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Kraft, Steven. "The Characterization of the Effects of Stress Concentrations on the Mechanical Behavior of a Micronic Woven Wire Mesh." Master's thesis, University of Central Florida, 2013. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/5655.
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Woven structures are steadily emerging as excellent reinforcing components in dual-phase composite materials subjected to multiaxial loads, thermal shock, and aggressive reactants in the environment. Metallic woven wire mesh materials display good ductility and relatively high specific strength and specific resilience. While use of this class of materials is rapidly expanding, significant gaps in mechanical behavior classification remain. This thesis works to address the mechanics of material knowledge gap that exists for characterizing the behavior of a metallic woven structure, composed of stainless steel wires on the order of 25 microns in diameter, and subjected to various loading conditions and stress risers. Uniaxial and biaxial tensile experiments, employing Digital Image Correlation (DIC) as a strain measurement tool, are conducted on woven wire mesh specimens incised in various material orientations, and with various notch geometries. Experimental results, supported by an ample analytic modeling effort, indicate that an orthotropic elastic constitutive model is reasonably capable of governing the macro-scale elasticity of the subject material. Also, the Stress Concentration Factor (SCF) associated with various notch geometries is documented experimentally and analytically, and it is shown that the degree of stress concentration is dependent on both notch and material orientation. The Finite Element Method (FEM) is employed on the macro-scale to expand the experimental test matrix, and to judge the effects of a homogenization assumption when modeling metallic woven structures. Additionally, plasticity of the stainless steel woven wire mesh is considered through experimental determination of the yield surface, and a thorough analytic modeling effort resulting in a modified form of the Hill yield criterion. Finally, meso-scale plasticity of the woven structure is considered, and the form of a multi-scale failure criterion is proposed and exercised numerically.M.S.M.E.
Masters
Mechanical and Aerospace Engineering
Engineering and Computer Science
Mechanical Engineering; Mechanical Systems
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Johansson, Christian, and Marcus Karlsson. "Characterisation of a data transmission link." Thesis, Linköping University, Department of Science and Technology, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-2359.
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This report is the result of a Master Thesis work that has been performed between October 2003 and March 2004. The purpose of the work was to evaluate a part of the signal chain in a product of Micronic Laser Systems AB. The evaluation was performed to obtain the characterisation for the signal chain, such as impedances and crosstalk.
The work started with a literature study in order to refresh and increase the knowledge that was needed before the practical work. Then measurements, computer aided simulations and comparisons between these were performed.
Measurements were performed using TDR (Time Domain Reflectometry). The results showed the impedance levels along the signal chain. This was interesting since it showed how well the different parts in the system are matched. Unmatched parts result in reflections that disturb the transmitted signal and contribute to crosstalk, which also was measured.
Simulations were done using ADS (Advance Design System), a tool from Agilent Technologies Inc. A substantial part of the simulation work was to build models of the real system. These models have been used for simulation. The simulation results were then compared to the measurement results.
The results show that the system can be better matched concerning the channel impedance. There are large variations in impedance levels along the signal chain, resulting in signal reflections. Another effect studied is crosstalk between channels. Measurements and simulations showed the presence of crosstalk but it seems to be a minor problem in the current machine.
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Kempe, Marcus, and Carl Åbjörnsson. "Navigation, Visualisation and Editing of Very Large 2D Graphics Scenes." Thesis, Linköping University, Department of Science and Technology, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-2684.
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The project has been carried out at, and in association with, Micronic Laser Systems AB in Täby, Sweden. Micronic Laser Systems, manufacture laser pattern generators for the semiconductor and display markets. Laser pattern generators are used to create photomasks, which are a key component in the microlithographic process of manufacturing microchips and displays.
An essential problem to all modern semiconductor manufacturing is the constantly decreasing sizes of features and increasing use of resolution enhancement techniques (RET), leading to ever growing sizes of datasets describing the semiconductors. When sizes of datasets reach magnitudes of hundreds of gigabytes, visualisation, navigation and editing of any such dataset becomes extremely difficult. As of today this problem has no satisfying solution.
The project aims at the proposal of a geometry engine that effectively can deal with the evergrowing sizes of modern semiconductor lithography. This involves a new approach to handling data, a new format for spatial description of the datasets, hardware accelerated rendering and support for multiprocessor and distributed systems. The project has been executed without implying changes to existing data formats and the resulting application is executable on Micronics currently existing hardware platforms.
The performance of the new viewer system surpasses any old implementation by a varying factor. If rendering speed is the comparative factor, the new system is about 10-20 times faster than its old counterparts. In some cases, when hard disk access speed is the limiting factor, the new implementation is only slightly faster or as fast. And finally, spatial indexing allow some operations that previously lasted several hours, to complete in a few seconds, by eliminating all unnecessary disk-reading operations.
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BLOCH, KARINE. "Contribution a l'etude des clusters de malformations : analyse d'un pic d'incidence d'anotie/microtie observe dans la region rhone-alpes en 1987 : travail realise dans le cadre de l'institut des genomutations." Lyon 1, 1989. http://www.theses.fr/1989LYO1M418.
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Paccola, Elaine Cristina Moreto. "Sistema de frequência modulada e malformação de orelha: benefício e efeito do uso no ambiente educacional." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/25/25143/tde-24012019-085000/.
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As malformações congênitas de orelha causam dificuldades auditivas, interferindo no desenvolvimento das habilidades de fala e linguagem e, consequentemente, prejudicando o desenvolvimento social, emocional, cognitivo e acadêmico da criança. Para minimizar estas dificuldades, o aparelho de amplificação sonora individual (AASI) por condução óssea é indicado. Com a possibilidade de adaptação do sistema de frequência modulada (FM) pelo SUS, de acordo com a portaria n° 1.274 do Ministério da Saúde, de 25 de junho de 2013, o objetivo deste trabalho foi avaliar o benefício deste dispositivo em crianças e adolescentes com malformação de orelha externa e/ou média, usuários de AASI por condução óssea, sob a ótica dos próprios usuários, seus pais e professores. Participaram da pesquisa vinte e quatro crianças e adolescentes, doze pais ou responsáveis e doze professores. Foram utilizados os instrumentos: Listas de Sentenças em Português, para avaliar a percepção de fala no ruído e Classroom Participation Questionnaire (CPQ), para a auto avaliação da participação em sala de aula (usuários); Questionário Avaliação do Sistema FM, para avaliar o desempenho em diferentes situações auditivas (pais) e Screening Instrument For Targeting Educational Risk in Secondary Students (SIFTER), para a avaliação do desempenho acadêmico (professor). Todas as avaliações foram realizadas nas condições com e sem o sistema de FM e para a comparação dos resultados foi utilizado o teste t pareado. Em todos os procedimentos estatísticos foi adotado nível de significância de 5% (p<0,05). Foi observada diferença significante com o uso do sistema de FM para todos os aspectos avaliados, evidenciando o benefício da adaptação deste dispositivo para esta população.Congenital ear malformations cause hearing impairment, interfering with speech and language development, and, consequently, impairing the social, emotional, cognitive and academic development of the child. Bone conduction hearing aids are indicated to minimize these difficulties. With the possibility of fitting the FM System by the Brazilian Health Public System, according to the ordinance no. 1,274 from the Ministry of Health, dated June 25, 2013, this study aimed to evaluate the benefit of the FM System in children and adolescents with external ear and/or middle ear malformation, users of bone conduction hearing aids, through the perspective of the users, their parents and teachers. Twenty-four children and adolescents, twelve parents or guardians, and twelve teachers participated in this study. The instruments used were: Sentence Lists in Brazilian Portuguese, to evaluate speech perception in noise, and Classroom Participation Questionnaire (CPQ), for self-assessment of classroom participation (users); FM System Evaluation Questionnaire, to evaluate performance in different auditory situations (parents); and Screening Instrument for Targeting Educational Risk in Secondary Students (SIFTER), to evaluate academic performance (teachers). All evaluations were performed with and without the FM System, and the paired t-test was used to compare the results. A significance level of 5% was adopted (p<0.05) in all statistical tests. A significant difference was observed with the use of the FM system in all aspects evaluated, demonstrating the benefit of fitting this device in this population.
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O'Brien, Graham James. "Molecular analysis of microcin 24 : Genetics, secretion and mode of action of a novel microcin." Thesis, University of Canterbury. Plant and Microbial Sciences, 1996. http://hdl.handle.net/10092/6808.
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Colicins and microcins are proteinaceous antimicrobial agents produced by members of the Enterobacteriaceae which are active against other members of this family. Colicin24 is a novel bacteriocin produced by a uropathogenic strain of Escherichia coli isolated at Christchurch Hospital. Through detailed genetic analysis of the DNA encoding this toxin and assaying the toxic activity, colicin 24 was re-classified as microcin 24 and has been shown to have a similar genetic organisation to that of colicin V and a novel mode of activity.
The region of DNA encoding microcin 24 was subcloned from pGOB34 into pBR322 generating pGOB18 (5.44kb). Mutagenesis, DNA sequencing and transcomplementation identified two regions with high sequence similarity and functional homology to the ColV transporters CvaA and CvaB. The insert DNA of pGOB18 was sequenced in both directions and has been found to contain 5267bp encoding five open reading frames, mdbA, mtft, mtfS, mtfA and mtfB, forming three operons mdbA, mtfI/mtfS and mtfA/mtfB all of which were transcribed in the same direction. The predicted protein products of all the open reading frames except mtfB were confirmed by expressing the genes in minicells. Further mutagenesis and trans-complementation has identified mdbA as a cis acting positive regulatory gene with sequence similarity to the histone-like proteins. The mtfI and mtfS genes were confirmed as the Mcc24 immunity gene and the Mcc24 structural gene respectively. The genes mtfA and mtfB were found to encode the transport proteins homologous to CvaA and CvaB respectively, with mtfB encoding a protein which is a member of the ABC family of bacterial transporters. Transport also requires the TolC outer membrane protein. Analysis of the mtfS DNA sequence has identified a double glycine leader sequence, making MtfS the second microcin after ColV to belong to this class of peptide antibiotics. Experimental evidence suggested that unlike ColV, Mcc24 is inactive within the producing cell, however both toxins require the ABC transporter for post-translational modification of the pre-peptide.
The regulation of Mcc24 synthesis is controlled by the interaction between σs, Fur, and MdbA, encoded by the mdbA gene. Analysis of the promoter sequences has identified putative regions of DNA bending which might facilitate the binding of σs and MdbA. A Fur-box with good sequence similarity to the consensus Fur-box has been identified in the mtfI/mtfS promoter and is the proposed site for Fur binding.
The activity spectrum of Mcc24 is restricted to enteric bacteria and SernA, the MccE492 receptor, is also required as the receptor for Mcc24. Extracts of Mcc24 have been found to degrade both linearised and covalently closed circular DNA in vitro. The activity is absent in extracts from mtfS - strains, suggesting that Mcc24 inhibits the growth of sensitive cells by degrading DNA. The effect of Mcc24 expression on the virulence of E. coli was tested using the embryo lethality assay, however unlike ColV which increases the virulence of strains, the expression of Mcc24 did not appear to have a significant effect on E. coli virulence in this system.
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Stambazzi, Fabio. "Biosintesi di carotenoidi di origine microbica." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2019.
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L'interesse per i carotenoidi è aumentato considerevolmente, principalmente a causa: dei benefici per la salute umana, gli integratori alimentari, l'industria alimentare (coloranti) e prodotti farmaceutici. La produzione di carotenoidi attraverso la sintesi chimica o l'estrazione dalle piante, è limitata da basse rese che si traducono in alti costi di produzione. Inoltre, alcuni dei sottoprodotti derivanti da tali processi chimici, possono avere effetti collaterali indesiderati sul consumo. Questo porta alla ricerca della produzione microbica di carotenoidi (sintesi microbica), come alternativa che ha mostrato rendimenti migliori. In questo lavoro, sono state raccolte e analizzate le evidenze scientifiche più recenti nell’ambito della biosintesi dei carotenoidi da parte dei microrganismi, anche al fine di valutare il potenziale della ricerca biotecnologica in tale ambito. La produzione biotecnologica offre vantaggi economici, rispetto ai carotenoidi vegetali sintetici o estratti, grazie all'uso di substrati a basso costo (rifiuti agroindustriali) ed è più sicura ed efficiente rispetto ai metodi tradizionali. Molti microrganismi, soprattutto i lieviti come Rhodotorula spp, Xanthophyllomyces dendrorhous, Sacharomyces cerevisiae e Candida utilis o funghi appartenenti alle specie Blakeslea trispora e Phycomyces blakesleeanus, hanno dimostrato di essere produttori di grandi quantità di carotenoidi e hanno mostrato un'importante capacità di crescita nei rifiuti agroindustriali. La tecnologia moderna, come l'uso del DNA ricombinante, unita all'isolamento di alcuni dei geni vitali coinvolti nella biosintesi dei carotenoidi, hanno incoraggiato la ricerca sulla produzione dei carotenoidi. Nell’ambito dei batteri, sono stati studiate alcune specie che si sono rivelate particolarmente promettenti nell’ambito del genere Stafilococcus e Lactobacillus plantarum tra i batteri lattici. La produzione microbica di carotenoidi ha un notevole potenziale di mercato e industriale.
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Chodosovskaja, Ala. "Mikrobinė metalų korozija natūralią aplinką imituojančiomis sąlygomis." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2005. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2005~D_20050613_185604-32321.
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Corrosion behaviour of Al, Zn, Cu and steel samples under the conditions of constant temperature and humidity were performed in the media containing the following microorganisms. Bacillus mycoides, Aspergillus fumigatus Aspergillus niger, Cladosporium herbarum, Penicillium frequentans. The influence of metal surface morphology on the vitality of microorganisms was investigated, as well as the proceeding of microbial corrosion was under the study. The real surface area of Cu electrode was determined by means of electrochemical techniques, while the method for comparison of surface areas of other metals was proposed and this method was based on atomic force microscope measurements. It was determined that the metal nature and morphology influenced the vitality of microorganisms. The results of electrochemical impedanse spectroscopy enabledus to evaluate the corrosion behaviour of metals. The results were found to indicate the corrosion inhibition for Al, steel and Cu, however, the effect depended on the metal surface morphology and exposure time.
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DOMINGOS, E. "Desenvolvimento de Novos Métodos Analíticos em Química Forense e Petroleômica por Espectrometria de Massas Ambiente (Paper Spray) e Espectroscopia Portátil na Região do Infravermelho Próximo (MICRONIR)." Universidade Federal do Espírito Santo, 2017. http://repositorio.ufes.br/handle/10/7360.
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Previous issue date: 2017-11-30Com o advento de uma nova família de técnicas de ionização, a espectrometria de massas (MS) ambiente foi introduzida como uma maneira simples de gerar íons na MS. Entre elas, a técnica de ionização por paper spray (PS) demonstrou-se versátil para resolver inúmeros problemas. Neste trabalho, a técnica de PS-MS no modo de ionização positiva (PS(+)-MS) foi aplicada em três subáreas da química forense: drogas de abuso e documentoscopia e ervas fitoterápicas. Na primeira, a técnica PS-(+)-MS determinou o perfil químico de drogas sintéticas tais como selos contendo 25I-NBOMe (2-(4-iodo-2,5-dimetoxifenil)-n-[(2-Metoxifenil) metil] etamina), extratos e folhas de canabinóides naturais (Δ9-THC) e canabinóides sintéticos (JWH-073; 5F-AKB48; JWH-122; JWH-250; e JWH-210). Em todos os casos, as moléculas foram facilmente detectadas na sua forma protonada ([M+H]+) com resolução, m/Δm50% = 67,000 e uma precisão de massa menor que <2 ppm. O desempenho da técnica PS(+)-MS foi comparado com o de outras fontes de ionização: leaf Spray (LS-MS) e eletrospray (ESI-MS). Além disso, um método foi desenvolvido para quantificar uma série de drogas ilícitas (de 1 a 110 𝜇g L-1, com linearidade de R2> 0,99). Em documentoscopia, a técnica PS(+)-MS foi capaz de obter com sucesso o perfil químico de diferentes canetas vendidas no comercio. A intensidade relativa (RII372) do corante azul de metileno foi monitorada para discriminar os cruzamentos de traços de canetas e, até a data, os documentos questionados. O perfil químico das notas brasileiras de segunda geração de R$ 100,00 (reais) também foi explorado. A técnica PS(+)-MS foi capaz de classificar as notas em autêntico ou falsificadas. Constatando que amostras falsas possuem um perfil químico similar às notas caseiras da impressora Deskjet®. Finalmente, aplicamos PS(+)-MS para verificar a autenticidade de ervas usadas para perda de peso. Quinze diferentes medicamentos à base destas ervas foram analisados por PS(+)-MS. Encontrando diferentes tipos de compostos: sibutramina (m/z 280), cafeína (m/z 195), glicose (m/z 203 [M+Na], m/z 219 [M+K] e sacarose (m/z 381 [M+K]). Todas essas substâncias não estavam listadas em seus rótulos. Em geral, a técnica PS(+)-MS mostrou ser uma excelente ferramenta analítica em química forense. O segundo estudo abordado foi o controle de qualidade de combustíveis com aplicação do micro-espectrômetro portátil na região do infravermelho próximo (MICRONIR). Neste trabalho, verificou-se a potencialidade do MICRONIR no controle da qualidade do combustível. Assim, modelos quimiométricos (usando o PLS - regressão por mínimos quadrados parciais) foram desenvolvidos para quantificar biodiesel em Diesel (LD=0,5 wt%; LQ=1,8 wt%, e RMSEP=1.8 wt%); enxofre em Diesel (LD=2,4 mg L-1; LQ=8,0 mg L-1, e RMSEP=13,2 mg L-1); gasolina, etanol e metanol em gasolina tipo C (LDgas=0,55 wt%; LQgas=1,84 wt%, e RMSEPgas=0,81 wt%; LDet=0,75 wt%; LQgas=2,50 wt%, e RMSEPeth=3,81 wt%; LDmet = 0,85 wt%; LQmet = 2,84 wt%, e RMSEPmet = 1,80 wt%); e água, metanol e etanol em etanol combustível hidratado (LDH2O = 0,04 wt%; LQH2O=1,29 wt%, e RMSEPH2O=1,05 wt%; LDmet= 0,52 wt%; LQmet = 1,73 wt%, e RMSEPmet =2,78wt %; LDet=1,22 wt%; LQet=4,07 wt%, e RMSEPet= 4,41 wt%). O método proposto apresentou alta precisão e exatidão em todos os casos, e os resultados mostraram que a técnica MICRONIR teve excelente desempenho no controle da qualidade do combustível.
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Debas, Hélène. "Émulsification en systèmes microstructurés." Thesis, Vandoeuvre-les-Nancy, INPL, 2009. http://www.theses.fr/2009INPL075N/document.
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Cette thèse, intitulée « Emulsification en systèmes microstructurés », s’inscrit au sein de la tâche « Emulsification contrôlée » du projet européen IMPULSE. Deux micromélangeurs en acier inoxydable, un V-type et un Caterpillar, ont été testés en utilisant un pilote d’émulsification continue. Ces dispositifs conçus en acier inoxydable et fonctionnant comme des boîtes noires, des micromélangeurs transparents ont ensuite été utilisés afin de comprendre leurs mécanismes d’émulsification. Les paramètres-clés intervenant dans la formation de gouttes à un orifice à l’échelle macroscopique ont dans un premier temps été identifiés. A l’échelle microscopique, la formation des gouttelettes dans le micromélangeur V-type est issue de la mise en contact des jets des phases aqueuse et organique formés à la sortie de ce dispositif et d’un phénomène élongationnel avec des instabilités interfaciales. Dans le cas du Caterpillar, la taille des gouttelettes dépend de la géométrie interne des éléments en série de ce micromélangeur. La formation des gouttelettes est issue d’un phénomène de cisaillement au niveau de la jonction en Y. La réduction de la taille de ces gouttelettes est ensuite due à leur passage dans les éléments de mélange. L’utilisation de micromélangeurs transparents a, quant à elle, permis de caractériser davantage ces deux micromélangeurs par micro-PIV et caméra rapide. Enfin, une dépendance du diamètre des gouttelettes par rapport à l’énergie dissipée est constatée pour le Caterpillar mais par pour le V-type. L’énergie dissipée dans ces deux micromélangeurs semble être moindre et les émulsions formées de meilleure qualité par rapport aux procédés classiques d’émulsificationThis thesis, entitled “Emulsification in micromixers” was carried out within the framework of the Task “Controlled Emulsification” of the European IMPULSE project. Two micromixers in stainless steel, the V-type and the Caterpillar, were tested in an experimental setup. These microdevices working as black boxes, transparent micromixers were used after to gain insight into the fundamental mechanisms for emulsification. Firstly, the key parameters enabling the drop formation at macroscopic scale were identified. At microscopic scale, the droplet formation in the V-type micromixer results from the contact of aqueous and organic phases jets at the outlet of the microdevice and from elongational phenomena with interfacial instabilities. In the case of the Caterpillar, the droplets size depends on the internal geometry of the microdevice. The droplet formation can be mainly attributed to the shearing phenomena at the Y-junction. The decrease of the droplets’ size is then due to their passage through the mixing elements in series in the outlet channel. Moreover, the use of transparent micromixers allows to characterize these two micromixers by the micro-PIV and high speed camera. A straightforward relationship between the energy dissipation and the size of droplets was established for the Caterpillar, but not for the V-type. Moreover, the energy dissipation within these two micromixers is lower and the emulsions obtained having a more satisfactory quality than in the case of the classical emulsification processes
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Grønli, Marius. "Equity research - Micron Technology." Master's thesis, Instituto Superior de Economia e Gestão, 2019. http://hdl.handle.net/10400.5/19436.
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Mestrado em FinançasEste projeto é o trabalho final como parte do mestrado. Licenciatura em Finanças pela Escola de Economia e Gestão de Lisboa (ISEG). Os alunos podem optar por escrever uma tese de mestrado ou escrever uma pesquisa de patrimônio de uma empresa escolhida. O projeto está estruturado de acordo com as diretrizes do ISEG e o CFA institui recomendações de relatórios de pesquisa. Eu escolhi analisar a Micron Technology Inc. por causa do meu interesse no setor de tecnologia, especialmente na indústria de semicondutores. O setor exibe muitos traços especiais, como ciclicidade e exigências extremas de capital, que eram ao mesmo tempo educacionais e exigentes para análise.
This project is the final work as a part of the MSc. Finance degree at Lisbon School of Economics and Management (ISEG). Students can choose to write a master thesis or write an equity research of a chosen company. The project is structured after ISEG's guidelines and the CFA institutes research report recommendations. I choose to analyze Micron Technology Inc. because of my interest in the technology sector, especially the semiconductor industry. The industry displays a lot of special traits like cyclicality and extreme capital requirements, which was both educational and demanding to analyze.
info:eu-repo/semantics/publishedVersion
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Zurek, Eduardo. "System optimization for micron and sub-micron particle identification using spectroscopy-based techniques." [Tampa, Fla] : University of South Florida, 2006. http://purl.fcla.edu/usf/dc/et/SFE0001635.
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Sreedharan, Nair Shree Narayanan. "MicroGC: Of Detectors and their Integration." Diss., Virginia Tech, 2014. http://hdl.handle.net/10919/47785.
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Gaseous phase is a critical state of matter around us. It mediates between the solid crust on earth and inter-stellar vacuum. Apart from the atmosphere surrounding us where compounds are present, natively, in a gaseous phase, they are also trapped within soil and dissolved in oceanic water. Further, those that are less volatile do enter the gaseous phase at high temperatures. It is this gaseous phase that we inhale every second. It is thus critical that we possess the tools to analyze a mixture of gaseous compounds. One such method is to separate the components in time and then identify, primarily based on the retention times, also known as gas chromatography.
This research focuses on the development of gas detectors and their integration, in different styles, primarily for gas chromatography. Utilizing fabrication techniques used in semiconductor industry and exploiting scaling laws we investigate the ability to improve on conventional gas separation and identification techniques. Specifically, we have provided a new spin to the age-old thermal conductivity detector enabling its monolithic integration with a separation column. A reference-less, two-port integration architecture and a one-of-its-kind released resistor on glass are some of its salient features. The operation of this integrated device with a preconcentrator and in a matrix array was investigated. The more unique contribution of this research lies in the innovative discharge ionization detector. An ultra-low power, sensitive, easy to fabricate detector, it requires more investigation for a thorough understanding and will likely mature to replace the thermal conductivity detector, as the detector of choice for universal detection, in time to come.Ph. D.
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Griffith, Saul Thomas 1974. "Towards personal fabrications : tabletop tools for micron and sub-micron scale functional rapid prototyping." Thesis, Massachusetts Institute of Technology, 2000. http://hdl.handle.net/1721.1/17521.
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Thesis (S.M.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2001.Includes bibliographical references (leaves 78-81).
Three tools for the rapid prototyping of micron and sub-micron scale devices are presented. These tools represent methods for the manufacture of PEMS, or Printed micro Electro Mechanical Systems, and are enabled because they exploit the novel properties of nanocrystalline materials and their interactions with energetic beams. UV contact mask lithography was used to directly pattern metallic nanocrystals on glass and polyimide surfaces without vacuum or etching processes or the use of photoresist layers. Direct electron beam lithography of nanocrystalline metals was used to pattern multiple layer, multiple material, structures with minimum feature sizes of 100nm. Finally a micro-mirror array based selective laser sintering apparatus was built for the rapid, maskless patterning of PEMS. This tool was used to directly pattern metal structures, and for the rapid manufacture of elastomeric stamps for "nano embossing". Minimum feature sizes under 10 microns were achieved and routes to 2 micron features described. Processing time was reduced to hours from the weeks for traditional photomask / photolithography based systems. These tools are examined in the greater context of rapid prototyping technologies.
Saul Griffith.
S.M.
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Hadaoui, Samira. "Caratterizzazione della popolazione microbica di salami fermentati spontaneamente." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2016. http://amslaurea.unibo.it/11489/.
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Le fermentazioni spontanee nei salami sono un fenomeno molto complesso in cui si assiste ad una successione di diverse popolazioni microbiche (micrococchi, stafilococchi e batteri lattici), avente ognuna un ruolo importante nell’ottenimento delle qualità desiderate del prodotto finale. Questo susseguirsi vorticoso di popolazioni microbiche nelle fermentazioni spontanee viene ormai regolamentato dall’uso di colture starter che, aggiunte in quantità idonee immediatamente prima dell’insaccamento, contribuiscono in maniera essenziale ad un rapido, corretto (e soprattutto sicuro) processo di fermentazione prima e di disidratazione poi. Poiché però l’impiego di starter segue spesso protocolli indifferenziati, è importante la selezione di colture starter “taylor made”, in grado di differenziare i prodotti in maniera riconoscibile con l’apporto di specifici tratti organolettici e sensoriali. Dunque, con questo elaborato di tesi si è voluto procedere alla raccolta di potenziali colture starter provenienti da diversi salami della tradizione mediterranea (salame di tipo bresciano, romagnolo e lucano), fermentati spontaneamente. Questi prodotti sono stati dapprima caratterizzati per quanto riguarda le loro caratteristiche microbiologiche, chimico-fisiche, profilo aromatico e il loro contenuto in ammine biogene. Successivamente, in particolare per il salame di tipo bresciano, sono stati isolati ceppi di interesse dalla popolazione lattica, poi identificati e testati per alcune caratteristiche di interesse tecnologico (capacità di produrre ammine biogene e profilo aromatico). I ceppi riscontrati, appartenenti alle specie Lactobacillus sakei e Lactobacillus curvatus, hanno mostrato una notevole biodiversità, soprattutto per quanto riguarda la produzione di molecole aromatiche, e quindi una notevole capacità, anche nell’ambito della stessa specie, di modulare la produzione di composti molto importanti dal punto di vista organolettico.
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Sotelo-Salazar, Salvador. "Instruction scheduling in micronet-based asynchronous ILP processors." Thesis, University of Edinburgh, 2003. http://hdl.handle.net/1842/14457.
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Sublett, Jacob D. "Effects of seed coat variation and population on plant-microbial interactions." Bowling Green State University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1467569697.
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Liu, Yuchen. "Invasion of Babesia microti in Northeastern USA." Thesis, Uppsala universitet, Institutionen för biologisk grundutbildning, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-172530.
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Kim, Yong-Rae. "Integrated Uv-Vis Multiangle-Multiwavelength Spectrometer For Characterization Of Micron And Sub-Micron Size Particles." Scholar Commons, 2004. https://scholarcommons.usf.edu/etd/723.
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Characterization of micron and sub-micron size particles requires the simultaneous measurement of the joint particle property distribution (JPPD). The JPPD is comprised of particle size, shape, orientation, composition, optical properties, and surface properties. Measurement of each of the particle properties independently is a difficult task and it has been only partially successful. To determine as many particle properties as possible using optical methods it is necessary to simultaneously measure all aspects of the interaction of the incident light with the particles of interest. This approach leads to the concept of multidimensional spectroscopy suggested by Prof. Garcia-Rubio. Dr. Bacon proved the proposition by developing and testing a prototype multianglemultiwavelength (MAMW) spectrometer proposed by Prof. Garcia-Rubio. However, the prototype MAMW spectrometer has limitations in the amount of information it can obtain because of strong absorption of deep UV light and detector saturation due to the use of optical fibers and single integration time for the CCD detector.
The Integrated UV-VIS MAMW spectrometer has been developed to overcome the limitations of the prototype MAMW spectrometer. Improvements have become possible through the use of UV lenses and integration time multiplexing (ITM). The Integrated UV-VIS MAMW spectrometer has the capabilities to perform low angle scattering measurements starting from 4o with simultaneous detection of multiwavelength light from 200 nm to 820 nm, UV-VIS transmission spectroscopy, and frequency domain fluorescence spectroscopy. Following the development, possible sources of errors were analyzed and data calibration procedures have been established to ensure the validity and reproducibility of the measurement results.
The capabilities of the Integrated UV-VIS MAMW spectrometer were tested by measuring UV-VIS MAMW spectra of polystyrene standards. The measured UV-VIS MAMW spectra clearly show differences due to particle size, shape, and compositional changes. Measurements of the UV-VIS MAMW spectra of sickled whole blood samples demonstrate that particle shape and compositional changes can be detected simultaneously. These results confirmed that the Integrated UV-VIS MAMW spectrometer could be a powerful tool for the characterization of micron and sub-micron size particles. Alternate approaches to enhance these capabilities further, i.e., the development of a new multidimensional MAMW spectrometer, are also described.
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BORTOLINI, CRISTIAN. "Caratterizzazione della diversità microbica in fave di cacao fermentate." Doctoral thesis, Università Cattolica del Sacro Cuore, 2017. http://hdl.handle.net/10280/19074.
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La qualità delle fave di cacao disponibili in commercio, che rappresentano la principale materia prima per la produzione di cioccolato, dipende da diversi fattori inclusi: il tipo di piantagione, le pratiche agricole ed il processo di post raccolta. Tra queste; fermentazione ed essicazzione sono generalmente considerate le più rilevanti, dal momento in cui, durante queste fasi, vengono formati e fissati i precursori degli aromi del cacao. Inoltre, esse rappresentano un step cruciale durante il quale possono verificarsi contaminazioni da parte dei funghi filamentosi. La fermentazione è caratterizzata da una successione ben definita di lieviti, batteri lattici e batteri acetici, a tal fine, lo scopo del presente lavoro di tesi è stato quello di esplorare e descrivere in modo completo le comunità batteriche e fungine coinvolte nella fermentazione delle fave di cacao e valutare se l’origine geografica ed il metodo di fermentazione potessero influenzare la loro composizione. Per ottenere tali risultati il gene 16s rRNA è stato usato come marker per descrivere la comunità batterica totale mediante High Throughput Sequencing (HTS), dimostrando come tale approccio abbia la capacità di evidenziare la totalità delle comunità batteriche a livello di specie. In un secondo approccio l’Internal Transcribed Spacer 1 (ITS1) ed il dominio D1/D2 della sub unità maggiore dell’RNA ribosomiale (26s rRNA) sono stati selezionati per descrivere la popolazione fungina. I risultati hanno evidenziato come le due regioni abbiano la capacità di descrivere la composizione generale delle popolazioni, sebbene il dominio D1/D2 sia stato in grado di analizzare più nel dettaglio la composizione. Infine gli stessi campioni sottoposti all’analisi mediante HTS sono stati analizzati mediante SPME-GC-MS per evidenziare i principali composti aromatici formatisi durante il processo di post raccolta.
Complessivamente i risultati indicano chiaramente che l’approccio mediante HTS ha le potenzialità per fornire una dettagliata visione d’insieme delle comunità batteriche e fungine presenti durante le fasi di post raccolta delle fave di cacao, inoltre le analisi statistiche hanno evidenziato come l’ITS1 ed i composti volatili possano essere utilizzati per la tracciabilità geografica.The quality of commercial cocoa beans, the principal raw material for chocolate production, depends on several factors including type of plantations, the agricultural practices and the post-harvest processing. Among these, fermentation and drying are generally considered the most relevant, since during these phases cocoa flavors precursors are formed and fixed. Furthermore, they represent crucial steps during which filamentous fungi contamination might occur. Fermentation is characterized by a well-defined succession of yeasts, lactic acid bacteria and acetic acid bacteria, so that, the aim of the described studies was to explore total bacterial and fungal communities involved in cocoa bean fermentation and to evaluate if geographical origin and fermentation method might affect their composition. To achieve these results, 16s rRNA gene was used as marker to assess the total bacterial community by using High Throughput Sequencing (HTS), indicating that this approach has the ability to provide a comprehensive view of the cocoa bean microbiota at the species level. In a second approach, Internal Transcribed Spacer 1 (ITS1) and the D1/D2 domain of the Large subunit (LSU) of the nuclear ribosomal RNA (26S rRNA) were screened to assess the total fungal community. Results revealed the ability of these two genomic regions to describe reliably the general composition, even if D1/D2domain was able to go deeper into the fungal composition resulting in a higher resolution. In the last approach the same samples subjected to HTS investigation were analyzed through SPME-GC-MS in order to underline the principal key-aroma compounds formed during the post-harvest processing. Overall, results point out clearly that HTS approach has the ability to provide a comprehensive view of the total bacterial and fungal communities, and statistical analyses have shown how analyses of ITS1 sequences and volatile compounds might be useful for the geographical traceability of the processed cocoa beans samples.
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Canora, Alice. "Studio del potenziale prebiotico degli alimenti con un modello intestinale in vitro e analisi multi-omiche." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2021. http://amslaurea.unibo.it/22359/.
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In questo lavoro ci siamo concentrati sullo studio di un pane arricchito col 4% (p/p) di sansa sgrassata di oliva (DOP) prodotto nell’ambito del progetto europeo H2020 EcoProlive.
La sansa di oliva sgrassata è un sottoprodotto derivante dalla produzione dell’olio di oliva ed è caratterizzata da un elevato contenuto di polifenoli, risulta interessante valutarne il potenziale prebiotico e l’impatto sul microbiota del colon umano. Per questo, i prodotti studiati sono stati sottoposti a digestione gastro duodenale e successivamente a fermentazione colonica distale nel modello intestinale in vitro MICODE (Multi-Unit In vitro Colon Model). Il campionamento è stato effettuato prima, durante e dopo 24 ore di fermentazione, al fine di eseguire analisi metabolomiche tramite SPME GCMS, sequenziamento genomico 16S attraverso MiSeq e quantificazione assoluta delle principali specie batteriche tramite qPCR.
Dai risultati di questo studio è possibile affermare che il prototipo di pane Eco 4% possiede un potenziale prebiotico più debole rispetto ai frutto-oligosaccaridi dell’inulina, ma più forte del suo pane di controllo privo di polifenoli aggiunti.
Durante il periodo di fermentazione Eco4% non ha influenzato l’eubiosi e non ha indotto la disbiosi. Inoltre sono stati registrati l’aumento dell’abbondanza di specie probiotiche o benefiche, come Lactobacillales e Bifidobacteriaceae e la diminuzione di specie opportunistiche o patogene.
Grazie all’analisi del volatiloma è stata riscontrata la produzione di composti bioattivi come gli acidi grassi a corta e media catena. Composti dannosi come gli acidi grassi a catena ramificata ed indolo e scatolo, invece, sono stati ridotti.
Questi risultati sono supportati da un approccio statistico multivariato in grado di combinare dati di genomica e di metabolomica microbica, in una vetrina multi-omica, a dimostrazione della visibile relazione causa-effetto generata da una certa fibra che possiede un potenziale prebiotico.
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Dubuget, Vincent. "Elaboration et caractérisation de matériaux ferromagnétiques doux : modélisation de couches magnétiques inhomogènes." Thesis, Tours, 2010. http://www.theses.fr/2010TOUR4003/document.
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Au cours de ce manuscrit sont reportées l’élaboration et la caractérisation de matériaux ferromagnétiques doux : les microfils nanocristallisés gainés de verre de composition Finemet élaborés par le procédé de tirage Taylor-Ulitovsky et les couches minces amorphes decomposition CoNb et CoZr déposées par pulvérisation cathodique assistée magnétron.Une première partie du travail de thèse a été consacrée à l’étude de l’influence de l’état structural et de la composition sur les propriétés magnétiques, respectivement au travers des microfils nanocristallisés gainés de verre et des couches minces amorphes. Une deuxième partie a été vouée à référencer les différentes sources de dispersion d’aimantation des couches minces magnétiques, élaborées au déroulé sur substrat polymère. Une méthode a été proposée afin de quantifier la distribution d’anisotropie en angle et en intensité dans l’épaisseur. Le comportement magnétique des telles couches a été modélisé en prenant en compte la distribution d’aimantation expérimentale dans une approximation den-macrospins sans interaction d’échange. Un second volet a consisté à développer un modèle micromagnétique unidimensionnel prenant en compte l’énergie d’échange. Ce modèle a été appliqué avec succès sur une bicouche et une multicouche à anisotropies magnétiques croisées, élaborées spécifiquement à cet effet. L’étude exhaustive d’une bicouche à anisotropies croisées a été menée : aimantation statique et dynamique, structure en domaines magnétiques, aimantation dynamiquement couplée et caractérisation du profil d’aimantation dans l’épaisseurThe aim of this work is to product and characterize some soft ferromagnetic materials : nanocrystallized Finemet-based glass-coated microwires fabricated using a Taylor-Ulitovskyprocess and amorphous Co-based thin films deposited by magnetron sputtering.In a first part, the influence of the structural order for the nanocrystallized glass-coatedmicrowires and the influence of the composition for the thin magnetic films on the magnetic properties has been studied.In a second part, the various origins of the magnetization dispersion of thin layers deposited continuously on a transported polymeric substrate has been listed. A method has been proposed to estimate both angular and intensity anisotropy distribution in depth. The magnetic susceptibility calculation taking into account the experimental magnetization dispersion is achieved in the framework of n-macrospins approximation without the exchange interaction. In addition, the static and dynamic magnetic behavior of both abilayer and a multilayer with crossed magnetic anisotropies has been reproduced by adedicated 1D micromagnetic model (with the exchange energy). In particular, a detailed study of such a bilayer has been investigated : static and dynamic magnetization, magnetic domain structure, coupled dynamically magnetization and characterization of the magnetization distribution in depth
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Arkili, Errol B. (Errol Bernard). "Gaseous flow in micron-sized channels." Thesis, Massachusetts Institute of Technology, 1994. http://hdl.handle.net/1721.1/12321.
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Guidash, R. Michael. "Development of a modular 2-micron BiCMOS process from an existing 2-micron n-well CMOS process /." Online version of thesis, 1991. http://hdl.handle.net/1850/11234.
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MISCHEL, ISABELLE. "La babesiose humaine." Strasbourg 1, 1992. http://www.theses.fr/1992STR15037.
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Vigren, David. "Identification of Environmental Plastic Samples from a Caribbean Beach Survey by Near-Infrared Spectroscopy with the MicroNIR and Chemometric Analysis." Thesis, Örebro universitet, Institutionen för naturvetenskap och teknik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-45772.
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MicroNIR is a portable near-infrared diffuse reflection spectroscope. Its suitability for identifying environmental plastic polymers was evaluated through a series of performance tests. The plastic samples were collected during a beach survey in the Caribbean. First a reference database was built by analysing a series of reference plastic polymers. Prediction models were constructed by using principal component analysis (PCA) and cluster analysis on 2D- and 3D-scatterplots. Measurements of samples with a surface area down to 1 mm2 were successfully identified with the prediction models. Blend spectra were created by measuring two polymers simultaneously, from which each polymer NIR-fingerprint were able to be individually extracted from the blend spectra by subtracting the NIR-fingerprint of the opposite polymer. Prediction models were used to identify the samples in the tests with household plastics and the environmental plastic samples, collected in the Caribbean. Out of the forty-eight samples collected forty (83%) were identified. Twenty-seven were identified as polyethylene (56%), eleven as polypropylene (23%), one as polystyrene (2%), and one as polyamide (2%).
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SALAMITOU, PHILIPPE. "Etude comparee des performances d'un lidar doppler coherent pulse pour la mesure du vent aux longueurs d'onde 2 microns et 10 microns." Paris 6, 1994. http://www.theses.fr/1994PA066756.
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Pour comparer les performances obtenues sur la mesure du vent, a l'aide d'un lidar doppler coherent pulse, aux deux longueurs d'onde 2 m et 10 m, une modelisation complete de l'instrument a ete developpee. Celle-ci prend en compte le bilan optique instrumental en detection coherente, l'interaction entre laser de sondage et atmosphere, et les performances du traitement du signal. Une methologie pour optimiser l'instrument est proposee. Elle conduit a la definition de concepts intrumentaux, pour les differentes applications pratiques du lidar vent. L'evaluation des performances de ces concepts permet de conclure sur les avantages respectifs des deux longueurs d'ondes considerees
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Franklin, Tracy A. "Efficient DCT blocks in sub micron CMOS." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0014/MQ52550.pdf.
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Roy, Indranil. "Algorithmic techniques for the micron automata processor." Diss., Georgia Institute of Technology, 2015. http://hdl.handle.net/1853/53845.
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Our research is the first in-depth study in the use of the Micron Automata Processor, a novel re-configurable streaming co-processor which is purpose-built to execute thousands of Non-deterministic Finite Automata (NFA) in parallel. By design, this processor is well-suited to accelerate applications which need to find all occurrences of thousands of complex string-patterns in the input data. We have validated this by implementing two such applications, one from network security and the other from bioinformatics, both of which are significantly faster than their state-of-art counterparts. Our research has also widened the scope of the applications which can be accelerated through this processor by finding ways to quickly program any generic graph into it and then search for hard to find features like maximal-cliques and Hamiltonian paths. These applications and algorithms have yielded valuable design-inputs for next generation of the chip which is currently in design phase. We hope that this work paves the way to the early adoption of this upcoming architecture and to efficient solution of some of the currently computationally challenging problems.
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Elder, Ian F. "Diode-pumped two micron solid-state lasers." Thesis, University of Strathclyde, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.284812.
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Gharehbaghi, Ali. "Precipitation Study in a High Temperature Austenitic Stainless Steel using Low Voltage Energy Dispersive X-ray Spectroscopy." Thesis, KTH, Materialens processteknologi, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-103492.
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Precipitation of second phase particles is a key factor dominating the mechanical properties of high temperature alloys. In order to control and optimize the precipitation effect it is of great importance to study the role of alloying elements in the formation and stability of precipitates. As a favored family of corrosion and creep resistant austenitic stainless steels the 20Cr-25Ni alloy was modified by addition of copper, molybdenum, nitrogen, niobium and vanadium. A set of alloys with similar matrix but varying contents of niobium, vanadium and nitrogen were prepared. Sample preparation process included melting, hot forging, solution annealing and finally aging for 500 h at 700, 800 and 850 ºC.Light optical and scanning electron microscopy revealed micron-scale precipitates on grain and twin boundaries as well as sub-micron intragranular precipitates in all samples. Characterization of precipitates was carried out by means of energy dispersive X-ray spectroscopy (EDS). Among micron-scale precipitates M23C6 carbide was the dominant phase at 700 ºC aging temperature; whereas silicon-rich eta phase (M5SiC) was the main precipitate in samples aged at 800 and 850 ºC. A few sigma phase particles were found in one of the niobium containing samples aged at 700 and 800 ºC. Sub-micron intragranular precipitates were analyzed using low voltage EDS. The spatial resolution of EDS microanalysis at 5 kV accelerating voltage was estimated as almost 100 nm which was at least eight times better than that using the ordinary 20 kV voltage. Also, low voltage EDS revealed the presence of light elements (carbon, nitrogen and boron) in the composition of sub-micron particles thanks to the less matrix effect in absorption of low energy X-rays of light elements. In samples aged at 700 ºC niobium-rich and vanadium-rich carbonitrides were found as the dominant precipitates; whereas they contained much less carbon in samples aged at 800 ºC and mostly became carbon-free nitrides with well-defined cuboidal shapes at 850 ºC aging temperature. This showed that niobium/vanadium-rich nitride phases are stable precipitates at aging temperatures above 700 ºC.The drawbacks of low voltage EDS were indicated as high detection limit (no detection of low- content elements), poor accuracy of quantitative analysis and high sensitivity to surface contamination. Some possible ways to improve the accuracy of low voltage EDS, e.g. longer acquisition time were examined and some other suggestions are proposed for future works.
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Collin, Frederic. "Fragments of microcin B17 as a source of new topoisomerase inhibitors." Thesis, University of East Anglia, 2010. https://ueaeprints.uea.ac.uk/35074/.
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Parks, William Matthew. "The interaction between DNA gyrase and the peptide antibiotic Microcin B17." Thesis, University of East Anglia, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.426951.
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Oinuma, Ryoji. "Fundamental study of evaporation model in micron pore." Texas A&M University, 2004. http://hdl.handle.net/1969.1/1239.
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As the demand for high performance small electronic devices has increased, heat removal
from these devices for space use is approaching critical limits. A heat pipe is a promising
device to enhance the heat removal performance due to the phase change phenomena for
space thermal management system. Even though a heat pipe has a big potential to remove
the thermal energy from a high heat flux source, the heat removal performance of heat
pipes cannot be predicted well since the first principle of evaporation has not been
established. The purpose of this study is to establish a method to apply the evaporation
model based on the statistical rate theory for engineering application including
vapor-liquid-structure intermolecular effect. The evaporation model is applied to the heat
pipe performance analysis through a pressure balance and an energy balance in the loop
heat pipe.
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Mountford, Lorna Catherine. "High intensity laser interactions with sub-micron droplets." Thesis, Imperial College London, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.369219.
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Murray, J. A. H. "Molecular analysis of the yeast two micron plasmid." Thesis, University College London (University of London), 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.378050.
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Tupper, Malinda M. 1974. "Fabrication and assembly of micron-scale ceramic components." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/17675.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2004."February 2004."
Includes bibliographical references (p. 146-152).
The micron-scale manufacturing industry has grown to hundreds of billions of dollars since the advent of the transistor in 1947. Increasing demands for integration of surface mount components, greater use of portable electronic devices, and miniaturized medical diagnostic devices have given rise to the need for methods of fabricating and assembling micron-scale discrete components. Development of reliable non-contact assembly methods requires thorough understanding of electro-mechanics, surface adhesion, and gravitational forces acting on micron- scale objects. The impact of such a study will spread beyond microelectronics, and will also have broad significance in the development of micro-electromechanical systems (MEMS) for diverse applications such as biological assays, drug delivery devices, and tools for high throughput combinatorial materials development. This thesis will discuss methods for and challenges in fabrication, manipulation, and assembly of discrete micron-scale objects. The impact of these issues will be illustrated for the development of a micro-dispensing system used to manipulate microgram quantities of dry granular substances for combinatorial materials development. This method provides a model system to explore the forces on micron-scale objects, and is important in its own right as it will introduce a new range of materials that may benefit from combinatorial development. The applicability of traditional methods for computing dielectrophoretic forces on micron scale objects in the presence of spatially non-uniform electric fields will be discussed for the case of closely-spaced, interacting spheres.
(cont.) A dipole approximation model will be presented to quantitatively illustrate the limitations of existing techniques for calculating these forces, and to aid in explaining the observed motion of multiple interacting particles.
by Malinda M. Tupper.
Ph.D.
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Oey, James Boe-Kian 1980. "Cell-based array for deep sub-micron technologies." Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/18030.
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Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2003.Includes bibliographical references (p. 161).
In this thesis I explore transistor topologies for high density cell-based arrays that allows for dense computation blocks, small memory cells, and strong signal drivers. This involves simulating different circuit types with HSPICE to determine ideal transistor sizes. Using Magic and the results of the HSPICE simulations, I explore transistor topologies with different ratios of nFets to pFets. An analysis on the technology shows important characteristics for digital systems and how they relate to the explored transistor topologies.
by James Boe-Kian Oey.
M.Eng.
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Gervasio, Michelle Rose. "Sub-micron Patterning of ZnO-PMMA Hybrid Films." Diss., Virginia Tech, 2019. http://hdl.handle.net/10919/86887.
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Sub-micron patterning is fundamental to the fabrication of numerous devices Traditional commercial manufacturing methods either lack the resolution needed to attain the appropriate size or are prohibitively expensive due to low throughput or the necessity of expensive equipment. Imprint lithography is a rapid, inexpensive alternative to making sub-micron features that can be tailored to work with a variety of materials. Imprint lithography, while traditionally used with pure polymers has been tailored to be used with nanoparticle-polymer hybrid films. This work has achieved high-fidelity pattern transfer onto polymer-nanoparticle hybrid films with feature sizes as small as 250 nm.
The polymer-nanoparticle hybrid was fabricated by creating a liquid suspension of functionalized ZnO nanoparticles and poly(methyl methacrylate) (PMMA) in a solvent. The ZnO particles were functionalized by adding nonanoic acid in order to facilitate the dispersion of the particles in a non-polar solvent. This suspension was spread onto substrate, imprinted with a patterned stamp, allowed to dry, and was demolded. The final result was features ranging from 250 nm to 1 μm in size with good fidelity as determined by the accuracy of the feature replication and the surface roughness of the overall sample. The effect of the ZnO content as well as the method of combining the suspension components on the feature fidelity was studied. In general, it was found that feature fidelity is acceptable up to a dry-film composition of 15 vol% ZnO and that feature sizes above 500 nm were more tolerant of higher solids loading.
The same imprint lithography method was also used to pattern a polymer-derived SiOC glass. The SiOC was shown to be have interesting shrinkage properties where the feature-level linear shrinkage was up to 5% more than that of the bulk. The features were
shown to be stable during pyrolysis up to 1000oC and stable at operating temperatures up to 1000oC.
A constant number Monte Carlo simulation was used to describe the suspension behavior to confirm the empirical results from the physical experiments. The effects of Van der Waals forces, steric stabilization, depletion flocculation, as well as the physical impediment of entangled polymer chains were considered. A similar agglomeration behavior was shown in the simulations compared to the physical experiments.
This thesis shows that polymer-nanoparticle hybrid films are a compatible material for imprint lithography using appropriate suspension parameters. This is very important for a variety of applications and devices. Using imprint lithography to make these devices makes them cheaper and more accessible to the commercial market and can make a large number of theoretical devices a reality.Ph. D.
Sub-micron patterning is an integral part of making many modern technologies such as memory storage devices or integrated circuits. As this technology becomes smaller and smaller, the limiting factor for making these devices has become the ability to manufacture effectively at the appropriate scale. Traditional commercial manufacturing methods lack the resolution needed to attain small enough features. Manufacturing methods that can make small enough features are often either extremely expensive or offer incomplete control of the feature morphology. Imprint lithography is a high-throughput, inexpensive alternative to making sub-micron features that can be tailored to work with a variety of materials. Imprint lithography is simple process in which a patterned stamp is pressed into a softened film of material in order to transfer the pattern of the stamp onto that material. Traditionally, imprint lithography works best with polymers and researchers have struggled to pattern nanoparticle-based materials. This work has achieved high-fidelity pattern transfer onto polymer-nanoparticle hybrid films with feature sizes on the same order as the polymer films found reported in literature. The polymer-nanoparticle hybrid was realized by creating a liquid suspension of functionalized ZnO nanoparticles and poly(methyl methacrylate) (PMMA) in a solvent. The ZnO particles were functionalized by adding nonanoic acid, allowing the normally polar particles to disperse in the non-polar solvent needed to dissolve the PMMA. This suspension was spread onto a glass substrate, imprinted with a patterned stamp, allowed to dry, and was demolded. The final result was the successful transfer of features ranging from 250 nm to 1 μm in size with good fidelity. The effect of the ZnO content as well as the method of combining the suspension components on the feature fidelity was studied. To help prove the broad applicability of this imprint method, it was adapted for use with polymer-derived ceramics. Additionally, a computer simulation was developed to help understand the behavior of the nanoparticle-polymer suspension during the imprint process.
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Malik, Asif. "OPISA optoelectronics packaging interfaces for sub-micron alignment." Thesis, University of Greenwich, 2014. http://gala.gre.ac.uk/18142/.
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For optoelectronic devices submicron precision is required to optimally couple the laser source with the optical fibre. Laser welding is used because of its inherent attributes of accuracy, strength, cleanliness and minimised heat affected zone and structural changes. Due to the rapid solidification of the welded parts post welding residual stresses occur which can lead to a post weld shift between the aligned components and can significantly reduce the light coupling efficiency. Submicron misalignment induced due to the welding process can result in significant power loss. This is a serious and common issue in the manufacture of optoelectronic components and affects production rates. The aim of this work is the development of a methodology that can estimate the residual stresses in the weld piece and to optimise the process by locating the optimal site for micro laser welding. The aim establishes the research question which was addressed by nine objectives. The first eight objectives are elements that comprise the Optoelectronic Packaging Interfaces for Sub-Micron Alignment (OPISA) project. The final objective is the dissemination of this work. Finite element models were developed and used with design of experiments (DoE) statistical technique. This was used to investigate how the key process parameters influence the resultant stress in the optical fibre and to develop a predictive surrogate model. The surrogate model was used with Monte Carlo simulations to determine the fibre stress variation when uncertainty and variation of the design variables are accounted for. The Monte Carlo simulations predicted fibre stress response values which were used to understand how the uncertainties of the input design variables propagate into uncertainty and variation of fibre stress. The surrogate model was used in a sensitivity and risk analysis. The capability analysis of the welding process was also investigated. The original finding of this work is the development of a methodology that fulfils the aim. The work successfully demonstrated that the current industry weld spot location generate 180MPa of post weld stress in the optical fibre. Using the OPISA methodology the optimal weld locations generate 57.6MPa of post weld stress in the optical fibre.
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Le, Ru Eric C. "Propriétés optiques des boîtes quantiques d'InAs pour les applications à grande longueur d'onde." Palaiseau, Ecole polytechnique, 2002. http://www.theses.fr/2002EPXX0035.
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Lemieux, Jacob. "Genomic Analysis of Evolution in Plasmodium falciparum and Babesia microti." Thesis, Harvard University, 2015. http://nrs.harvard.edu/urn-3:HUL.InstRepos:15821587.
Full textAbstract:
Parasitic protozoan infections of the red blood cell are among the most widespread and devastating pathogens of vertebrates. In humans, two genera of pathogens cause disease: the Plasmodia, which cause malaria, and the Babesia, which cause babesiosis. In this thesis, we apply the tools of whole genome sequencing and evolutionary genetics to study factors contributing to the spread of these pathogens: in P. falciparum, the acquisition of multiple drug resistance, and in B. microti the development of azithromycin resistance and the population genetics of emergence.
In the first part of this work, we test whether an accelerated mutation rate predisposes to acquisition of drug resistance in P. falciparum. Epidemiologically, resistance tends to begin along the Thai-Cambodian border, and from there spreads to other parts of the world. Environmental conditions such as inadequate drug dosing likely facilitate drug resistance, but molecular evidence also suggests that parasites from the Thai-Cambodian border may harbor genetic traits that let them develop resistance to novel antimalarials at an elevated rate. Low-dose drug pressure has also been proposed to be mutagenic, since several antimalarial agents have known DNA binding properties and have been shown to impair DNA damage repair pathways in P. falciparum. To test these hypotheses, we directly assayed substitution rates in a parasite line from the Thai-Cambodian border and a South American isolate, with and without chloroquine pressure. Sampling parasite DNA over a total of 760 generations (~4.2 years), we identified 17 mutations, producing an estimate of the substitution rate at 1.065x10^9 substitutions per site, per generation. We find that chloroquine pressure does not alter the mutation rate. We further find that substitutions accrued at an approximately 3-fold rate in the lines from Southeast Asia, a result which trended toward but did not reach statistical significance (p = 0.056). We argue that this is insucient by itself to account for the rapidly increased rate at which ARMD parasites acquire drug resistance. By sequencing intermediate timepoints, we also characterize the dynamics of allele substitution in vitro.
In the second part of this thesis, we characterize Babesia microti by sequencing clinical isolates and enzootic strains. Since the first case in 1969 [36], human babesiosis due B. microti has emerged as important infection in the Northeast USA [84]. In order to characterize natural selection, recent evolutionary history, and the genetic architec ture of Babesia microti populations, we created a map of genetic diversity from clinical strains. We describe this map, and show that B. microti isolates from the Northeast USA possess a paucity of nucleotide diversity, consistent with very recent common ancestry of circulating strains. We describe how B. microti genomes display a predominance of rare alleles and a number of segregating sites in excess of pairwise nucleotide diversity, suggestive of a recent population expansion. Finally, we identify RPL4 as a candidate gene for azithromycin resistance based on a non-synonymous substitution that occurs in a highly conserved arginine in the azithromycin binding region of the L4 component of the 50S ribosomal subunit in a patient with azithromycin failure.
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Ibrahim, Mohamed Ali. "Mycobacterium microti and vole tuberculosis : improved diagnostics and molecular epidemiology." Thesis, University of Liverpool, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.511057.
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Brar, Tenjinder. "NOVEL WAYS OF SYNTHESIZING ZEOLITE A." University of Cincinnati / OhioLINK, 2000. http://rave.ohiolink.edu/etdc/view?acc_num=ucin973702236.
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Depoix, Delphine. "Analyse chromosomique du génome de Babesia (B. Canis, B. Divergens, B. Microti)." Montpellier 1, 2003. http://www.theses.fr/2003MON13506.
Full textAbstract:
Le génome des Babesia, hémoprotozoaires parasites du phylum des Apicomplexa, étant largement méconnu, nous avons effectué une approche chromosomique par PFGE, suivie d'expériences d'hybridation moléculaire du génome de l'espèce canine B. Canis mondialement répandue, de l'espèce bovine européenne B. Divergens et de l'espèce murine B. Microti (Theileria microti), principal agent de la babéiose humaine aux U. S. A. . L'utilisation d'une sonde télomérique dérivée du génome de Plasmodium berghei et de sondes spécifiques du génome des espèces étudiées, a permis de déterminer la taille du génome, le nombre de chromosomes et d'analyser le polymorphisme caryotypique de chacune d'elles. Ainsi, l'étude du génome de B. Divergens, à travers 7 isolats des deux sous-espèces canines les plus pathogènes i. E. B. Canis canis (Europe) et B. Canis rossi (Afrique du sud), a mis en évidence 5 chromosomes pour un génome estimé à 14,5 Mpb et 16 Mpb, respectivement. Toutefois, l'analyse comparée de l'organisation télomérique possible et du contenu génique de ces deux sous-espèces a montré qu'il existait autant de différences entre celles-ci qu'entre chacune d'elles et l'espèce B. Divergens. Le génome de B. Microti estimé à 6,5 Mpb pour 4 chromosomes, apparaît quant à lui comme le plus petit génome de Babesia décrit. Enfin, cette analyse chromosomique a permis de démontrer que les gènes Bd37 sont localisés sur le chromosome 2 de B. Divergens, tandis que ceux de la famille Bc3. 1 seraient localisés sur les 5 chromosomes de B. Canis. L'analyse du polymorphisme des deux membres de la famille Bc3. 1 indique un polymorphisme important entre les extrémités 3' des deux copies et une grande conservation de ces deux copies entre isolats géographiquement distants.
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Marcheselli, Marco. "Modelli in vitro per lo studio dell'ecologia microbica del sistema gastro intestinale." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2018. http://amslaurea.unibo.it/17005/.
Full textAbstract:
Il crescente interesse della comunità scientifica sul microbiota intestinale e sul ruolo che svolge nell’interazione con l’ospite ha accelerato l’evoluzione di sistemi alternativi allo studio in vivo su animali. Questi sistemi riguardano fermentatori in vitro capaci di simulare, a seconda del modello, aree distinte del tratto digestivo.
I modelli in vitro sono un potente strumento necessario per comprendere l'impatto della dieta sul microbiota intestinale, in particolare, le colture continue a multi-stadi consentono di eseguire studi a lungo termine, per valutare eventuali perturbazioni del microbiota in condizioni di stato stazionario. Le recenti modifiche come l’immobilizzazione del microbiota fecale, il movimento peristaltico, l’aggiunta di mucina e la capacità di eseguire trattamenti in parallelo hanno migliorato la capacità di questi strumenti di avvicinarci sempre più alla realtà umana in vivo. Questi strumenti, partendo da culture pure, miste o da campioni fecali, ci aiutano nella comprensione dei fenomeni di interazione che avvengano nel tratto digestivo del nostro organismo. In questa tesi discuto i modelli più utilizzati, associati ad applicazioni che li vedono coinvolti nella comprensione del ruolo dei polifenoli, prebiotici e nell’uso di farmaci.
L’introduzione iniziale ha l’obbiettivo di dare un quadro generale sulla composizione del microbiota nelle principali aree dell’apparato gastrointestinale.
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Falzetti, Francesco. "Influenza di nanoparticelle di magnetite sull’elettrosintesi microbica di substrati organici da CO2." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2019.
Find full textAbstract:
Dopo una premessa preliminare sulla bioraffineria, si passa alla descrizione in dettaglio della carboxylate platform e dei suoi possibili sviluppi, fra cui vi è quello dello studio di sistemi bioelettrochimici, nello specifico elettrosintetici catodici. A questo punto si passa per una breve descrizione del metabolismo di un fango da digestione anaerobica, prima di arrivare all'obiettivo della tesi. L'obiettivo è udi fare una valutazione dell'influenza di nanoparticelle di magnetite sull'attività di alcuni sistemi bioelettrosintetici microbici (inoculati con fango da digestione anaerobica): un sistema batch a celle e uno con configurazione reattoristica in continuo, passando per un sistema di controllo di verifica abiotico. L'attenzione è focalizzata sulla cinetica e sulla produttività di questi sistemi in termini di prodotti di sintesi utili (VFA e metano), a partire da anidride carbonica come unica fonte di carbonio e un potenziale esterno, fra i comparti catodico e anodico, imposto e fisso come fonte di potere riducente per l'inoculo biotico catodico
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Tcheou, Eric. "Flow boiling of refrigerant-oil mixtures in horizontal, plain and microfin tubes." Thesis, Heriot-Watt University, 1996. http://hdl.handle.net/10399/632.
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Elizondo, Martinez Jorge. "Microrid operation strategy for improved recovery and inertial response after large disturbances." Thesis, Massachusetts Institute of Technology, 2016. http://hdl.handle.net/1721.1/105659.
Full textAbstract:
Thesis: Ph. D., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2016.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 177-183).
The electric grid is one of the major achievements of human kind. In the last hundred years it has grown from small clusters of generation and loads, into large networks containing millions of elements and spanning entire continents. Recently, the increasing deployment of distributed generators (DGs) has triggered a grid transformation from a rigid to a flexible and de-centralized structure. Microgrids are an essential element in this transformation because by grouping DGs and loads into controllable units, they can provide a coordinated response to maximize their impact on the grid. Microgrids are inherently different from the larger grid. This thesis shows how by challenging the paradigm of constant frequency and voltage operation, a new strategy can be implemented to achieve an improved response after large disturbances without compromising safety. Large disturbances are commonly encountered in the grid and disrupt the power balance that is required for a reliable operation. If the imbalance is large enough and the proper actions are not taken, then a blackout will occur, affecting millions of people and creating a severe economic impact. To demonstrate the advantages of the proposed operation strategy, two large disturbances are studied: a fault in the distribution network that creates a reactive power imbalance due to induction motor stalling, and a sudden change in generation or consumption that leads to a real power imbalance. In the first part, a framework is created to study fault events and then used to describe a fault recovery strategy that expands the stability region of the system. In the second part, the proposed operation strategy is presented as a new control technique that allows energy to be extracted from the induction motors in the system to achieve an inertial response and provide frequency regulation. All the results are validated using a microgrid experimental set-up that was built as part of this thesis.
by Jorge Elizondo Martinez.
Ph. D.
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James, Allison Melissa. "Babesia microti cysteine protease-1 as a target for vaccine development." Thesis, Texas A&M University, 2005. http://hdl.handle.net/1969.1/4192.
Full textAbstract:
Babesia species have a worldwide distribution, affecting a wide range of mammalian
hosts. The major route of transmission is inoculation by an infected Ixodid tick. Babesia
species of major economic concern are those that cause bovine and equine babesiosis.
Historically, bovine Babesia species, Babesia bovis and Babesia bigemina caused
significant economic losses in the United States in the 1860âÂÂs, as thousands of cattle
died. Also, outbreaks of equine babesiosis, caused by Babesia equi or Babesia caballi,
have occurred in the United States resulting in the death of some horses and millions of
dollars in losses. A constant risk of reinfection with bovine and equine Babesia species
exists, as stray and smuggled animals from Mexico, where bovine babesiosis is endemic,
may carry infected ticks as they cross the border, and, thousands of horses from B. equiand
B. caballi-endemic regions are imported through Florida every year.
Vaccines have been developed for a number of Babesia species, none of which result
in sterile immunity. The live attenuated vaccine is the most commonly used vaccine
against Babesia species. However, the basis for the vaccine is to maintain a carrier state in order to prevent disease. Other vaccine designs have been developed to invoke
protection without a carrier state but have been unsuccessful.
It has been shown that the cysteine protease is important in the life cycle of a number
of parasitic organisms, making it a good target for vaccine development. The vaccine
design for this study incorporated the cysteine protease of Babesia microti. Babesia
microti naturally infects Peromyscus leucopus (white-footed mouse) and is the major
cause of human babesiosis in the United States. Using B. microti in the vaccine design
allowed for the use of a mouse model to determine whether the cysteine protease of
other economically important Babesia species may make a good vaccine target. The
vaccine design incorporated a prime-boost strategy, priming with DNA encoding the
cysteine protease and boosting two times with either DNA encoding the cysteine
protease or cysteine protease peptide, followed by parasite challenge. Analysis of daily
percent parasitemias, packed cell volume, and seroconversion of all groups revealed that
a protective immune response against B. microti was not elicited by this vaccine strategy.