Relevant bibliographies by topics / OR GHX / Dissertations / Theses
To see the other types of publications on this topic, follow the link: OR GHX.

Dissertations / Theses on the topic 'OR GHX'

Author: Grafiati
Published: 4 June 2021
Last updated: 1 February 2022

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the top 50 dissertations / theses for your research on the topic 'OR GHX.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.

1

Aldubyan, Mohammad Hasan. "Thermo-Economic Study of Hybrid Photovoltaic-Thermal (PVT) Solar Collectors Combined with Borehole Thermal Energy Storage Systems." University of Dayton / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1493243575479443.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Lubbers, Ellen MR. "Investigation of adiponectin and its receptors in mouse-models of altered growth hormone action: Attempts to understand the link between adipose tissue and longevity." Ohio University Honors Tutorial College / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=ouhonors1340185494.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Junnila, Riia Karoliina. "In vitro characterization of human growth hormone mutants." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2011. http://dx.doi.org/10.18452/16311.

Full text
Abstract:
Wachstumshormon (GH) besteht aus 191 Aminosäuren, hat eine Molekülmasse von 22kD und ist essentiell für postnatales Wachstum. Es wird aus der Adenohypophyse freigesetzt. GH bindet an einen GH-Rezeptor (GHR) und aktiviert somit über intrazelluläre Signalvorgänge Zielgene, insbesondere das, welches für die Kodierung von insulin-like growth factor (IGF-1) zuständig ist. IGF-1 vermittelt den Großteil aller GH-Signale. Zusammen mit den bereits bekannten GH Mutanten R77C und D112G ist in dieser Studie der neue GH Mutant d188-190 charakterisiert worden. Alle drei Mutanten wurden in heterozygoter Form in kleinwüchsigen Patienten identifiziert. Diesen Patientendaten zu Folge schien es möglich, dass d188-190 eine GH-antagonistische Wirkung besitzt. Zusätzlich wurde die extrem konservierte C-terminale Disulfidbrücke des GH im Mutanten d188-190 unterbrochen vorgefunden. Die Auswirkung der Unterbrechung wurde durch Substitution einer oder beider involvierter Cysteine durch Alanine untersucht. Alle Mutanten und Wildtypen des GH wurden in menschlichen embryonalen Nierenzellen (HEK-293) angezüchtet und eine Reihe von in vitro Experimenten sind für deren Charakterisierung etabliert worden. Es zeigte sich, dass d188-190 keine GH-antagonistische Wirkung besitzt. Im Vergleich zum Wildtyp weist der Mutant eine verminderte Bindungsaffinität zu GH, schwächere biologische Aktivität und höhere Stabilität auf. R77C und D112G sind dem Wildtyp GH sehr ähnlich. Die Disulfidbrücke ist wichtig für die Rezeptorbindung und für die biologische Aktivität von GH. Wenn ein Cystein entfernt wird vermindert sich die Stabilität des Moleküls. Dieser Effekt kann durch Entfernen des zweiten Cysteins wieder rückgängig gemacht werden. Die in dieser Studie etablierten Experimente können Verwendung finden in der Charakterisierung bislang nicht bekannter GH Mutanten und können darüber hinaus zur Behandlung von Patienten eingesetzt werden.
Growth hormone (GH) is a 22 kD, 191-aa, pituitary-derived peptide hormone that is essential for postnatal growth. GH signals via binding to GH receptor (GHR), which initiates intracellular signal transduction pathways. This leads to activation of target genes, most importantly the one encoding insulin-like growth factor (IGF)-1, which mediates most GH action. In this study a novel GH mutant, d188-190, was characterized along with previously reported GH mutants R77C and D112G. All of these mutants had been identified in heterozygous form in patients with retarded growth. Based on patient data, d188-190 was thought to be a GHR antagonist. Moreover, the extremely conserved C-terminal disulfide bridge of GH was disrupted in mutant d188-190 and its role was studied by substituting one or both of the involved cysteines with alanines. All mutants and wild type (wt) GH were produced in human embryonic kidney (HEK)-293 cells and an array of in vitro experiments was established for their characterization. It turned out that the novel d188-190 mutant is not a GHR antagonist after all. It has a diminished binding affinity to GHR, low biological activity and high stability compared to wt GH. R77C and D112G are rather similar to wt GH. The disulfide bridge is important for receptor binding and biological activity of GH. If one of the cysteines is removed the stability of the molecule drops but this can be reversed by removing both cysteines. If further GH mutants are to be identified, the established array of experiments will be useful for their fast characterization and could even contribute to correct treatment of patients.
APA, Harvard, Vancouver, ISO, and other styles
4

Tolle, Virginie. "La ghreline, une nouvelle hormone gastrointestinale se liant au récepteur des GH sécrétagogues : du contrôle de la sécrétion de l'hormone de croissance (GH) à la régulation de la prise alimentaire et des rythmes veille/sommeil." Paris 6, 2002. http://www.theses.fr/2002PA066353.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Liberato, Marcelo Vizoná. "Caracterização estrutural de endoglucanases da família GH5 e beta-glicosidases da família GH1: interação enzima-substrato." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/76/76132/tde-28012014-142924/.

Full text
Abstract:
A celulose é o biopolímero de maior abundância no mundo e tem potencial para se tornar fonte de energia renovável através de sua transformação em açúcares fermentáveis, que por sua vez serão transformados em etanol. A recalcitrância da celulose, principal dificuldade encontrada no processo, pode ser superada com o auxílio de enzimas (celulases). Ao menos três enzimas celulolíticas são necessárias para a degradação total da celulose, incluindo as celobioidrolases, que hidrolisam as ligações glicosídicas das extremidades redutoras e não redutoras da cadeia, as endoglucanases, que clivam a cadeia de celulose amorfa randomicamente, e as beta-glicosidases, que produzem glicose através dos celo-oligômeros. Mas para que esse processo se torne financeiramente viável é necessário conhecer o funcionamento, otimizar a atividade e aumentar a produção dessas celulases. Com o intuito de avançar na compreensão da função e estrutura dessas enzimas, o presente trabalho teve como objetivo o estudo estrutural de beta-glicosidases da família GH1 e endoglucanases da família GH5. Na primeira parte do trabalho, a expressão da endoglucanase II de Trichoderma reesei não foi alcançada, mesmo utilizando diferentes organismos e condições de expressão. Porém, na segunda etapa, foi obtida a expressão, purificação e os primeiros ensaios de cristalização de 11 beta-glicosidases bacterianas da família GH1 e 8 endoglucanases bacterianas da família GH5. Dentre elas, três beta-glicosidases e uma endoglucanase de Bacillus licheniformis foram cristalizadas e tiveram sua estrutura resolvida. As beta-glicosidases, apesar de possuírem o enovelamente similar, apresentaram variações no tamanho e posição das alças formadoras da fenda catalítica e divergem em relação a um dos aminoácidos importantes para a estabilização do substrato. Essas diferenças podem ajudar a explicar o mecanismo dessas enzimas para reconhecer substratos distintos. A endoglucanase da família GH5, possuindo dois módulos acessórios, foi cristalizada tanto na forma apo quanto complexada ao substrato celotetraose. O segundo módulo acessório possivelmente é um domínio de ligação à celulose (CBM) e seus resíduos aromáticos, que são responsáveis pela interação com o substrato, parecem complementar o sítio catalítico, sendo assim um novo mecanismo de auxílio enzimático de um CBM. O primeiro módulo acessório não possui um aparente sítio de interação com carboidratos e provavelmente funciona como um conector entre domínio catalítico e o CBM. O posicionamento do substrato no sítio de ligação é parecido com outras estruturas já determinadas, porém, suscita algumas dúvidas sobre a função dos resíduos catalíticos que é conservada na família. O carbono anomérico do substrato possui uma densidade eletrônica contínua com o glutamato da fita β4 (que deveria ser o ácido/base) e está mais próximo dele que do glutamato da fita β7 (que deveria ser o nucleófilo).
Cellulose is the most abundant biopolymer in the world and can become a renewable energy source through its transformation in fermentable sugars, which will be converted in bioethanol. The cellulose recalcitrance, main difficulty in the process, can be overcome with the aid of enzymes (cellulases). At least three cellulolytic enzymes are required for complete hydrolysis of cellulose, including cellobiohydrolases for hydrolyzing the glycosidic linkages from the reducing and non-reducing chain ends, endoglucanases for randomly cleaving cellulose chains in the amorphous regions, and beta-glucosidases for producing glucose from the solubilized cello-oligomers. But, to become a financially viable process it is necessary to know the mechanism, optimize the activity and improve the production of these cellulases. In order to advance the understanding of the structure and function of these enzymes, the present work intended to study the structure of beta-glucosidases from family GH1 and endoglucanases from family GH5. In the first part of the work, the expression of endoglucanase II from Trichoderma reesei was not achieved, even using different organisms and expression conditions. However, in the second part, the expression, purification and the crystallization first trials of eleven bacterial beta-glucosidases and eight bacterial endoglucanases were achieved. Among them, three beta-glucosidases and one endoglucanase from Bacillus licheniformis were crystallized and had their structures solved. Beta-glucosidases, although having a similar folding, showed variations in the length and position of the loops that form the catalytic cleft and diverge in relation to one of the amino acids that are important in substrate stabilization. These differences may help explain the mechanism of these enzymes to recognize distinct substrates. The endoglucanase, which has two accessory modules, was crystallized in the apo form and complexed with the substrate celotetraose. The second accessory module probably is a cellulose binding domain (CBM) and its aromatic residues, which are responsible for the substrate interaction, seem to complement the catalytic site. Therefore it can be a new mechanism of CBM assistance in the enzymatic activity. The first accessory module has no apparent interaction site with carbohydrates and probably works as a connector between the catalytic domain and CBM. The positioning of the substrate in the binding site is similar to other structures already solved but raises some questions about the role of the catalytic residues, that are conserved in the family. The anomeric carbon of the substrate has a continuous electron density with glutamate from sheet-β4 (which should be the acid/base) and is closer to it than to glutamate from sheet-β7 (which should be the nucleophile).
APA, Harvard, Vancouver, ISO, and other styles
6

Mear, Yves. "Implication de l'activité constitutive du récepteur de la ghréline dans la tumorigenèse des adénomes somatotropes." Thesis, Aix-Marseille, 2013. http://www.theses.fr/2013AIXM5102.

Full text
Abstract:
Les adénomes hypophysaires sont les tumeurs intracérébrales les plus fréquentes. Les adénomes somatotropes hypersécrètent l’hormone de croissance (GH) et sont traités classiquement par des analogues somatostatinergiques. Une petite moitié des patients acromégales est néanmoins résistante à ces traitements. L’on sait depuis, quelques années, que le récepteur de la ghréline possède une forte activité constitutive et joue un rôle majeur dans la sécrétion de GH. Cette activité constitutive est-elle impliquée dans la tumorigenèse des adénomes somatotropes ? Nos travaux ont montré un niveau de transcrits, codant pour le GHS-R, particulièrement élevé dans ces tumeurs, et l’immunocytochimie révèle un marquage punctiforme localisé à la membrane plasmique. La MSP (agoniste inverse du GHS-R) induit une diminution dose-dépendante de la sécrétion de GH des cultures primaires d’adénomes somatotropes. Cette efficacité de la MSP sur la sécrétion de l’hormone de croissance est particulièrement remarquable sur les patients résistants aux agonistes somatostatinergiques chez qui elle démontre une efficacité relative accrue. Des clones, surexprimant le GHS-R humain (lignées MYST-R), ont été générés à partir de lignées somato-lactotropes tumorales de rat (GH4C1). Sur ces cellules, le ligand endogène du GHS-R induit une augmentation d’IP3 intracellulaire. De façon originale, la MSP induit une diminution du niveau d’IP3 intracellulaire. L’inhibition de l’activité constitutive du GHS-R par un agoniste inverse, tel que la MSP, pourrait permettre de réprimer l’hypersécrétion de GH, faisant de cette molécule une alternative pharmacologique aux traitements actuels des adénomes somatotropes
Pituitary tumors are most usual intracranial tumors. The somatotroph adenomas are characterised by a GH hypersecretion. The current treatments are based on somatostatinergic agonists. Unfortunately, there is steel 50% of patients, which remain insensitive to these treatments. The aim of our work was to find a pharmacological alternative to treat the patients resistant to the current therapies. Ghrelin stimulate pituitary GH release in vivo through GHS-R1a activation. Interestingly, this receptor transduces signal through an unusual high constitutive activity. Noteworthy, human somatotroph adenomas expressed a high level of GHS-R1a at both mRNA and protein level. We actually assess the implication of this constitutive activity in the tumorigenesis of the somatotroph adenomas. Firstly we demonstrated GHS-R1a functionality through its capacity to fixe endogenous ligand. Then we showed that treatment of human somatotroph adenomas primary cultures, with the GHS-R1a inverse agonist (MSP: Modified Substance P), induced a dose dependent decrease of GH secretion. To foremost investigate the transduction mechanisms underlying these results, we developed, from GH4C1 (rat somato-lactotroph tumoral cell line), stable monoclonal cell lines overexpressing human GHS-R1a (named MYST-Rg). Interestingly MYST-Rg cells exhibit relatively high basal activation of the IP3 pathway. GHS-R1a endogenous ligand (ghrelin) strengthens basal IP3 pathway activation of MYST-Rg cells. Noteworthy, the basal IP3 pathway activation can be lessened by MSP treatment. Thus, MSP could be a useful alternative to the current therapies of somatotroph adenomas
APA, Harvard, Vancouver, ISO, and other styles
7

Araújo, Juscemácia Nascimento. "Sintese e caracterizacao de nanoparticulas de prata assistidas por B-glicosidases (GH1 e GH3) de Thermotoga petrophila." reponame:Repositório Institucional da UFABC, 2017.

Find full text
Abstract:
Orientador: Prof. Dr. Wanius José Garcia da Silva
Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Biotecnociência, 2017.
A hidrolise enzimatica da celulose e realizada pela acao sinergica de pelo menos tres tipos de celulases distintas: endoglucanases, exoglucanases e B.glicosidases. As endoglucanases e celobiohidrolases sao frequentemente inibidas pelo aumento da concentracao de celobiose (dimero de glicose) no meio reacional. As ¿À-glicosidases sao enzimas que clivam celobiose em monomeros de glicose. Portanto, as B-glicosidases sao essenciais ao processo de hidrolise da celulose por impedirem o acumulo de celobiose e, assim, evitar a diminuicao da taxa de hidrolise. Processos de pre-tratamento da biomassa lignocelulosica sao empregados, antes da reacao de hidrolise enzimatica da celulose, a fim de retirar a fracao de lignina e aumentar a taxa de conversao da celulose em glicose. Porem, estes processos de pre-tratamento da biomassa lignocelulosica nao sao 100% eficientes na remocao da lignina. Estudos previos mostraram que a adicao de lignina a celulose pura pode causar a reducao da liberacao de acucar em valores superiores a 60%. Assim, neste estudo, nos caracterizamos a adsorcao nao produtiva da enzima ¿À-glicosidase da familia GH1 da bacteria Thermotoga petrophila (TpBGL1) em ligninas extraidas de diferentes biomassas (cana-de-acucar e eucalipto). Em pH 7 e 6, nossos resultados indicaram que a repulsao eletrostatica enfraquece a adsorcao nao produtiva de TpBGL1 em ligninas. Contudo, em pH 4 a atracao eletrostatica fortalece a adsorcao nao produtiva. Alem disso, o aumento da temperatura de 25 oC para 70 oC nao resultou em um aumento significativo da adsorcao de TpBGL1 em ligninas, provavelmente porque nao ocorre um aumento significativo de regioes hidrofobicas na estrutura da enzima expostas ao solvente. Todas as informacoes obtidas neste estudo poderao ser uteis para aplicacoes biotecnologicas no campo de conversao de polissacarideos estruturais em bioenergia.
The B-glucosidases are a group of important enzymes employed in a large number of industrial applications. In this study, we reported for the first time the photobiosynthesis of stable and functional silver nanoparticles (AgNPs) using two hyperthermostable bacterial â-glucosidases with industrial potential. The syntheses were simple and rapid processes carried out by mixing â-glucosidases and silver solution under irradiation with light (450-600 nm), therefore, compatible with the green chemistry methodology. The synthesized AgNPs were characterized using a series of physical techniques. Absorption spectroscopy showed a strong absorption band at 460 nm due to surface plasmon resonance of the AgNPs. X-ray diffraction analysis showed that the AgNPs were purely crystalline in nature. Electron microscopy showed AgNPs of variable diameter ranging from 20 to 100 nm. In addition, electron microscopy, zeta potential and Fourier transform infrared spectroscopy results confirmed the presence of â-glucosidases coating and stabilizing the AgNPs. The results also showed that the enzymatic activities were maintained in the â-glucosidases assisted AgNPs. The data described in this study should provide a useful basis for future studies of â-glucosidases assisted AgNPs, including biotechnological applications.
APA, Harvard, Vancouver, ISO, and other styles
8

Kearney, Tara Maria. "The effect of growth hormone replacement (GHR) apolipoprotein B100 (apoB) kinetics in growth hormone deficient (GHD) hypopituitary subjects." Thesis, Imperial College London, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.272425.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Gollapudi, Anantha Srinivasa Babu. "Molecular variants of bovine GH and GHR and their association with milk production traits in Canadian Holstein bulls." Thesis, McGill University, 2001. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=32996.

Full text
Abstract:
In dairy cattle, treatment with exogenous growth hormone (GH) affects growth and function of mammary gland. The actions of GH are mediated via interaction with GH receptors (GHR). The first step in signal transduction is homodimerization of two GHR molecules by GH. This step is critical since mutation in either GH or GHR can block dimerization and thus target cell activation. However, association between milk related traits and combination of GH and GHR variations are not known. Accordingly, DNA genotypes in the GH and GHR genes were investigated for association with milk, fat and protein lactation yields in Holsteins. The marker data were obtained on 873 progeny tested bulls by using PCR-RFLP and PCR-SSCP analysis. There were five markers in GH and three in GHR. Estimated breeding values (EBVs) were obtained from Canadian Dairy Network for milk, fat, and protein lactation yields for the 873 genotyped bulls.
There was significant difference among GH6.1 alleles (C-to-G transversion at position 2141) for the milk yield (P < 0.05) and protein yield (p < 0.05). There were significant differences in GHR AluI (A-to-T transversion at -1182) for milk (p < 0.05) and fat (p < 0.05), and GHR StuI (C-to-T transversion at -232) for fat (p < 0.0001) and protein (p < 0.05). Allele frequencies for GH6.1 (C), GHR AluI (A) and GHR StuI (C) alleles in bulls genotyped were 0.95, 0.63 and 0.95, respectively. Bulls with GH6.1 (C/G) genotype had higher milk EBV (p < 0.05) compared to C/C bulls. Bulls with GHR AluI (A/A) genotype had higher milk EBV (p < 0.01) and fat EBVs (p < 0.05). Bulls with StuI (C/C) genotype had higher fat EBV (p < 0.0001) and protein EBV (p < 0.05) compared to StuI (C/T). This study indicates that the combination of GH and GHR markers could serve as a tool to aid in selection for improving milk, fat, and protein production.
APA, Harvard, Vancouver, ISO, and other styles
10

Jara, Adam. "Growth Hormone (GH) and the Cardiovascular System: Studies in Bovine GH Transgenic and Inducible, Cardiac-Specific GH Receptor Gene Disrupted Mice." Ohio University / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1395792687.

Full text
APA, Harvard, Vancouver, ISO, and other styles
11

Ergueta, Mirko Sime Raljevic. "Estudo da emissão galáctica em 30 Ghz e 41.5 Ghz." Instituto Nacional de Pesquisas Espaciais, 2005. http://urlib.net/sid.inpe.br/MTC-m13@80/2005/10.26.11.35.

Full text
Abstract:
A emissão em microondas da Galáxia é um dos principais contaminantes das medidas da Radiação Cósmica de Fundo em microondas (RCFM). Os modelos usuais prevêem três componentes como fontes desta emissão: síncrotron, livre-livre e poeira. No entanto, há evidências de um excesso de emissão nesta região do espectro que estaria aparentemente correlacionado com poeira e que não pode ser explicado pelos modelos de emissão térmica de grãos. Em razão disso, foi proposto mais um mecanismo para explicar este comportamento anômalo da emissão em microondas da Galáxia. Neste trabalho, exploramos as características das emissões galácticas em microondas e do excesso de emissão observado nessa região do espectro. Para isso, usamos os mapas obtidos pelo experimento BEAST em 30 GHz e 41,5 GHz. Aplicamos uma técnica de correlação cruzada entre os mapas BEAST e mapas de referência para as emissões galácticas com o objetivo de estimar a contribuição de cada componente da emissão galáctica nos mapas BEAST. Avaliamos a distribuição espacial das emissões realizando cortes em diferentes latitudes galácticas. Para estudar a emissão difusa da Galáxia e excluir as regiões do Plano Galáctico, aplicamos aos mapas BEAST a máscara Kp2 utilizada nos dados do WMAP. Associando às emissões leis de potência do tipo \textit{T}$\alpha$$\nu$$^\beta$, obtivemos índices espectrais para cada componente galáctica, Analisamos dois ambientes diferentes: as regiões do Plano Galáctico e as regiões difusas que as envolvem. As características espaciais e espectrais de cada componente obtida indicam que: 1) a emissão síncrotron está concentrada no Plano Galáctico, apresentando um índice espectral $\beta$ = -2,9, consistente com o modelo de geração de elétrons no Plano Galáctico; 2) a emissão livre-livre se localiza nas regiões difusas e no Plano Galáctico, apresentando um índice espectral $\beta$ = -1,3, que é menor que o esperado; 3) a emissão de poeira engloba toda a região do Plano Galáctico, apresentando índices que variam entre -2,2 $\textless$$\beta$$\textless$ -1,4; 4) o excesso de emissão na região difusa segue a distribuição da poeira e o índice espectral associado ($\beta$$\sim$-3) é compatível com a emissão de \textit{spinning-dust}. Quando se inclui o Plano Galáctico, o índice espectral ($\beta$$\sim$-1,5) é compatível com o modelo de \textit{spinning-dust} somado à emissão térmica de poeira.
The Galactic microwave emission is one of the main contaminants of the Cosmic Microwave Background (CMB) Radiation measurements. Three components of this foreground are clearly identified: synchrotron, free-free, and dust emission. However, an excess emission in this frequency range has recently been reported, which is apparently correlated with dust emission, and cannot be explained by the usual thermal dust emission model. Several emission mechanisms have been proposed to explain this anomalous behavior of the Galactic microwave emission, including spinning dust emission. In this work, we explore the characteristics of the Galactic microwave emission at 30 GHz and 41.5 GHz using the BEAST experiment data. We used a cross-correlation technique between BEAST maps and Galactic emission templates in order to estimate the contribution of each Galactic microwave emission component to the BEAST maps. The spatial distribution of these emissions is evaluated through Galactic latitude cuts. In order to analyze the Galactic diffuse emission, we apply the WMAP Kp2 mask to the BEAST maps. We obtain spectral indexes for each Galactic microwave emission component (\textit{T}$\alpha$$\nu$$^\beta$). In our analysis, we consider two different environments: the Galactic Plane region and the diffuse region around the Plane. The spatial and spectral characteristics of the Galactic components indicate that the synchrotron emission is concentrated in the Galactic Plane, with spectral index $\beta$= -2,9, which is consistent with the electrons generation model; the free-free emission is located in the diffuse regions and in the Plane, with spectral index $\beta$ = -1,3, which is smaller than the expected one; and the dust emission is present in all the Plane region, with index that varies between -2,2 $\textless$$\beta$$\textless$ -1,4, which is not explained by the thermal dust emission model. The excess emission follows the dust distribution in the diffuse region, with a spectral index ($\beta$$\sim$ -3), which agrees with spinning-dust emission model. When the Galactic Plane is included, the spectral index ($\beta$$\sim$ -1,5) is compatible with a spinning-dust model plus a thermal dust emission model.
APA, Harvard, Vancouver, ISO, and other styles
12

Rydén, Joakim, and Fabian Sandegård. "Quantification of a Swedish Digitalization Company´s GHG Emission : A Single Case Study." Thesis, KTH, Skolan för industriell teknik och management (ITM), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-279511.

Full text
Abstract:
Research shows that the warming of the climate over the last century is extremely likely due to human activities. Furthermore, there is a need for an understanding how business activities counteract or contribute to climate change. In particular, the digitalization industry is often introduced as an important player in climate challenge. However, research also concludes that the digitalization industry’s impact on the climate is ambiguous, since it in some cases contributes to climate change and in other cases counteracts it. In order to understand the interplay between greenhouse gas emissions and digital solutions, it is necessary to outline and quantify the emissions from particular digitalization projects and furthermore the industry itself. The thesis takes off in a single case study at a Swedish digitalization consultancy company in order to investigate how both internal greenhouse gas emissions and greenhouse gas emissions from customer projects can be quantified as accurate and as often as possible. The findings disclose that greenhouse gas (GHG) emissions can be tracked with an extremely short time step, practically continuously, especially if the tracking is integrated with the company’s ERP1 . Furthermore, the findings show that greenhouse gas emissions from customer projects can be quantified if interpreting and implementing the GHG Protocol with a soft system methodology (SSM) approach. The thesis contributes with (1) a general interpretation of the Corporate Standard (part of the GHG Protocol) in the context of digitalization; (2) a specific example of that interpretation and implementation; (3) a practical interpretation and implementation of the Project Protocol in the context of digitalization and its avoided or caused greenhouse gas emissions; and (4) a general and an in-depth analysis on the topic of quantifying a Swedish digitalization company’s greenhouse gas emissions and feasible approaches to assumption making.
Forskning slår fast att uppvärmningen av klimatet under det senaste århundradet med extremt hög sannolikhet är orsakad av människan. Det finns ett behov att förstå hur affärsverksamheter motverkar eller bidrar till klimatförändringarna. En del av denna affärsverksamheten sker inom digitaliseringsindustrin, vilken ofta presenteras som en central spelare i klimatfrågan. Å andra sidan visar forskning även på en osäkerhet gällande digitaliseringsindustrins påverkan på klimatet eftersom den i vissa fall bidrar till klimatförändringar medan den i andra fall motverkar dem. För att förstå samspelet mellan växthusgasutsläpp och digitala lösningar är det nödvändigt att överskåda och kvantifiera utsläpp från specifika digitaliseringsprojekt och, vidare, från själva industrin. Uppsatsen grundar sig i en fallstudie på ett svenskt digitaliseringskonsultbolag för att undersöka hur både interna utsläpp och utsläpp från kundprojekt kan kvantifieras så precist och så frekvent som möjligt. Resultaten pekar på att växthusgasutsläppen kan spåras och följas med extremt kort tidssteg, i stort sett kontinuerligt, i synnerhet om spårningen kan integreras med företagets affärssystem. Dessutom visar resultaten på att växthusgasutsläpp från kundprojekt kan kvantifieras om GHG Protocol tolkas och implementeras med hjälp av en “soft systems” metod (SSM). Uppsatsen bidrar med (1) en generell tolkning av Corporate Standard (en del av GHG Protocol) i en digitaliseringskontext; (2) ett specifikt exempel på en sådan tolkning och implementering; (3) en praktisk tolkning och implementering av Project Prototcol (en del av GHG Protocol) in en kontext av digitaliseringsbranschen och dess undvikta eller orsakade utsläpp; och (4) en generell och djupgående analys angående kvantifiering av ett svenskt digitaliseringsbolags växthusgasutsläpp och gångbara inställningar till att göra antaganden.
APA, Harvard, Vancouver, ISO, and other styles
13

Young, Jonathan A. "The Effects of Growth Hormone Action on the Mouse Intestine." Ohio University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1534865806561942.

Full text
APA, Harvard, Vancouver, ISO, and other styles
14

Munroe, Brian J. (Brian James). "Experimental studies of novel accelerator structures at 11 GHz and 17 GHz." Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/99298.

Full text
Abstract:
Thesis: Ph. D., Massachusetts Institute of Technology, Department of Physics, 2015.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 181-185).
Photonic band-gap (PBG) structures are promising candidates for electron accelerators capable of high-gradient operation because they have the inherent damping of high order modes required to avoid beam breakup due to instabilities. A key challenge for PBG structures is high-gradient operation without structure damage due to rf-field-induced breakdowns. This thesis reports theoretical results on the design of PBG structures and the generation of wakefields in such structures. It also reports experimental results on PBG structure breakdown testing at high power at both 11 and 17 GHz. A single-cell photonic band-gap (PBG) structure was designed with an inner row of elliptical rods (PBG-E) to reduce ohmic heating relative to a round-rod structure. The PBG-E structure was built and tested at high power at a 60 Hz repetition rate at X-Band (11.424 GHz) at the SLAC accelerator test stand, achieving a gradient of 128 MV/m at a breakdown probability of 3.6 x 10-3 per pulse per meter at a pulse length of 150 ns. The PBG-E structure showed major improvement in breakdown rate relative to a round-rod PBG structure designed at MIT and previously tested at SLAC. A test stand was designed and built at MIT for testing single-cell structures at 17.1 GHz, a frequency 50% higher than the SLAC frequency. This test stand provides comparable diagnostics to those used at SLAC, adding optical diagnostic access which can be used for open PBG structures. A conventional disc-loaded waveguide structure, MIT-DLWG, was tested at MIT at up to a 2 Hz repetition rate. This structure reached a maximum gradient of 87 MV/m at a breakdown probability of 1.19 x 10-1 per pulse per meter. A round-rod PBG structure, MIT-PBG-2, has also been tested at MIT at up to a 2 Hz repetition rate and 100 ns pulse length, demonstrating operation up to 89 MV/rn at a breakdown probability of 1.09 x 10-1 per pulse per meter. These test results show that a PBG structure can simultaneously operate at high gradients and low breakdown probability, while also providing wakefield damping. This makes PBG structures viable candidates for future collider applications.
by Brian J. Munroe.
Ph. D.
APA, Harvard, Vancouver, ISO, and other styles
15

Fossmark, Asbjørn. "Antennediversitet ved 2.4 GHz." Thesis, Norwegian University of Science and Technology, Department of Electronics and Telecommunications, 2008. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-10475.

Full text
Abstract:

De siste årene har det dukket opp stadig nye produkter som inkluderer trådløs bruk. Det er alt fra mobiltelefoner, trådløse hjemmenettverk, pulsmålere og sensorer. For at disse systemene skal bli benyttet er det viktig at den trådløse kommunikasjonen fungerer på en tillitsfull måte. Med så mange nye trådløse produkter som, ofte benytter seg av det samme frekvensområdet, kan det oppstå interferens mellom forskjellige apparater. Da er en måte å løse problemet på å benytte seg av diversitetsteknikker. Denne oppgaven tar utgangspunkt i to spesifikke bruksområder for antennediversitet. En fjernkontroll og et trådløst tastatur som skal benytte seg av to antenner for å potensielt forbedre rekkevidden uten at det går ut over batterilevetid og økonomiske hensyn. Kapittel 2 i denne oppgaven tar for seg teorien rundt antenner og diversitetsløsninger og kapittel 3 tar for seg hvordan simuleringene og målingen er gjennomført. I kapittelene 4 og 5 tar oppgaven for seg resultatene fra simuleringene og målingene som har blitt gjort. Det er også diskutert hva som er årsaken til de resultatene målingene viser. Blant annet hvordan for liten avstand mellom to antenner i en romlig antennediversitet sørger for å forverre egenskapene til applikasjonen. Oppgaven har medført variert arbeid. Det er alt fra simuleringer, fremstilling av antenner, oppkopling i målesituasjoner og behandling av instrumenter og måledata. Det er brukt bilder for å illustrere måleoppsettene.

APA, Harvard, Vancouver, ISO, and other styles
16

Kim, Seungmo. "Coexistence of Wireless Systems for Spectrum Sharing." Diss., Virginia Tech, 2017. http://hdl.handle.net/10919/78625.

Full text
Abstract:
Sharing a band of frequencies in the radio spectrum among multiple wireless systems has emerged as a viable solution for alleviating the severe capacity crunch in next-generation wireless mobile networks such as 5th generation mobile networks (5G). Spectrum sharing can be achieved by enabling multiple wireless systems to coexist in a single spectrum band. In this dissertation, we discuss the following coexistence problems in spectrum bands that have recently been raising notable research interest: 5G and Fixed Satellite Service (FSS) at 27.5-28.35 GHz (28 GHz); 5G and Fixed Service (FS) at 71-76 GHz (70 GHz); vehicular communications and Wi-Fi at 5.85-5.925 GHz (5.9 GHz); and mobile broadband communications and radar at 3.55-3.7 GHz (3.5 GHz). The results presented in each of the aforementioned parts show comprehensively that the coexistence methods help achieve spectrum sharing in each of the bands, and therefore contribute to achieve appreciable increase of bandwidth efficiency. The proposed techniques can contribute to making spectrum sharing a viable solution for the ever evolving capacity demands in the wireless communications landscape.
Ph. D.
APA, Harvard, Vancouver, ISO, and other styles
17

MACHADO, Ana Lúcia Lima. "Determinação das propriedades ópticas do Radiotelescópio GEM em 5 GHz e em 10 GHz." reponame:Repositório Institucional da UNIFEI, 2010. http://repositorio.unifei.edu.br/xmlui/handle/123456789/1426.

Full text
Abstract:
Submitted by repositorio repositorio (repositorio@unifei.edu.br) on 2018-06-28T17:12:49Z No. of bitstreams: 1 dissertacao_0036060.pdf: 7054136 bytes, checksum: 5482998a76470bc5b696229068a80952 (MD5)
Made available in DSpace on 2018-06-28T17:12:49Z (GMT). No. of bitstreams: 1 dissertacao_0036060.pdf: 7054136 bytes, checksum: 5482998a76470bc5b696229068a80952 (MD5) Previous issue date: 2010-02-24
Neste trabalho são apresentadas diversas análises teóricas de desempenho na determinação das propriedades ópticas do radiotelescópio GEM (Galactic Emission Mapping) feitas com auxílio de programas baseados em óptica geométrica e óptica física, bem como a revisão de conceitos teóricos importantes para o desenvolvimento do trabalho. A óptica do radiotelescópio GEM em 5 GHz e em 10 GHz é do tipo Cassegrain, composta por um refletor primário parabólico de 5,5 m e por um refletor secundário de 80 cm. Em 0,408 GHz, 1,465 GHz e 2,3 GHz, a configuração utilizada apresenta apenas o refletor parabólico. A análise da função de alargamento de ponto (Point Spread Function - PSF) mostra que a aberração do sistema é muito pequena. A análise de frente de onda ao longo do eixo óptico mostra que em 5 GHz o erro PV (pico-a-vale) é igual a 8,6 × 10⁻⁴ e que o erro RMS é 2, 3 × 10⁻⁴. Já em 10 GHz, o erro PV é igual a 1,7 × 10⁻ ³ e o erro RMS é 4,6 × 10⁻⁴. Em um plano deslocado de 250 mm do foco, o raio do diagrama de mancha (spot diagram) é de 49 mm, ao passo que o raio do disco de Airy nessa mesma posição é de 137 mm em 5 GHz e de 69 mm em 10 GHz. Estes resultados serão usados no projeto do receptor do GEM em 10 GHz, que será sensível em intensidade total e polarização.
APA, Harvard, Vancouver, ISO, and other styles
18

Masetti, Mattia. "Analisi e valutazione delle proprietà termiche dello speciale trattamento di anodizzazione G.H.A." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2016. http://amslaurea.unibo.it/11804/.

Full text
Abstract:
L'argomento principale di questo elaborato è l'analisi delle proprietà termiche del G.H.A .(Golden Hard Anodizing), ovvero un particolare trattamento di trasformazione superficiale dell'alluminio. Nello specifico è stato studiato tramite confronto con la conducibilità termica, la diffusività e l’emissività termica. Per ottenere tali dati sono state svolte prove sperimentali in modo da avere un chiara visione dell'entità di tali proprietà e metterle a confronto con quelle dell'alluminio base e dell'alluminio anodizzato.
APA, Harvard, Vancouver, ISO, and other styles
19

Hagen, Morten. "Doherty effektforsterker for 1,8 GHz." Thesis, Norwegian University of Science and Technology, Department of Electronics and Telecommunications, 2007. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-10377.

Full text
Abstract:

Formålet med denne oppgaven er å designe en Dohertyforsterker. En klasse AB og en klasse C effektforsterker til bruk i denne konfigurasjonen skal designes, simuleres og gjøres målinger på hver for seg. Disse skal så å bli satt sammen til en Dohertyforsterker som skal simuleres og gjøres målinger på. Dohertyforsterkeren skal ha en senterfrekvens på 1.8 GHz og være tilpasset slik at det oppnås best PAE og linearitet. Rapporten omhandler i de første kapitlene litt generell forsterkerteori med hovedtrykk på Dohertykonfigurasjonen og hva som er viktig og tenke på når denne designes. Fordelen med en Dohertyeffektforsterker er at den forbedrer effektiviteten over et større dynamisk område. Dette er spesielt viktig for modulerte signaler som ikke har konstant envelope. Den viktigste delen er design, simulering og praktisk måling av effektforsterkerne som hører med i Dohertykonfigurasjonen. Designet av effektforsterkerene er utført med et designverktøy som heter ADS, Advanced Design Systems. For å designe effektforsterkerene med hensyn på best PAE og linearitet ble det benytte ferdiglagde prosjekter i ADS som fant tilpasningsimpedansene som måtte til for å oppnå dette. Transistorvalget falt på en transistor fra Eudyna som heter FLL120MK. Dette valget ble gjort etter mye testing av en annen transistor, som det viste seg ikke kunne brukes fordi den ikkelineære modellen i ADS var utilstrekkelig. Et firma i Florida hadde en storsignalmodell for denne transistoren som det var mulig å få en lisens til, som kunne brukes under masteroppgaven. En ikkelineær simulering av forsterkerne ble utført i ADS og viktige parametere som karakteriserer forsterkerene er P1dB, gain og PAE. For klasse AB forsterkeren ble $P1dB=19dBm$ inneffekt, $Gain_{P1dB}=9.5 dBm$ og $PAE_{P1dB}=36.7%$. Klasse C forsterkeren ble designet for å være i en Dohertykonfigurasjon og hadde et påslagspunkt på 19 dBm, $Gain_{maks}=9.1 dBm$ og maks PAE på 46% . Disse to forsterkerene ble satt sammen til en Dohertykonfigurasjon som fikk $P1dB=29 dBm$ inneffekt, $Gain_{P1dB}=7.1 dBm$ og $PAE_{P1dB}=48.5%$. For å sammenligne en Doherty og en klasse AB forsterker, er PAE i 6 dB backoff punktet som teller. Forbedringen ble på 20%. Lineariteten i Doherty forsterkeren er meget bra og P1dB økte med 9.5dBm. Gainet hadde gått ned 2.5 dBm, som er en ulempe med Dohertykonfigurasjonen og stemmer bra med teorien. Målingene viste at klasse AB forsterkeren fikk et $P1dB=23 dBm$ inneffekt, $Gain_{P1dB}=5.88$ og $PAE_{P1dB}=35%$. En forskjell på 3 dBm i forhold til klasse AB simuleringene. PAE fikk samme verdi som i simuleringene. Klasse C forsterkeren hadde oscillasjoner ved 160 MHz. Dette fulgte med på Dohertyforsterkeren som hadde samme type oscillasjoner da klasse C forsterkeren begynte å lede. Transistormodellen i ADS er veldig nær opp til den praktiske transistoren, men har ustabilitetsegenskaper som ikke kom fra under simuleringene. Biaseringen og stabilitetsnettverket har skylden i at det ikke ble en stabil klasse C-forsterker.

APA, Harvard, Vancouver, ISO, and other styles
20

Todorovic, Magdolna. "CMB foregrounds at 33 GHz." Thesis, University of Manchester, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.498967.

Full text
APA, Harvard, Vancouver, ISO, and other styles
21

Opletal, Prokop. "Duplexer pro pásmo 5,6 GHz." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2011. http://www.nusl.cz/ntk/nusl-219142.

Full text
Abstract:
The aim of this master’s theses was a designing of duplexer working in non license frequency band 5.6GHz. The theses is concerning with selection of suitable concept for a given duplexer, with creating a model in software for simulation of distribution of electromagnetic field and with subsequent implementation of duplexer and verifying its parameters.
APA, Harvard, Vancouver, ISO, and other styles
22

Hawbaker, Dwayne Allen. "Indoor wide band radio wave propagation measurements and models at 1.3 ghz and 4.0 ghz /." This resource online, 1989. http://scholar.lib.vt.edu/theses/available/etd-08182009-040436/.

Full text
APA, Harvard, Vancouver, ISO, and other styles
23

BARRETO, EDUARDO PAES. "PROPAGATION LOSS MEASUREMENTS AND MODELING IN AN URBAN REGION AT 2,5 GHZ AND 3,5 GHZ." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2013. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=35314@1.

Full text
Abstract:
PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO
COORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR
PROGRAMA DE EXCELENCIA ACADEMICA
A busca constante pela melhoria dos meios de comunicação em banda larga demandou o surgimento de novas tecnologias visando atender a real necessidade de seus usuários. O uso de mobilidade no acesso à internet banda larga como propõem os padrões WiMAX e LTE, impõe a necessidade de se estudar com mais profundidade os parâmetros que caracterizam um canal rádio móvel. Este trabalho objetiva apresentar os resultados experimentais que permitem caracterizar em banda estreita o comportamento do canal de radiopropagação num ambiente urbano. Como resultado das campanhas de medições, são identificados modelos do canal que possibilita ao projetista definir os melhores critérios para a implantação de uma rede móvel de acesso sem fio. Desta forma, são apresentadas duas campanhas de medições, operando nas frequências de 2,5 GHz e 3,5 GHz, destinadas para novos serviços móveis banda larga.
The constant search for improvement of broadband communication systems requires new technologies to attend the increasing needs of the users. The use of mobility in broadband Internet access as proposed in WiMAX and LTE standards, imposes the need to further understand the parameters that characterize a channel mobile radio. This dissertation presents experimental results that allow characterizing the narrow band channel behavior of radio propagation in an urban environment. As a result of measurement campaigns, channel models are identified which allow the designer to define the best criteria to implement a mobile wireless network. The work presents results of two measurement campaigns, at the frequencies of 2.5 GHz and 3.5 GHz, designed for new mobile broadband services.
APA, Harvard, Vancouver, ISO, and other styles
24

Rahman, Arifur 1970. "Room temperature micromachined microbolometers for W-band (75 GHz-110 GHz) focal plane imaging array." Thesis, Massachusetts Institute of Technology, 1996. http://hdl.handle.net/1721.1/38847.

Full text
APA, Harvard, Vancouver, ISO, and other styles
25

Hawbaker, Dwayne Allen. "Indoor wide band radio wave propagation measurements and models at 1.3 ghz and 4.0 ghz." Thesis, Virginia Tech, 1991. http://hdl.handle.net/10919/44287.

Full text
Abstract:
An extensive radio wave propagation measurement campaign was conducted at 1.3 GHz and 4.0 GHz inside four buildings, including a sports arena, a modern closed-plan office building, and two dissimilar, open-plan factories. Measurements were recorded at 57 locations using base station antenna heights of 1.7 meters and 4.0 meters. Results were obtained for mean and maximum excess delay, rms delay spread, time delay jitter, differential delay jitter, and path loss through analyses of impulse response estimates, which were obtained via repetitive 5 ns probing pulses. The effects of frequency, antenna height, topography (line-of-sight or obstructed direct path), and building environment on delay spread and path loss are quantified. Results indicate that, on average, the frequencies and antenna heights used in this study have minimal impact on rms delay spread and path loss. However, topography and building environment significantly affect these parameters. RMS delay spread values as high as 230 ns were observed in open plan factories. Computed path loss power law exponents are 1.84 and 2.35 for line-of-sight and obstructed topographies, respectively. A second campaign was conducted to determine the effects of antenna directivity and polarization on propagation parameters. On average, line-of-sight indoor channels offer 8 dB of cross-polarization discrimination, whereas obstructed environments offer less than 3 dB. Directional antennas provide a significant reduction in rms delay spread over omni-directional antennas. In line-of-sight environments, circular polarization provides an additional delay spread reduction.
Master of Science
APA, Harvard, Vancouver, ISO, and other styles
26

Martinez, Jean-François. "Etude du fonctionnement d'aquifères complexes, pays de Gex, Ain." Grenoble 1, 1986. http://www.theses.fr/1986GRE10070.

Full text
APA, Harvard, Vancouver, ISO, and other styles
27

Bejjit, Lahcen. "Etude par RPE, à 10 et 35 GHz, des propriétés magnétiques du supraconducteur à haute Tc Y1-x Gdx Ba2 Cu3 O7 monocristallin ou fritté :effetd'un recuit sur les propriétés magnétiques." Aix-Marseille 1, 1992. http://www.theses.fr/1992AIX11025.

Full text
Abstract:
Nous avons etudie par rpe, a 10 et 35 ghz, dans la gamme de temperatures 4,2-300 k, les proprietes magnetiques du supraconducteur a haute t#c y#1##xgd#xba#2cu#3o#7 (avec 2. 10##4x1). Pour les mesures de rpe a 35 ghz et a basse temperature, nous avons realise une cavite et les equipements peripheriques. Les spectres rpe obtenus, dans gdba#2cu#3o#7, sont souvent deformes par l'effet de peau et par la raie dite a. La largeur de la raie rpe depend du mode de preparation des echantillons. La raie intrinseque est une lorentzienne (g=2. 010. 01), ce qui suggere l'existence d'un retrecissement par echange. Le calcul theorique et l'experience montrent que, dans gdba#2cu#3o#7, les ions gd#3#+ sont couples a la fois par le couplage dipolaire et par l'echange. Le couplage d'echange n'est assure ni par les electrons de conduction ni par des oxygenes. C'est probablement un couplage direct ou un superechange via des ions autres que les oxygenes. Nous avons obtenu pour la constante d'echange entre ions gd#3#+ plus proches voisins 2j/k=0. 33k. A t
APA, Harvard, Vancouver, ISO, and other styles
28

Blayo, Anne-Laure. "Conception et synthèse d'antagonistes du récepteur de la ghréline basés sur le motif 1,2,4-triazole 3,4,5-trisubstitué." Thesis, Montpellier 2, 2010. http://www.theses.fr/2010MON20041.

Full text
Abstract:
La ghréline, une hormone peptidique principalement synthétisée au niveau de l'estomac, est le ligand endogène du récepteur des sécrétagogues de l'hormone de croissance appelé GHS-R1a. Elle est impliquée dans de nombreux processus biologiques dont principalement la sécrétion de l'hormone de croissance et la régulation de l'homéostasie énergétique. En raison de ses propriétés orexigènes et adipogènes, la ghréline est un outil puissant pour lutter contre les déséquilibres énergétiques. Développer des antagonistes de son récepteur représente ainsi une stratégie prometteuse pour la découverte de nouvelles pharmacothérapies contre l'obésité.Cette thèse est consacrée au développement d'antagonistes du récepteur de la ghréline dont la structure est basée sur une plateforme peptidomimétique : le 1,2,4-triazole 3,4,5-trisubstitué. Notre objectif est de concilier au mieux l'affinité et l'activité de nos ligands vis-à-vis du GHS-R1a avec des propriétés optimisées permettant de favoriser une bonne biodisponibilité orale. Nous nous sommes basés sur une synthèse rapide et efficace de ces composés pour réaliser des études approfondies de relations structure-activité et structure-propriété. En optimisant successivement les différentes positions autour du motif triazole, des compromis intéressants ont été obtenus. Nous avons ainsi identifié des antagonistes affins du récepteur qui présentent une stabilité microsomale suffisante et une perméabilité membranaire satisfaisante pour envisager des études in vivo
Ghrelin, a peptidic hormone which is mainly synthesized in the stomach, is the endogenous ligand of the growth hormone secretagogue receptor named GHS-R1a. It is involved in numerous biological processes such as the growth hormone secretion and the control of energy homeostasis. Because of its orexigenic and adipogenic properties, ghrelin is a potent tool to control energy imbalance. Developing ghrelin receptor antagonists represents a promising strategy for the discovery of anti-obesity new drugs.This thesis is devoted to the development of ghrelin receptor antagonists based on a peptidomimetic scaffold: the 3,4,5-trisubstituted 1,2,4-triazole. Our aim is to combine ligand affinity and activity towards GHS-R1a with optimized properties which enable to promote a good oral bioavailability. We based our work on a rapid and efficient synthesis of our compounds to carry out detailed structure-activity and structure-property studies. By successively optimizing the different positions around the triazole scaffold, interesting compounds were obtained. We have thus identified receptor antagonists which exhibit sufficient microsomal stability and satisfactory membrane permeability to consider in vivo studies
APA, Harvard, Vancouver, ISO, and other styles
29

Moneró, Tatiana Oliveira. "Aplicação do GHS na indústria de saneantes: roteiro para classificação de produtos saneantes." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/6/6139/tde-20012017-121652/.

Full text
Abstract:
Com o aumento gradativo da tecnologia e da necessidade de consumo humana, a cada dia são desenvolvidos novos produtos e novas substâncias. Além dos benefícios desta modernização, surgem as preocupações relacionadas com o uso excessivo de produtos químicos. Muitos produtos químicos possuem potencial de causar efeitos adversos à saúde humana e ao meio ambiente e, por isso, de uns anos pra cá, passou a ser essencial e obrigatória a comunicação dos riscos advindos desses produtos dentro do ambiente de trabalho. O GHS, um sistema globalmente harmonizado de classificação e rotulagem de produtos químicos foi criado pela ONU para trazer critérios e elementos harmonizados para a comunicação desses perigos. A identificação dos perígos do GHS é um procedimento complexo e muito difícil para as empresas, com destaque para aquelas de menor porte, como é o exemplo do setor de saneantes, que é, em sua maioria, constituido por micro e pequenas empresas. Além de terem a obrigação de seguir os requisitos estabelecidos pelo GHS, os fabricantes de saneantes seguem as exigências da Anivsa para comercialização de seus produtos. Combinando os requisitos da Anvisa com os do GHS, percebe-se que algumas classes e categorias de perigo do GHS não se aplicam para saneantes. Com isso, o propósito desse trabalho foi desenvolver um roteiro para classificação do GHS destinado especificamente ao setor de saneantes. Para o desenvolvimento do roteiro foram elaborados fluxogramas de decisões lógicas com requisitos do GHS e exigências da Anvisa. O trabalho atingiu o seu objetivo como um todo, criando um modelo de roteiro para aplicação do GHS para o setor de saneantes. Após a aplicação do roteiro em um produto exemplo e após as discussões levantadas, percebeu-se que alguns detalhes poderiam ser melhor incorporados no roteiro. Apesar do roteiro possuir suas limitações e algumas imperfeições, acredita-se que possa contribuir de alguma forma para o setor. Ao invés dos profissionais consultarem o GHS como um todo, um guia simplificado, resumido e com particularidades do setor, pode fazer com que as indústrias tenham uma maneira mais fácil de aplicar o GHS e, assim, contribuir para que as classificações sejam realizadas de uma maneira correta.
With the technology gradual increase and the need of human consumption every day new products and new substances are developed. In addition to the benefits of this modernization, there are concerns about the excessive use of chemicals. Many chemicals have potential to cause adverse effects on human health and the environment and, therefore, a few years ago the risk communication of these products in a workplace became essential and mandatory. The GHS, a globally harmonized system of classification and labeling of chemicals was created by the UN to bring harmonized criteria and elements to communicate these dangers. The GHS hazard identification is a complex and difficult procedure for the industries, especially those ones that are small, as sanitizer sector for example, which is mostly composed of micro and small companies. In addition to have the GHS obligation the sanitizer manufacturers follow the Anvisa regulation as well. Combining the Anvisa requirements with GHS ones, it is clear that some GHS hazard classes and categories do not apply for cleaning products. Thus, the purpose of this study was to develop a GHS classification guide intended specifically for sanitizer industry. To build the guide flowcharts were developed with logical decisions with GHS and Anvisa requirements. This study reached its goal as a whole, creating a guide model for GHS implementation in sanitizer industries. After the guide application in a product sample and the discussions, it was noted that some details could be better incorporated into the script of the guide. Although the guide has some limitations and imperfections, it can contribute in some way to the industry. Instead of a professional consulting GHS as a whole, a simplified, summarized and with the sanitizer particularities guide may give to the industries an easier way to apply the GHS contributing to the correct classifications.
APA, Harvard, Vancouver, ISO, and other styles
30

Stefanello, Sílvio Terra. "AVALIAÇÃO DA CAPACIDADE ANTIOXIDANTE IN VITRO DE NOVOS COMPOSTOS MONO E DISSELENETO." Universidade Federal de Santa Maria, 2013. http://repositorio.ufsm.br/handle/1/11215.

Full text
Abstract:
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
The antioxidant action of organic selenium compounds, as well as ebselen and diphenyl diselenide (DPDS), is closely connected to its ability of generating the selenol group. (In) this study it was evaluated the in vitro antioxidant effect of new mono and diselenide compounds, where it was compared whether the formation of p-methyl-selenol from compounds 1-phenyl-3-(p-tolylselanyl)propan-2-amine (C1) and 1,2-dip-tolyldiselenide (C4) and o-methoxy-selenol from compounds 1-(2-methoxyphenylselanyl)-3-phenylpropan-2-amine (C2) and 1,2-bis(2-methoxyphenyl) diselenide (C3) may be involved with their antioxidant effects. The mono and diselenide compounds were tested in their Fe(II) and sodium nitroprusside (SNP)-induced lipid peroxidation in rat brain and liver homogenates and also in their antioxidant ability in phosphomolybdenum test-reductionand and DPPH radical. Besides, the effects of the compounds in the antioxidant enzymes thioredoxin reductase (TrxR) and glutathione peroxidase (GPx) were quantified. The new compounds oxidant effects were investigated through the thiol oxidase assay and the cellular viability of isolated leukocytes. The results demonstrated that the compounds obtained a significant reduce on the lipid peroxidation induced by different pro-oxidants, as well as an antioxidant effect similarly when compared to ascorbic acid equivalents. In the same manner, the compounds did not present thiol oxidase activity. Furthermore, they did not preset any decrease on the cellular viability of leucocytes. The compounds C1 and C2 did not show mimetic activity of GPx enzyme or had a substrate effect on TrxR enzyme, probably due the amino group presence on their chemical structures which must have inhibited the selenol formation. However, DPDS analog-compounds presented a mimetic activity of GPx, as well as they showed an increase in the TrxR activity, presumably due the formation of the selenol groups (p-methyl-selenol and o-methoxy-selenol).
A ação antioxidante dos compostos orgânicos de selênio, como o ebselen e o disseleneto de difenila (DPDS), está intimamente envolvida com a capacidade de formação do grupamento selenol. Neste estudo foi avaliado o perfil antioxidante in vitro de novos compostos mono e disseleneto, onde foi comparado se a formação do p-metil-selenol pelos compostos 1-fenil-3-(p-tolilselenil)propano-2-amina (C1) e o 1,2-dip-tolildisseleneto (C4), assim como a formação do grupamento o-metoxi-selenol pelos compostos 1-(2-metoxifenilselenil)-3-fenilpropano-2-amina (C2) e 1,2-bis(2-metoxifenil)disseleneto (C3) pode estar associados com os efeitos antioxidantes apresentados. Os novos compostos mono e disseleneto foram avaliados quanto a capacidade de redução dos níveis de peroxidação lipídica induzida por Fe(II) e nitroprussiato de sódio em homogenatos de cérebro e fígado de ratos, assim como também foi avaliada a capacidade antioxidante através do ensaio da redução do fosfomolibdênio e do radical DPPH. Além disso, foram quantificados os efeitos dos compostos quanto à atividade das enzimas antioxidantes, tioredoxina redutase (TrxR) e glutationa peroxidase (GPx). O efeito oxidante, dos novos compostos, foi investigado através do ensaio da tiol oxidase e da viabilidade celular de leucócitos isolados. Decorrente dos resultados obtidos foi possível evidenciar que ambos os compostos apresentaram uma redução significativa da peroxidação lipídica quando induzidas por diferentes pro oxidantes assim como, uma capacidade antioxidante total semelhante a equivalentes de acido ascórbico. Da mesma forma, os compostos não apresentaram efeito tiol oxidase, assim como não apresentaram uma diminuição da viabilidade celular de leucócitos. Os compostos C1 e C2 não apresentaram atividade mimética a enzima GPx assim como, também não serviram de substrato para a enzima TrxR, provavelmente devido a presença do grupamento amino nas estruturas químicas destas moléculas o que incapacitou a formação dos respectivos grupamentos selenois. No entanto, os compostos análogos ao DPDS apresentaram atividades miméticas a GPx, assim como também apresentaram uma aumento na atividade da TrxR provavelmente devido a formação dos selenois (p-metil-selenol e o-metoxi-selenol).
APA, Harvard, Vancouver, ISO, and other styles
31

Strauss, Juergen. "Erweiterung der Benutzeroberflaeche fuer GEX/UX." Thesis, Universitätsbibliothek Chemnitz, 1997. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-199700070.

Full text
APA, Harvard, Vancouver, ISO, and other styles
32

Strauss, Jürgen. "Erweiterung der Benutzeroberflaeche für GEX/UX." [S.l. : s.n.], 1997. http://www.bsz-bw.de/cgi-bin/xvms.cgi?SWB10324511.

Full text
APA, Harvard, Vancouver, ISO, and other styles
33

Hu, Wen 1968. "Studies of novel 140 GHz gyrotrons." Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/42764.

Full text
APA, Harvard, Vancouver, ISO, and other styles
34

Johnston, William F. (William Francis). "A low dispersion 2-GHz comparator." Thesis, Massachusetts Institute of Technology, 2001. http://hdl.handle.net/1721.1/36781.

Full text
Abstract:
Thesis (M. Eng. and S.B.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2001.
Includes bibliographical references (leaves 40-41).
A low dispersion 2-GHz comparator is an essential part of the latest automated VLSI tester by Teradyne Inc. With each new and faster CMOS logic VLSI microchips, faster and more precise comparators are needed to verify that the static discipline is being met on the many pins of the integrated circuit. As the error in the comparator is lowered, the VLSI production yield is greatly increased because of greater certainty of the measurements. The comparator described within is designed to test a variety of CMOS logic levels at the expected logic levels and rise-times of the near future. The result is a Si-Ge integrated comparator with 12psec of dispersion by detailed simulation awaiting fabrication. Index Terms-Complementary metal oxide semiconductor transistor technology (CMOS technology), very large scale integration (VLSI), application specific integrated circuit (ASIC), silicon germanium (Si-Ge), integrated circuits (IC), automatic test equipment (ATE), personal computer (PC), digital signal processing (DSP), direct current (DC), alternating current (AC), device under test (DUT), pin electronics (PE), bipolar junction transistors (BJT), complementary metal oxide semiconductor field effect transistor (MOSFET).
by William F. Johnston.
M.Eng.and S.B.
APA, Harvard, Vancouver, ISO, and other styles
35

Hamadallah, Mazen. "Antenne réseau cylindrique à 32 GHz." Nice, 1990. http://www.theses.fr/1990NICE4423.

Full text
Abstract:
On présente l'étude et la réalisation d'une antenne réseau cylindrique directive à 32 GHz. Une approximation simple, dite approximation plane, est développée pour dimensionner le réseau. On démontre la médiocrité d'une solution utilisant la technologie guides à fentes axiales sur le cylindre. Un mode d'alimentation, dite mode simultané, est introduit afin de simplifier le circuit d'alimentation. On démontre sa validité dans le cas d'une réalisation en technologie microruban. Le diagramme d'un élément microruban incliné de 45° sur un cylindre est calculé en utilisant le modelé de la cavité. Le logiciel d'analyse développé est validé par une réalisation d'un réseau cylindre à 12 GHz. Les limitations de 4 types de diviseurs de puissance en technologie microruban sont examinées à travers plusieurs réalisations pratiques. Le réseau cylindrique réalisé à 32 GHz est mesuré et comparé au calcul. Les performances obtenues sont globalement satisfaisantes et quelques axes d'améliorations possibles sont donnés. Une retombée indirecte de cette thèse a été le développement d'une méthode précise pour l'analyse large bande des réseaux plans en guides à fentes
APA, Harvard, Vancouver, ISO, and other styles
36

Levocký, Kristián. "Všesměrová anténa pro pásmo 60 GHz." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2021. http://www.nusl.cz/ntk/nusl-442415.

Full text
Abstract:
This thesis deals with brief research on problematics of antennas in microwave band for omni-directional applications, own design and assembling of such an antenna. The purpose of the design is to have a best possible radiation patterns and reflection loss of our antenna. Conical monopole is chosen and it is simulated and changed to get the best possible parameters. Two prototypes are manufactured with mechanical changes applied and their parameters measured. Finished antenna is used for experimental channel measurement.
APA, Harvard, Vancouver, ISO, and other styles
37

Hebelka, Vladimír. "Panelové antény pro pásmo 5,6 GHz." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2011. http://www.nusl.cz/ntk/nusl-219127.

Full text
Abstract:
This thesis is focused on the design of panel antennas for band 5,6 GHz. Antennas have been examined and optimized with a view to impedance, broadband and directional characteristics by using designing software CST Design Environment. Optimized antennas were produced, and their measured parameters achieved required values.
APA, Harvard, Vancouver, ISO, and other styles
38

Aitha, Venkat Ramana, and Mohammad Kawsar Imam. "Low Noise Amplifier for radio telescope at 1 : 42 GHz." Thesis, Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-997.

Full text
Abstract:

This is a part of the project “Radio telescope system” working at 1.42 GHz, which includes designing of patch antenna and LNA. The main objective of this thesis is to design a two stage low noise amplifier for a radio telescope system, working at the frequency 1.42 GHz. Finally our aim is to design a two stage LNA, match, connect and test together with patch antenna to reduce

the system complexity and signal loss.

The requirements to design a two stage low noise amplifier (LNA) were well studied, topics including RF basic theory, layout and fabrication of RF circuits. A number of tools are available to design and simulate low noise amplifiers but our simulation work was done using advanced design system (ADS 2004 A). The design process includes selection of a proper device, stability check of the device, biasing, designing of matching networks and layout of total design and fabrication. A lot of time has been

spent on designing of impedance matching network, fabrication and testing of the design circuits and finally a two stage low noise amplifier (LNA) was designed. After the fabrication work, the circuits were tested by the spectrum analyzer in between 9 KHz to 25 GHz frequency range. Finally the resulting noise figure 0.299 dB and gain 24.25 dB are obtained from the simulation.

While measuring the values from the fabricated circuit board, we found that bias point is not stable due to self oscillations in the amplifier stages at lower frequencies like 149 MHz for first stage and 355 MHz for second stage.

APA, Harvard, Vancouver, ISO, and other styles
39

Vincent, Tracey S. "TRANSMISSION LINE FEATURES AND THEIR INFLUENCE ON GHz CONDUCTOR LOSS." Digital WPI, 2009. https://digitalcommons.wpi.edu/etd-dissertations/302.

Full text
Abstract:
"Transmission loss needs to be considered in the design of telecommunication systems. If telecommunication systems have high transmission loss, the signals lose too much of their strength, which results in poor reception in television networks and lost calls in cellular networks. Total transmission loss, in the MHz-GHz range, has several different loss components, some of which are poorly characterized. Conductor loss is the largest loss component and the most difficult to predict. It is known that the conductor geometry or features influences the conductor loss. However, current numerical, analytical and empirical tools do not accurately predict this loss component, and there is little experimental data available to explain and show the impact of these conductor geometries. The conductor shape is heavily influenced by the ceramic substrate surface roughness, and this is especially true for printed circuit boards fabricated with thick-film technology. The two conductor features of interest are the conductor-edge angle and conductor-ceramic interface. For thick-film circuits, the edge of the conductor does not have a square cross section but has a tapered shape or angle. The conductor-ceramic interface is also rough at the micron scale. Since the current density is concentrated at the extremities of the conductor then these features, conductor-ceramic interface and conductor edges, can potentially have a large impact on conductor loss. For this study, the surfaces of ceramic substrates were subjected to different surface finishes that resulted in distinctly different surface characteristics. This in turn resulted in a range of conductor-ceramic interfaces and conductor-edge angle geometries. The impact of the conductor-edge angle and conductor-ceramic interface features on conductor loss was measured over a range of frequencies and conductor conductivities to ascertain the level of their contribution. It was shown quantitatively that the conductor-edge angle was significantly altered by the surface roughness and heavily influenced the conductor loss result. The consensus for decades has been that greater surface roughness causes the ceramic-conductor interface geometry to have a greater impact on conductor loss, increasing the conductor loss. However, this study has shown that greater surface roughness also causes the conductor-edge angle feature to have a smaller or reduced impact on conductor loss, improving the conductor loss result - this has not been considered previously. Focusing on only one of these features can give an anomalous loss prediction; both features need to be considered for the calculation of conductor loss for thick-film applications. The low frequency loss results are as expected but the high frequency (greater than 5GHz) results depend on edge angle and therefore thick-film paste viscosity, and substrate surface roughness. "
APA, Harvard, Vancouver, ISO, and other styles
40

Liu, Gang [Verfasser]. "A 60 GHz, multi-Gbps down-converter IC in an 80 GHz fT SiGe technology / Gang Liu." Ulm : Universität Ulm. Fakultät für Ingenieurwissenschaften und Informatik, 2012. http://d-nb.info/1028033605/34.

Full text
APA, Harvard, Vancouver, ISO, and other styles
41

Ravachol, Julie. "Rôle des glycosides hydrolases de famille 9 dans la dégradation de la cellulose et exploration du catabolisme de xyloglucane chez Ruminiclostridium cellulolyticum." Thesis, Aix-Marseille, 2015. http://www.theses.fr/2015AIXM4054.

Full text
Abstract:
R. cellulolyticum est une bactérie mésophile, anaérobie stricte et cellulolytique, qui sécrète des macro-complexes multienzymatiques (cellulosomes) très performants dans la dégradation des polysaccharides de la paroi végétale. Les Glycoside Hydrolases de famille 9 (GH9) sont toujours surreprésentées chez les bactéries à cellulosomes. Le génome de R. cellulolyticum code 13 GH9 dont 12 participent aux cellulosomes. Mon travail de thèse a consisté à étudier l’ensemble des GH9 de R. cellulolyticum, en déterminant leurs activités à l’état libre et en complexes, afin d’élucider leurs rôles dans la dégradation de la cellulose. Les GH9 ont chacune des activités et des spécificités de substrats différentes. Deux GH9 présentent des activités atypiques, puisque l’une d’elles est inactive et l’autre est une xyloglucanase. Les caractérisations en complexes ont souligné l’importance de la diversité des GH9 et ont montré qu’elles agissent en synergie dans la dégradation de la cellulose. De plus, l’élargissement du panel des GH9 de R. cellulolyticum par l’introduction d’une cellulase exogène de Lachnoclostridium phytofermentans a permis d’améliorer les capacités cellulolytiques de la clostridie. L’activité xyloglucanase d’une des GH9 m’a poussé à étudier le catabolisme du xyloglucane chez R. cellulolyticum. Ce travail a mis en exergue la présence d’un équipement spécialisé dans l’utilisation de ce sucre. Ainsi, après une dégradation du xyloglucane par les enzymes cellulosomales en xyloglucane dextrines, ces dernières sont importées dans le cytoplasme par un transporteur ABC spécifique puis hydrolysées séquentiellement par les enzymes cytoplasmiques en mono et disaccharides assimilables
Ruminiclostridium cellulolyticum is a mesophilic and strictly anaerobic bacterium. It produces multienzymatic complexes called cellulosomes which efficiently degrade the plant cell wall polysaccharides. Family-9 Glycoside Hydrolases (GH9) are plethoric in cellulosome-producing bacteria. The genome of R. cellulolyticum thus encodes for 13 GH9 enzymes, 12 of them participate to the cellulosomes.My Ph. D. aimed at characterizing all GH9 enzymes from R. cellulolyticum, by determining their activities in a free and complexed states, in order to elucidate their role in cellulose degradation. All GH9 enzymes exhibit various activities and substrate specificities. Two of them have atypical activities, since one is inactive and one is a xyloglucanase. Results obtained when all GH9 are in complex highlighted the importance of GH9 diversity and revealed they act synergistically in cellulose depolymerization. Moreover, expanding the panel of GH9 enzymes by introducing an exogenous cellulase from Lachnoclostridium phytofermentans improved the cellulolytic capacities of R. cellulolyticum. The xyloglucanase activity of one GH9 enzyme prompted me to investigate the xyloglucan catabolism in R. cellulolyticum. This work uncovered the presence of a specialized equipment for xyloglucan utilization. After extracellular digestion of xyloglucan by cellulosomal enzymes, xyloglucan dextrins are imported into the cytoplasm via a specific ABC-transporter and sequentially hydrolyzed by cytoplasmic enzymes into fermentable mono and disaccharides
APA, Harvard, Vancouver, ISO, and other styles
42

Melo, Yugo Lima. "Peroxidase de glutationa mitocondrial de arroz à crucial para o crescimento por favorecer a fotossÃntese." Universidade Federal do CearÃ, 2014. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=12121.

Full text
Abstract:
CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior
O papel fisiolÃgico das peroxidases de glutationa (GPX) da mitocÃndria em plantas à muito pouco conhecido. Suas relaÃÃes com a fotossÃntese sÃo desconhecidas, ainda mais na presenÃa de estresse salino. Essa enzima possui grande importÃncia na remoÃÃo de H2O2 e hidroperÃxidos orgÃnicos, contribuindo na proteÃÃo oxidativa e na homeostase redox. Neste estudo, mutantes de arroz silenciados nos genes OsGPX1 ou OsGPX3, das proteÃnas mitocondriais, foram utilizados para entender os mecanismos fisiolÃgicos do papel dessa enzima no crescimento e fotossÃntese. Adicionalmente, estes processos foram estudados tambÃm em condiÃÃes de estresse salino para as plantas silenciadas em OsGPX1. Os resultados mostram, pela primeira vez, que a deficiÃncia de uma GPX mitocondrial à capaz de restringir o crescimento vegetal por deficiÃncia na fotossÃntese. Este efeito deve ser causado indiretamente por mudanÃas nas redes genÃticas e metabÃlicas desencadeadas por alteraÃÃes nos nÃveis de H2O2 (aumentado) e/ou glutationa reduzida (diminuÃda). à provÃvel que o estado redox alterado em mitocÃndrias pelo efeito da GPX possa aumentar a fotossÃntese atravÃs da comunicaÃÃo entre esta organela e cloroplastos por mecanismos ainda nÃo estabelecidos. AlÃm disso, o gene OsGPX1 mostrou ter papel significativo no controle do movimento estomÃtico, que à crucial para a eficiÃncia do uso da Ãgua sob condiÃÃo de estresse salino. As GPX mitocondriais tambÃm parecem estar envolvidas com a dissipaÃÃo do excesso de energia luminosa na forma de calor (NPQ) no aparato do fotossistema II e na rota da fotorrespiraÃÃo. Em conclusÃo, o gene OsGPX1, associado com seu produto proteico e mudanÃas desencadeadas nas redes metabÃlicas e gÃnicas, sÃo essenciais para o crescimento de arroz pelo aumento da fotossÃntese, especialmente a nÃvel de eficiÃncia de uso da luz envolvendo atividade do fotossistema II e eficiÃncia quÃntica do CO2 em condiÃÃes normais de crescimento. Adicionalmente, a GPX1 aparenta mostrar uma importÃncia menor para a resistÃncia ao estresse salino.
The physiological role of glutathione peroxidases (GPX) in plant mitochondria is little known. Their relations with the photosynthesis are unknown, even more in presence of salt stress. This enzyme have great importance in H2O2 and organic hydroperoxides scavenging, contributing in oxidative protection and redox homeostasis. In this study, silenced rice mutants in OsGPX1 and OsGPX3 genes, coding for the mitochondrial proteins, were used to better understand the physiological mechanisms of the role of this protein in growth and photosynthesis. Additionally, these processes were also studied in salt stress conditions with the plants silenced in OsGPX1. The results show, for the first time, that the lacking of a mitochondrial GPX is capable of restricting plant growth by impairment in photosynthesis. This response might be an indirect consequence of changes in gene and metabolic networks trigged by alterations in H2O2 (raised) and/or reduced glutathione (diminished). It is likely that the altered redox state in mitochondria by GPX effects can improve photosynthesis through cross-talk between this organelle and chloroplasts by yet unknown mechanisms. Furthermore, the OsGPX1 gene showed significant role in stomatal control, which is crucial to the water use efficiency under salt stress conditions. The mitochondrial GPX also seems to be involved with dissipation of excess light energy as heat (NPQ) in photosystem II apparatus and in photorespiratory pathway. In conclusion, the OsGPX1 gene, associated with it protein product and changes in gene and metabolic networks, are essential to rice growth by improvement of photosynthesis, especially at light use efficiency level involving photosystem II activity and CO2 quantum efficiency in normal and growth conditions. Additionally, GPX1 seems to be less important to salt stress tolerance.
APA, Harvard, Vancouver, ISO, and other styles
43

Marasinghe, Gishanthi P. K. "OVER-EXPRESSION AND CHARACTERIZATION OF A MITOCHONDRIAL GLYOXALASE II FROM ARABIDOPSIS THALIANA." Miami University / OhioLINK, 2004. http://rave.ohiolink.edu/etdc/view?acc_num=miami1096574528.

Full text
APA, Harvard, Vancouver, ISO, and other styles
44

Kozak, Wojciech. "Ein Beitrag zur Modellierung von Erdreichsonden." Doctoral thesis, 2017. https://tud.qucosa.de/id/qucosa%3A30733.

Full text
Abstract:
Die verlässliche Vorhersage der Wärmeentzugsleistungen als auch der Soletemperaturen in den Sonden sind wichtig für deren Auslegung und Betriebsoptimierung. Es ist ebenso wichtig für die Auslegung und Optimierung der Anlagen im versorgten Gebäude. In der vorliegenden Dissertation wurde versucht, durch eine mathematische Weiterentwicklung von Greenschen Funktionen (g-Funktionen) eine präzisere Lösung für Temperaturverteilung im Erdreich infolge des von einer oder mehreren Sonden verursachten Wärmeentzuges mit verschiedenen Randbedingungen im geologischen Untergrund zu erreichen. Hierzu wurden sechs „neue“ g-Funktionen entwickelt, die vertikal variable Wärmeentzüge einzelner Sonden und Sondenfelder, eine Asymmetrie des Wärmeentzuges der Sonde, den Einfluss einer zusätzlichen Grundwasserströmung und den realen, geschichteten Untergrund berücksichtigen. Die mathematischen Modelle des Erdreichs wurden mit Modellen für die Soleströmung und Wärmeübergabe in der Hinterfüllung der Sonde gekoppelt und anschließend auf ein praktisches Betriebsbeispiel angewendet. Die Arbeit enthält ebenfalls umfangreiche Sichtung existierender Modelle sowie deren Anwendung und vergleichende Bewertung der teilweise komplexen Modellansätze.:Formelzeichen und Abkürzungen 1 Einführung 2 Energiequellen und Aufbau der Erdwärmeübertrager 2.1 Quellen der geothermalen Energie 2.2 Aufbau der Erdwärmeübertrager 2.3 Betriebsverhalten von Erdwärmesonden 2.4 Auslegung der Sonden 3 Vorhandene Modelle 3.1 Soleströmung 3.2 Wärmeübergang in den Rohren der Sonde 3.3 Wärmeleitung in der Hinterfüllung 3.4 Erdreichmodellierung – numerisch 3.5 Erdreichmodellierung mit g-Funktionen 4 Weiterentwicklung der analytischen Modelle 5 Anwendungsbeispiele 185 5.1 Ein praktisches Beispiel 5.2 Auswirkung auf die Jahresarbeitszahl 6 Zusammenfassung Literatur A Ableitung der Bohrlochwiderstände B Ableitung der Funktionen für Randbedingungen C Eidesstattliche Erklärung
The design of the ground heat exchangers (GHE) systems demands the precise prediction of their heat output and the brine temperature. The same information is needed for design and optimization of the HVAC systems coupled to GHEs. In the thesis at hand the Green’s functions (g-Functions) have been used to develop the more accurate solutions for the temperature distribution in soil resulting from the heat extraction from one GHE or a field of GHEs. These solutions consist of six novel g-functions that take account of the vertical variation of the extracted heat flux in one GHE or field of GHEs, of the horizontal ground water flow and of the horizontal variation of the soil properties. The models for prediction of the soil temperature have been coupled with models for brine flow and heat transfer in the GHE’s grout and eventually applied to the simulation of the real world object. Additionally, the thesis contains broad review of the known models and their applications as well as the comparative analysis of the complex modelling assumptions.:Formelzeichen und Abkürzungen 1 Einführung 2 Energiequellen und Aufbau der Erdwärmeübertrager 2.1 Quellen der geothermalen Energie 2.2 Aufbau der Erdwärmeübertrager 2.3 Betriebsverhalten von Erdwärmesonden 2.4 Auslegung der Sonden 3 Vorhandene Modelle 3.1 Soleströmung 3.2 Wärmeübergang in den Rohren der Sonde 3.3 Wärmeleitung in der Hinterfüllung 3.4 Erdreichmodellierung – numerisch 3.5 Erdreichmodellierung mit g-Funktionen 4 Weiterentwicklung der analytischen Modelle 5 Anwendungsbeispiele 185 5.1 Ein praktisches Beispiel 5.2 Auswirkung auf die Jahresarbeitszahl 6 Zusammenfassung Literatur A Ableitung der Bohrlochwiderstände B Ableitung der Funktionen für Randbedingungen C Eidesstattliche Erklärung
APA, Harvard, Vancouver, ISO, and other styles
45

Fang, Guanhua. "Latent Variable Models in Measurement: Theory and Application." Thesis, 2020. https://doi.org/10.7916/d8-gghx-v227.

Full text
Abstract:
Latent variable models play an important role in educational and psychological measurement, where items are presented to individuals, resulting in item response data. Such data entail important information about the individual latent traits, population structure and item design, which are key components to be understood in educational and psychological assessments. This thesis focuses on the development of statistical learning methods based on latent variable models with identifiability theories. The thesis consists of three parts, with three kinds of applications in mind. The first part is on the identifiability of diagnostic classification models (DCMs), which is a special subfamily of latent class models. It aims to examine the test takers' ability based on his/her mastery of set of required skills. A key issue common to DCMs and more generally to latent class model is the identifiability which is a property whether the unknown model or related parameters can be estimated consistently under a suitably defined asymptotic regime. Most existing works focus on the identifiability of DCMs with binary responses and attributes. In this thesis, we provide general identifiability results for DCMs with polytoumous responses and attributes and less parameter restrictions. The second part considers the identifiability of testlet factor models, which is a subfamily of latent variable models with underlying continuous latent traits assumed to follow normal distribution. Similar to DCMs, factor models also suffer from identifiability issues, where the parameters can only be identified up to a rotation in general. However, in most applications, testlet models or bifactor models are popular in educational assessment. They are constrained factor models assuming that the response test items can be accounted for by one primary factor and multiple secondary group-specific factors. By aid of this special structure, we can show that the model can be strictly identifiable and we provide checkable necessary and sufficient conditions accordingly. The third part focuses on the statistical learning in studying the complex problem-solving (CPS) items. With advanced computer technology, there is a new trend of developing CPS test items through online platform, where the examinees are asked to solve challenging tasks in a simulated environment. During the test, all actions performed by examinees will be recored into a log file. Therefore, we can not only observe their final responses, but also have access to their entire solving process. Such data type is known as process data in the measurement literature. The traditional item response model cannot be applicable, at least directly. The analysis of the process data is still in its infancy. In the thesis, we propose a new model-based approach and show its usefulness through an interesting real data application.
APA, Harvard, Vancouver, ISO, and other styles
46

Hofmann, Arnd Joachim [Verfasser]. "Vektorielle Feldmesstechnik bei 150 GHz, 300 GHz und 450 GHz / vorgelegt von Arnd Joachim Hofmann." 2006. http://d-nb.info/978678206/34.

Full text
APA, Harvard, Vancouver, ISO, and other styles
47

Yang, Hung-Yu. "Design and Implementation of 3.1-10.6 GHz UWB, 24-GHz, and 53-GHz CMOS Low Noise Amplifiers." 2008. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0020-1607200815511500.

Full text
APA, Harvard, Vancouver, ISO, and other styles
48

Yang, Hung-Yu, and 楊弘鈺. "Design and Implementation of 3.1-10.6 GHz UWB, 24-GHz, and 53-GHz CMOS Low Noise Amplifiers." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/03275927415611869503.

Full text
Abstract:
碩士
國立暨南國際大學
電機工程學系
96
This thesis aim is to design ultra wideband low noise amplifiers, 24-GHz and 53-GHz CMOS low noise amplifiers. Study the theme can be divided into three parts： In first part, 3.1 ~ 10.6 GHz low noise amplifier is designed for ultra wideband (UWB). The mainly three types of low noise amplifier were using current-sharing technique to achieve low-power consumption. In order to achieve not only high but also flat gain and small group-delay-variation at the same time, the series and shunt inductive peaking were adopted in the output stage to enhance the frequency of the dominant pole and then expand 3-dB bandwidth of the LNA. In the part of input stage, the R-C negative feedback can achieve impedance matching and reduce chip area. First, we design two types of LNA in standard 0.18 um CMOS technology and use the difference gate inductor of series inductive peaking at the same time. The measured results of the first type LNA (lower gate inductor) show the maximum S21 of 13.5 dB, S11 below -12 dB, S22 below -11.8 dB and flat noise figure of 3.61~ 4.68 dB form 3.1 to 10.6 GHz. The measured results of the second type LNA (larger gate inductor) show the flatter S21 of 12.24±0.62 dB. The S11 and S22 below -8.5 dB and flat noise figure of 3.74 ~ 4.74 dB over 3.1-10.6 GHz while consuming 10.33 mW. In order to pursue better performances of the LNA, the third type of LNA is implemented in standard 0.13 um CMOS technology. The measured results show that the 3-dB bandwidth is 13 GHz, the power gain (S21) of 7.92±0.23 dB, input return loss (S11) and output return loss (S22) below -14 dB, and the group-delay-variation only ±16.7 ps over 3.1-10.6 GHz, minimum noise figure of 2.5 dB is achieved at 10.5 GHz while consuming 10.68 mW. The results show that the LNA is suitable for UWB pulse-radio system applications. In the second part, 21~27 GHz low noise amplifier is implemented in standard TSMC 0.18 um CMOS technology and suitable for radar system. To achieve sufficient gain, this LNA is composed of three cascaded common-source stages and a cascode amplifier. The current-sharing technique with inductive peaking is adopted for bandwidth enhancement in the second and third stage. The measured results show that the 3dB bandwidth is 8.5 GHz, the S21 of 9.3±1.3 dB, S11 and S22 below -8.2 dB, noise figure of 4.9~6.1 dB, and the very small group-delay-variation (±8.1 ps) over 21-27 GHz while consuming 27 mW. The last part, low-power-consumption 53-GHz (V-band) low-noise amplifier (LNA) using standard 0.13 um CMOS technology is reported. To achieve sufficient gain, this LNA is composed of four cascaded common-source stages. Current-sharing technique is adopted in the third and the fourth stage to reduce the power dissipation. The output of each stage is loaded with a LC parallel resonance circuit to maximize the gain at the design frequency. This LNA achieved voltage gain (AV) of 14 dB with very low noise figure (NF) of 6.13 dB, and input referred 1-dB compression point (P1dB-in) of –20 dBm at 53 GHz. It consumed very small dc power of 10.56 mW.
APA, Harvard, Vancouver, ISO, and other styles
49

Lu, Hsi-Liang, and 陸熙良. "2.4-GHz Low-Power Receiver and 60-GHz Transmitter CMOS Circuits." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/04940497941411884265.

Full text
Abstract:
碩士
國立交通大學
電信工程系所
97
In this thesis, the radios which are suitable for Wireless Personal Area Network (WPAN) applications are designed and implemented. The thesis consists of two parts. The first part focuses on studying various low-power techniques and realizes two different 2.4-GHz low-power receivers. The second part implements high quality component circuits which are suitable for 60-GHz band applications. First, we study different low-power techniques. Because the passive mixer is a common component of a direct-conversion receiver, we also investigate the flicker noise of passive mixers. Then, we implement a 2.4-GHz low-power receiver with passive mixers, and a 2.4-GHz low-power receiver with subthreshold biasing technique. Both chips are implemented in TSMC 0.18-um CMOS technology. Second, we implement different types of 60-GHz sub-harmonic upconverters in TSMC 0.13-um CMOS technology, and propose transformer-type balun to combine RF signal. In order to provide good LO source, we design a QVCO using three-line coupler. This QVCO operates at 0.6V, and consumes 7.6mW. And the FoM is -203.6dBc/Hz.
APA, Harvard, Vancouver, ISO, and other styles
50

Wang, Bing-Han, and 王秉翰. "Novel 2.4 GHz/5.2 GHz Dual-Band Fractional-N Frequenncy Synthesizers." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/87214540263095974081.

Full text
Abstract:
碩士
國立中正大學
電機工程研究所
93
The thesis accomplishes three fractional-N frequenncy synthesizers. Firstly, a new architecture with proposed prescalar and sigma-delta modular controller is presented. The design example of fractional-N frequency synthesizer is accomplished and applied to the Bluetooth system. In addition, a new dual-band franctional-N Frequency Synthesizer architecture is also proposed. This architecture adopts dual-band voltage-controlled oscillator (VCO) with small area due to less inductor rquirement. The whole chip is fabricated and can be applied to Bluetooth system and 802.11a system, respectively. Lastly, Because the low jitter and fast-locking are very important in frequency synthesizer. Therefore, a new phase-and-frequency detecter (PFD), which can adjust the charge-pump current properly, is proposed and applied on the 2.4 GHz franctional-N frequency synthesizer design. The three frequency synthesizers are implemented in TSMC 0.18um 1P6M CMOS process. The measured parts of results show that the tuning range of VCO is 2.298 GHz~2.915 GHz, and phase noise is -98.60 dBc/Hz @100 KHz at power consumption of 19.8 mW. The maximum operation frequency of multi-mode prescaler is 1.6 GHz, at the power consumption of 10.7334 mW.
APA, Harvard, Vancouver, ISO, and other styles
You might also be interested in the bibliographies on the topic 'OR GHX' for other source types:
Journal articles Books
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!

To the bibliography