Dissertations / Theses on the topic 'Draw materials'
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Jianfeng, Wang. "Principles of the draw-bend springback." The Ohio State University, 2004. http://rave.ohiolink.edu/etdc/view?acc_num=osu1080237228.
Full textWang, Jianfeng. "Principles of the draw-bend springback test." Columbus, Ohio : Ohio State University, 2004. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1080227128.
Full textTitle from first page of PDF file. Document formatted into pages; contains xvii, 167 p.; also includes graphics (some col.). Includes abstract and vita. Advisor: Robert H. Wagoner, Dept. of Materials Science and Engineering. Includes bibliographical references (p. 158-167).
Edrington, Sarah. "THE LIMITS & EFFECTS OF DRAW ON PROPERTIES AND MORPHOLOGY OF PAN-BASED PRECURSOR AND THE RESULTANT CARBON FIBERS." UKnowledge, 2017. http://uknowledge.uky.edu/me_etds/89.
Full textGuilleaume, Christina, Alexander Brosius, and Ali Mousavi. "Investigation of Alternative Polymer Composite Materials for Forming Applications." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2018. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-235022.
Full textThis paper presents the investigation of polymer concrete drawing tools for deep drawing operations. The goal of using polymer concrete as an alternative material is a rapid tooling process at relatively low initial tools costs that is suitable for small batch production. Similar concepts based on hydraulic concrete and polymer composites have shown that the surface tri-bology and consequently wear is the main limiting factor. Therefore, this paper focusses on the results of strip draw-bending tests with different polymer concrete mixtures. The friction coefficient is calculated and compared to a steel tool
Garapati, Sriharsha. "Analytical and Numerical Modeling of Assembly Procedures of Steel Fulcra of Bascule Bridges." Scholar Commons, 2013. http://scholarcommons.usf.edu/etd/4490.
Full textChung, Kyu-Ha. "Composite compliant coatings for drag reduction utilizing low modulus high damping silicone rubber." Thesis, Massachusetts Institute of Technology, 1985. http://hdl.handle.net/1721.1/15263.
Full textMICROFICHE COPY AVAILABLE IN ARCHIVES AND SCIENCE.
Includes bibliographical references.
by Kyu-Ha Chung.
Ph.D.
Elsayad, Kareem. "Understanding the insulating phases of disordered materials through crosstalk and Coulomb drag experiments." [Bloomington, Ind.] : Indiana University, 2007. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3290773.
Full textTitle from dissertation home page (viewed May 28, 2008). Source: Dissertation Abstracts International, Volume: 68-11, Section: B, page: 7391. Adviser: John P. Carini.
Grena, Benjamin (Benjamin Jean-Baptiste). "Phase separation in thermally-drawn fibers: From porous domains to structured Si-Ge spheres." Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/111324.
Full textCataloged from PDF version of thesis.
Includes bibliographical references (pages 149-160).
The preform-to-fiber thermal drawing method is a versatile process that allows the fabrication of polymer or glass-based fibers with complex multimaterial internal structures, which grant them functions ranging from optical transmission to chemical detection. However, while a wide range of materials have been successfully drawn in various phases - such as metals, semiconductors, and ferroelectric polymers - the overall structure of the fiber is typically axially-invariant and the incorporation of heterogeneous materials with isotropic microstructures such as porous domains has remained elusive thus far. In this thesis we investigate the use of in-fiber phase separation as a means to control the microstructure of different components within thermally-drawn fibers. In particular we propose a novel method based on controlled phase separation of a polymer solution that we use to embed isotropically porous polymeric domains inside multimaterial fibers. We achieve this by thermal-drawing a hollow polymer preform filled with a liquid polymer solution in its core. We later apply this method to the fabrication and characterization of scaffolds for neural regeneration. In addition, we show that the same principle can also be used to draw a functional lithium-ion fiber battery; a fiber device capable of electrochemical energy storage. Finally, we demonstrate how to produce structured Si-Ge spheres encapsulated within a silica cladding by inducing capillary breakup of a continuous Si-Ge core fiber in a strong axial thermal gradient. The thermal gradient causes a "kinetic phase separation" of the alloy, leading to structured Janus particles.
by Benjamin Grena.
Ph. D.
Fekkai, Zakia. "Dimensional stability of biaxially drawn PET : effects of processing and material composition." Thesis, Loughborough University, 1991. https://dspace.lboro.ac.uk/2134/32890.
Full textGupta, Anurag. "The artificially blunted leading edge concept for aerothermodynamic performance enhancement." Diss., Georgia Institute of Technology, 1999. http://hdl.handle.net/1853/12442.
Full textBechert, Mathias [Verfasser], Dirk W. [Gutachter] Schubert, and Benoit [Gutachter] Scheid. "Influence of Process and Material Parameters on the Draw Resonance Instability / Mathias Bechert ; Gutachter: Dirk W. Schubert, Benoit Scheid." Erlangen : FAU University Press, 2017. http://d-nb.info/114323202X/34.
Full textGispert, Pellicer Esther. "El cinema com a recurs i matèria d'estudi: l'experiència de Drac Màgic." Doctoral thesis, Universitat de Girona, 1996. http://hdl.handle.net/10803/7979.
Full textLa segona part de la tesi està dedicada íntegrament a l'estudi de l'experiència d'una cooperativa de Barcelona, anomenada Drac Màgic, que des de fa vint-i-cinc anys treballa en l'aplicació del cinema en l'àmbit de l'educació formal i en la formació permanent del professorat. L'anàlisi d'aquesta proposta, ens permet concretar amb un exemple pràctic, que és molt proper a la nostra realitat immediata, es aspectes teòrics que hem presentat en la primera part de la tesi. Per altra banda, l'estudi d'aquesta experiència pretén ser un punt de referència a l'hora de realitzar la proposta pràctica d'integració del cinema en els plantejaments educatius, que realitzem a la quarta part de la tesi.
En la tercera part de la tesi, hem investigat en el marc legal que configura les possibilitat i els límits que se'ls hi plantegen als professors que estan interessats en introduir els mitjans de comunicació, en general, i el cinema, en particular, en les seves pràctiques educatives. Així, doncs, per conèixer el nivell de compromís que les institucions públiques adopten per potenciar la introducció dels mitjans de comunicació en general, i del cinema, en particular, a les escoles, hem investigat en el marc legal que regula actualment el funcionament dels centres escolars i que es coneix amb el nom de Reforma educativa i també hem volgut conèixer els principals objectius i les activitats que desenvolupen dues iniciatives institucionals El Programa de Noves Tecnologies de la Informació i de la Comunicació del Ministeri d'Educació i Ciència espanyol i el Programa de Mitjans Audiovisuals del Departament d'Ensenyament de la Generalitat de Catalunya.
En la quarta part de la tesi, hem dissenyat una proposta pràctica per introduir el cinema a les escoles del nostres país, que s'ha concretat en l'elaboració d'un crèdit variable sobre cinema destinat als alumnes que cursen l'Educació Secundària Obligatòria.
The thesis entitled "The Cinema as a means and subject of study: the experience of Drac Màgic" consist of four clearly differentiated, but complementary, parts which show the intention to direct the introduction of the cinema into the area of education. The main object of the first part of the thesis is to create a theoretic framework where research and the opinion of different authors meet. These authors, from the communication field or specialists in the education field, have asked themselves, from the point of view of their specific areas of study, about aspects related to the presence of the media in general and also about the incidence of the cinema, in particular, in our society and in people. In my opinion, an educator interested in the possibility of introducing the cinema into educational practice must dispel the main doubts which are formed by the most basic questions, which are as follows: what is the cinema, why introduce it, which is to be introduced and how introduce it.
The second part of the thesis is totally dedicated to the study of the experience of a group from Barcelona called Drac Màgic, which has been working for twenty-five years on the use of cinema in the area of formal education and teacher training. The analysis of this proposal allows us to pinpoint the theoretical aspects than we have presented in the first part of the thesis with a practical example which is very close to our immediate reality. On the other hand, the study of this experience is intended to be a point of reference while at the same time carrying out the practical proposal for the integration of the cinema in the educational expositions that we make in the fourth part of the thesis.
In the third part of the thesis we have looked into the legal framework which forms the possibilities and the limits presented to the teachers who are interested in introducing the media, in general, and specially the cinema in their practical teaching. In order to know the commitment that the public institutions adopt to reinforce the introduction into schools of the media in general and specially the cinema, we have looked into the legal framework than regulates the function of schools at the present time and is know as Educational Reform (Reforma educativa) and we have also wished to know the main objectives and activities than are being developed by two institutional bodies The Programme for New Technologies of Information and Communication (Programa de Noves Tecnologies de la Informació i de la Comunicació) by the Spanish Ministry of Education and Science and the Programme of Audiovisual Media (Programa de Mitjans Audiovisuals) by the Department of Education of the Generalitat de Catalunya.
In the fourth part of the thesis we have drawn up a practical proposal on how to introduce the cinema into the schools of our country, which is to develop a variable credit about cinema for the students who are studding the Compulsory Secondary Education.
Liu, Ning. "Microstructure and mechanical properties of cold drawn steel wires." Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2012. https://ro.ecu.edu.au/theses/512.
Full textGass, Evan M. "Anisotropy in Drawn and Annealed Copper Tube." Ohio University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou153503217197025.
Full textMorais, José Eduardo Vasconcelos de. "Estudo experimental e numérico de antena ressoadora dielétrica (DRA) baseada em Sr2CoNbO6." reponame:Repositório Institucional da UFC, 2014. http://www.repositorio.ufc.br/handle/riufc/10843.
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The purpose of this work was to study the dielectric properties in Radio Frequency ( RF) and microwave compound Sr 2 CoNbO 6 ( SCNO ) adding with titanium oxide ( TiO 2 ) in percentages ranging from 15 % to 22 % by mass. The SCNO is a double perovskite , which was prepared by the met hod of solid state reaction . The samples were characterized structurally by x - ray diffraction (XRD ). The method used to obtain the desired phase was by Rietveld refinement , showed that formant type cubic symmetry pm3m. The dielectric properties : dielectr ic constant ( ε ' ) and dielectric loss ( tg δ ) were measured at room temperature in the frequency range of 100 KHz to 2GHz , showed that the permittivity decreases with frequency below 50 MHz the dielectric constant is very high and above 1GHz appears low. The picnometry performed showed that the relative densities were all above 9 0 %. For the study of microwave stay full it was applied the method of Hak ki Coleman, which showed growth of the dielectric permittivity with increasing concentration of TiO 2 ( 14 - 52) a nd loss tangent ranging from 10 - 1 - 10 - 4 . The temperature coefficient of resonant frequency ( τ f) showed that SCNO τ f has a negative ( - 634ppm/oC) . With the addition of TiO 2 τ f showed positive results. The numerical simulation of the dielectric res onator antenna ( DRA ) based on SCNO and added with TiO 2 was performed with HFSS ® and the results were q uite consistent with the experiments . The low gain and a small presented to the SCNO efficiency was improved substantially with the addition of TiO 2 . These properties can be improved with a proposal for a new geometry for dielectric res o nator antenna ( D RA ) and with addition of TiO 2 in new percentages for analysis of dielectric properties and parameters of antennas
Temos como objetivo neste trabalho estudar as propriedades dielétricas em rádio frequência (RF) e micro-ondas do composto Sr2CoNbO6 (SCNO) adicionando com o óxido de titânio (TiO2) em porcentagens variando de 15% a 22% em massa. O SCNO é uma perovskita dupla, que foi preparado através do método de reação do estado sólido. As amostras foram caracterizadas estruturalmente através da difração de raio – X (DRX). O método utilizado para obtenção da fase desejada foi realizada através do refinamento de Rietveld, que mostrou estrutura de simetria cúbica do tipo pm3m. As propriedades dielétricas: constante dielétrica (ε’) e fator de perda dielétrica (tgδ) foram medidas à temperatura ambiente na faixa de frequência de 100KHz a 2GHz e mostraram que a permissividade diminui com a frequência. Abaixo de 50MHz a constante dielétrica se apresenta alta e acima de 1GHz se apresenta baixa. A picnometria realizada mostrou que as densidades relativas ficaram todas acima de 80%. Para que o estudo de micro-ondas ficasse completo aplicamos o método de Hakki Coleman, que mostrou crescimento da permissividade dielétrica com o aumento da concentração de TiO2 (14 – 52)e perdas dielétricas variando de 10-2 - 10-4 . O coeficiente de temperatura da frequência de ressonância (τf) mostrou que o SCNO apresenta τf negativo (-634ppm/oC). Com a adição do TiO2 o τf passou a apresentar valores positivos. A simulação numérica de uma antena ressoadora dielétrica (DRA) baseada no SCNO e adicionada com TiO2 foi realizada através do software HFSS® e os resultados se apresentaram bastante concordantes com os experimentos. O baixo ganho e uma pequena eficiência apresentada para o SCNO puro foi melhorado substancialmente com a adição do TiO2. Estas propriedades podem ser melhoradas com uma proposta de uma nova geometria para a (DRA) e com adição do TiO2 em novas porcentagens para análises de propriedades dielétricas e parâmetros de antenas.
Jörgensdotter, Freja. "Bli en miljönär med klimatsmarta drag i vardagen : En informationsbroschyr med fokus på miljö, konsumtion och material." Thesis, Linnéuniversitetet, Institutionen för design (DE), 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-63782.
Full textKalagotla, Dilip. "Modeling Particle Drag in Accelerating Flows with Implications for SBLI in PIV - A Numerical Analysis." University of Cincinnati / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1523630352322552.
Full textKumbier, Alana. "Ephemeral Material: Developing a Critical Archival Practice." Columbus, Ohio : Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1236198205.
Full textFreese, Samuel Henrique. "Estudo da capacidade de proteção anti-corrosiva de óleos de processo em materiais trefilados." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2012. http://hdl.handle.net/10183/75758.
Full textDrawn carbon steel has excellent mechanical proprieties, dimensional stability and good surface quality as characteristics. But, to supply this material, a necessary care is the temporary protection against atmospheric corrosion, which can be defined as a process resulting from chemical and / or electrochemical reactions, in which metals and alloys deteriorate when subjected to climate action. To avoid / retard this process, usually it’s used an application of an oil coat that protects the base material. Trying to understand the protective capacity of oils used in drawn materials, 3 products used in polishing process and 3 applied as final protection were selected. Samples tested in humid chamber with different combinations of products were evaluated, showing that the protective capacity of oils used as final protection is directly related with their density, a relation that is not presented in polishing oils. With these results we can forecast the protective capacity of oils used as final protection employing its density as reference, because of the linear relation, having another factors, like the type of polishing oil, affecting the curve equation constant.
Rubenking, Samuel Kim. "Dual Mode Macro Fiber Composite-Actuated Morphing Tip Feathers for Controlling Small Unmanned Aircraft." Thesis, Virginia Tech, 2017. http://hdl.handle.net/10919/78433.
Full textMaster of Science
Ma, Ning. "Theory and modeling of microstructural evolution in polycrystalline materials solute segregation, grain growth and phase transformation /." Connect to this title online, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1111774761.
Full textTitle from first page of PDF file. Document formatted into pages; contains xvii, 181 p.; also includes graphics (some col.). Includes bibliographical references (p. 168-181). Available online via OhioLINK's ETD Center
Soroudi, Azadeh. "Melt Spun Electro-Conductive Polymer Composite Fibers." Doctoral thesis, Högskolan i Borås, Institutionen Ingenjörshögskolan, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-3590.
Full textThesis to be defended in public on Friday, May 20, 2011 at 10.00 at KC-salen, Kemigården 4, Göteborg, for the degree of Doctor of Philosophy.
Narvaez, Javier Artemio. "Evaluation of Alumina Nanofluids and Surfactant Drag Reducing Solutions to Improve Heat Transfer for Aircraft Cooling Systems." University of Dayton / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=dayton154479500350447.
Full textEgunov, Aleksandr. "Strain-engineering of thin polymer films : a novel route for the development of functional materials and microfluidic devices." Thesis, Mulhouse, 2015. http://www.theses.fr/2015MULH1619.
Full textTwo systems of stress creation in the polymer films were developed, each based on the swelling gradient in the direction normal to the film. This swelling may be caused either by the presence of a crosslinking density gradient in the direction normal to the surface (poly (4-vinylpyridine film) crosslinked by UV or in the thermally or ionically crosslinked chitosan films; or by asymmetric penetration of solvent vapor in the film (here polydimethylsiloxane surface-oxidized). A third self-rolling polymeric system has also been realized by the creation of a permanent strain in the polydimethylsiloxane film by selective extraction of a non-cross-linked additive, silicone oil. A theoretical model of self-rolling process based on the linear theory of elasticity has been proposed
Laffargue, Johann. "Etude et modélisation des instabilités du procédé de soufflage de gaine." Phd thesis, École Nationale Supérieure des Mines de Paris, 2003. http://pastel.archives-ouvertes.fr/pastel-00000432.
Full textStrandlund, Henrik. "Simulation of diffusional processes in alloys : techniques and applications." Doctoral thesis, Stockholm, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-399.
Full textSung, Ji-Hyun. "The Causes of “Shear Fracture” of Dual-Phase Steels." The Ohio State University, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=osu1268039436.
Full textBindas, Erica Bindas. "EFFECT OF TEMPERATURE, STRAIN RATE, AND AXIAL STRAIN ON DIRECT POWDER FORGED ALUMINUM-SILICON CARBIDE METAL MATRIX COMPOSITES." Case Western Reserve University School of Graduate Studies / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=case1530871866585058.
Full textMachala, Petr. "Návrh potrubního řetězového dopravníku." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2020. http://www.nusl.cz/ntk/nusl-416427.
Full textAbbasi, Baharanchi Ahmadreza. "Development of a Two-Fluid Drag Law for Clustered Particles Using Direct Numerical Simulation and Validation through Experiments." FIU Digital Commons, 2015. http://digitalcommons.fiu.edu/etd/2489.
Full textTevissen, Etienne. "Méthodologie d'étude et modélisation du transport de solutes en milieux poreux naturels : application à la migration du chrome dans la nappe alluviale du Drac (Isère)." Vandoeuvre-les-Nancy, INPL, 1993. http://www.theses.fr/1993INPL089N.
Full textWithrow, Travis P. "Computational Modeling of Atom Probe Tomography." The Ohio State University, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=osu1525763934302517.
Full textZuanetti, Bryan. "Plate Impact Experiments for Studying the Dynamic Response of Commercial-Purity Aluminum at Temperatures Approaching Melt." Case Western Reserve University School of Graduate Studies / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=case1557132337419911.
Full textAsp, Grönhagen Klara. "Phase-field modeling of surface-energy driven processes." Doctoral thesis, KTH, Metallografi, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-11036.
Full textQC 20100622
Bessa, Kleiber Lima de. "Redução de arrasto por adição de polímeros em escoamento pulsátil laminar e turbulento em leitos arteriais caudais de ratos normotensos e hipertensos e tubos rígidos." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/3/3150/tde-12092008-140246/.
Full textIn this work, the drag reduction was analyzed in two benches located at Laboratory of Fluid Mechanics at Polytechnic School (EPUSP) and at Laboratory of Vascular Physiology at Institute of Biomedical Science (ICB-USP). The drag reduction was investigated for the following polymers: polyacrilamide 1822S and 1340S, polyethylene glycol (PEG4000) and polyethylene oxide (Polyox WSR-301). The rheological behavior of polymeric solutions of polyacrilamide and PEG4000 was acquired experimentally; while it was obtained from the literature for Polyox WSR-301. All of these polymers were used in the hydrodynamic simulator, but only PEG4000 was employed in the tails arterial bed from normotensive (Wistar) and spontaneously hypertensive rats (SHR) at ICB-1. In the hydrodynamic simulator, the drag reduction was analyzed in laminar and turbulent pulsatile flow, in the range varying between 2300 and 13700, with polymeric concentrations between 5 and 100 ppm, but for PEG4000, concentration has reached 5000 ppm. On the other hand, in the tail arterial beds, the drag reduction was analyzed for laminar flow, in the range between 100 and 700, with polymeric concentration of 5000 ppm. In addition, it was studied in the presence and absence of endothelial cells. Computational simulation using the finite volume method (Fluent) was performed using data obtained from ICB-1 in order to analyze the wall shear stress distribution along of wall vessel both in the presence and absence of endothelial cells and PEG4000, considering the rigid walls. Polyacrilamide 1822S and 1340S as well as PEG4000 showed behavior of Newtonian fluid in the following concentrations: 5 and 10 ppm and 5000 ppm, respectively. On the other hand, for polyacrilamides, concentrations higher than 10 ppm showed behaviour of non- Newtonian fluids. According to the literature, the Polyox WSR-301 behaved as a Newtonian fluid in all concentrations used in this work. At EPUSP\'s bench, while PEG4000 did not show drag reduction for any polymeric concentration analyzed, this phenomenon could be seen for polyacrilamides and Polyox WSR-301, being dependent on Reynolds number as well as polymeric concentration. More important, Polyox WSR- 301 showed to be the most efficient drag reducer of them. Interestingly, in the assays employing the tail arterial beds, PEG4000 showed drag reduction in the concentration of 5000 ppm and it was increased by the presence of the endothelial cells. Thus, Polyox WSR-301 seems to be more efficient to promote drag reduction in the rigid tubes. On the other hand, while PEG4000 did not show drag reduction at EPUSP\'s bench, it was a good drag reducer in the tail arterial beds, being intensified by the action of endothelial cells.
Marou, Alzouma Ousseini. "Durabilité tribologique de matériaux pour insert de dents de tunnelier." Thesis, Ecully, Ecole centrale de Lyon, 2015. http://www.theses.fr/2015ECDL0042.
Full textThe frequency of maintenance operations during the excavation of the ground by the tunnel boring machines (TBM) is problematic for civil engineering companies. These maintenance operations provoke expensive timeouts and they bring in excavation operators in risky hyperbaric work conditions. One of the reasons which leads to the numerous human interventions for the maintenance is the damage of drag bits located on the cutting wheel of the TBM. These drag bits undergo wear due to the abrasiveness of the various media they meet. The purpose of this thesis is to contribute to increase by 20 % at least the lifetime of the materials of the dag bits, in order to reduce the various maintenance operations which expose the operators to important risks. To achieve this goal, the investigations led in this work concerned several axes. At first, an expertise is led to identify the wear modes prevailing on the carbide inserts located on the drag bits; then, new materials with enhanced mechanical properties and optimized microstructures, developed in the framework of the European project NeTTUN, are characterized on representative lab testing devices. These tests allowed us to understand well the wear mechanisms of the newly developed grades of tungsten carbides. The results of this work can lead to new strategies for the selection of materials to reinforce the drag bits
Vieluf, Maik. "Hochauflösende Rutherford-Streuspektrometrie zur Untersuchung von ZrO2-Schichtwachstum im Anfangsstadium." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2010. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-38113.
Full textThis thesis originated from a cooperation between Research Center Dresden-Rossendorf and Qimonda Dresden GmbH & Co. OHG. By means of High Resolution Rutherford Backscattering Spectrometry (HR-RBS) the diffusion behaviour and layer growth of ZrO2 on SiO2 and TiN in the initial regime were investigated. The analysis of concentration profiles in ultrathin layers and interfaces was the focus of this work, made possible by the excellent depth resolution of less than 0.3 nm near the surface. For the first time a two-dimensional position sensitive semiconductor detector was implemented and characterized in the setup of the HR-RBS for the improvement of the quality of the measurement results. Furthermore, a measurement procedure was put into operation that allowed the reduction of ion induced damage. Through the optimization of the experimental conditions and the development of a program package for the support of the analyst, an efficient measurement procedure could be routinely ensured. At the time of a binary collision between the incident ion and the target element with a small impact factor, the charge state changes frequently, especially due to the abruptly decreasing ion velocity of the projectile and the overlapping of the electron clouds. For HR-RBS with an energy-separating dipole magnet, the charge state distribution of the scattered ions must be known for the interpretation of the measured spectra. For the first time a significant dependence of the charge state distribution of the scattered C ions on the layer thickness as well as atomic number of the detected target elements, here from the fourth subgroup, was emonstrated. This new knowledge allowed systematic investigations of the ZrO2 layer growth in the initial regime. The ZrO2 layers were produced by means of the atomic layer deposition (ALD). Based on the evidence for agglomeration of ZrO2 on SiO2 a method was introduced, which takes local thickness variations into account during the simulation of the HR-RBS spectra. An accurate statement about the ZrO2/SiO2 interface was possible due to the extraction of the thickness variation by the atomic force microscopy (AFM). The boundary surface is sharp except for a small intermediate ZrSiO4 layer and no diffusion of Zr atoms in SiO2 could be detected. A quite different behaviour could be derived from high resolution spectra for the growth of ZrO2 on TiN. Measurements of the surface topography of the TiN layer revealed non negligible values for the surface roughness. A program was developed to capture the influence of the surface roughness on the shape of the high resolution spectrum. This software uses AFM measurements to extract an energy distribution from calculated path length differences for ions scattered at the sample surface. Diffusion of Zr into polycrystalline TiN was demonstrated for the first time taking into account the effect of the surface roughness on the shape of the spectra. This observation indicates that already after the first ALD reaction cycle a small part of the deposited Zr atoms diffuses into the TiN layer up to a depth of 3 nm. Such preliminary results suggest grain boundary diffusion
Rabiee, Hesamoddin. "Gas responsive microgels as novel draw agents for forward osmosis desalination." Thesis, 2018. http://hdl.handle.net/2440/114507.
Full textThesis (M.Phil.) (Research by Publication) -- University of Adelaide, School of Chemical Engineering, 2018.
"Forward Osmosis Desalination Using Thermoresponsive Hydrogels as Draw Agents; An Experimental Study." Master's thesis, 2019. http://hdl.handle.net/2286/R.I.53871.
Full textDissertation/Thesis
Masters Thesis Mechanical Engineering 2019
Yu, Da-Wei David. "Turbulent pipe flow drag reduction with narrow distribution polystyrene materials : a test of drag reduction theories." Thesis, 1998. http://hdl.handle.net/1957/34137.
Full textMowery, Daniel Michael. "Investigation of the structure of cold -drawn high -density polyethylene using solid-state NMR." 2002. https://scholarworks.umass.edu/dissertations/AAI3068580.
Full text"Understanding the insulating phases of disordered materials through crosstalk and Coulomb drag experiments." INDIANA UNIVERSITY, 2008. http://pqdtopen.proquest.com/#viewpdf?dispub=3290773.
Full textHoppe, Richard Peter. "Partial characterization of extruded collagen tubes with varied material deposition and orientation based on rotation rate and linear draw speed." Thesis, 2001. http://library1.njit.edu/etd/fromwebvoyage.cfm?id=njit-etd2001-019.
Full textLiang, Ting-Hua, and 梁庭華. "A Study of High Dielectric Constant Material TiO2 Deposited by Electron Beam Evaporation for DRAM Capacitors." Thesis, 1996. http://ndltd.ncl.edu.tw/handle/04098952902900584893.
Full text國立交通大學
電子研究所
84
In this work, the effects of electrode materials (W, WN, Ta, TaN, Mo, and TiN)on the leakage current of TiO2 films were studied. The optimum electrode materials for high- and low- temperature processes (800 ℃ and 400 ℃) are shown. No obvious correlation between ψms and Vcrit (voltage at 10E-6 A/ cm2)is found in our experimental results. We also discussed post-TiO2-deposition annealing effect using TaN top electrode. The effects of annealing ambient, annealing temperature, and annealing time are included. In annealing ambient effect, temperature dependence of leakage current was investigated. On the other hand, the effects of TiO2 film thickness and doping concentration of boron-doped substrate were analyzed. We have then demonstrated that rapid thermal N2O (RTN2O) annealing is the most effective method in suppressing leakage current of TiO2 films, compared with furnace O2 (FO) and rapid thermal O2 (RTO) annealing. For future studies, optimal process conditions of RTN2O annealing are required to further improve performance of TiO2 capacitors.
Tasi, M. S., and 蔡明憲. "A Study of High Dielectric Constant Material Barium Strontium Titanite (BaxSr1-xTiO3) for Giga Bit DRAM Stroage Capacitor Applications." Thesis, 1996. http://ndltd.ncl.edu.tw/handle/52288061739048398386.
Full text國立交通大學
電子研究所
84
As device dimensions are scaled down into the deep-submicron regime, the demand for small capacitor area while still maintaining a certain critical charge for DRAM capacitors become more stringent. Ta2O5 films are suitable for 256M to 1G bit DRAM application. However, higher dielectric constant materials are required for 1 Gbit DRAMs and beyond. Recently the BST (BaxSr1-xTiO3) film has attracted great attentions due to its high dielectric constant, low leakage current, TDDB over 10 years, resistance to process induced damage, good chemical and thermal stability and low dissipation factor. In this study, we present the physical and electrical properties of BST films deposited by RF magnetron sputtering. The effect of deposition temperature, the sputtering oxygen partial pressure and film thickness on the physical properties (grain size, orientation) electrical (leakage current, breakdown voltage, polarization, dielectric conatant) properties were investigated in details. In addition, a post-deposition thermal treatment by furnace annealing in N2 ambient was used to improve the electrical characteristics.
lin, mark, and 林俊賢. "A Study of Advanced DRAM Capacitor Structure with Rugged Poly-Si Electrode and High Dielectric Constant Material & Process Optimization for Improved Retention Characteristic." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/62652947292432198404.
Full text國立交通大學
電子工程系
88
Abstract The main goal of this thesis is to improve the refresh time of DRAM cell. It can be accomplished by two approaches. The first approach is to increase the storage capacitance of the cell, while the other approach is to reduce the junction leakage current of DRAM cell. For increased storage capacitance, polycrystalline silicon film with a rugged surface (i.e., rugged poly-Si) was applied. The rugged-poly was deposited by a single-wafer rapid thermal chemical vapor deposition (RTCVD) system, suitable for 12-inch wafer fabrication. In this thesis, the rugged poly-Si films have been successfully fabricated to serve as the bottom storage electrode for the stacked capacitor in dynamic random access memory cells. Our study suggests that the rugged poly-Si is actually formed by the nucleation generation on the amorphous silicon surface and subsequent crystalline growth during the annealing step following deposition. An effective surface area of approximately 2.9 times that of a conventional poly-Si film electrode is obtained. In addition, we have fabricated and studied the electrical and physical characteristics of Ta2O5 films on rapid thermal nitrided (RTN) rugged polycrystalline silicon electrodes for 256M dynamic random access memory (DRAM) application. To overcome the higher leakage current on Ta2O5 films with rugged poly-Si bottom electrodes, we have successfully employed a light oxidation on rugged poly-Si grains for improving the acute angle of surface morphology, and a post-treatment with rapid thermal nitridation of N2O on Ta2O5 films to reduce the leakage current. The successful integration of Ta2O5 film with rugged poly-Si makes it very promising for future 256M dynamic random access memory (DRAM) application. Since the retention time distribution of DRAM consists of a ‘tail distribution’ and a ‘main distribution’. Increasing the storage capacitance only improves the ‘main distribution’ of the DRAM array, but it does not change the tail distribution. Since the refresh characteristics of a DRAM array are determined by the worst-case bits represented by the ‘tail distribution’, so increasing the storage capacitance does not improve the overall refresh characteristics of the DRAM array. The ‘tail distribution’ is found to be affected by thermionic field emission (TFE) current of dislocation and stacking faults, while the ‘main distribution’ is affected by generation-recombination (G-R) current of SiO2/Si interface trapped center and H-atom trapped center. We have performed a detailed study, and found that the ‘tail distribution’ is affected by HDP, furnace oxidation, and etching profile processes. In contrast, we found that the ‘main distribution’ is strongly affected by H2 plasma treatment, and HDP trench filling processes. In this thesis, we have also performed a detailed study on how to optimize shallow trench isolation for DRAM application. The retention time distribution is improved in new DRAM generation by the new STI isolation process. However, the degree of improvement is retarded if furnace linear oxide linear is used. The control of defect generation is therefore very important to improve the retention time distribution. Finally, the effects of contact resistance of the refresh characteristics of DRAM cell were studied. Silicidation process is optimized in order to obtain low contact resistance. We found that the contact resistance of the sample with TiN capping layer is lowered by 10-15% and the nature good yield (minimum refresh time of DRAM up to 80 ms) is higher by 19.7% than those of the sample without TiN capping layer,.