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1
Chapagain, Narayan P. "Dynamics of Equatorial Spread F Using Ground-Based Optical and Radar Measurements." DigitalCommons@USU, 2011. https://digitalcommons.usu.edu/etd/897.
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The Earth's equatorial ionosphere most often shows the occurrence of large plasma density and velocity fluctuations with a broad range of scale sizes and amplitudes. These night time ionospheric irregularities in the F-region are commonly referred to as equatorial spread F (ESF) or plasma bubbles (EPBs). This dissertation focuses on analysis of ground-based optical and radar measurements to investigate the development and dynamics of ESF, which can significantly disrupt radio communication and GPS navigation systems. OI (630.0 nm) airglow image data were obtained by the Utah State University all-sky CCD camera, primarily during the equinox period, from three different longitudinal sectors under similar solar flux conditions: Christmas Island in the Central Pacific Ocean, Ascension Island in South Atlantic, and Brasilia and Cariri in Brazil. Well-defined magnetic field-aligned depletions were observed from each of these sites enabling detailed measurements of their morphology and dynamics. These data have also been used to investigate day-to-day and longitudinal variations in the evolution and distribution of the plasma bubbles, and their nocturnal zonal drift velocities. In particular, comparative optical measurements at different longitudinal sectors illustrated interesting findings. During the post midnight period, the data from Christmas Island consistently showed nearly constant eastward bubble velocity at a much higher value (~80 m/s) than expected, while data from Ascension Island exhibited a most unusual shear motion of the bubble structure, up to 55 m/s, on one occasion with westward drift at low latitude and eastward at higher latitudes, evident within the field of view of the camera.
In addition, long-term radar observations during 1996-2006 from Jicamarca, Peru have been used to study the climatology of post-sunset ESF irregularities. Results showed that the spread F onset times did not change much with solar flux and that their onset heights increased linearly from solar minimum to solar maximum. On average, radar plume onset occurred earlier with increasing solar flux, and plume onset and peak altitudes increased with solar activity. The F-region upward drift velocities that precede spread F onset increased from solar minimum to solar maximum, and were approximately proportional to the maximum prereversal drift peak velocities.
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Pelon, Floriane. "Fibroblastic heterogeneity and metastatic spread in breast cancers Fibroblast heterogeneity drives metastatic spread in breast cancer through distinct mechanisms." Thesis, Sorbonne Paris Cité, 2018. https://wo.app.u-paris.fr/cgi-bin/WebObjects/TheseWeb.woa/wa/show?t=2392&f=17330.
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Les cancers du sein, premiers cancers féminins et causes aujourd’hui encore de nombreux décès, sont classés en 3 sous-types moléculaires : luminaux –les plus répandus, HER2 et triple-négatifs (TN) –les plus agressifs. Lors du diagnostic, l’envahissement des ganglions lymphatiques axillaires par les cellules tumorales est établi. Il s’agit, en plus de la classification moléculaire, d’un marqueur pronostique utilisé en clinique pour stratifier les patientes, car il informe sur le risque de développement ultérieur de métastases, cause majeure des décès à l’heure actuelle. Les tumeurs solides, et notamment les cancers du sein, sont des écosystèmes complexes comprenant de nombreux types cellulaires qui interagissent avec les cellules cancéreuses. Parmi eux, les fibroblastes associés au cancer (CAF) sont les plus abondants et participent activement à de nombreux aspects de la tumorigenèse dont la croissance, l’invasion, l’angiogenèse, l’immunosuppression. Cependant, ils constituent une population hétérogène et à ce jour, très peu d’études ont analysé cette hétérogénéité tout en la liant aux diverses fonctions décrites des CAF. Dans ce projet, nous nous sommes intéressés au rôle de cette hétérogénéité fibroblastique dans la dissémination métastatique des cancers du sein. En combinant l’étude de plusieurs marqueurs de CAF, nous avons montré que les ganglions lymphatiques envahis par les cellules tumorales sont constitués de 4 sous-populations de CAF (CAF-S1, S2, S3 et S4), similaires à celles identifiées dans les tumeurs primaires appariées. De façon intéressante, ce sont les deux sous-types de CAF myofibroblastiques (αSMA+), CAF-S1 et particulièrement CAF-S4, qui s’accumulent préférentiellement dans les ganglions métastatiques. Ils présentent les mêmes signatures transcriptomiques entre les deux localisations tissulaires (ganglions envahis et tumeurs primaires correspondantes). Or, ces deux populations CAF-S1 et CAF-S4 augmentent le phénotype invasif des cellules tumorales, en régulant des fonctions complémentaires. D’un côté, les CAF-S1 sont hautement motiles, et stimulent la prolifération, la migration, l’invasion et l’initiation d’une transition épithélio-mésenchymateuse des cellules de cancer du sein. De l’autre, les CAF-S4 sont très contractiles, capables de remodeler la matrice extracellulaire et promeuvent ainsi l’invasion et la motilité des cellules tumorales dans des systèmes en 3 dimensions. Des expériences fonctionnelles suggèrent que l’action des CAF-S1 implique CXCL12 et TGFβ tandis que celle des CAF-S4 dépend de la voie NOTCH. En accord avec ces résultats, l’accumulation des CAF et leur identité dans les ganglions envahis constituent deux nouveaux facteurs pronostics dans les cancers du sein, indépendants du sous-type de cancers du sein et de l’envahissement ganglionnaire. En effet, un fort contenu en CAF-S4 y est associé avec un développement ultérieur de métastases à longue distance. Ainsi, analyser le contenu fibroblastique des ganglions axillaires au diagnostic pourrait constituer une information nouvelle et utile à la prise en charge des patientesBreast cancers are the most common cancers in women and despite great improvements in treatments, they are still responsible for many deaths worldwide. They are classified into 3 main molecular subtypes: Luminal cancers are the most frequent ones, while HER2 and TN are the most aggressive. At diagnostic, lymph node involvement is also assessed as it constitutes, in addition to molecular classification, a strong prognostic marker. Indeed, it informs on the risk to develop further distant metastases, which is the main cause of death by cancer. Solid tumors, including breast cancers, are complex ecologies comprising numerous different cell types that interact with cancer cells. Among them, cancer-associated-fibroblasts (CAF) are the most abundant and actively participate in many tumor hallmarks such as tumor growth, invasion, immunosuppression and angiogenesis. However, they do not constitute a homogeneous population but so far, only few studies have characterized this heterogeneity and linked it to CAF previously described functions. In this project, we focused on the potential involvement of CAF heterogeneity in breast cancer metastatic spread. Combining the analysis of several CAF markers, we showed that invaded LN comprise 4 CAF subsets (CAF-S1, S2, S3 and S4), similar to those found in primary tumors. Interestingly, the two myofibroblastic subsets (αSMA+) CAF-S1 and especially CAF-S4 preferentially accumulate in metastatic LN and present the same transcriptomic profiles in both tumors and LN. Importantly, both CAF-S1 and CAF-S4 display pro-invasive properties, by acting at different levels on tumor cells. On the one hand, highly motile CAF-S1 stimulate breast cancer cell proliferation, migration and EMT initiation. On the other hand, CAF-S4 exhibit an important contractility and by remodeling the matrix they are able to promote tumor cell invasion in 3D. Functional studies highlight a CXCL12/TGFβ involvement in CAF-S1 functions while CAF-S4 pro-invasive phenotype appears to be Notch-dependent. In agreement with these data, we found that CAF accumulation and subset enrichment in involved LN were two new prognostic factors, independent of breast cancer molecular subtypes and LN status at diagnosis. Indeed, stromal rich LN with a predominance of CAF-S4 are associated with long distance metastases development and poor overall survival. Thus, we propose that analyzing LN fibroblastic content at diagnosis could constitute new and useful information to breast cancer patients’ care
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Paradza, Masimba Wellington. "Development of a neural network based model for predicting the occurrence of spread F within the Brazilian sector." Thesis, Rhodes University, 2009. http://hdl.handle.net/10962/d1005245.
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Spread F is a phenomenon of the ionosphere in which the pulses returned from the ionosphere are of a much greater duration than the transmitted ones. The occurrence of spread F can be predicted using the technique of Neural Networks (NNs). This thesis presents the development and evaluation of NN based models (two single station models and a regional model) for predicting the occurrence of spread F over selected stations within the Brazilian sector. The input space for the NNs included the day number (seasonal variation), hour (diurnal variation), sunspot number (measure of the solar activity), magnetic index (measure of the magnetic activity) and magnetic position (latitude, magnetic declination and inclination). Twelve years of spread F data measured during 1978 to 1989 inclusively at the equatorial site Fortaleza and low latitude site Cachoeira Paulista are used in the development of an input space and NN architecture for the NN models. Spread F data that is believed to be related to plasma bubble developments (range spread F) were used in the development of the models while those associated with narrow spectrum irregularities that occur near the F layer (frequency spread F) were excluded. The results of the models show the dependency of the probability of spread F as a function of local time, season and latitude. The models also illustrate some characteristics of spread F such as the onset and peak occurrence of spread F as a function of distance from the equator. Results from these models are presented in this thesis and compared to measured data and to modelled data obtained with an empirical model developed for the same purpose.
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Küsgen, Jörg. "Entwicklung von Kreditrisikopreisen und externen Ratings : eine systematische Überblicksanalyse /." Hamburg : Diplomica Verl, 2007. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=015791521&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
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Wolff, Jürgen. "Eine Intermarket-Analyse der Komponenten der Geld-Brief-Spanne : am Beispiel des deutschen Aktienmarktes /." Wiesbaden : Dt. Univ.-Verl, 2003. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=016960607&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
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Küster-Simić, André. "Orderbuchtransparenz, Bietverhalten und Liquidität /." Wiesbaden : Dt. Univ.-Verl, 2001. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=009498556&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
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Thompson, G. "The Effects of Navel Orange Prorate Suspension on F. O. B. to Retail Price Spreads." College of Agriculture, University of Arizona (Tucson, AZ), 1988. http://hdl.handle.net/10150/215711.
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The effects of the navel orange prorate suspension on packinghouse to retail price spreads are analyzed When compared with price spreads for the 1986 season, F.o.b.-retail price spreads declined for Atlanta and San Francisco, but increased for Dallas.
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Hjertberg, Jenny. ""Ja fast fler sanningar kontra att försöka sprida ett budskap det är ju två olika saker tycker jag" : En studie om lågstadielärares historieförståelse." Thesis, Högskolan Dalarna, Pedagogiskt arbete, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:du-24019.
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Syftet med den här studien var att synliggöra F-3 lärares historieförståelse. Ambitionen med detta synliggörande var att bidra med en fördjupad insikt om potentialen av F-3 lärares historieförståelse vad gäller möjligheter att främja elevers tolerans och kritiska förmåga. Studiens syfte och frågeställningar besvarades med hjälp av kvalitativ metod i form av intervjuer med F-3 lärare som undervisar i historia. Data analyserades med inspiration av en fenomenografisk ansats och med teorier om en historieförståelse utifrån perspektivets och sammanhangets betydelse och Rüsens typologi om olika funktioner av berättande. Resultatet tyder på att hälften av de studerade lärarna har en traditionell historieförståelse, vilket betyder att historia framställs som något faktiskt och statiskt. Resterande lärare kan relateras till en genetisk historieförståelse, vilket betyder att historia betraktas utifrån flera perspektiv och sammanhang. Med en sådan historieförståelse är det möjligt att främja elevers tolerans och kritiska tänkande då flera förståelser framhävs. Detta talar för att låta elever möta historia som utgår från en genetisk förståelse redan i lågstadiet, eftersom det är i grundskolans tidigare år som grunden för all utveckling läggs.SO
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Costa, Juliana Nascimento da. "Estudo da estabilidade de maracujà (Passiflora edulis Sims f. flavicarpa degener) em pÃ, proveniente de cultivo orgÃnico." Universidade Federal do CearÃ, 2012. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=8523.
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FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgicoO maracujà à um fruto originÃrio da AmÃrica Tropical, sendo cultivado em paÃses de climas tropical e subtropical, pertencente à famÃlia Passifloraceae, gÃnero Passiflora. O Brasil à o maior produtor mundial de maracujÃ, sendo o maracujÃ-amarelo ou azedo, o mais cultivado, tendo sua produÃÃo voltada ao consumo in natura e à industrializaÃÃo. Dentre os mÃtodos de cultivo do maracujÃ, tem-se a produÃÃo pelo sistema orgÃnico, ainda incipiente no Brasil, no entanto, jà existe grande demanda, principalmente no mercado Europeu, se tornando uma prÃtica cada vez mais comum, visando aliar qualidade de produtos alimentÃcios com a preservaÃÃo ambiental. O MaracujÃ-amarelo à muito apreciado na alimentaÃÃo humana pelo seu sabor intenso e aroma exÃtico, no entanto, a sua elevada perecibilidade dificulta o aumento da vida pÃs-colheita e armazenamento in natura dos frutos. Considerando as tendÃncias atuais por alimentos nutritivos e de rÃpido preparo, a sua utilizaÃÃo sob a forma desidratada, consiste em uma interessante alternativa para a reduÃÃo de perdas, agregar valor ao produto e proporcionar outras maneiras de consumo da fruta. Com base nessas informaÃÃes, o objetivo do trabalho à avaliar a estabilidade do pà de maracujà amarelo, proveniente de cultivo orgÃnico, obtido por spray drying, durante armazenamento por 360 dias, sob temperatura ambiente (Â25ÂC), caracterizando-o quanto aos aspectos fÃsico-quÃmicos, quÃmicos e microbiolÃgicos, acompanhando assim a qualidade desse produto ao longo de sua vida de prateleira. O produto em pà orgÃnico foi cedido por uma empresa processadora de frutos, localizada em Ubajara/CE. ApÃs o processamento as amostras foram levadas para o LaboratÃrio de Frutos e HortaliÃas e Microbiologia de Alimentos do DTA/CCA/UFC em Fortaleza, CE, onde foram mantidas à temperatura ambiente (Â25ÂC) durante os procedimentos analÃticos. Os pÃs de maracujà foram avaliados a cada 30 dias, durante 360 dias de armazenamento, quanto aos seguintes parÃmetros: pH, sÃlidos solÃveis, acidez titulÃvel, SS/AT, atividade de Ãgua, umidade, cinzas, higroscopicidade, solubilidade, aÃÃcares solÃveis totais, aÃÃcares redutores, coordenadas de cor L* a*, b*, croma (c*) e hue ( h*), flavonÃides-amarelos, polifenÃis extraÃveis totais, clorofila total, Ãcido ascÃrbico e β-caroteno. O pà de maracujà orgÃnico manteve-se praticamente estÃvel durante os 360 dias de armazenamento, sob temperatura ambiente (Â25ÂC), oferecendo um grande potencial de utilizaÃÃo, por apresentar adequada retenÃÃo de Ãcido ascÃrbico, higroscopicidade desejada, baixa atividade de Ãgua, pH Ãcido estÃvel, altos teores de cinzas, aÃÃcares, polifenÃis extraÃveis totais e resultados microbiolÃgicos satisfatÃrios, estando o produto sob Ãtimas condiÃÃes higiÃnico-sanitÃrias, apto para o consumo humano.
Passion fruit is a fruit which originates from Tropical America, is cultivated in countries with tropical and subtropical climates, and belongs to the Passifloracea family and Passiflora genus. Brazil is the largest producer of passion fruit in the world, and yellow or sour passion fruit is the most cultivated. Its production has focused on in natura consumption and industrialization. Among the methods of cultivation of passion fruit, the organic production system stands out. It is still incipient in Brazil, but there is great demand, especially in the European market, as it is becoming a common practice in order to combine food quality with environmental preservation. The yellow passion fruit is highly appreciated for the intense flavor and exotic aroma of this fruit, but it has high perishability which makes it difficult to increase the postharvest life and storage of in natura fruits. Considering the current trends in nutritional foods, which canbe prepared quickly their use in dehydrated form is an interesting alternative to reduce losses, add value to the product and provide other ways consume the fruit. Based on this information, the study aims to evaluate the stability of the passion fruit powder from organic cultivation, obtained by spray drying, during 360 days of storage at room temperature (Â25ÂC), characterizing it as to the physical-chemical, chemical and microbiological aspects, monitoring the quality of the product throughout its shelf life. The organic powder product was obtained from a fruit processing company, located in Ubajara, Ceara, north-east Brazil. After processing, the samples were taken to the Fruits and Vegetables Laboratory and to Food Microbiology Laboratory of DTA/CCA/UFC in Fortaleza, where they were kept at room temperature (Â25ÂC) during the analytical procedures. The passion fruit powder was evaluated every 30 days during 360 days of storage, for the following parameters: pH, soluble solids, titratable acidity, SS/AT, water activity, moisture, ash, hygroscopicity, solubility, soluble sugars, reducers sugars, color coordinates L*, a*, b*, chroma (c*) and Hue (H*), total anthocyanins, yellow flavonoids, total extractable polyphenols, total chlorophyll, ascorbic acid and β-carotene. The passion fruit powder remained stable during 360 days of storage at room temperature (Â25ÂC), offering a great potential for use. It presented adequate retention of ascorbic acid, hygroscopicity desired, low water activity, acid pH stable, high levels of ash, sugars, total extractable polyphenols and satisfactory microbiological result so that the product was in optimum hygienic and sanitary condition, fit for human consumption.
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Sepret, Virginie. "Application de la PIV sur traceurs fluorescents à l'étude de l'entraînement d'air par un spray Diesel. Influence de la densité ambiante et du diamètre de trou d'injecteur." Thesis, Toulouse, INPT, 2009. http://www.theses.fr/2009INPT015H/document.
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Le développement actuel des moteurs doit répondre à une volonté de réduction de la consommation et à des normes de plus en plus sévères. Les moteurs Diesel, bien que performants, présentent des émissions trop importantes d'oxydes d'azote (NOx) et de particules de suies. Ces émissions polluantes proviennent essentiellement de l'existence de zones riches en carburant ne permettant pas une combustion optimale. La préparation du mélange air / carburant, fortement conditionné par l'entraînement d'air par le spray est donc essentielle. La Vélocimétrie par Images de Particules sur traceurs Fluorescents, associée à un traitement spécifique des champs de vitesses instantanés de la phase gazeuse externe sont utilisés afin d'obtenir des mesures en proche frontière du spray. Dans la zone quasi statique du spray, un effet important de la densité ambiante sur le taux de mélange est mis en évidence. D'autre part, la diminution du diamètre de trou d'injecteur améliore sensiblement le taux de mélange local. Pour compléter cette analyse, un gain du taux de mélange entre les deux injecteurs est calculé pour chaque densité ambiante. Pour les fortes densités, le gain issu de la réduction du diamètre de trou peut at! teindre une valeur importante (> 60%). La phase gazeuse latérale dans la zone instationnaire du spray est ensuite investiguée et la méthodologie de la F-PIV est transposée à cette zone. Un lien entre la longueur de pénétration du spray et des longueurs d'entraînement est défini. La densité ambiante n'a pas d'effet sur ces longueurs d'entraînement. La diminution du diamètre de trou engendre une augmentation du gaz entraîné à une distance plus courte du nez de l'injecteur. Cependant, cette étude montre que les deux sprays n'engendrent pas un entraînement de gaz similaireThe actual development of the engine must reply to a will of fuel consumption reduction and to stricter norms concerning the pollutant emissions. Although the Diesel engines are competitive, the NOx and soot particle emissions mainly come from the existence of wealthy fuel zone preventing an optimal combustion. Therefore, the air / fuel mixing preparation, highly controlled by the air entrainment in spray, is essential. Particle Image Velocimetry on fluorescent tracers, associated with a specific processing of the instantaneous velocity fields have been applied to obtain measurements in the near vicinity of the spray edge. In the "quasi- teady" region of the spray, the important effect of the ambient density on the mixing rate has been pointed out. On the other hand, an orifice diameter decrease significantly improves the local air / fuel ratio. To complete this analyse, a gain in mixing rate between two different injectors has! been calculated for each gas density. For high densities, the gain due to a reduction of the hole diameter can reach important value (> 60%). Then, lateral gaseous phase in no stationary zone of spray is studying and F-PIV method is transposed to this zone. A link between the penetration length and entrainment lengths is defined. Ambient density has not effect on entrainment lengths. The hole diameter decrease generates entrained gas increase at shorter distance of injector nozzle. However, this study shows two sprays do not generated the same gas entrainment
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Costa, Juliana Nascimento da. "Estudo da estabilidade de maracujá (Passiflora edulis Sims f. flavicarpa degener) em pó, proveniente de cultivo orgânico." reponame:Repositório Institucional da UFC, 2012. http://www.repositorio.ufc.br/handle/riufc/17627.
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COSTA, Juliana Nascimento da. Estudo da estabilidade de maracujá (Passiflora edulis Sims f. flavicarpa degener) em pó, proveniente de cultivo orgânico. 2012. 102 f. : Dissertação (mestrado) - Universidade Federal do Ceará, Centro de Ciências Agrárias, Departamento de Tecnologia de Alimentos, Fortaleza-CE, 2012Submitted by Nádja Goes (nmoraissoares@gmail.com) on 2016-06-13T14:51:33Z No. of bitstreams: 1 2012_dis_jncosta.pdf: 1435585 bytes, checksum: eb5291d8ef0324a23ea00217a03a5373 (MD5)
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Passion fruit is a fruit which originates from Tropical America, is cultivated in countries with tropical and subtropical climates, and belongs to the Passifloracea family and Passiflora genus. Brazil is the largest producer of passion fruit in the world, and yellow or sour passion fruit is the most cultivated. Its production has focused on in natura consumption and industrialization. Among the methods of cultivation of passion fruit, the organic production system stands out. It is still incipient in Brazil, but there is great demand, especially in the European market, as it is becoming a common practice in order to combine food quality with environmental preservation. The yellow passion fruit is highly appreciated for the intense flavor and exotic aroma of this fruit, but it has high perishability which makes it difficult to increase the postharvest life and storage of in natura fruits. Considering the current trends in nutritional foods, which canbe prepared quickly their use in dehydrated form is an interesting alternative to reduce losses, add value to the product and provide other ways consume the fruit. Based on this information, the study aims to evaluate the stability of the passion fruit powder from organic cultivation, obtained by spray drying, during 360 days of storage at room temperature (±25ºC), characterizing it as to the physical-chemical, chemical and microbiological aspects, monitoring the quality of the product throughout its shelf life. The organic powder product was obtained from a fruit processing company, located in Ubajara, Ceara, north-east Brazil. After processing, the samples were taken to the Fruits and Vegetables Laboratory and to Food Microbiology Laboratory of DTA/CCA/UFC in Fortaleza, where they were kept at room temperature (±25°C) during the analytical procedures. The passion fruit powder was evaluated every 30 days during 360 days of storage, for the following parameters: pH, soluble solids, titratable acidity, SS/AT, water activity, moisture, ash, hygroscopicity, solubility, soluble sugars, reducers sugars, color coordinates L*, a*, b*, chroma (c*) and Hue (H*), total anthocyanins, yellow flavonoids, total extractable polyphenols, total chlorophyll, ascorbic acid and β-carotene. The passion fruit powder remained stable during 360 days of storage at room temperature (±25ºC), offering a great potential for use. It presented adequate retention of ascorbic acid, hygroscopicity desired, low water activity, acid pH stable, high levels of ash, sugars, total extractable polyphenols and satisfactory microbiological result so that the product was in optimum hygienic and sanitary condition, fit for human consumption.
O maracujá é um fruto originário da América Tropical, sendo cultivado em países de climas tropical e subtropical, pertencente à família Passifloraceae, gênero Passiflora. O Brasil é o maior produtor mundial de maracujá, sendo o maracujá-amarelo ou azedo, o mais cultivado, tendo sua produção voltada ao consumo in natura e à industrialização. Dentre os métodos de cultivo do maracujá, tem-se a produção pelo sistema orgânico, ainda incipiente no Brasil, no entanto, já existe grande demanda, principalmente no mercado Europeu, se tornando uma prática cada vez mais comum, visando aliar qualidade de produtos alimentícios com a preservação ambiental. O Maracujá-amarelo é muito apreciado na alimentação humana pelo seu sabor intenso e aroma exótico, no entanto, a sua elevada perecibilidade dificulta o aumento da vida pós-colheita e armazenamento in natura dos frutos. Considerando as tendências atuais por alimentos nutritivos e de rápido preparo, a sua utilização sob a forma desidratada, consiste em uma interessante alternativa para a redução de perdas, agregar valor ao produto e proporcionar outras maneiras de consumo da fruta. Com base nessas informações, o objetivo do trabalho é avaliar a estabilidade do pó de maracujá amarelo, proveniente de cultivo orgânico, obtido por spray drying, durante armazenamento por 360 dias, sob temperatura ambiente (±25ºC), caracterizando-o quanto aos aspectos físico-químicos, químicos e microbiológicos, acompanhando assim a qualidade desse produto ao longo de sua vida de prateleira. O produto em pó orgânico foi cedido por uma empresa processadora de frutos, localizada em Ubajara/CE. Após o processamento as amostras foram levadas para o Laboratório de Frutos e Hortaliças e Microbiologia de Alimentos do DTA/CCA/UFC em Fortaleza, CE, onde foram mantidas à temperatura ambiente (±25ºC) durante os procedimentos analíticos. Os pós de maracujá foram avaliados a cada 30 dias, durante 360 dias de armazenamento, quanto aos seguintes parâmetros: pH, sólidos solúveis, acidez titulável, SS/AT, atividade de água, umidade, cinzas, higroscopicidade, solubilidade, açúcares solúveis totais, açúcares redutores, coordenadas de cor L* a*, b*, croma (c*) e hue ( h*), flavonóides-amarelos, polifenóis extraíveis totais, clorofila total, ácido ascórbico e β-caroteno. O pó de maracujá orgânico manteve-se praticamente estável durante os 360 dias de armazenamento, sob temperatura ambiente (±25ºC), oferecendo um grande potencial de utilização, por apresentar adequada retenção de ácido ascórbico, higroscopicidade desejada, baixa atividade de água, pH ácido estável, altos teores de cinzas, açúcares, polifenóis extraíveis totais e resultados microbiológicos satisfatórios, estando o produto sob ótimas condições higiênico-sanitárias, apto para o consumo humano.
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Lima, Francisco Marcone. "DeposiÃÃo de DiÃxido de Estanho-FlÃor (SnO2:F) em Substrato Transparente para Uso em CÃlulas FotoeletroquÃmicas." Universidade Federal do CearÃ, 2013. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=9667.
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FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgicoVidros condutores tÃm sido usados como Ãxidos condutores transparentes (OCTâs). Por causa da transmitÃncia na regiÃo visÃvel e baixa resistÃncia de filme os OCTâs tÃm sido usados como componente de cÃlulas fotoeletroquÃmicas ativadas por corante. Neste trabalho à feito vidros condutores, em escala de laboratÃrio, de dimensÃes 2,6 cm x 7,6 cm pela tÃcnica âspray pyrolysisâ, os vidros condutores sÃo aplicados na construÃÃo da cÃlula fotoeletroquÃmica com eletrodos imersos e da cÃlula de GrÃtzel. Para isso, alÃm de fazer vidros condutores à feito a deposiÃÃo da camada de diÃxido de titÃnio dopado com prata (TiO2:Ag), preparaÃÃo de eletrÃlito, preparaÃÃo de corante, montagem das cÃlulas e caracterizaÃÃo por voltagem de circuito aberto (Vca) e corrente de curto circuito (Icc). O vidro condutor possui um filme de diÃxido de estanho dopado com flÃor (SnO2:F). A deposiÃÃo do filme de SnO2:F sobre vidro à feito a temperatura de 600ÂC a parti de uma soluÃÃo precursora. Como fonte de calor usa-se uma resistÃncia cerÃmica conectada a um forno. Para a deposiÃÃo da soluÃÃo precursora à usado um gerador de âspray. As tÃcnicas difraÃÃo de raios x (DRX), microscopia de varredura eletrÃnica (MEV), UV-vis, resistÃncia elÃtrica e dureza de MÃhr sÃo usadas para caracterizar o vidro condutor e o eletrodo SnO2:F/TiO2:Ag. O vidro condutor apresenta transmitÃncia ~70% (650 nm - 800 nm). O eletrodo de SnO2:F/TiO2:Ag apresenta refletÃncia ~20%. As cÃlulas sob iluminaÃÃo sÃo caracterizadas por Vca e Icc. A cÃlula de GrÃtzel com corante extrato de espinafre apresenta Vca = 0,264 V e Icc = 1,4 μA, enquanto que a cÃlula de GrÃtzel com corante azul de metileno apresenta Voc = 0,186 V e Icc = 3,5 μA.
The conductor glasses have been used as transparent conductor oxides (TCOâs). Due to its transmittance in the visible spectrum and low sheet resistance, TCOâs have been employed as a constituent component of photoeletrochemical cells activated with dye. This work is dedicated to the conductor glass fabrication, at a lab scale, on 2,6 cm x 7,6 cm glass substrates by spray pyrolyris method and application of the conductor glasses in photoeletrochemical cells of the type GrÃtzel and immense electrode. The work involve the fabrication of the conductor glasses, deposition of the silver-doped titanium oxide (TiO2:Ag) films on conductor glasses, preparation of the electrolyte, choice and preparation of the dye and then to close and to characterize of the cells by open circuit voltage (Voc) and short circuit current (Icc). The conductor glass is of the type fluorine-doped tin oxide (SnO2:F). The deposition of SnO2:F layer is make on the glass substrate with temperature of 600ÂC from precursor solution. The heat source is ceramic heater of flat surface in a stove. The spray gun is used for to deposit the precursor solution on glass substrate. The conductor glasses and electrodes of SnO2:F/TiO2:Ag are characterized by measures of x-ray diffraction (XRD), scanning electron micrograph (SEM), UV-vis, electric resistance and MÃhr strong. The average transmittance of the conductor glass 70 % in the wavelength regions of 650 nm â 800 nm. The average reflectance of 20 % in the electrodes SnO2:F/TiO2:Ag with extract of spinach in the wavelength regions of 650 nm â 700 nm. In the characterization of the cells, measures of Voc and Icc are obtained for cells under illumination. To hotoeletrochemical cell of the type GrÃtzel with extract of spinach the measures are Voc = 0,264 V and Icc = 1,4 μA; while that for the photoeletrochemical cell of the type GrÃtzel with methylene blue the measures are Voc = 0,186 V and Icc = 3,5 μA.
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Silva, Erica Lira da. "Desenvolvimento de sistemas magn?ticos com potencialidades terap?uticas para vetoriza??o de f?rmacos." Universidade Federal do Rio Grande do Norte, 2010. http://repositorio.ufrn.br:8080/jspui/handle/123456789/13282.
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Magnetic targeting is being investigated as a means of local delivery of drugs, combining precision, minimal surgical intervention, and satisfactory concentration of the drug in the target region. In view of these advantages, it is a promising strategy for improving the pharmacological response. Magnetic particles are attracted by a magnetic field gradient, and drugs bound to them can be driven to their site of action by means of the selective application of magnetic field on the desired area. Helicobacter pylori is the commonest chronic bacterial infection. The treatment of choice has commonly been based upon a triple therapy combining two antibiotics and an anti-secretory agent. Furthermore, an extended-release profile is of utmost importance for these formulations. The aim of this work was to develop a magnetic system containing the antibiotic amoxicillin for oral magnetic drug targeting. First, magnetic particles were produced by coprecipitation of iron salts in alkaline medium. The second step was coating the particles and amoxicillin with Eudragit? S-100 by spray-drying technique. The system obtained demonstrated through the characterization studies carried out a possible oral drug delivery system, consisting in magnetite microparticles and amoxicillin, coated with a polymer acid resistant. This system can be used to deliver drugs to the stomach for treatment of infections in this organ. Another important finding in this work is that it opens new prospects to coat magnetic microparticles by the technique of spray-drying.
A vetoriza??o magn?tica tem sido investigada como uma forma de entrega local de f?rmacos combinando precis?o, m?nima interven??o cir?rgica e concentra??o satisfat?ria do f?rmaco na regi?o de interesse. Part?culas magn?ticas s?o atra?das a partir da aplica??o de um campo magn?tico e f?rmacos associados a essas part?culas podem ser direcionados ao seu s?tio de a??o atrav?s de uma aplica??o seletiva do campo na regi?o de interesse. Helicobacter pylori ? a mais comum causa de infec??o bacteriana cr?nica no est?mago. O tratamento padr?o ? a tripla terapia oral contendo dois antibi?ticos e um inibidor da bomba de pr?tons. Sendo assim, um perfil de libera??o prolongada ? de suma import?ncia para essas formula??es. O objetivo deste trabalho foi desenvolver um sistema magn?tico com potencial emprego na vetoriza??o de antibi?tico por via oral. Inicialmente, part?culas magn?ticas foram produzidas por co-precipita??o de sais de ferro em meio alcalino. Em seguida, as part?culas foram revestidas a partir da dispers?o da suspens?o magn?tica em uma solu??o contendo o pol?mero dissolvido e a amoxicilina, e ent?o submetido ? secagem por aspers?o (spray-drying). Atrav?s das caracteriza??es realizadas p?de-se verificar a obten??o de um potencial sistema para vetoriza??o de f?rmacos por via oral contendo micropart?culas de magnetita e amoxicilina revestidos por um pol?mero gastro-resistente. Adicionalmente, um importante aspecto nesse trabalho ? a abertura de novas perspectivas para o revestimento de micropart?culas magn?ticas atrav?s da t?cnica de spray-drying.
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Straeten, Thomas. "Optimierung des Sprengergebnisses mittels Spreng-Controlling /." Essen : VGE, Verl. Glückauf, 2006. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=014917796&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
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Pedro, Maria Angélica Marques [UNESP]. "Influência de encapsulantes e do método de secagem nas propriedades físico-químicas e atributos de qualidade de polpa de maracujá (Passifora edulis f. flavicarpa)." Universidade Estadual Paulista (UNESP), 2009. http://hdl.handle.net/11449/101967.
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pedro_mam_dr_sjrp.pdf: 1284122 bytes, checksum: 45709686cf62bab3c06f4aeffcf8c502 (MD5)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Os objetivos deste trabalho foram analisar a influência do tipo e da quantidade de aditivos, além de diferentes métodos de secagem da polpa de maracujá em pó, nas isotermas, propriedades termodinâmicas de sorção e nos atributos de qualidade do produto obtido. No capítulo 1 descreve-se o efeito de diferentes aditivos - maltodextrina DE 10 e goma arábica - sobre as isotermas de sorção nas temperaturas de 20, 30, 40 e 50 ºC de polpa de maracujá em pó obtida por secagem a vácuo. O modelo de GAB se ajustou aos dados de sorção. As isotermas apresentaram comportamento da curva do tipo II, na classificação de Brunauer. Observou-se que a adição de maltodextrina DE 10 e de goma arábica à polpa de maracujá desidratada reduziu a umidade de equilíbrio em relação à umidade da polpa pura e não houve diferença considerável entre as umidades de equilíbrio das amostras da polpa com 18% de goma arábica e polpa com 18% ou 55% de maltodextrina. O aumento da concentração da maltodextrina não teve influência sobre os valores de umidade de equilíbrio. O calor isostérico de sorção da polpa em pó aumentou com o decréscimo da umidade, ao mesmo tempo em que apresentou menores valores para a polpa em pó com aditivos do que os observados para a polpa pura. Através da teoria da compensação isocinética, pode-se concluir que o processo de sorção de água pela polpa de maracujá em pó é um processo espontâneo e controlado pela entalpia para todas as amostras testadas. No capítulo 2 foi analisada a influência de três métodos de secagem: em estufa a vácuo (60 ºC), spray drying (140 ºC) e liofilização sobre as isotermas da polpa de maracujá em pó com 55% de maltodextrina DE 10. O pó produzido em spray dryer apresentou maior capacidade de sorção em relação aos pós desidratados em estufa a vácuo e em liofilizador. No capítulo 3 foi avaliada a influência...
The objectives of this work were to analyze the influence of type and quantity of additives, in addition to different drying methods, on the production of powdered passion fruit pulp, on its water sorption isotherms and on its themodynamical properties, as well as evaluating the quality attributes of the obtained product. Chapter 1 describes the effect of different additives - maltodextrin DE 10 and Arabic gum - on the sorption isotherms at temperatures of 20, 30, 40 e 50 ºC of passion fruit pulp powder obtained by vacuum drying. The sorption data were well adjusted by GAB model. The isotherms presented behavior of type II curves according to the Brunauer classification. The addition of maltodextrin DE 10 and Arabic gum to the passion fruit pulp powder decreased the equilibrium water content when compared to the pure powdered pulp and no considerable differences between the equilibrium moisture content of samples with 18% of arabic gum and with 18% or 55% of maltodextrin were observed. The increase in maltodextrin concentration did not affect the equilibrium water contents. The isosteric heat of sorption of the powdered pulp increased with decreasing water content, at the same time that lower values were obtained to powdered pulp with additives than to pure powdered pulp. Through the isokinetic compensation theory it could be concluded that the water sorption process by the powdered passion fruit pulp is an enthalpy controlled, spontaneous process for all tested samples. In chapter II, the influence of three drying methods: vacuum drying (60 ºC), spray drying (140 ºC) and freeze drying over the powdered passion fruit pulp isotherms with 55% of maltodextrin DE 10, was analyzed. The passion fruit pulp powder produced by spray drying presented higher sorption ability than vacuum dried and freeze dried pulp. In chapter 3, the influence of different concentrations and different dextrose... (Complete abstract click electronic access below)
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Gartung, Kai. "Modellierung der Verdunstung realer Kraftstoffe zur Simulation der Gemischbildung bei Benzindirekteinspritzung /." Berlin : Logos Berlin, 2008. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=016700149&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
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Pedro, Maria Angélica Marques. "Influência de encapsulantes e do método de secagem nas propriedades físico-químicas e atributos de qualidade de polpa de maracujá (Passifora edulis f. flavicarpa) /." São José do Rio Preto : [s.n.], 2009. http://hdl.handle.net/11449/101967.
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Orientador: Vânia Regina Nicoletti TelisBanca: Caciano Pelayo Zapata Noreña
Banca: Joel Fernando Nicoleti
Banca: José Francisco Lopes Filho
Banca: José Antônio Gomes Vieira
Resumo: Os objetivos deste trabalho foram analisar a influência do tipo e da quantidade de aditivos, além de diferentes métodos de secagem da polpa de maracujá em pó, nas isotermas, propriedades termodinâmicas de sorção e nos atributos de qualidade do produto obtido. No capítulo 1 descreve-se o efeito de diferentes aditivos - maltodextrina DE 10 e goma arábica - sobre as isotermas de sorção nas temperaturas de 20, 30, 40 e 50 ºC de polpa de maracujá em pó obtida por secagem a vácuo. O modelo de GAB se ajustou aos dados de sorção. As isotermas apresentaram comportamento da curva do tipo II, na classificação de Brunauer. Observou-se que a adição de maltodextrina DE 10 e de goma arábica à polpa de maracujá desidratada reduziu a umidade de equilíbrio em relação à umidade da polpa pura e não houve diferença considerável entre as umidades de equilíbrio das amostras da polpa com 18% de goma arábica e polpa com 18% ou 55% de maltodextrina. O aumento da concentração da maltodextrina não teve influência sobre os valores de umidade de equilíbrio. O calor isostérico de sorção da polpa em pó aumentou com o decréscimo da umidade, ao mesmo tempo em que apresentou menores valores para a polpa em pó com aditivos do que os observados para a polpa pura. Através da teoria da compensação isocinética, pode-se concluir que o processo de sorção de água pela polpa de maracujá em pó é um processo espontâneo e controlado pela entalpia para todas as amostras testadas. No capítulo 2 foi analisada a influência de três métodos de secagem: em estufa a vácuo (60 ºC), spray drying (140 ºC) e liofilização sobre as isotermas da polpa de maracujá em pó com 55% de maltodextrina DE 10. O pó produzido em spray dryer apresentou maior capacidade de sorção em relação aos pós desidratados em estufa a vácuo e em liofilizador. No capítulo 3 foi avaliada a influência... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: The objectives of this work were to analyze the influence of type and quantity of additives, in addition to different drying methods, on the production of powdered passion fruit pulp, on its water sorption isotherms and on its themodynamical properties, as well as evaluating the quality attributes of the obtained product. Chapter 1 describes the effect of different additives - maltodextrin DE 10 and Arabic gum - on the sorption isotherms at temperatures of 20, 30, 40 e 50 ºC of passion fruit pulp powder obtained by vacuum drying. The sorption data were well adjusted by GAB model. The isotherms presented behavior of type II curves according to the Brunauer classification. The addition of maltodextrin DE 10 and Arabic gum to the passion fruit pulp powder decreased the equilibrium water content when compared to the pure powdered pulp and no considerable differences between the equilibrium moisture content of samples with 18% of arabic gum and with 18% or 55% of maltodextrin were observed. The increase in maltodextrin concentration did not affect the equilibrium water contents. The isosteric heat of sorption of the powdered pulp increased with decreasing water content, at the same time that lower values were obtained to powdered pulp with additives than to pure powdered pulp. Through the isokinetic compensation theory it could be concluded that the water sorption process by the powdered passion fruit pulp is an enthalpy controlled, spontaneous process for all tested samples. In chapter II, the influence of three drying methods: vacuum drying (60 ºC), spray drying (140 ºC) and freeze drying over the powdered passion fruit pulp isotherms with 55% of maltodextrin DE 10, was analyzed. The passion fruit pulp powder produced by spray drying presented higher sorption ability than vacuum dried and freeze dried pulp. In chapter 3, the influence of different concentrations and different dextrose... (Complete abstract click electronic access below)
Doutor
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Kurt, Osman. "Experimentelle Untersuchungen des Auftreffvorgangs von Sprays auf bewegter Zylinderoberfläche /." Düsseldorf : VDI-Verl, 2010. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=018910364&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
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Pontes, Thales Renan Ferreira. "Desenvolvimento de sistema magn?tico polim?rico contendo antimicrobianos para tratamento de infec??es por Helicobacter pylori." Universidade Federal do Rio Grande do Norte, 2014. http://repositorio.ufrn.br:8080/jspui/handle/123456789/18296.
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Helicobacter pylori is the main cause of gastritis, gastroduodenal ulcer disease and gastric cancer. The most recommended treatment for eradication of this bacteria often leads to side effects and patient poor compliance, which induce treatment failure. Magnetic drug targeting is a very efficient method that overcomes these drawbacks through association of the drug with a magnetic compound. Such approach may allow such systems to be placed slowed down to a specific target area by an external magnetic field. This work reports a study of the synthesis and characterization of polymeric magnetic particles loaded with the currently used antimicrobial agents for the treatment of Helicobacter pylori infections, aiming the production of magnetic drug delivery system by oral route. Optical microscopy, scanning electron microscopy, transmission electron microscopy, x-ray powder diffraction, nitrogen adsorption/desorption isotherms and vibrating sample magnetometry revealed that the magnetite particles, produced by the co-precipitation method, consisted of a large number of aggregated nanometer-size crystallites (about 6 nm), creating superparamagnetic micrometer with high magnetic susceptibility particles with an average diameter of 6.8 ? 0.2 μm. Also, the polymeric magnetic particles produced by spray drying had a core-shell structure based on magnetite microparticles, amoxicillin and clarithromycin and coated with Eudragit? S100. The system presented an average diameter of 14.2 ? 0.2 μm. The amount of magnetite present in the system may be tailored by suitably controlling the suspension used to feed the spray dryer. In the present work it was 2.9% (w/w). The magnetic system produced may prove to be very promising for eradication of Helicobacter pylori infections
A Helicobacter pylori ? a principal causa de gastrites, ?lceras gastroduodenais e c?ncer g?strico. O esquema terap?utico de primeira escolha para a erradica??o desse pat?geno leva muitas vezes a elevado n?mero de rea??es adversas, baixa ades?o do paciente e consequentemente falha na terap?utica. A vetoriza??o magn?tica ? uma t?cnica bastante difundida na literatura que visa minimizar esses problemas, atrav?s da associa??o de f?rmacos a n?cleos magn?ticos direcionando para o local de a??o por interm?dio de campo magn?tico externo. O presente trabalho relata o estudo da s?ntese e caracteriza??o de part?culas polim?ricas magn?ticas contendo os mais frequentes antimicrobianos (amoxicilina e claritromicina) usados no tratamento de infec??es por Helicobacter pylori, objetivando a produ??o de um sistema para vetoriza??o magn?tica por via oral. Granulometria baseada no di?metro de Feret, microscopia eletr?nica de varredura e transmiss?o, difratometria de raio-x, isotermas de adsor??o/dessor??o de nitrog?nio e magnetometria de amostra vibrante revelaram que as part?culas de magnetita, produzidas pelo m?todo da coprecipita??o, consistem em grande n?mero de agregados de cristalitos de tamanhos nanom?tricos (da ordem de 6 nm) os quais formam part?culas microm?tricas superparamagn?ticas de alta susceptibilidade magn?tica, tendo formato irregular com di?metro m?dio de 6,8 ? 0,2 μm. Os n?cleos magn?ticos foram revestidos por pol?mero (Eudragit? S100) em conjunto com amoxicilina e claritromicina (forma polim?rfica II) sendo obtido micropart?culas n?cleo-camada de formato irregular, pela t?cnica de secagem por aspers?o (spray dryer), com um di?metro m?dio de 14,2 ? 0,2 μm. A quantidade de magnetita presente no sistema pode ser adaptada pelo controle da suspens?o inicial usada na alimenta??o do spray dryer. No presente trabalho o conte?do magn?tico final foi estimado em 2,9 % (p/p). Com base nos resultados obtidos, o sistema magn?tico produzido pode se tornar bastante promissor na erradica??o de infec??es por Helicobacter pylori
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LIN, JUN-HUA, and 林俊華. "A simulation study of ionospheric spread F." Thesis, 1989. http://ndltd.ncl.edu.tw/handle/43180535008557524015.
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Yen, Chou Shueh, and 周雪燕. "Simulation of the neutral wind field effect on equatorial spread F." Thesis, 1995. http://ndltd.ncl.edu.tw/handle/64719132471309062349.
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博士國立中央大學
大氣物理研究所
84
The neutral wind field effects on the development of the equatorial plasma bubbles have been simulated by a two dimen- sional time-dependent model similar to that developed by Zal- esak and Ossakow. The results indicate that when there exists no neutral wind, any perturbation in the bottom-side of the ionosphere density profile will be amplified by Gravitational Rayleigh-Taylor instability and an up-welling bubble will form as expected. When a weak zonal neutral wind exists and as long as the bubble co-moves with the uniform wind,the bubbles will reserve its simple structure. As the neutral wind becomes str- onger, secondary structures called plumes will grow out from the side-walls of the primary bubble. If the neutral wind has strong vertical shear, east-west symmetry of plasma bubbles are strong- ly distorted. We notice that patches and multiple plumes struct- ures have been observed in the mid- and low- latitude ionosphere. So a two-dimensional linear theory of generalized GRT instabili- ty is present to explain the generation mechanism of the second- ary structures, and it is found that the secondary perturbation is especially unstable at the bubble''s leading edges, even when the bubble has already penetrated into topside ionosphere where linear GRT instability theory predicts stable.
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Chih-KaiChan and 詹智凱. "The Effect of Eliminating Form 20-F Reconciliation on Return Spread and Price Spread of US Cross-Listed Stocks." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/8cpctk.
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碩士國立成功大學
會計學系
102
This paper investigates the effect of change in accounting information environment on return spreads and price spreads between domestic stocks and their American Depository Receipts (ADRs) after U.S. Securities and Exchange Commission (SEC) announced that foreign issuers using international Financial Reporting Standard (IFRS) do not need to disclose the Form 20-F reconciliation. By using 65 U.S. cross-listed companies which use IFRS as their basis of financial reporting, I find that after eliminating the reconciliation from IFRS to US GAAP, the return spreads between domestic stocks and their ADRs do not become significantly larger. However, I find that the underlying share prices and the ADR prices diverge significantly after the elimination of 20-F reconciliation. The result implies that eliminating the reconciliation results in information loss or greater information asymmetry.
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Sinha, Saurabh. "A multi-dimensional spread spectrum transceiver." Thesis, 2008. http://hdl.handle.net/2263/28885.
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The research conducted for this thesis seeks to understand issues associated with integrating a direct spread spectrum system (DSSS) transceiver on to a single chip. Various types of sequences, such as Kasami sequences and Gold sequences, are available for use in typical spread spectrum systems. For this thesis, complex spreading sequences (CSS) are used for improved cross-correlation and autocorrelation properties that can be achieved by using such a sequence. While CSS and DSSS are well represented in the existing body of knowledge, and discrete bulky hardware solutions exist – an effort to jointly integrate CSS and DSSS on-chip was identified to be lacking. For this thesis, spread spectrum architecture was implemented focussing on sub-systems that are specific to CSS. This will be the main contribution for this thesis, but the contribution is further appended by various RF design challenges: highspeed requirements make RF circuits sensitive to the effects of parasitics, including parasitic inductance, passive component modelling, as well as signal integrity issues. The integration is first considered more ideally, using mathematical sub-systems, and then later implemented practically using complementary metal-oxide semiconductor (CMOS) technology. The integration involves mixed-signal and radio frequency (RF) design techniques – and final integration involves several specialized analogue sub-systems, such as a class F power amplifier (PA), a low-noise amplifier (LNA), and LC voltage-controlled oscillators (VCOs). The research also considers various issues related to on-chip inductors, and also considers an active inductor implementation as an option for the VCO. With such an inductor a better quality factor is achievable. While some conventional sub-system design techniques are deployed, several modifications are made to adapt a given sub-system to the design requirements for this thesis. The contribution of the research lies in the circuit level modifications done at sub-system level aimed towards eventual integration. For multiple-access communication systems, where a number of independent users are required to share a common channel, the transceiver proposed in this thesis, can contribute towards improved data rate or bit error rate. The design is completed for fabrication in a standard 0.35-μm CMOS process with minimal external components. With an active chip area of about 5 mm2, the simulated transmitter consumes about 250 mW&the receiver consumes about 200 mW. AFRIKAANS : Die navorsing wat vir hierdie tesis onderneem is, beoog om kundigheid op te bou aangaande die kwessies wat met die integrasie van ‘n direkte spreispektrumstelsel (DSSS) sender-ontvanger op ‘n enkele skyfie verband hou. Verskeie tipes sekwensies, soos byvoorbeeld Kasami- en Gold-sekwensies, is vir gebruik in tipiese spreispektrumstelsels beskikbaar. Vir hierdie tesis is komplekse spreisekwensies (KSS) gebruik vir verbeterde kruis- en outokorrelasie-eienskappe wat bereik kan word deur so ‘n sekwensie te gebruik. Alhoewel DSSS en KSS reeds welbekend is, en diskrete hardeware oplossings reeds bestaan, is die vraag na gesamentlike geïntegreerde DSSS en KSS op een vlokkie geïdentifiseer. Vir hierdie tesis is spreispektrumargitektuur aangewend met die klem op KSS substelsels. Dit is dan ook die belangrikste bydrae van hierdie tesis, maar die bydrae gaan verder gepaard met verskeie RF-ontwerpuitdagings: hoëspoed-vereistes maak RF-stroombane sensitief vir die uitwerking van parasitiese komponente, met inbegrip van parasitiese induktansie, passiewe komponentmodellering en ook seinintegriteitskwessies. Die integrasie word eerstens meer idealisties oorweeg deur wiskundige substelsels te gebruik en dan later prakties te implementeer deur komplementêre metaaloksied-halfgeleiertegnologie (CMOS) te gebruik. Die integrasie behels gemengdesein- en radiofrekwensie(RF)-ontwerptegnieke – en finale integrasie behels verskeie gespesialiseerde analoë substelsels soos ‘n klas F-kragversterker (KV), ‘n laeruis-versterker (LRV), en LC-spanningbeheerde ossileerders (SBO’s). Die navorsing oorweeg ook verskeie kwessies in verband met op-skyfie induktors en oorweeg ook ‘n aktiewe induktorimplementering as ‘n opsie vir die SBO. Met sodanige induktor is ‘n beter kwaliteitsfaktor haalbaar. Hoewel enkele konvensionele substelsel-ontwerptegnieke aangewend word, word daar verskeie wysigings aangebring om ‘n gegewe substelsel by die ontwerpvereistes vir hierdie tesis aan te pas. Die bydrae van die navorsing is hoofsaaklik die stroombaanmodifikasies wat gedoen is op substelselvlak om integrasie te vergemaklik. Vir veelvoudige-toegang kommunikasiestelsels waar ‘n aantal onafhanklike gebruikers dieselfde seinkanaal moet deel, kan die sender-ontvanger voorgestel in hierdie tesis meewerk om die datatempo en fouttempo te verbeter. Die ontwerp is voltooi vir vervaardiging in ‘n standaard 0.35-μm CMOS-proses met minimale eksterne komponente. Met ‘n aktiewe skyfie-oppervlakte van ongeveer 5 mm2, verbruik die gesimuleerde sender ongeveer 250 mW en die ontvanger verbruik ongeveer 200 mW.Thesis (PHD)--University of Pretoria, 2011.
Electrical, Electronic and Computer Engineering
unrestricted
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Paradza, Masimba Wellington. "Development of a neural network based model for predicting the occurrence of spread F within the Brazilian sector /." 2008. http://eprints.ru.ac.za/1621/.
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Peng, Bing-Cheng, and 彭秉正. "A comparion between Spread F and GPS phase fluctuation of 1996 and 2000 in Taiwan region." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/27596265806181085639.
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碩士國立中央大學
太空科學研究所
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There are many scientists have use many instruments to research the equatorial anomaly crest zone and analyze these data where they get. Because of the differentiation of instruments, the data get from them also have many differentiation. Therefore, using two kind of instruments to observe can provide detailed and overall views of this zone. It will introduce the calculation of phase fluctuation in this paper and compare different years' result.
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Zhao, Ying. "The influence of Yuan Sanqu on the formation and spread of Yuan Zaju." 2007. http://link.library.utoronto.ca/eir/EIRdetail.cfm?Resources__ID=788689&T=F.
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Hickey, Dustin A. "Spatial characteristics of the midnight temperature maximum and equatorial spread F from multi-instrument and magnetically conjugate observations." Thesis, 2018. https://hdl.handle.net/2144/33120.
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The upper atmosphere, a region above ~85 km called the ionosphere and thermosphere, has been studied extensively for over one hundred years. Measurements were often considered in isolation, but today, advances in technology and ground-based distributed arrays have allowed concurrent multi-instruments measurements. In this dissertation, I combine measurements from all-sky imagers (ASIs), coherent scatter radars, incoherent scatter radars (ISRs), and Fabry-Perot interferometers (FPIs). I focus on two phenomena, the midnight temperature maximum (MTM) and equatorial spread F (ESF), using observations from equatorial to mid-latitudes. The spatial characteristics of these phenomena are not fully understood. I combine observations at various latitudes and longitudes to extend MTM detection to mid-latitudes. I present the first simultaneous detections of the MTM at multiple altitudes and latitudes over North America and the first observations below the F-region peak using the Millstone Hill Observatory ISR in a south pointing, low-elevation mode. The MTM can also be observed with an ASI and I present concurrent measurements of the MTM with an ASI and ISR. The Whole Atmosphere Model, a global circulation model, was found to be consistent with these observations. This further verifies that the MTM is partially created by lower atmospheric tides, demonstrating coupling between the lower and upper atmosphere. In addition to the MTM, I investigate different aspects of ESF using ASIs concurrently with other instruments. I compare various scale sizes (sub-meter to kilometers) using coherent scatter radar and an ASI and conclude that the lower hybrid drift instability causes radar echoes to occur preferentially on the western wall of large-scale depletions. The source of day-to-day variability in ESF is not fully known but I show that one driver may be large-scale wave structures (~400 km) that modulate the development of ESF. Finally, I compare concurrent observations of ESF plasma depletions with ASIs at magnetically-conjugate foot points and show how the magnitude and structure of the Earth’s magnetic field is responsible for differences in the morphology and velocity of these depletions. In summary, I have used multi-instrument observations of ESF and the MTM to provide a deeper understanding of the dynamics of the upper atmosphere.
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Buberl, Thomas. "Kreditrisikobezogene Determinanten von Bond Spreads : eine empirische Untersuchung am US Bondmarkt /." 2002. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=009781264&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
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Gibbs, Jason. "Synapsis and meiotic nodules in the Lilium species-hybrid "Black Beauty" prepared using a novel plant chromosome spread technique for ultra-structural and immunocytochemical analyses." 2005. http://link.library.utoronto.ca/eir/EIRdetail.cfm?Resources__ID=362506&T=F.
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Bittner, Carsten. "Struktur und Qualität des deutschen Aktienmarkts : eine empirische Untersuchung des kontinuierlichen Handels in Xetra und an der Frankfurter Wertpapierbörse /." 2001. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=010042352&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
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Petersson, Isak. "Betydelsen av ett Nobelpris : Hur Boris Pasternaks Nobelpris i litteratur bidrog till att sprida hans författarskap." Thesis, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-24073.
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Denna studie undersöker och belyser sambanden mellan ryske författaren Boris Pasternaks erhållande av Nobelpriset i litteratur (1958) och spridningen av dennes författarskap. Syftet med studien är dels att definiera Nobelprisets roll som kulturspridare, men också att problematisera kulturprisers komplexa funktioner och inflytande över kulturell produktion. För att göra detta har två områden analyserats: Pasternaks utgivning på svenska samt dennes förekomst i svensk dagspress mellan 1953–2013. I analysen påvisas Nobelprisets starka konsekrerande effekt på ett författarskap såväl som prisets förmåga att på lång sikt kanonisera en författare. I enlighet med Englishs teori om hur kulturpriser verkar som medium för kapitalutbyte, framgår det också i analysen hur flera involverade intressenter kapitaliserat på Pasternaks pris genom att växla in kulturellt, ekonomiskt och medialt kapital. I analysen förtydligas dessutom hur kulturprisapparaten skapar och förstärker kulturellt värde, och hur dess inflytande därmed inte inskränker sig till den kulturella scenen utan också har möjligheten att påverka den allmänna politiska opinionen.This study explores and sheds light upon the relations between Russian author Boris Pasternak’s Nobel Prize in Literature (1958) and the subsequent proliferation of his authorship. The study’s aim is partly to define the Nobel Prize and its role as a distributor of culture, but also to problematize the complex nature of cultural prizes and their influence over cultural production. In order to do this two areas have been analysed: Pasternak’s publication in Swedish and his occurrence in Swedish daily press between 1953–2013. The analysis exemplifies the strong consecrating power of the Nobel prize, as well as its ability to, in a longer perspective, solidify an author into a literary canon. In line with English’s theory on how cultural prizes have come to serve as forums for capital intraconversion, it is also evident in Pasternak’s example how several of the involved parties have capitalized on the prize by trading cultural, economic and medial capital. Furthermore, the analysis concretizes how the cultural prize apparatus produces and reinforces cultural value, and consequently not only influences the cultural scene, but also has the potential to sway public political opinion.
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Shan, Yanguang. "A stochastic spray model for radio frequency inductively coupled plasmas." 2004. http://link.library.utoronto.ca/eir/EIRdetail.cfm?Resources__ID=80305&T=F.
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Jia, Libing. "Design and analysis of a low-temperature oxygen-fuel spray system." 2007. http://link.library.utoronto.ca/eir/EIRdetail.cfm?Resources__ID=742460&T=F.
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Xue, Minxia. "An extended numerical model for predicting the microstructure of thermal spray coatings." 2007. http://link.library.utoronto.ca/eir/EIRdetail.cfm?Resources__ID=478936&T=F.
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Wang, Youliang. "Deposition of solid oxide fuel cell electrodes by solution precursor plasma spray." 2008. http://link.library.utoronto.ca/eir/EIRdetail.cfm?Resources__ID=742609&T=F.
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Chien, L. Ken. "Solution precursor plasma spray deposition of porous tin oxide coatings for gas sensors." 2006. http://link.library.utoronto.ca/eir/EIRdetail.cfm?Resources__ID=442219&T=F.
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Mokrzycki, Paul. "The deposition of nanostructured yttria stabilized zirconia coatings via the solution precursor plasma spray process." 2005. http://link.library.utoronto.ca/eir/EIRdetail.cfm?Resources__ID=370385&T=F.
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Eslamian, Morteza. "Experimental and theoretical investigation of micro- and nano-powder synthesis by spray pyrolysis and drying." 2006. http://link.library.utoronto.ca/eir/EIRdetail.cfm?Resources__ID=449919&T=F.
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