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1
Tieriekhov, Kostiantyn. "Applications non-conventionnelles de champs magnétiques à séparation chirale et aux systèmes électrochimiques dynamiques." Electronic Thesis or Diss., Bordeaux, 2023. http://www.theses.fr/2023BORD0502.
Abstract:
L’énantioséparation de précision est essentielle pour les industries pharmaceutiques et alimentaires. Les techniques conventionnelles de séparation chirale offrent un large éventail de méthodes, qui reposent toutes sur des sélecteurs chiraux - des phases stationnaires ou des molécules qui distinguent les énantiomères par une interaction stéréospécifique. Malgré le grand nombre de sélecteurs naturels et synthétiques actuellement utilisés, la demande croissante d’énantiopurité stimule la recherche de nouvelles méthodes polyvalentes.Le but de cette thèse est d'étudier des méthodes alternatives de séparation chirale impliquant l'application de champs magnétiques dans diverses configurations. Une idée est centrée sur le concept de vraie et fausse chiralité, introduit par L. Barron pour les systèmes dynamiques d'objets individuels et de grandeurs physiques vectorielles. Sa discussion indique explicitement que ni les champs magnétiques ni électriques statiques, ni aucune combinaison de ceux-ci, ne possèdent une véritable chiralité, la caractéristique requise pour induire une discrimination énantiomérique. Cependant, sa théorie suggère l’existence d’un analogue moléculaire de l’effet Faraday bien connu sous forme de l’application colinéaire d’un champ magnétique à un flux moléculaire.Alternativement, une configuration perpendiculaire au flux moléculaire impliquant un substrat ferromagnétique a démontré des interactions de spin énantiospécifiques, également connues sous le nom d'effet CISS. À cet égard, notre objectif principal était d’explorer une telle interaction dans des conditions dynamiques d’électrophorèse capillaire, qui permet une détection simple et rapide, tout en introduisant des substrats de Ni le long du flux de molécules et en appliquant un champ magnétique orthogonal.Enfin, la configuration orthogonale du champ magnétique a été exploitée pour étudier le comportement dynamique d'objets électropolarisés. Il a été démontré que la rotation présenté par différents objets sous l'effet magnétohydrodynamique induit par la force de Lorentz dépendent de la polarité du champ magnétique. Leur comportement dynamique en fonction du temps ressemble à celui de systèmes faussement chirauxHigh-purity enantioseparation is essential for the pharmaceutical and food industries. Conventional chiral separation techniques provide a wide range of methods, all of which rely on chiral selectors - stationary phases or molecules that discriminate enantiomers through stereospecific interaction. Despite the vast number of natural and synthetic selectors currently in use, the increasing demand for enantiopurity is driving research for new and versatile methods.The aim of this thesis is to investigate alternative methods of chiral separation that involve the application of magnetic fields in various configurations. One idea centers around the concept of true and false chirality, which was introduced by L. Barron for dynamic systems of individual objects and physical vector quantities. His discussion explicitly states that neither static magnetic nor electric fields, nor any combination of those, possess true chirality, the feature required to induce enantiomeric discimination. However, his theory suggests a molecular analog of the well-known Faraday effect based on the collinear application of magnetic field to a molecular flow.Alternatively, a perpendicular configuration with the molecular flow involving a ferromagnetic substrate has demonstrated enantiospecific spin interactions, otherwise known as the CISS effect. In this regard, our main objective was the further exploration of such interactions in dynamic conditions of capillary electrophoresis, which provides simple and fast detection, while introducing Ni substrates along the flow of molecules and applying an orthogonal magnetic field.Lastly, the orthogonal configuration of the magnetic field was exploited to study the dynamic behavior of electropolarized objects. The patterns of the resulting rotation, exhibited by different objects under the influence of a magnetohydrodynamic effect, originating from the induced Lorentz force, are shown to be dependent on magnetic field polarity. Their dynamic behavior as a function of time resembles those of falsely chiral systems
2
Bruce, Henrik. "Formulation of Model Problem for Chirality Induced Spin Selectivity Effect." Thesis, Uppsala universitet, Materialteori, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-414026.
Abstract:
Spin dependent electron transport in chiral molecules, the so-called chirality induced spin selectivity (CISS) effect, have attracted much attention over the past few years. Experimentally the spin polarization has been detected, and there is a theoretical consensus on the necessity of both spin-orbit coupling and geometrical helicity in order to get a non-vanishing spin polarization. Several model Hamiltonians has been proposed to describe the CISSS effect, and while they can yield spin polarization agreeing with the experimentally observed magnitudes, they are relying on unrealistic values of the spin orbit interaction parameters. In recent years the importance of electron correlation has been emphasized. Thus, this thesis presents the general theory on how to treat the CISS effect as a many body problem, taking electron correlation into account. The Hamiltonian modelling is described and one approach on how to treat the helical structure of the molecule and the spin-orbit coupling is presented. Building on this thesis, further studies will hopefully lead to a first principle understanding of the CISS effect.
3
Stanley, Mishael. "Développement de Cellules Photovoltaiques à base de CIGS de haute performance sur substrats métalliques." Electronic Thesis or Diss., Paris Sciences et Lettres (ComUE), 2019. http://www.theses.fr/2019PSLEC023.
Abstract:
L’objectif de cette thèse est l’optimisation de cellules solaires à base de Cu(In,Ga)Se2 (CIGS) sur substrat métallique à très haut rendement (>20%). Les métaux ont généralement une meilleure tenue mécanique que le verre qui est un matériau fragile. Cela permet par exemple de réduire fortement leur épaisseur et d’obtenir des dispositifs photovoltaïques plus légers. De plus, si leur épaisseur est suffisamment réduite, ils deviennent conformables voire flexibles. Cependant, les substrats métalliques ont leurs propres inconvénients. Ils peuvent contenir des impuretés (ex : Fe) qui dégradent les propriétés électroniques du matériau absorbeur. De plus, leur coefficient de dilatation thermique n’est pas toujours adapté aux procédés d’élaboration à haute température du CIGS. Enfin les cellules CIGS déposées sur substrat verre bénéficient d’un apport de sodium, élément connu pour améliorer les propriétés du CIGS, et apporté par la diffusion de cet élément depuis le verre via le molybdène. L’objectif principal de cette thèse consiste à réaliser des cellules solaire à base de CIGS par la technique de coévaporation sur substrats métalliques ayant des performances les plus proches possibles des cellules sur substrats en verre sodocalcique (>20%). Les problématiques auxquelles cette thèse doit répondre sont le choix du substrat métallique, le blocage de la diffusion des impuretés contenues dans les substrats métalliques, l’assurance d’une adhésion forte au substrat, la réduction des contraintes résiduelles (permettant de garantir l’adhésion) et surtout l’optimisation de la couche de Mo adéquate permettant l’apport nécessaire d’élément alcalin (Na/K,…) pour un CIGS de haute performance et l’adaptation de l’absorbeur à ce type de substrat. En effet la qualité du CIGS sera fortement dépendante de la température de dépôt, de l’apport d’élément alcalin provenant du substrat et des gradients de composition In/Ga du contact arrière vers la surface du CIGS. Il est connu qu’il est nécessaire d’avoir un gradient de gallium dans la couche de CIGS afin d’obtenir des cellules à haut. Le dépôt de couches de CIGS par co-évaporation se fera par la méthode du « three-stage process ». Celle-ci consiste à déposer la couche en trois étapes bien définies. Il est important de bien maîtriser ce procédé afin de pouvoir obtenir un absorbeur de qualité pour les cellules solairesThe objective of this thesis is the optimization of solar cells based on Cu (In, Ga) Se 2 (CIGS) on high performance metal substrate (> 20%). Metals generally have better mechanical strength than glass which is a brittle material. This allows for example to significantly reduce their thickness and get lighter photovoltaic devices. Moreover, if their thickness is sufficiently reduced, they become conformable or flexible. However, the metal substrates have their own drawbacks. They may contain impurities (eg Fe) that degrade the electronic properties of the absorber material. Furthermore, their thermal expansion coefficient is not always suitable for methods of making high temperature CIGS. Finally CIGS cells on glass substrate have a sodium intake, known element for improving the properties of the CIGS, and brought by the spread of this element from the glass through the molybdenum. The main objective of this thesis is to make solar cells based on CIGS by co-evaporation technique on metal substrates having the closest possible performance of the cells on substrates of soda lime glass (> 20%). The problems that this thesis must meet are the choice of the metal substrate, blocking the diffusion of impurities in the metallic substrates, ensuring strong adhesion to the substrate, reducing residual stresses (to ensure adherence ) and especially the optimization of the Mo adequate layer allowing necessary intake of alkali metal element (Na / K, ...) for a high performance and adaptation CIGS absorber to this type of substrate. Indeed the quality of CIGS will be highly dependent on the deposition temperature of the intake of alkaline element from the substrate and composition gradients In / Ga the back contact to the surface of CIGS. It is known that it is necessary to have a gradient gallium in the CIGS layer in order to obtain cells high. The deposition of CIGS layers by co-evaporation method will be by the "three-stage process." This involves depositing the layer of three well-defined stages. It is important to control this process in order to get a quality absorber for solar cells
4
CIZEAU, JEANNICK. "Effet mutagene du cis-dichlorodiammineplatine(ii) chez drosophila melanogaster." Orléans, 1994. http://www.theses.fr/1994ORLE2014.
Abstract:
Le cis-dichlorodiammineplatine(ii) ou cis-ddp est une drogue antitumorale largement utilisee dans certaines therapies anticancereuses. Il reagit avec l'adn en formant des pontages intrabrins et interbrins avec les n7 des purines. Le cis-ddp a egalement une activite mutagene qui a ete determinee chez des bacteries et des cellules d'eucaryotes en culture. Le cis-ddp induit principalement des mutations ponctuelles. Nous avons etudie cet effet sur un organisme entier: drosophila melanogaster. Deux genes, white et vermilion, situes sur le chromosome x ont ete choisis comme cible de mutagenese car leur phenotype mute est facilement selectionnable. Afin d'etudier l'influence de la sequence homologue sur le spectre de mutagenese, deux experiences ont ete realisees dans deux contextes genetiques differents: male et femelle. Dans le contexte genetique male, les mutants obtenus (28 w et 4 v) correspondent a des deletions intralocus (de 4 a 109 nucleotides). Dans le contexte genetique femelle, sur 42 mutants w, 24 sont dus a des deletions intralocus (de 1 a 353 paires de bases), 18 proviennent de deletions de grande taille pouvant etre estimee a plusieurs centaines de milliers de paires de bases. Le sequencage de deux jonctions issues de large deletions montre que des sequences caracteristiques de la recombinaison illegitime sont proches des points de cassure. L'analyse de la sequence des mutations intralocus suggerent que la plupart d'entre eux resultent d'evenements de recombinaison non homologue entre deux sequences repetees situees aux bornes de la deletion, l'une etant conservee au niveau de la nouvelle jonction. De plus, la comparaison de la nature des mutations intralocus entre les deux contextes genetiques montre que la presence de la sequence homologue n'a pas d'influence sur le spectre de mutagenese du cis-ddp. Cette etude indique que le spectre de mutagenese du cis-ddp, en majorite des deletions, dans un organisme entier est tres different de celui obtenu chez des procaryotes et des cellules d'eucaryotes en culture
5
ATMANI, LOUISA. "Effet des donneurs d'electrons sur la fluorescence et l'isomerisation photochimiquetrans--cis et cis--trans des n, n'-diacylindigos." Paris 6, 1989. http://www.theses.fr/1989PA066015.
6
Le, Tulzo Harold. "Exploration de procédés tout-ALD via la synthèse de couches minces à base de sulfures et d’oxydes pour l’élaboration de cellules photovoltaïques de type CIGS." Electronic Thesis or Diss., Paris Sciences et Lettres (ComUE), 2018. http://www.theses.fr/2018PSLEC011.
Abstract:
Ce projet s’inscrit dans le champ thématique «Production durable et énergies renouvelables » de l’ADEME et plus particulièrement dans l’axe « Production, gestion et stockage de vecteurs énergétiques issus de sources renouvelables ». Il est proposé d’utiliser les atouts de la technique de dépôt chimique en phase vapeur par flux alternés (ALD) pour la synthèse de matériaux de haute qualité pour initier des transferts vers des procédés ALD optimisés pour l’industrialisation ainsi que permettre l’élaboration de cellules tout-ALD. Soucieux de comprendre les mécanismes de croissance impliqués, faire avancer les connaissances fondamentales liées à l’ALD et afin d’optimiser au mieux le matériau au dispositif, ce projet possède également un fort caractère exploratoire. Il s’inscrit dans les grands projets de recherches communs de l’IPVF (projet II.B en particulier), et profitera directement des ressources et compétences de l’IRDEP. L’objectif de cette thèse est d’utiliser les atouts de la technique ALD pour la synthèse de matériaux pour applications dans les futures générations de cellules solaires en couches minces CIGS. Cette technique permet le dépôt de films uniformes, couvrants et d’épaisseur contrôlée à l’échelle de la monocouche dans des conditions douces. Grâce à ses caractéristiques, elle connaît un développement spectaculaire dans le domaine industriel pour la microélectronique. Dans le domaine du photovoltaïque, le contrôle à une échelle de plus en plus précise des épaisseurs et des interfaces va également dans le sens d’une utilisation accrue de l’ALD dans les années à venir. Le cœur du projet portera sur la synthèse de matériaux et l’ingénierie fine des interfaces pour à la fois l’intégration dans des dispositifs CIGS, mais aussi l’élaboration de cellules tout-ALD. Le doctorant devra non seulement prendre en main un réacteur de dépôt ALD nouveau au laboratoire, mais surtout mettre à profit ses fonctionnalités pour la synthèse de matériaux par l’utilisation de précurseurs chimiques innovants. En parallèle, il utilisera un autre réacteur ALD équipé d’une assistance plasma qui permettra de diversifier les réactivités et le travail d’optimisation des interfaces. La compréhension des mécanismes réactionnels mises en jeu via des études in-situ (dont deux outils seront implémentés par le doctorant durant ce projet) et les caractérisations des matériaux synthétisés (DRX, MEB/EDX, transmission optique, ...) sera primordiale. En effet, cette dernière combinée à une stratégie adaptée de design des molécules permettront la synthèse de nouveaux matériaux de compositions et structures bien définies et des ingénieries d’interface à l’échelle de la monocouche atomique. Enfin, ces matériaux seront directement intégrés aux cellules CIGS, et testés pour valider les concepts et permettre le développement de dispositifs photovoltaïques plus performants et plus économes en matériau. Ils seront par ailleurs les composants fondamentaux d’une première cellule CIGS tout-ALDThe goal of this doctoral research project is to use the advantages of the ALD (Atomic Layer Deposition) technique for the synthesis of innovative materials to be used in the future generations of CIGS thin film solar cells. ALD technique allows the deposition in smooth conditions (low temperature, mbar pressure level) of conformal and uniform films, with a high control of the thickness at the atomic layer scale. Due its unique features, it is now widely applied in the field of microelectronics. In photovoltaics, the need to control at smaller scale and more accurately the thickness and the interfaces of the films implies a wide development of ALD in the next years. The main focus of this project is the synthesis of new materials with a fine interface engineering that will be integrated in CIGS devices and allows the elaboration of all-ALD solar cell. The doctoral candidate will pilot a new ALD reactor, and use its new functionalities to synthesize materials from innovative chemical precursors. In parallel, a second ALD reactor equipped with a plasma module will give access to other reactivities and allow further optimization of the interfaces. Understanding the reaction mechanisms involved via in-situ studies (for which two new analytical tools will be implemented by the student during the project) and materials characterization (XRD, SEM/EDX, optical transmission ...) will be compulsory for the success of this project. Finally, those materials will be integrated in CIGS devices, and tested to validate new concepts and allow the development of more efficient photovoltaic devices with reduced cost of atoms. In addition to this, they will be the building blocks of a first all-ALD solar cell
7
Dority, Tyler Maxwell. "The Effect of CIBS Participation and Gender on Adolescent Residential Treatment Duration." ScholarWorks, 2016. https://scholarworks.waldenu.edu/dissertations/2533.
Abstract:
Additional out-of-home placement rates for adolescents in long-term regional treatment center (LTRT) programs in the United States are between 50% and 75%. There appears to be a failure to generalize treatment to home and community in programs that do not fully integrate family involvement. The collaborative intensive bridging services (CIBS) treatment model uses intensive family therapy and brief residential treatment center (RTC) placement to reduce or eliminate use of LTRT. Using family systems theory, the purpose of this study was to determine whether participation in CIBS provided better outcomes than LTRT programs. The study used archival data collected by Family Adolescents and Children's Family Services, Inc. and children's mental health providers in a certain Minnesota county over approximately 5 years. There were 33 adolescents in the CIBS group and 33 in the LTRT group. The 3 research questions were (1) did the CIBS group have significantly fewer total out-of-home placements than the LTRT group, (2) did gender have any effect on this, and (3) were there any interaction effects on total out-of-home placement days from the combination of gender and program participation. Results of two-way ANOVA analyses showed a significant main effect for the first research question (p = .00, partial ɳ-² = .40), no significant main effect for the second (p = .46, partial ɳ-² = .01), and no significant main effect for the third (p = .15, partial ɳ-² = .03). These findings supported the position that participation in CIBS treatment resulted in statistically fewer total out-of-home placement days (TPD) than participation in LTRT. Social change implications include improved individual and family functioning for families in need as well as reduced financial expenditure for treatment.
8
Xiao, Meisheng [Verfasser]. "Dissecting cis-regulatory effect on alternative polyadenylation using hybrid mice / Meisheng Xiao." Berlin : Freie Universität Berlin, 2016. http://d-nb.info/1117541819/34.
9
Maclear, Athlee. "Identification of cis-elements and transacting factors involved in the abiotic stress responses of plants." Thesis, Rhodes University, 2005. http://hdl.handle.net/10962/d1007236.
Abstract:
Many stress situations limit plant growth, resulting in crop production difficulties. Population growth, limited availability and over-utilization of arable land, and intolerant crop species have resulted in tremendous strain being placed on agriculturalists to produce enough to sustain the world's population. An understanding of the principles involved in plant resistance to environmental stress will enable scientists to harness these mechanisms to create stress-tolerant crop species, thus increasing crop production, and enabling the farming of previously unproductive land. This research project uses computational and bioinformatics techniques to explore the promoter regions of genes, encoding proteins that are up- or down-regulated in response to specific abiotic stresses, with the aim of identifying common patterns in the cis-elements governing the regulation of these abiotic stress responsive genes. An initial dataset of fifty known genes encoding for proteins reported to be up- or down-regulated in response to plant stresses that result in water-deficit at the cellular level viz. drought, low temperature, and salinity, were identified, and a postgreSQL database created to store relevant information pertaining to these genes and the proteins encoded by them. The genomic DNA was obtained where possible, and the promoter and intron regions identified. The Neural Network Promoter Prediction (NNPP) software package was used to predict the transcription start signal (TSS) and the promoter searching software tool, TESS (Transcription Element Search Software) used to identify known and user-defined cis-elements within the promoter regions of these genes. Currently available promoter prediction software analysis tools are reported to predict one promoter per kilobase of DNA, whilst functional promoters are thought to only occur one in 30-40 kilobases, which indicates that a large perccntage of predictions are likely to be false positives (pedersen et. al., 1999). NNPP was chosen as it was rated as the highest performing promoter prediction software tool by Fickett and Hatzigeorgiou (1997) in a thorough review of eukaryotic promoter prediction algorithms, however results were less than promising as very few predicted TSS were identified in the area 50 bps up- and downstream of the gene start site, where biologically functional TSSs are known to occur (Reese, 2000; Fickett and Hatzigeorgiou, 1997). TESS results seemed to support the hypothesis that drought, low-temperature and high salinity plant stress response proteins have similar as-elements in their promoter regions, and suggested links to various other gene regulation mechanisms viz. gibberellin-, light-, auxin- and development-regulated gene expression, highlighting the vast complexity of plant stress response processes. Although far from conclusive, results provide a valuable basis for future comparative promoter studies that will attempt to deduce possible common transcriptional initiation of abiotic stress response genes.KMBT_363
Adobe Acrobat 9.54 Paper Capture Plug-in
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Duffett, Rodger Vincent. "The effect of cis-platinum alone or in combination with radiation on mouse lung." Master's thesis, University of Cape Town, 1999. http://hdl.handle.net/11427/26352.
Abstract:
Cis-platinum is a widely used cytotoxic agent with known radiosensitising properties. It is used in the treatment of various types of lung cancer that may include radiation to the lung as part of the treatment protocol. There is little evidence and some conflict as to whether it sensitises pulmonary tissue to the effects of radiation treatment. This project investigates the effect of cis-platinum alone or in combination with radiation on mouse lung. Four end points were used to evaluate treatments. They were: the release of pulmonary surfactant, changes in breathing rate, a histology based score of damage and changes in TGF-β - a cytokine important in the development of fibrosis. Single doses of either cis-platinum or radiation, cis-platinum given immediately before a single dose of radiation, cis-platinum given immediately before the first of two fractions of radiation and cis-platinum given at various times before and after a single dose of radiation were investigated. Cis-platinum alone was observed to cause an increase in the phospholipid content of lavaged surfactant. Cis-platinum was observed to cause an early release in surfactant and a trend existed for it to induce an early increase in breathing rates as compared to that induced by radiation alone. Cis-platinum was observed to increase radiation damage as assessed using a histology based scoring system. Higher TGF-β levels in lavaged surfactant were observed in C57 /Bl mice as compared to Balb/C. No difference in TGF-β levels was seen in homogenised lung between the strains. Cis-platinum may cause changes in TGF-β in C57/Bl mice but further work is necessary to confirm this.
11
Kulkarni, Sachin. "EFFECT OF COMPOSITION, MORPHOLOGY AND SEMICONDUCTING PROPERTIES ON THE EFFICIENCY OF CUIN1-XGAXSE2-YSY THIN-FILM SOLAR CELLS PRE." Doctoral diss., University of Central Florida, 2008. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/2938.
Abstract:
A rapid thermal processing (RTP) reactor for the preparation of graded CuIn1-xGaxSe2-ySy (CIGSeS) thin-film solar cells has been designed, assembled and is being used at the Photovoltaic Materials Laboratory of the Florida Solar Energy Center. CIGSeS films having the optimum composition, morphology, and semiconducting properties were prepared using RTP. Initially films having various Cu/(In+Ga) ratios were prepared. In the next step selenium incorporation in these films was optimized, followed by sulfur incorporation in the surface to increase the bandgap at the surface. The compositional gradient of sulfur was fine-tuned so as to increase the conversion efficiency. Materials properties of these films were characterized by optical microscopy, SEM, AFM, EDS, XRD, GIXRD, AES, and EPMA. The completed cells were extensively studied by electrical characterization. Current-voltage (I-V), external and internal quantum efficiency (EQE and IQE), capacitance-voltage (C-V), and light beam induced current (LBIC) analysis were carried out. Current Density (J)-Voltage (V) curves were obtained at different temperatures. The temperature dependence of the open circuit voltage and fill factor has been estimated. The bandgap value calculated from the intercept of the linear extrapolation was ~1.1-1.2 eV. Capacitance-voltage analysis gave a carrier density of ~4.0 x 1015 cm-3. Semiconductor properties analysis of CuIn1-xGaxSe2-ySy (CIGSeS) thin-film solar cells has been carried out. The values of various PV parameters determined using this analysis were as follows: shunt resistance (Rp) of ~510 Ohms-cm2 under illumination and ~1300 Ohms-cm2 in dark, series resistance (Rs) of ~0.8 Ohms-cm2 under illumination and ~1.7 Ohms-cm2 in dark, diode quality factor (A) of 1.87, and reverse saturation current density (Jo) of 1.5 x 10-7A cm-2. The efficiency of 12.78% obtained during this research is the highest efficiency obtained by any University or National Lab for copper chalcopyrite solar cells prepared by RTP. CIGS2 cells have a better match to the solar spectrum due to their comparatively higher band-gap as compared to CIGS cells. However, they are presently limited to efficiencies below 13% which is considerably lower than that of CIGS cells of 19.9%. One of the reasons for this lower efficiency is the conduction band offset between the CIGS2 absorber layer and the CdS heterojunction partner layer. The band offset value between CIGS2 and CdS was estimated by a combination of ultraviolet photoelectron spectroscopy (UPS) and Inverse Photoemission Spectroscopy (IPES) to be -0.45 eV, i.e. a cliff is present between these two layers, enhancing the recombination at the junction, this limits the efficiency of CIGS2 wide-gap chalcopyrite solar cells.Ph.D.
Department of Mechanical, Materials and Aerospace Engineering
Engineering and Computer Science
Materials Science & Engr PhD
12
Gerthoffer, Arnaud. "Propriétés mécaniques des cellules photovoltaïques à base de CIGS sur substrats en verre ultra-fin." Thesis, Université Grenoble Alpes (ComUE), 2016. http://www.theses.fr/2016GREAI077/document.
Abstract:
L’objectif de ces travaux est d’étudier et de développer des cellules solaires à base de couches minces de CIGS élaborées sur un substrat innovant : le verre ultra-fin. Ce matériau possède des propriétés avantageuses, liées notamment à sa résistance aux températures élevées, à sa légèreté, à son aptitude à bloquer l’humidité, à sa transparence et à une certaine flexibilité mécanique. Nous avons ici cherché à exploiter ces propriétés pour la fabrication de cellules CIGS légères et conformables. D’abord, nous montrons la faisabilité de cellules CIGS sur des substrats en verre ultra-fin de 100 mm d’épaisseur. Nous obtenons un rendement de 12,1 % en utilisant une électrode arrière en bicouche composée d’une couche de Mo pure et d’une couche contenant du sodium, ce qui constitue le record actuel pour la technologie CIGS sur verre ultra-fin. Nous montrons ensuite que les performances des cellules peuvent se détériorer sous l’effet de flexions mécaniques répétées avec un rayon de courbure de 5 cm, en partie en raison de la formation de fissures dans les cellules. Nous présentons ensuite une étude sur les propriétés mécaniques du Mo et du CIGS, réalisée à partir d’essais de nanoindentation. La dureté et le module de Young de ces deux couches sont reportés ainsi que, pour la première fois, la ténacité et les contraintes résiduelles du CIGS. Ces résultats sont ensuite utilisés pour calculer les contraintes générées dans le CIGS lors de la flexion des cellules. Enfin, nous proposons une structure bi-verre optimisée pour limiter les contraintes dans le CIGS en flexionThe goal of this work is to study and to develop CIGS thin-film solar cells on an innovative substrate: the ultra-thin glass. This material has advantageous properties, mainly attributed to its high temperature resistance, its lightweight, its barrier property against moisture, its transparency and its mechanical flexibility. Here we tried to use these properties for the fabrication of lightweight and conformable CIGS solar cells. First, we demonstrate the feasibility of CIGS solar cells on 100 mm-thick ultra-thin glass substrates. We reached 12.1 % efficiency by using a bilayer back contact consisting of a pure Mo layer and a sodium doped Mo layer, which is up to now the record efficiency for CIGS solar cells on ultra-thin glass substrate. Then we show that solar cell performances can deteriorate under cyclic bending fatigue conditions with a radius of curvature of 5 cm. This is partially explained by the formation of cracks in the cells. Then, we report on the mechanical properties of the Mo and the CIGS layers measured by nanoindentation. The hardness and the Young’s modulus of each layer is given and, for the first time, the toughness and the residual stresses of the CIGS. These results are then used to calculate the CIGS internal stresses when the cells are bent. Finaly, we propose a glass-glass structure optimized to lower the CIGS internal stresses under bending
13
Roger, Charles. "Developpement de cellules photovoltaïques à base de CIGS sur substrats métalliques." Phd thesis, Université de Grenoble, 2013. http://tel.archives-ouvertes.fr/tel-00965592.
Abstract:
Ces travaux de thèse ont pour but de développer des cellules photovoltaïques à base de Cu(In,Ga)Se2 (CIGS) sur des substrats métalliques. L'objectif principal consiste à résoudre les différentes problématiques liées à l'utilisation de ces substrats (Ti et acier inoxydable) en s'appuyant sur une adaptation de l'électrode arrière. L'étude est focalisée sur l'élaboration de contacts arrière en Mo par pulvérisation cathodique. Dans un premier temps, des contacts arrières en monocouches et en bicouches sont comparés, démontrant les intérêts des structures en bicouches. Ces dernières sont obtenues en utilisant successivement deux pressions différentes pendant le dépôt du contact arrière. Nous montrons que la pression utilisée pendant le dépôt de la couche inférieure influe sur la morphologie de la couche supérieure. Il en résulte des modifications de l'orientation cristalline du CIGS et des performances photovoltaïques. Dans une seconde étude, la couche inférieure est déposée à partir d'une cible de molybdène contenant du sodium (Mo:Na) afin d'apporter du Na dans le CIGS. Les différences entre le Mo et le Mo:Na sont d'abord étudiées. Nous montrons ensuite que la diffusion du sodium vers le CIGS dépend de la pression de dépôt de la couche de Mo:Na. Dans le cas de substrats en Ti, des rendements équivalents aux substrats en verre sodo-calcique sont obtenus en utilisant le molybdène dopé au sodium. Nous montrons aussi qu'en présence de sodium, l'effet de la pression de dépôt de la couche inférieure sur les performances est minimisé.
14
Chandrasekaran, Vinodh. "Effect of heat treatments and reduced absorber layer thickness on cu(in,ga)se2 thin film solar cells." [Tampa, Fla.] : University of South Florida, 2005. http://purl.fcla.edu/fcla/etd/SFE0001316.
15
Anin, Marie-France. "Deformations de l'adn par les adduits du cis-platine : effets sur la transcription et la replication." Orléans, 1992. http://www.theses.fr/1992ORLE2002.
Abstract:
Nous avons caracterise la deformation de la double helice d'adn engendree par l'adduit bifonctionnel cis-pt(nh#3)#2d(gtg) et de l'adduit trans-pt(nh#3)#2d(gtg). Dans les deux cas, une courbure de l'axe de la double helice d'adn est observee, qui se traduit par le desappariement de deux paires de bases (cis-ddp) ou quatre paires de bases (trans-ddp) avec expulsion de la thymine centrale de l'adduit. Nous avons cherche a correler le role des deformations induites par les adduits du cis-ddp avec differents processus cellulaires comme la replication de la transcription. Nous montrons que l'adduit cis-pt(nh#3)#2d(gg) et l'adduit cis-pt(nh#3)#2d(ag) inhibent la transcription in vitro. Cependant, il est observe un effet inhibiteur plus important pour l'adduit cis-pt(nh#3)#2d(gg) qui est relie a la deformation de la double helice d'adn induite par cet adduit. L'etude de la reaction du derive monofonctionnel du cis-ddp: le cis-pt(nh#3)#2(me-dap)cl#2#+ avec l'adn naturel a confirme que l'adduit forme dans l'adn double brin est instable, avec liberation de cis-pt(nh#3)#2(medap)cl#2#+ et/ou de medap. Cette instabilite a ete mise en evidence par des experiences de replication in vitro qui ont montre que les adduits monofonctionnels du cis-pt(nh#3)#2(medap)cl#2#+ inhibent la replication in vitro. La deformation locale de la double helice semble jouer un role important dans le phenomene d'instabilite des adduits du cis-pt(nh#3)#2(me-dap)cl#2#+. D'autre part, nous montrons que les adduits du cis-pt(nh#3)#2(me-dap)cl#2#+ sur l'adn n'arretent pas l'arn polymerase; au cours du temps, le profil d'arrets de l'arn polymerase qui apparait correspond a celui obtenu avec l'adn modifie par le cis-ddp, ce qui implique la liberation de medap
16
Petit, Jean-Marie. "Effet hypnogène de l'acide 13-cis-rétinoïque chez le rat : arguments en faveur de l'implication du VIP : approches polygraphique, immunohistochimique et biochimique." Lyon 1, 1995. http://www.theses.fr/1995LYO1T207.
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Hansson, Henrik. "Understanding interfaces in thin-film solar cells using photo electron spectroscopy. : Effect of post-deposition treatment on composition of the solar cell absorber." Thesis, Uppsala universitet, Institutionen för fysik och astronomi, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-399623.
Abstract:
The increasing demand of renewable energy is the big driving force for the research and development of more efficient solar energy conversion solutions. Solar cells, which use the photovoltaic effect to convert the photon energy to electrical current, are an important solar energy conversion technique. One solar cell technology is thin-film solar cells. Thin-film solar cells use an absorption layer with a direct band gap. A direct band gap has the advantage that the photons will penetrate less deep until a photoexcitation occur compared to semiconductors with an indirect band gap (e.g. silicon). For this reason the thin-film solar cells can be made very thin.CIGS is a common thin-film solar cell absorber material containing copper (Cu), indium (In), gallium (Ga) and selenium (Se). One objective of this work has been to determine element concentrations of CIGS absorption layers from sample measurements. The GGI ratio determines the band gap, which is an important factor for optimising the efficiency of the solar cell.1 The copper vacancy is the main acceptor dopant in CIGS. The Cu concentration has shown to be important for the efficiency and for other properties of the absorber [2].The measuring technique used in this work has been photoelectron spectroscopy (PES). PES produces a spectrum showing distinct peaks corresponding to electron binding energy levels for specific element subshells. Measurements with different photon energies have been performed on samples with and without post deposition treatment (PDT). A great deal of the effort has been to calculate relative element concentrations based on the PES peak intensities. Two important parameters when performing the calculations are the photoionization cross section (including the angular dependence of the cross section) and the inelastic mean free path of the photoelectrons.The results show that the GGI and the corresponding band gap will be almost the same with and without PDT except for close to the surface where PDT lowers the GGI.The calculations showed that the copper concentration is lowest at the surface. Moreover, PDT with RbF results in lower copper concentration closer to the junction.The results show a discrepancy of the GGI and CGI ratios when using the angular dependent cross sections in [10] and [11] compared to using the cross sections in [6] and [7].Det ökande behovet av förnybar energi gör att forskning och utveckling av solenergilösningar är av största vikt. Solceller, vilka utnyttjar den fotovoltaiska effekten, är den vanligaste tekniken för omvandling av solenergi till elektricitet. Tunnfilmssolceller är en typ av solceller vars absorbent har ett direkt bandgap, till skillnad från kisel som har ett indirekt bandgap. Fördelen med ett direkt bandgap är att det ljusabsorberande materialet kan göras mycket tunt.En vanlig tunnfilmssolcell är CIGS. Det är en komposit bestående av koppar (Cu), indium (In), gallium (Ga) och selen (Se). Ett syfte med detta självständiga arbete har varit att beräkna koncentrationerna av de ingående ämnena i halvledarskiktet av CIGS. GGI-kvoten bestämmer bandgapet, vilket är en viktig faktor för solcellens verkningsgrad. Kopparvakansen är den huvudsakliga halvledaracceptorn i CIGS. Kopparkoncentrationen har visat sig vara viktig för bl.a. solcellens verkningsgrad [2].Mättekniken som används i detta arbete kallas fotoelektronspektroskopi (PES). PES-mätningar ger ett spektrum där spektrallinjerna representerar olika nivåer av elektroners bindningsenergi för olika grundämnen. Mätningar med olika fotonenergier, på prover med och utan ytbehandling (PDT), har utförts. En stor del av arbetet har varit att beräkna relativa koncentrationer av de olika grundämnena från spektrallinjerna i spektrumet. Viktiga parametrar som man behöver ta hänsyn till i uträkningarna är sannolikheten för en fotoemissionsprocess hos fotonerna, vinkelberoendet och den fria medelväglängden hos fotoelektronerna.Resultaten visar att GGI-kvot och bandgap blir nästan detsamma med eller utan PDT, förutom närmast ytan där PDT minskar GGI-kvoten.Resultaten visar också att kopparkoncentrationen är lägst på ytan och att PDT med RbF minskar kopparkoncentrationen närmast ytan.Resultaten visar att det blir skillnader mellan GGI- och CGI-kvoterna beroende på om beräkningarna baserats på vinkelberoende träffytor enligt [10] och [11] eller baserats på träffytor enligt [6] och [7].
18
Mata, Xavier. "Analyse structurale et fonctionnelle de gènes voisins du "locus" de l'α-lactalbumine caprine : application à la recherche d'éléments "cis"-régulateurs à effet dominant." Limoges, 2003. http://www.theses.fr/2003LIMO0033.
Abstract:
L'utilisation récente de grands fragments d'ADN (BACs et YACs) a permis de s'affranchir de " l' effet de position "en transgénèse. Cela a été le cas pour un BAC caprin de 160 kb contenant le gène de l'a-lactalbumine (BAC 41), suggérant la présence d'éléments cis-régulateurs dominants. Mon sujet de thèse visait à analyser plus finement cet insert. Des expériences de transgénèse utilisant un BAC raccourci dérivé (BAC 6) nous a permis d'effectuer une primo-localisation de ces éléments. Dans cette région deux loci ont été identifiés : celui de la cycline T1 et FLJ20436. Leur caractérisation fonctionnelle a permis de montrer qu'ils sont actifs au sein du BAC et à expression ubiquiste. De façon inattendue, l'utilisation du promoteur de la cycline T1 en transgénèse a conduit à unessur-expression dans la lignée germinale mâle. Le gène FLJ20436 présente un épissage complexe. Ces études nous ont amenés à suspecter la présence de deux domaines chromatiniens putatifs séparant ces gènes à expression ubiquiste de celui de l'a-lactalbumine. L'analyse structurale de ces loci a permis de dresser une carte précise du BAC 41 et de délimiter une région frontière séparant les deux domaines chromatiniens putatifs. Une recherche en son sein d'éléments cis-régulateurs dominants a été initiée. L'identification et l'association de tels éléments au promoteur du gène de l'a-lactalbumine devraient contribuer à la mise au point de vecteurs d'expression efficients pour la transgénèse mammaireThe recent use of large genomic fragment (BACs or YACs) has allowed to avoid this "position effect". This has been observed with a vector that was developed in our laboratory that consists of a 160 kb goat BAC insert (BAC 41) encompassing the a-lactalbumin gene, suggesting the occurrence of dominant cis-regulatory elements. The aim of this thesis was to further analyse this insert. Transgenic experiments using a derived shorter BAC of 60 kb allowed us to localise these regulatory elements in a 5' distal region of the a-lactalbumin locus. In this region two loci were identified: the cyclin T1 and FLJ20436. Characterisation of these genes revealed that they were functional within the BAC 41 and ubiquitously expressed. Surprisingly, the use of the cyclin T1 promoter in transgenics resulted in an ubiquitous expression unexpectedly high only in male germ cells. FLJ20436 pre-mRNA has a very complex splicing pattern that is conserved during evolution. These observations led us to suspect the occurrence of two chromatin domains separating these ubiquitously expressed genes from the a-lactalbumin one. Structural analysis of these genes has allowed to define a precise restriction map of the BAC 41 and to precise the location of the potential border region within the two chromatin domains. Search for cis-regulatory elements within this region was initiated. There identification and association with the a-lactalbumin promoter should contribute to the creation of efficient mammary specific expression vectors
19
Lapeyre, Pascale. "Nouveaux aspects anatomo-fonctionnels des cellules ciliées vestibulaires de type 1 : morphologie des touffes ciliaires, motilité cellulaire réversible et modulation GABAergique de l'excitabilité des cellules de type 1 du cobaye." Bordeaux 2, 1992. http://www.theses.fr/1992BOR28206.
20
Matinyenya, Patience. "South frica’s non-ratification of the United Nations convention on Contracts for the International Sale of Goods (CISG), wisdom or folly, considering the effect of the status quo on international trade." University of the Western Cape, 2011. http://hdl.handle.net/11394/2926.
Abstract:
Magister Legum - LLMThe United Nations Convention on Contracts for the International Sale of Goods 1980 (CISG) seeks to provide a standard uniform law for international sales contracts. This research paper analyses the rationale behind South Africa’s delay in deciding whether to ratify the CISG, and its possible effect on trade with other nations. The CISG drafters hoped that uniformity would remove barriers to international sales thereby facilitating international trade. Ratification of the convention is only the beginning of uniformity; uniformity must then be extended to its application and interpretation. Not all countries have ratified the Convention yet they engage in international trade in goods: this state of affairs presents challenges since traders have to choose a national law that applies to their contract where CISG does not apply. This takes traders back to the undesirable pre-CISG era. On the other hand, those States that have ratified the convention face different challenges, the biggest one being a lack of uniformity in its interpretation. The problem of differing interpretations arises because some CISG Articles are vague leading to varied interpretations by national courts. Further, the CISG is still largely misunderstood and some traders from States that have ratified CISG exclude it from application. South Africa can only ratify an international instrument such as the CISG, after it has been tabled before Parliament, and debated upon in accordance with the Constitution. CISG’s shortcomings, particularly regarding interpretation, make it far from certain that CISG would pass the rigorous legislative process. Nonetheless, the Constitution of South Africa requires the South African courts and legislature to promote principles of international law. The paper, therefore, examines, whether the Legislature has a constitutional obligation to ratify CISG. South Africa’s membership of the WTO requires that it promote international trade by removing trade barriers. It is, therefore, vital for South Africa to be seen to be actively facilitating international trade. Even though the trade benefits which flow from ratification are not always visible in States that have ratified the CISG, there is some doubt whether South Africa can sustain its trade relations without ratifying the CISG. The paper shows that the formation of contracts under the South African common law is very similar to formation as set out under Part II of the CISG and if the CISG were to be adopted in South Africa, no major changes would be needed in this regard. International commercial principles as an alternative to the CISG still require a domestic law to govern the contract and would, therefore, leave South African traders in the same position they are in currently, where their trading relations are often governed by foreign laws. Ratifying CISG would certainly simplify contract negotiations particularly with regard to governing law provisions. Overall the advantages of ratification for South Africa far outweigh the shortcomings of the CISG, and ratification will assist in ensuring that South African traders get an opportunity to enter the international trade arena on an equal platform with traders from other nations.
South Africa
21
Espagne, Agathe. "Photoisomérisation ultrarapide du chromophore et de la protéine jaune photoactive : effets de structure et d' environnement." Paris 6, 2005. http://www.theses.fr/2005PA066500.
22
Lavoie, Monique V. "Characterisation of a conserved motif found within the Dlx cis-regulatory element URE2 and its effect on mouse URE2-lacZ activity in transgenic mice." Thesis, University of Ottawa (Canada), 2010. http://hdl.handle.net/10393/28433.
Abstract:
The Distal-less-like genes, commonly referred to as Dlx genes, encode homeodomain transcription factors essential for the establishment of GABAergic interneurons in the ventral forebrain as well as their migration to the cortex. The cis-regulatory element URE2 (enhancer) is located upstream of Dlx1 and is thought to regulate the transcription of Dlx1 and/or Dlx2. The objective of this study was to examine a short conserved sequence within the URE2 element, corresponding to nucleotides 699-719, and to evaluate its contribution to URE2 activity in transgenic mouse forebrain. My results showed that a mutant version of the URE2 element, in which nucleotides 699-719 were modified, was active in the cortex and the ventricular zone of forebrain of the transgenic mice produced with the mutant enhancer, where Dlx1/Dlx2 are not usually expressed. This indicated a loss of binding by a protein with a transcriptional repressor function. Previous analyses suggested that mURE2nt699-719 would be a good candidate for a REST repressor binding site. However, we were not able to observe any transcriptional regulation by REST in co-transfection experiments performed in cultured cells. This, as well as revised bioinformatical information, led us to identify four new candidates possibly using mURE2nt699-719 as a binding site, namely the Nuclear- Factor-1 proteins: NFIA, NFIB, NFIC and NFIX. These genes are associated with transcriptional regulation, being repressors and/or activators of gene expression in the brain. We showed that NFIC was able to utilize the mURE2nt699-719 sequence to reduce the luciferase reporter expression in neuronal cells, which would explain the loss of repression in our transgenic mice at embryonic days E11.5 and E13.5. These preliminary results also allowed us to suggest that a heterodimer between NFIC/NFIB and NFIC/NFIX binds to the mURE2699-719 sequence at embryonic day E15.5 and postnatal day 0 (P0) of the transgenic mice since the mutated enhancer's activity seems to indicate a loss of an activator at those stages. These results suggest that these factors could possibly be required for the regulation of the Dlx genes by URE2. These results will also help clarify the role of URE2 by identifying transcription factors that contribute to the genetic program involved in the cellular organization of the developing forebrain in vertebrates.
23
Honorato, Sara Braga. "Antioxidant effect of components of the latex from seringueira (Hevea brasiliensis)and mangabeira(Hancoria speciosa)on thermo-oxidative degradatiion of synthesic Poly (1,4-cis-isoprene." Universidade Federal do CearÃ, 2005. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=1429.
Abstract:
FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgicoFundaÃÃo de Amparo à Pesquisa do Estado do CearÃ
Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico
This work is divided into two parts: The first is associated with the isolation of non-isoprenic components from the natural rubber (NR) latex from seringueira (Hevea brasiliensis) and mangabeira (Hancornia speciosa) by centrifugation. In the first centrifugation the phase serum was isolated (MAT 1). The rubber phase was treated with the surfactant sodium dodecyl sulphate (SDS) and isolated after the third centrifugation (MAT 2). The other materials tested in the synthetic rubber (PIS) were CENT 1, CENT 2 and the NR extract. These were kindly provided by Prof Jean Marinho from UNESP. The second part is associated with the possible antioxidant effect of the isolated latex components on the thermo-oxidative degradation of synthetic poly(1,4-cis-isoprene) carried out via infrared (FT-IR), thermogravimetric analysis (TG) and Nuclear Magnetic Resonance (RMN). It was observed that, from the substances obtained from the purification of the latex and tested on synthetic PIS, both MAT 1 and CENT 1 have pro-oxidant effects. The remain can be ordered in the following sequence in regards to their antioxidant capabilities: PIS + MAT 2 > PIS + NR EXTRACT > PIS + CENT 2 The calculation of the activation energy of the thermal degradation of PIS in synthetic air containing 2.0% of MAT 2 confirms that the stabilizer effect of PIS increases with the increase of this material, as all Ea of pure polymer are inferior to that of the doped sample. The NMR spectra for MAT 2 showed, in addition to the characteristic bands of cis-1,4-polyisoprene, also bands associated with fatty acids and/or SDS. The spectra of NR extract showed bands that are characteristic of oligosaccharides and minoritary cis-1,4-polyisoprene.
O presente trabalho à dividido em duas partes: A primeira està relacionada com o isolamento dos componentes nÃo-isoprÃnicos do lÃtex da borracha natural (BN) da seringueira (Hevea brasiliensis) e mangabeira (Hancornia speciosa) por centrifugaÃÃo. Na primeira centrifugaÃÃo foi isolada a fase serum (MAT 1). A fase borracha foi tratada com o surfactante dodecil sulfato de sÃdio (SDS) e isolada apÃs a terceira centrifugaÃÃo, (MAT 2). Os outros materiais testados à borracha sintÃtica (PIS) foram o CENT 1, CENT 2 e o extrato de BN, os quais foram gentilmente cedidos pelo Prof. Jean Marinho da UNESP. A segunda parte refere-se ao possÃvel efeito antioxidante dos componentes do lÃtex isolados sobre a degradaÃÃo termo-oxidativa do poli (1,4-cis-isopreno) sintÃtico realizada atravÃs das tÃcnicas de Infravermelho (FT-IR), AnÃlise TermogravimÃtrica (TG) e RessonÃncia MagnÃtica Nuclear (RMN). Foi observado que, das substÃncias obtidas da purificaÃÃo do lÃtex e testadas no PIS sintÃtico, tanto o MAT 1 quanto o CENT 1 tÃm efeitos prÃ-oxidantes. Os demais podem ser ordenados na seguinte seqÃÃncia quanto ao poder antioxidante: PIS + MAT 2 > PIS + EXTRATO DE BN > PIS + CENT 2 O cÃlculo da energia de ativaÃÃo (Ea) da degradaÃÃo tÃrmica do PIS em ar sintÃtico contendo 2,0% do MAT 2 confirma que o acrÃscimo desse material exerce um efeito estabilizante ao PIS, pois todas as Ea do polÃmero puro sÃo inferiores à da amostra dopada. Os espectros de RessonÃncia MagnÃtica Nuclear para o MAT 2 exibiram, alÃm de sinais caracterÃsticos do cis-1,4-poliisopreno, sinais relativos a Ãcidos graxos e/ou SDS, enquanto que os espectros do Extrato de BN exibiram sinais caracterÃsticos de oligossacarÃdeos e poli (1,4-cis-isopreno) como componentes minoritÃrios.
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PEREZ, CECILE. "Structure, stabilite et effets sur la replication in vitro des pontages interbrins formes dans la reaction entre la drogue antitumorale cis-dichlorodiammineplatine(ii) et l'adn." Orléans, 1997. http://www.theses.fr/1997ORLE2022.
Abstract:
En se fixant sur l'adn, la drogue antitumorale cis-dichlorodiammineplatine(ii) (cis-platine) forme des adduits intrabrins majoritaires dans les sites d(gg), d(ag). Nous avons etudie les adduits interbrins minoritaires formes dans le site d(gc/gc) par des techniques physicochimiques et biochimiques. Premierement, nous avons defini la structure de l'adn en presence de l'adduit interbrin. Les deformations (courbure de 45 et deroulement de 79) de l'adn induites par l'adduit interbrin du cis-platine ont ete determinees par des techniques physicochimiques. Ces deformations sont independantes de la nature des paires de bases adjacentes au site d(gc/gc). Les deformations prononcees de l'adn, notamment le deroulement ont necessite l'utilisation de la resonance magnetique nucleaire et de la modelisation moleculaire pour obtenir la structure en solution de l'adduit interbrin. L'adn modifie par l'adduit interbrin presente une mini double helice gauche au niveau du site d(gc/gc). Le pontage par le platine des atomes n7 des guanines platinees initialement positionnees dans le grand sillon de l'adn b provoque le retournement des guanosines de 180. Le groupement cis-diammineplatine(ii) se positionne alors dans le petit sillon de l'adn. Il est admis que les adduits bifonctionnels dont les pontages interbrins sont stables dans les conditions physiologiques. Pourtant nous avons observe que le pontage interbrin du cis-platine est instable a 37c. Les liaisons entre le platine et l'atome n7 des guanimes platinees sont rompues. Le clivage des adduits interbrins donne des adduits monofonctionnels sur les deux brins d'adn qui se rearrangent en adduits intrabrins. Enfin, l'etude de la replication in vitro avec des adn polymerases procaryotes de l'adn modifie par un pontage interbrin unique montre qu'il entraine une arret franc de la replication. La structure particuliere de l'adduit interbrin n'est pas conservee en presence du brin neosynthetise par les polymerases. L'absence de la structure de l'adduit interbrin conduit a stabiliser fortement le pontage interbrin du cis-platine.
25
Bretherton, Nicola. "The effect of cis-5,8,11,14,17-eicosapentaenoic acid upon the contractile mechanisms linked to calcium influx and the mobilisation of intracellular calcium in aortic smooth muscle." Thesis, Aston University, 1998. http://publications.aston.ac.uk/10988/.
Abstract:
Epidemiological studies previously identified cis-5,8,11,14,17-eicosapentaenoic acid (EPA) as the biologically active component of fish oil of benefit to the cardiovascular system. Although clinical investigations demonstrated its usefulness in surgical procedures, its mechanism of action still remained unclear. It was shown in this thesis, that EPA partially blocked the contraction of aortic smooth muscle cells to the vasoactive agents KCl and noradrenaline. The latter effect was likely caused by reducing calcium influx through receptor-operated channels, supporting a recent suggestion by Asano et al (1997). Consistently, EPA decreased noradrenaline-induced contractures in aortic tissue, in support of previous reports (Engler, 1992b). The observed effect of EPA on cell contractions to KCl was not simple due to blocking calcium influx through L-type channels, consistent with a previous suggestion by Hallaq et al (1992). Moreover, EPA caused a transient increase in [Ca2+]i in the absence of extracellular calcium. To resolve this it was shown that EPA increased inositol phosphate formation which, it is suggested, caused the release of calcium from an inositol phosphate-dependent internal binding site, possibly that of an intracellular membrane or superficial sarcoplasmic reticulum, producing the transient increase in [Ca2+]i. As it was shown that the cellular contractile filaments were not desensitised to calcium by EPA, it is suggested that the transient increase in [Ca2+]i subsequently blocks further cell contraction to KCl by activating membrane-associated potassium channels. Activation of potassium channels induces the cellular efflux of potassium ions, thereby hyperpolarising the plasma membrane and moving the membrane potential farther from the activation range for calcium channels. This would prevent calcium influx in the longer term and could explain the initial observed effect of EPA to block cell contraction to KCl.
26
Betz, Helene [Verfasser], and Sebastian [Akademischer Betreuer] Sauerbier. "Effekt von Trans-8-tert-butyl-GABA-Pentin-Lactam und Cis-8-tert-butyl-GABA-Pentin-Lactam auf das Proliferations-und Differenzierungsverhalten von humanen mesenchymalen Stammzellen." Freiburg : Universität, 2013. http://d-nb.info/1123475741/34.
27
Muller, Fabrice. "Mémoire présenté en vue de l'obtention de L'Habilitation à Diriger des Recherches." Habilitation à diriger des recherches, Université d'Orléans, 2004. http://tel.archives-ouvertes.fr/tel-00067858.
Abstract:
L'étude des propriétés des minéraux argileux et en particulier des phyllosilicates 2:1 dioctaédriques nécessite une analyse à différentes échelles de leurs caractéristiques. Les résultats exposés concernent l'échelle locale (organisation structurale interne du feuillet, interaction cation - feuillet) et semi-locale (nature des empilements). Dans un premier temps sont présentés des travaux centrés sur les relations d'ordre-désordre dans l'organisation des cations octaédriques majeurs (Al, Fe, Mg). La distribution des cations n'est pas aléatoire mais structurée en domaines qui peuvent être monocationiques (Fe ou Al) ou de composition cationique mixte. Dans ce dernier cas, la tendance est à l'homogénéisation des déficits de charges. Dans un second temps sont étudiées des transformations structurales induites par des traitements thermiques (déshydroxylation) et hydrothermaux (réhydroxylation). Des modèles de migration cationique à l'intérieur des couches octaédriques sont proposés pour expliquer les évolutions de structure. La composition et la distribution cationique des couches octaédriques jouent un rôle primordial dans les processus. Les traitements sont responsables, dans le cas des smectites, d'une augmentation du désordre dans la distribution des feuillets à différentes couches d'eau et d'une diminution des propriétés d'hydratation pour certains feuillets.
Les projets en cours, sur les interactions molécules organiques - argiles, sont présentés dans une dernière partie. Les aspects structuraux sont principalement développés (organisation de l'espace interfoliaire, rôle sur l'organisation micro-texturale de la phase argileuse).
28
Donaldson, Kathryn Marie. "Relationships between chromosome structure and long distance regulation of gene expression : a study of cis and trans modifiers of terminal deficiency-associated position effect variegation in a Drosophila melanogastor minichromosome /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2000. http://wwwlib.umi.com/cr/ucsd/fullcit?p9987530.
29
Blanchet, Christophe. "Caractérisation de la réponse cholinergique des cellules ciliées externes cochléaires." Bordeaux 2, 1997. http://www.theses.fr/1997BOR28490.
30
Lee, Heekyoung Verfasser], Johann Josef [Akademischer Betreuer] [Gutachter] Hauner, and de Angelis Martin [Gutachter] [Hrabé. "Understanding the molecular mechanism underlying the effect of cis-regulatory variants on gene expression at T2D associated loci / Heekyoung Lee ; Gutachter: Martin Hrabé de Angelis, Johann Josef Hauner ; Betreuer: Johann Josef Hauner." München : Universitätsbibliothek der TU München, 2016. http://d-nb.info/1135724830/34.
31
Zervos, Michel. "Réactivité des aminonitriles vis à vis des cyclénones et comparaison avec celle des éthers de cyanhydrines : stéréochimie et conformation des cyclanones 2,3 disubstituées." Paris 11, 1986. http://www.theses.fr/1986PA112007.
Abstract:
Cette thèse décrit l'addition conjuguée des dérivés lithiés équivalents d'acyle tels que les éthers de cyanhydrines et les aminonitriles aux α-cyclénones diversement substituées suivie de la protonation des énolates formés. L'action des équivalents de benzoyle sur les α-cyclénones α-substituées conduit aux adduits 1,4 de stéréochimie cis. D'autre part, contrairement aux éthers de cyanhydrines, les aminonitriles ne réagissent pas avec des α-cyclénones β-substituées. Par contre, en présence d'acides de Lewis leur réactivité vis à vis d'αénones encombrées est largement augmentée. Le piégeage des énolates formés par différents électrophiles a été aussi examiné. Dans le cas des éthers de cyanhydrines l'alkylation par l'iodure de méthyle conduit aux adduits trans quelle que soit la taille du cycle. Par contre, avec les aminonitriles cette réaction est limitée à la série cyclopentanique. Néanmoins avec un électrophile très réactif tel que le bromacétate d'éthyle on obtient des cyclohexanones 2,3 disubstituées trans. Contrairement aux aminonitriles équivalents de formyle ceux d'acétyle réagissent vis à vis des α-cyclénones α-substituées d'une manière comparable à celle des équivalents de benzoyle. Dans tous les cas les acyl-3 cyclanones substituées en position 2 ont été obtenues avec conservation de la stéréochimie cis ou trans des adduits de départ sauf en série cyclopentanique. L'étude conformationnelle par H RMN 2D des sélénophényl-2 cyclo hexanones 3-substituées a révélé une préférence du groupe PhSe pour la position axiale. Une stabilisation résultant d'un recouvrement des orbitales σ* de la liaison C-SePh et des orbitales π du carbonyle a été proposéeThe present work describes the conjugate addition of latent acyl anion equivalents such as protected cyanohydrines and N-dialkyl aminonitriles to cyclic α,β unsaturated enones diversely substituted followed by protonation of the intermediate formed enolates. The reaction of benzoyl equivalents on α-substituted α-cyclénones leads to 1,4 adducts possessing a cis stereochemistry. The aminonitriles don't react with the β,β-disubstituted α-enones and these results are in contradiction with the literature data concerning similar reactions with the corresponding cyanohydrin ethers. Nevertheless, their reactivity towards sterically hindered α-enones is largely increased in the presence of Lewis acids. The trapping of the intermediate enolates with various electrophiles is also examined. In the case of protected cyanohydrines the alkylation with methyl iodide leads to the trans adducts whatever the ring size may be. On the contrary, when using an aminonitrile this reaction is limited to the five membered ring series. However, with a more reactive electrophile such as the ethyl bromoacetate we obtain the 2,3-disubstituted trans cyclohexanones. The reaction of aminonitriles acetyl equivalents on a-substituted a-cyclenones gives results comparable with those of the benzoyl equivalents while masked formyl anions lead to cis-trans mixtures. From all 1,4 adducts the corresponding 2-substituted 3-acyl cyclanones were prepared preserving their cis or trans stereochemistry except for the cyclopentanone series. The 1H NMR 2D configurational and conformational study of the 3-substituted 2-phenylseleno cyclohexanones showed a preference of the SePh group for the axial position. To explain these results we propose a stabilization resulting from an overlap of the σ* orbitals of the C-SePh bond with the π orbitals of the neighboring carbonyl
32
Perny, Sébastien. "Alignement de cristaux liquides par irradiation en lumière linéairement polarisée de film minces de polymères photoréticulables." Cachan, Ecole normale supérieure, 1998. http://www.theses.fr/1998DENS0042.
Abstract:
L'objectif de ce travail de thèse a été en premier lieu de concevoir et de synthétiser quatre polymères photosensibles utilisables industriellement comme films d'alignement des cristaux liquides. Dans un deuxième temps, des études par spectroscopie UV et IR ont permis de caractériser l'anisotropie et l'évolution de la composition de ces matériaux en cours d'irradiation en lumière linéairement polarisée. Dans le cas général, il a ainsi été possible de mettre en évidence la compétition de deux photo réactions : la cycloaddition 2+2 et l'isomérisation trans/cis. Ainsi, trois espèces cohabitent au sein du film de polymère irradié : les dimères, produits de la cycloaddition de chromophores agrégés ; les isomères cis, issus de l'isomérisation des chromophores isoles ; les chromophores initiaux qui n'ont pas réagi. De plus, nous avons pu constater que l'orientation préférentielle des chromophores inchangés était perpendiculaire a l'axe de polarisation et que, dans certains cas, les dimères étaient préférentiellement formes parallèlement a l'axe de polarisation. Enfin les propriétés d'alignement de ces matériaux ont été étudiés en confinant des cristaux liquides entre deux films de photopolymères irradies. Leur comportement a ensuite été compare a ceux du pvci et du poly(7-methacryloyloxycoumarine) afin de clarifier le mécanisme de photo alignement. Deux mécanismes ont du être envisages. Dans un cas, la sélectivité axiale des réactions photochimiques en lumière polarisée consomme les chromophores préférentiellement orientes le long de l'axe de polarisation. L'anisotropie du film est donc uniquement due à la présence de chromophores inchangés, initialement perpendiculaires à l'axe de polarisation, et le film induit un alignement homogène planaire suivant cet axe. Dans le deuxième cas, l'anisotropie du film est essentiellement due à la formation de dimères le long de l'axe de polarisation, et le film induit un alignement homogène planaire suivant l'axe de polarisation.
33
Lin, Jhih-Yu, and 林芷羽. "Effect of Precursors on the formation of crystalline phase of CIS and CIGS powders." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/60966841405130469960.
Abstract:
碩士中原大學
化學研究所
97
Solar cells with chalocopyrite structure have two major types: copper indium selenium series, CuInSe2[CIS], and copper indium gallium selenium series, Cu(In1-xGax)(Se1-ySy)[CIGS]. Due to the advantages of high photoelectric efficiency and low materials cost, it is worth to keep studying these two material systems. In this experiment, three kinds of different precursors were used to synthesize CIS and CIGS powder. XRD, SEM, EDS, and TEM were then used to analyze crystallization, composition, particle size, and morphology of powder products. The composition of the product can be adjusted when salts of CuCl2, InCl3, and SeCl4 were used to synthesize the CIS powder. The product can be single phase if precursors of [Cu4{Se2P(O’Pr) 2}4] and [In{Se2P(O’Pr) 2}3] were used. It is hard to synthesize CIGS powder by using Cu, In, Ga, and Se powder directly, because all these powder can not be completely dissolved into the solvent used in this experiment. The composition of the product can be adjusted when salts of CuCl2, InCl3, GaCl3 and SeCl4 were used to synthesize the CIGS powder. The product can be almost single phase if precursors of [Cu4{Se2P(O’Pr) 2}4], [In{Se2P(O’Pr) 2}3], and GaCl3 were used.
34
Fu, Jinlong. "Thermal cis-to-trans isomerization mechanism of N-(phenylazo)-substituted nitrogen heterocycles." Thesis, 2008. http://hdl.handle.net/10012/4134.
Abstract:
Triazenes, compounds containing a diazoamino moiety (–N(1)=N(2)–N(3)<), are known for their reversible cis-trans isomerization character and hence, have the potential to be used in photoswitchable devices and photostorage media. However, little is known about their cis-trans isomerization mechanism. In this thesis, kinetic studies on the thermal cis-to-trans isomerization of N-(phenylazo)-substituted nitrogen heterocycles are presented. It is shown that the isomerization rate constant increases as the size and electron-donating character of the cyclic amine increases, as the electron-withdrawing character of the para substituent group on the phenyl ring increases, and as the polarity of the solvent increases. All these trends are interpreted in terms of a rotational isomerization mechanism involving a dipolar transition state. In addition, photolytic cleavage of the N(2)–N(3) bond of target substrates is shown to be affected as well by the size and electronic character of the cyclic amine, the electronic character of the phenyl ring substituent, and the polarity of the solvent, with the result that the photolysis yield increases as the isomerization rate decreases.
Theoretical calculations on target substrates both in the gas phase and various solvents were also performed based on DFT-B3LYP/6-31+G* method. Overall, the cis-to-trans isomerization is predicted to take place through rotation around the N(1)=N(2) bond. Furthermore, the calculated energy barriers are found to be influenced by the size and electronic character of the cyclic amine, the electronic character of the phenyl ring substituent, and the polarity of the solvent, consistent with the effects obtained experimentally from the kinetic studies.
35
Liu, Zhi-Hong, and 劉志鴻. "The Effect of Substrate Concentrations on Cis,Cis-Muconate Production from Benzoate by Pseudomonas sp." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/43052231740546749953.
Abstract:
碩士義守大學
生物技術與化學工程研究所
101
Muconic acid (MA) can be transformed to adipic acid by using the Pt as catalytic agent at 50 psi and room temperature. Adipic acid is an important raw material for producing plastics such as nylon 6,6 which is produced through chemical synthesis; however, that chemical manufacturing will cause a lot of greenhouse gases of NOx to be discharged during the process thus adding to the greenhouse effect. Energy consumption and environmental pollution can be reduced if white biotechnology is used to replace the chemical synthesis to produce the MA. Our laboratory obtained a bacterial strain from the sludge of industrial wastewater treament. The strain, identified to be Pseudomonas sp., has been mutated to a high-yield MA strain by chemical mutagens and proper screening strategy. We found the compositions of the complete medium by using the response surface methodology, further discussed the impacts of the mass transfer of oxygen in fermentation batch on the generation of MA, and the comparison of the compound nutrition assembly used in fed-batch cultivation. The goal of this study is to discuss how to improve the efficiency of product accumulation and cell growth after amplifying the MA procedure by adjusting the concentrations of substrate and improving the procedures. We studied the inhibition level of the product concentration on the MA produced by cells, the test found that the speed of cell growth was reduced by 40% and the productivity was decreased by 50% when the MA concentration was higher than 10g/L; and the cellular productivity could be improved to 1.2 g MA /g DCW/hr by keeping the dissolved oxygen value above 30% during transference of the benzoic acid to generate MA. In the aspect of procedural improvement, variable feeding is chosen to replace periodic feeding. It can not only improve the specific growth rate by 380%, but also increase the original productivity by 140%. In the aspect of substrate concentrations, the proper glucose concentration and C/N ratio are used to achieve the aims of cell growth and productivity improvement: When the glucose concentration is 10 g/L with 0.5 of C/N ratio, the specific growth rate can reach 0.63 hr-1 and the cellular productivity is 0.86 g MA /g DCW/hr. Finally, this process verifies that the addition of benzoic acid in the batch stage can induce the activity of the genes used to regulate and control the metabolism pathway of MA production in Pseudomonas sp., which is conducive to the accumulation of MA in the fed-batch fermentation.
36
Liu, Yu-Wei, and 劉郁緯. "The Effect of Selenization Parameter on CIGS Solar Cell Absorber Layer." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/26781765088337059444.
Abstract:
碩士龍華科技大學
工程技術研究所
101
In this work, copper indium gallium diselenide (CIGS) solar cells were deposited on soda-lime glass substrates by two-step method. Firstly, the Cu/Ga/In alloy precursors of approximately 750 nm thickness were deposited sequentially on glass substrates using Cu–Ga alloy and In targets by direct current magnetic sputtering system. Secondly, the metallic precursors were then selenized (about 2 μm thick) with solid Se pellets in a closed vacuum furnace. To study the effect of annealing on the chalcopyrite CIGS structure properties, the films have been annealed in vacuum. The influence of various annealing process parameters (annealing temperature, chamber pressure, heating rate and holding time) on the structural, morphological and properties of CIGS films were investigated.
37
Hei-Sheng, Tsai, and 蔡輝昇. "A STUDY OF EFFECT FOR CHT CONDUCTION OF CIS." Thesis, 1998. http://ndltd.ncl.edu.tw/handle/32049858240957576390.
Abstract:
碩士國立臺灣科技大學
工程技術研究所
86
Corporate Identity System (CIS) is a total communication system which contains mind identity, behavior identity and visual identity; meanwhile, CIS has become a powerful strategy for managing current enterprise successfully. In order to alter former conservative corporation image and to establish a new、cordial、sincere and effective image for enterprise, CHT conducts CIS formally when reorganized. This study applies objective and scientific method of investigation to predict effect of CHT conduction of CIS1. By the Interview Survey, we found out that due to there is no exclusive administrative department for building up enterprise image for CHT, CHT had difficulty of executing identification of organization；meanwhile, because of lack of sampling when making enterprise image, CHT had problems of deficiency, mistake and misuse of regulations. 2. Compared with other private telecommunications companies, CHT had a negative comment of conservation, however, CHT also got positive appraise with powerful enterprise character and made internationally magnificent performance.3. The Questionnaire Survey shows that the investigated people are sure of that the effect of CHT conducting of corporation identification. 4. After reviewing the research, it is no doubt that the factors affecting the effect of use of CIS are emotional、rational、traditional and modern concepts, these parts play important roles and influence others mutually. The main cause influencing recognizing of particular styling (Mascots) is because of the design of corporation mark、 the characteristics of professions and the attributes of enterprises. Therefore, CI offers opportunities for enterprise to deliberate、evaluate and design strategies for im5. This study utilizes the modified method of SD for finding out the efficiency of conducting CI. Is the modified method more effective or not depends on further detailed and long researches for verification.
38
St-Jean, Olivier. "Addition stéréosélective de nucléophiles sur un centre acétal : synthèse de nucléosides 1’,2’-cis." Thèse, 2010. http://hdl.handle.net/1866/4738.
Abstract:
Plusieurs analogues de nucléosides thérapeutiques (Ara-C, Clofarabine), utilisés
pour le traitement de leucémies, présentent un arrangement 1’,2’-cis entre la nucléobase
reliée au centre anomère et le substituant (électroattracteur) en C-2’. Récemment, notre
laboratoire a développé une approche synthétique pour former sélectivement des
analogues de nucléosides et de thionucléosides 1’,2’-trans et 1’,2’-cis à partir de
précurseurs acycliques.
Ce mémoire présente une nouvelle méthodologie pour accéder efficacement aux
analogues de nucléosides 1’,2’-cis à partir de furanosides. Différents groupements en
position anomérique ont été examinés, sous conditions cinétiques en utilisant le bromure
de diméthylbore pour générer sélectivement des produits acycliques ou cycliques. Les
intermédiaires cinétiques de différents furanosides de méthyle formés en présence de
Me2BBr ont été piégés in situ par un thiol pour générer des thioacétals acycliques avec
de bonnes voire d’excellentes diastéréosélectivités. Les produits générés sont en accord
avec une rétention globale de l’information stéréochimique du centre acétal et deux
déplacements SN2 consécutifs ont été suggérés pour rationaliser ces résultats. Toutefois,
l’objectif de synthétiser des analogues de nucléosides à partir de furanosides de méthyle
a échoué.
Tel que démontré par le Dr Michel Prévost, l’activation par Me2BBr des lactols
des quatres différents furanosides suivie d’une addition in situ d’une base silylée a
permis de former diastéréosélectivement les analogues de nucléosides 1’,2’-cis
correspondants avec d’excellents rendements. Nous avons démontré que d’autres
substrats peuvent être employés et que l’induction stéréochimique est sous contrôle du
substituant électroattracteur en C-2. D’autres acides de Lewis, tel que TMSBr, peuvent
également être utilisés.
Cette méthodologie a également été étendue à d’autres nucléophiles tels que des
Grignards ou des éthers d’énols silylés, conduisant à de bonnes sélectivités.Many therapeutically relevant nucleoside analogs (Ara-C, Clofarabine) for the treatment of leukemia have a 1’,2’-cis arrangement between the nucleobase attached at the anomeric center and the non-hydrogen substituent at C-2’. Recently, our laboratory has developed a versatile approach to the synthesis of 1’,2’-trans and 1’,2’-cis nucleoside and thionucleoside analogues from acyclic scaffolds. This work will present a new methodology to access efficiently 1’,2’-cis nucleoside analogues from cyclic furanoside. Activation of various anomeric groups by Me2BBr was investigated, and under kinetic control acyclic substrates or cyclic ones could be generated selectively. Trapping the kinetic product of methyl furanoside formed in presence of Me2BBr by thiol in the presence of base led to the formation of acyclic thioacetal in good to excellent diastereoselectivity. The results obtained are in accordance with total retention of the stereochemical information of the acetal moiety and thus suggested that the mechanism of these two reactions is two successive SN2 displacements. The objective of synthesizing nucleoside analogs from methyl furanoside was unsuccessful. As shown recently by Dr Michel Prévost, activation of all four furanoside lactol scaffolds by Me2BBr with an in situ addition of silylated nucleobase afforded 1’,2’-cis pyrimidine nucleoside analogues in very good yields and with diastereoselectivities greater or equal to 20:1. Expending this methodology to other scaffolds provided evidence of stereoelectronic control of the C-2 electron-withdrawing substituent. Other Lewis acids such as TMSBr can be used. This methodology was also applied to other nucleophiles such as allyl Grignard and silylated enols ethers, which were successfully alkylated in good yield and 1,2-cis diastereoselectivity.
39
Lai, Yi Cheng, and 賴裔澄. "The effect of thermal treatment for metal alloys on CIGS solar cells." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/52363593730791924788.
Abstract:
碩士長庚大學
化工與材料工程學系
98
Due to the features of saving material, simple process, large-scale fabrication, etc., the thin film solar cell is a potential candidate of low cost solar energy product. Among the thin film solar cell products, amorphous silicon attracts more intention and has been developed. However, there is a barrier for the improvement of efficiency by using this material. In recent years, another thin film material, Copper Indium Gallium Selenide (CIGS), becomes the a interesting material due to its advantages, such as : (a) low fabrication cost, (b) low energy requirement for manufacture, (c) large area device with higher efficiency, (d) high production yield and (e) flexible usage of substrate (ex. glass, stainless, polymer, tin foil, etc.) It is believed that the CIGS will be the main stream of thin film solar cell. In this study, we try to deposit various metal materials on Al-doped zinc oxide (AZO) conduction film. The metal materials include Ni/Ag and Ni/Au in this study. After deposition of metal alloy, the samples were annealed with different annealed temperature in the range of 200~400℃. We use the transmission line model (TLM) method to analyze the ohmic contact resistivity of samples. In addition, this study also deposited the optimized metal materials/AZO on Copper Indium Selenide (CIS) thin film solar cell. Then the samples were processed with different annealing conditions. The efficiency stability of solar cell is also analyzed.
40
Lin, Tzu-Ying, and 林姿瑩. "Mo Back Contact Effect on One-step Sputtering Chalcopyrite CIGS Thin Films." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/93745170180572455979.
41
Wu, Yin-Ting, and 吳胤霆. "Gallium diffusion effect on CIGS Synthesis by Solvothermal Refluxing method and selenization." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/z992ev.
Abstract:
碩士國立臺南大學
電機工程學系碩博士班
106
In this paper, we are mainly studying the synthesis of semiconductor material thin film CuIn0.7Ga0.3Se2. The quaternary phase CuIn0.7Ga0.3Se2 nano-ink was prepared by Solvothermal Refluxing Method with a simple, convenient and low-cost non-vacuum technology. Use elemental powder of copper (Cu), indium (In) , gallium (Ga) and selenium (Se) powder as material with stoichiometric ratio of 1 : 0.7 : 0.3 : 2 to add into the novel organic solvent D400 (polyetheramine) And then heats at 200-250℃ for 3-20 hours to discuss. First of all, we observe the phase change at different time, and then we know the reaction mechanism of Cu, In, Ga, Se and D400 (polyetheramine) by measurement further to deduce the reaction pathway of CuIn0.7Ga0.3Se2 and the effect of Ga at this experiment. We find Ga is the key to synthsis CuIn0.7Ga0.3Se2 and successfully synthesize pure phase CuIn0.7Ga0.3Se2. We think Ga is more difficult than In to join the reaction of synthesizing CuIn0.7Ga0.3Se2 because the activity difference and both of them are III at Periodic Table of Elements. It means they have similar chemical properties lead to competition. So we try to form CuGaSe2 to make Ga join the reaction first. But it is hard to synthsis a pure CuGaSe2 with Solvothermal process and low reaction temperature. We do our best to synthsis a pure CuGaSe2 and discuss his reaction¬ way. And then we mixture the pure CuGaSe2 and CuInSe2 with a 3: 7 ratio to selenized at 600~675OC to synthsis CuIn0.7Ga0.3Se2, improve its crystallinity and observe the characteristics.
42
Gao, Shu-Yu, and 高樞宇. "Effect of Mo Deposition Conditions on Various Substrates for CIGS Solar Cells Applications." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/30344296389834862740.
Abstract:
碩士中華技術學院
電子工程研究所碩士班
97
Molybdenum metal (Mo, Molybdenum) with a high degree of optical reflectivity , low resistance and high compressive stress, and good ohmic contact withCuInSe2 is an indispensable back electrode material for CIGS solar cells. In this study, DC SPUTTER is used to deposite Mo metal thin films on various substrates such as stainless steel, Al2O3, SiO2, etc,.After deposition, SEM, AFM, and XRD are used to analyze the deposition results. From the measurements, the Mo deposition on SiO2/ stainless steel substrates shows the best film quality. In this study, the optimum parameters for depositing Mo metal thin films on SiO2 substrate is as following : substrate temperature 200 ° C, sputtering power 100W.
43
Chang, Chun-Teng, and 張駿騰. "Investigation of the effect of hot-filament enhanced selenization on CIGS thin films." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/99057498045512810594.
Abstract:
碩士明道大學
材料科學與工程學系碩士班
99
The aim of this experiment is to investigation of selenization treatment on CIGS thin films by hot-filament enhanced. Preparation of high quality CIGS thin-film to upgrade reaction efficient of CIG precursor layer and Se vapor by hot filament enhanced selenization system. Preparation of CIGS thin films, the first deposition CIG precursor on glass substrate by RF magnetron sputtering system, after to use hot filament enhanced selenization system, investigation selenization parameter of hot filament temperature, annealing time, annealing temperature and Se vapor temperature respectively. By means of X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), energy dispersive spectrometer (EDS) and hall effect, it was found that structure, surface morphology, chemical composition and electrical characteristic of CIGS thin films. Finally, the results show the better characteristic of CIGS thin films in the hot filament temperature at 350 °C, annealing time at 30 minutes, annealing temperature at 550 °C and Se vapor temperature at 210 °C. Therefore it verified that hot filament enhanced selenization was a well way.
44
Lin, Dong Liang, and 林東良. "The Effect of Radio Frequency Plasma Enhanced Selenization Treatment on CIGS Thin Films." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/14460414654328389423.
Abstract:
碩士明道大學
材料科學與工程學系碩士班
100
The aim of this experiment is to investigate the selenization treatment in CIGS thin films by Radio Frequency Plasma Enhanced Selenization Treatment whith the parameters including the pressure, power, annealing time and annealing temperature. In this study, the films are characterized by using scanning electron microscopy, X-ray diffraction, energy dispersive spectrometer, X-ray photoelectron spectroscopy and hall effect. In traditional way, the H2Se is generally used in selenization treatment, but it has a highly cost issue. To solve the problem, we using the self-developed system. The Se powder were heated by heater and the caused vapor were guide into the chamber to react the selenization process. To prepare the high quality CIGS thin-film to upgrade reaction efficient of CIG precursor layer. Finally, the CIG precursor film with lower oxygen content can obtain larger grains, smooth surface morphology and completely selenized CIGS film at plasma power of 40 W, annealing temperature of 550°C, Se powder temperature of 250°C, and annealing time of 30 min.
45
Hsiang-Yuan, Tan, and 譚翔元. "The Research of Optical Properties of Surface Plasma Effect on the CIGS Solar cell." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/88876359898552504828.
Abstract:
碩士國立中正大學
光機電整合工程研究所
101
In our study, we sputtering a metal nano structures on the surface of absorption layer (CIGS layer) and TCO layer (AZO layer) of CIGS Solar Cell, and then annealing so that the metal nano structures on the substrate will become a nano particle or nano island. We using scanning electron microscope and atomic force microscope to observe the metal nano particle’s shape and size to compare the transmittance and absorbance spectrums, then we can find out the optical properties of nano particles. We find out that the sample which annealing with Ag 5nm thickness and temperature 350℃ has the highest peak and the best average transmittance rates, which the peak is at 340nm has 146.97％ and the average transmittance rate about 74.7%, though the sample’s transmittance do not higher than the reference, but at the wave band (about 300-400nm ), the transmittance has a peak higher than the reference, we speculate that is because of the LSP resonance effect enhancement. About samples of CIGS, because the metal Ag and Au will interact with CIGS when annealing, so we can’t distinguished the shapes and size with SEM and AFM.
46
Huang, XinKui, and 黃信魁. "Detecting Cis-Trans Isomerization of Para Methyl Red by using Silicon Field-Effect-Transistors." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/662zbn.
Abstract:
碩士國立臺北科技大學
有機高分子研究所
105
We showed detection of the transition between cis and trans states of a para-methyl red using silicon field-effect-transistors. Para-methyl red is a photoisomerizable molecule: the transition from low-energy trans to high-energy cis states can be stimulated by irradiation of 365 nm UV light, and the reversed process can be accelerated by irradiation of 450 nm visible light. The structural change can produce a change in the electron cloud distribution, and hence a change in the molecular dipole moment, which can be detected by the field-effect-transistors. In this study, the photon-trigged structural transitions were conducted in vacuum, in the air and in various liquid conditions. It was found that in pure water the photon trigged molecule structural changes were most prominent and reproducible. It took about 3 minutes of UV irradiation to excite the molecules to the cis equilibrium state, and the spontaneous relaxation time from the cis equilibrium state to trans equilibrium state was found to be about 112 sec. It was also found that by irradiation of visible light for 60 sec, this relaxation process could be accelerated and shortened to 3 sec. Since field-effect-transistors detect the molecular dipoles, and thus would not apply force of any kinds to the molecules under study. This is in contrast to the popularly used optical detection technologies in which the probe light may, to a certain extent, disturb the molecule structure. In view of that, our field-effect-transistor based detection method provides a unique approach to reveal the nature of the structural state transitions.
47
Lin, Hsiao-Hui, and 林小慧. "Study on Effect of the CISC Instructional Strategy on the Physical Science Learning for Junior High Students." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/03996551817933053091.
Abstract:
碩士國立台北師範學院
自然科學教育研究所
94
The research aimed to scaffold students constructing the mental images and reach the scientific thinking of the structure of matter by integrating the Concrete Image Spatial Concepts (CISC) instructional strategy into physical science teaching. Both “models” and “stereoscopic dynamic pictures” were employed as the principle axis of CISC, with which a set of models simulating “the microscopic structure of atom” , “atom and molecule”, and the “formation of compound” was set up. 125 junior high eighth-grade students from a Taipei County school participated in this research. They were randomly assigned in two groups (experimental group receives 3-week CISC treatment, control group receives 3-week non-CISC teaching). The validated instrument tilted as “Junior High Students’ Achievement of Physical Science”、“Spatial Ability” and “Reasoning Ability” was to apply as pre-test and post-test in order to examine the effectiveness of CISC strategy by analysis of covariance. Results showed that there was not significant difference between the achievement of Physical Science of two groups, but the score was higher experimental group than control group. And there was significant difference between the achievement of Spatial Ability and Reasoning Ability of two groups. From the quantitative data collecting from statistical analysis, they indicated that CISC not only elevating the learners' mental images operational abilities but also catalyzing the interactions between 2D/3D representations. It appeared that CISC strategy could lessen students’ cognitive loading, reduce the students’ perplex by abstract concepts, and support students constructing relevant “mental images” and developing spatial ability and reasoning ability to understand science concepts.
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(8848484), Arturo Garcia. "EXPERIMENT AND MODELING OF COPPER INDIUM GALLIUM DISELENIDE (CIGS) SOLAR CELL: EFFECT OF AXIAL LOADING AND ROLLING." Thesis, 2020.
Abstract:
In this paper various applications of axial tensile load, bending load, and rolling loading has
been applied to a Copper Indium Gallium Diselenide (CIGS) Solar Cell to lean how it would affect
the solar cell parameters of: Open circuit voltage (Voc), Short circuit current, (Isc), Maximum power
(Pmax), and Efficiency (EFF), and Fill Factor (FF). These Relationships were found for with three
different experiments.
The first experiment the applies axial tensile stress is to a CIGS solar cell ranging from 0 to
200 psi with various strain rates: 0.0001, 0.001, 0.01, and 0.1 in/sec as well as various relaxation
time: 1min, 5min, and 10 min while the performance of solar cell is measured. The results of this
gave several trends couple pertaining the Voc . The first is that open circuit voltage increases
slightly with increasing stress. The second is the rate of increase (the slope) increases with longer
relaxation times. The second set of trend pertains to the Isc. The first is that short circuit current
generally is larger with larger stress. The second is there seems to be a general increase in the Isc
up to a given threshold of stress. After that threshold the Isc seems to decrease. The threshold stress
varies depending on strain rate and relaxation time.
The second set of experiments consisted of holding a CIGS solar cell in a fixed curved
position while it was in operational use. The radii of the curved cells were: 0.41, 0.20, 0.16, 0.13,
0.11, 0.094, and 0.082 m. The radii were performed for both concave and convex cell curvature.
The trends for this show a slight decrease in all cell parameters with decreasing radii, the exception
being Voc which is not effecting, the convex curvature causing a slightly faster decrease than the
concave. This set of experiments were also processed to find the trends of the single diode model
parameters of series resistance (Rs), shunt resistance (Rsh), dark current (I0), and saturation current
(IL), which agreed with the experimental results.
The second experiment consisted of rolling a CIGS solar cell in tensile (cells towards dowel.)
and compression (cells away from dowel) around a dowel to create internal damage. The diameter
of the dowels decreased. The dowel diameters were: 2. 1.75, 1.25, 1, 0.75, 0.5, and 0.25 inches.
This experiment showed similar trends as the bending one but also had a critical diameter of 1.75
in where beyond that damage much greater.
Finally a parametric study was done in COMSOL Multiphysics® to examine how changes
in the CIGS material properties of electron mobility (EM), electron life time, (EL), hole mobility
15
(HM), and Hole life time (HL) effect the cell parameters. The trends are of an exponential manner
that converges to a given value as the material properties increase. When EL, EM, HL are very
small, on the order of 10-4 times smaller than their accepted values, a transient like responses occurs.
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Jian, Song-rui, and 簡松瑞. "The effect of ZnO buffer layer on CIGS solar cell by Successive Ionic Layer Adsorption And Reaction method." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/52557401608955358348.
Abstract:
碩士國立臺南大學
電機工程學系碩士班
100
In the study, zinc oxide was grown by Successive Ionic Layer Adsorption And Reaction (SILAR) method and it was applied to a buffer layer for Cu(InGa)Se2 solar cell. This way was a very simple wet process and low cost and considered to be suitable for large area processing. First, the ZnO film were deposited on glass substrates by Successive Ionic Layer Adsorption And Reaction. The ZnO film was be investigated by the various of the temperature. For this purpose scanning electron microscopy, SEM, as well as various operating modes of atomic force microscopy, AFM, were utilized. In addition, the crystallinity and the composition of the films were studied by X-ray diffraction and X-ray photoelectron spectroscopy (XPS).Optical properties of ZnO thin films were characterized by ultraviolet-visible-near infrared (UV-VIS-IR) spectrophotometer and photoluminescence (PL). It found that the surface roughness of ZnO film was be improved and a transmittance of above 95% in the visible range were obtained by the increase of temperature. The best ZnO film was be obtained as the temperature was 180oC. CIGS solar cell have been fabricated using ZnO buffer layer. The best efficiency was obtained as the ZnO film was grown at 180oC. Further, the ZnO buffer layer thickness was investigated. The best CIGS efficiency was obtained as the thickness of the ZnO buffer layer was 200 nm. An active area efficiency of 4.13% with VOC = 0.42 V, JSC = 22.68 mA/cm2, FF = 43.37%.
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WU, CHIA-CHUN, and 吳佳峻. "Effect of Different Composition Ratio of Quaternary Alloy Targets Prepared by DC Magnetron Sputtering for CIGS Solar Cells." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/67469249721702657539.
Abstract:
碩士逢甲大學
光電學系
105
CIGS solar cell is one of the most promising candidates for future photovoltaic application, because it is a material with direct band gap, high absorption coefficient, tunable band gap and high material stability. In this study, CIGS thin films were deposited by magnetron sputtering from two quaternary targets with the composition of Cu-poor and Cu-rich target. As-deposited thin films were selenized by rapid thermal annealing process to improve the quality of absorber layers. We investigated the influence of post-annealing temperature and post-annealing time on material composition, crystalline structure, raman spectrum and microstructure. We observed when CIGS film annealed at 500C and for 30 minutes, it has better crystallization and less second phase. The study also used chemical bath deposition (CBD) and magnetron sputtering to produce buffer layers and analyzed optical properties and microstructure. Solar cell structure, from top to bottom, were stacked by Ag (Sputtering, 300 nm), AZO (Sputtering, 400 nm), i-ZnO (Sputtering, 50 nm), CdS (Sputtering or CBD, 50 nm), CIGS (Sputtering, 1500 nm~2000 nm), Mo (Sputtering, 1000 nm) and SLG. The measured highest conversion efficiency of the CIGS solar cell is 4.6 % with an open voltage of 412.5 mV, short circuit current density of 19.14 mA⁄cm^2 and fill factor of 57.75 % by Cu-poor target. Solar cell fabricated by Cu-rich target showed a conversion efficiency of 0.7 % with an open voltage of 315 mV, short circuit current density of 6.09 mA⁄cm^2 and fill factor of 34.86 %. Solar cell efficiency can be improved by adjusting ratio of quaternary-alloy target.