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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Josef Cheth Novotný - osobnost a dílo / Josef Cheth Novotný - personality and work

Drašnarová, Sylva January 2014 (has links)
This diploma thesis is the first biography about a journalist and writer Josef Novotný, who was born in Chrudim of 1900, considered one of the culturally liveliest Czech towns at the sunset of the 19th century. He engaged in writing as early as at grammar school, gaining first journalist experience in regional press, above all in Středostavovský buditel. This periodical was published by Československá živnostensko-obchodnická strana středostavovská. In the following years he worked as a reporter in Nová Praha, Trn, Tramp, Úl and others. In the 30s he started cooperation with Melantrich, where he wrote for České slovo and Český ilustrovaný zpravodaj. Later on in the late 40s he was employed as a reporter with Masarykův list. In 1948 his membership in Sydnikát českých novinářů had expired and by that literally his journalist career, too. He wrote tens of books, some of which were of autobiographic and regional character. He is the author of literature for children and youth, theatre and puppet plays, detective stories and rodokaps. He elaborated many historical themes and literary criticism essays. The biggest acknowledgement he received for his novel Piava based on his experiences from the frontline during the First World War. Most of his life work has never been published and is archived in the...
42

Pavel a Izrael podle epištoly Galatským / Paul and Israel in the Epistle to Galatians

Ženatý, Filip January 2012 (has links)
This paper deals with a question, how the apostle Paul saw the Christian church in relation to Israel as a people of God in the epistle to the Galatians. As it is an epistle written for a particular reason to the particular people, the first part of the paper deals with a brief analysis of the epistle as such and its context. The main part of the paper is focused on Paul's specific arguments. The role of Paul's conversion, his mission among the gentiles and his relationship with the Jerusalem authorities are evaluated at first. The paper clarifies also what the Antioch incident was about. What follows is the crucial analysis of the term "works of the Law", against which Paul places the faith alone. The paper subsequently focuses on the exposition of the role of Abraham in Paul's theological thoughts. How Paul saw the curse of the Law and how he understood the Jewish Law as such is examined as well. Paul's concept of the church as the newly redefined people of God is demonstrated on the idea of the freedom in the end.
43

A Numerical Study of Compressible Lid Driven Cavity Flow with a Moving Boundary

Hussain, Amer 13 May 2016 (has links)
A two-dimensional (2-D), mathematical model is adopted to investigate the development of circulation patterns for compressible, laminar, and shear driven flow inside a rectangular cavity. The bottom of the cavity is free to move at a specified speed and the aspect ratio of the cavity is changed from 1.0 to 1.5. The vertical sides and the bottom of the cavity are assumed insulated. The cavity is filled with a compressible fluid with Prandtl number, Pr =1. The governing equations are solved numerically using the commercial Computational Fluid Dynamics (CFD) package ANSYS FLUENT 2015 and compared with the results for the primitive variables of the problem obtained using in house CFD code based on Coupled Modified Strongly Implicit Procedure (CMSIP). The simulations are carried out for the unsteady, lid driven cavity flow problem with moving boundary (bottom) for different Reynolds number, Mach numbers, bottom velocities and high initial pressure and temperature.
44

Instabilidade hidrodinâmica linear do escoamento compressível em uma cavidade / Linear hidrodinamic instability of compressible lid-driven cavity flow

Bergamo, Leandro Fernandes 28 April 2014 (has links)
Os mecanismos de instabilidade hidrodinâmica têm um papel importante no processo da transição do escoamento de laminar para turbulento. A análise da instabilidade hidrodinâmica em uma cavidade com tampa deslizante foi realizada através da decomposição em modos globais (biglobal) para avaliar o efeito da compressibilidade neste fenômeno. O escoamento base foi obtido através de simulação numérica direta (DNS). Para tal, foi desenvolvido um código DNS compressível com discretização espacial por diferenças finitas compactas de alta resolução espectral e capacidade de processamento paralelo, com um método de decomposição de domínio que mantém a precisão das diferenças finitas compactas. O escoamento base é usado para montar o problema de autovalor oriundo das equações de Navier-Stokes linearizadas para a perturbação, discretizadas por diferenças finitas explícitas. O uso de diferenças finitas em conjunto com a implementação em matrizes esparsas reduz sensivelmente o uso de memória. Através do algoritmo de Arnoldi, a ordem do problema de autovalor é reduzida e os autovalores de interesse são recuperados. Os resultados indicam o efeito estabilizante da compressibilidade nos modos dominantes da cavidade e revelam modos inerentes ao escoamento compressível, para os quais a compressibilidade tem efeito desestabilizante. Dentre estes modos compressíveis, estão presentes modos de propagação sonora em dutos e modos relacionados à geração de som na cavidade. / Hydrodynamic instability mechanisms play an important role in laminar to turbulent transition. Hydrodynamic instability analysis of a lid-driven cavity flow was performed by global mode decomposition (biglobal) to evaluate compressibility effects on this phenomenon. The basic flow was calculated by direct numerical simulation (DNS). A compressible DNS code was developed with spectral-like compact finite difference spatial discretization. The code allows parallel processing with a domain decomposition method that preserves the compact finite difference accuracy. The basic flow is used to form the eigenvalue problem associated to the linear Navier- Stokes equations for the perturbation, which were discretized by an explicit finite difference scheme. The combination of sparse matrix techniques and finite difference discretization leads to a significant memory reduction. The order of the eigenvalue problem was reduced using the Arnoldi algorithm and the eigenvalues of interest were calculated. Results show the stabilizing effect of compressibility on the leading modes and reveal some modes intrinsic to compressible flow, for which compressibility has a destabilizing effect. Among these compressible modes, there are some related to sound propagation in ducts and to sound generation inside the cavity.
45

Instabilidade hidrodinâmica linear do escoamento compressível em uma cavidade / Linear hidrodinamic instability of compressible lid-driven cavity flow

Leandro Fernandes Bergamo 28 April 2014 (has links)
Os mecanismos de instabilidade hidrodinâmica têm um papel importante no processo da transição do escoamento de laminar para turbulento. A análise da instabilidade hidrodinâmica em uma cavidade com tampa deslizante foi realizada através da decomposição em modos globais (biglobal) para avaliar o efeito da compressibilidade neste fenômeno. O escoamento base foi obtido através de simulação numérica direta (DNS). Para tal, foi desenvolvido um código DNS compressível com discretização espacial por diferenças finitas compactas de alta resolução espectral e capacidade de processamento paralelo, com um método de decomposição de domínio que mantém a precisão das diferenças finitas compactas. O escoamento base é usado para montar o problema de autovalor oriundo das equações de Navier-Stokes linearizadas para a perturbação, discretizadas por diferenças finitas explícitas. O uso de diferenças finitas em conjunto com a implementação em matrizes esparsas reduz sensivelmente o uso de memória. Através do algoritmo de Arnoldi, a ordem do problema de autovalor é reduzida e os autovalores de interesse são recuperados. Os resultados indicam o efeito estabilizante da compressibilidade nos modos dominantes da cavidade e revelam modos inerentes ao escoamento compressível, para os quais a compressibilidade tem efeito desestabilizante. Dentre estes modos compressíveis, estão presentes modos de propagação sonora em dutos e modos relacionados à geração de som na cavidade. / Hydrodynamic instability mechanisms play an important role in laminar to turbulent transition. Hydrodynamic instability analysis of a lid-driven cavity flow was performed by global mode decomposition (biglobal) to evaluate compressibility effects on this phenomenon. The basic flow was calculated by direct numerical simulation (DNS). A compressible DNS code was developed with spectral-like compact finite difference spatial discretization. The code allows parallel processing with a domain decomposition method that preserves the compact finite difference accuracy. The basic flow is used to form the eigenvalue problem associated to the linear Navier- Stokes equations for the perturbation, which were discretized by an explicit finite difference scheme. The combination of sparse matrix techniques and finite difference discretization leads to a significant memory reduction. The order of the eigenvalue problem was reduced using the Arnoldi algorithm and the eigenvalues of interest were calculated. Results show the stabilizing effect of compressibility on the leading modes and reveal some modes intrinsic to compressible flow, for which compressibility has a destabilizing effect. Among these compressible modes, there are some related to sound propagation in ducts and to sound generation inside the cavity.
46

Life-Cycle-Cost Analysis of using Low Impact Development Compared to Traditional Drainage Systems in Arizona: Using Value Engineering to Mitigate Urban Runoff

January 2019 (has links)
abstract: The rate of urbanization has been impacted by global economic growth. A strong economy results in more people moving to already crowded urban centers to take advantage of increased employment opportunities often resulting in sprawling of the urban area. More natural land resources are being exploited to accommodate these anthropogenic activities. Subsequently, numerous natural land resources such as green areas or porous soil, which are less flood-prone and more permeable are being converted into buildings, parking lots, roads and underground utilities that are less permeable to stormwater runoff from rain events. With the diminishing of the natural landscape that can drain stormwater during a rainfall event, urban underground drainage systems are being designed and built to tackle the excess runoff resulting from urbanization. However, the construction of a drainage system is expensive and usually involves massive land excavations and tremendous environmental disturbances. The option for constructing an underground drainage system is even more difficult in dense urban environments due to the complicated underground environments, creating a need for low footprint solutions. This need has led to emerging opportunities for low impact development (LID) methods or green infrastructures, which are viewed as an environmentally friendly alternative for dealing with stormwater runoff. LID mimics the pre-development environment to retain the stormwater runoff through infiltration, retention, detention and evaporation. Despite a significant amount of prior research having been conducted to analyze the performance of runoff volume reduction and peak flow decrement of various green infrastructures, little is known about the economic benefits of using LID practices. This dissertation fills the gap in the knowledge regarding the life-cycle-cost effectiveness of green infrastructure in current urban developments. This study’s two research objectives are: (1) Develop a life cycle cost calculation template to analyze the cost benefits of using LID compared to the traditional drainage system (2) Quantify the cost benefits based on the real-world construction projects A thorough literature review led to the data collection of the hydrological benefits of using LIDs in conjunction with overviewing three real-world construction projects to quantify the cost benefits of LIDs. / Dissertation/Thesis / Doctoral Dissertation Civil, Environmental and Sustainable Engineering 2019
47

Numerical Investigation Of The Viscoelastic Fluids

Yapici, Kerim 01 July 2008 (has links) (PDF)
Most materials used in many industries such as plastic, food, pharmaceuticals, electronics, dye, etc. exhibit viscoelastic properties under their processing or flow conditions. Due to the elasticity of such materials, deformation-stress in addition to their hydrodynamic behavior differ from simple Newtonian fluids in many important respects. Rod climbing, siphoning, secondary flows are all common examples to how a viscoelastic fluid can exhibit quite distinctive flow behavior than a Newtonian fluid would do under similar flow conditions. In industrial processes involving flow of viscoelastic materials, understanding complexities associated with the viscoelasticity can lead to both design and development of hydrodynamically efficient processes and to improved quality of the final products. In the present study, the main objective is to develop two dimensional finite volume based convergent numerical algorithm for the simulation of viscoelastic flows using nonlinear differential constitutive equations. The constitutive models adopted are Oldroyd-B, Phan-Thien Tanner (PTT) and White-Metzner models. The semi-implicit method for the pressure-linked equation (SIMPLE) and SIMPLE consistent (SIMPLEC) are used to solve the coupled continuity, momentum and constitutive equations. Extra stress terms in momentum equations are solved by decoupled strategy. The schemes to approximate the convection terms in the momentum equations adopted are first order upwind, hybrid, power-law second order central differences and finally third order quadratic upstream interpolation for convective kinematics QUICK schemes. Upwind and QUICK schemes are used in the constitutive equations for the stresses. Non-uniform collocated grid system is employed to discretize flow geometries. As test cases, three problems are considered: flow in entrance of planar channel, stick-slip and lid driven cavity flow. Detailed investigation of the flow field is carried out in terms of velocity and stress fields. It is found that range of convergence of numerical solutions is very sensitive to the type of rheological model, Reynolds number and polymer contribution of viscosity as well as mesh refinement. Use of White-Metzner constitutive differential model gives smooth, non oscillatory solutions to much higher Weissenberg number than Oldroyd-B and PTT models. Differences between the behavior of Newtonian and viscoelastic fluids for lid-driven cavity, such as the normal stress effects and secondary eddy formations, are highlighted. In addition to the viscoelastic flow simulations, steady incompressible Newtonian flow of lid-driven cavity flow at high Reynolds numbers is also solved by finite volume approach. Effect of the solution procedure of pressure correction equation cycles, which is called inner loop, on the solution is discussesed in detail and results are compared with the available data in literature.
48

Análise da influência de variantes do método de solução de escoamentos utilizando os métodos de elementos finitos com compressibilidade artificial e pseudo-características

Oliveira, Marcos Paulo de Carvalho [UNESP] 31 August 2007 (has links) (PDF)
Made available in DSpace on 2016-04-01T17:54:43Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-08-31. Added 1 bitstream(s) on 2016-04-01T18:00:22Z : No. of bitstreams: 1 000505957.pdf: 1448129 bytes, checksum: ef6c3d75951b3a630e2efdba48bcb784 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O desenvolvimento de modelos numéricos para simulação de escoamentos tem se dado em diversos aspectos: desde os métodos de acoplamento entre pressões e velocidades até as técnicas de estabilização da solução. Neste contexto, este trabalho se propõe a implementar e avaliar o comportamento de um destes algoritmos, o CBS, utilizando-o na simulação de um escoamento isotérmico de fluido incompressível. Para tanto, foram utilizados variantes do esquema de solução com relação à discretização no tempo, com os métodos explícito e semi-implícito, além de algumas outras alterações na discretização no espaço e nos termos de estabilização. A discretização geral do problema foi feita com o método dos elementos finitos utilizando-se uma malha formada por elementos bilineares. O algoritmo e suas variações foram avaliados através de uma série de resultados, para diversos valores do número de Reynolds, de um problema clássico: a cavidade recirculante. Desta forma, foi possível mostrar que todas as variações da solução usando a malha estabelecida apresentaram concordância satisfatória com os resultados da literatura. Além disto, verificou-se que a omissão do termo característico não apresentou diferenças significativas nos resultados para os valores de número de Reynolds testados. Os resultados mostraram também que o método semi-implícito converge com um menor número de incrementos de tempo que o método explícito. / The development of numerical models for fluid flow simulation occurred at many aspects: since coupling methods between pressures and velocities until stabilization techniques. In this context, this work intends to implement and evaluate one algorithm behavior, the CBS, used in a simulation of incompressible and isothermal flows. This work also uses the explicit and semi-implicit methods of the time discretization scheme and some others changes in space discretization and stabilization terms for tests with algorithm. The discretization technique used is the finite element method with the mesh formed by bilinear elements. The algorithm's changes were evaluated using results for several Reynold's number in a classic problem: the lid-driven cavity. All the changes in solution algorithm with the used mesh show good agreement with other results from bibliography. It was verified too, that the omission of characteristics term didn't present significant differences in results with Reynold's number tested. It was observed yet that the solution code using the semi-implicit method converges with less time steps than the explicit one.
49

INFLUENCIA DE LA COMPOSICIÓN Y ESTRUCTURA DE LOS SUBSTRATOS DE SILICIO MONOCRISTALINO EN EL COMPORTAMIENTO ELÉCTRICO DE LAS CÉLULAS FOTOVOLTAICAS CRISTALINAS DE ALTA EFICIENCIA

Cascant López, Miguel 08 April 2016 (has links)
[EN] Crystalline silicon solar cell performance and durability is highly influenced by substrate structure and composition. In this sense, the presence of impurities and lattice imperfections degrades the electrical behavior of the substrates limiting the power conversion efficiency potential of photovoltaic devices. The influence of material electrical behavior on device performance, is further increased in next generation silicon solar cells demanding high quality substrates to reach high efficiency. A industrial-like Czochralski (Cz) p-type, ingot was grown and sawed in wafers with resistivity ranging from 0.7 Ohm.cm to 2.1 Ohm.cm and thicknesses of 200 µm. The characterization of the radial and longitudinal distribution of resistivity as well as carbon, oxygen and iron content lead to a broad characterization ot the impurity distribution at the ingot level. The low carbon content ([C]<5E15 cm-3) contrasts with remarkable high interstitial oxygen (Oi). On the other hand, while effective carrier lifetime is not significativelly affected by the high Oi content, low Fei concentrations in the ingot tail ([Fei]>1E11 cm-3) and surface ([Fei]>1E12 cm-3) led to significant lifetime degradation. In addition, lifetime mapping of the tail of the ingot showed high density of crystal dislocations. The influence of the boron and phosphorus diffusion on the electrical performance of silicon substrates was studied. Phosphorus diffusion from a POCl3 source showed a beneficial effect on lifetime that was associated with the reduction of Fei content (external gettering effect). On the other hand, boron diffusion from a BCl3 source revealed a detrimental effect that could be related to a substantial increase of [Fei] in the range of one order of magnitude. A process sequence including consecutive boron and phosphorus diffusions showed a substantial degradation of lifetime at the ingot top that could be explained by Oi precipitation rings. The influence of the crystal defects, found at the ingot tail, on lifetime degradation after the diffusion processes was also confirmed. Al-BSF cells were manufactured from a batch of wafers extracted along the ingot with efficiencies ranging between 17.8% and 18.2% and showing low dependence of solar cell performance on the solidified fraction of the ingot. Internal Quantum Efficiency (IQE) and minority carrier diffusion length (Ld) mappings further confirmed the external gettering effect developed by the phosphorus diffusion. In a further stage, Passivated Emiteer Rear Totally-diffused (PERT) cells were manufactured with efficiencies in the range of 18.8% and 19.6%. As opposed to Al-BSF cells, electrical parameters of PERT cells were influenced by solidified fraction with a reduction of cell performance near the top and tail of the ingot. In a later stage, an additional batch of solar cells of three different architectures, including Al-BSF, PERT and Passivated Emitter Rear Contact (PERC), was successfully manufactured from the same region of a Cz boron-doped ingot. Real time monitoring of the Voc enabled the study of the influence of the cell architecture on the Light Induced Degradation (LID) and Regeneration (LIR) kinetics and amplitudes. Strong correlation between the cell architectures and the degradation amplitude were observed with higher efficiency losses for PERC cells mainly due to a higher sensibility to bulk carrier lifetime degradation. In addition, the potential of LIR processes to permanently suppress the LID effects on the studied solar cell architectures was confirmed. Main causes driving the influence of the architecture in LID amplitude and LIR kinetics were further investigated. / [ES] Las características de los substratos sobre los que son fabricadas las células fotovoltaicas cristalinas constituyen un elemento fundamental en su comportamiento y durabilidad. En este sentido, la presencia de impurezas e imperfecciones en la red cristalina reduce el comportamiento eléctrico de los substratos limitando el potencial de generación eléctrica de las células. Esta limitación se acrecienta en las células de nueva generación, en las que su potencial para aumentar la eficiencia de conversión fotovoltaica solo puede hacerse efectivo al utilizar substratos con altas prestaciones eléctricas. En la presente investigación se ha procedido a la cristalización mediante la técnica Czochralski (Cz) de un lingote monocristalino, tipo p con resistividad en el rango de 0.7-2.1 Ohm.cm y tamaño industrial. Su posterior corte en obleas de 200 µm de espesor nominal ha permitido disponer de obleas distribuidas a lo largo del lingote en una fracción solidificada entre el 2.0% y el 99.4%. La caracterización del lingote ha incluido la medida de la resistividad así como la reconstrucción longitudinal y radial de su concentración en carbono, oxígeno y hierro. El reducido contenido en carbono obtenido ([C]<5E15 cm-3) contrasta con una elevada concentración en oxígeno intersticial (Oi) sin efectos apreciables en las propiedades eléctricas del lingote. Contrariamente, la reducción del tiempo de vida efectivo en la periferia y cola del lingote, es atribuido al aumento de la concentración en hierro intersticial [Fei] en dichas regiones. El estudio de la influencia de las difusiones en la evolución de las propiedades eléctricas del material incluyó difusiones de boro y fósforo mediante BCl3 y POCl3. El estudio ha constatado el efecto benéfico de la difusión de fósforo en la periferia del lingote asociado a la reducción del contenido en Fei. Por el contrario, se ha constatado el efecto perjudicial de la difusión de boro explicado en buena medida por un aumento superior a un orden de magnitud en [Fei]. La aplicación sucesiva de difusiones de boro y fósforo ha revelado una degradación apreciable en la cabeza del lingote tras la aparición de patrones circulares en la medida del tiempo de vida característicos de la precipitación de Oi. Se ha podido constatar la influencia de la elevada densidad de dislocaciones, observada en la cola del lingote, en la respuesta del substrato ante las difusiones. La fabricación de células de tecnología Al-BSF, con eficiencias comprendidas entre 17.8% y 18.2%, ha evidenciado una reducida influencia de las variaciones de las propiedades eléctricas del substrato en el comportamiento de las células finales. A su vez, la cartografía de la eficiencia quántica interna (IQE) y de la longitud de difusión (Ld) ha confirmado el efecto benéfico de la difusión de boro en la periferia y cola del lingote. La fabricación de células Passivated Emiteer Rear Totally-difused (PERT), ha permitido la obtención de dispositivos con eficiencias entre 18.8% y 19.6%. Las eficiencias muestran valores máximos en el centro del lingote y una reducción apreciable en la cabeza y cola.En una última etapa, se ha procedido a la fabricación de arquitecturas de células fotovoltaicas Al-BSF, PERT y Passivated Emitter Rear Contact (PERC), con el objetivo de estudiar los procesos de degradación y regeneración asociados a la formación de pares boro-oxígeno (B-O). El estudio de la evolución de Voc con el tiempo ha constatado una dependencia de la amplitud de degradación y cinética de regeneración con la arquitectura de célula. En este sentido se ha observado una degradación significativamente superior en las células PERC principalmente atribuible a una mayor sensibilidad a degradaciones de la calidad del substrato. A su vez se ha confirmado el potencial de los procesos de regeneración inducidos por la luz para suprimir de manera permanente los efectos de la degradación inducida por la for / [CAT] Les característiques dels substrats sobre els quals són fabricades les cèl·lules fotovoltaiques cristal·lines constitueixen un element fonamental en el seu comportament i durabilitat. En aquest sentit, la presència d'impureses i imperfeccions en la xarxa cristal·lina redueix el comportament elèctric dels substrats limitant el potencial de generació elèctrica de les cèl·lules. Aquesta limitació es veu augmentada en les cèl·lules de nova generació, en què el seu potencial per augmentar l'eficiència de conversió fotovoltaica només pot fer-se efectiu mitjançant la utilització de substrats amb altes prestacions elèctriques. En la present investigació s'ha procedit a la cristal·lització mitjançant la tècnica Czochralski (Cz) d'un lingot monocristal·lí, tipus p amb resistivitat en l'interval de 0.7-2.1 Ohm.cm i mida industrial. El seu posterior tall en oblees de 200 micres de gruix nominal ha permès disposar d'oblees distribuïdes al llarg del lingot en una fracció solidificada entre el 2.0% i el 99.4%. La caracterització exhaustiva del lingot ha inclòs la mesura de la resistivitat així com la reconstrucció longitudinal i radial de la concentració en carboni, oxigen i ferro. El reduït contingut en carboni obtingut ([C]<5E15 cm-3) contrasta amb una elevada concentració d'oxigen intersticial (Oi) sense efectes apreciables en les propietats elèctriques del lingot. Contràriament, la reducció del temps de vida efectiu dels portadors de càrrega a la perifèria i cua del lingot, és atribuïda a l'augment de la concentració en ferro intersticial [Fei] en aquestes regions. L'estudi de la influència de les difusions en l'evolució de les propietats elèctriques del material va incloure difusions de bor i fòsfor mitjançant BCl3 i POCl3. L'estudi ha constatat l'efecte benèfic de la difusió de fòsfor en la perifèria del lingot associat a la reducció del contingut en Fei. Per contra, s'ha constatat l'efecte perjudicial de la difusió de bor explicat en bona mesura per un augment superior a un ordre de magnitud en [Fei]. L'aplicació successiva de difusions de bor i fòsfor ha revelat una degradació apreciable en el cap del lingot després de l'aparició de patrons circulars en la mesura del temps de vida efectiu característics de la precipitació d'Oi. Igualment s'ha pogut constatar la influència d'una elevada densitat de dislocacions, observada a la cua del lingot, en la resposta del substrat davant les difusions. La fabricació de cèl·lules de tecnologia A-BSF, amb eficiències compreses entre 17.8% i 18.2%, va permetre evidenciar una reduïda influència de les variacions de les propietats elèctriques del substrat en el comportament de les cèl·lules finals. Al mateix temps, la cartografia de l'eficiència quàntica interna (IQE) i de la longitud de difusió (Ld) ha confirmat l'efecte benèfic de la difusió de bor en la perifèria i cua del lingot. La fabricació de cèl·lules Passivated Emiteer Rear Totally-difused (PERT), ha permès l'obtenció de dispositius amb eficiències entre 18.8% i 19.6%. Les eficiències mostren valors màxims al centre del lingot i una reducció apreciable en el cap i cua. En una última etapa, s'ha procedit a la fabricació d'arquitectures de cèl·lules fotovoltaiques Al-BSF, PERT i Passivated Emitter Rear Contact(PERC), amb l'objectiu d'estudiar els processos de degradació i regeneració associats a la formació de parells bor-oxigen (B-O). L'estudi de l'evolució de Voc amb el temps s'ha constatat una dependència de l'amplitud de degradació i cinètica de regeneració amb l'arquitectura de cèl·lula. En aquest sentit es va observar una degradació significativament superior en les cèl·lules PERC principalment atribuïble a una major sensibilitat a degradacions de la qualitat del substrat. Al mateix temps es va confirmar el potencial dels processos de regeneració induïts per la llum, per suprimir de manera permanent els efectes de la degradaci / Cascant López, M. (2016). INFLUENCIA DE LA COMPOSICIÓN Y ESTRUCTURA DE LOS SUBSTRATOS DE SILICIO MONOCRISTALINO EN EL COMPORTAMIENTO ELÉCTRICO DE LAS CÉLULAS FOTOVOLTAICAS CRISTALINAS DE ALTA EFICIENCIA [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/62356 / TESIS
50

The cardiovascular and cerebrovascular effects of laryngoscopy and endotracheal intubation in neonatal piglets, and the modification of these effects by topical lignocaine

Belfort, M A 08 May 2017 (has links)
No description available.

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