Дисертації з теми "Internal density"
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Harris, Victoria Siân. "Creation of nonlinear density gradients for use in internal wave research." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/40437.
Повний текст джерела"June 2007."
Includes bibliographical references.
A method was developed to create a nonlinear density gradient in a tank of water. Such gradients are useful for studying internal waves, an ocean phenomenon that plays an important role in climate and ocean circulation. The method was developed by expanding on the two-tank system currently used to create linear density gradients. A mathematical model of the two-tank system was used and a Matlab script was written to solve the model for the required flow rates in the system given a desired density gradient. The method was tested by creating three different density gradients: a linear gradient, a hyperbolic gradient, and a two-layer gradient. It was discovered that for a two-layer gradient the flow rates for each layer must be calculated independently of each other, because of problems integrating over a density gradient with a non-continuous slope. It was also discovered that the system failed at very low flow rates; insufficient mixing in the two-tank system led to gradients weaker than expected. Overall, the measured gradients matched up well with the expected gradients, and it was concluded that the system can successfully produce nonlinear density gradients.
by Victoria Siân Harris.
S.B.
Westlake, P. C. "Interfacial and internal waves generated by a submerged prolate spheroid." Thesis, University of Southampton, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.242629.
Повний текст джерелаLee, Allison Marie. "An Experimental and Theoretical Investigation of Internal Wave Kinetic Energy Density in Variable Stratifications." BYU ScholarsArchive, 2019. https://scholarsarchive.byu.edu/etd/7737.
Повний текст джерелаKlaiber, Andreas [Verfasser]. "On the Spectral Stability of Internal Solitary Waves in Fluids with Density Stratification / Andreas Klaiber." Konstanz : Bibliothek der Universität Konstanz, 2013. http://d-nb.info/1045840556/34.
Повний текст джерелаHabib, Alexander J. "A Wireless Acquisition and Control System for a High Measurement-Density, Rotating Internal Heat Transfer Experiment." The Ohio State University, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=osu1397661589.
Повний текст джерелаYenket, Renoo. "Understanding methods for internal and external preference mapping and clustering in sensory analysis." Diss., Kansas State University, 2011. http://hdl.handle.net/2097/8770.
Повний текст джерелаDepartment of Human Nutrition
Edgar Chambers IV
Preference mapping is a method that provides product development directions for developers to see a whole picture of products, liking and relevant descriptors in a target market. Many statistical methods and commercial statistical software programs offering preference mapping analyses are available to researchers. Because of numerous available options, there are two questions addressed in this research that most scientists must answer before choosing a method of analysis: 1) are the different methods providing the same interpretation, co-ordinate values and object orientation; and 2) which method and program should be used with the data provided? This research used data from paint, milk and fragrance studies, representing complexity from lesser to higher. The techniques used are principal component analysis, multidimensional preference map (MDPREF), modified preference map (PREFMAP), canonical variate analysis, generalized procrustes analysis and partial least square regression utilizing statistical software programs of SAS, Unscrambler, Senstools and XLSTAT. Moreover, the homogeneousness of consumer data were investigated through hierarchical cluster analysis (McQuitty’s similarity analysis, median, single linkage, complete linkage, average linkage, and Ward’s method), partitional algorithm (k-means method), nonparametric method versus four manual clustering groups (strict, strict-liking-only, loose, loose-liking-only segments). The manual clusters were extracted according to the most frequently rated highest for best liked and least liked products on hedonic ratings. Furthermore, impacts of plotting preference maps for individual clusters were explored with and without the use of an overall mean liking vector. Results illustrated various statistical software programs were not similar in their oriented and co-ordinate values, even when using the same preference method. Also, if data were not highly homogenous, interpretation could be different. Most computer cluster analyses did not segment consumers relevant to their preferences and did not yield as homogenous clusters as manual clustering. The interpretation of preference maps created by the highest homogeneous clusters had little improvement when applied to complicated data. Researchers should look at key findings from univariate data in descriptive sensory studies to obtain accurate interpretations and suggestions from the maps, especially for external preference mapping. When researchers make recommendations based on an external map alone for complicated data, preference maps may be overused.
Clancy, Michael. "Application and development of high-density functional near infrared spectroscopy for traumatic brain injury." Thesis, University of Birmingham, 2017. http://etheses.bham.ac.uk//id/eprint/7758/.
Повний текст джерелаHashimoto, Kazuki. "Analysis and Design of Air-Core Transformer Based on Internal Magnetic Flux Density Distribution for High-Frequency Power Converter." Doctoral thesis, Kyoto University, 2021. http://hdl.handle.net/2433/263662.
Повний текст джерелаDilger, Erin. "The effects of host-vector relationships and density dependence on the epidemiology of visceral leishmaniasis." Thesis, University of Warwick, 2013. http://wrap.warwick.ac.uk/59680/.
Повний текст джерелаParida, Pritish Ranjan. "Optimization and Fabrication of Heat Exchangers for High-Density Power Control Unit Applications." Diss., Virginia Tech, 2010. http://hdl.handle.net/10919/77165.
Повний текст джерелаPh. D.
Chaichanawirote, Uraiwan. "Quality of Life of Older Adults: The Influence of Internal and External Factors." Case Western Reserve University School of Graduate Studies / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=case1301667819.
Повний текст джерелаConradie, Magda. "A comparative study of the determinants of bone strength and the propensity to falls in black and white South African women." Thesis, Stellenbosch : Stellenbosch University, 2008. http://hdl.handle.net/10019.1/1151.
Повний текст джерелаThe comparative study presented in this dissertation specifically aimed to assess fracture risk in black (Xhosa) and white South African women by evaluating known determinants of bone strength as well as the propensity to falls. We thus compared the prevalence of clinical (historic) risk factors for osteoporosis, measured and compared vertebral and femoral bone mineral density (BMD) employing dual energy X-ray absorptiometry (DEXA), ultrasound variables using the Sahara sonometer, serum parathyroid hormone (PTH) and 25-OH Vitamin D, mineral homeostasis and modern biochemical markers of bone turnover, bone geometry and the propensity to falls. Finally, we determined the prevalence of vertebral fractures in these black and white South African females. 1. Significant ethnic differences were noted in the presence and frequency of historical clinical and lifestyle risk factors for osteoporosis. Blacks were heavier and shorter, they consumed less calcium, were more inactive, preferred depot-medroxyprogesterone acetate as contraceptive agent and were of higher parity. Whites smoked more, preferred oral oestrogen containing contraceptive tablets and were more likely to have a positive family history of osteoporosis. Hormone therapy was used almost exclusively by postmenopausal whites. Inter-ethnic differences in weight, physical activity and high parity was most marked in the older subjects. 2. We found that peak spinal BMD was lower, but peak femoral BMD similar or higher (depending on the specific proximal femoral site measured) in black South-African females compared with whites. The lower peak spinal BMD was mainly attributed to lower BMD’s in the subgroup of black females with normal to low body weight, indicating that obesity either protected black females against a low spinal BMD or enhanced optimal attainment of bone mineral. An apparent slower rate of decline in both spinal- and femoral BMD with ageing was noted in the black females compared with whites in this cross-sectional study – an observation which will require confirmation in longitudinal, follow-up studies. This resulted in similar spinal BMD values in postmenopausal blacks and whites, but significantly higher femoral BMD measurements in blacks. The volumetric calculation of bone mineral apparent density (BMAD) at the lumbar spine and femoral neck yielded similar results to that of BMD. Spinal BMAD was similar in blacks and whites and femoral neck BMAD was consistently higher in all the menopausal subgroups studied. Weight significantly correlated with peak- and postmenopausal BMD at all sites in the black and white female cohorts. Greater and better maintained body weight may be partially responsible for slower rates of bone loss observed in black postmenopausal females. Most of the observed ethnic difference in BMD was, in fact, explained by differences in body weight between the two cohorts and not by ethnicity per se. 3. A low body weight and advanced age was identified as by far the most informative individual clinical risk factors for osteopenia in our black and white females, whereas physical inactivity was also identified as an important individual risk factor in blacks only. Risk assessment tools, developed and validated in Asian and European populations, demonstrated poor sensitivity for identification of South African women at increased risk of osteopenia. The osteoporosis risk assessment instrument (ORAI) showed the best results, with sensitivities to identify osteopenic whites at most skeletal sites approaching 80% (78% - 81%). The risk assessment tool scores appear to be inappropriate for our larger sized study cohort, especially our black subjects, thus resulting in incorrect risk stratification and poor test sensitivity. General discriminant analysis identified certain risk factor subsets for combined prediction of osteopenia in blacks and whites. These risk factor subsets were more sensitive to identify osteopenia in blacks at all skeletal sites, compared with the risk assessment tools described in the literature. 4. Higher ultrasonographically measured broadband ultrasound attenuation (BUA) and speed of sound (SOS) values were documented in our elderly blacks compared with whites, even after correction for differences in DEXA determined BMD at the spine and proximal femoral sites. BUA and SOS showed no decline with ageing in blacks, in contrast to an apparent significant deterioration in both parameters in ageing whites. If these quantitative ultrasound (QUS) parameters do measure qualitative properties of bone in our black population, independent of BMD as has been suggested in previous work in Caucasian populations, the higher values documented in elderly blacks imply better preservation of bone quality in ageing blacks compared with whites. The correlation between QUS calcaneal BMD and DEXA measured BMD at the hip and spine was modest at best. QUS calcaneal BMD was therefore unable to predict DEXA measured BMD at clinically important fracture sites in our study population. 5. Bone turnover, as assessed biochemically, was similar in the total pre- and postmenopausal black and white cohorts, but bone turnover rates appeared to differ with ageing between the two racial groups. A lower bone turnover rate was noted in blacks at the time of the menopausal transition and is consistent with the finding of a lower percentage bone loss at femoral sites at this time in blacks compared with whites. Bone turnover only increased in ageing postmenopausal blacks, and this could be ascribed, at least in part, to the observed negative calcium balance and the more pronounced secondary hyperparathyroidism noted in blacks. Deleterious effects of secondary hyperparathyroidism on bone mineral density at the proximal femoral sites were demonstrated in our postmenopausal blacks and contest the idea of an absolute skeletal resistance to the action of PTH in blacks. The increase in bone turnover and the presence of secondary hyperparathyroidism due to a negative calcium balance may thus potentially aggravate bone loss in ageing blacks, especially at proximal femoral sites. 6. Shorter, adult black women have a significantly shorter hip axis length (HAL) than whites. This geometric feature has been documented to protect against hip fracture. The approximately one standard deviation (SD) difference in HAL between our blacks and whites may therefore significantly contribute to the lower hip fracture rate previously reported in South African black females compared with whites. Average vertebral size was, however, smaller in black females and fail to explain the apparent lower vertebral fracture risk previously reported in this population. Racial differences in vertebral dimensions (height, width) and/or other qualitative bone properties as suggested by our QUS data may, however, account for different vertebral fracture rates in white and black women – that is, if such a difference in fact exists. 7. The number of women with a history of falls was similar in our black and white cohorts, and in both ethnic groups the risk of falling increased with age. There is a suggestion that the nature of falls in our black and white postmenopausal females may differ, but this will have to be confirmed in a larger study. Fallers in our postmenopausal study population were more likely to have osteoporosis than non-fallers. Postmenopausal blacks in our study demonstrated poorer outcomes regarding neuromuscular function, Vitamin D status and visual contrast testing and were shown to be more inactive with ageing compared with whites. An increased fall tendency amongst the black females could not however be documented in this small study. Quadriceps weakness and slower reaction time indicated an increased fall risk amongst whites, but were unable to distinguish black female fallers from non-fallers. 8. Vertebral fractures occurred in a similar percentage of postmenopausal blacks (11.5%) and whites (8.1%) in our study. Proximal femoral BMD best identified black and white vertebral fracture cases in this study. Quite a number of other risk factors i.e. physical inactivity, alcohol-intake, poorer physical performance test results and a longer HAL were more frequent in the white fracture cases and could therefore serve as markers of increased fracture risk, although not necessarily implicated in the pathophysiology of OP or falls. However, in blacks, only femoral BMD served as risk factor. Similar risk factors for blacks and whites cannot therefore be assumed and is deserving of further study. White fracture cases did not fall more despite lower 25-OH-Vitamin D, poorer physical performance and lower activity levels than non-fracture cases. Calcaneal ultrasonography and biochemical parameters of bone turnover were similar in fracture and non-fracture cases in both ethnic groups. Our study data on vertebral fractures in this cohort of urbanized blacks thus cautions against the belief that blacks are not at risk of sustaining vertebral compression fractures and emphasize the need for further studies to better define fracture prevalence in the different ethnic populations of South Africa. 9. In our study, hormone therapy in postmenopausal white women improved bone strength parameters and reduced fall risk. In hormone treated whites compared with non-hormone users, a higher BMD at the spine and proximal femur as determined by DEXA were documented and all QUS measurements were also significantly higher. The biochemically determined bone turnover rate, as reflected by serum osteocalcin levels, was lower in hormone users. Fall frequency was lower in the older hormone treated women (≥ 60yrs) and greater quadriceps strength and reduced lateral sway was noted. Only one patient amongst the hormone users (2%) had radiological evidence of vertebral fractures compared with four patients (6%) amongst the never-users. As hormone therapy was used almost exclusively by whites in this study population, the impact of hormone therapy on postmenopausal black study subjects could not be assessed.
Wang, Huan, and Huan Wang. "Flow Field Penetration in Thin Nanoporous Polymer Films under Laminar Flow by Förster Resonance Energy Transfer Coupled with Total Internal Reflectance Fluorescence Microscopy." Diss., The University of Arizona, 2015. http://hdl.handle.net/10150/565916.
Повний текст джерелаSánchez, Orgaz Eva María. "Advanced numerical techniques for the acoustic modelling of materials and noise control devices in the exhaust system of internal combustion engines." Doctoral thesis, Universitat Politècnica de València, 2016. http://hdl.handle.net/10251/64090.
Повний текст джерела[ES] Esta Tesis se centra en el desarrollo e implementación de métodos numéricos eficientes para el diseño y modelado de componentes de la línea de escape en motores de combustión interna. Merecen especial atención los silenciadores disipativos perforados de automóviles, ya que su comportamiento acústico puede sufrir variaciones importantes debidas a las variaciones de temperatura en el material absorbente, así como a las heterogeneidades de la fibra. Por tanto, se requieren técnicas numéricas que consideren estos casos para garantizar la precisión de los resultados. Se lleva a cabo una revisión bibliográfica que recoge los modelos de onda unidimensionales, así como modelos acústicos de materiales absorbentes y superficies perforadas. Sin embargo, las limitaciones de los primeros hacen indispensable el uso de modelos multidimensionales. Además se explora la posibilidad de usar nuevos elementos acústicos, cuyo objetivo es ser una alternativa potencial a los materiales absorbentes, que pueden tener un efecto negativo sobre la salud. La Tesis considera el uso de superficies microperforadas y sinterizadas. Estas últimas en algunos casos presentan una impedancia casi constante, cuyo valor depende, entre otras cosas, del espesor y la porosidad de las placas. Para evitar las limitaciones de los modelos de onda plana, se propone un enfoque en elementos finitos (EF) para el análisis acústico de silenciadores disipativos que incluyen un conducto con flujo medio axial uniforme y una cámara externa con una distribución heterogénea de material absorbente. Por otro lado, la variación de las propiedades también puede producirse por gradientes térmicos. En este caso, se propone una formulación híbrida de EF para silenciadores disipativos perforados que incluye: (1) Gradientes térmicos en el conducto central y la cámara; (2) Un conducto perforado que canaliza flujo medio axial no uniforme. Se ha implementado una formulación de EF para resolver la ecuación de ondas en términos de presión para el medio estacionario heterogéneo asociado a la cámara. Además, la ecuación asociada al conducto central, expresada en términos de potencial de velocidad acústica, permite la presencia de flujo axial no uniforme. El acoplamiento entre ambas regiones se ha realizado mediante un conducto perforado y su impedancia acústica y se ha adaptado para incluir la citada falta de homogeneidad. Se ha visto que las heterogeneidades pueden influir notablemente en la atenuación acústica de un silenciador, debiéndose incluir en los modelos teóricos. Las técnicas de optimización para componentes industriales de control de ruido son importantes, ya que producen elementos con mejores características. Los algoritmos evolutivos son técnicas emergentes capaces de obtener una solución, incluso cuando la optimización tradicional tiene dificultades. Las técnicas de optimización se combinan con el MEF para conseguir la máxima atenuación posible en el rango de frecuencias de interés. Se ha definido un problema de optimización de un silenciador multicámara y se han llevado a cabo varios análisis para obtener la configuración más adecuada para cada caso. Bajo ciertas hipótesis de uniformidad axial, se han considerado varias técnicas para reducir el coste computacional de un análisis 3D completo para silenciadores disipativos con gradientes de temperatura y flujo medio. Éstas se basan en la descomposición del campo acústico en modos axiales y transversales dentro de cada subdominio, y un procedimiento de acoplamiento de las expansiones modales en los cambios de sección del silenciador mediante las condiciones de continuidad de los campos acústicos. Se estudia la eficiencia computacional y precisión de las predicciones de las técnicas de acoplamiento, incluyendo colocación puntual en nodos y puntos de Gauss, así como ajuste modal. Todos ellos proporcionan predicciones precisas de la atenuación mejorando el coste
[CAT] Aquesta Tesi es centra en el desenvolupament i implementació de mètodes numèrics eficients per al disseny i modelatge de components de la línia d'escapament en motors de combustió interna. Mereixen especial atenció els silenciadors dissipatius perforats d'automòbils, ja que el seu comportament acústic pot patir variacions importants degudes a les variacions de temperatura en el material absorbent, així com a les heterogeneïtats de la fibra. Per tant, es requereixen tècniques numèriques que considerin aquests casos per garantir la precisió dels resultats. Es porta a terme una revisió bibliogràfica que recull els models d'ona unidimensionals, així com models acústics de materials absorbents i superfícies perforades. No obstant això, les limitacions dels primers fan indispensable l'ús de models multidimensionals. A més s'explora la possibilitat d'usar nous elements acústics amb l'objectiu que siguen una alternativa potencial als materials absorbents, que poden tenir un efecte negatiu sobre la salut. La Tesi considera l'ús de superfícies microperforades i sinteritzades. Aquestes últimes en alguns casos presenten una impedància gairebé constant. El seu valor depèn, entre altres coses, del gruix i la porositat de les plaques. Per evitar les limitacions dels models d'ona plana, es proposa un enfocament amb elements finits (EF) per a l'anàlisi acústic de silenciadors dissipatius que inclouen un conducte amb flux mig axial uniforme i una càmera externa amb una distribució heterogènia de material absorbent. D'altra banda, la variació de les propietats també es pot produir per gradients tèrmics. En aquest cas, es proposa una formulació híbrida d'EF per silenciadors dissipatius perforats que inclou: (1) Gradients tèrmics en el conducte central i la càmera; (2) Un conducte perforat que canalitza flux mig axial no uniforme. S'ha implementat una formulació d'EF per resoldre l'equació d'ones en termes de pressió per al medi estacionari heterogeni associat a la càmera. A més, l'equació associada al conducte central, expressada en termes de potencial de velocitat acústica, permet la presència de flux axial no uniforme. L'acoblament entre les dues regions s'ha realitzat mitjançant un conducte perforat i la seva impedància acústica i s'ha adaptat per incloure la esmentada falta d'homogeneïtat. S'ha vist que les heterogeneïtats poden influir notablement en l'atenuació acústica d'un silenciador i s'han d'incloure en els models teòrics. Les tècniques d'optimització per a components industrials de control de soroll són importants, ja que produeixen elements amb millors característiques. Els algoritmes evolutius són tècniques emergents capaces d'obtenir una solució, fins i tot quan l'optimització tradicional té dificultats. Les tècniques d'optimització es combinen amb el mètode d'elements finits (MEF) per aconseguir la màxima atenuació possible en el rang de freqüències d'interès. S'ha definit un problema d'optimització d'un silenciador multicàmera i s'han dut a terme diverses anàlisis per obtenir la configuració més adequada per a cada cas. Sota certes hipòtesis d'uniformitat axial, s'han considerat diverses tècniques per reduir el cost computacional d'una anàlisi 3D complet per silenciadors dissipatius amb gradients de temperatura i flux mig. Aquestes es basen en la descomposició del camp acústic en modes axials i transversals dins de cada subdomini, i un procediment d'acoblament de les expansions modals en els canvis de secció del silenciador mitjançant les condicions de continuïtat dels camps acústics. S'estudia l'eficiència computacional i precisió de les prediccions de les tècniques d'acoblament, incloent col·locació puntual en nodes i punts de Gauss, així com ajust modal. Tots ells proporcionen prediccions precises de l'atenuació millorant el cost computacional d'EF.
Sánchez Orgaz, EM. (2016). Advanced numerical techniques for the acoustic modelling of materials and noise control devices in the exhaust system of internal combustion engines [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/64090
TESIS
Johnston, Nina. "Low-Density Lipoprotein Oxidation and Renal Dysfunction : New Markers of Poor Prognosis in Patients with Unstable Coronary Artery Disease." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-6626.
Повний текст джерелаShavitranuruk, K. "Long Cavity Quantum Dot Laser Diode and Monolithic Passively Mode-Locked Operation." Doctoral diss., University of Central Florida, 2010. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3392.
Повний текст джерелаPh.D.
Optics and Photonics
Optics and Photonics
Optics PhD
Krishnakanth, Pushpanjali. "Mechanical considerations in fracture fixation." Thesis, Queensland University of Technology, 2012. https://eprints.qut.edu.au/51002/1/Pushpanjali_Krishnakanth_Thesis.pdf.
Повний текст джерелаHill, Esme. "Perfusion imaging and tissue biomarkers for colorectal cancer." Thesis, University of Oxford, 2015. https://ora.ox.ac.uk/objects/uuid:4a309265-6f27-4839-9259-f19cf9648c2d.
Повний текст джерелаPinaud, Johan. "Etude expérimentale d'anneaux tourbillonnaires impactant une stratification : dynamique tourbillonnaire et génération d'ondes internes." Thesis, Toulouse 3, 2020. http://www.theses.fr/2020TOU30271.
Повний текст джерелаIn this work, the interaction between model vortex structures observed in many flows, vortex rings, and a linearly stratified fluid is studied. A light homogeneous vortex ring is generated and penetrates by inertia into a density stratification. The resulting interaction depends on several control parameters which are: the dimensions of the vortex ring, its propagating speed, its orientation relative to the vertical, its initial density and the density gradient of the stratification. For short times, baroclinic vorticity is generated as the vortex ring pushes isopycnal during the penetration phase. The vortex ring dynamics is highly affected by its interaction with the stratified zone leading to reorganisation of the vorticity distribution depending on the control parameters. For long times, internal gravity waves are generated as the stratification relaxes. Several key points are adressed throughout the chapters. What is the maximum penetration depth a vortex ring can reach? What is the mechanism for the vortex ring recoil? What are the time scales of the vorticity reorganisation and generation of internal waves? What are the characteristics of the internal waves generated by the impact of such a localized fluid structure and how to quantify them? What is the influence of the angle of propagation of the vortex ring on the reorganisation of the flow? How is the flow modified when two vortex rings are launched consecutively? What is the role of the time delay between the generation of the vortex rings on the penetration depth reached and the internal waves generated? Qualitative (visualizations) and quantitative (2D-Particles Image Velocimetry and 4D-Particle Tracking Velocimetry) have been deployed to answer these questions
Nordström, Anna. "Bone mass and physical activity." Doctoral thesis, Umeå universitet, Medicin, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-224.
Повний текст джерелаJuhoor, Karim Khan. "Étude et modélisation d’écoulements en convection mixte : application au désenfumage naturel de bâtiments." Thesis, La Réunion, 2018. http://www.theses.fr/2018LARE0027/document.
Повний текст джерелаThis thesis work presents deals with the issue of fire safety consideration in naturally ventilated buildings. The particular case of the interaction between the wind and hot smoke movement is pinpointed. In the first chapter, basics of natural ventilation mechanisms are shown. Then, the analysis of building’s regulations, relating to fire safety and thermal comfort, allows to highlight potential conflicts and normative gaps. Theses gaps and conflicts are illustrated through real buildings feedbacks. The challenge of indoor flow pattern studies for safety purpose is hence underline. In the second chapter, scientific’s barriers in relation with the transitions between existing flow pattern, when wind and buoyancy are opposed, are identified thought a literature review. A scaled experiment is proposed in the third chapter, using density difference between air and helium, to identify internal flow pattern when wind opposes buoyancy. Three stable internal flow patterns are identified. A power law characterizing the transitions between identified flow pattern, involving source Froude number and dynamic pressure ratio between source jet and wind, is found. In the fourth chapter, the identified flow pattern are observed when the tested volume is emptied, and a relation between the initial Richardson number Ri and the characteristic emptied time θ is found. Furthermore, specific behaviour of internal flow, when the volume is emptied, is quantitatively study thanks to a numerical model. In the last part of this thesis, transitions law between internal flow patterns allows to introduce a new wind dependent fire safety index. A methodology is then proposed to both analyse fire safety and thermal comfort in building. The presented method gives the opportunity to avoid conception conflicts underlined in the first chapter of the present work
Mattsson, Göran. "Experimental Studies on the Vasculature of Endogenous and Transplanted Islets of Langerhans." Doctoral thesis, Uppsala University, Department of Medical Cell Biology, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-3596.
Повний текст джерелаThe blood vessels of the pancreatic islets are of crucial importance for oxygen and metabolite supply as well as dispersal of secreted hormones. In addition to this, endothelial cells have an important role in the revascularization process after islet transplantation. Previous studies have reported signs of poor engraftment of transplanted islets, presumably due to impaired revascularization. The aims of this thesis were to investigate the revascularization process of transplanted islets and to examine the role of islet endothelial cells. In this context, the lectin Bandeiraea simplicifolia was found to stain endothelium of both endogenous and transplanted pancreatic islets. By using this lectin we investigated the vascular density of both endogenous and islets transplanted syngeneically beneath the renal capsule, into the spleen or intraportally into the liver of normoglycemic C57BL/6 mice. One month post-transplantation, a time point when the grafts are assumed to be completely revascularized, the vascular density was decreased at all three implantation sites when compared to endogenous islets. Furthermore, most of the blood vessels were located in the graft connective tissue stroma. Similar results were obtained when islet transplant vascular density was determined six months post-transplantation and in cured diabetic animals after one month. In order to evaluate the function of intraportally transplanted islets, we developed a method to retrieve such islets. We treated the implantation organ (liver) first enzymatically (collagenase) and then mechanically, thereafter we could re-isolate the transplanted islets for further in vitro studies. The retrieved islets had a decreased insulin relase, insulin content and glucose oxidation rate when compared to non-transplanted control islets. To understand the role of islet endothelium in the revascularization of transplanted islets we performed angiogenesis GEArray studies on islet endothelial cells, from non-cultured, cultured and transplanted islets. We found that the islet endothelium expressed mRNA for both inhibitors and inducers of angiogenesis, and that this expression differed with time. The functional consequences of this remain to be determined. In summary, the results presented above provide a useful platform for future studies of the morphology and function of islet endothelial cells, especially with a view for elucidating changes induced by islet transplantation.
Galzin, Fabienne. "Contribution à la modélisation de la combustion dans les moteurs a allumage commandé." Rouen, 1996. http://www.theses.fr/1996ROUES064.
Повний текст джерелаTehranchi, Babak 1968. "Time-interval quantization in a high-density optical data storage system." Thesis, The University of Arizona, 1992. http://hdl.handle.net/10150/278151.
Повний текст джерелаWågsäter, Dick. "CXCL16 and CD137 in Atherosclerosis." Doctoral thesis, Örebro University, Institutionen för vårdvetenskap och omsorg, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-115.
Повний текст джерелаAtherosclerosis is a progressive inflammatory disease that is characterized by the accumulation of lipids, infiltrated cells and fibrous elements in large arteries.
This thesis focuses on the molecular mechanisms behind foam cell formation and inflammation, two central processes in the development of atherosclerosis. More specific, we studied the effects of proinflammatory cytokines on CXCL16 expression and its role as scavenger receptor on macrophages and smooth muscle cells in atherogenesis. CXCL16 is defined as a chemokine and a scavenger receptor, regulating adhesion and chemoattraction of CXCR6 expressing cells and uptake of oxLDL. We show that the expression of CXCL16 and its receptor CXCR6 are more pronounced in human atherosclerotic lesions compared with non-atherosclerotic vessels. Increased expression of CXCL16 was also seen in atherosclerotic aortas of apoE-/- mice compared with aortas of non-atherosclerotic, age-matched C57BL/6 mice. In vitro, IFN gamma induced CXCL16 expression in primary human monocytes and smooth muscle cells which resulted in an increased uptake of oxLDL. Treatment of mice with IFN gamma also induced CXCL16 expression in atherosclerotic lesions. Thus, we have demonstrated a role for IFN gamma in foam cell formation through upregulation of CXCL16. The expression of CXCR6 was defined to the same regions as for CXCL16 in the lesion, indicating the presence of cells able to respond to CXCL16. Consequently, CXCL16 could serve as a molecular link between lipid metabolism and immune activity in atherosclerotic lesion.
CD137 belongs to the TNF family and mediates several important processes in inflammation. CD137 is involved in the activation of T cells, NK cells, B cells and monocytes and regulate cytokine production, proliferation and apoptosis in these cells. A limited number of studies have demonstrated CD137 expression on smooth muscle cells and endothelial cells. Our results show that CD137 mRNA is higher expressed in human atherosclerotic lesions compared with unaffected vessels. We found that endothelial cells express CD137 in atherosclerotic lesions and that cultured endothelial cells and smooth muscle cells express CD137 and CD137 ligand in vitro. CD137 was regulated differentially by proinflammatory cytokines (i.e. IFN gamma, TNF alpha, IL-1 beta) and bacterial lipopolysaccharide depending on cell type. Furthermore, we investigated the effects of CD137 signalling, demonstrating that binding of the CD137 ligand to its receptor increases proliferation and migration of smooth muscle cells.
In summary, this thesis has focused on the expression, regulation and role of CXCL16 and CD137, two genes that have not been described earlier in the concept of atherosclerosis. The findings demonstrate some of the molecular mechanisms involved in vascular inflammation and may increase our knowledge about the development of atherosclerosis.
Chen, Hongjiang. "Studies on Cell Injury Induced by Hypoxia-Reoxygenation and Oxidized Low Density Lipoprotein : With Special Reference to the Protectiove Effect of Mixed Tocopherols, Omega-3 Fatty Acids and Transforming Growth Factor-beta1." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-3769.
Повний текст джерелаGislén, Mikael. "Achieving Agile Quality : An Action Research Study." Thesis, Blekinge Tekniska Högskola, Institutionen för kreativa teknologier, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-13732.
Повний текст джерелаFruchard, Nicolas. "L'allumage dans les moteurs à essence. Une modélisation et des applications." Rouen, 1995. http://www.theses.fr/1995ROUES053.
Повний текст джерелаDeng, Qingming. "Computational analysis of electronic properties and mechanism of formation of endohedral fullerenes and graphene with Fe atoms." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-203016.
Повний текст джерелаRAMIREZ, CAROLINE. "Contribution à l'étude des ondes internes non-linéaires en milieu tournant." Université Joseph Fourier (Grenoble), 1997. http://www.theses.fr/1997GRE10221.
Повний текст джерелаŠalplachta, Jakub. "Analýza 3D CT obrazových dat se zaměřením na detekci a klasifikaci specifických struktur tkání." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2017. http://www.nusl.cz/ntk/nusl-316836.
Повний текст джерелаIngberg, Claes-Mårten. "Type 1 diabetes mellitus: Aspects of long-term complications and body composition." Doctoral thesis, Uppsala University, Department of Medical Sciences, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-3287.
Повний текст джерелаStudies concerning social consequences, gastrointestinal and urinary tract symptoms were conducted in a population-based cohort comprising patients with long-standing type 1 diabetes and matched control persons. Three different questionnaires were sent by mail to diabetic patients and control persons. After a mean duration of 28.7±2.6 years, compared to the controls the diabetic patients showed an almost 10 times higher mortality, a lower employment rate and greater need for welfare benefits. These differences were mainly due to diabetic late complications. Education, housing conditions, life-style, civil state, alcohol and smoking habits were similar in the two groups. The prevalence of gastrointestinal symptoms was significantly higher in the diabetic patients than in the controls, and this was found to be attributable to the female diabetic patients. Female diabetic patients had been treated with antibiotics for urinary tract infections more often than controls, they experienced more social problems than controls in daily life because of urinary tract problems and used clamps to prevent wetting more often than did controls.
Body composition and bone mineral density were evaluated in parts of the cohort with long-standing type 1 diabetes and control persons in another population-based cohort comprising diabetic females aged 16-19 years with type 1 diabetes since childhood and matched controls. Besides a tendency to reduced abdominal fat mass in diabetic males, no difference was observed in fat mass, muscle mass or bone mineral density between the patients with long-standing type 1 diabetes and controls. Significant correlations were found between insulin dosage and whole body fat mass in diabetic females and between serum cholesterol levels and abdominal fat mass in diabetic males. The female adolescents had a higher body mass index than the controls, and their overweight was shown to consist almost entirely of an increased fat mass. The distribution of fat, expressed as abdominal-to-leg ratio, correlated significantly to HbA1c and daily dosage of insulin. Bone mineral density did not differ between the groups. IGF I was significantly lower both in patients with long-standing type 1 diabetes and in the adolescent diabetic females compared with their matched controls.
Mantel, Thierry. "Contribution à la modélisation de la combustion dans les moteurs à allumage commandé avec prise en compte de la phase d'allumage." Rouen, 1993. http://www.theses.fr/1993ROUES010.
Повний текст джерелаBarceló, Lladó Marc. "Wireless sensor networks in the future internet of things: density, mobility, heterogeneity and integration." Doctoral thesis, Universitat Autònoma de Barcelona, 2015. http://hdl.handle.net/10803/319688.
Повний текст джерелаWireless sensor networks (WSNs) are expected to revolutionize the way we live, work, and interact with the physical environment. Although WSNs have been in the spotlight of the research community for the last decade, their performance in practical implementations is still far behind the theoretical results. This is mainly due to the practical issues that arise in real-life scenarios. As a result, WSNs are generally limited to simple environmental sensing applications. The aim of this thesis is to reduce the gap between the theoretical and real potential of WSNs, and therefore increase their integration in society. In particular, this thesis focuses on the following four practical obstacles: high node density, node mobility, traffic heterogeneity and integration with the future Internet of Things (IoT). First, we deal with the interference problem in high density sensor deployments. We address this issue proposing a pragmatic joint routing, transmission power control and channel allocation approach, built upon the well-known RPL (Routing Protocol for Low-Power and Lossy Networks). This reduces the average packet collisions and the energy consumption of WSNs. Second, we address the low communication reliability and robustness in WSNs with mobile nodes. In particular, we propose a solution that combines RPL with a position-based routing approach based on Kalman filtering. This provides the efficiency and reliability of RPL, and also includes mobility support for non-static nodes. Third, we study the problem of QoS (Quality of Service) provisioning in WSNs managing heterogeneous traffic. With this in mind, we propose a multi-tree approach based on the construction of multiple RPL Instances. This constructs multiple virtual topologies to address the particular requirements of each traffic flow individually. Finally, we focus on the efficient integration of wireless sensors with Cloud-based IoT platforms. In particular, we propose a formulation to orchestrate the resource utilization of the whole network, taking advantage of the recent advances in virtualization and mobile cloud computing. This optimizes the overall consumption, considering the capabilities and limitations of each node, while satisfying the service requirements and the individual users' demands.
Ruffato, Daniel Giancolli. "Circulação na Plataforma Continental Interna e Média do Estado de São Paulo durante o verão: estudos numéricos." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/21/21132/tde-19042012-152414/.
Повний текст джерелаThe aim of this study was simulate the hydrodynamic of the Inner Continental Shelf of the State of São Paulo (PCISP) and of the Mid Continental Shelf of the State of São Paulo (PCMSP) during summer, in response to the density gradient forcing, to the climatological wind shear stress forcing and to the tide forcing, applying the tridimensional hydrodynamic numeric model Regional Ocean Modeling System (ROMS). The experiments performed showed the effects of the density distribution over the general circulation behavior in the PCISP and PCMSP are secondary compared with the induced climatological wind shear stress circulation. The results indicate that in the PCISP and in the PCMSP the component velocity parallel to the coast is dominated by subinertial frequencies forcing, as the climatological wind and the density gradient, while the component velocity perpendicular to the coast is strongly influenced by the tide forcing.
Arruda, Tiago José. "Energia interna e espalhamento de ondas eletromagnéticas por esferas ou clilindros: ressonâncias de Fano e suas aplicações a metamateriais." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/59/59135/tde-05022015-172627/.
Повний текст джерелаElectromagnetic wave scattering by single particles with both shapes and optical properties arbitrary finds applications in several areas of knowledge. Usually, the electromagnetic scattering is investigated via measured quantities in the far-field region. However, for inhomogeneous particles, resonances in scattering cross sections may not correspond to the electromagnetic field enhancement in the vicinity of a particle (near-field). This effect can be induced in dielectric nanoparticles with plasmonic coatings, and it has recently been explained in terms of the Fano resonance. The Fano resonance results from the interference between a non-resonant electromagnetic mode (background or continuous) and a resonant discrete mode (localized plasmon resonance), leading to an asymmetric lineshape. To understand how the surface modes in the near-field are connected to the cross section resonances, functionals of the electromagnetic fields within scatterers or in their vicinity are required. In this study, we calculate the electromagnetic energy inside scatterers in both cylindrical and spherical geometries. We obtain a connection between the internal energy and the scattering quantities in the far-field via absorption cross section and energy conservation. We apply our results to dispersive metamaterials, studying scattering properties of coated and chiral spheres in the negative refraction regime, and coated cylinders under oblique incidence of radiation. By the electromagnetic energy inside particles, we demonstrate new off-resonance field enhancement effects and provide analytical tools to analyze these resonances in both single and multiple scattering regimes.
Gomà, Llairo Eduard. "Exploiting wireless local area network density to improve energy and bandwidth allocation in internet access networks." Doctoral thesis, Universitat Pompeu Fabra, 2014. http://hdl.handle.net/10803/145501.
Повний текст джерелаEl uso de Internet en entornos residenciales no es constante. Los usuarios combinan períodos de desconexión con otros de bajo uso y algunos de alta actividad. Aún así, las redes de acceso a Internet proporcionan una máxima velocidad constante con un consumo energético también constante. La diferencia entre el uso de las redes y su consumo resulta en un desperdicio energético. Además, las velocidades máximas obtenidas por los usuarios son insuficientes para satisfacer sus picos de demanda. La baja utilización media de las redes de acceso – inferior al 10%— pone en evidencia este desperdicio. Mientras tanto, las cifras de consumo energético de las principales operadoras de telecomunicaciones son impresionantes y la velocidad máxima de conexión en muchas regiones del mundo sigue siendo insuficiente para ofrecer servicios como la transmisión de video en alta definición. En esta disertación propongo aprovechar la alta densidad de redes inalámbricas existente en entornos urbanos para reducir el desperdicio de energía de las redes de acceso e incrementar la máxima velocidad de conexión a Internet. Esta densidad permite i) agrupar usuarios con un bajo consumo de Internet en un subgrupo de líneas de acceso y apagar las que queden sin usar, y ii) agrupar la capacidad de varias líneas de acceso para aumentar la velocidad de conexión de los usuarios que lo necesiten. Los resultados presentados en esta disertación muestran que i) combinando la reducción de líneas activas con simples conmutadores en las centrales de los operadores se puede reducir el consumo energético de las redes de acceso en un 66% y ii) los usuarios pueden experimentar un aumento de su velocidad de hasta 4 veces. Esta tesis doctoral ha despertado gran inter ́es en las principales operado- ras de Internet. De hecho, Telefónica ha decidido comercializar las ideas presentadas en esta disertación y está realizando pruebas comerciales en España.
Romero, Euriel Millán. "Condutividade hidráulica, porosidade e resistência à penetração em Latossolos artificialmente compactados." Universidade Federal de Viçosa, 2007. http://locus.ufv.br/handle/123456789/5510.
Повний текст джерелаThe understanding and quantification of the impact of use and management of soil in its physical quality, in relation to prevention of compaction, are fundamentals in the development of sustainable agricultural systems. The objective of this work was performed with sample of a clayey Red Latosol and clayey Red Yellow Latosol, estimating hydraulic conductivity in saturated medium, macro and micro porosity in response to the index of compaction (IC) defined by the relation between the bulk density and the maximum density determined by test of Proctor. Also quantify the resistance of penetration, in response to IC and water potential of the soil and calculate the optimum hydric interval (OHI) seeking its utilization as indicator of physical quality of the soil. The OHI is an area limited by four dependent variables related to bulk density such as: aeration porosity, water content determined on volumetric bases -100 hPa and -15.000 hPa and the water content on volumetric bases permitting to maintain the resistance of the penetration in a pre-fixed value. The experimental unit were cylinders of soil artificially compacted to attained IC with in interval of 0.70 to 1.00. The resistance of the penetration was determined, additionally, in the interval limited by extreme potentials of -60 and -15.000 hPa. The results of the experiment permitted to conclude that: a) the hydraulic conductivity and macro porosity were reduced with the increment of IC and the increment of micro porosity is lower than the reduction of macro porosity in response to the compaction; b) the resistance of penetration increases with the increment of the compaction. It also increases with water potential of the soil decreases. The LVA with high water content in the working potential, reached to lower values of resistance of penetration and the difference is less accentuated, in response to the potential, as that of the LV; c) the determination of OHI is important to decrease the loss of productivity due to compaction, to establish limit of restriction in aeration of root system and the resistance of soil in the growth of roots; d) the convergence of results is indicator of the importance of using relative values, such as IC, in the comparison of soil characteristics, since the absolute value showed high divergence; e) IC in the range of 0.70 to 0.85 did not give restriction in the growth of the plants. High values indicated, initially restriction in the aeration of soil and when the range of 0.95 to 1.00, ending root growth due to resistance of penetration.
A compreensão e a quantificação do impacto do uso e manejo do solo na sua qualidade física, como a prevenção da compactação, são fundamentais no desenvolvimento de sistemas agrícolas sustentáveis. Foram objetivos deste trabalho, realizado com amostras de um Latossolo Vermelho argiloso e um Latossolo Vermelho Amarelo muito argiloso, quantificar a condutividade hidráulica em meio saturado, a macro e a microporosidade em resposta ao índice de compactação (IC), definido pela relação entre a densidade do solo e a densidade máxima determinada pelo ensaio de Proctor. Também quantificar a resistência à penetração, em resposta ao IC e ao potencial da água do solo, e calcular o intervalo hídrico ótimo (IHO), visando sua utilização como indicador da qualidade física do solo. O IHO é uma área delimitada por relações de quatro variáveis dependentes com a densidade do solo: porosidade de aeração, conteúdo de água base volumétrica determinada a -100 hPa e a -15.000 hPa e conteúdo de água base volumétrica que permite manter a resistência à penetração num valor prefixado i. As unidades experimentais foram cilindros de solo artificialmente compactados para atingir IC no intervalo de 0,70 a 1,00. A resistência à penetração foi determinada, adicionalmente, no intervalo delimitado pelos potenciais extremos de -60 e -15.000 hPa. Os resultados experimentais permitiram concluir que: a condutividade hidráulica e a macroporosidade são reduzidas com o incremento do IC e o incremento da microporosidade é inferior à diminuição da macroporosidade em resposta à compactação; a resistência à penetração aumenta com o incremento da compactação e a diminuição do potencial da água do solo. O LVA, com maior conteúdo de água nos potenciais de trabalho, apresentou menores valores de resistência à penetração e diferenças menos acentuadas, em resposta ao potencial, que o LV; a determinação do IHO é complemento adequado para diminuir perdas de produtividade em resposta à compactação, por estabelecer limites de restrição à aeração do sistema radicular e de resistência do solo ao crescimento das raízes; a convergência de resultados é indicativa da importância do uso de valores relativos, como o IC, na comparação de características de solos, em que os valores absolutos apresentam acentuada divergência; o IC na faixa de 0,70 a 0,85 não oferece restrições ao crescimento das plantas. Valores superiores indicam, inicialmente, restrições à aeração do solo e, quando na faixa de 0,95 a 1,00, impedimento ao crescimento de raízes pela resistência à penetração.
Ahmed, Aqeel. "LES of atomization and cavitation for fuel injectors." Thesis, Normandie, 2019. http://www.theses.fr/2019NORMR048/document.
Повний текст джерелаThis thesis presents Large Eddy Simulation (LES) of fuel injection, atomization and cavitation inside the fuel injector for applications related to internal combustion engines. For atomization modeling, Eulerian Lagrangian Spray Atomization (ELSA) model is used. The model solves for volume fraction of liquid fuel as well as liquid-gas interface surface density to describe the complete atomization process. In this thesis, flow inside the injector is also considered for subsequent study of atomization. The study presents the application of ELSA model to a typical diesel injector, both in the context of RANS and LES. The model is validated with the help of experimental data available from Engine Combustion Network (ECN). The ELSA model which is normally designed for diffused (unresolved) interfaces, where the exact location of the liquid-gas interface is not considered, is extended to work with Volume of Fluid (VOF) type formulation of two phase flow, where interface is explicitly resolved. The coupling is achieved with the help of Interface Resolution Quality (IRQ) criteria, that takes into account both the interface curvature and modeled amount of interface surface. ELSA model is developed first considering both phases as incompressible, the extension to compressible phase is also briefly studied in this thesis, resulting in compressible ELSA formulation that takes into account varying density in each phase. In collaboration with Imperial College London, the Probability Density Function (PDF) formulation with Stochastic Fields is also explored to study atomization. In modern fuel injection systems, quite oftenthe local pressure inside the injector falls below the vapor saturation pressure of the fuel, resulting in cavitation. Cavitation effects the external flow and spray formulation. Thus, a procedure is required to study the phase change as well as jet formulation using a single and consistent numerical setup. A method is developed in this thesis that couples the phase change inside the injector to the external jet atomization. This is achieved using the volume of fluid formulation where the interface is considered between liquid and gas; gas consists of both the vapor and non condensible ambient air
Arico, Cassandra. "Micro-supercondensateurs à porosité contrôlée pour des applications à forte densité d’énergie sur substrats rigide et flexible." Thesis, Lille 1, 2020. http://www.theses.fr/2020LIL1I055.
Повний текст джерелаContinuous development and further miniaturization of electronic devices greatly stimulate the research for miniaturized and compact electrochemical energy storage (EES) devices, allowing thus the development of autonomous, sustainable and connected devices. Small footprint storage sources should be sufficient efficient in terms of power, autonomy and lifespan and fixed directly on chip. To fulfil the requirements, the combination of a micro-battery (μ-Bat) with a micro- supercapacitor (μ-SC) would constitute an ideal EES microdevice where μ-Bat is dedicated to long-term applications and μ-SC ensures power demand. As promising electrode candidate for high power microdevice, carbide-derived carbons (CDCs) have been identified to load to important capacitance gains. In addition, niobium oxide (Nb2O5) stores higher levels of charges and offers the prospect of achieving energy densities of Li-ion battery materials but with the ability to operate at high power. In the present study, Nb2O5 thin films were deposited on silicon wafer by sputtering and crystallized by a rapid thermal annealing into an orthorhombic phase T-Nb2O5. We investigated porous T-Nb2O5 in which rapid insertion of lithium throughout the entire material. Then, titanium carbide (TiC) thin films were deposited on silicon wafer by sputtering and partial chlorinated into strongly adherent TiC-CDC films. Hybrid micro-supercapacitors CDC/Nb2O5 were successfully prepared and characterized in 1M LiClO4 (EC/DMC : 1/1). Finally, direct laser writing onto KaptonTM of Nb2O5 and carbon-based electrodes open the way for the design of flexible micro-supercapacitors
Madkour, Jaouad. "Modèles non linéaires et prévision." Phd thesis, Université d'Orléans, 2013. http://tel.archives-ouvertes.fr/tel-00912861.
Повний текст джерелаLee, Eunkyung. "IMPACT OF A 16-WEEK BEHAVIORAL WEIGHT-LOSS PROGRAM ON DIETARY AND PHYSICAL ACTIVITY CHANGES." UKnowledge, 2010. http://uknowledge.uky.edu/gradschool_theses/54.
Повний текст джерелаDumitrescu, Elena. "Econometric Methods for Financial Crises." Thesis, Orléans, 2012. http://www.theses.fr/2012ORLE0502/document.
Повний текст джерелаKnown as Early Warning Systems (EWS), financial crises forecasting models play a key role in definingeconomic policies at microeconomic, macroeconomic and international level. However, in the wake ofthe global financial crisis, numerous questions with respect to their forecasting abilities have been raised,as very few signals were drawn prior to the starting of the turmoil. Two questions arise in this context:how to evaluate EWS forecasting abilities and how to improve them?The broad goal of this applied econometrics dissertation is hence (i) to propose a systematic model-free evaluation methodology for the forecasting abilities of EWS as well as (ii) to introduce new EWSspecifications with improved out-of-sample performance. This work has been concretized in four chapters.The first chapter introduces a new approach to evaluate interval forecasts which relies on the binomialdistributional assumption of the violations series. The second chapter proposes an econometric evaluationmethodology of the forecasting abilities of an EWS. We show that adequate evaluation must take intoaccount the cut-off both in the optimal crisis forecast step and in the model comparison step. The thirdchapter points out that crisis dynamics (persistence) is essential for the econometric specification of anEWS. Indeed, dynamic logit models lead to better out-of-sample forecasting probabilities than those oftheir main competitors (static model and Markov-switching one). Finally, a multivariate dynamic probitEWS is proposed in the fourth chapter to take into account the causality between different types of crises(banking, currency, sovereign debt). The empirical application shows that the trivariate model improvesforecasts for countries that underwent the three types of crises
Matoso, Fabiano da Silva. "PrediÃÃo das propriedades fÃsico-quÃmicas do Ãster etÃlico do Ãleo de mamona (EEOM)." Universidade Federal do CearÃ, 2013. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=13000.
Повний текст джерелаAs propriedades fÃsico-quÃmicas do Ãster EtÃlico do Ãleo de Mamona (EEOM) foram estimadas a partir de modelos teÃricos e anÃlises experimentais. Por nÃo ser um combustÃvel comercial, o EEOM foi manufaturado por meio de um processo de fabricaÃÃo denominado (Transesterification Double Step Process) TDPS. AtravÃs do mÃtodo de contribuiÃÃo de grupos, as propriedades crÃticas e o ponto de ebuliÃÃo normal foram estimados. Utilizando os valores das propriedades crÃticas e correlaÃÃes matemÃticas, estimaram-se a tensÃo superficial, a entalpia de vaporizaÃÃo, a pressÃo de vapor, a condutividade tÃrmica, a viscosidade e a densidade. A anÃlise experimental do EEOM foi conduzida utilizando tÃcnicas tradicionalmente associadas à pesquisa de densidade e viscosidade de combustÃveis. Na anÃlise experimental de viscosidade utilizou-se um viscosÃmetro copo Ford. TambÃm foram analisadas experimentalmente as misturas ternÃrias do EEOM, etanol e diesel comercial em diversas fraÃÃes volumÃtricas. A anÃlise das misturas ternÃrias vem como uma alternativa para amenizar os valores de viscosidade e densidade do EEOM no combustÃvel de uso final, estimando os valores de fraÃÃes volumÃtricas que podem atender as normas brasileiras e europeias. Os resultados das propriedades fÃsico-quÃmicas servirÃo como base para rotinas computacionais de simulaÃÃo aplicadas ao estudo de emissÃes de poluentes e formaÃÃo do jato combustÃvel para o EEOM.
The physicochemical properties of the Ethyl Ester of Castor Oil (EECO) were estimated from theoretical models and experimental analysis. As it is not a comercial fuel, the EECO has been manufactured by a special fabrication process denominated (Transesterification Double Step Process) TDPS. Through the group contribution method, critical properties and normal boiling point were estimated. Using the values of the critical properties and mathematical correlations, were surface tension, enthalpy vaporization, vapor pressure, thermal conductivity, viscosity and density estimated. The experimental analysis of EEOM was conducted using techniques traditionally associated with research of density and viscosity of fuel. In the experimental analysis of viscosity it was used a Ford cup viscometer. As an alternative to alleviate the values of viscosity and density of the fuel EECO in ultimate use, as well as analyzed mixtures EECO, ethanol and diesel trade in various volume fractions, estimating the values that can meet the Brazilian and European standards. The results of the physical and chemical properties will serve as a basis for computer simulation routines applied to the study of emissions and formation of jet fuel for EECO.
Vergílio, Paula Cristina Benetton. "Relações entre estrutura, química e densidade da casca com sua função em caules e raízes de espécies do cerrado paulista." Botucatu, 2019. http://hdl.handle.net/11449/181310.
Повний текст джерелаResumo: A casca é um sistema biológico complexo que desempenha diversas funções na planta, incluindo condução de fotoassimilados, suporte mecânico, armazenamento de substâncias e proteção contra herbívoros, patógenos e intempéries como o fogo. A casca é composta, principalmente, pelo floema secundário e pela periderme, e reveste tanto caules quanto raízes. O caule está exposto à atmosfera e tem funções de elevação e suporte da planta, enquanto a raiz está exposta ao solo e tem funções de fixar a planta ao solo, armazenar substâncias e absorver e conduzir água e nutrientes. Contudo, pouco se sabe se as diferentes funções de caules e raízes indicam diferentes funções na casca de cada órgão. Neste trabalho, comparamos a casca de caules e raízes de 15 espécies representativas do cerrado paulista e testamos se a casca do caule apresentaria funções de suporte e proteção, enquanto a casca da raiz apresentaria função de armazenamento de substâncias. Também testamos se encontraríamos maior eficiência na condução de fotoassimilados na casca da raiz. Para tanto, selecionamos 15 espécies de árvores e arbustos do cerrado sensu stricto e amostramos a casca do caule e da raiz. Analisamos a estrutura (espessura e anatomia), a densidade e a química (água, açúcares solúveis, amido, nitrogênio, fósforo e carbono) e relacionamos com as funções da casca em cada órgão. Na casca do caule, encontramos maior espessura da periderme, devido ao felema mais largo com células maiores e mais espessas, e menor dens... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: Bark is a complex biological system that performs multiple functions in plant, including photoassimilates conduction, mechanical support, storage and protection against herbivores, pathogens and fire. Bark comprises mainly the secondary phloem and the periderm, and covers both trunks and roots. The trunk is exposed to the atmosphere and has the main functions of plant elevation and plant support, whereas the root is exposed to the ground and has the main functions of fix the plant to the ground, store substances, provide water and nutrients to the plant. However, remain unclear whether the different functions of trunk s and roots indicate different functions in the bark of each organ. In this work, we compared the bark of trunk and roots of species in the cerrado of São Paulo, tested whether the trunk bark presents both support and protection functions, whereas the root bark presents storage function. We also tested whether we would find higher efficiency of photoassimilates conduction in the root bark. For this purpose, we selected 15 representative species of trees and shrubs in the cerrado sensu stricto and sample both trunk and root barks. We analyzed the structure (thickness and anatomy), density and chemistry (water, soluble sugars, starch, nitrogen, phosphorus and carbon) and associated to the bark functions in each organ. In the trunk bark, we found thicker periderm, due to thicker phellem with larger cell and thicker wall cells, and lower periderm density, suggesting... (Complete abstract click electronic access below)
Doutor
Vestin, Albin, and Gustav Strandberg. "Evaluation of Target Tracking Using Multiple Sensors and Non-Causal Algorithms." Thesis, Linköpings universitet, Reglerteknik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-160020.
Повний текст джерелаLai, Jung-Pin, and 賴榮斌. "Relationship between TMJ internal derangement, BMI, Bone mineral density, craniofacial morphology in young females." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/38833561475624424072.
Повний текст джерела國立臺灣大學
臨床牙醫學研究所
96
Objectives: Prevalence of TMJ internal derangement (ID) in general population is relatively high (up to 32%). TMJ ID is often associated with joint noise, pain during mouth opening, and difficulty in chewing. Problems in TMJ ID possibly include changes in craniofacial morphology and malocclusion. From our previous study, disc displacement without reduction (DDNR) is significantly correlated with low bone mineral density and low body mass index. Therefore, high prevalence rate of TMJ ID and other associated changes may cause major health problems and needs our attention. Diagnosis rate of TMJ ID is under estimated because there is no general physical examination which can evaluate TMJ ID precisely. MRI, being used for correct diagnosis of TMJ ID, costs much and therefore, is not practical to apply on every patient. Thus, an easier and convenient method but with less cost should be developed for diagnosis of TMJ ID. The aim of this study was to explore correlations of TMJ ID and morphological differences of craniofacial structure, and to explore systemic risk factors of TMJ ID. A screening method for TMJ ID with different variables was derived for three populations of patients. Materials and methods: A total of 156 young females (18 to 28 years old) participated in this cross-sectional study. Samples were collected from: 1) TMD department, 2) orthodontic department of NTUH, and 3) general young females without any symptoms of TMD. Both static and dynamic TMJ MRI was used for the correct diagnosis of TMJ ID. Condylar head area (CHA) and ascending ramus height (ARH) were measured on the images from static TMJ MRI. The craniofacial morphology of the subjects was assessed by using both lateral and PA cephalograms. The bone mineral density in the lumbar spines was obtained by using dual energy X-ray absorptiometry (DXA). BMI was calculated using the body height and weight (height/weight2). Chi square and multivariate regression analysis were used for the statistical analyses. Results: There was significant difference in diagnosis and distributions TMJ ID among three populations. In orthodontic department, 64.10% of population was diagnosed with ID at either side of TMJ and 50% of total condyles were diagnosed as TMJ ID. In TMD department, 96.43% of population was diagnosed with ID at either side of TMJ and 83.04% of total condyles were diagnosed as TMJ ID. In general young female population, 45.45% was diagnosed with ID at either side of TMJ and 34.85% of total condyles were diagnosed as TMJ ID. Prevalence of TMJ ID was highest in the population from TMD department, subsequently followed by the population from orthodontic department. The prevalence of TMJ ID in general young females were the lowest but still with one third of the joints affected. Multivariate regression model showed that small condyle head area, narrow condyle width, and short condyle length were associated with higher risks for TMJ ID. The smaller the condyle head was with higher possibility for TMJ ID. Patients with class II and class III skeletal jaw relationships were much prone to have TMJ ID than those with normal one. Especially, asymmetry in upper and lower jaws was with higher risks for TMJ ID. In addition, skeletal class II with large overjet was highly associated with disc displacement without reduction. Conclusion: There were significant differences in diagnosis and distribution of TMJ ID among three populations. TMJ ID was associated with specific changes in craniofacial morphology. Therefore, the characteristics of craniofacial morphology associated with higher risks for TMJ ID should be notified in different clinics for patient health benefits.
Shaffer, Leslie Brooke. "Examining Regression Analysis Beyond the Mean of the Distribution using Quantile Regression: A Case Study of Modeling the Internal Bond of Medium Density Fiberboard using Multiple Linear Regression and Quantile Regression with an Example of Reliability Methods using R Software." 2007. http://etd.utk.edu/2007/ShafferLeslie.pdf.
Повний текст джерелаHU, WEI-YUAN, and 胡偉元. "A Beta approximation of unimodal density in finite interval." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/63624695121315318147.
Повний текст джерела國立臺北大學
統計學系
97
Reliability is the probability that a component or a system can function at designed level during some specified period of time. When the distribution of component lifetime is unknown, nonparametric methods are used to estimate the system reliability, Rs(t)=P{T≥t}. Due to the randomization of sampling, the reliability of a component varies from lot to lot. In order to describe further the variation and uncertainty of the reliability, it can be viewed as a random variable, also called believed-reliability, which is often assumed to be distributed as a Beta distribution. The purpose of this research is to present a numerical method to evaluate system believed-reliability by component believed-reliabilities under the circumstance that components distributed as Beta function independently and through the system structure function. Let the believed-reliabilities of two components at time t be independent random variables X~Beta(α1,β1) and Y~Beta(α2,β2), α1, β1, α2, β2 > 0. This research first discusses the case of a series composed of two components to find the Beta approximation for the believed-reliability, Z=XY by minimizing the L1-norm between the density functions, and then extends it to the case of the series and parallel composed of n components. The Beta approximation of the believed-reliability for the system composed of series, parallel, series-parallel and parallel-series configuration can be derived by the previous methods.
Pantoja, Galicia Norberto. "Interval Censoring and Longitudinal Survey Data." Thesis, 2007. http://hdl.handle.net/10012/3224.
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