Thesis (M.S.)--Ohio State University, 2008. / Title from first page of PDF file. Includes bibliographical references (p. 57-60).

Thesis (M.Sc.). / Written for the Dept. of Atmospheric and Oceanic Sciences. Title from title page of PDF (viewed 2008/05/13). Includes bibliographical references.

Thesis (Ph. D.)--University of Chicago, 1935. / Lithoprinted. "Private edition, distributed by the University of Chicago libraries, Chicago, Illinois." Includes bibliographical references.

Made available in DSpace on 2014-06-11T19:23:38Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-08-16Bitstream added on 2014-06-13T20:11:12Z : No. of bitstreams: 1 arantes_dm_me_ilha.pdf: 2475222 bytes, checksum: b2ed332ac75e393615c775738ebcb4ca (MD5) / Compressores alternativos herméticos são amplamente utilizados em sistemas de refrigeração por compressão de vapor de pequeno e médio porte. Uma das principais partes deste tipo de compressor é o sistema de válvulas automáticas utilizadas para controlar os processos de sucção e descarga. O estudo experimental ou analítico/numérico destes processos é bastante complexo, principalmente pela presença do problema de interação fluido-estrutura durante o funcionamento das válvulas e pela complexidade geométrica de todo sistema. Este trabalho consiste em uma investigação experimental do problema de interação fluido-estrutura em uma geometria real de válvula tipo palheta muito usada pela indústria de compressores. Uma bancada experimental foi reformada e inicialmente validada com resultados de distribuição de pressão sobre o disco frontal fixo de um difusor radial, uma geometria muito utilizada para modelar válvulas de compressores de refrigeração. Após o teste da bancada, o escoamento neste difusor radial com disco frontal fixo foi estudado para afastamentos adimensionais entre discos variando de 0,01 a 0,09, para uma faixa de número de Reynolds de 2000 a 20000. Além da análise da distribuição de pressão sobre o disco frontal, a área efetiva de força e o coeficiente de descarga também foram estudados. Com o objetivo de analisar a influência da inclinação da palheta no cálculo do coeficiente de descarga, em comparação com os resultados do difusor radial com disco frontal paralelo ao assento, o escoamento na válvula tipo palheta estática, mas inclinada em relação ao assento, foi investigado. Finalmente, o problema de interação fluido estrutura na válvula tipo palheta foi investigado. A posição instantânea da válvula foi medida para números de Reynolds variando de 2000 a 12000 e a frequência... / Hermetic reciprocating compressors are widely used in small and medium size vapor compression refrigeration systems. One of the main parts of this type of compressor is the automatic valve system used for controlling the suction and discharge processes. The experimental or analytical/numerical study of these processes is very complex, mainly because the occurrence of the fluid-structure interaction problem during the operation of the valves and due to the geometric complexity of the whole system. This work consists in an experimental investigation of the fluid-structure interaction problem in an actual geometry of reed type valve largely used by the compressor industry. An experimental setup was refurbished and initially validated with results for pressure distributions on the surface of a fixed frontal disk of a radial diffuser, which is a geometry largely used for modeling refrigeration compressor valves. After testing the experimental setup, the flow through the radial diffuser with fixed frontal disk was studied for dimensionless gaps between disks varying from 0.01 to 0.09, for Reynolds numbers in the range of 2,000 to 20,000. In addition, the effective force area and the discharge coefficient were studied. In order to analyze the influence of the inclination of the reed on the discharge coefficient calculation, in comparison to the results for the radial diffuser with parallel frontal disc, the flow through the static reed, but inclined in relation to the seat, was also investigated. Finally, the fluid-structure interaction problem in the reed valve was investigated through the instantaneous position of the valve and the characteristic frequency of the valve movement for Reynolds numbers varying from 2,000 to 12,000. Besides contributing for the understanding of the flow in valves, the data... (Complete abstract click electronic access below)

AN ABSTRACT OF THE THESIS OF LINDSEY G. ROBERTS, for the Master of Arts degree in Anthropology, presented May 10, 2013, at Southern Illinois University TITLE: A TAPHONOMIC STUDY EXPLORING THE DIFFERENCES IN DECOMPOSITION RATE AND MANNER BETWEEN FROZEN AND NEVER FROZEN DOMESTIC PIGS (Sus scrofa) MAJOR PROFESSOR: Dr. GRETCHEN R. DABBS This research examined differences in decomposition rate and manner of domestic pig subjects (Sus scrofa) in never frozen and previously frozen research conditions. Never frozen subjects and previously frozen subjects were paired and placed in an identical outdoor research environment at the Complex for Forensic Anthropology Research (CFAR) at Southern Illinois University. Extensive quantitative measurements were collected daily: abdominal circumference, total body score, and temperature. Qualitative observations were also taken daily: photographs of subjects, descriptive decomposition stages, and general visual observations concerning insect activity and subject appearance. Necropsies were performed at varying accumulated degree days between 50 and 300 (Celsius). Statistical comparison (paired samples t-tests) of accumulated degree days to three total body scores (TBS) (early decomposition TBS, 9.5 TBS, and advanced decomposition TBS) indicated the rate of decomposition of previously frozen subjects was significantly different than never frozen subjects at both early decomposition TBS and 9.5 TBS (p=0.003 & p=0.002, respectively). Internally, previously frozen subjects displayed less internal putrefaction, less internal color change, less organ distention, and a more dehydrated appearing heart. Externally, previously frozen subjects exhibited overall gray discoloration, increased desiccation, increased oviposition by insects, and nearly non-existent bloat. Internally, never frozen subjects displayed increased putrefaction, more internal color change, increased organ distention, and pleural bubbling around the lungs. Externally, never frozen subjects exhibited normal color change during decomposition, with purple and green discoloration being much more common in these subjects. Bloat was extensive in never frozen subjects. Due to these differences in rate and manner between never frozen and previously frozen subjects, previously frozen subjects should not be used in taphonomic research, as results may not accurately reflect the normal taphonomic condition. In cases of forensic significance, the possibility of freezing should be investigated if the victim displays external gray discoloration, significant external desiccation, decreased internal putrefaction, lack of bloat, and a dehydrated appearing heart.

Made available in DSpace on 2014-06-11T19:26:41Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-06-18Bitstream added on 2014-06-13T18:30:17Z : No. of bitstreams: 1 fujita_e_me_botfca.pdf: 301305 bytes, checksum: b3bd78528e32893a4c17e6e2d923f491 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O presente trabalho teve por objetivo verificar a qualidade e conservação frigorificada dos frutos de buriti. Foram utilizados frutos de buritis provenientes da reserva ecológica de Jalapão próximo do município de Dianópolis no estado de Tocantins. Os frutos foram transportados ao Laboratório de Frutas e Hortaliças, pertencente ao Departamento de Gestão e Tecnologia Agroindustrial, da Faculdade de Ciências Agronômicas - UNESP - Câmpus de Botucatu, SP. Os frutos foram acondicionados em B.O.D. com as respectivas temperaturas 10°C, 12°C, 15°C e com umidade relativa variando entre 60% l 5% e temperatura ambiente variou em torno de 23°C l 5° e umidade relativa variando 80% l 5% de UR. As avaliações foram realizadas a cada três dias, durante 12 dias de armazenamento. As alterações na qualidade pós-colheita foram detectadas por meio das análises de perda de massa, respiração, sólidos solúveis, pH, acidez titulável, Ratio, rendimento de polpa, teor de açúcar total, teor de matéria graxa, teor de proteína bruta e teor de fibra bruta. O delineamento estatístico empregado foi inteiramente casualizado com três repetições por tratamento, para cada um dos cinco tempos de avaliação, utilizando o Teste de Tukey a 5% de probabilidade com auxílio do programa SISVAR 4.6. Nas condições em que os experimentos foram realizados, os resultados permitiram concluir que, a conservação frigorificada se mostrou eficaz em prolongar do período de armazenamento dos frutos em relação a temperatura ambiente aumentando para 6 dias, pois a testemunha foi descartado no dia 6 devido a alta incidência de patógenos impossibilitando o consumo. Os frutos armazenados à 10°C apresentaram a melhor conservação da qualidade pós-colheita. / The purpose of this work was to verify the quality and low-temperature storage of buriti fruits. Buritis coming from the Ecological Reserve from Jalapão near the city of Dianópolis, State of Tocantins - Brazil were used. The fruits were transported to the Laboratório de Frutas e Hortaliças , from the Departamento de Gestão e Tecnologia Agroindustrial , Faculdade de Ciências Agronômicas - UNESP - Campus de Botucatu, SP. The treatments were conditioned in B.O.D. in 10°C, 12°C, 15°C, and this varying about 60% l 5% and environmental temperature, and this varying about 23°C l 5° of 80% l 5% of U.R. The evaluations were accomplished every three days, for 12 days of storage. The alterations in post-harvest quality were detected through the analysis of mass loss, breathing, soluble solids, pH, titrable acidity, Ratio, pulp revenue; total sugar, lipids, protein and fiber. The experimental design was entirely ramdomized with three repetitions for treatment, for each one of the five times of evaluation, using the Tukey's Test at 5% level of probability with the aid of the program SISVAR 4.6. In the conditions that the treatments were accomplished, it may conclude that, the low-temperature storage showed effective in prolonging the period of storage of the fruits in relation to the environmental temperature increasing for 6 days, as the witness was discarded on the 6th day due to the high pathogenic incidence disabling the consumption. The treatment at 12°C presented the best conservation of the post harvest quality in this work.

Orientador: José Luiz Gasche / Banca: Edson Del Rio Vieira / Banca: Luben Cabezas Gomez / Resumo: Compressores alternativos herméticos são amplamente utilizados em sistemas de refrigeração por compressão de vapor de pequeno e médio porte. Uma das principais partes deste tipo de compressor é o sistema de válvulas automáticas utilizadas para controlar os processos de sucção e descarga. O estudo experimental ou analítico/numérico destes processos é bastante complexo, principalmente pela presença do problema de interação fluido-estrutura durante o funcionamento das válvulas e pela complexidade geométrica de todo sistema. Este trabalho consiste em uma investigação experimental do problema de interação fluido-estrutura em uma geometria real de válvula tipo palheta muito usada pela indústria de compressores. Uma bancada experimental foi reformada e inicialmente validada com resultados de distribuição de pressão sobre o disco frontal fixo de um difusor radial, uma geometria muito utilizada para modelar válvulas de compressores de refrigeração. Após o teste da bancada, o escoamento neste difusor radial com disco frontal fixo foi estudado para afastamentos adimensionais entre discos variando de 0,01 a 0,09, para uma faixa de número de Reynolds de 2000 a 20000. Além da análise da distribuição de pressão sobre o disco frontal, a área efetiva de força e o coeficiente de descarga também foram estudados. Com o objetivo de analisar a influência da inclinação da palheta no cálculo do coeficiente de descarga, em comparação com os resultados do difusor radial com disco frontal paralelo ao assento, o escoamento na válvula tipo palheta estática, mas inclinada em relação ao assento, foi investigado. Finalmente, o problema de interação fluido estrutura na válvula tipo palheta foi investigado. A posição instantânea da válvula foi medida para números de Reynolds variando de 2000 a 12000 e a frequência... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Hermetic reciprocating compressors are widely used in small and medium size vapor compression refrigeration systems. One of the main parts of this type of compressor is the automatic valve system used for controlling the suction and discharge processes. The experimental or analytical/numerical study of these processes is very complex, mainly because the occurrence of the fluid-structure interaction problem during the operation of the valves and due to the geometric complexity of the whole system. This work consists in an experimental investigation of the fluid-structure interaction problem in an actual geometry of reed type valve largely used by the compressor industry. An experimental setup was refurbished and initially validated with results for pressure distributions on the surface of a fixed frontal disk of a radial diffuser, which is a geometry largely used for modeling refrigeration compressor valves. After testing the experimental setup, the flow through the radial diffuser with fixed frontal disk was studied for dimensionless gaps between disks varying from 0.01 to 0.09, for Reynolds numbers in the range of 2,000 to 20,000. In addition, the effective force area and the discharge coefficient were studied. In order to analyze the influence of the inclination of the reed on the discharge coefficient calculation, in comparison to the results for the radial diffuser with parallel frontal disc, the flow through the static reed, but inclined in relation to the seat, was also investigated. Finally, the fluid-structure interaction problem in the reed valve was investigated through the instantaneous position of the valve and the characteristic frequency of the valve movement for Reynolds numbers varying from 2,000 to 12,000. Besides contributing for the understanding of the flow in valves, the data... (Complete abstract click electronic access below) / Mestre

No description available.

A multitude of human tissues, such as bones, tendons, or muscles, are characterized by a hierarchical and highly ordered structure. In many cases, the loss of these tissues requires reconstruction using biocompatible replacement materials. In the field of bone replacement, the pore structure of the material has a crucial influence. Anisotropic porosity would have the advantage of facilitating the ingrowth of cells and newly formed blood vessels as well as the transport of nutrients. In this thesis, scaffolds with a highly ordered and anisotropic pore structure were fabricated using unidirectional freezing. Systematic investigations were carried out on biopolymer solutions (alginate and chitosan) to gain a deeper understanding of the freeze-structuring process. The knowledge gained was then applied to the development of anisotropically structured bone substitute materials. Here, the previously existing material platform for anisotropically structured calcium phosphates was extended to low-temperature phases such as calcium deficient hydroxyapatite (CDHA) or the secondary phosphates monetite and brushite. After the implantation of a biomaterial, the inevitably triggered initial immune response plays a key role in the success of a graft, with immune cells such as neutrophils or macrophages being of particular importance. In this thesis, the influence of anisotropically structured alpha-TCP and CDHA scaffolds as well as their unstructured references on human monocytes/macrophages was investigated. Macrophages produced extracellular traps (ETs) due to mineral nanoparticles formed by the binding of phosphate and calcium ions to human platelet lysate. In particular, incubation of alpha-TCP samples in lysate containing cell culture medium resulted in pronounced particle formation and enhanced release of ETs. / Eine Vielzahl menschlicher Gewebe, wie beispielsweise Knochen, Sehnen oder Muskeln, ist durch eine hierarchische und zum Teil hochgradig geordnete Struktur gekennzeichnet. Der beispielsweise durch Unfälle oder Krankheiten bedingte Verlust dieser Gewebe erfordert in vielen Fällen eine Rekonstruktion mit biokompatiblen Ersatzmaterialien. Neben der chemischen Zusammensetzung spielt deren Architektur eine wichtige Rolle für die Geweberegeneration und schließlich den Heilungserfolg des Implantats. Auch im Bereich des Knochenersatzes hat die Porenstruktur des Materials hierauf einen zentralen Einfluss, wobei der Einsatz von Materialien mit anisotroper Porosität neben der strukturellen Nachahmung des Gewebes den Vorteil hätte, dass das Einwachsen von Zellen und neu gebildeten Blutgefäßen sowie der Nährstofftransport erleichtert würden. In der vorliegenden Doktorarbeit wurden anisotrop poröse Scaffolds mit einer hochgradig geordneten Porenstruktur mit Hilfe der Gefrierstrukturierung hergestellt. Hierfür wurde eine in früheren Arbeiten entwickelte Anlage verwendet, um einen definierten Temperaturgradienten in der Probe zur gerichteten Erstarrung zu erzeugen. Der Kern des Systems besteht aus zwei übereinander angeordneten Peltier-Elemente (PEs), zwischen denen sich die Probenlösung befindet. Durch die Variation der PE-Temperaturen kann das Eiskristallwachstum und schließlich die Porenstruktur innerhalb des Biomaterials gezielt beeinflusst und an die Anforderungen einer gewünschten Anwendung angepasst werden. Das Ziel dieser Arbeit war, ein tieferes Verständnis des Gefrierstrukturierungsprozesses zu erlangen und die gewonnenen Erkenntnisse auf die Entwicklung anisotrop poröser Knochenersatzmaterialien zu übertragen. Hierfür wurden in Kapitel 3 zunächst systematische Untersuchungen an Biopolymerlösungen (Alginat und Chitosan) durchgeführt. Dabei konnte gezeigt werden, dass neben dem äußeren Temperaturgradienten auch die Temperaturen der PEs, die Kühlrate sowie Materialeigenschaften wie das Molekulargewicht, die Konzentration und die Viskosität der Lösung die Porenstruktur beeinflussen. Die Temperatur des Gesamtsystems bestimmte sowohl die Kühlrate als auch die Porendurchmesser, so dass höhere Kühlraten zu kleineren Poren führten. Die Porenorientierung konnte hingegen durch den externen Temperaturgradienten beeinflusst werden, wobei die Poren mit steigendem Gradienten zunehmend senkrecht zur Probenoberfläche orientiert ausgerichtet waren. Bestimmte Parameterkonstellationen, wie beispielsweise eine Temperatur der unteren Kühlfläche unterhalb von 60 °C kombiniert mit einer geringen Temperatur des oberen PE sowie eine hohe Viskosität (über 5 Pas nahe 0 °C) der Vorlösung führten allerdings dazu, dass die Porenausrichtung nicht mehr kontrollierbar war. Auf Basis von Kapitel 4 konnte die bis dato für anisotrop strukturierte Calciumphosphate existierende Materialplattform auf Niedrigtemperaturphasen wie calciumarmen Hydroxylapatit (CDHA) oder die sekundären Phosphate Monetit und Bruschit erweitert werden. Hierfür wurde gesintertes oder ungesintertes -Tricalciumphosphat (-TCP) mit anisotroper Porenstruktur durch hydrothermale Behandlung oder Inkubation in Phosphorsäure in die oben genannten Phasen umgewandelt. Durch die hydrothermale Behandlung konnte sowohl bei ungesinterten als auch bei gesinterten -TCP-Proben eine Phasenumwandlung in CDHA erzielt werden. Die Inkubation in Phosphorsäure führte zu einer Umwandlung in Monetit und Bruschit. Durch die hydrothermale Behandlung für 72 h bei 175 °C erhöhte sich die Porosität der ungesinterten Proben geringfügig von 85 % auf 88 %, während bei den gesinterten Proben ein Anstieg von 75 % auf 88 % zu beobachten war. Darüber hinaus ging eine Phasenumwandlung in CDHA durch die Bildung von feinen Kristallnadeln und -plättchen mit einer Vergrößerung der spezifischen Oberfläche einher. Hinsichtlich der mechanischen Eigenschaften war besonders bemerkenswert, dass die Druckfestigkeit der ungesinterten Proben durch die Phasenumwandlung in Monetit signifikant von (0.76  0.11) auf (5.29  0.94) MPa erhöht wurde. In Kapitel 5 wurde der Einfluss von anisotrop porösen -TCP und CDHA Scaffolds sowie unstrukturierten und aus den gleichen Calciumphosphatphasen bestehenden Referenzproben auf humane Monozyten/Makrophagen untersucht. Nach der Implantation eines Biomaterials spielt die unweigerlich ausgelöste erste Immunreaktion eine Schlüsselrolle für den Erfolg eines Transplantats, wobei Immunzellen wie Neutrophile oder Makrophagen eine entscheidende Rolle spielen. Makrophagen können zur Immobilisierung und zum Abtöten von Mikroorganismen extrazelluläre Fasern (ETs) produzieren. Während in früheren Arbeiten nachgewiesen werden konnte, dass Neutrophile als Reaktion auf Biomaterialien ETs produzieren können, wurde dieser Mechanismus für Makrophagen erstmals in der vorliegenden Doktorarbeit gezeigt. Die ET-Freisetzung wurde von mineralischen Nanopartikeln ausgelöst, welche durch die Bindung von Phosphat- und Calciumionen an menschliches Thrombozytenlysat gebildet wurden. Insbesondere die Inkubation von  TCP Proben in lysathaltigem Zellkulturmedium führte zu einer ausgeprägten Partikelformierung und schließlich zu einer verstärkten Bildung von ETs. Dies ging mit einer erhöhten Freisetzung von pro-inflammatorischen Zytokinen im Vergleich zu CDHA einher. An diese Arbeit anschließende Experimente könnten beispielsweise die Wiederholung von systematischen Studien, wie sie in Kapitel 3 für Biopolymere vorgestellt wurden, mit synthetischen Polymeren wie Polyvinylalkohol (PVA) umfassen. PVA ist ein für den Einsatz als Kryoprotektor vielversprechendes Material, dessen Verwendung für die Kryokonservierung von biologischen Materialien zwingend notwendig ist. Darüber hinaus wäre die Durchführung von in vivo Experimenten erforderlich, um die starke Freisetzung von ETs durch Makrophagen als Reaktion auf strukturierte -TCP Scaffolds sowie die geringere Expression auf CDHA Scaffolds eingehender zu analysieren.

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