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Dalton, Timothy Joseph. "Pattern dependencies in the plasma etching of polysilicon." Thesis, Massachusetts Institute of Technology, 1994. http://hdl.handle.net/1721.1/11655.
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Brown, Caroline E. "Effects of feeding pattern on plasma ghrelin concentrations in pigs." Go to full text online (pdf), 2005. http://www.lib.ncsu.edu/theses/available/etd-06022005-171635/unrestricted/etd.pdf.
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Zhu, Guo-Qiang. "Modeling of plasma dynamics and pattern formation during high pressure microwave breakdown in air." Phd thesis, Université Paul Sabatier - Toulouse III, 2012. http://tel.archives-ouvertes.fr/tel-00668934.
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Dans cette thèse, un modèle de la dynamique du plasma après un claquage microonde dans l'air à pression atmosphérique a été développé. Ce modèle a permis d'expliquer pour la première fois la formation et la dynamique de structures filamentaires auto-organisées lors du claquage microonde. Le claquage microonde dans l'air à pression atmosphérique a été récemment observé au MIT dans des expériences mettant en oeuvre une source microonde de puissance et des caméras rapides. Les mesures montrent que, lors du claquage, un ensemble structuré de filaments de plasma se forme et se dirige vers la source à une vitesse de plusieurs km/s. Les mécanismes de formation et de propagation de ces structures auto-organisées de plasma ne sont pas bien compris et l'objectif de cette thèse a été de mettre en évidence et de modéliser les phénomènes physiques de base qui en sont responsables. Dans le but de décrire la dynamique du plasma après claquage, les équations de Maxwell ont été couplées à un modèle simple de plasma et résolues numériquement. Le modèle de plasma suppose la quasineutralité et décrit l'évolution de la densité de plasma sous l'effet de la diffusion, de l'ionisation, de l'attachement et de la recombinaison électron-ion. L'ionisation et l'attachement sont supposés dépendre du champ électrique effectif local. La vitesse moyenne électronique est déduite d'une équation de transport de quantité de mouvement simplifiée. La diffusion des particules chargées est ambipolaire au sein du plasma mais devient libre dans le front où la densité chute à zéro. Une expression heuristique de la transition entre diffusion ambipolaire dans le corps du plasma et diffusion libre sur les bords a été établie et validée à l'aide d'un modèle mono-dimensionnel de type dérive-diffusion-Poisson que nous avons développé et dans lequel on ne suppose pas la quasineutralité du plasma. Le modèle plasma-Maxwell quasineutre a ensuite été utilisé pour étudier la dynamique du plasma après claquage dans les conditions des expériences du MIT. Les résultats numériques montrent la formation de structures filamentaires auto-organisées de plasma en excellent accord qualitatif avec les observations expérimentales. Ces structures auto-organisées sont liées aux structures du champ électrique diffracté par le plasma. De nouveaux filaments se forment de façon continue dans le front du plasma par des phénomènes de diffusion-ionisation. Le modèle montre que la formation d'un réseau de filaments de plasma auto-organisé est dû à l'apparition des maxima de champ électrique de l'onde stationnaire formée dans le front du plasma. Dans la dernière partie de la thèse, la formation d'un filament de plasma isolé (ou streamer microonde) au maximum de champ formé à l'intersection de deux faisceaux microondes est analysée à l'aide du modèle. Le streamer microonde s'allonge parallèlement à la direction du champ en raison du renforcement du champ à ses pôles (phénomène de polarisation). L'intensité du champ aux extrémités du filament est modulée dans le temps en raison de phénomènes de résonance pour des longueurs de filaments voisines de multiples de la demi longueur d'onde.
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Zhu, Guo-Qiang. "Modeling of plasma dynamics and pattern formation during high pressure microwave breakdown in air." Phd thesis, Toulouse 3, 2012. http://thesesups.ups-tlse.fr/1563/.
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Dans cette thèse, un modèle de la dynamique du plasma après un claquage microonde dans l'air à pression atmosphérique a été développé. Ce modèle a permis d'expliquer pour la première fois la formation et la dynamique de structures filamentaires auto-organisées lors du claquage microonde. Le claquage microonde dans l'air à pression atmosphérique a été récemment observé au MIT dans des expériences mettant en œuvre une source microonde de puissance et des caméras rapides. Les mesures montrent que, lors du claquage, un ensemble structuré de filaments de plasma se forme et se dirige vers la source à une vitesse de plusieurs km/s. Les mécanismes de formation et de propagation de ces structures auto-organisées de plasma ne sont pas bien compris et l'objectif de cette thèse a été de mettre en évidence et de modéliser les phénomènes physiques de base qui en sont responsables. Dans le but de décrire la dynamique du plasma après claquage, les équations de Maxwell ont été couplées à un modèle simple de plasma et résolues numériquement. Le modèle de plasma suppose la quasineutralité et décrit l'évolution de la densité de plasma sous l'effet de la diffusion, de l'ionisation, de l'attachement et de la recombinaison électron-ion. L'ionisation et l'attachement sont supposés dépendre du champ électrique effectif local. La vitesse moyenne électronique est déduite d'une équation de transport de quantité de mouvement simplifiée. La diffusion des particules chargées est ambipolaire au sein du plasma mais devient libre dans le front où la densité chute à zéro. Une expression heuristique de la transition entre diffusion ambipolaire dans le corps du plasma et diffusion libre sur les bords a été établie et validée à l'aide d'un modèle mono-dimensionnel de type dérive-diffusion-Poisson que nous avons développé et dans lequel on ne suppose pas la quasineutralité du plasma. Le modèle plasma-Maxwell quasineutre a ensuite été utilisé pour étudier la dynamique du plasma après claquage dans les conditions des expériences du MIT. Les résultats numériques montrent la formation de structures filamentaires auto-organisées de plasma en excellent accord qualitatif avec les observations expérimentales. Ces structures auto-organisées sont liées aux structures du champ électrique diffracté par le plasma. De nouveaux filaments se forment de façon continue dans le front du plasma par des phénomènes de diffusion-ionisation. Le modèle montre que la formation d'un réseau de filaments de plasma auto-organisé est dû à l'apparition des maxima de champ électrique de l'onde stationnaire formée dans le front du plasma. Dans la dernière partie de la thèse, la formation d'un filament de plasma isolé (ou streamer microonde) au maximum de champ formé à l'intersection de deux faisceaux microondes est analysée à l'aide du modèle. Le streamer microonde s'allonge parallèlement à la direction du champ en raison du renforcement du champ à ses pôles (phénomène de polarisation). L'intensité du champ aux extrémités du filament est modulée dans le temps en raison de phénomènes de résonance pour des longueurs de filaments voisines de multiples de la demi longueur d'onde<br>In this thesis, a model for the plasma dynamics after microwave breakdown at atmospheric pressure in air has been developed. The model has been able to explain for the first time the formation and dynamics of self-organized structures during microwave breakdown. Microwave breakdown in air at atmospheric pressure has been recently observed at MIT with high power microwave sources and fast CCD cameras. The measurements show that a self-organized multi-streamer array forms and propagates towards the incident microwave source with a high velocity (several km/s) during the discharge. The detailed dynamics of the self-organized streamer structures during microwave breakdown is still not well understood and the objective of this thesis was to clarify the physics of the plasma dynamics and self-organization during and after microwave breakdown. In order to study the plasma dynamics in microwave breakdown, Maxwell's equations have been coupled to a simple plasma model and solved numerically. The plasma model assumes quasineutrality and describes the evolution of the plasma due to diffusion, ionization, attachment and recombination. Ionization and attachment are supposed to depend on the local effective field. The electron mean velocity is obtained from a simplified momentum equation. The diffusion coefficient must be ambipolar in the plasma bulk but should be equal to the free electron diffusion on the edge of the plasma since the plasma density decays to zero in the front. A heuristic expression of the transition from ambipolar diffusion in the bulk plasma to free diffusion at the edges has been derived and validated with a non-neutral one-dimensional (1D) model based on drift-diffusion and Poisson's equations. The 1D and 2D plasma-Maxwell models have been used to study the plasma dynamics after breakdown in the conditions of the MIT experiments. The numerical results show the formation of self-organized structures or patterns that are in excellent qualitative agreement with the MIT measurements. The formation of the self-organized dynamical pattern can be attributed to the scattering of the microwave field by the plasma. New filaments continuously form in the plasma front due to diffusion-ionization mechanisms. The model shows that the formation of the filamentary plasma array is associated with the standing wave pattern formed by the microwave field scattered by the plasma. In the last part of the thesis we analyze the formation of a single, isolated microwave filament or streamer at the antinode of a standing wave formed at the intersection of two microwave beams. The microwave streamer stretches in a direction parallel to the electric field because of polarization effects. The model results show that the field is strongly enhanced at the tips of the microwave filament and that the field intensity is modulated in time as the streamer length increases. This modulation is associated with resonant effect when the filament length reached values that are close to multiples of the half wavelength
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Abrokwah, Kwaku O. "Characterization and modeling of plasma etch pattern dependencies in integrated circuits." Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/37054.
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Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2006.<br>Leaf 108 blank.<br>Includes bibliographical references (leaves 106-107).<br>A quantitative model capturing pattern dependent effects in plasma etching of integrated circuits (ICs) is presented. Plasma etching is a key process for pattern formation in IC manufacturing. Unfortunately, pattern dependent non-uniformities arise in plasma etching due to microloading and RIE lag. This thesis contributes a semi-empirical methodology for capturing and modeling microloading, RIE lag, and related pattern dependent effects. We apply this methodology to the study of interconnect trench etching, and show that an integrated model is able to predict both pattern density and feature size dependent non-uniformities in trench depth. Previous studies of variation in plasma etching have characterized microloading (due to pattern density), and RIE lag (aspect ratio dependent etching or ARDE) as distinct causes of etch non-uniformity for individual features. In contrast to these previous works, we present here a characterization and computational methodology for predicting IC etch variation on a chip scale that integrates both layout pattern density and feature scale or ARDE dependencies. The proposed integrated model performs well in predicting etch variation as compared to a pattern density only or feature scale only model.<br>by Kwaku O. Abrokwah.<br>M.Eng.
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Farahanchi, Ali. "Characterization and modeling of pattern dependencies and time evolution in plasma etching." Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/55265.
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Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, June 2009.<br>"May 2008." Cataloged from PDF version of thesis.<br>Includes bibliographical references (p. 43).<br>A quantitative model capturing pattern dependent effects and time evolution of the etch rate in Deep Reactive Ion Etching (DRIE) is presented. DRIE is a key process for pattern formation in semiconductor fabrication. Non-uniformities are caused due to microloading and aspect ratio dependencies. The etch rate varies over time and lateral etch consumes some of the etching species. This thesis contributes a physical analysis for capturing and modeling microloading, aspect ratio dependencies, effects of lateral etch and time evolution of the etch rate. This methodology is applied to the study of etching variation on silicon wafers; the integrated model is able to predict pattern density and feature size dependent non-uniformities in trench depth and time evolution of the etch rate. Previous studies of variation in plasma etching have characterized microloading and aspect ratio dependent etching (ARDE) as distinct constant causes for etch non-uniformity. In contrast to these previous works, we present here a time-based methodology for vertical and lateral etch.<br>by Ali Farahanchi.<br>M.Eng.
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Dahlan, Winai. "Intravenous infusion of triacylglycerol-phospholipid complexes in man: effects on fatty acid pattern of plasma and on erythrocyte membrane lipid composition." Doctoral thesis, Universite Libre de Bruxelles, 1989. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/213206.
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Pedrielli, Andrea. "Integrazione tecnologica di grafene cresciuto per deposizione chimica da fase vapore per applicazioni termiche e termoelettriche." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amslaurea.unibo.it/7613/.
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L’obiettivo del lavoro di tesi è quello di studiare l’integrazione del grafene con i processi tecnologici propri della tecnologia del silicio, per la realizzazione di dispositivi innovativi per la misura delle proprietà termiche e termoelettriche del grafene che sono tra le meno studiate ad oggi.
L’attività sperimentale svolta, ha riguardato l’intero processo di produzione, processing ed integrazione tecnologica del grafene. Da una parte è stato messo a punto un processo ottimizzato, partendo da una approfondita ricerca bibliografica, per il trasferimento delle membrane dai substrati di crescita, in rame, a quelli di destinazione, SiO2 e Si3N4, mantenendo la completa compatibilità con i processi della microelettronica del silicio in particolare per quanto riguarda l’eliminazione dei residui metallici dalla sintesi. Dall’altra è stata sviluppata una procedura di patterning micrometrico del grafene, affidabile e riproducibile, e, soprattutto, compatibile con la microelettronica del silicio.
Le membrane, cresciute tramite deposizione da fase vapore (Chemical Vapor Deposition), sono state caratterizzate tramite la microscopia elettronica, a scansione e in trasmissione, la microscopia ottica, spettroscopia Raman e microscopia a forza atomica, tecniche che sono state utilizzate per caratterizzare i campioni durante l'intero processo di patterning. Il processo di etching del grafene in ossigeno, realizzato con il plasma cleaner, strumento che nasce per la pulizia di campioni per microscopia elettronica, è stato messo a punto il attraverso una estesa attività di test sia dei parametri di funzionamento dello strumento che del fotoresist da utilizzare. La procedura di patterning micrometrico vera e propria, ha comportato di affrontare diverse classi di problemi, dalla rimozione del fotoresist con soluzioni diverse (soluzione di sviluppo dedicata e/o acetone) alla rimozione dei residui presenti sulle membrane di grafene anche a valle del patterning stesso. La rimozione dei residui tramite acido cloridrico, insieme ad una procedura di annealing a 400°C in aria per la rimozione dei residui del fotoresist polimerico che erano presenti a valle dell’etching in ossigeno, ha permesso di ottenere un patterning del grafene ben definito su scala micrometrica e una ridottissima presenza di residui. Le procedure ottimizzate di trasferimento e di patterning sono il principale avanzamento rispetto allo stato dell’arte. Le metodiche messe a punto in questo lavoro, consentiranno di integrare il grafene direttamente nel processo di micro-fabbricazione di dispositivi per misure termiche e termoelettriche, per i quali quali sono in realizzazione le maschere di processo che rappresentando la naturale conclusione del lavoro di tesi.
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Ahner, Nicole. "Wetting Optimized Solutions for Plasma Etch Residue Removal for Application in Interconnect Systems of Integrated Circuits." Doctoral thesis, Universitätsbibliothek Chemnitz, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-102773.
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In multi-level Co/low-k based interconnect systems of ultralarge-scale integrated electronic devices the removal of plasma etch residues by common plasma cleaning processes has been shown to alter material properties like k-value and leakage current of the low-k dielectric. Besides the development of less damaging plasma processes their substitution by wet cleaning steps is in the focus of research and development. With further decreasing feature dimensions the development of wet cleaning processes has to include wetting issues like the non-wetting of small features due to the surface energy of the liquid or pattern collapse effects of low-k dielectric trenches due to high capillary forces This work at first focuses on the determination of the surface energetic character of common cleaning solutions for PERR and differently etched or ashed low-k dielectric surfaces by contact angle analysis, to outline which combinations of solid and liquid will be critical regarding their wetting behavior. Besides the determination of the wetting behavior the contact angle analysis turned out to be a fast and sensible analytic tool to understand the surface modifications introduced by different plasma processes and can help to understand the mechanisms of plasma damage of low-k dielectric surfaces. The analysis showed that especially polymerizing plasma etch processes produce a low-energetic low-k dielectric surface with a negligible polar energy contributions, which inhibits their wetting by high energetic water based cleaning solutions, which actually are favored by semiconductor manufacturers. The strategy to overcome these wetting issues followed in the present work is the reduction of the surface energy of the cleaning liquids by the application of surfactants. Several types of surfactants have been applied to the cleaning liquids and the compatibility of the surfactant solutions to BEOL materials like low-k dielectrics, copper and diffusion barriers as well as their dynamic behavior has been studied. The analysis showed that choosing the appropriate rinsing solution after the cleaning process is essential to ensure its compatibility to porous low-k dielectrics. Optical, electrical and structural data indicated that DIW rinse in most of the cases was not able to remove residual surfactant species within the material, while for an IPA rinse most of the residual surfactants have been removed. Considering the data received for compatibility to low-k materials, copper and barriers, the dynamic behavior of the surfactant solutions as well as influences of increased bath temperature and long term stability a general advice about surfactant selection and processing of surfactant aided solutions within BEOL is given<br>In mehrlagigen Kupfer/low-k basierten Metallisierungssystemen hochintegrierter elektronischer Bauelemente kann die Entfernung von Residuen nach der Plasmastrukturierung des Dielektrikums mittels herkömmlicher Plasmareinigungsprozesse zur Schädigung der Isolatorschicht und damit zum Ansteigen der relativen Dielektrizitätszahl sowie der Leckströme führen. Neben der Entwicklung schädigungsarmer Plasmaprozesse stellt der Ersatz dieser Prozesse durch Nassreinigungsschritte zur Ätzresiduenentfernung eine vielversprechende Alternative dar. Mit stetig abnehmenden Strukturabmaßen ist bei der Entwicklung dieser Nassreinigungsprozesse neben der Materialkompatibilität auch das Benetzungsverhalten der Reinigungsflüssigkeit von entscheidender Bedeutung, da die Oberflächenenergie der Reinigungslösung das Eindringen dieser in kleinste Strukturen verhindern und es durch hohe Kapillarkräfte zum Kollaps von Grabenstrukturen im Dielektrikum kommen kann. In der vorliegenden Arbeit wurde zunächst mittels Kontaktwinkelanalyse die Oberflächenenergie verschieden prozessierter low-k Dielektrikaschichten sowie herkömmlicher Lösungen zur Entfernung von Ätzresiduen untersucht, um hinsichtlich ihres Benetzungsverhaltens besonders kritische Materialkombinationen aufzuzeigen. Neben der Bestimmung des Benetzungsverhaltens hat sich die Kontaktwinkelanalyse zur Oberflächenenergieberechnung als schnelle und empfindliche Methode zur Analyse der Auswirkung von Plasmaprozessen auf die Oberfläche von low-k Dielektrika erwiesen. Die Untersuchungen haben gezeigt, dass besonders polymerisierende Plasmaprozesse eine niederenergetische Oberfläche erzeugen, welche von den derzeit in der Halbleiterfertigung bevorzugten hochenergetischen wasserbasierten Reinigungslösungen nur schlecht benetzt wird. Um diesem Effekt entgegenzuwirken wurde in der vorliegenden Arbeit die Senkung der Oberflächenenergie der Reinigungslösungen durch Zugabe von Tensiden untersucht. Es wurden mehrere Tenside unterschiedlichen Typs den Reinigungsflüssigkeiten zugemischt und die Kompatibilität dieser Lösungen mit low-k Dielektrika, Kupferschichten und Diffusionsbarrieren untersucht sowie ihr dynamisches Verhalten analysiert. Dabei hat sich gezeigt, dass die Auswahl der geeigneten Spüllösung nach dem eigentlichen Reinigungsprozess von entscheidender Bedeutung ist. Optische, elektrische sowie strukturelle Daten deuten darauf hin, dass bei Verwendung einer Spülung mit deionisiertem Wasser in den meisten Fällen Tensidrückstände im porösen Dielektrikum verbleiben. Eine Spülung mit Isopropanol war hingegen in der Lage, einen Großteil dieser Tensidrückstände zu entfernen. Unter Einbeziehung der Daten zur Materialkompatibilität und dem dynamischen Verhalten der Tensidlösungen bei Raumtemperatur und erhöhter Badtemperatur sowie ihrer Langzeitstabilität konnte schließlich eine Prozessempfehlung für die Verwendung der benetzungsoptimierten Reinigungslösungen in der BEOL-Prozessierung gefunden werden
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Gagliardi, Riccardo. "Hybrid Palm Oil (Elaeis oleifera×Elaeis guineensis): Effects on the Human Health." Doctoral thesis, Università Politecnica delle Marche, 2016. http://hdl.handle.net/11566/243134.
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L’olio di palma ibrido (OPI) è ottenuto dai frutti della palma da olio ibrida Elaeis oleifera x Elaeis guineensis. L’OPI contiene elevate quantità di tocotrienoli, tocoferoli e polifenoli. Inoltre il suo profilo acidico è principalmente caratterizzato da acidi grassi (AG) monoinsaturi. L’OPI potrebbe quindi rappresentare un equivalente dell’olio di oliva extravergine (OOE), considerato il “gold standard” tra gli oli alimentari per i suoi effetti salutari. Nonostante la sua peculiare composizione, non ci sono ad oggi dati riguardanti gli effetti dell’OPI sulla salute.
Questo progetto di dottorato ha lo scopo di caratterizzare la frazione antiossidante dell’OPI, e di studiare gli effetti di una supplementazione dietetica con OPI sulla salute cardiovascolare dell’uomo, confrontando gli effetti dell’OPI con quelli ottenuti dall’assunzione di OOE.
A tale scopo, è stato caratterizzato il profilo fenolico dell’OPI e determinata la sua capacità antiossidante. Dopo 3 mesi di supplementazione con OPI o con OOE (25 ml/die), in un trial clinico controllato e randomizzato, sono stati studiati gli effetti dei due oli sul contenuto fenolico del plasma e sulla sua capacità antiossidante, sul pattern lipidico del plasma, e sul profilo degli AG e dei fosfolipidi (FL) negli eritrociti dei pazienti ammessi allo studio.
Il consumo dei due oli ha prodotto effetti simili sui parametri considerati. Al termine dello studio, non sono state evidenziate differenze rilevanti tra i parametri dei pazienti appartenenti ai due gruppi (OPI e OOE). A seguito della supplementazione dei due oli, in entrambi i casi, i valori di colesterolo (C) totale e C-LDL nel plasma si riducono significativamente e l’attività antiossidante ed il contenuto fenolico del plasma incrementano. Simultaneamente, il grado di insaturazione della frazione lipidica totale e delle specie molecolari dei FL negli eritrociti è aumentato. Considerato ciò, l’OPI potrebbe essere considerato l’equivalente tropicale del mediterraneo OOE.<br>Hybrid palm oil (HPO) is the crude oil obtained from the fruits of the interspecific oil palm Elaeis oleifera x Elaeis guineensis. It presents a high content in bioactive compounds, such as polyphenols, tocopherols and mainly tocotrienols, with antioxidant effect. Moreover, the HPO fatty acids (FA) profile is mainly characterized by monounsaturated FA. Due to these properties, HPO could represent an equivalent of the Mediterranean extra-virgin olive oil (EVOO), the “gold standard” among the dietary oils for its well-known positive health effects. In spite of its interesting composition, no data about the health effects of the HPO are nowadays available.
This PhD project aimed to fulfil the chemical characterization of the HPO antioxidant compounds content, and to investigate the effects of a HPO daily supplementation on the human cardiovascular health, comparing the effects of the HPO to those provided by the daily intake of EVOO.
The phenolic profile of the HPO was studied and the antioxidant capacity of the oil was determined by means the ORAC and TEAC assays.
After 3 months of oil supplementation (HPO or EVOO, 25 ml/day) in a randomized controlled clinical trial, the effects of the two oils on the plasma total phenolic content, plasma antioxidant capacity, plasma lipid pattern, erythrocytes phospholipids (PL) composition and erythrocyte FA profile of the volunteers patients were studied.
The two oils provided similar effects, with no relevant differences evidenced at the end of the trial among the patients belonging to the HPO and EVOO groups. Significant reductions in plasma total cholesterol and LDL-cholesterol were observed, with an enhancement of the plasma antioxidant capacity and total phenolic content. The erythrocytes lipid composition (PL and FA) of the participants was affected too by both the HPO and EVOO, increasing the unsaturation grade of the erythrocyte FA. As result, HPO could be considered the tropical equivalent of the EVOO.
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Drewelow, Peter [Verfasser], Marcin W. [Akademischer Betreuer] Jakubowski, Suguru [Akademischer Betreuer] Masuzaki, Mario [Akademischer Betreuer] Dähne, Dieter [Akademischer Betreuer] Breitschwerdt, and Robert [Akademischer Betreuer] Wolf. "Investigation of divertor heat flux pattern and their correlation to the edge magnetic field of the plasma confinement experiment LHD / Peter Drewelow. Gutachter: Mario Dähne ; Dieter Breitschwerdt ; Robert Wolf ; Suguru Masuzaki. Betreuer: Marcin W. Jakubowski ; Suguru Masuzaki." Berlin : Technische Universität Berlin, 2013. http://d-nb.info/1067385290/34.
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Mansutti, Giulia. "Analysis and design of innovative antenna systems for telecommunications and health applications." Doctoral thesis, Università degli studi di Padova, 2018. http://hdl.handle.net/11577/3421863.
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In this thesis the study of different innovative antenna systems is presented. The antenna designs that have been analyzed and that are described in this thesis can be divided in three main groups based on their application: phased-array antennas working on surfaces that change shape in time, millimeter-wave antennas for skin cancer diagnosis, and gaseous plasma antennas for satellite communications.
As far as the first topic is concerned, the research activity presented in this thesis focuses on the study of the strengths and limitations of a specific pattern recovery technique: the projection method. This technique has been adopted to retrieve the radiation properties of linear and planar arrays placed on surfaces whose shape changes in time according to different geometrical deformation; moreover, its effectiveness was assessed for both broadside and beam steering arrays, leading to a novel and simpler formulation of this pattern recovery technique for arrays whose beam is tilted towards different directions. The results have been obtained both through full-wave numerical simulations in CST Microwave Studio and through measurements performed in collaboration with the North Dakota State University (NDSU), Fargo, North Dakota, USA.
Regarding skin cancer diagnosis, a novel substrate integrated waveguide probe for early-stage skin cancer detection has been designed as well: this probe is cheap and easy to fabricate and can achieve high accuracy in detecting small early-stage skin cancer, thus providing a tool with the potential of being adopted as a real aid for skin cancer diagnosis. The probe has been tested both through full-wave numerical simulations and through measurements on a skin phantom realized at The University of Queensland with the support of the Microwave Team.
The study about gaseous plasma antennas for satellite communications has been mainly numerical. Different designs have been conceived with the aim of exploiting the advantages of using plasma elements while at the same time avoiding the limitations related to this novel technology. A practical implementation of these designs is now the subject of a collaboration with CISAS B. Colombo, an aerospace research center of the University of Padova.
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Grosser, Peter M. "Testosterone modulation of plasma gonadotropin and prolactin patterns." Thesis, McGill University, 1987. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=75750.
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The neuroendocrine sites and mechanisms of action whereby testosterone (T) regulates LH, FSH and prolactin signals in male rats were investigated by determining the effects of orchidectomy and graded T replacement on the secretion patterns of these hormones in blood. A chronic jugular catheter system was established to obtain blood samples at 5-10 min intervals from unrestrained, unanesthetized rats; this enabled moment to moment changes in plasma hormone concentrations, and thus hormone patterns, to be determined. In intact rats the patterns of LH and prolactin in plasma are pulsatile, but exhibit no synchrony; the FSH pattern shows no pulses. Post-orchidectomy LH concentrations rise due to increases in pulse amplitude and frequency; FSH also rises, but still no pulses are detected. Decreased prolactin pulse amplitudes result in lower plasma concentrations, despite an increase in pulse frequency. Treatment of orchidectomized rats with low doses of T increases mean LH and FSH concentrations, thus demonstrating that T is capable of exerting a positive feedback effect in males. The effect on LH is due to a stimulation of LH pulse amplitude which is not mediated at the pituitary. The FSH pattern becomes pulsatile and is synchronized with that of LH. Higher doses of T exert negative feedback on LH and FSH; LH pulse amplitude and frequency are decreased and the FSH pattern once again shows no pulses. These effects of T are partially due to inhibition of the pituitary response to LHRH. Low doses of T completely block the effects of orchidectomy on prolactin pulse amplitude, but T levels similar to those in intact animals are required to reverse the accelerated pulse frequency. The results suggest that gonadotropins and prolactin are regulated by separate pulse generators, each responsive to changes in plasma T. Furthermore, T, depending on its concentration, regulates gonadotropin and prolactin secretion by exerting stimulatory and/or inhibitory effects on various neur
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Wang, Dong. "Healthy Dietary Patterns, Plasma Lipid Metabolites, Cardiovascular Health and Mortality." Thesis, Harvard University, 2016. http://nrs.harvard.edu/urn-3:HUL.InstRepos:27201720.
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In Chapters 1 and 2, we examined two key components of heathy dietary patterns, specific types of dietary fat and consumption of fruit and vegetables, in relation to total and cause-specific mortality in two prospective cohort studies, the Nurses’ Health Study and the Health Professionals Follow-up Study. Dietary intake was assessed using semi-quantitative food frequency questionnaires at baseline and updated every 2 to 4 years. In Chapter 1, we found that higher saturated and trans fat intakes were associated with higher mortality, whereas polyunsaturated and monounsaturated fat intakes were inversely associated with mortality. Replacing 5% of energy from saturated fats with equivalent energy from polyunsaturated fats and monounsaturated fats was associated with 27% and 13% estimated reductions in total mortality, respectively. Intake of n-6 polyunsaturated fat, especially linoleic acid, was inversely associated with mortality, while marine n-3 polyunsaturated fat intake was associated with a modestly lower total mortality. In Chapter 2, we observed an inverse and nonlinear association between fruit and vegetable consumption and mortality. Consumption of five servings of fruit and vegetables daily, two servings for total fruit and three servings for total vegetables, were associated with the lowest total mortality, but above that level, higher consumptions were not associated with additional risk reductions. Higher consumptions of most fruit and vegetable subgroups were associated with lower risks of total mortality, whereas higher intakes of starchy vegetables such as peas and corn were associated with slightly higher risk of total mortality. In Chapter 3, we investigated the interrelationships between plasma ceramide concentrations, Mediterranean dietary pattern and cardiovascular disease (CVD) in the PREDIMED trial, a randomized controlled trial on the Mediterranean diet for primary prevention of CVD, using a case-cohort design. We observed strong positive associations between plasma ceramide concentrations and CVD risk. The association between ceramide concentration and incident CVD significantly varied by intervention groups. A Mediterranean diet may mitigate the deleterious effects of elevated plasma ceramide concentration.
In summary, our findings from the three studies support current dietary recommendations to replace saturated and trans fat with unsaturated fats, increase fruit and vegetable consumption and adopt healthy Mediterranean-style dietary patterns.
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Tan, Hua. "Extrémně rychlé slinování pokročilých keramických materiálů." Doctoral thesis, Vysoké učení technické v Brně. CEITEC VUT, 2020. http://www.nusl.cz/ntk/nusl-414113.
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Techniky rychlého slinování jako „Spark Plasma Sintering (SPS)“, „Flash Sintering“ (FS), „Selective Laser Sintering“ (SLS), „Induction Sintering“ (IS) a „Microwave Sintering“ (MS) jsou navrženy tak, aby účinně a předvídatelně kontrolovaly mikrostrukturu během slinovací proces. Spark Plasma Sintering jako jedna z nejmodernějších technik rychlého slinování a byla studována po celá desetiletí. V SPS má tři hlavní rysy: přímý ohřev elektrickým proudem, pulzní stejnosměrný elektrický proud a mechanický tlak. Mechanismy působení faktorů během SPS procesu však nejsou zatím jasně objasněny. Tato práce byla inspirována zvýšeným zájmem o techniky rychlého slinování a snahou o objasnění působení hlavních faktorů. Tato studie je rozdělena do čtyř částí: efekt elektromagnetického pole, efekt pulzního vzoru, tlakový efekt a přímý Joulův ohřev. Výsledky ukázaly, že elektromagnetické pole v SPS může být ignorováno, jak ukázaly simulace, a rovněž během experimentů nebyl nalezen žádný „efekt pole“. Na druhou stranu účinek pulzního vzoru byl významný, prášek TiO2 byl slinován pulzními vzory 12:2 a 10:9 s konstantním příkonem. Po aplikaci pulzního vzoru 10:9 došlo ke zvýšení velikosti zrna o jeden řád a ke zvýšení hustoty o 8%, zatímco množství spotřebované energie zůstalo konstantní. Při zahřátí s různými vzory pulzů se mění účinný výkon a kontaktní odpor indukovaný mechanickým pulsem, což jsou dva hlavní důvody, které vysvětlují měnící se energetickou účinnost. Vliv tlaku byl také významný, výsledky ukázaly, že použití tlaku při 900 ° C přineslo vysokou hustotu a malou velikost zrn, což vedlo k nejvyšší tvrdosti měřenou podle Vickerse. Interakce mezi tlakem a parami, vedoucí k rozdílné rychlosti přenosu páry v prvním slinovacím stupni, je považována za důvod pro rozdíly v mikrostruktuře, jako jsou mikropóry. Načasování mechanického tlaku může také podporovat difúzní mechanismy zhutňování během druhého slinovacího stupně, jako je difúze na hranicích zrn a mřížková difúze. Přímý ohřev, kdy se vede elektrický proud přímo skrz vzorek, vede k nízké měřené teplotě při slinování karbidu boru a jeho kompozitů, avšak teplota uvnitř vzorku je podstatně vyšší. Přidání slitiny titanu a křemíku do B4C významně zvýšilo finální hustotu, což byl hlavní důvod ovlivnění mechanických vlastností. Vzorek B4C + 1.0Ti (1 obj. % Ti slitiny) dosáhl nejvyšší tvrdosti 3628.5 ± 452.6 HV1 (16.2% vyšší než čistý B4C) s lomovou houževnatostí 2.11 ± 0.25 MPa m0.5. Zatímco při dopování křemíkem dosáhl vzorek B4C + 0.5Si (0.5 obj. % křemíku) nejvyšší tvrdosti 3524.6 ± 207.8 HV1 (o 13.0% vyšší než čistý B4C), vzorek B4C + 1.0Si dosáhl nejvyšší lomové houževnatosti 2.97 ± 0.03 MPa m0.5 (o 15.6% vyšší než čistý B4C). Velikost zrn kompozitů dotovaných titanem se oproti čistému karbidu boru byla o něco větší a mikrostruktura více nehomogenní. Naproti tomu se velikost zrn vzorků dotovaných křemíkem příliš nezměnila ve srovnání s velikostí zrn čistého karbidu boru. Sekundární fáze karbid křemíku byla dobře spojena s matricí karbidu boru a vykazovala pozitivní účinek jak na tvrdost, tak na lomovou houževnatost. Tato práce zkoumala vliv různých kontroverzních a nepopsaných aspektů na slinování keramických materiálů metodou Spark Plasma Sintering, což vedlo k lepšímu pochopení této techniky slinování.
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Ahner, Nicole. "Wetting Optimized Solutions for Plasma Etch Residue Removal for Application in Interconnect Systems of Integrated Circuits: Benetzungsoptimierte Reinigungslösungen für die Entfernung von Plasmaätzresiduen für die Anwendung im Verdrahtungssystem integrierter Schaltungen." Doctoral thesis, Universitätsverlag der Technischen Universität Chemnitz, 2011. https://monarch.qucosa.de/id/qucosa%3A19826.
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In multi-level Co/low-k based interconnect systems of ultralarge-scale integrated electronic devices the removal of plasma etch residues by common plasma cleaning processes has been shown to alter material properties like k-value and leakage current of the low-k dielectric. Besides the development of less damaging plasma processes their substitution by wet cleaning steps is in the focus of research and development. With further decreasing feature dimensions the development of wet cleaning processes has to include wetting issues like the non-wetting of small features due to the surface energy of the liquid or pattern collapse effects of low-k dielectric trenches due to high capillary forces This work at first focuses on the determination of the surface energetic character of common cleaning solutions for PERR and differently etched or ashed low-k dielectric surfaces by contact angle analysis, to outline which combinations of solid and liquid will be critical regarding their wetting behavior. Besides the determination of the wetting behavior the contact angle analysis turned out to be a fast and sensible analytic tool to understand the surface modifications introduced by different plasma processes and can help to understand the mechanisms of plasma damage of low-k dielectric surfaces. The analysis showed that especially polymerizing plasma etch processes produce a low-energetic low-k dielectric surface with a negligible polar energy contributions, which inhibits their wetting by high energetic water based cleaning solutions, which actually are favored by semiconductor manufacturers. The strategy to overcome these wetting issues followed in the present work is the reduction of the surface energy of the cleaning liquids by the application of surfactants. Several types of surfactants have been applied to the cleaning liquids and the compatibility of the surfactant solutions to BEOL materials like low-k dielectrics, copper and diffusion barriers as well as their dynamic behavior has been studied. The analysis showed that choosing the appropriate rinsing solution after the cleaning process is essential to ensure its compatibility to porous low-k dielectrics. Optical, electrical and structural data indicated that DIW rinse in most of the cases was not able to remove residual surfactant species within the material, while for an IPA rinse most of the residual surfactants have been removed. Considering the data received for compatibility to low-k materials, copper and barriers, the dynamic behavior of the surfactant solutions as well as influences of increased bath temperature and long term stability a general advice about surfactant selection and processing of surfactant aided solutions within BEOL is given.<br>In mehrlagigen Kupfer/low-k basierten Metallisierungssystemen hochintegrierter elektronischer Bauelemente kann die Entfernung von Residuen nach der Plasmastrukturierung des Dielektrikums mittels herkömmlicher Plasmareinigungsprozesse zur Schädigung der Isolatorschicht und damit zum Ansteigen der relativen Dielektrizitätszahl sowie der Leckströme führen. Neben der Entwicklung schädigungsarmer Plasmaprozesse stellt der Ersatz dieser Prozesse durch Nassreinigungsschritte zur Ätzresiduenentfernung eine vielversprechende Alternative dar. Mit stetig abnehmenden Strukturabmaßen ist bei der Entwicklung dieser Nassreinigungsprozesse neben der Materialkompatibilität auch das Benetzungsverhalten der Reinigungsflüssigkeit von entscheidender Bedeutung, da die Oberflächenenergie der Reinigungslösung das Eindringen dieser in kleinste Strukturen verhindern und es durch hohe Kapillarkräfte zum Kollaps von Grabenstrukturen im Dielektrikum kommen kann. In der vorliegenden Arbeit wurde zunächst mittels Kontaktwinkelanalyse die Oberflächenenergie verschieden prozessierter low-k Dielektrikaschichten sowie herkömmlicher Lösungen zur Entfernung von Ätzresiduen untersucht, um hinsichtlich ihres Benetzungsverhaltens besonders kritische Materialkombinationen aufzuzeigen. Neben der Bestimmung des Benetzungsverhaltens hat sich die Kontaktwinkelanalyse zur Oberflächenenergieberechnung als schnelle und empfindliche Methode zur Analyse der Auswirkung von Plasmaprozessen auf die Oberfläche von low-k Dielektrika erwiesen. Die Untersuchungen haben gezeigt, dass besonders polymerisierende Plasmaprozesse eine niederenergetische Oberfläche erzeugen, welche von den derzeit in der Halbleiterfertigung bevorzugten hochenergetischen wasserbasierten Reinigungslösungen nur schlecht benetzt wird. Um diesem Effekt entgegenzuwirken wurde in der vorliegenden Arbeit die Senkung der Oberflächenenergie der Reinigungslösungen durch Zugabe von Tensiden untersucht. Es wurden mehrere Tenside unterschiedlichen Typs den Reinigungsflüssigkeiten zugemischt und die Kompatibilität dieser Lösungen mit low-k Dielektrika, Kupferschichten und Diffusionsbarrieren untersucht sowie ihr dynamisches Verhalten analysiert. Dabei hat sich gezeigt, dass die Auswahl der geeigneten Spüllösung nach dem eigentlichen Reinigungsprozess von entscheidender Bedeutung ist. Optische, elektrische sowie strukturelle Daten deuten darauf hin, dass bei Verwendung einer Spülung mit deionisiertem Wasser in den meisten Fällen Tensidrückstände im porösen Dielektrikum verbleiben. Eine Spülung mit Isopropanol war hingegen in der Lage, einen Großteil dieser Tensidrückstände zu entfernen. Unter Einbeziehung der Daten zur Materialkompatibilität und dem dynamischen Verhalten der Tensidlösungen bei Raumtemperatur und erhöhter Badtemperatur sowie ihrer Langzeitstabilität konnte schließlich eine Prozessempfehlung für die Verwendung der benetzungsoptimierten Reinigungslösungen in der BEOL-Prozessierung gefunden werden.
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Hosokawa, Ricardo Shindi [UNESP]. "Delineação de padrões na superfície da poliamida por processo de plasma." Universidade Estadual Paulista (UNESP), 2016. http://hdl.handle.net/11449/147082.
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Previous issue date: 2016-11-17<br>Neste trabalho foi investigada a possibilidade de se criar padrões regularmente distribuídos sobre a superfície da poliamida (PA), utilizando o processo de deposição de filmes em plasmas de baixa pressão. Para tal, um único procedimento foi empregado utilizando-se uma malha metálica comercial (60 μm) como máscara para delinear pilares na superfície da poliamida. Os plasmas de deposição foram gerados a partir de atmosferas contendo 70% de hexametildisiloxano (HMDSO) e 30% de oxigênio a uma pressão total de 23 Pa, já incluído o valor de 3 Pa referente à pressão de fundo. O plasma foi ativado pela aplicação do sinal de radiofrequência (13,56 MHz, 150 W) no suporte de amostras enquanto o eletrodo superior permaneceu aterrado. O tempo de deposição, t, foi alterado de 15 a 90 min. Na etapa inicial do trabalho o filme foi uniformemente depositado sobre o polímero sem a utilização de máscara. Uma segunda etapa de experimentos foi realizada, utilizando-se condições idênticas às anteriores, mas com o auxílio da trama metálica sobre as amostras para guiar a deposição do filme somente nos poros da máscara. Filmes organosilicones, compostos por estruturas granulares e com espessuras dependentes de t, foram uniformemente depositados sobre a PA quando a máscara não foi utilizada. A deposição do filme independentemente da condição de t, aumenta a rugosidade superficial e transforma a amostra inicialmente hidrofílica em hidrofóbica. Muito embora t afete de forma suave a composição química, estrutura molecular e a molhabilidade do filme, seu efeito na espessura da camada é substancial. Padrões na forma de pilares foram regularmente definidos na superfície da PA com a deposição do filme organosilicone e a utilização da máscara. A altura dos pilares cresce com t alcançando até 1 µm. Para os maiores valores de t empregados, as máscaras não atuaram efetivamente como sombra na região dos fios. Observou-se que a molhabilidade da superfície ficou estável com o tempo de envelhecimento e não foi afetada pelos padrões.<br>In this work it was investigated the possibility of creating patterns regularly distributed on the surface of the polyamide (PA), using the process of film deposition in low pressure plasmas. For such, a single procedure was employed using a commercial metallic mesh (60 μm) as a mask to delineate pillars on the polyamide surface. The depositing plasmas were generated from atmospheres containing 70% of hexamethyldisiloxane (HMDSO) and 30% of oxygen at a total pressure of 23 Pa, already included the amount of 3 Pa related to the background pressure. The plasma was activated applying a radiofrequency signal (13.56 MHz, 150 W) to the sample holder while grounding the topmost electrode. Deposition time, t, was changed from 15 to 90 min. In the initial stage of the work the film was evenly deposited on the polymer without the usage of mask. A second step of experiments was performed, using the same conditions as earlier, but with the aid of the metallic frame on the samples to guide the film deposition only in the pores of the mask. Organosilicones films consisting of granular structures and thickness dependent of t were evenly deposited on the PA when the mask was not used. The film deposition, independently of condition of t, increases the surface roughness and transforms the sample initially hydrophilic to hydrophobic. Although t affects smoothly the chemical composition, molecular structure and wettability of the film, its effect on the layer thickness is substantial. Patterns in the form of pillars were regularly defined on the surface of PA with the organosilicon film deposition and the usage of the mask. The height of the pillars grows with t reaching up to 1 micrometers. For higher values of t, the masks did not act effectively as shadow in the wire region. It was observed that the surface wettability was stable with the aging time and it was not affected by the patterns.
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Mitchell, Stephen Alister. "Micro-patterned plasma and ultra-violet ozone modification of polymer surfaces." Thesis, Robert Gordon University, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.430030.
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Komarova, Natalia 1971. "Essays on nonlinear waves: Patterns under water; pulse propagation through random media." Diss., The University of Arizona, 1998. http://hdl.handle.net/10150/282787.
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This is a collection of essays on weakly and strongly nonlinear systems and possible ways of solving/interpreting them. Firstly, we study sand patterns which are often observed on sea (river) beds. One of the most common features looks like straight rolls perpendicular to the water motion. In many cases, the straight rolls are superimposed on a much longer wave so that two vastly different length scales coexist. In general, there are at least two mechanisms responsible for the growth of periodic sand waves. One is linear instability, and the other is nonlinear coupling between long waves and short waves. One novel feature of this work is to suggest that the latter can be much more important than the former one for the generation of long waves. A weakly nonlinear analysis of the corresponding physical system suggests that the nonlinear coupling leads to the growth of the longer features if the amplitude of the shorter waves has a non-zero curvature. For the case of a straight channel and a tidal shallow sea, we derive nonlinear amplitude equations governing the dynamics of the main features. Estimates based on these equations are consistent with measurements. Secondly, we consider strongly nonlinear systems with randomness. The phenomenon of self-induced transparency (SIT) is reinterpreted in the context of competition between randomness, nonlinearity and dispersion. The problem is then shown to be isomorphic to a problem of the nonlinear Schroedinger (NLS) type with a random (in space) potential. It is proven that the SIT result continues to hold when the uniform medium of inhomogeneously broadened two-level atoms is replaced by a series of intervals in each of which the frequency mismatch is randomly chosen from some distribution. The exact solution of this problem suggests that nonlinearity can improve the transparency of the medium. Also, the small amplitude, almost monochromatic limit of SIT is taken and results in an envelope equation which is an exactly integrable combination of NLS and a modified SIT equation. Some generalizations are made to describe a broad class of integrable systems which combine randomness, nonlinearity and dispersion.
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Ferré, Antoine. "Élaboration et caractérisation 3D de l’endommagement dans les composites amorphe-cristallins métalliques." Thesis, Lyon, INSA, 2015. http://www.theses.fr/2015ISAL0038.
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Les verres métalliques ont commencé à être produit dans les années 1960 et sous forme massive dans les années 1980. De nombreuses études se sont intéressées à ces matériaux sous leur forme amorphe et ont conclu qu’ils avaient une forte résistance mécanique mais présentaient un comportement très fragile. Dans le cadre du projet EDDAM débuté en 2011, ces matériaux ont été introduits sous forme de petites sphères dans une matrice d’aluminium. Le premier objectif de notre étude est de voir si le verre métallique sous cette forme permet de le rendre peu fragile. Le second objectif est de trouver une alternative aux renforts céramique dans les composites à matrice métallique qui présentent une faible cohésion à l’interface matrice/inclusion. Dans le but de caractériser l’endommagement dans des nouveaux composites amorphe-cristallins métalliques, la tomographie aux rayons X a été utilisée. Cette technique permet de caractériser de manière non destructive l’endommagement des matériaux et de le visualiser en 3D. Cela apporte une contribution à l’étude des matériaux composites par rapport aux techniques classiques utilisées. L’objectif général de cette thèse a été d’étudier l’endommagement en termes d’amorçage, de croissance et de coales- cence des matériaux composites amorphe-cristallins métallique par tomographie aux rayons X lors d’essais de traction monotone in situ. Les matériaux sélectionnés sont constitués d’une matrice aluminium ("molle" de type 1070A ou "dure" de type 5083) et de renforts en verre métallique Zr57Cu20Al10Ni8Ti5 de taille peu dispersée et répartis de manière homogène, avec différentes fractions volumiques (1%, 4% et 10%). Les matériaux composites ont été élaborés par la voie de la métallurgie des poudres au Spark Plasma Sintering (SPS) suivi d’une étape d’extrusion à chaud. Une attention particulière a été portée sur la caractérisation microstructurale des constituants de base. L’analyse qualitative a permis de comparer l’ensemble des composites fabriqués au SPS et ceux extrudés à chaud après SPS. Les différents modes d’amorçage de l’endommagement ont été observés ainsi que la croissance et la coa- lescence amenant la rupture des composites. L’analyse quantitative a été essentiellement consacrée au premier stade de l’endommagement. La croissance et la coalescence étant très rapide, il a été difficile de les suivre lors des essais interrompus. La modélisation d’un composite amorphe-cristallin métallique à matrice molle a été introduite dans le but de reproduire l’endommagement observé lors des analyses expérimentales. Cette première approche nécessite d’être approfondie dans le but de prédire, compte tenu des propriétés mécaniques des différentes phases et de la fraction volumique des renforts, le mode d’endommagement préférentiel apparaissant dans les composites étudiés. Elle montre cependant les prémices d’une modélisation innovante basée sur la microstructure expérimentale<br>Metallic glasses have been produced in the 1960s and bulk metallic glasses in the 1980s. Many studies, focused on these materials in their amorphous state, concluded that they had high mechanical strength but shown low ductility. As part of EDDAM project that started in 2011, these materials were introduced as small particles in an aluminum matrix. The first objective of this study is to see if the metallic glass is less brittle in this form. The second objective is to find an alternative of ceramic reinforcements in metal matrix composites. These materials have low cohesion at the matrix/inclusion interface. In order to characterize the damage in new amorphous-crystalline composite, X-ray tomography was used. This allows to characterize damage in materials and to obtain a 3D viewing. The main objective of this thesis was to study damage (nucleation, growth and coalescence) in composite materials using X-ray tomography during tensile tests. Selected materials are constituted of an aluminum matrix and small metallic glass reinforcements (Zr57Cu20Al_10Ni8Ti5). Composites with different volume fractions (from 1vol.% to 10vol.%) were prepared by Spark Plasma Sintering (SPS) and hot extrusion. A particular attention was paid to the microstructural characterization of the basic constituents. Qualitative analysis was used to compare SPS composites with SPS plus hot extrusion composites. Damage nucleation, growth and coalescence were observed. Quantitative analysis was mainly devoted to the first damage step. Growth and coalescence were difficult to follow due to fast rupture and interrupted tensile tests. The modeling of an amorphous-crystalline composite has been introduced in order to reproduce experimental damage analyses. The first approach requires further investigation to predict damage with different volume fractions. However, this part shows the beginning of an innovative model based on the experimental microstructure
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Rimal, Sirish. "Characterization of Post-Plasma Etch Residues and Plasma Induced Damage Evaluation on Patterned Porous Low-K Dielectrics Using MIR-IR Spectroscopy." Thesis, University of North Texas, 2016. https://digital.library.unt.edu/ark:/67531/metadc849694/.
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As the miniaturization of functional devices in integrated circuit (IC) continues to scale down to sub-nanometer size, the process complexity increases and makes materials characterization difficult. One of our research effort demonstrates the development and application of novel Multiple Internal Reflection Infrared Spectroscopy (MIR-IR) as a sensitive (sub-5 nm) metrology tool to provide precise chemical bonding information that can effectively guide through the development of more efficient process control. In this work, we investigated the chemical bonding structure of thin fluorocarbon polymer films deposited on low-k dielectric nanostructures, using Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). Complemented by functional group specific chemical derivatization reactions, fluorocarbon film was established to contain fluorinated alkenes and carbonyl moieties embedded in a highly cross-linked, branched fluorocarbon structure and a model bonding structure was proposed for the first time. In addition, plasma induced damage to high aspect ratio trench low-k structures especially on the trench sidewalls was evaluated both qualitatively and quantitatively. Damage from different plasma processing was correlated with Si-OH formation and breakage of Si-CH3 bonds with increase in C=O functionality. In another endeavor, TiN hard mask defect formation after fluorocarbon plasma etch was characterized and investigated. Finding suggest the presence of water soluble amines that could possibly trigger the formation of TiN surface defect. An effective post etch treatment (PET) methods were applied for etch residue defect removal/suppression.
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Kwon, Taesoon. "Evolution of patterned and unpatterned surfaces during high temperature annealing and plasma etching." College Park, Md. : University of Maryland, 2007. http://hdl.handle.net/1903/7251.
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Thesis (Ph. D.) -- University of Maryland, College Park, 2007.<br>Thesis research directed by: Material Science and Engineering. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
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MILANI, PAOLO. "The use of mass spectrometry for the diagnosis of plasma cell dyscrasias: focus on light chain (AL) amyloidosis patterns." Doctoral thesis, Università degli studi di Pavia, 2019. http://hdl.handle.net/11571/1285988.
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Santander, Mercado Alcides Ricardo. "Identification of Patient Recovery Patterns after Cardiovascular Surgery Based on Laboratory Tests Results." Scholar Commons, 2011. http://scholarcommons.usf.edu/etd/3332.
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In this dissertation is proposed a methodology to identify patient's recovery patterns after cardiovascular surgery based on laboratory tests results. The main purpose is to enhance the understanding of the manifestations of postsurgical complications in patients who underwent cardiovascular surgery. The analysis of patients' recovery process is based on the relationship between plasma calcium, ionized calcium and platelet count over time.
Laboratory results from the James A. Haley Veterans' Hospital databases, related to patients admitted to the Surgical Intensive Care Unit (SICU) after cardiac surgery (coronary artery bypass, aortic value replacement and mitral valve replacement), are used. These databases contain information regarding commonly ordered tests such as Complete Blood Count tests (CBC) and Basic Metabolic Panel (BMP) for a large group of patients over time. Physicians usually order these tests as a component of screening, routine evaluation, or serial assessment. These test results, contain a large amount of information used by most physicians during the diagnosis process and patient monitoring.
This study creates time series of some components of the aforementioned tests to analyze their behavior during the perioperative and postoperative period. Time series based clusters are developed to determine the similarities among tests results from four different types of patients: patients who had a satisfactory recovery process without any manifestation of complications, patients who experienced complications but survived,
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patients who experienced complications and then died during their recovery and patients who died during the perioperative period. As a conclusion, the time series based clustering techniques were able to identify whether a patient is likely to fully recover from the surgery, but it does not have the power to detect effectively results corresponding to a patient experiencing complications.
The development of this methodology provides statistical evidence of the differences among different patterns on patient recovery. It is clear that patients experiencing complications have a steeper drop of test results after surgery, and also a non-stable trend towards normal levels. The appropriate use of the proposed methodology could help to timely anticipate complications in patient condition, improve the comprehensiveness of the assessment of patient condition based on laboratory test results and enhance the utilization of laboratory results databases.
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Haddad, Farah. "Transmission electron microscopy study of low-temperature silicon epitaxy by plasma enhanced chemical vapor deposition." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLX107/document.
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Cette thèse s’intéresse à la croissance épitaxiale à basse température (~200°C) des couches minces de silicium par dépôt chimique en phase vapeur assisté par plasma (PECVD), pour des applications aux cellules solaires. L’objectif de départ était de mieux comprendre cette croissance épitaxiale, en utilisant la microscopie électronique en transmission (MET) comme principal outil expérimental. D’abord, nous avons étudié les premiers stades de cette croissance épitaxiale en chimie SiF4/H2/Ar, en menant une série de dépôts courts – quelques dizaines jusqu’à quelques centaines de secondes – sur différents types de substrats. Nous avons établi une corrélation entre les images MET de coupes et de vues planes et les mesures d’ellipsométrie in-situ. Nous avons discuté les mécanismes de croissance en nous basant sur l’hypothèse de la croissance traditionnelle à base d’atomes, radicaux et ions et l’hypothèse (relativement nouvelle) reposant sur la fonte des nanoparticules générées par le plasma au moment de l’impact avec le substrat. De plus, pour comprendre comment l’épitaxie par PECVD à basse température se maintient, nous avons étudié comment elle se brise ou se perd. Pour cela, des expériences de perte d’épitaxie ont été visées en augmentant soit la puissance de la source RF, soit le flux d’hydrogène, toujours pour une chimie SiF4/H2/Ar. Dans les deux cas, le mécanisme de brisure d’épitaxie fait intervenir des macles et des fautes d’empilement qui interrompent la configuration épitaxiale ; ceci est accompagné par une rugosification de surface. Grâce à cette nouvelle compréhension de la brisure d’épitaxie, nous proposons quelques moyens pour maintenir l’épitaxie pour de plus grandes épaisseurs. En outre, nous avons observé une fascinante quasi-symétrie cinq dans les diagrammes de diffraction pour ces couches et aussi pour d’autres élaborées par un plasma de chimie SiH4/H2/HMDSO/B2H6/Ar. Nous avons attribué une telle symétrie à une brisure d’épitaxie par l’intermédiaire d’un maclage multiple. Nous avons développé une méthode d’analyse quantitative qui permet de discriminer les positions de maclage de celles du microcristal aléatoire dans les diagrammes de diffraction et d’estimer le nombre des opérations de maclage. Nous avons aussi discuté quelques raisons probables pour l’incidence du maclage et du maclage multiple sous forme de symétrie cinq. Finalement, une importante réalisation pour le monde de la MET, durant ce travail doctoral, a été l’optimisation de la préparation traditionnelle d’échantillon (polissage par tripode). Nous l’avons transformée d’une méthode longue et ennuyeuse en une méthode rapide qui devient compétitive par rapport à la technique du FIB relativement chère<br>This thesis focuses on low temperature (LT, ~200°C) epitaxial growth of silicon thin films by plasma enhanced chemical vapor deposition (PECVD) for solar cell applications. Our starting goal was to acquire a better understanding of epitaxial growth, by using transmission electron microscopy (TEM) as the main experimental tool. First, we investigated the initial stages of epitaxial growth using SiF4/H2/Ar chemistry by performing a series of short depositions – from few tens to few hundred of seconds – on different types of substrates. We made a correlation between cross-sectional and plan-view TEM images and in-situ ellipsometry measurements. We discussed the growth mechanisms under the hypotheses of the traditional growth mediated by atoms, radicals and ions and the relatively new approach based on the melting of plasma generated nanoparticles upon impact with the substrate. Additionally, in order to understand how epitaxy by LT-PECVD is sustained, we studied how it is lost or how it breaks down. For that, experiments of intentional breakdown of epitaxy were performed by either increasing the RF power or the hydrogen flow rate using the same SiF4/H2/Ar chemistry. In both cases, the breakdown mechanism was based on the development of twins and stacking faults thus disrupting epitaxial configuration; this was accommodated with surface roughening. Thanks to this new understanding of epitaxy breakdown, we can propose some ways to sustain epitaxy for higher thicknesses. Moreover, we fascinatingly observed a quasi-fivefold symmetry in the diffraction patterns for these layers and for layers deposited using SiH4/H2/HMDSO/B2H6/Ar plasma chemistry as well. We attributed such symmetry to the breakdown of epitaxy through multiple twinning. We developed a quantitative analysis method to discriminate twin positions from random microcrystalline ones in the diffraction patterns and to estimate the number of twin operations. We also discussed some probable reasons for the occurrence of twinning and multiple twinning in a fivefold symmetry fashion. Finally, one important achievement to the TEM world is the optimization, during this doctoral work, of the traditional TEM sample preparation (tripod polishing), transforming it from a long and boring method to a fast method that is competitive with the relatively expensive focus ion beam (FIB) technique
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Zygridou, Smaragda. "Fabrication and characterisation of L10 ordered FePt thin films and bit patterned media." Thesis, University of Manchester, 2016. https://www.research.manchester.ac.uk/portal/en/theses/fabrication-and-characterisation-of-l10-ordered-fept-thin-films-and-bit-patterned-media(838fa936-fad2-422a-a1dc-ab852f77b6a6).html.
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Highly ordered magnetic materials with high perpendicular magnetic anisotropy (PMA), such as the L10 ordered FePt, and new recording technologies, such as bit patterned media (BPM), have been proposed as solutions to the media trilemma problem and provide promising strategies towards future high-density magnetic data storage media. L10 ordered FePt thin films can provide the necessary high PMA. However, the ordering of this material perpendicular to the plane of the films remains challenging since high-temperature and time-consuming processes are required. In this work, a remote plasma sputtering system has been used for the investigation of FePt thin films in order to understand if the greater control of process parameters offered by this system can lead to enhanced ordering in L10 FePt thin films at low temperatures compared with conventional dc magnetron approaches. More specifically, the effect of the different substrate temperatures and the target bias voltages on the ordering, the microstructure and the magnetic properties of FePt thin films was investigated. Highly ordered FePt thin films were successfully fabricated after post-annealing processes and were patterned into arrays of FePt islands. This patterning process was carried out with e-beam lithography and ion milling. Initial MFM measurements of these islands showed their single-domain structure for all the island sizes, which indicated the high PMA of the FePt. Magnetometry measurements were also carried out with a novel polar magneto-optical Kerr effect (MOKE) system which was designed and built during this project. This system has unique capabilities which are: a) the application of uniform magnetic field up to 2 Tesla, b) the rotation of the field to an arbitrary angle and c) the use of lasers of four different wavelengths. The combination of these abilities enabled measurements on ordered FePt thin films and patterned media which can pave the way for further highly sensitive measurements on magnetic thin films and nanostructures.
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Hook, Andrew Leslie, and andrew hook@flinders edu au. "Patterned and switchable surfaces for biomaterial applications." Flinders University. Chemistry, Physics and Earth Sciences, 2008. http://catalogue.flinders.edu.au./local/adt/public/adt-SFU20090210.161131.
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The interactions of biomolecules and cells at solid-liquid interfaces play a pivotal role in a range of biomedical applications and have hence been studied in detail. An improved understanding of these interactions results in the ability to manipulate biomolecules and concurrently cells spatially and temporally at surfaces with high precision. Spatial control can be achieved using patterned surface chemistries whilst temporal control is achieved by switchable surfaces. The combination of these two surface properties offers unprecedented control over the behaviour of biomolecules and cells at the solid-liquid interface. This is particularly relevant for cell microarray applications, where a range of biological processes must be duly controlled in order to maximise the efficiency and throughput of these devices. Of particular interest are transfected cell microarrays (TCMs), which significantly widen the scope of microarray genomic analysis by enabling the high-throughput analysis of gene function within living cells
Initially, this thesis focuses on the spatially controlled, electro-stimulated adsorption and desorption of DNA. Surface modification of a silicon chip with an allylamine plasma polymer (ALAPP) layer resulted in a surface that supported DNA adsorption and sustained cell attachment. Subsequent high density grafting of poly(ethylene glycol) (PEG) formed a layer resistant to biomolecule adsorption and cell attachment. PEG grafted surfaces also showed significantly reduced attachment of DNA with an equilibrium binding constant of 23 ml/mg as compared with 1600 ml/mg for ALAPP modified surfaces. Moreover, both hydrophobic and electrostatic interactions were shown to contribute to the binding of DNA to ALAPP. Spatial control over the surface chemistry was achieved using excimer laser ablation of the PEG coating which enabled the production of patterns of re-exposed ALAPP with high resolution. Preferential electro-stimulated adsorption of DNA to the ALAPP regions and subsequent desorption by the application of a negative bias was observed. Furthermore, this approach was investigated for TCM applications. Cell culture experiments demonstrated efficient and controlled transfection of cells. Electro-stimulated desorption of DNA was shown to yield enhanced solid phase transfection efficiencies with values of up to 30%. The ability to spatially control DNA adsorption combined with the ability to control the binding and release of DNA by application of a controlled voltage enables an advanced level of control over DNA bioactivity on solid substrates and lends itself to biochip applications.
As an alternative approach to surface patterning, the fabrication and characterisation of chemical patterns using a technique that can be readily integrated with methods currently used for the formation of microarrays is also presented. Here, phenylazide modified polymers were printed onto low fouling ALAPP-PEG modified surfaces. UV irradiation of these polymer arrays resulted in the crosslinking of the polymer spots and their covalent attachment to the surface. Cell attachment was shown to follow the patterned surface chemistry. Due to the use of a microarray contact printer it was easily possible to deposit DNA on top of the polymer microarray spots. A transfected cell microarray was generated in this way, demonstrating the ability to limit cell attachment to specific regions and the suitability of this approach for high density cell assays. In order to allow for the high-throughput characterisation of the resultant polymer microarrays, surface plasmon resonance imaging was utilised to study the adsorption and desorption of bovine serum albumin, collagen and fibronectin. This analysis enabled insights into the underlying mechanisms of cell attachment to the polymers studied. For the system analysed here, electrostatic interactions were shown to dominate cellular behaviour.
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Gowan, Timothy Adam. "Seasonal patterns of plasma testosterone levels, bite force, and locomotor performance in non-territorial male lizards, Aspidoscelis sexlineata by Timothy A. Gowan." Click here to access thesis, 2008. http://www.georgiasouthern.edu/etd/archive/fall2008/timothy_a_gowan/gowan_timothy_a_200808_ms.pdf.
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Thesis (M.S.)--Georgia Southern University, 2008.<br>"A thesis submitted to the Graduate Faculty of Georgia Southern University in partial fulfillment of the requirements for the degree Master of Science." Directed by Lance D. McBrayer. ETD. Includes bibliographical references (p. 41-61) and appendices.
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Shabbir, Aqsa [Verfasser], and Hartmut [Akademischer Betreuer] Zohm. "Pattern recognition in spaces of probability distributions for the analysis of edge-localized modes in tokamak plasmas / Aqsa Shabbir ; Betreuer: Hartmut Zohm." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2016. http://d-nb.info/1128593904/34.
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Kragten, Johannes Albertus. "New myocardial marker proteins in acute myocardial infarction quantitative aspects : release patterns of cellular enzymes and proteins in plasma following acute myocardial infarction /." Assen : Maastricht : Dekker & van de Vegt en Van Gorcum ; University Library, Maastricht University [Host], 1998. http://arno.unimaas.nl/show.cgi?fid=6052.
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Weckmann, Armin. "Material migration in tokamaks : Erosion-deposition patterns and transport processes." Doctoral thesis, KTH, Fusionsplasmafysik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-209758.
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Controlled thermonuclear fusion may become an attractive future electrical power source. The most promising of all fusion machine concepts is called a tokamak. The fuel, a plasma made of deuterium and tritium, must be confined to enable the fusion process. It is also necessary to protect the wall of tokamaks from erosion by the hot plasma. To increase wall lifetime, the high-Z metal tungsten is foreseen as wall material in future fusion devices due to its very high melting point. This thesis focuses on the following consequences of plasma impact on a high-Z wall: (i) erosion, transport and deposition of high-Z wall materials; (ii) fuel retention in tokamak walls; (iii) long term effects of plasma impact on structural machine parts; (iv) dust production in tokamaks. An extensive study of wall components has been conducted with ion beam analysis after the final shutdown of the TEXTOR tokamak. This unique possibility offered by the shutdown combined with a tracer experiment led to the largest study of high-Z metal migration and fuel retention ever conducted. The most important results are: - transport is greatly affected by drifts and flows in the plasma edge; - stepwise transport along wall surfaces takes place mainly in the toroidal direction; - fuel retention is highest on slightly retracted wall elements; - fuel retention is highly inhomogeneous. A broad study on structural parts of a tokamak has been conducted on the TEXTOR liner. The plasma impact does neither degrade mechanical properties nor lead to fuel diffusion into the bulk after 26 years of duty time. Peeling deposition layers on the liner retain fuel in the order of 1g and represent a dust source. Only small amounts of dust are found in TEXTOR with overall low deuterium content. Security risks in future fusion devices due to dust explosions or fuel retention in dust are hence of lesser concern.<br><p>QC 20170630</p>
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Li, Yong-Jun. "Adsorption processes and spatiotemporal pattern formation during electrochemical reactions on Au(111) film electrodes a surface plasmon resonance study /." [S.l. : s.n.], 2003. http://www.diss.fu-berlin.de/2003/73/index.html.
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Matcheswala, Akil Mannan. "GOLD NANOSPHERES AND GOLD NANORODS AS LOCALIZED SURFACE PLASMON RESONANCE SENSORS." UKnowledge, 2010. http://uknowledge.uky.edu/gradschool_theses/60.
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A novel localized surface plasmon resonance (LSPR) sensor that differentiates between background refractive index changes and surface-binding of a target analyte (e.g. a target molecule, protein, or bacterium) is presented. Standard, single channel LSPR sensors cannot differentiate these two effects as their design allows only one mode to be coupled. This novel technique uses two surface plasmon modes to simultaneously measure surface binding and solution refractive index changes. This increases the sensitivity of the sensor.
Different channels or modes can be created in sensors with the introduction of gold nanospheres or gold nanorods that act as receptor mechanisms. Once immobilization was achieved on gold nanospheres, the technique was optimized to achieve the same immobilization for gold nanorods to get the expected dual mode spectrum. Intricate fabrication methods are illustrated with using chemically terminated self assembled monolayers. Then the fabrication process advances from chemically silanized nanoparticles, on to specific and systematic patterns generated with the use of Electron Beam Lithography.
Comparisons are made within the different methods used, and guidelines are set to create possible room for improvement. Some methods implemented failed, but there was a lot to learn from these unsuccessful outcomes. Finally, the applications of the dual mode sensor are introduced, and current venues where the sensors can be used in chemical and biological settings are discussed.
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Silva, Francine Damian da. "Distribuição espacial e temporal de placas de esterco e produtividade da soja em sistema de interação soja-bovinos de corte." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2012. http://hdl.handle.net/10183/60952.
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O presente trabalho foi conduzido na região do Planalto Médio, RS, em protocolo experimental de longa duração, entre julho de 2010 e abril de 2011, constituído por dois experimentos. No experimento 1 foram realizadas amostragens das placas de esterco, em intervalos médios de 20 dias, em cada tratamento de altura de manejo do pasto (10, 20, 30 e 40 cm). Totalizaram-se seis avaliações ao longo do ciclo de pastejo, onde foram marcadas todas as placas de esterco do período. O número de placas por animal por dia, a área média e o peso das placas de esterco não diferiram entre os tratamentos. Áreas de Thiessen foram criadas para a análise geoestatística dos dados, para detectar o padrão da distribuição. Os bovinos depositaram suas placas de esterco em locais diferentes a cada período, não havendo um padrão de distribuição temporal. Considerando todas as amostragens verificou-se a existência de padrão na distribuição espacial das placas de esterco em relação aos pontos atrativos, independentemente do manejo de altura do pasto. No experimento 2 o delineamento experimental foi em arranjo fatorial 2x4, sendo dois tratamentos de presença de placas de esterco (com e sem) e quatro alturas de manejo do pasto. Para todas as variáveis analisadas, não houve interação entre as alturas de manejo do pasto e áreas com e sem presença de placas. Em áreas com presença de placas de esterco os teores de fósforo e potássio disponíveis no solo, assim como o componente do rendimento número de legumes por planta foram significativamente maiores, aumentando significativamente o rendimento de grãos da soja em relação às áreas sem placas. A presença dos animais no sistema de integração soja-bovinos de corte e, consequentemente, de suas placas de esterco aumentou a disponibilidade dos nutrientes fósforo e potássio nestes locais. Assim, afetou o teor destes nutrientes na planta, favorecendo a formação de maior número de legumes por planta e o rendimento de grãos da cultura da soja implantada em sucessão a pastagem.<br>This study was conducted at Planalto Médio region, RS, in the experimental protocol of long duration, between July 2010 and April 2011, consisting of two experiments. In Experiment 1 it was realized samples of dung, in intervals of 20 days in each treatment of sward height (10, 20, 30 and 40 cm). Six evaluations were amounted from that period have been marked over the grazing cycle, where all dung did not vary between the treatments. The number of dung per animal per day, the average size and weight of the dung not different among treatments. Thiessen areas were created for the geostatistical analysis of the data to detect the pattern of distribution. The cattle deposited their dung in different places every time, without a pattern of temporal distribution. Considering all samples it was verified the existence of a pattern in spatial distribution of dung in relation to the attractions points, independently of the management of the sward height. In experiment 2, the experimental design was a 2x4 factorial arrangement, with being two treatments of presence of dung (with and without) and four different sward heights. For all variables analyzed, there was no interaction between sward heights and areas with and without dung. In areas with dung the levels of available phosphorus and potassium in the soil, as well as the yield component number of pods per plant were significantly higher, significantly increasing the grain yield of soybean in relation to areas without dung. The presence of animals in the integrated soybean-beef cattle system and consequently their dung increased the availability of nutrients, phosphorus and potassium in these locations. Thus, affected the content of these nutrients in the plant, favoring the development of the number of pods per plant and grain yield of soybean.
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Azevedo, Leandro Augusto da Cunha. "Estudo sobre as mudanças fenotípicas conferidas por plasmídios R provenientes de Klebsiella pneumoniae e Escherichia coli em transconjugantes de E. coli K12-R23." Universidade do Estado do Rio de Janeiro, 2011. http://www.bdtd.uerj.br/tde_busca/arquivo.php?codArquivo=6152.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico<br>Plasmídios são DNA extracromossômicos, com capacidade de se duplicarem de forma independente das células que os albergam, e são responsáveis pela expressão de uma variedade de características, como fatores de virulência. O material do presente estudo se constituiu da cepa receptora E. coli K12-R23, e de
cepas de Klebsiella pneumoniae e de Escherichia coli, doadoras de plasmídios R e transconjugantes. O objetivo do presente estudo foi analisar os fenótipos conferidos
em cepas transconjugantes de ambas bactérias pela transferência de plasmídios R de cepas doadoras para a receptora. Para a análise dos fenótipos, utilizaram-se, nas cepas do estudo, algumas variáveis: sensibilidade a antimicrobianos e a ERO, aderência a células HEp-2, e formação de slime e de biofilme. O marcador da
presença de plasmídio, neste trabalho, foi a presença de resistênca à gentamicina nas cepas doadoras. Os resultados indicaram que houve transferência de plasmídio, pois as cepas transconjugantes de K. pneumoniae e de E. coli apesentaram este marcador (foram resistentes à gentamicina); além disso, as cepas transconjugantes mostraram perfis distintos da receptora em relação à sensibilidade aos antimicrobianos, às ERO, aos padrões de aderência às células HEp-2 e à formação de slime, apesar de a formação de biofilme nestas cepas não ter sofrido
modificações. Observou-se, contudo, que várias características das cepas doadoras não foram encontradas nas cepas transconjugantes de E. coli e de K. pneumoniae.<br>Plasmids are extrachromosomal DNA that have the ability to duplicate independently of the host cells. Plasmids are responsible for the expression of a variety of characteristics of the cells, such as virulence factors. The present study utilized a receptor strain of E. Coli K12-R23 and strains of Klebsiella pneumoniae and E. coli which were R plasmids donor strains and transconjugant ones. The objective of this study was to analyze the attributed phenotypes of transconjugant strains in both bacteria caused by transference of R plasmids from the donor strains to the receptor ones. In order to analyze these phenotypes, the following variables were selected: sensitivity to antimicrobials and ROS, adherence to HEp-2 cells, and slime and biofilm structures. The marker of the presence of plasmids was gentamycin resistance in the donor strains. The observed results indicated that there was plasmid transfer; given that Klebsiella pneumoniae and E. coli strains presented the marker (e.g. they became resistant to gentamycin). Moreover, transconjugant strains
have showed distinct profiles from the receptor strain concerning sensitivity to antimicrobials, ROS, adherence patterns to HEp-2 cells and slime structure. On the other hand, the biofilm structure of these strains did not present modifications. Yet, it was observed that several characteristics of the donor strains were not found in the
transconjugant strains of E. coli and K. pneumoniae.
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Stingel, Erich. "Distribuição espacial e plano de amostragem para a cigarrinha-das-raízes, Mahanarva fimbriolata (Stal., 1854), em cana-de-açúcar." Universidade de São Paulo, 2005. http://www.teses.usp.br/teses/disponiveis/11/11146/tde-27072005-140222/.
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O objetivo deste trabalho foi avaliar a distribuição espacial de adultos e ninfas da cigarrinha-das-raízes da cana-de-açúcar, Mahanarva fimbriolata (Stål., 1854) (Hemiptera: Cercopidae), a eficiência do sistema de amostragem atualmente empregado em escala comercial, a possibilidade de estimar a população de ninfas por meio da contagem de espumas e, a partir desses resultados, estabelecer um plano de amostragem confiável, prático e de baixo custo para utilização em programas de manejo integrado desta praga. A determinação da distribuição espacial foi feita em Ourinhos e Guariba-SP, demarcando-se três parcelas de 1,1 ha, em talhão colhido mecanicamente sem a queima da palha e com histórico de ataque da cigarrinha-dasraízes. As avaliações foram feitas em três épocas diferentes, contando-se o número de adultos e ninfas na base das touceiras, em 50% da área da parcela. Os adultos e ninfas de M. fimbriolata distribuem-se de forma agregada ou contagiosa na cultura da cana-de-açúcar e este padrão de distribuição não se altera ao longo das gerações, nem é influenciado pelo nível de infestação ou variedade cultivada. Utilizando-se os dados obtidos nestes experimentos calculou-se, para cada local e época de amostragem, o índice de dispersão k e o número de amostras necessárias para estimar a população de ninfas, considerando-se diferentes níveis de precisão, e realizaram-se simulações para diferentes tamanhos de amostra e esquemas de caminhamento. O plano de amostragem mais adequado para avaliação da população da cigarrinha-das-raízes em cana-de-açúcar foi determinado por meio do intervalo de confiança da média (P ≤ 0,05) para a Variação Relativa (VR) e Precisão Relativa (PR). Os melhores resultados foram obtidos com 18 amostras de 1 metro linear por hectare, distribuídas na área de forma sistemática. Para a avaliação do método de amostragem comercial, instalaram-se dois experimentos em Ourinhos, demarcando-se duas parcelas de 1,1 ha, nas mesmas condições anteriores. Quinzenalmente, quantificou-se o número de formas biológicas em 300 pontos de 1m linear na parcela (amostragem experimental) e no restante da área do talhão (amostragem comercial), em 4 pontos de dois sulcos de 2m lineares/ha. Comparando-se os dados por meio de uma análise de regressão linear verificou-se que o método de amostragem comercial apresentou boa precisão na estimativa da população de ninfas, porém foi pouco preciso para adultos. Sua acurácia foi baixa para ninfas e adultos, subestimando as populações reais. A relação entre as contagens de espumas e ninfas nas amostragens comercial e experimental foi avaliada por meio de uma análise de regressão linear, observando-se alta correlação entre estes parâmetros, com coeficientes de determinação superiores a 0,96. Os resultados obtidos indicam que, independentemente da época de avaliação e do nível de infestação, é possível estimar a população de ninfas da cigarrinha-dasraízes em cana-de-açúcar por meio da contagem de espumas, com elevado grau de confiabilidade.<br>The objective of this research was to evaluate the spatial distribution of adults and nymphs of the sugarcane root froghopper, Mahanarva fimbriolata (Stal, 1854) (Hemiptera: Cercopidae), to evaluate the efficiency of the sampling system presently used to monitor the populations in commercial fields, and to estimate nymph populations by counting foam spots. The results obtained in this work were used to establish a low cost and reliable sampling method in order to improve the integrated pest management program for the sugarcane root froghopper. The determination of the spatial distribution was conducted at Ourinhos and Guariba cities, São Paulo State, in three plots of 1.1 ha that had been mechanically harvested without burning and with a history of infestation with sugarcane root froghopper. The evaluations were made in three different periods, counting the number of both adults and nymphs at the base of the stools in 50% of the plot. The adults and the nymphs of M. fimbriolata were distributed in aggregated or contagious form and this pattern did not change during subsequent generations nor was influenced by either the level of infestation or cultivated variety. The data obtained in these experiments was used to estimate, for each site and sampling period, the dispersion index k and the number of samples needed to estimate nymph populations, considering different levels of precision. The data was also used to simulate results with different sample sizes and sampling patterns. The most adequate sampling plan to evaluate sugarcane root froghopper populations was determined using the confidence interval of the mean at P ≤ 0.05 for the Relative Variation (RV) and Relative Precision (RP). The best results were obtained with 18 samples of 1 linear meter per hectare, distributed in the area in a systematic manner. For the evaluation of the commercial sampling method, two experiments were established at Ourinhos, using two 1.1 hectare plots. The number of biological forms in 300 spots of 1 linear meter in the plot (experimental sampling) were checked bi-weekly. Similarly, in the rest of the area, biological forms were counted in 4 spots of 2 linear meters per hectare (commercial sampling). Linear regression analysis presented that the commercial sampling method presented good efficiency for estimating nymphs populations but was not efficient in estimating adult populations. The sampling accuracy was low for both nymphs and adults, underestimating the true populations. The linear correlation between foam counts and nymph in both commercial and experimental sampling was high, with determination coefficient greater than 96%. The results indicate that, independent of the period and level of infestation, it is possible to estimate the population of sugarcane root froghopper nymphs by counting foam spots.
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Steinebach, Mario, Alexander Friebel, Christine Häckel-Riffler, et al. "TU-Spektrum "Sonderausgabe Auto & Verkehr" 2004, Magazin der Technischen Universität Chemnitz." Universitätsbibliothek Chemnitz, 2004. http://nbn-resolving.de/urn:nbn:de:swb:ch1-200400909.
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Santos, Ana Paula de Oliveira. "Desenvolvimento de descritores de imagens para reconhecimento de padrões de plantas invasoras (folhas largas e folhas estreitas)." Universidade Federal de São Carlos, 2009. https://repositorio.ufscar.br/handle/ufscar/416.
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Previous issue date: 2009-06-05<br>Universidade Federal de Sao Carlos<br>In Brazil, the development of tools for weeds recognition, capable of aiding risk detection and decision making on the fieldwork is still embryonic. This master s thesis presents the development of a pattern recognition system that recognizes weeds and gives the occupation percentage of wide and narrow leaves in an agricultural production system, with digital image processing techniques. The development was based on considerations about image acquisition, pre-processing, texture based segmentation, descriptors for weeds recognition and occupation percentage of each kind of leaf. The validation has been developed considering geometric patterns generated in laboratory, as well as others obtained of a maize (Zea mays) production agricultural environment, i. e. two species of weeds, one with wide leaves (Euphorbia heterophylla L.) and other with narrow leaves (Digitaria sanguinalis Scop.). The results show recognition of about 84.24 percent for wide leaves and 80.17 percent for narrow leaves in agricultural environment and also the capability to spot weed on unreachable locations by natural vision. Besides, the method presents application in precision agriculture to improve the decision making in pulverization processes.<br>No Brasil é ainda embrionário o desenvolvimento de ferramentas de reconhecimento de plantas invasoras, capazes de auxiliar a tomada de decisão e indicar o seu risco no sistema de produção. Este trabalho apresenta o desenvolvimento de um sistema de reconhecimento de padrões de plantas invasoras e percentuais de ocupação de folhas largas e folhas estreitas, em sistemas de produção agrícola, utilizando técnicas de processamento digital de imagens. Para o desenvolvimento houve a consideração das etapas de aquisição das imagens, pré-processamento, segmentação baseada em textura, descritores para o reconhecimento das plantas invasoras e percentual de ocupação de cada tipo de planta. A validação foi desenvolvida considerando padrões geométricos gerados em laboratório, bem como o próprio ambiente de produção agrícola de milho (Zea mays), tomando por base duas espécies de plantas invasoras, sendo uma de folha larga (Euphorbia heterophylla L.), e outra de folha estreita (Digitaria sanguinalis Scop.). Resultados indicam uma taxa de acerto no reconhecimento em ambiente de campo da ordem de 84,24% para folhas largas e da ordem de 80,17% para folhas estreitas, além da capacidade de identificar plantas invasoras em locais restritos a visão natural. Adicionalmente, o resultado obtido apresenta potencial para a aplicação no manejo baseado em agricultura de precisão, o que auxilia na tomada de decisão em pulverização agrícola.
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Martins, Amanda Eburneo. "Padrões de cores de flores e a polinização em vegetações sazonais /." Rio Claro, 2019. http://hdl.handle.net/11449/191419.
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Orientador: Leonor Patricia Cerdeira Morellato<br>Resumo: A visão é o principal sentido utilizado pelos polinizadores para forragear, no qual a cor das flores é a primeira característica de atração. A percepção dos sinais de cores depende da coloração do segundo plano das flores, composto principalmente pelas folhas. Diferenças na composição das espécies e na estrutura da vegetação, e também na sazonalidade climática, podem interferir na cor do segundo plano de folhas em diferentes vegetações e estações, interferindo como os polinizadores percebem a flor. Portanto, a diversidade de cores das flores e os padrões de floração de uma comunidade podem estar relacionados com a composição de polinizadores e condições ambientais. Desta maneira, utilizando comunidades vegetais e considerando o sistema visual das abelhas, nós descrevemos e comparamos a diversidade de cores das flores e seus sinais, dando importância para a cor do segundo plano de folhas em duas vegetações sazonais tropicais e uma vegetação sazonal temperada. Em seguida, para vincular os sinais florais com a sazonalidade, nós analisamos a importância das síndromes de polinização levantadas, o padrão de floração, a influência da cor do segundo plano de folhas no padrão de cor das flores entre as estações. Nós encontramos diferenças na diversidade de cores das flores e confirmamos a influência da coloração do segundo plano de folhas, juntamente com a estrutura da vegetação e a intensidade da sazonalidade nos sinais florais exibidos em diferentes vegetações sazonais, de acordo co... (Resumo completo, clicar acesso eletrônico abaixo)<br>Abstract: Vision is the main sense used to forage by pollinators being the flower colour the primary feature of attraction. Colour signals perception depend on the flower background colouration, mainly composed by leaves. Differences in species composition and vegetation structure, and also the seasonality, may change the leaf-background colouration of different vegetations and seasons, interfering how the pollinators perceive a flower. Therefore, flower colour diversity and flowering patterns of a community may be related to the pollinators’ composition and environmental conditions. Using a community level-approach and according to bee visual system, we described and compared the flower colour diversity and the signals of a temperate and two tropical seasonal vegetations, considering their leaf background colouration. Then, to link flower signals to seasonality and using the cerrado sensu stricto as a model of seasonal vegetation, we analysed the importance of the surveyed pollination syndromes, the community flowering pattern, flowering patterns according to the colour of flowers and the influence of seasonal changes in the background colouration in the flower colour signals between seasons. We found differences in flower colour diversity and confirmed the influence of the leaf- background colouration, along with the vegetation structure and seasonality intensity, in flower colour signals displayed in different seasonal vegetations according to the colour vision of bees. Higher value... (Complete abstract click electronic access below)<br>Mestre
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Du, Ji-Bin, and 杜志彬. "Pattern formation in weakly ionized plasma." Thesis, 1994. http://ndltd.ncl.edu.tw/handle/35200634258491187529.
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Vijayan, Vinesh. "Dynamics, Synchronization and Pattern Formation in Coupled Thomas Oscillators." Thesis, 2022. http://ethesis.nitrkl.ac.in/10361/1/2022_PhD_VVijayan_513PH3005_Dynamics.pdf.
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This thesis work is mainly about dynamics, synchronization and pattern formation in coupled Thomas oscillators in the chaotic regime. Two mutually coupled identical oscillators as well as oscillators in a network are considered. The synchronizability of Thomas oscillators on various networks are established via master stability function formalism under linear coupling scheme for identical setting of oscillators. For pattern formation, local, nonlocal, global coupling schemes on a ring are considered. The special nature of Thomas oscillators and its connection to active Brownian particles are established via numerical simulations. The study of dynamics and synchronization of two mutually coupled oscillators are based on the calculations of Lyapunov exponents, Bifurcation diagram, phase portrait, Transverse Lyapunov exponents, Pearson coefficients, Transverse distance and similarity index. Two different values of system parameter are used in the chaotic regime under linear and nonlinear coupling schemes. In both cases the coupled system undergoes a period of transient chaos. Three different types of initial conditions are used to study the transients and synchronization. For low value of coupling strength, the system shows weak forms of synchronization. For linear coupling, the nature of synchronization agrees with the predictions of the general observation found in prototypical Rössler system and Lorenz system. The nature of synchronization is much more complex in the case of nonlinear coupling. The system bifurcates to lag or anti-lag synchronization even after achieving complete synchronization. It also shows space-lag(swarming) and multistability with nonlinear coupling. The emergence of lag or anti-lag is confirmed with similarity index calculation. Our calculation of largest transverse Lyapunov exponent for nonlinear coupling exactly matches with the predictions of Pearson coefficient and Transverse distance which would have been lost on any linearization of the transverse perturbation equation for the coupled system. The variables in our system are components of velocity of a particle moving in a force field and indeed, there are velocity-velocity correlations like in coupled active Brownian particles. Therefore, we claim that the stochastic dynamics of active Brownian particles can be modeled by chaotic dynamics of Thomas system. We found the important results that lag / anti-lag and space lag(swarming) synchronization within the regime of complete synchronization. The synchronization properties of Thomas oscillators in a network is studied for identical oscillators with linear coupling scheme via master stability function formulation. For the set of system parameters in the chaotic regime, they show type-I and type-II behavior of MSF. The synchronizability for various network architectures are also studied. For the study of pattern formation, we considered hundred Thomas oscillators on a
ring with nonlocal coupling with nonlinear coupling function. We could achieve chimera states for a certain range of intermediate coupling constants. The Chimera states are quantified by means of strength of incoherence and discontinuity measure calculation. The system shows cluster, chimera, multi-chimera as the coupling is increased. We could also achieve chimera states for nearly local coupling with nonlinear coupling functions. The global coupling shows complete synchronization of oscillators. The obtained result of pattern formation in the network is useful to understand the dynamics of active Brownian particles. For active Brownian particles, the probability distribution of velocities resembles the present observation of the chimera states. The discontinuous jump observed in the case of zero system parameter corresponds to a first order phase transition and matches with the statistical model of self-propelled particles.
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Lee, Hong-Gen, and 李宏根. "Viscous fingering pattern of the plasma bubble in a narrow gap." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/57012278932453461468.
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碩士<br>國立中正大學<br>物理學系暨研究所<br>99<br>The silicon oil is filled in two parallel ITO glass plates and atmospheric
gas are injected into the silicon oil layer as a gas bubble. For turning on
the plasma, the gas bubble plays the role of gas chamber. We study the
beautiful radial evolution of the plasma bubble. By counting the luminescent
area of the plasma bubble and the shape of the gas bubble, we classify the
evolution of the plasma bubble with three stages. The bubble starts to
deform by temperature fluctuation on the boundary which is induced by ion
bombandments. We also show how to generate and to control the beautiful
radial evolution by changing the experimental parameters in different scales.
Thses controlled parameters are find some relations between the wavelength,
, of the plasma bubble. In the process of the plasma bubble evolving into
the radial fingering plasma bubble, there are bright spots in the fingertips
which are observed with microscope and it is found that some microbubble
are ejected from the tips. The radial fingering looks like the fractal pattern
and the fractal dimension of the fingering plasma bubble is found about 1.74
by sandbox method.
i
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Niu, Chen-Yi, and 牛振儀. "Improving GaN-based LED performance by plasma treated wet-etched pattern-sapphire-substrates." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/60701071358721574585.
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碩士<br>國立交通大學<br>材料科學與工程學系<br>100<br>In choosing the way to fabricate patterned sapphire substrate ( PSS ), standard photolithography and wet-etching are preferred process is because of their lower cost, higher throughput than dry-etching process. However, several facets ( sidewalls ) on PSS formed by wet-etching are observed, and these facets will influence the structure of the subsequent GaN epitaxy layer. Instead of normal wurtzite GaN, a disparate zincblende GaN has been found on these facets. Meanwhile, irregular voids have been found in the GaN epitaxy film during the GaN coalescence process. All of the above situations will affect the efficiency and performance of LED.
In this study, wet-etched patterned sapphire substrates were treated by BCl3-based plasma. Through the reaction between sapphire surface and BCl radicals, the opportunity of growth of GaN on sapphire sidewalls was changed. Also, the effect of BCl3-based plasma on the performance of LEDs was investigated.
The results of device measurement showed that the PSS with plasma treatment–LED-DWPSS owned improved output power. At 350mA, the output power of LED-WPSS、LED-DWPSS I ( plasma treatment time : 300 sec )、LED-DWPSS II ( plasma treatment time : 600 sec ) were 425.5 mW、437.6 mW and 453.8 mW, respectively. The output power of LED-DWPSS II was 6.7% larger than LED-WPSS, and 3.7% larger than LED-DWPSS I.
Besides, from the results of PL, XRD and EPD, we conclude that plasma treatment could improve the quality of MQW and GaN epi-layer, and reduce the number of threading dislocations as well. From TEM and STEM cross-section images of GaN film on substrate facets, we found that the number of dislocations on DWPSS II was reduced and the size of GaN grains decreased as plasma treatment time increased.
All of experimental results revealed that the additional plasma treatment could restrain the growth of GaN grains on facets on PSS and thus improved the performance of device.
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"LONG-TERM VARIATIONS IN THE HIGH-LATITUDE PLASMA FLOWS INFERRED FROM SUPERDARN RADAR DATA." Thesis, 2015. http://hdl.handle.net/10388/ETD-2015-04-2041.
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ABSTRACT
This Thesis investigates ionospheric plasma flows (commonly referred to as “convection”) at high latitudes with the objectives to assess seasonal and solar cycle variations in the shape of the flow patterns and the flow intensity in terms of external drivers of the flow, first of all the magnitude and orientation of the interplanetary magnetic field (IMF). Multi-year (2001-1011) line-of-sight Doppler velocity data collected by the Super Dual Auroral Network (SuperDARN) HF radars are considered. Two approaches are used: 1) analysis of monthly-averaged 2-dimentional patterns inferred from data of all SuperDARN radars operated and 2) analysis of near magnetic noon data from only two SuperDARN radars, Rankin Inlet and Inuvik monitoring meridional component of the flow in the near North Pole areas (polar cap). We show and discuss seasonal and solar cycle variations of three characteristics of the flows: magnetic latitudes of the region where plasma flow direction changes from toward the noon to away from the noon (convection reversal boundary), the magnetic local time location of the near noon region with stagnated flow (throat region) and, finally, the magnitude of the flow. All three parameters show trends, although not strong and consistent all the time, which agrees with previous publications where different analysis approaches and more limited data sets were used. For two specific points, one at the magnetic latitude of 72 degrees, representing the auroral oval latitudes (region where optical arcs occur most frequently) and the other one at 82 degrees, representing the polar cap latitudes we demonstrate that the average flow magnitude increases with the IMF intensity, and the effect is much stronger for the negative vertical component of the IMF Bz. In our second approach we demonstrate that the flow velocity increases almost linearly with an increase of the reconnection electric fields characterizing processes of interaction between the solar wind/IMF and the Earth`s magnetic dipole. Saturation effect is seen for strongest electric field. More clear seasonal effects are noticeable in these data; the velocity response to the reconnection electric field enhancement is stronger summer (winter) time for positive (negative) IMF Bz. The data are consistent with previous reports, where highly smoothed velocity data were considered.
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Chuang, Ta-Wei, and 莊大緯. "Fabrication and Characteristics of Nano-Pattern on Sapphire Substrate by Transformer Coupled Plasma Etching Technology." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/3bg8zk.
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碩士<br>國立虎尾科技大學<br>光電與材料科技研究所在職專班<br>98<br>The LED basically is an electro-optic conversion components, The component has two electrodes terminal, in the terminal voltage between leads to extremely low current, through the integration of electronic power cave, the remaining energy in the form of visual light fires release. Therefore, basically we can be LED as lighting components, for purposes of all the lighting components, electro-optic conversion (luminance) is the core of all technology and product development issues.
Therefore, we could treat LED as kind of light element. For all the lighting elements, electric/luminous transforming technique would be the key topic for developing of technique & products. For lighting application, currently there are LED & traditional lighting elements. By reviewing the cost & market share of traditional lighting elements, if LED would like to be popular & common as traditional lights, the price would be the first essential factor. There are two challenges to make LED displaceable the traditional lighting, one is reduce the cost & enhance the lighting efficiency of LED.
This article is a successful use of variable-coupled plasma etching technique to nano-patterned Sapphire substrate, and the direction by substrate etching, etching deep and crystal defect density in the corner, in-depth analysis on this with nano-patterned Sapphire substrate of light-emitting diode with traditional flat substrate of light-emitting diode and micron patterned the difference between the Sapphire substrate.
By dry etching techniques as well as nano-coating technology for spherical and sinister, preparation for Nanotech patterned Sapphire substrate, it is consistent with the mass production conditions, also reduce process required for the cost and time, better control of the substrate etching uniformity and depth, making a variety of nano-pattern to the Sapphire substrate.
Growth of gallium nitride material satisfy in the nanotech patterned Sapphire substrate , is only available with a superior quality of crystal, also increase the LED quantum efficiency of internal and external lighting efficiency, makes the LED have best performance characteristics.
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山本, 洋., and Hiroshi YAMAMOTO. "Studies on Plasma Etching Process of Low Dielectrics for Fine Pattern Profile Control with Less Damage." Thesis, 2012. http://hdl.handle.net/2237/16473.
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Li-Yun and 謝禮雲. "Comparison of intake and plasma levels of vitamin A and carotenoids in COPD patients and healthy people: the association with diet pattern." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/59723055669923476592.
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碩士<br>中山醫學大學<br>營養學研究所<br>97<br>Oxidative stress is thought to play a key role in the pathogenesis of COPD. Increasing evidence suggested that individuals with a high intake of antioxidative nutrients, such as vitamins C, E, A, and carotenoids tend to maintain better lung function. However, little has been known about the intakes status of these nutrients in COPD patients in Taiwan. Therefore, this case-controlled study elucidated the differences in plasma and intake levels of vitamin A and various carotenoids as well as the association of the plasma concentration of these nutrients and endogenous and H2O2-induced white blood cells (WBC) DNA damage. In addition, we investigated whether the dietary habits of avoiding “cooling” vegetables and fruits affect the intake of these nutrients. Thirty-two COPD patients, who satisfied the criteria with forced expiratory volume in 1 second (FEV1) % predicted less than 80% and a ratio of FEV1 to forced vital capacity (FVC) less than 0.7, were recruited in this study; whereas, forty-three healthy people, who were ≧ 50 years old and with normal lung function, were recruited as control group. We compared the dietary habits and nutrient intakes using a food frequency questionnaire and a 24-h food recall. Blood samples were collected to measure the level of vitamin A, α-carotene, β-carotene, lutein and lycopene. The results showed that the mean intakes of vitamin A, individual carotenoid except for α-carotene or total carotenoids in COPD patients were significantly lower than those of healthy people. On the other hand, the mean plasma concentrations of vitamin A, individual carotenoid except for lutein and lycopene, or total carotenoids were also significantly lower in COPD patients than those of healthy individuals. Furthermore, we investigated the associations between these nutrients with DNA damage in white blood cells (WBC), because the previous study in our lab showed that the endogenous and H2O2-induced WBC DNA damage of COPD patients were significantly higher than those of healthy people. Pooling the data of the two groups showed that total carotenoids concentration was significantly inversely correlated with the H2O2-induced WBC DNA damage (β= -5.343, p=0.043).However, after adjusted for confounders, the inverse association was not statistically significant. In addition, the sum vegetable and fruit intakes frequency of COPD patients was significantly lower than that of healthy people, especially in cooling items. In both COPD and healthy groups, the total consumption of vegetables and fruits was significantly positively associated with the intake of dietary vitamin A,β-carotene, lutein, and total carotenoids; whereas the consumption of cooling items were positively associated, with a borderline significance, with the intake of vitamin A in both groups after adjustment for confounders. After adjusting for confounders, the total consumption vegetables and fruits, rather than each individual nutrient, reduced the OR for COPD. In summary, COPD patients in Taiwan have lower levels of plasma and of intake of vitamin A and several carotenoids than healthy people. The consumption of cooling foods was positively associated with the total consumption of vegetables and fruits which affect the intake of several antioxidative nutrients.
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Reid, Mary Alexandra. "Plasma Pattern Recognition Receptors of Walleye (Sander vitreus M.) with an Emphasis on Mannose-binding Lectin-Like Protein and Viral Hemorrhagic Septicemia Virus." Thesis, 2012. http://hdl.handle.net/10214/3858.
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Walleye (Sander vitreus M.) are valuable in commercial and recreational fisheries
and are affected by bacterial, fungal and viral disease. Pattern recognition receptors
(PRRs) are germline-encoded and constitutively expressed and bind non-self or altered-self for immune recognition. Walleye were hypothesised to have circulating PRRs that
were capable of binding diverse pathogens. These PRRs were hypothesised to increase
with infection, be distributed in immunologically relevant tissues and to be strain and age specific. PRR binding was measured by affinity chromatography, plasma binding assays,SDS-PAGE, Western blots, ELISA, PCR, and immunohistochemistry. ELISA and affinity
chromatography assays were developed in rainbow trout (Oncorhynchus mykiss) with
known PRRs. Trout ladderlectin was confirmed as a PRR binding viral hemorrhagic
septicemia virus (VHSV). These techniques were adapted to walleye using Flavobacterium columnare, chitin, VHSV and Sepharose resin. A 22 kDa protein bound to F. columnare, a 17 kDa protein bound to chitin and a 34 kDa protein bound to VHSV were identified as similar to bass apolipoprotein, carp C3 and rainbow trout intelectin, respectively. PCR and 3'-RACE-PCR were used to generate nucleotide sequence to confirm identity of walleye apolipoprotein and mannose-binding lectin (MBL)-like protein from the intelectin-like sequence. Two rabbit polyclonal antibodies were raised to 34 and 67 kDa MBL amino acid sequences and used to verify MBL-like protein as a PRR for VHSV. Healthy walleye MBL-like protein plasma concentration was 7.5 ng/ml. Significant differences were found between geographically distant strains of walleye. An ELISA demonstrated that MBL-like protein had significant differences in binding affinity between multiple strains of VHSV and different viruses found in Ontario. MBL-like protein plasma levels increased with initial infection of naïve fish with waterborne and IP VHSV (107 pfu) but did not change with IP reinfection. Previous infection with VHSV significantly decreased walleye mortality. IHC of walleye shows MBL-like protein is distributed in epithelial surfaces, primarily skin, oropharynx, gill, gastrointestinal system, renal nephrons, connective tissue of gonads and plasma. There was no qualitative difference in MBL-like protein tissue distribution in healthy and VHSV-infected walleye. This is the first evidence for fish lectins binding viruses.
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"Analysis of the Fragmentation Patterns of DNA in Plasma." 2016. http://repository.lib.cuhk.edu.hk/en/item/cuhk-1292187.
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基於血液循環脫氧核糖核酸（DNA)的發現，已經在無創性產前診斷技術(NIPT)檢測及癌症研究帶來重大的轉變。科技的快速發展推出了不少高通量平台作為循環DNA的分析。縱使如此，對於循環DNA的本質及特性是還有很多未被完全了解的部份。因此，研究循環DNA的特性有望提升現時測試的水平以及開拓新的研究領域。<br>論文的第一部分會著重於評估微滴式數字聚合酶連鎖反應（droplet digital PCR (ddPCR) )的精準度。作為高通量的數字PCR平台可以達到核酸的絕對定閏分析，這平台在臨床研究上的用處很大，亦有越來越多的檢測在這平台上運行。但是卻從沒有人對於這嶄新的平台的精準度進行任何系統性的評估。精準度在循環DNA的研究特別重要。因為循環DNA本來就比細胞內的DNA破碎及低濃度。再者，許多的檢測的目的是少眾DNA,如帶有突變核酸的DNA，因為該平台的精準度對測試有重大影響。<br>除了平台系統帶來的因素，化驗測試本身的設計亦非常重要。為了減低在雙重PCR中兩條擴增子受到序列不同的影響，我設計了兩對序列有高相似度的引物，希望可以設計出更多不同的檢測。但出乎意料之外，兩條擴增子在在細胞內的DNA得到的核酸是數量是一樣的。可是，當對循環DNA進行定量時，卻發現結果相當不平衡。這引起了我的猜測關於這其實的循環DNA的特性之一。<br>因此，論文的後半部分，為了集中研究了這種非隨機的模型，需要一個參數去形容循環DNA是如何受影響。而這參數的變化就如波浪一樣，有高有低，而且它的週期性跟核小體大小分怖相似。因此，從全基因組的結果，循環DNA的碎片化并非隨機發生。<br>基於這些結果，再推進一步的猜想是核小體的DNA上有組蛋白可以保護DNA不受酶的攻擊，保持完整。但如果一些基因是不受核小體保護，會否因而更被消化。因此如果可以了解核小體的排列，再配合血漿DNA的測序，就有機會了解更多關於循環DNA的本質跟產生原理。<br>綜合以上，這論文有系統地評估了微滴式數字聚合酶連鎖反應的精確度，更闡述了一些未被描述過的循環基因特性。<br>The discovery of circulating cell-free DNA has opened up new possibilities for non-invasive diagnostics. The advent of high-throughput platforms for circulating DNA analysis has spurred rapid development in cell-free research. However, much remains unknown about the nature of plasma DNA. Using cutting-edge technology, this thesis addresses the characteristics and nature of plasma DNA.<br>One of the most rapidly growing platforms for circulating DNA analysis, droplet digital PCR (ddPCR) is a modern high-throughput digital PCR platform permitting absolute quantification of DNA molecules. However, whether the platform’s precision is high enough for precise minor allele quantification remains unproven. Therefore, in Chapter 4, I evaluated its analytical performance and demonstrated the conditions needed for precise measurement.<br>Not only the platform but also the sequence context of ddPCR is a parameter affecting the assay performance. In Chapter 5, I demonstrated the use of paralogous sequences for ddPCR assay, expecting the high sequence similarities to minimise the PCR bias. However, an imbalance between amplicons quantity still appears in some samples. Surprisingly, this skewness of ddPCR ratio appears in cell-free but not genomic DNA.<br>Suspecting this might be due to the fragmentation patterns of plasma DNA, I systematically analysed high-depth plasma DNA sequencing data in Chapter 6. Based on the data, I developed a parameter, intact probability, as a measure of the degree of fragmentation, representing the proportion of amplifiable DNA in certain regions. This genome-wide map of intact probability showed uneven genome coverage, with a wave-like pattern and a periodicity of 200 bp across the entire genome. These results suggest the fragmentation in plasma DNA is non-random. Also, the algorithm allows for the design of precise plasma DNA ddPCR assay.<br>The intact probability results in Chapter 6 allowed me to further hypothesize that the fragmentation pattern of plasma DNA relates to chromatin structure. Regions with high intact probabilities are more protected by histones and hence have more amplifiable DNA in circulation. Since chromatin structure relates to tissue specificity, in Chapter 7, I explored the relationship between nucleosome profiles of maternal buffy coat and fetal placental tissues with the fragmentation of plasma DNA. I used the Assay for Transposase-Accessible Chromatin sequencing (ATAC-seq) to obtain the high-resolution genome-wide chromatin profiles of the two tissues. Incorporating the open chromatin profiling of different tissues with very deep plasma DNA sequencing, I found that open chromatin regions marked by ATAC-seq are more under-represented in plasma DNA and shorter in size. In Chapter 7, I characterized the non-random fragmentation patterns of plasma DNA.<br>Besides nuclear DNA fragmentation patterns, I examined the fragmentation of the non-nuclear genome, mitochondrial DNA, which appears in plasma (Chapter 8). I explored the fragmentation patterns in high resolution and noted the positive correlation bet<br>Wong, In Chun.<br>Thesis Ph.D. Chinese University of Hong Kong 2016.<br>Includes bibliographical references (leaves ).<br>Abstracts also in Chinese.<br>Title from PDF title page (viewed on …).<br>Detailed summary in vernacular field only.<br>Detailed summary in vernacular field only.<br>Detailed summary in vernacular field only.<br>Detailed summary in vernacular field only.<br>Detailed summary in vernacular field only.<br>Detailed summary in vernacular field only.
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Pai, Shih-feng, and 白士峰. "Fabrication of Patterned Sapphire Substrates by High-Density-Plasma Etching." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/20540110453550035296.
Full textAbstract:
碩士<br>國立中興大學<br>材料工程學研究所<br>92<br>III-nitride compound semiconductors are recognized to be the key materials for optoelectronic devices, such as short-wavelength light-emitting diodes (LEDs) and laser diodes. In the conventional epitaxial process for GaN LEDs, threading dislocations are the most common defects, which make the carrier releasing energy without luminescence as a result of nonradiative recombination effect. The reduction of threading dislocations is very important if one wants to fabricate high-efficiency GaN LEDs. Recently, the patterned sapphire substrate was confirmed to be an efficient method to reduce the threading dislocations and to enhance the scattering the emission light from the active layer. Thus the external quantum efficiency of the GaN LED was improved.
In this thesis, the pattern etching process for the sapphire wafer by an inductively-coupled-plasma (ICP) etcher was described. The etch characteristics were investigated by varying the etching parameters, such as gas combination of Cl2/BCl3/Ar, chamber pressure, ICP power, and DC-bias voltage. The increase of BCl3 content (up to 66.7%) in the Cl2/BCl3 gas mixture increases the etch rate and improves the etch selectivity over Ni. In our experiments, the etch rate of sapphire can increase from 35 to 280 nm/min with a surface roughness from 0.2 to 1.9 nm, and the etch profile from 60 to 79°. The etch selectivity over Ni can reach above 6 which is higher than the other mask materials (SiO2 or Cu). However, the SiO2 mask can offer the lower taper angle from 24 to 35° after ICP etching due to the faster etch rate of the SiO2 side wall. Thus one can utilize a suitable mask material to achieve the etching rate, taper angle, and roughness which are desirable for patterned sapphire substrates.