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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Drift bottle studies at Bodega Head, California

Hamby, Robert Jay 01 January 1965 (has links)
Despite the fact that considerable information now exists on the major oceanic current system, off the Pacific Coast, little is known about the near shore currents in many regions of the west coast states. The Bodega Bay area of California is a case in point. Because of the proposed construction of a nuclear-powered steam plant on Bodega Head and its proximity to both the Pacific Marine Station of the University of the Pacific and to the future marine laboratory of the University of California, it has become necessary to learn as much as possible about the currents in the immediate vicinity of Bodega head. Prior to 1962, few or no current studies were made within the fifty fathom curve off Bodega Bay, although the Pacific Marine Station maintained two oceanographic stations off Bodega Head monthly from 1959 to 1963 as part of the CALCOFI program. One of these stations was at the head of Bodega Canyon, some 25 miles offshore, and the was on the 50 fathom isobath, about five miles offshore. This study describes the results of 28 drift bottle experiments performed from July 1962 to July 1963 in the Bodega Bay region. The point of release of the drift bottles in all experiments except the last three was the cove of Bodega Head about 4000 feet south of Horseshoe Cove. (This cove would be the outfall area for the effluent waters from a power generation plant on Bodega Head.) Two of the other three drift bottle releases were on a line WSW from Bodega Head to the head of Bodega Canyon, while the third release was just north of the mouth of Stemple Creek in Bodega Bay.
32

Effects of feeder, diurnal variation and nipple experience with the same feeder on feeding behavior of premature infants

Erickson, Patricia Ann January 1986 (has links)
This document only includes an excerpt of the corresponding thesis or dissertation. To request a digital scan of the full text, please contact the Ruth Lilly Medical Library's Interlibrary Loan Department (rlmlill@iu.edu).
33

Analytical, Numerical, and Computational Methods to Analyze the Time to Empty Open, Closed, and Variable-Topped Inverted Bottles

Schwefler, Callen 01 June 2021 (has links) (PDF)
Recent unexpected experimental observations of the emptying of inverted bottles with perforations has generated interest in modeling and simulation of this phenomenon. It was observed that as a perforation, i.e., a small hole at the "top" of the inverted bottle, is added and enlarged, the overall emptying time first increases to a maximum value and then decreases until it reaches a lower limit. The change in emptying time is associated with a transition from jetting, where only water exits the neck, to glugging, a competition between air and water flows at the neck of the bottle. This paper develops analytical and numerical models to predict emptying time and liquid height as a function of time which capture the jetting-to-glugging transition. When qualitatively compared to experimental data using a bottle with neck diameters of 12.7 mm, 25.4 mm, and 38.1 mm and bottle diameter of approximately 355 mm (equating to several hundred to several thousand seconds to drain) a favorable agreement is observed. These models attempt to explain the transition in terms of a competition between liquid and bubble velocities at the bottle neck and build on an existing model of glugging available in the literature. The paper also explores the first steps taken toward simulation of bottle emptying using a commercial CFD package (Fluent) to simulate draining for a smaller bottle of neck diameter 21.6 mm and bottle diameter of 62.2 mm. The Fluent simulations are used to further elucidate the jetting-to-glugging transition mechanism by simulating emptying with and without perforations. CFD results reported are limited to a few select large perforation diameters. Specifically, a 4 mm perforation taking 15 hours to simulate and 6 mm perforation taking 5 hours to simulate. Despite the lengthy simulation times, both capture only the approximate 2 seconds required to drain the bottle, but demonstrate the effect of the perforation on emptying time. Smaller perforations on the order of 1 mm, which would align with the experimentally determined maximum emptying time would require unfeasibly long simulations for present resources as dictated by required low Courant numbers. Future work with greater computational capability will further expand upon the simulations conducted in this work.
34

Laminar Plunging Jets - Interfacial Rupture and Inception of Entrainment

Kishore, Aravind 27 October 2014 (has links)
No description available.
35

Transient Crystallization of Poly (ethylene terephthalate) Bottles

Boyd, Timothy J. 25 August 2004 (has links)
No description available.
36

Geology of the Bottle Lake Complex, Maine

Ayuso, Robert A. January 1982 (has links)
The Bottle Lake Complex is a Paleozoic composite granite emplaced near the core of the Merrimack synclinorium in east-central Maine. The two plutons exposed within the Complex are reversely zoned in their mineralogy, major and trace element compositions. Each intrusive exhibits characteristic features including the abundance of amphibole and mafic xenoliths as in the Passadumkeag River granite, and relative abundance of biotite, aplites, and pegmatites in the granite of Whitney Cove. Both display geochemical variations identifying the respective core facies as the least differentiated zones compared to the rims. On the basis of field relations the relative sequence of intrusion is established between the two intrusives, but geochronologic studies using Pb-Pb zircon ages do not display a clear age difference. The granite of Passadumkeag River is, as judged by the field relations, the youngest pluton in the Complex. This granite is also the most heterogeneous body as expressed by petrography, mineral chemistry, and bulk composition. The numerous mafic xenoliths enclosed by the Passadumkeag River pluton display textural, mineralogical, and geochemical variations distinct from those found in the host granitoid rocks. The source of the Bottle Lake Complex was heterogeneous in composition as suggested by the petrology of the granites and xenoliths, and by the wide range in ²³⁸U/²⁰⁴Pb of the batholith. Fractional crystallization accounts for most of the variation within each pluton, although other processes such as mixing of liquids must also be postulated. In the case of the Whitney Cove pluton, mixing occurred prior to the major stage of fractionation. The granite of Passadumkeag River, however, records the mixing of a different batch of liquid during fractionation. Comparison of the geologic relations in the granites of east-central Maine, emplaced across the Merrimack synclinorium indicates that a major discontinuity in the sources of granitic liquid exists on either side of the Norumbega fault system. The Bottle Lake Complex is a distinctive batholith representative of the plutons emplaced in the core of the synclinorium. Together with the nearby Center Pond granite they form a distinct subgroup in comparison to the rest of the plutons on the northside of the Norumbega fault. The lead isotopic compositional variation across the synclinorium is unlike the documented changes present in complex subduction systems such as the Sierra Nevada. This is in agreement with previous geologic studies which suggested an absence of features characteristic of destructive tectonic margins in this area of New England. Granite generation across the synclinorium occurred in a short time interval probably by melting volcaniclastic materials on the north side of the fault, and by melting cratonic detritus on the opposite side. / Ph. D.
37

Synchrony in adult male Atlantic Spotted Dolphins (Stenella frontalis) during aggression

Unknown Date (has links)
Synchrony between Atlantic spotted dolphins (Stenella frontalis) is crucial for successfully fending off bottlenose dolphins (Tursiops truncatus) during interspecies aggression. The present study examined synchrony in adult Atlantic spotted dolphins during aggressive encounters with bottlenose dolphins. Across group size, aggressive behavioral events increased preceding synchrony, peaked during synchrony, and decreased dramatically after synchrony. Although smaller groups (< 10 dolphins) became synchronous more frequently than larger groups (> 10 dolphins), larger groups remained synchronous longer; however, smaller groups exhibited more frequent aggressive behavioral events during synchrony, suggesting that additional aggressive behaviors may be necessary to compensate for the small group size, whereas larger groups may be able to rely on synchrony alone. Disorganized squawk bouts synchronized as physical synchrony began, but only if coupled with escalating aggressive behaviors. The synchrony during aggressive episodes observed in adult Atlantic spotted dolphins can be used as a baseline to determine the process of the development of this critical skill in juveniles. / Includes bibliography. / Thesis (M.A.)--Florida Atlantic University, 2015 / FAU Electronic Theses and Dissertations Collection
38

Endogenous Opioids and Voluntary Ethanol Drinking : Consequences of Postnatal Environmental Influences in Rats

Gustafsson, Lisa January 2007 (has links)
Genetic and environmental factors interact to determine the individual vulnerability to develop ethanol dependence. The neurobiological mechanisms underlying these processes are not fully understood. Endogenous opioid peptides have been suggested to contribute. Brain opioids mediate ethanol reward and reinforcement via actions on the mesocorticolimbic dopamine system. This thesis focuses on environmental factors and investigates the impact of the early-life environment on adult voluntary ethanol consumption. The possible involvement of opioid peptides in environmental influences on adult ethanol consumption was examined using an experimental animal model. Maternal separation with short 15 min separations (MS15) was used to simulate a safe environment whereas prolonged 360 min separations (MS360) simulated an unsafe environment. Control rats were subjected to normal animal facility rearing (AFR). The separations were performed daily from postnatal day 1 to 21. Long-term ethanol consumption was registered using a two-bottle or a four-bottle free-choice paradigm in adult male and female ethanol-preferring AA (Alko, Alcohol), ethanol-avoiding ANA (Alko, Non-Alcohol) and non-preferring Wistar rats. In addition, analyses of immunoreactive Met-enkephalin-Arg6Phe7 (MEAP), dynorphin B (DYNB) and nociceptin/orphanin FQ (N/OFQ) peptide levels were performed after maternal separation as well as after voluntary ethanol drinking. In male rats, MS15 was related to lower ethanol consumption and these rats preferred lower concentrations, whereas MS360 was associated with an increased risk for higher consumption and/or preference for higher ethanol concentrations. Differences in basal opioid levels were observed in MS15 and MS360 rats. Furthermore, the ethanol-induced effects on opioid peptides in adults were dependent on the early environment. Female rats, on the other hand, were less affected or unaffected by maternal separation both in terms of ethanol consumption and neurobiological effects. Taken together, voluntary ethanol drinking, preference for low or high ethanol concentrations and opioid peptides in brain areas related to reward and reinforcement, motivation and stress were influenced by postnatal maternal separation in a sex dependent manner. The early environment thus had profound impact on the adult brain and the individual propensity for high ethanol drinking. A deranged endogenous opioid system contributed to these effects and may act as a mediator for long-term environmental influence on voluntary ethanol consumption.
39

Self-assembly and functionality of polymer bottle brushes on surfaces

Raguzin, Ivan 16 April 2015 (has links) (PDF)
In the past decade there has been a growing interest in one-dimensional (1D) nanostructures, such as nanowires, nanotubes and nanorods, owing to their size-dependent optical and electronic properties and their potential application as building blocks, interconnects and functional components for assembling nanodevices. One of the ways to obtain such architectures is a template-directed synthesis which is practically a straightforward route to 1D nanostructures. In this approach, the template simply serves as a scaffold, within (or around) which a different material is generated in situ and shaped into a nanostructure with its morphology complementary to that of the template. It is generally accepted that template-directed synthesis provides a simple, high-throughput, and cost-effective procedure that also allows the complex topology present on the surface of a template to be duplicated in a single step. In the current work, utilization of the molecular bottle brushes as templates is proposed for the fabrication of conductive nanorods. Their non-spherical macromolecular geometries and lengths up to a few hundred nanometers allow the application of these structures in nanowire synthesis. The variety of molecular bottle brush architectures and their composition enables the adjustment of appropriate conditions for the preparation of conductive materials. Moreover, the ability of the brushes to assemble on a surface under certain conditions provides their usage as building blocks for the preparation of complex conductive networks. Here, the preparation, characterization, and applications of molecular bottle brushes are discussed. Two main goals were pursued. First, to deepen the knowledge in the synthesis of molecular bottle brushes, and to investigate their behavior on the surface. Second, to explore the application of the brushes as templates or building blocks for the formation of conductive nanowires. For the purpose, new ways of molecular brush synthesis by using the “grafting to” approach had to be developed. It was found that the reaction of nucleophilic addition based on pentofluorophenol chemistry and a coupling “click chemistry” reaction can be used to fabricate molecular brushes. Both methods showed efficient results and demonstrated high reactivity of the backbone with the end groups of the side chains. The “click chemistry” approach, however, demonstrated better results considering higher thicknesses of the brushes and, therefore, higher grafting density of the side chains. The “grafting to” together with the “grafting from” methods are very powerful synthetic tools, which can be used in the fabrication of any desired molecular bottle brush architectures. Additionally, complexation of oppositely charged bottle polymer brushes at a single-molecule level using AFM and CryoTEM was experimentally investigated. It was found that polyelectrolyte complexes have “scrambled-egg” morphology, where oppositely charged polymer chains are not oriented parallel to each other but cross each other. Furthermore, molecular bottle brushes were used as templates for the preparation of conductive nanowires. Three approaches for their fabrication were tested. It was found that brushes could easily be covered with various conductive materials, for example conductive polymers or metals. It was showed that for very small, tiny objects as molecular bottle brushes, one can use FIB in order to build up electrodes at its ends. The electrodes could be sputtered with an accuracy of 500 nm and further be used in the determination of the conductivity. The molecular bottle brushes covered with palladium showed the resistance of 50 MΩ, which, regarding the size of the brush, corresponds to a conductivity of one single molecule being ~1 S*cm-1. The obtained conductivity data were in good correlation with the data found in literature. We believe that the molecular bottle brushes have high potential applicability for the building of complex conductive networks. Future refinement of the synthetic methods, combined with improvements in structuring and positioning of objects at the nanoscale, could lead to their implementation in the construction of high-performance electronic devices.
40

Síntese de catalisadores utilizando garrafa pet para a produção de biodiesel. / Synthesis of PET bottle using catalysts for biodiesel production

Souza, Juliana Kelly Dionízio de 17 September 2012 (has links)
Made available in DSpace on 2015-05-14T13:21:19Z (GMT). No. of bitstreams: 1 ArquivoTotal.pdf: 4834263 bytes, checksum: 9a0661df73e9955af44f0e37d15bf261 (MD5) Previous issue date: 2012-09-17 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The heterogeneous catalysis is a promising alternative to solve the environmental problems found in homogeneous catalysis, because it allows the continuous use of the catalyst until its deactivation and minimizes the generation of effluents. Thus, this work aims to synthesize, optimize and evaluate the activity of heterogeneous catalysts, using PET bottles as a starting material in the synthesis of the active phase and SiO2 as catalyst support for the transesterification reaction of soybean oil. The the catalysts were obtained by a impregnating reaction using methanol. The active phase, the catalysts and catalyst support were characterized by X-ray diffraction (XRD), infrared (IR), Raman spectroscopy, scanning electron microscopy (SEM) and EDS, thermal analysis (TG) and measurement surface area (BET). The biodiesels has been synthesized using a molar ratio of 1:9 (soybean oil: methanol), 0,1 g of active phase as catalyst (room temperature) and 1,2 g of the catalysts synthesized at 75 °C, where its kinematic viscosities were measurements. All catalysts were effective in the synthesis of biodiesel because the viscosity reduction of soybean oil used was very significant, indicating that may have occurred the transesterification process, among all biodiesels synthesized the catalyst that stood out was the 30%-K2CO3/70% SiO2, which was obtained greater viscosity reduction at a lower reaction time. The quality tests were made for 1h Bio-30%, which proved be inside the parameters established by the Agência Nacional de Patróleo (ANP). The experiment reuse of the catalyst used in the synthesis of Bio-1h 30%, showed that the catalytic activity is reduced due to possible leaching phenomenon, then preliminary studies have been proposed to study the possible leaching of the active phase. / A catálise heterogênea é uma alternativa promissora para resolver os problemas ambientais encontrados na catálise homogênea, pois permite o uso continuo do catalisador até sua desativação e minimiza a geração de efluentes. Neste sentido, este trabalho visa em sintetizar, otimizar e avaliar a atividade de catalisadores heterogêneos, utilizando a garrafa PET pós-consumo como matéria prima na síntese da fase ativa e SiO2 como suporte catalítico para a reação de transesterificação com óleo de soja. Os catalisadores foram obtidos pela o método de impregnação utilizando o metanol como solvente. A fase ativa, os catalisadores e o suporte catalítico foram caracterizados por difração de raios-X (DRX), espectroscopia na região do infravermelho (IV), espectroscopia Raman, microscopia eletrônica de varredura (MEV) e EDS, análise térmica (TG), e medida de área superficial (BET). Os biodieseis foram sintetizados utilizando uma razão molar de 1:9 (óleo de soja: metanol), 0,1 g da fase ativa como catalisador a temperatura ambiente e 1,2 g dos catalisadores sintetizados a 75 °C, onde suas viscosidades cinemáticas foram medidas. Todos os catalisadores foram efetivos na síntese do biodiesel, pois promoveu a redução de viscosidade do óleo de soja utilizado, no qual mostrou um indicativo que a reação de transesterificação ocorreu, dentre todos os biodieseis sintetizados o catalisador que mais se destacou foi o 30%-K2CO3/70%-SiO2, onde obteve-se a maior redução de viscosidade com um menor tempo reacional. Os testes de qualidade foram feitos para o Bio 1h-30%, o qual mostrou estar dentro dos parâmetros estabelecidos pela Agência Nacional de Petróleo (ANP). O experimento de reuso do catalisador utilizado na síntese do Bio 1h-30%, mostrou que a atividade catalítica é reduzida devido ao possível fenômeno de lixiviação, então estudos preliminares foram propostos para estudar a possível lixiviação da fase ativa.

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