Dissertations / Theses on the topic 'Two-components'
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Benz, Johan Philipp. "Characterization of two components of the chloroplastic Tic complex." Diss., lmu, 2009. http://nbn-resolving.de/urn:nbn:de:bvb:19-112160.
Full textYehia, Khaled Ahmed. "Reference stresses for impression creep and two material components." Thesis, University of Nottingham, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.260672.
Full textSchuck, Natalie. "Functional analysis of two components of the chloroplastic TIC complex." Diss., Ludwig-Maximilians-Universität München, 2013. http://nbn-resolving.de/urn:nbn:de:bvb:19-164589.
Full textPark, Sang Hyan. "The effects between two slotted plate flow meter under single, two, three components flow condition." Texas A&M University, 2004. http://hdl.handle.net/1969.1/1522.
Full textBiverot, Hans. "Multi-user retinal displays with two components. New degrees of freedom." Doctoral thesis, KTH, Physics, 2001. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3281.
Full textStockton, Charles M. Turk Randall. "Successful professional development model components in two high achieving Missouri school districts." Diss., A link to full text of this thesis in SOAR, 2007. http://soar.wichita.edu/dspace/handle/10057/1111.
Full text"May 2007." Title from PDF title page (viewed on December 14, 2007). Thesis adviser: Randall Turk. Includes bibliographic references (leaves 210-228).
au, Upstream@iinet net, and Kaye Natalie Mills. "The Effects of two Components of the Aussie Optimism Program on Social Skills." Murdoch University, 2007. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20071107.143156.
Full textLi, Yazhou. "Regulation of the expression of the two components of liver glucose-6-phosphatase." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0019/NQ55469.pdf.
Full textMills, Kaye N. "The effects of two components of the Aussie Optimism Program on social skills /." Access via Murdoch University Digital Theses Project, 2007. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20071107.143156.
Full textMills, Kaye Natalie. "The effects of two components of the aussie optimism program on social skills." Thesis, Mills, Kaye Natalie (2007) The effects of two components of the aussie optimism program on social skills. Professional Doctorate thesis, Murdoch University, 2007. https://researchrepository.murdoch.edu.au/id/eprint/747/.
Full textYang, Shuai. "Development of Non-linear Two-Terminal Mass Components for Application to Vehicle Suspension Systems." Thesis, Université d'Ottawa / University of Ottawa, 2017. http://hdl.handle.net/10393/36497.
Full textNagpure, Bhupendra Singh. "The Effects of Reasoning about Vector Components on Student Understanding of Two-Dimensional Acceleration." Fogler Library, University of Maine, 2008. http://www.library.umaine.edu/theses/pdf/NagpureBS2008.pdf.
Full textChen, Yifan Verfasser], and Fabrizio [Akademischer Betreuer] [Catanese. "Two Irreducible Components of the Moduli Space M can 1,3 / Yifan Chen. Betreuer: Fabrizio Catanese." Bayreuth : Universitätsbibliothek Bayreuth, 2012. http://d-nb.info/1020871121/34.
Full textTwolan-Strutt, Lisa. "Competition intensity and its above- and below-ground components in two contrasting wetland plant communities." Thesis, University of Ottawa (Canada), 1994. http://hdl.handle.net/10393/9921.
Full textEnglish, Jonathan. "Machine vision for the determination of identity, orientation and position of two dimensional industrial components." Thesis, De Montfort University, 1996. http://hdl.handle.net/2086/4811.
Full textLewis, Ceri Nicola. "Fitness components of seasonal reproduction in two polychaeta: Nereis virens (Sars) and Arenicola marina (L.)." Thesis, University of Newcastle Upon Tyne, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.251953.
Full textYeboah, Kwasi. "Identification of Transcription Regulators of the AlgZ/R Two-Components Regulatory System in Pseudomonas aeruginosa." Digital Commons @ East Tennessee State University, 2021. https://dc.etsu.edu/etd/3854.
Full textSchuck, Natalie [Verfasser], and Jürgen [Akademischer Betreuer] Soll. "Functional analysis of two components of the chloroplastic TIC complex / Natalie Schuck. Betreuer: Jürgen Soll." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2013. http://d-nb.info/104601160X/34.
Full textTibbo, Jamie J. "Physical interactions between MexA and MexB, two components of a multidrug efflux pump in Pseudomonas aeruginosa." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0021/MQ52955.pdf.
Full textOcchino, Deborah Ann. "Vibrio cholerae iron transport : characterization of two tonB systems and components of a heme transport system /." Digital version accessible at:, 1998. http://wwwlib.umi.com/cr/utexas/main.
Full textLawton, Daniel Graham. "Analysis of the type III secretion system of Yersinia pestis through characterisation of two key virulence components." Thesis, Imperial College London, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.401727.
Full textFlanigan, Sean Gerard. "From Deux Danses to Fluctuations: Compositional components and innovations in two solo trombone works of Jean-Michel Defaye." Thesis, connect to online resource, 2006. http://www.unt.edu/etd/all/Aug2006/flanigan%5Fsean%5Fgerard/index.htm.
Full textSystem requirements: Adobe Acrobat Reader. Accompanied by 4 recitals, recorded June 28, 1999, Jan. 24, 2000, Jan. 29, 2001, and Apr. 10, 2006. Includes bibliographical references and discography (p. 66-70).
Mothapo, Matholo Joyce. "Physico-chemical properties and selected nutritional components of Wild Medlar (Vangueria Infausta) fruit harvested at two haevesting time." Thesis, University of Limpopo, 2014. http://hdl.handle.net/10386/1391.
Full textWild medlar (Vangueria infausta subsp. infausta) is a popular indigenous fruit available and consumed by rural communities in Limpopo Province, South Africa. Inadequate post-harvest practices in indigenous fruit plants including V. infausta fruit forms major constrains in expanding their production. There is scanty information documented on neither objective nor subjective harvesting indices of indigenous fruit plants consumed by locals in sub-Saharan Africa. Thus, the objective of this study was to determine the effect of harvesting time on physico-chemical properties and selected nutritional composition of V. infausta fruit. Fruits were harvested twice, where two harvesting times were regarded as treatments and each tree as replication. The reduction for fruit weight, sugar content and sugar/acid ratio was highly significant (P ≤ 0.05), whereas for average fruit diameter, seed weight, acid ratio and pH content this may imply that the listed parameters are treatment which was non-significant (P ≤ 0.05). The treatment reduced P, K, Mn and Fe by 33%, 18%, 3% and 7%, respectively. On the other hand, treatments had no effect on N and Ca. The reduction of phosphorus was highly significant (P ≤ 0.05), whereas for N, K, Ca, Mn and Fe treatment impact was non-significant (P ≤ 0.05). Similarly, the treatment consistently reduced moisture content and increased dry matter and crude protein of V. infausta by 76%, 300% and 7%, respectively. The reduction of moisture content, increase in dry matter was highly significant (P ≤ 0.05), whereas crude protein treatment impact was non-significant (P ≤ 0.05). The data indicated that the best time to harvest V. infausta fruit was during January when fruits were cosmetically appealing and not wrinkled. This study demonstrated that there was less variation in some measured objective harvesting indices of V. infausta fruit harvested at two harvesting time. More work would be required to do physico-chemical properties and selected mineral elements analysis from wide growth habitat for conclusive recommendations.
Stuart, Alastair David. "The effects of a highly viscous liquid phase on two-phase flow in a vertical pipe and pipeline components." Thesis, Heriot-Watt University, 2005. http://hdl.handle.net/10399/233.
Full textMason, James Bryan. "Analysis of site structure and post-depositional disturbance at two Early Holocene components, Richard Beene site (41BX831), Bexar County, Texas." Thesis, Texas A&M University, 2003. http://hdl.handle.net/1969/584.
Full textMårtensson, Emil. "The democratic separation of two political orders : A statistical study on the effects of substantive and procedural components on democracy." Thesis, Linnéuniversitetet, Institutionen för statsvetenskap (ST), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-90934.
Full textFarooq, Salma. "The determination of dyers' perceived components of colour difference (depth, brightness and hue) between two similar colours from their spectral reflectance values." Thesis, Heriot-Watt University, 2011. http://hdl.handle.net/10399/2443.
Full textChevalier, Franck. "Influence of medium components on complex carbohydrates structures : the examples of two relevant carbohydrate moieties found on glycoproteins heparin and GPI-anchor." Université Joseph Fourier (Grenoble), 2004. http://www.theses.fr/2004GRE10120.
Full textGlycoproteins and proteoglycans are involved in various phenomena which could be regulated by the carbohydrates chains linked after translation to the core protein. Structure and dynamics of these modifications depend on the interactions with take place with others molecules present in the same milieu. Their effect on the structure is sometimes neglected and molecules are often studied as isolated and pure. The influence of these interactions has been put under focus through two different examples : heparin and GPI anchor. The influence of the sulphation pattern of heparin on their interaction with counter ions and the anchorage of a GPI into a micelle have been studied by NMR spectroscopy and Modelling
Kamprad, Antje [Verfasser], and Michael [Akademischer Betreuer] Kolbe. "Expression, purification and structural analysis of key components of the Shigella T3SS basal body in two states / Antje Kamprad ; Betreuer: Michael Kolbe." Hamburg : Staats- und Universitätsbibliothek Hamburg, 2020. http://d-nb.info/1210646986/34.
Full textTieu, Quinton Quynh. "Mdv1p and Fis1p, two novel components of the mitochondrial fission complex, are required to regulate the Dnm1p-dependent mitochondrial fission in Saccharomyces cerevisiae /." For electronic version search Digital dissertations database. Restricted to UC campuses. Access is free to UC campus dissertations, 2003. http://uclibs.org/PID/11984.
Full textKeßel, Yvonne Nicole [Verfasser], Frank [Gutachter] Goldhammer, and Andreas [Gutachter] Klein. "Development of interactive performance measures for two components of ICT Literacy: successfully accessing and evaluating information / Yvonne Nicole Keßel ; Gutachter: Frank Goldhammer, Andreas Klein." Frankfurt am Main : Universitätsbibliothek Johann Christian Senckenberg, 2018. http://d-nb.info/1154852903/34.
Full textDu, Plessis A. J. E. "The response of the two interrelated river components, geomorphology and riparian vegetation, to interbasin water transfers in the Orange-Fish-Sundays River Interbasin Transfer Scheme." Thesis, Rhodes University, 2000. http://hdl.handle.net/10962/d1005526.
Full textKaufman, Jason R. "Digital video watermarking using singular value decomposition and two-dimensional principal component analysis." Ohio : Ohio University, 2006. http://www.ohiolink.edu/etd/view.cgi?ohiou1141855950.
Full textCoumes, Stéphanie. "Les modules de "détection / résistance " aux antibiotiques peptidiques chez les firmicutes." Thesis, Aix-Marseille 2, 2011. http://www.theses.fr/2011AIX22062/document.
Full textSignal transduction systems and ABC transporters often contribute jointly to adaptive bacterial responses to environmental changes. In Bacillus subtilis, three such pairs, thereafter called modules, are involved in responses to antibiotics: BceRSAB, PsdRSAB and YxdJKLM. They are characterized by a histidine kinase belonging to the Intramembrane Sensing – Histine Kinase family (IM-HK) and by a Membrane Spanning Domain (MSD) possessing an unusually large extracytoplasmic loop. Using a phylogenomic approach we were able to demonstrate that such modules, associating a phosphorelay and an ABC transporter, are specific but widespread in Firmicutes where they originated. This analyse highlight a highly dynamic evolutionary history involving numerous horizontal gene transfers, duplications and lost events, leading to a great variety of Bce-like module repertories in members of this bacterial phylum. Based on fine phylogenetic analyses, the Bce-like modules were divided into six well-defined subfamilies. Functional studies were performed on some members of subfamily IV comprising the bacitracin resistance module BceRSAB of B. subtilis, the expression of which being found to require, in the presence of bacitracin, the signal transduction system as well as the ABC transporter itself. The present results indicate that two other members of subfamily IV, YtsCD of B. licheniformis and BceAB of B. halodurans, were also found to participate in bacitracin resistance processes. The results also suggest that in these modules the ABC transporter works as the first sensor of the antibiotic and that it then activates the signal transduction system through an interaction between one of the two ABC transporter domains and the module kinase.Bacitracin dependent expression of bceAB and bacitracin resistance processes were shown to require the presence of the BceB translocator loop suggesting a crucial role for this loop as well at a functional level, as at a structural level.This study suggests that the original BceRSAB module regulatory mechanism might be generalised to other modules and would constitute an important common antibiotic resistance mechanism in Firmicutes which comprise many human pathogens
Riofrío, almeida María Cristina. "Etude des écoulements diphasiques pour le refroidissement des composants électroniques en systèmes embarqués." Thesis, Université Grenoble Alpes (ComUE), 2019. http://www.theses.fr/2019GREAI022/document.
Full textThis dissertation concerns the study of two-phase flow cooling of electronic components in embedded systems. From a literature review, Spray Cooling was selected as a promising technique for dissipating heat fluxes above 100 W/cm2. A hydraulic study, using water and HFE7100 as coolants, has validate models for determining the size and speed of drops from a selection of spray nozzles. Regarding the thermal study, we have designed a test section (evaporator) to study cooling in a two-phase closed loop system.Given the complexity of Spray Cooling systems, which are influenced by several parameters and involve several physical phenomena, the nucleate boiling phenomenon has been isolated in a Pool Boling system with an identical heating element as Spray Cooling experiment. To improve heat exchange, 6 surfaces with different structures (macroscopic, microscopic and hybrid) were selected. The boiling test results with these surfaces have been compared with a smooth surface for both Spray Cooling and Pool Boiling.On one hand, in Spray Cooling tests, the macrostructured surfaces dissipated heat flux up to 140 W/cm2 with significant heat transfer coefficients. On the other hand, in the Pool Boling system, one of the hybrid surfaces has shown to be the most efficient.The results reported in this dissertation contributes on the understanding of the boiling mechanisms of heat transfer in Spray Cooling. Likewise, they open the way to the study of improvements and optimizations of the system for its use in embedded systems
Du, Sautoy Neil. "The characterization of the components of the energy and water balance within hedgerow orchards for the verification of a two-dimensional water balance and energy interception model for fruit trees." Thesis, University of Pretoria, 2005. http://hdl.handle.net/2263/28864.
Full textThesis (PhD (Agriculturae: Plant Production))--University of Pretoria, 2007.
Plant Production and Soil Science
unrestricted
Marszalek, Marta Anna. "The DosRST two-component system of Mycobacterium tuberculosis: Characterizing the activation mechanism of DosR response regulator as a potential target for novel antimycobacterial drugs." Doctoral thesis, Universitat Ramon Llull, 2014. http://hdl.handle.net/10803/275939.
Full textLa tuberculosis, la enfermedad infecciosa causada por Mycobacterium tuberculosis, es un problema de salud global que provoca aproximadamente 2 millones de muertes anuales. Un tercio de la población mundial se encuentra crónicamente infectada con Mycobacterium tuberculosis pero no muestra síntomas clínicos aunque tiene un riesgo de un 10% de desarrollar la enfermedad, lo que representa un reservorio incontrolable de tuberculosis. En esta condición asintomática, conocida como tuberculosis latente, Mycobacterium tuberculosis se localiza en lesiones granulomatosas en el huésped y es resistente a los medicamentos antimicobacterianos existentes en la actualidad. En bacterias, los sistemas regulatorios de dos componentes son un conjunto de proteínas implicadas en la adaptación a cambios en el entorno del microorganismo. Un sistema de dos componentes típico consta de una histidina quinasa unida a membrana que tiene un papel esencial como sensor de los cambios ambientales y un regulador transcripcional citosólico que ejerce su función controlando la expresión de genes diana. Este par de proteínas funciona como un interruptor molecular que controla distintas respuestas adaptativas a cambios en el ambiente celular. Mycobacterium tuberculosis tiene 11 sistemas de dos componentes completos. El sistema DosRST, compuesto por un regulador transcripcional, DosR, y dos histidinas quinasas, DosS y DosT, juega un papel estelar en la adaptación de Mycobacterium tuberculosis a la tuberculosis latente. DosS y DosT se autofosforilan en residuos conservados de histidina y ambas proteínas transfieren esta unidad de fosfato al residuo de ácido aspártico en posición 54 del regulador DosR. La fosforilación de Asp54 es un interruptor que activa a DosR e incrementa su afinidad por los promotores de los genes que regula. Las treoninas 198 y 205 de DosR juegan un papel crucial en la dimerización de DosR y en su unión al DNA. Las dinámicas moleculares realizadas con la proteína salvaje DosR y con versiones mutantes muestran diferencias notables en la formación del dímero activo. También muestran una reducción o abolición completa de las interacciones proteína-DNA a causa de las repulsiones generadas por los residuos mutantes cargados negativamente. Más aún, las sustituciones en Thr198 y Thr205 tienen un importante efecto en la fosforilación química y enzimática de DosR así como también en su defosforilaición catalizada por DosS. El sistema de dos componentes DosRST es una buena diana para el desarrollo de nuevos compuestos con actividad antimicobacteriana contra formas durmientes de Mycobacterium tuberculosis. Se ha iniciado un programa de investigación dirigido al desarrollo de inhibidores específicos de la proteína reguladora DosR, usando como punto de partida compuestos comerciales estructuralmente relacionados con un derivado fenilcumarínico que ha sido descrito como molécula que interfiere en la interacción DosR-DNA.
Tuberculosis, the infectious disease caused by Mycobacterium tuberculosis, is a global health problem with approximately two million deaths annually. One-third of the world population is chronically infected with Mycobacterium tuberculosis but do not show clinical symptoms although there is a 10% risk to development active disease, representing an uncontrollable reservoir of tuberculosis. In this asymptomatic condition, referred to as latent tuberculosis, Mycobacterium tuberculosis is located within granulomatous lesions in the host and is resistant to currently available antimycobacterial drugs. Two-component regulatory systems in bacteria are a major class of signal transduction proteins involved in adaptation to environmental changes. Typical system contains a membrane-bound histidine kinase that plays a crucial role in sensing environmental stimuli, and a cytosolic response regulator. This pair of proteins functions as a molecular switch that controls diverse adaptive environmental responses. Mycobacterium tuberculosis has eleven complete two-component systems. The DosRST system, composed of a response regulator, DosR, and two histidine kinases, DosS and DosT, plays a key role in Mycobacterium tuberculosis adaptation to latent tuberculosis. DosS and DosT autophosphorylate at conserved histidine residues and both proteins transfer this phosphor moiety to aspartic acid residue 54 of DosR. The phosphorylation of Asp54 serves as a switch to activate DosR and to increase the affinity for its cognate DNA promoters. Threonines 198 and 205 of DosR play a crucial role in DosR dimerization and DNA binding. The molecular dynamics with wild type and mutant version of DosR show different stability in the formation of the active DosR dimer. They also show the reduction or the abolishment of protein-DNA interactions because of the repulsions generated by negatively charged mutated residues. Moreover, substitutions in threonines 198 and 205 of DosR have a relevant effect on the chemical and enzymatic phosphorylation of DosR and on its DosS-catalysed dephosphorylation. The DosRST two-component system is a good target for the development of novel antimycobacterial drugs against dormant forms of M. tuberculosis. A structure-based discovery programme of inhibitors of DosR response regulator has been initiated with commercially available compounds showing a certain degree of similarity with a phenylcoumarin derivative previously described as DosR-DNA interfering molecule.
Dirschnabel, Daniela Elisabeth [Verfasser], Ulrich [Gutachter] Kück, and Franz [Gutachter] Narberhaus. "NAD(P)H oxidases are components of two distinct pathways regulating sexual development in the fungus Sordaria macrospora / Daniela Elisabeth Dirschnabel ; Gutachter: Ulrich Kück, Franz Narberhaus ; Fakultät für Biologie und Biotechnologie." Bochum : Ruhr-Universität Bochum, 2014. http://d-nb.info/1189419556/34.
Full textDu, Plessis Lindie. "An investigation of the integrity of two components of the cerebellar neurocircuitry involved in classical eyeblink conditioning in children prenatally exposed to alcohol: a magnetic resonance spectroscopy and functional magnetic resonance imaging study." Doctoral thesis, University of Cape Town, 2014. http://hdl.handle.net/11427/13341.
Full textImpairment in classical eyeblink conditioning (EBC) has previously been reported in children with fetal alcohol spectrum disorders (FASD) (Jacobson et al., 2008). The deep cerebellar nuclei and cerebellar cortex are critical elements of the cerebellar-brainstem circuitry that mediates EBC (Green et al., 2002a; Yeo and Hardiman, 1992; Perret et al., 1993). In this study, we used magnetic resonance spectroscopy (MRS) and functional MRI (fMRI) to assess the effects of prenatal alcohol exposure on brain metabolism in the cerebellar deep nuclei and brain function in the cerebellar cortex, respectively. We found that higher levels of prenatal alcohol exposure were associated with lower levels of both N-Acetylaspartate (NAA) and choline-containing metabolites, and with higher levels of glutamate plus glutamine (Glx), suggesting a disruption of the glutamate-glutamine cycling involved in glutamatergic excitatory neurotransmission. Since the interpositus nucleus is one of the most crucial structures in the acquisition of the EBC response, abnormal metabolism in this region could be responsible for altered synaptic plasticity in children with FASD. Of the four cerebellar regions that were identified as being activated more by control children during rhythmic vs. non-rhythmic finger tapping, smaller differences in BOLD (blood oxygenation level dependent) activation were observed in children with FASD in two, namely vermis IV-V and right Crus I. Increasing levels of prenatal alcohol exposure were, however, associated with smaller differences in activation in all four regions, all of which have previously been linked to timed responses. In the paced/unpaced finger tapping fMRI study, we found four regions where increased BOLD activation during unpaced tapping compared to rest was associated with improved ability to maintain rhythm as evidenced by lower intertapping variability - right VIIIa and b, left VIIIa and right VI. These regions have previously been implicated in motor control with additional evidence of timing in lobule VI. In three of the regions, all except right VIIIa, increasing alcohol exposure was related to smaller increases in activation during unpaced tapping, with the strongest relations seen in the dosage dependent variable. Interestingly, the location of the activation in right VI is similar to a region that has been implicated in studies of EBC (Blaxton et al., 1996; Cheng et al., 2008). Our results point to altered metabolic levels in the deep nuclei and reduced functioning of several cerebellar cortical regions in children with FASD, highlighting the extensive damage caused by prenatal alcohol exposure. Although we did not find associations of EBC performance with either metabolite levels or activity in these regions, suggesting that damage to these areas are not primarily responsible for the observed EBC deficit, the extent of this damage could play a role in the impaired EBC performance seen in these children.
Barbosa, Paula Cristina Souza. "Padronização de óleos de Copaifera multijuga hayne por meio de técnicas cromatográficas." Universidade Federal do Amazonas, 2012. http://tede.ufam.edu.br/handle/tede/3340.
Full textCoordenação de Aperfeiçoamento de Pessoal de Nível Superior
As árvores do gênero Copaifera (Leguminosae), conhecidas popularmente como copaibeiras, exsudam um óleo-resina extensamente utilizado na medicina popular e por indústrias farmacêuticas e de cosméticos, devido às suas atividades cicatrizante e anti-inflamatória. Quimicamente, esses óleos se caracterizam pela presença de hidrocarbonetos sesquiterpênicos, sesquiterpenos oxigenados e ácidos diterpênicos. No entanto, a composição química desses óleos-resina é variável e ainda não se tem conhecimento dos fatores que as determinam, embora vários fatores bióticos e abióticos sejam considerados fontes dessa variação. Essa variação dificulta a padronização da composição química desses óleos, comprometendo seu controle de qualidade e consequentemente a qualidade dos produtos a que darão origem, fato que tem causado um grande entrave à sua maior aplicação e comercialização. Essa variabilidade em sua composição química já é bastante conhecida e relatada na literatura, mas a maioria dos estudos realizados têm se restringido a caracterizar quimicamente o óleo-resina e poucos tem se preocupado em estudar as causas dessas variações. O objetivo deste trabalho foi padronizar a composição química dos óleos de copaíba por meio de técnicas de cromatografia em fase gasosa acoplada à detectores de ionização de chama (CG-DIC) e espectrometria de massas (CG-EM) e cromatografia em fase gasosa bidimensional abrangente (CGXCG); analisar estatisticamente a influência de fatores abióticos como sazonalidade, tipo de solo e diâmetro à altura do peito (DAP), além da infestação por cupins, sobre a composição química desses óleos. Além disso, foram comparados 5 métodos de esterificação dos ácidos diterpênicos presentes nos óleos de copaíba envolvendo catálise ácida, que utilizam BF3/MeOH, H2SO4/MeOH e HCl/MeOH, levando-se em consideração suas eficiências e frequências analíticas, além do consumo e toxicidade dos reagentes utilizados, relação custo benefício e, principalmente, a possibilidade de alteração/degradação da estrutura dos constituintes quando aplicados em óleos de copaíba. Para isso foram obtidos óleos de copaíba de 3 coletas: em novembro de 2004 e novembro de 2005 (épocas consideradas secas) e em maio de 2005 (época considerada chuvosa). No total, 43 amostras de óleo-resina de copaíba foram coletadas na Reserva Ducke (Manaus-AM), de 33 espécimes diferentes, que possuíam diferentes DAP s e se encontravam em diferentes tipos de solo. As análises por CG-DIC e CG-EM permitiram a identificação de 35 constituintes: sendo 22 hidrocarbonetos sesquiterpênicos, 9 sesquiterpenos oxigenados e 4 ácidos diterpênicos. Enquanto a análise por CGxCG permitiu a identificação de outros 13 sesquiterpenos, além de 7 monoterpenos, inéditos em óleos-resina de copaíba. O β-cariofileno e seu óxido foram os constituintes majoritários em 29 e 11 amostras, respectivamente. As análises hierárquica por agrupamento (HCA) e de componentes principais (PCA) evidenciaram a existência de dois grupos distintos com diferentes perfis cromatográficos, em que foi comprovada apenas a influência do tipo de solo, sobre a composição química desses óleos. Outros fatores analisados como sazonalidade, DAP e infestação por cupins, não tiveram influência sobre a composição química dos óleos-resina de copaíba. Quanto aos métodos de esterificação, as análises das 5 metodologias testadas, apesar de terem sido reprodutíveis, não se mostraram eficientes, ao passo que não permitiram a identificação dos constituintes formados e levaram à formação de artefatos.
French, William. "Two-dimensional simulation of thin film silicon-on-insulator MOSFETs." Thesis, Queen's University Belfast, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.333811.
Full textBeer, Katharina [Verfasser], and Charlotte [Gutachter] Helfrich-Förster. "A Comparison of the circadian clock of highly social bees (\(Apis\) \(mellifera\)) and solitary bees (\(Osmia\) \(spec.\)): Circadian clock development, behavioral rhythms and neuroanatomical characterization of two central clock components (PER and PDF) / Katharina Beer ; Gutachter: Charlotte Helfrich-Förster." Würzburg : Universität Würzburg, 2021. http://d-nb.info/1228272204/34.
Full textMatthews, Paul. "The fabrication and measurement of a two-dimensional electron gas base hot electron transistor." Thesis, University of Cambridge, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.284193.
Full textMyers, Paul G. "A two-dimensional spoiler of arbitrary chordwise position in a low speed flow." Thesis, University of Bristol, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.303755.
Full textBerenguer, Verdú Antonio José. "Analysis and design of efficient passive components for the millimeter-wave and THz bands." Doctoral thesis, Universitat Politècnica de València, 2017. http://hdl.handle.net/10251/84004.
Full textEsta tesis aborda problemas actuales en el análisis y diseño de componentes pasivos en las bandas de onda milimétrica y Terahercios (THz). Se presentan nuevas técnicas de análisis y modelado de estructuras complejas, procedimientos de diseño, e implementación práctica de dispositivos pasivos avanzados. La primera parte de la tesis se dedica a componentes pasivos de THz. Actualmente no se disponen de guías de onda adecuadas a THz debido a que ambos, metales y dieléctricos, introducen grandes pérdidas. En consecuencia, no es adecuado escalar las estructuras metálicas cerradas usadas en microondas, ni las guías dieléctricas usadas a frecuencias ópticas. Entre un gran número de recientes propuestas, la Single Wire Waveguide (SWW) destaca por su baja atenuación y casi nula dispersión. No obstante, como guía superficial, la SWW presenta difícil excitación y radiación en curvas. El uso de un recubrimiento dieléctrico, creando la Dielecric-Coated Single Wire Waveguide (DCSWW), alivia estos inconvenientes, pero las ventajas anteriores se pierden y nuevos problemas aparecen. Hasta la fecha, no se han encontrado soluciones adecuadas para la radiación en curvas de la SWW. Además, se echa en falta una caracterización rigurosa de ambas guías. Esta tesis presenta, por primera vez, un análisis modal completo de SWW y DCSWW, adecuado a la banda de THz. Este análisis es aplicado posteriormente para evitar el problema de la radiación en curvas. Se presentan y validan experimentalmente diversas estructuras y procedimientos de diseño. La segunda parte de la tesis abarca componentes pasivos de ondas milimétricas. Actualmente, estos componentes sufren una importante degradación de su respuesta debido a que resulta difícil asegurar contacto metálico y alineamiento adecuados para la operación a longitudes de onda tan pequeñas. Además, la absorción dieléctrica incrementa notablemente a estas frecuencias. En consecuencia, tanto guías metálicas huecas como líneas de transmisión planares convencionales presentan gran atenuación, siendo necesario considerar topologías alternativas. Las Gap Waveguides (GWs), basadas en una estructura periódica que introduce un efecto de Electromagnetic Bandgap, resultan muy adecuadas puesto que no requieren contacto entre partes metálicas y evitan las pérdidas en dieléctricos. No obstante, a pesar del potencial de las GWs, varias barreras impiden la consolidación y uso universal de esta tecnología. Por una parte, la compleja topología de las GWs dificulta el proceso de diseño dado que las simulaciones de onda completa consumen mucho tiempo y no existen actualmente métodos de análisis y diseño apropiados. Por otra parte, es necesario evidenciar el beneficio de usar GWs mediante dispositivos GW de altas prestaciones y comparativas adecuadas con estructuras convencionales. Esta tesis presenta diversos métodos de análisis eficientes, modelos, y técnicas de diseño que permitirán la síntesis de dispositivos GW sin necesidad de un conocimiento profundo de esta tecnología. Asimismo, se presentan varios filtros de banda estrecha operando en las bandas Ka y V con altas prestaciones, así como una comparativa rigurosa con la guía rectangular.
Aquesta tesi aborda problemes actuals en relació a l'anàlisi i disseny de components passius en les bandes d'ona mil·limètrica i Terahercis. Es presenten noves tècniques d'anàlisi i modelatge d'estructures complexes, procediments de disseny, i implementació pràctica de dispositius passius avançats. La primera part de la tesi es focalitza en components passius de THz. Actualment no es disposen de guies d'ona adequades a THz causa que tots dos, metalls i dielèctrics, introdueixen grans pèrdues. En conseqüència, no és adequat escalar les estructures metál·liques tancades usades en microones, ni les guies dielèctriques usades a freqüències òptiques. Entre un gran nombre de propostes recents, la Single Wire Waveguide (SWW) destaca per la seua baixa atenuació i quasi nul·la dispersió. No obstant això, com a guia superficial, la SWW presenta difícil excitació i radiació en corbes. L'ús d'un recobriment dielèctric, creant la Dielecric-Coated Single Wire Waveguide (DCSWW), alleuja aquests inconvenients, però els avantatges anteriors es perden i nous problemes apareixen. Fins a la data, no s'han trobat solucions adequades per a la radiació en corbes de la SWW. A més, es troba a faltar una caracterització rigorosa d'ambdues guies. Aquesta tesi presenta, per primera vegada, un anàlisi modal complet de SWW i DCSWW, adequat a la banda de THz. Aquest anàlisi és aplicat posteriorment per evitar el problema de la radiació en corbes. Es presenten i validen experimentalment diverses estructures i procediments de disseny. La segona part de la tesi es centra en components passius d'ones mil·limètriques. Actualment, aquests components pateixen una important degradació de la seua resposta a causa de que resulta difícil assegurar contacte metàl·lic i alineament adequats per a l'operació a longituds d'ona tan menudes. A més, l'absorció dielèctrica incrementa notablement a aquestes freqüències. En conseqüència, tant guies metàl·liques buides com línies de transmissió planars convencionals presenten gran atenuació, sent necessari considerar topologies alternatives. Les Gap Waveguides (GWs), basades en una estructura periòdica que introdueix un efecte de Electromagnetic Bandgap, resulten molt adequades ja que no requereixen contacte entre parts metàl·liques i eviten les pèrdues en dielèctrics. No obstant, tot i el potencial de les GWs, diverses barreres impedixen la consolidació i ús universal d'aquesta tecnologia. D'una banda, la complexa topologia de les GWs dificulta el procés de disseny atés que les simulacions d'ona completa consumeixen molt de temps i no existeixen actualment mètodes d'anàlisi i disseny apropiats. D'altra banda, és necessari evidenciar el benefici d'utilitzar GWs mitjançant dispositius GW d'altes prestacions i comparatives adequades amb estructures convencionals. Aquesta tesi presenta diversos mètodes d'anàlisi eficients, models, i tècniques de disseny que permetran la síntesi de dispositius GW sense necessitat d'un coneixement profund d'aquesta tecnologia. Així mateix, es presenten diversos filtres de banda estreta operant en les bandes Ka i V amb altes prestacions, així com una comparativa rigorosa amb la guia rectangular.
Berenguer Verdú, AJ. (2017). Analysis and design of efficient passive components for the millimeter-wave and THz bands [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/84004
TESIS
Holt, Kathleen. "CONSTRUCTS UNIQUE TO TWO VOLUSIA COUNTY ELEMENTARY WRITING PROGRAMS." Doctoral diss., University of Central Florida, 2006. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/2744.
Full textEd.D.
Department of Teaching and Learning Principles
Education
Curriculum and Instruction
Mackichan, Calum. "Organization of secretion components in bacillus subtilis." Thesis, Paris 11, 2013. http://www.theses.fr/2013PA112122.
Full textIn the years since the cloning of GFP, the field of bacterial cell biology has characterized a variety of specific protein localization patterns in the bacterial membrane. The vast majority of early subcellular localization studies made use of inducible GFP fusions, which generally required the presence of high concentrations of inducer, and can therefore be considered to be overexpressed. An outstanding question remains over the organization of natively expressed proteins in the membrane. Here, we have investigated the localization of functional GFP fusions to proteins catalyzing important membrane processes; the secretion motor protein SecA, the membrane insertase YidC1, and the essential phospholipid synthase PgsA using total internal reflection fluorescence microscopy (TIRFM). This allowed natively expressed proteins to be localized with temporal resolution that can capture their dynamics. We characterized dynamic complexes dispersed throughout the membrane displaying diffusive movement with no preferred trajectories. Further characterization focused upon identifying conditions in which the localization pattern was disturbed. A polar mislocalization was identified in a cardiolipin mutant strain. The yeast two-hybrid (Y2H) approach is a robust approach to detect binary interactions on a proteome-scale. We performed genome-wide Y2H screens as well as targeted Y2H analyses for specific interactions involving components of the Sec and Tat secretion machineries of B. subtilis, revealing an intricate protein-protein interaction network involving 71 proteins. Furthermore, three proteins identified in the Tat network, WprA, CsbC and HemAT, were shown to be important for effective protein secretion via the B. subtilis Tat system, indicating that our yeast two hybrid assays reveal biologically significant interactions involving membrane proteins. The studies provide a novel proteomic view on the interaction network of the secretion systems of B. subtilis
Anderson, James. "A comparison of four change detection techniques for two urban areas in the United States." Morgantown, W. Va. : [West Virginia University Libraries], 2002. http://etd.wvu.edu/templates/showETD.cfm?recnum=2371.
Full textTitle from document title page. Document formatted into pages; contains ix, 61 p. : col. ill., col. maps. Includes abstract. Includes bibliographical references (p. 40-42).
Sanchez, Dyana. "Etude structurale et fonctionnelle de la régulation de la compétence et du processus de transformation chez Streptococcus pneumoniae." Thesis, Université Paris-Saclay (ComUE), 2015. http://www.theses.fr/2015SACLS050.
Full textThe natural genetic transformation contributes to the maintenance and the evolution of the genomes in bacteria; it is a key mechanism to adapt to their environment. It allows the integration of exogenous DNA into the bacterial chromosome by homologous recombination during a particular state called competence.My thesis focused on the regulation of the competence state in S. pneumoniae (ComD, ComE), and on the interactions between the proteins involved in the uptake, the processing and recombination of exogenous DNA (DprA, RecA). In this bacterium, the opening of the competence is under the control of the two-component system ComD-ComE, who induces the transcription of target genes. DprA is one of the protein induced during the competence state, it is very conserved into the bacterial kingdom, and is involved in the closure of competence via direct interaction with ComE. DprA is also a key transformation protein involved in processing the incoming DNA, protection against nucleases, and recruitment of the RecA recombinase. SAXS analysis of the ComD-ComE, resolution of the crystallographic structure of ComE REC domain study of the interactions between ComE and its promoter regions allowed us to understand the choreography of competence opening in S. pneumoniae. Meanwhile, we studied spDprA interactions with DNA and with RecA. These data allowed us to propose an interaction model between DprA and RecA in S. pneumoniae and to propose a mechanism for RecA's loading on the ssDNA by DprA. I focused too on H. pylori DprA participating on the resolution of the 3D structure of the C-terminal domain by NMR and studying its interaction with the dsDNA
Allam, Sabry. "Acoustic modelling and testing of advanced exhaust system components for automotive engines." Doctoral thesis, KTH, Aeronautical and Vehicle Engineering, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-49.
Full textThe increased use of the diesel engine in the passenger car, truck and bus market is due to high efficiency and lower fuel costs. This growing market share has brought with it several environmental issues for instance soot particle emission. Different technologies to remove the soot have been developed and are normally based on some kind of soot trap. In particular for automobiles the use of diesel particulate traps or filters (DPF:s) based on ceramic monolithic honeycombs are becoming a standard. This new exhaust system component will affect the acoustics and also work as a muffler. To properly design exhaust systems acoustic models for diesel particulate traps are needed. The first part of this thesis considers the modelling of sound transmission and attenuation for traps that consist of narrow channels separated by porous walls. This work has resulted in two new models an approximate 1-D model and a more complete model based on the governing equations for a visco-thermal fluid. Both models are expressed as acoustic 2-ports which makes them suitable for implementation in acoustic software for exhaust systems analysis. The models have been validated by experiments on clean filters at room temperature with flow and the agreement is good. In addition the developed filter models have been used to set up a model for a complete After Treatment Device (ATD) for a passenger car. The unit consisted of a chamber which contained both a diesel trap and a Catalytic Converter (CC). This complete model was also validated by experiments at room temperature. The second part of the thesis focuses on experimental techniques for plane wave decomposition in ducts with flow. Measurements in ducts with flow are difficult since flow noise (turbulence) can strongly influence the data. The difficulties are also evident from the lack of good published in-duct measurement data, e.g., muffler transmission loss data, for Mach-numbers above 0.1-0.2. The first paper in this part of the thesis investigates the effect of different microphone mountings and signal processing techniques for suppressing flow noise. The second paper investigates in particular flow noise suppression techniques in connection with the measurement of acoustic 2-ports. Finally, the third paper suggests a general wave decomposition procedure using microphone arrays and over-determination. This procedure can be used to determine the full plane wave data, e.g., the wave amplitudes and complex wave numbers k+ and k-. The new procedure has been applied to accurately measure the sound radiation from an unflanged pipe with flow. This problem is of interest for correctly determining the radiated power from an engine exhaust outlet. The measured data for the reflection coefficient and end correction have been compared with the theory of Munt [33] and the agreement is excellent. The measurements also produced data for the damping value (imaginary part of the wavenumber) which were compared to a model suggested by Howe [13]. The agreement is good for a normalized boundary layer thickness less than 30-40