications of such technology. This dissertation focuses on the dynamics of thermoacoustic instability and lean blowout (LBO), two of the major complications that industry will face when they attempt to incorporate LDI in a production engine.
The present dissertation investigates these dynamics from a fundamental and applications standpoint. Fundamental insights on thermoacoustic instabilities are developed by investigating droplet dynamics in a self-excited flow field, and significant oscillations in droplet diameters are discerned. PDPA measurement will be taken to identify coupling of the fuel spray with the instability, and a phase locking algorithm will be used to develop a new spray parameter than is more indicative of combustion heat release that the standard Sauter mean diameter.
Next, while varying the swirl number and the venturi geometry of the combustor, the evolution of the flow field will be characterized. An in-house innovation called the Direct Rotation Swirler (DRS) is built for this purpose. The DRS uses an active geometry to provide continuously variable swirl number modulation. The effects of these changes on lean blow out, pressure drop and NOx emissions will then be experimentally determined. Venturis were rapidly manufactured using a ii casting procedure that was developed to make venturi geometries from a commercially available ceramic at very low cost. / Doctor of Philosophy / Improvements to heritage gas turbine engines will be needed in the coming years as the demand made on these systems increase. While industry continually presses for higher performance of both military and civilian aero engines, the government simultaneously raises the bar for emissions standards in the commercial sector to support public health. The next generation of aerospace gas turbine engines will be defined by their ability to operate at high power conditions while maintaining efficiency. This challenge in compounded by airlines' proposition of a return to supersonic flight- an operating regime characterized by higher total temperatures, and thus more NOx production.
Lean Direct Injection (LDI) is a combustion scheme that was proposed by NASA, and inherently addresses the needs of both the private sector and the military. LDI is a liquid fueled combustor that promotes rapid mixing of fuel and air at the entrance of the combustor. Rapid mixing yields a clean, even flame and eliminates the fuel-rich primary zone which is the heart of NOx production.
Despite the benefits of LDI, it has never been implemented, nor has any other lean burning scheme been implemented in an aircraft due to the system level complications of such technology. This dissertation focuses on two of the major complications that industry will face when they attempt to incorporate LDI in a production engine. Drastically reducing the local hot spots in the primary zone is fundamentally necessary to improve pattern factor and emissions, but this change is directly at odds with two dynamic phenomenon that plague combustors. These effects are thermoacoustic instabilities, and lean blow out.
Thermoacoustic instabilities are a major concern in any type of combustor and instabilities are more common and more intense in lean engines which is a significant safety risk to aircraft. A thermoacoustic instability occurs when pressure waves in an engine grow to high amplitudes.
Small pressure waves are normal in any combustion process, but when the acoustic waves couple with the heat release, the waves can grow uncontrollably. The amplitudes can reach magnitudes capable of damaging the combustor or significantly reducing its cyclic life. Due to the high iv standard of safety in the aerospace industry, lean combustion will not be implemented until engines can be designed to avoid instabilities throughout the entire flight envelope.
Lean blow out occurs when the fuel to air ratio of the engine becomes too low to sustain a flame.
Lean blow out is a transient phenomenon that is dependent on local flame speeds, local chemical time scales and turbulence parameters. Typically, lean blow out is combated by designing a rich flame anchoring region that burns with plenty of excess fuel so that even if the fuel flow rate is reduced, a core region is still within its flammability regions.
The present dissertation investigates these dynamics from a fundamental and applications standpoint. Fundamental insights on thermoacoustic instabilities are developed by investigating droplet dynamics in a self-excited flow field, and significant oscillations in droplet diameters are discerned. PDPA measurement will be taken to identify coupling of the fuel spray with the instability, and a phase locking algorithm will be used to develop a new spray parameter than is more indicative of combustion heat release that the standard Sauter mean diameter.
Next, while varying the swirl number and the venturi geometry of the combustor, the evolution of the flow field will be characterized. An in-house innovation called the Direct Rotation Swirler (DRS) is built for this purpose. The DRS uses an active geometry to provide continuously variable swirl number modulation. The effects of these changes on lean blow out, pressure drop and NOx emissions will then be experimentally determined. Venturis were rapidly manufactured using a casting procedure that was developed to make venturi geometries from a commercially available ceramic at very low cost.
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Nocturnal light and temperature influences on necrophagous, carrion-associating blow fly species (Diptera: Calliphoridae) of forensic importance in Central TexasKirkpatrick, Ryan Scott 15 November 2004 (has links)
It is commonly thought that blow flies are nocturnally inactive. Blowflies are often important in helping to estimate post mortem intervals (PMI) for corpses found at death scenes. If blow flies oviposit during nocturnal hours, there could possibly be up to 12-hour discrepancies for estimates of PMI.
Two blow fly species, Phaenicia eximia (Wiedemann) and Cochliomyia macellaria (F.), oviposited nocturnally on ground beef baits in 2003, during the onset of low-atmospheric pressure (an air mass with lower atmospheric pressure than that of the air surrounding it) at rural study sites near Snook (Burleson County), Texas, under artificial lighting of at least 1500 footcandles when temperatures were at 26?C or higher. Trials conducted under similar conditions during the same year without a low-pressure system moving into the area resulted in no nocturnal blow fly oviposition.
Nocturnal blow fly oviposition went undetected once low-atmospheric pressure systems settled into the study area, irrespective of temperature and lighting conditions. Thus, this study illustrates that there is a connection between the onset of low-atmospheric pressure and nocturnal blow fly oviposition on baits under artificial lighting of 1500 footcandles or more when temperatures are 26 ?C or above.
After concluding 2003 experiments, statistical analyses supplied evidence that woodland habitat was more favorable for blow fly oviposition than prairieland habitat throughout the 2003 study, irrespective of species or time of year. Furthermore, statistical analyses conducted on nocturnal and diurnal temperature ranges furnished evidence to support the hypothesis that 2003 nocturnal temperatures had more of an effect on daily ovipositing than diurnal temperatures for P. eximia and Cynomyopsis cadaverina (Robineau-Desvoidy).
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„Koncept-dizaino” plano parengimas įdiegiant „Blow-Fill-Seal” aseptinę technologiją akių lašams gaminti / Create „Blow-Fill-Seal" aseptic technology „Concept-design" for eye drops production planŽukauskas, Petras 30 June 2014 (has links)
Darbo tikslas: Išsiaiškinti „Blow-Fill-Seal” technologijos pritaikymo galimybes gaminant akių lašus, sukurti koncepcinį planą įtraukiant patalpų išplanavimą ir galimą sąmatą. Darbo uždaviniai: 1. Pateikti gamybinės linijos proceso pasiūlymą pritaikant technologiją; 2. Sudaryti patalpų planą pritaikant akių lašų gamybą, nurodyti medžiagų ir personalo judėjimą patalpose; 3. Pateikti siūlymus įrengiant švarias patalpas (architektūriniai, vandens tiekimo ir kt. sprendimai); 4. Pateikti technologinių įrengimų pasiūlymus, injekcinio vandens tiekimą; 5. Pateikti galimą projekto sąmatą. Tyrimo metodai apima aktualią literatūros apžvalgą, rekomendacijų, įvairių praktikų, nuostatų bei reglamentų analizę koncentruojantis ties akių lašų gamyba, aseptinių procesų ir su jais susijusių kitų sistemų ar procesų įrengimu, paruošimu bei valdymu, teorinio projektavimo pagrindais. Rezultatuose išskiriamas akivaizdus technologijos praktinio pritaikymo efektyvumas gaminant akių lašus aseptinėmis sąlygomis. Juose patvirtinama ir koncepcinio plano svarba, esmė - tai privalomas elementas, kuris nuo pat pradžių privalo būti teisingas. Išvadose išskiriamas technologijos našumas ir efektyvumas. Taip pat pažymimi planai, jų atlikimo svarba įrengiant patalpas. Naudojamos medžiagos įrengiant švarias patalpas turi būti aukščiausios kokybės, nesukelti papildomų rūpesčių užtikrinant švarą jose. Pasiūlyti įsigyti įrengimai. Projekto sąmata siekia 19,082,000Lt. / Scope: real time use of „Blow-Fill-Seal“ technology in producing ophthalmological preparations, create concept plan including detail room planning and estimated cost layout. Tasks: 1. Suggest a production line using this technology; 2. Create area plan with all rooms designed for making eye drops production, point raw materials and personnel movement; 3. Suggest materials used in creating clean rooms (architectural, water supply etc. solutions); 4. Suggest needed technological apparatus, water for injection supply; 5. Calculate possible estimate. Research methods include review on topical literature, recommendations, practices, statutes and regulations analysis based on liquid ophthalmological preparations‘ processing, aseptic processes‘ and related systems or other processes‘ installation, preparation and controlling, basic and theoretical projection. This technology has obvious practical effectiveness when using it for aseptic eye drops production. Also, the importance and essence of concept design is shown – it is a obligatory element, which has to be correct from the very beginning. Work concludes main technological productivity and effectiveness, notices of area planning importance when creating concept plan. All materials used in clean rooms should be high-end products ensuring safe and clean working space. Technological and other apparatus proposal. Project would approximately estimate 19,082,000Lt.
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TORIC VARIETIES AND COBORDISMWilfong, Andrew 01 January 2013 (has links)
A long-standing problem in cobordism theory has been to find convenient manifolds to represent cobordism classes. For example, in the late 1950's, Hirzebruch asked which complex cobordism classes can be represented by smooth connected algebraic varieties. This question is still open. Progress can be made on this and related problems by studying certain convenient connected algebraic varieties, namely smooth projective toric varieties. The primary focus of this dissertation is to determine which complex cobordism classes can be represented by smooth projective toric varieties. A complete answer is given up to dimension six, and a partial answer is described in dimension eight. In addition, the role of smooth projective toric varieties in the polynomial ring structure of complex cobordism is examined. More specifically, smooth projective toric varieties are constructed as polynomial ring generators in most dimensions, and evidence is presented suggesting that a smooth projective toric variety can be chosen as a polynomial generator in every dimension. Finally, toric varieties with an additional fiber bundle structure are used to study some manifolds in oriented cobordism. In particular, manifolds with certain fiber bundle structures are shown to all be cobordant to zero in the oriented cobordism ring.
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