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Fjeldstad, Erica, Madelene Svanbäck, and Julia Svensson. "MILJÖVÄNLIGT BYGGANDE I SKÅNE : Planering och utformning av en ekoby i Glimåkra." Thesis, Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-44779.
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The idea for this project is to design an eco-village on a property in Glimåkra in Skåne of southern Sweden, which is owned by the municipality of Östra Göinge. All of the designs in this eco-village would be built with materials that will benefit the environment and the people living there. This community would also have low energy consumption and will achieve the Miljöbyggnad Gold certification. Initially, a few eco-villages in Sweden were studied and reviewed in order to get more experience in the subject and to find inspiration. Three different types of housing units were chosen to be compared to one another to determine the two most efficient candidates. Two townhouses, two duplexes, and two villas were designed. One of each type was a simple and square compact design while the other was a more aesthetic shaped design. While reviewing the energy consumption calculations, the aesthetically designed duplex and the aesthetically designed townhouse proved to consume smaller amounts of energy than the remaining building designs. These two designs consumed smaller amounts of energy to heat the buildings and provided additional space for solar cells. The compact duplex design ended up being the only design to be able to achieve the Miljöbyggnad Gold certification, but the energy consumption of the building did not compete with the aforementioned designs. The exterior materials to be used were chosen because of their low ecological impact and how well they blend with the surroundings. The comparisons of three different types of buildings with two different designs of each helps highlight the many factors that affect the efficiency and sustainability of a building. After studying and comparing many real-world examples of energy efficient housing with these theoretical designs, the aesthetically designed duplex and townhouse will be the best performing floor plans for the eco-village in Glimåkra, Skåne.Detta examensarbete har gått ut på att planera en ekoby i Skåne. En situationsplan innehållande radhus och parhus har tagits fram med diverse vägar, grönska och gemensamma byggnader. Arbetets övergripande syfte är att uppmärksamma ekobyar och dess miljövänliga ekohus. Det är beräkningar, modellering, extern och intern handledning samt diskussioner kring energi, miljöbyggnad och estetik som genomsyrat arbetet. För att nå ett resultat dras kopplingar från tidigare forskning och publiceringar med detta arbete. Litteraturstudien innehåller certifieringssystemet Miljöbyggnad, där betygskriterierna för Guld är det som arbetet har strävat mot för byggnaderna som modellerades. I Miljöbyggnad finns även nivåerna Brons och Silver, men om någon av indikatorerna ger nivå Brons är det inte möjligt att uppnå Guld som slutgiltig nivå. En av två studerade fasadmaterial valdes till byggnaderna i ekobyn och trä valdes på grund av dess fördelar och användningsgrad i området. Den uppvärmningskälla som studerades var pelletspanna och vid valet av elkälla genomfördes en kritisk granskning av solceller samt en mer grundläggande faktainsamling av direktverkande el. Genom platsbesök, ritningar och kartor samt diskussion och revidering modellerades två utformningar av parhus, radhus och villa. Det blev tre kompakta byggnader och tre mer estetiskt utformade och dessa modellerades i Autodesk Revit. Beräkningar genomfördes både manuellt och digitalt och hjälpmedel som formler, tabeller och antagna värden användes. Parhus Estetisk och Radhus Estetisk valdes ut för att placeras i ekobyn. Dessa valdes ut på grund av dess energiförbrukning, antal bostäder och dess estetik. Parhus Estetisk på 113m² och Radhus Estetisk på 114m² hade en total energianvändning per år på 10 500 kWh respektive 10 100 kWh, där ingår uppvärmning, tappvarmvatten och hushållsel. Det får plats 20 bostäder och 80 personer för den valda situationsplanen. Utifrån beräkning och simulering resulterade parhuset och radhuset i den slutgiltiga nivån Silver. Slutsatserna av detta arbete var att det var svårare än tänkt att uppfylla betygskriterierna för Guld i certifieringen Miljöbyggnad, endast Parhus Kompakt nådde nivån Guld. De valda byggnaderna i ekobyn var de bästa alternativen och en övergripande slutsats var att arbetet blev mer som ett förarbete som måste tas vid och utvecklas.
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Tate, William R. "Full-duplex underwater networking." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2003. http://library.nps.navy.mil/uhtbin/hyperion-image/03sep%5FTate.pdf.
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Chen, Lu. "Full Duplex Relay Clusters." The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1562411023502331.
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Almradi, Ahmed Mohamed Ahmed. "Design and analysis of MIMO cooperative relaying systems." Thesis, University of Manchester, 2017. https://www.research.manchester.ac.uk/portal/en/theses/design-and-analysis-of-mimo-cooperative-relaying-systems(07eae61a-0990-41a6-a988-46652e2cced0).html.
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Cooperative relaying techniques have recently received significant interests from both academia and industry due to their ability to provide spatial diversity to address the ever increasing demand for extended network coverage, higher data rates without sacrificing extra power resources, greater mobility and enhanced reliability. This thesis mainly considers two themes. Firstly, in the context of self-powered multiple-input-multiple-output (MIMO) full-duplex (FD) relaying, our research focuses on design and performance analysis of MIMO FD relaying systems in the presence of practical transmission impairments. Namely, the impact of spatial fading correlation, imperfect channel state information (CSI), loopback self-interference (LI), and co-channel interference (CCI) on the system performance are investigated. Secondly, in the context of wirelessly-powered MIMO HD relaying, our research focuses on energy beamforming which is used to maximize the overall harvested energy so as to enable longer-distance wireless power transfer when compared to the single antenna nodes. Namely, in the presence of MIMO relaying systems, hop-by-hop information and energy beamforming is proposed where the transmitted signal is steered along the strongest eigenmode of each hop. The wirelessly powered relay scavenge energy from the source information radio-frequency (RF) signal through energy beamforming, where both the time-switching receiver (TSR) and power-splitting receiver (PSR) are considered, then uses the harvested energy to forward the source message to the destination. Our research focuses on developing a comprehensive analytical framework for deriving new closed-form expressions for the outage probability and ergodic capacity for amplify-and-forward (AF) relaying systems, including simpler tight bounds and asymptotic high signal-to-noise (SNR) ratio analysis. First, the optimization problem for the design of source, relay, and destination precoding and/or decoding weight vectors which maximizes the overall signal-to-interference-plus-noise ratio (SINR) is formulated. Then, in order to get closed-form precoding and decoding weight vectors, a sub-optimal solution based on null space projection designed to completely suppress the LI and/or CCI is proposed, through which a closed-form overall SINR is presented. Simulation results show the exactness and tightness of the proposed exact and bound analytical expressions, respectively.
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Drewe, L. J. "Probing strategies for duplex DNA." Thesis, University of Cambridge, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.598653.
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Two main approaches have been adopted for the specific detection of the duplex PCR amplicon. The first investigates the potential of denaturing the amplicon so that the resulting single-strand DNA can be applied to the biosensor interface derived with a DNA probe. The work in this thesis validated such an approach using a model single-strand DNA target-probe system and demonstrated that the extent of hybridisation could be improved 3.5-fold by replacing the immobilised DNA with a peptide nucleic acid (PNA) probe of the same sequence. Hybridisation was not, however, demonstrated when the analyte consisted of denatured duplex DNA. The second approach investigated a novel method for detecting duplex PCR amplicons without their prior denaturation. By exploiting the charge properties of PNA this nucleic acid may be manipulated to strand invade duplex DNA at polypurine stretches within the target molecule. A method for the universal incorporation of polypurine motifs into any amplicon using a polypyrimidine rich 5'-tail on the specific PCR primer was adopted to both confer and control the location of strand invasion sites. PNA strand invasion of PCR amplicons generated in this manner was demonstrated both in solution and on the sensor surface and was generally observed within 10 minutes. The relative merits of adopting such an approach for the sensitive, rapid and specific detection and identification of microorganisms is critically discussed in context with alternative methods for detecting microorganisms and further DNA hybridisation formats.
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Pawlik, Aleksandra Karolina. "Duplex emulsions for healthy foods." Thesis, University of Birmingham, 2012. http://etheses.bham.ac.uk//id/eprint/3713/.
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Clear scientific links between major diseases and diet are the main reasons for a change in food processing technology and products. Duplex emulsions offer the possibility of reduction of the fat content, and also encapsulation of bio-components and their targeted delivery within the human body. In this work the formulation and production/processing of food grade W\(_1\)/O/W\(_2\) duplex emulsions were investigated in relation to emulsion’s stability. It was shown that when the osmotic pressures between the two water compartments in duplex W\(_1\)/O/W\(_2\) emulsions were balanced, there was still a release of salt in storage. The extent and rate of release was proportional to glucose concentration in the W\(_2\). Duplex emulsions are shear-sensitive and shear-intensive processing could lead to their considerable damage. By using three secondary emulsification techniques: Shirasu Porous Glass (SPG) cross-flow membranes, SPG rotating membrane and high-shear mixer, it was shown that the amount of salt released during storage depends on the emulsification technique. The SPG rotating membrane technique was used to investigate its emulsifying potential. Droplet sizes of simple O/W emulsions were independent of the dispersed phase volume, increasing with the viscosity of the continuous phase and size of the membrane pores. It was also shown that droplet size could be controlled by the concentration and properties of an emulsifier.
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Garfias-Mesias, Luis Francisco. "Pitting corrosion of duplex stainless steels." Thesis, University of Oxford, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.318008.
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Ho, F. M. "Strand exchange for duplex DNA detection." Thesis, University of Cambridge, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.604106.
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The phenomenon of strand exchange between an unlabelled double-stranded target oligonucleotide and a single-stranded, fluorophore labelled probe oliognucleotide was investigated. This behaviour was characterised using fluorescence resonance energy transfer (FRET). The individual fluorescence characteristics of the fluorophores the minor-groove binder Hoechst 33258 and the dye Oregon Green 488 were studied, as well as their properties in combination as a FRET pair. These dyes allowed the use of FRET for the study of duplex DNA without the need for covalently attaching two labels on the component strands. Two strategies were studied for the detection of a duplex target. Firstly, detection could be by monitoring the FRET process as a function of time, monitoring the fluorescence intensities at both the donor and acceptor emission peak wavelengths. Single base pair discrimination was achieved, with very high reproducibility, especially if ratiometric analysis of the emission signals was employed. The mechanism of this process was examined using mathematical modelling, and comparisons made with the experimental results. Secondly, an in-gel detection technique was investigated for the detection of the target duplex within a complex mixture. The target sequence was successfully detected from within the enzyme digestion products of plasmids extracted from cloned E. coli cells. This was performed directly from a polyacrylamide electrophoresis gel without the need for blotting, and was possible with or without polymerase chain reaction amplification. Multiplexing was also demonstrated using this in-gel strategy, giving simultaneous detection of two targets of different base sequences and lengths. Finally, the synthesis of an acceptor fluorophore labelled dendrimer was proposed. This opened up the prospect of exploiting the properties of the dendrimer to enhance the FRET signal upon strand exchange.
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Chen, Shixiang. "Division-free duplex for wireless applications." Thesis, University of Bristol, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.361075.
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Hutchings, D. "Hydrogen embrittlement of duplex stainless steel." Thesis, University of Manchester, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.631722.
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Duplex stainless steels (DSS's) are frequently used in oil and gas production and are subsequently subjected to cathodic protection. There is now growing concern about the cathodic evolution of hydrogen produced from this protection system, which may diffuse into the alloy and cause an embrittled condition. DSS's have a microstructure that is a mixture of austenite and ferrite and combines the advantages of these grades, whilst minimising their deficiences. In this research, Zeron 100 DSS was studied in six conditions to investigate the effects of hydrogen embrittlement (HE) on the various strengths and microstructures. The six conditions wer~ as follows: as-received, cold worked, age-hardened (475°C embrittlement), high temperature heat treated, rod and powder. To simulate service environments, 3.5% wt NaCI solution at ambient temperature with an applied potential of -1.1 V (SCE) was used. The effect of pre-charging for up to 550 hours at 80°C was also investigated. Test methods included slow strain rate testing (SSRT), monitoring of transient crack propagation (TCP) using circumferentially notched tensile specimens using a DC potential drop method, acoustic emission CAE) and some conventional bolt loaded fracture mechanics specimens. Test results were correlated with the varying microstructures and environmental conditions and consisted of mechanical properties, threshold crack growth including transient effects and AE data. In this work transgranular cleavage cracks were obtained in the susceptible ferrite phase as a direct result of HE; the depth of these cracks implied a high hydrogen concentration throughout the specimen. The austenite failed by ductile tearing and acted as a physical barrier to the propagation of cleavage cracks. As a result of SSR testing the best material was found to be the powder material; the fine equally dispersed austenite phase caused a lowering of the effective K value. The worst material was the high temperature heat treated type because it contained more ferrite (11:1 72%). The age-hardened material was also susceptible because of the hard and brittle ex' phase. However, regardless of the environment the UTS remained virtua]]y unchanged for each individual material, indicating that most cracking occurred in the post-UTS stage of the test. With the TCP test a lowering of the fracture load was found when an HE environment was used; daldt vs Kq curves were produced, however the DC potential drop equipment could not accurately measure crack growth because of the bridging effect of the austenite phase. The most susceptible microstructures were again the age-hardened and heat treated types. The hydrogen evolution reaction (HER) was also investigated by creating a fresh surface on the as-received DSS and studying the changes in the HER. This work showed that the effect of scratching is irreversible. Also the oxide film can not be totaHy reduced electrochemica]]y and only mechanical methods can remove the oxide films entirely. Fina]]y a means of detecting "475°C embrittlement" of DSS's was investigated using an electrochemical technique in 5M HCI. i-E curves were produced which showed the reactivation of the ferrite and austenite phases in the as-received material. By age-hardening at 475°C the two reactivation peaks merged.
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Martin, Guilhem. "Hot workability of duplex stainless steels." Phd thesis, Université de Grenoble, 2011. http://tel.archives-ouvertes.fr/tel-00721764.
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Les aciers inoxydables austéno-ferritiques présentent une microstructure biphasée dans laquelle se mêlent austénite et ferrite. Leurs caractéristiques mécaniques élevées ainsi que leur bonne tenue en corrosion en font un candidat sérieux pour remplacer les aciers inoxydables austénitiques. Malheureusement, la faible forgeabilité de ces alliages rend la fabrication de tôles particulièrement critique. En effet, le phénomène de " crique de rive " est fréquemment rencontré au cours des étapes du laminage à chaud. Par conséquent, cela nécessite des opérations supplémentaires comme le découpage des rives, ce qui aboutit à une augmentation des coûts de production. Les différents facteurs influençant la ductilité à chaud de ces aciers sont passés en revue afin d'identifier quels sont les zones d'ombres. La synthèse bibliographique révèle deux zones d'ombres : d'une part, le manque d'un essai de ductilité à chaud permettant de discriminer différentes microstructures en terme de résistance à la propagation de fissure à haute température ; et d'autre part l'absence de données quantitative concernant la partition de la déformation entre la ferrite et l'austénite lors des étapes de mise en forme à chaud. Le concept de travail essentiel de rupture a été appliqué à hautes températures. Il a été démontré que cette méthode est fiable et discriminante pour quantifier la résistance à la propagation de fissure à haute température. Elle permet également de générer un paramètre physique pertinent pour optimiser les microstructures par rapport à un mode de mise en forme donné. La technique conventionnelle de micro-grilles a été adaptée de manière à cartographier à haute température les déformations à l'échelle de la microstructure. Cette technique fournit en plus des résultats qualitatifs concernant les mécanismes de déformations, des données quantitatives à propos de la partition de la déformation entre la ferrite et l'austénite. Ces données peuvent être utilisées afin de valider les modèles qui prédisent le comportement à chaud des aciers duplex pendant les premières étapes du laminage à chaud. Les deux outils developpés au cours de cette étude permettent de donner des solutions pour éviter le phénomène de " crique de rives ".
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Soylu, B. "Phase tranformations in duplex stainless steels." Thesis, University of Cambridge, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.235281.
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Bektas, Kurtulus. "Full-duplex underwater networking using CDMA." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2004. http://library.nps.navy.mil/uhtbin/hyperion/04Mar%5FBektas.pdf.
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Sagradi, Debora Pulino. "Superplasticidade de um aço inoxidavel duplex." [s.n.], 1996. http://repositorio.unicamp.br/jspui/handle/REPOSIP/263048.
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Orientadores: Ana M. M. Nazar, Ricardo E. MedranoTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica
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Abstract: Superplasticity is the ability of certain materials to deform homogeneously with high elongations (several hundreds or thousands percent) at elevated temperatures and low strain rates. This subject of scientific and teclinological interest is not well slablished yet. The purpose of present work is to characterize and to study the superplastic behavior of a 22.5%Cr-6.4%Ni-3.0%Mo-0.16%N duplex stainless steel. Therefore, samples from sheets of the material were examined at 950°C and 98CFC by means of tensile, strain rate change and stress relaxation tests. Moreover, microstructures and cavitation process under main conditions were also analyzed. Tensile tests provided informations about elongation and deformation homogeneity. On the other hand, the strain rate change and stress relaxation tests were more suitable to determine the strain rate sensitivity. The superplastic behavior analysis was based on whole results from elongation, strain rate sensitivity and deformation uniformity. According to these criteria, the material exhibits superplastic deformation at 980X with strain rates ranging from 10 s" to ! 0' s". Under these conditions the deformation was homogeneous (without necking), the strain rate sensitivity coefficient attained 0.7 and elongation achieved 900%. During deformation: (i) the initial microstructure composed of oriented phases change to an equiaxed stable structure and (ii) cavitation process occurs. These observations suggest the grain boundary sliding as the main superplastic deformation mechanism. Key Words: super-plasticity, duplex stainless steel, tensile test, strain rate change test, stress relaxation
Doutorado
Materiais e Processos de Fabricação
Doutor em Engenharia Mecânica
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Sharafi, Shahriar. "Microstructure of super-duplex stainless steels." Thesis, University of Cambridge, 1993. https://www.repository.cam.ac.uk/handle/1810/221879.
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Mössinger, Klaus. "Innovative Duplex Filter for Hydraulic Applications." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-199519.
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For decades, duplex filters have been put to use virtually unmodified. Technologies, handling and use of materials show enormous potential for improvement. Filter element emoval/replacement is performed according to a complex process sequence. With the newly developed Duplex Filter, the market demands concerning simple filter element removal/replacement, as well as weight and pressure loss reduction are fully met.
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Martins, Alessandra Souza. "Estudo comparativo da resistÃncia à corrosÃo dos aÃos inoxidÃveis super duplex ASTM A890 / A890M grau 5A e 6A." Universidade Federal do CearÃ, 2014. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=12591.
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CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel SuperiorUma liga metÃlica que vem apresentando um desempenho satisfatÃrio em ambientes de maior agressividade à o aÃo inoxidÃvel super duplex. Esse tipo de aÃo possui boas propriedades de resistÃncia mecÃnica, resistÃncia à corrosÃo e tenacidade ao impacto. Mesmo apresentando desempenho satisfatÃrio, esses aÃos podem apresentar problemas de corrosÃo quando sofrem algum tratamento tÃrmico devido à precipitaÃÃo de uma fase deletÃria chamada de alfa linha (â), a qual precipita em temperaturas entre 300 ⁰C e 550 ⁰C e pode ocasionar uma diminuiÃÃo da resistÃncia à corrosÃo e tenacidade do material. Portanto, o objetivo deste trabalho à avaliar a resistÃncia à corrosÃo dos aÃos inoxidÃveis super duplex fundidos de grau 5A e 6A apÃs sofrerem tratamento tÃrmico a 475 ⁰C. O grau 6A se difere do 5A pela presenÃa de cobre e tungstÃnio na sua composiÃÃo quÃmica. A resistÃncia à corrosÃo dos corpos de prova foi avaliada por meio das seguintes tÃcnicas eletroquÃmicas: monitoramento do potencial de circuito aberto, polarizaÃÃo anÃdica, polarizaÃÃo cÃclica, espectroscopia de impedÃncia eletroquÃmica e temperatura crÃtica de pite. Foi realizada a caraterizaÃÃo microestrutural dos materiais, onde foi possÃvel observar sua estrutura bifÃsica composta por uma matriz ferrÃtica e ilhas de austenita em proporÃÃes coerentes. O ensaio de dureza Brinell mostrou que a dureza aumenta nas primeiras horas de tratamento tÃrmico e, depois, hà uma diminuiÃÃo nessa taxa de aumento da dureza. Os resultados eletroquÃmicos indicaram que, para os dois tipos de aÃo estudados, as amostras com 10 horas de tratamento tÃrmico apresentaram uma maior resistÃncia à corrosÃo.
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Sture, Henrik. "Integrity Evaluation of Duplex Stainless Steel Flanges." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for produktutvikling og materialer, 2012. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-19055.
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Duplex stainless steel flanges are normally forged to form, as required by the ASTM A182/A182M standard, but may also potentially be machined directly from forged stainless steel bar. In order to evaluate the integrity of such flanges, axisymmetric elastic-plastic finite element models have been developed, considering static effects such as bolt load and internal pressure. Additionally, tensile testing of a sample forged bar (UNS S31803) has been conducted. The stress distribution in a flange during gasket seating and operating conditions has been determined, as well as the degree of plastic strain caused by the bolt loads. The maximum stresses have been found to be around the same values as the minimum yield strength requirement of the studied material (UNS S31803), and the location of the maximum stress concentrations have been identified as the gasket groove. The tensile tests of the forged bar (UNS S31803) have shown that the yield and tensile strength properties are considerably higher than the standardized minimum requirements. The elastic modulus of the forged bar has also been determined, and was found to be lower than anticipated in the axisymmetric models. Some specimens have also been found to exhibit highly non-linear elastic properties.
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Weis, Karin. "Explorations of the duplex theory of hate." Berlin Logos, 2005. http://deposit.ddb.de/cgi-bin/dokserv?id=2762595&prov=M&dokv̲ar=1&doke̲xt=htm.
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Sieurin, Henrik. "Fracture toughness properties of duplex stainless steels." Doctoral thesis, Stockholm, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3964.
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Gavathiotis, Evripidis. "Drug-targetting of duplex and quadruplex DNA." Thesis, University of Nottingham, 2002. http://eprints.nottingham.ac.uk/27683/.
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This thesis investigates structural and dynamic properties of drug recognition mechanisms to duplex and quadruplex DNA using primarily high field NMR techniques and molecular dynamics simulations. The mechanism of co-operative binding of Hoechst 33258 to the DNA minor groove of duplexes that contain two binding sites such as d(CTTTTGCAAAAG)2, d(GAAAAGCTTTC)2 and d(CTTTTGGCCAAAAG)2 has been studied. NMR and other titration techniques have evidenced co-operative binding and no detection of an intermediate 1:1 complex. High-resolution NMR structure determination showed no evidence of direct contact between Hoechst 33258 molecules or DNA structure deformation that would facilitate co-operativity, Molecular dynamics simulations based on NMR data, allowed us to calculate thermodynamic quantities of the two binding events, and lead us to conclude that ligand binding can induce changes in DNA conformational flexibility in sites of the structure distant from the binding site and result in more favourable second ligand binding. The results highlight the general importance of flexibility in determining the properties of ligand-DNA interactions. The relative importance of ligand isohelicity and phasing in DNA minor groove has been investigated by studying the structure and dynamics of the 1:1 complex of Hoechst IO-d(GCAAATTTGC)2. The results suggest that DNA sequence-dependent structure and flexibility have significant role for the strong binding of Hoechst 10 to the duplex. The formation, stability, structure and dynamics of the d(TTAGGGT)4 quadruplex structure, which contains the human telomeric repeat TTAGGG, have been studied. Characteristic features of the quadruplex structure were determined and this information was used for understanding drug-quadruplex interactions. The complex of the fluorinated polycyclic methylacridinium cation RHPS4, lead compound for telomerase inhibition, with the d(TTAGGGT)4 quadruplex structure has been investigated. RHPS4 forms a stable G-quadruplex complex by endstacking externally to the a-tetrads of the Apa and Gp'T steps. This study presents detailed properties of the complex and provides further information for lead optimisation studies.
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Mohammed, Farej Ahmed. "Stress corrosion cracking in duplex stainless steels." Thesis, University of Manchester, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.488331.
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Booth, James Alexander. "Propargylamino modified bases for DNA duplex stabilisation." Thesis, University of Southampton, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.417981.
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Kim, Yoon-Jun. "Phase Transformations in Cast Duplex Stainless Steels." Ames, Iowa : Oak Ridge, Tenn. : Ames Laboratory ; distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy, 2004. http://www.osti.gov/servlets/purl/837274-V0QAJQ/webviewable/.
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Thesis (Ph.D.); Submitted to Iowa State Univ., Ames, IA (US); 19 Dec 2004.Published through the Information Bridge: DOE Scientific and Technical Information. "IS-T 2322" Yoon-Jun Kim. US Department of Energy 12/19/2004. Report is also available in paper and microfiche from NTIS.
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Wannas, Hussain. "Full Duplex Multiuser MIMO with Massive Arrays." Thesis, Linköpings universitet, Institutionen för systemteknik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-105268.
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Half-Duplex Multiuser Multiple-Input Multiple-Output (HD MU-MIMO) systemscurrently employed in communication systems are not experiencing the selfinterference(SI) problem but they are not optimal in terms of efficiency and interms of resources used (time and frequency resources). Ignoring the effect of largescalefading, we start by explaining the uplink (UL) and downlink (DL) parts ofthe MU-MIMO system and how the sum-rate is calculated. We also introduce thethree linear receivers/precoders, Maximum-Ratio Combining (MRC)/Maximum-Ratio Transmission (MRT), Zero-Forcing (ZF), and Minimum Mean-Square Error(MMSE) and which of the three types is going to be used in the study of Full-Duplex Multiuser Multiple-input Multiple-output (FD MU-MIMO) system. Thenwe introduce FD MU-MIMO system, and how the equation used to calculate thesum-rate of the UL part changes when the SI occurs, and why SI problem is notpresent in the DL part. Next, we introduce the spectral efficiency (SE), and howto calculate it and why it is taken as a parameter to compare HD and FD systems.Also the effect of SI on FD MU-MIMO system is presented through simulationgraphs, then we move to show how to reduce SI effect by increasing the number ofantennas in the base-station (BS). Lastly, we take the effect of large scale fading inorder to reach a simple statistical model in the form cumulative distribution function(CDF) graph for different values of SI and compare those of FD MU-MIMOsystem to HD MU-MIMO. The results show that FD MU-MIMO together withmassive MIMO technology is very promising and would save time and frequencyresources which means an increase in the SE but SI must be below a certain level.
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Jebur, Bilal Alauldeen. "Full duplex-transceivers : architectures and performance analysis." Thesis, University of Newcastle upon Tyne, 2017. http://hdl.handle.net/10443/4008.
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The revolution of the 5G communication systems will result in 10,000 times increase in the total mobile broadband traffic in the 2020s, which will increase the demand on the limited wireless spectrum. This has highlighted the need for an efficient frequency-reuse technique that can meet the ever-increasing demand on the available frequency resources. In-band full-duplex (FD) wireless technology that enables the transceiver nodes to transmit and receive simultaneously over the same frequency band, has gained tremendous attention as a promising technology to double the spectral efficiency of the traditional half-duplex (HD) systems. However, this technology faces a formidable challenge, that is the large power difference between the self-interference (SI) signal and the signal of interest from a remote transceiver node. In this thesis, we focus on the architecture of the FD transceivers and investigate their ability to approximately double the throughput and the spectral efficiency of the conventional HD systems. Moreover, this thesis is concerned with the design of efficient self-interference cancellation schemes that can be combined with the architecture of the FD transceiver nodes in order to effectively suppress the SI signal and enable the FD mode. In particular, an orthogonal frequency-division multiplexing (OFDM) based amplify-and-forward (AF) FD physical-layer network coding (PLNC) system is proposed. To enable the FD mode in the proposed system, a hybrid SIC scheme that is a combination of passive SIC mechanism and active SIC technique is exploited at each transceiver node of that system. Next, we propose an adaptive SIC scheme, which utilizes the normalized least-mean-square (NLMS) algorithm to effectively suppress the SI signal to the level of the noise floor. The proposed adaptive SIC is then utilized in a denoise-and-forward (DNF) FD-PLNC system to enable the FD mode. Finally, we introduce a novel overthe- air SIC scheme that can effectively mitigate the SI signal before it arrives the local analog-to-digital converter (ADC) of the FD transceiver nodes. Furthermore, the impact of the hardware impairments on the performance of the introduced SIC scheme is examined and characterized.
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Towhidlou, Vahid. "Full duplex communication in cognitive radio networks." Thesis, King's College London (University of London), 2017. https://kclpure.kcl.ac.uk/portal/en/theses/full-duplex-communication-in-cognitive-radio-networks(5453e11d-6736-48ab-b49c-090df3373807).html.
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Over the past decade mobile services have evolved from basic voice communication to mobile-broadband multimedia services and sophisticated wireless applications. Today, we cannot imagine a world without wireless communications and smart mobile devices. Any wireless communication relies on the availability of radiofrequency spectrum, which is inherently a finite resource and cannot be produced. This unprecedented growth of wireless devices and services has motivated academia and industry to look for new solutions in utilizing the wireless spectrum more intelligently and efficiently. Cognitive radio (CR) and Full Duplex (FD) communication are two promising technologies recently developed to enhance spectrum utilization and network efficiency, and combination thereof will improve the performance even further. CR technology has been extensively studied within the past 15 years and made available for commercial applications. On the other hand, full duplex communication was not deemed possible due to some complications until recently, when the advances in Self-Interference Suppression (SIS) methods made it possible to implement this technology in future wireless networks. In line with the global attention on full duplex and cognitive radio technologies, this research investigates new schemes of implementing full duplex communication in cognitive radio networks. In part of this thesis, the advantages of in-band full duplex transmissions in doubling the spectral efficiency and enhancing overall performance of a system, have been studied in a proposed scheme incorporating cooperative Automatic Repeat reQuest (ARQ) in an overlay cognitive radio network. It is shown that a full duplex cooperative ARQ protocol will increase the throughput of primary and secondary networks, without any degradation on primary network performance. Another part of this thesis focuses on asynchronous bidirectional FD communication in a CR system. While detection probability is enhanced due to cooperative sensing, the probability of collision and average duration of collisions are decreased significantly thanks to the implementation of asynchronous full duplex transmissions. These gains in network performance are additional to improved throughput of secondary network achieved through implementation of full duplex transmission. The proposed schemes are mathematically analyzed and have been numerically verified through extensive simulations. As a contribution to IEEE 802.22 Standard revision, a novel suggestion incorporating the use of directional sector antennas, and full duplex operation of secondary users in a Wireless Regional Area Network (WRAN) has been proposed in another part of this thesis and it has been shown how research achievements may be implemented in practice. A summary of the thesis plus some suggestions for future work conclude this thesis.
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Dalton, John Christian. "Surface Hardening of Duplex Stainless Steel 2205." Case Western Reserve University School of Graduate Studies / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=case1480696856644048.
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Dana, Seresht Mahmoudreza. "Material Selection for Deepwater Gate Valves." Thesis, KTH, Materialvetenskap, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-170023.
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Material selection is an important step during the design process of an object. The goal is to produce an object to meet the requirement with minimum cost. During the recent years with discovery of oil and gas in deep water, oil and gas industry facing new challenges of handling corrosive material in seabed that gives more importance and criticality to material selection of equipment for this kind of application. Hydrogen sulfide (H2S), chloride and carbon dioxide (CO2) have made the big challenges for material that handle corrosive fluids in the seabed.This report presents a brief review of material selection for two parts of deepwater gate valve, Body and Gate. It is mostly focused on mechanical properties and required corrosion resistance. Ferritic alloys with low PRE numbers and low mechanical properties and also austenitic alloys with low yield strength are not a proper option for this case. Alloy 2205 is the most common stainless steel which is used in deep water gate valve production. There are other alloys in duplex group that show better mechanical and chemical properties than alloy 2205 but because of their high expense are not used by industries.
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Recco, Abel André Cândido. "Estudo da obtenção e das propriedades dos filmes de TiN e TiC depositados sobre aços ferramentas AISI H13 e D2 nitretados e não nitretados." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/3/3133/tde-16042009-140247/.
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Filmes de nitreto de titânio e carbeto de titânio foram obtidos por deposição reativa via magnetron sputtering, utilizando como gases reativos, nitrogênio e metano, respectivamente. Foram depositados filmes de TiN e TiC, primeiramente sobre substratos de aços ferramenta AISI H13 e AISI D2 temperados e revenidos. Posteriormente, realizou-se o tratamento duplex de nitretação e deposição de TiN e TiC em reator híbrido, construído durante o presente trabalho. Os revestimentos foram caracterizados por microscopia eletrônica de varredura, difração de raios-X, espectrometria XPS e WDS e a rugosidade foi caracterizada por microscopia de força atômica. As propriedades mecânicas dos filmes foram determinadas utilizando a técnica de nanoindentação instrumentada, para avaliar a dureza(H), o módulo de elasticidade reduzido (E*), a recuperação elástica(we), a razão H/E* e a relação H3/E*2. Além disso, a adesão do filme ao substrato foi avaliada usando ensaios Rockwell e esclerometria linear. A resistência ao risco dos filmes depositados foi avaliada por nanoesclerometria instrumentada. O tratamento termoquímico de nitretação a plasma foi realizado em condições experimentais que inibem a formação da camada branca obtendo, assim, somente zona de difusão. Os resultados obtidos mostraram que quando os filmes de TiN e TiC são depositados sobre substratos não nitretados a adesão do filme cerâmico ao substrato metálico é baixa. O endurecimento do substrato, devido à nitretação a plasma, resultou em uma melhoria significativa na adesão(LC40 N) do filme de TiN sobre os substratos de aços ferramenta. Entretanto, o endurecimento prévio e o aumento da capacidade de suportar carga do substrato não constituem uma garantia de melhora de adesão do filme cerâmico ao substrato metálico. Para o filme de TiC depositado sobre aços ferramenta nitretados, a adesão(LC10 N) ao substrato foi baixa. A grande diferença entre as propriedades elastoplásticas, do filme de TiC e do substrato nitretado são as responsáveis pela baixa adesão. Este comportamento é semelhante ao observado para filmes de TiN e TiC depositados sobre os aços ferramenta não nitretados. Uma alternativa encontrada para melhorar a adesão dos filmes cerâmicos ao substrato foi a deposição de multicoberturas de TiN/TiC, depositados de modo a aumentar gradativamente os valores de H/E*, da relação H3/E*2 e da recuperação elástica obtendo, assim, um gradiente funcional destas propriedades. Em relação aos ensaios de nanoesclerometria conclui-se que a dureza não é por si só 2 determinante da profundidade residual no ensaio. Filmes com mesmo valor de dureza podem apresentar profundidades residuais diferentes. Nos ensaios de nanoesclerometria os filmes com altos valores de razão H/E*, da relação H3/E*2 e recuperação elástica possuem profundidades residuais menores.DC Triode Reactive Magnetron Sputtered TiN and TiC films were deposited on quenched and tempered AISI H13 AISI D2 tool steels, and silicon (111) substrates, under nitrogen and argon or methane and argon reactive plasma. Hybrid duplex treatments were carried out in a home-built hybrid reactor, where pulsed plasma nitriding and unbalanced DC Reactive Magnetron Sputtering were performed in the same cycle, without exposing the surface of the sample to atmospheric pressure. The ceramic thin films were characterized by X-ray diffraction, WDS spectrometry, scanning electron microscopy, atomic force microscopy, depth sensing techniques (nanoscale), nanoscratch tests, Rockwell C and linear sclerometry adhesion tests. Nanoscale depth sensing was used for measuring hardness (H), Young modulus (E*), the H/E* ratio (elastic strain to failure), resistance to plastic deformation, H3/E*2 and elastic recovery. The pulsed plasma nitriding was performed in conditions which avoided the formation of a white layer obtaining only a diffusion zone. When TiN and TiC films were deposited on the quenched and tempered tool steels the adhesion of the ceramic films to the substrate was poor. When the steels were plasma nitrided before deposition the adhesion of the TiN layer to the substrate was improved. However, the adhesion of the TiC film deposited on the nitrided tool steels was also very poor. Therefore, plasma nitriding does not guarantee a better adhesion of the TiC film to the substrate. The abrupt transition of mechanical properties (hardness, Young Modulus and elastic recovery) between the TiC film and the substrate were responsible for the lower adhesion observed. To improve the adhesion of the ceramic film to the substrate, TiN-TiC multilayers were deposited on the surface of the nitrided tool steels, so as to obtain functionally graded films, in which the values of H/E* ratio and elastic recovery, increased in a less abrupt way from the substrate to the film. In the nanoscratch test high it was observed that high values of the H/E* and the H3/E*2 ratios and of the elastic recovery presented lower residual scratch depth.
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Centeno, Dany Michell Andrade. "Análise microestrutural de junta brasada de aço inoxidável duplex UNS S32101, UNS S32304, UNS S32750 e UNS S32707 com metal de adição a base de níquel." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/3/3133/tde-19092014-111340/.
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Os aços inoxidáveis duplex (AID) caracterizam-se pela sua microestrutura composta por austenita numa matriz ferrítica, com fração volumétrica média de 50% para cada fase. A combinação destas características confere-lhes excelente resistência mecânica e à corrosão. A soldagem/junção destes aços é frequentemente uma operação crítica, já que, ao sofrer ciclos térmicos, estes aços têm suas propriedades alteradas. Portanto, processos de junção com ausência de gradientes de temperatura, como a brasagem, mostram-se uma solução prática para a junção destes aços. No entanto, o adequado desenvolvimento do processo de brasagem em AID envolve considerações importantes a respeito da escolha dos parâmetros de processamento e metal de adição em conjunto com os ciclos térmicos de aquecimento e resfriamento. O presente estudo pretende avaliar a brasabilidade dos AID UNS S32101(baixa liga), UNS S32304 (baixa liga), UNS S32507 (superduplex) e UNS S32707(hiperduplex), mediante a caracterização da junta brasada. Estes aços foram brasados em forno continuo com metal de adição BNi-7 (Ni-Cr-P), na temperatura de 1100oC, por tempos de 32 min e 12 min, seguidos de resfriamento em forno, utilizando-se folgas de 0,5, 0,3 e 0,0 mm. A junta brasada foi caracterizada utilizando-se microscopia ótica e microscopia eletrônica de varredura (MEV). A identificação microestrutural foi realizada via Microanálise Química de Energia Dispersiva de Raios-X (EDS) e difração de Raios-X. Foi identificada na junta brasada dos diferentes AID a fase rica em níquel, assim como fases prejudiciais compostas por fosfetos de níquel e cromo. A fase rica em níquel, que usualmente é denominada de -Ni, apresenta-se preferencialmente em toda a região da junta, sem a presença de fase intermetálica contínua no centro da junta. No caso dos aços inoxidáveis super e hiperduplex esses apresentaram a formação de fase sigma na região da interface da junta, do lado do metal de base, devido aos ciclos térmicos de brasagemThe duplex stainless steels (DSS) are characterized by its microstructure consisting of austenite in a ferritic matrix with mean volumetric fraction of 50% for each phase. The combination of these features gives them excellent mechanical strength and corrosion resistance. The welding / joining of these steels are often considered as a critical operation, since, subjected to thermal cycles, they have their microstructures changed and, consequently, their properties. Therefore, joining processes without temperature gradients, like brazing, are shown as a practical solution for joining these steels. However, the proper development of brazing process of DSS involves important issues concerning the choice of processing parameters and the brazing filler metal together with heating and cooling brazing thermal cycles. This study aims at evaluating the brazeability of DSS UNS S32101 (lean duplex), UNS S32304 (lean duplex), UNS S32507 (superduplex) and UNS S32707 (hyperduplex) by characterizing the brazed joint. These steels were brazed in a furnace with filler metal BNi-7 (Ni-Cr-P) at 1100°C for times of 32 min and 12 min, followed by cooling in a continuous brazing furnace, with joint gaps of 0.5 , 0.3 and 0.0 mm. The brazed joint was characterized using optical microscopy and scanning electron microscopy (SEM). The phase identifications were performed by microanalysis using energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction. Results showed, for non-ideal joint gaps, in all duplex used in this work, the Ni rich solid solution, as well as deleterious phases composed of nickel and chromium phosphides. The ideal gap presented Ni rich solid solution, usually called -Ni, was found continuously without a continuous intermetallic region in the joint center. In the case of super duplex and hyperduplex brazing, the brazing thermal cycles produced the formation of sigma phase in the region of the joint interface, in the base metal.
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Axelsson, Magnus, and Marcus Dalgren. "The double dupe : den dubbla duperingen." Thesis, University West, Department of Social and Behavioural Studies, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:hv:diva-243.
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Aguiar, Denilson José Marcolino de. "Estudo da formação e reversão de martensita induzida por deformação na austenita de dois aços inoxidáveis dúplex." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/3/3133/tde-03072013-112618/.
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No presente trabalho foram estudados os fenômenos de encruamento e, principalmente, a formação e reversão da martensita alfa-linha (a\', cúbica de corpo centrado, CCC, ferromagnética) induzida por deformação em um aço inoxidável dúplex UNS S31803 e um super dúplex UNS S32520. Inicialmente, as microestruturas dos dois materiais na condição solubilizada foram caracterizadas com auxílio de várias técnicas complementares de análise microestrutural. Foram determinadas fração volumétrica, estrutura cristalina, composição química, tamanho e morfologia das duas fases (ferrita e austenita). Posteriormente, os dois aços foram deformados por dois métodos: a laminação a frio, dividida em vários estágios, com menores graus de deformação e a limagem, sendo que o cavaco limado resultante apresenta altos graus de deformação. Algumas amostras deformadas foram recozidas. Os fenômenos de encruamento, formação e reversão de martensita induzida por deformação na austenita, recuperação, recristalização da austenita e da ferrita no cavaco limado foram estudados predominantemente por difratometria de raios X e usando o método de Rietveld. A difratometria de raios X também foi utilizada para determinação das microdeformações residuais e tamanhos de cristalito (subgrão), calculadas a partir do alargamento dos picos de difração causado pelas deformações. Desta forma, puderam-se comparar os níveis de deformação da laminação e limagem. Qualitativamente, a formação e reversão da martensita induzida por deformação também foi estudada por meio de medidas magnéticas utilizando-se dados de saturação magnética das curvas de histerese obtidas com o auxílio de um magnetômetro de amostra vibrante. Observou-se que para o aço inoxidável dúplex, tanto a laminação quanto a limagem causaram a formação de martensita induzida por deformação e para o aço inoxidável super dúplex, apenas a limagem promoveu essa transformação. Em comparação com o aço dúplex, o aço super dúplex apresentou maior resistência à formação de martensita induzida por deformação, pois apresenta uma austenita mais rica em nitrogênio e uma maior propensão à formação de fase sigma durante o recozimento, pois apresenta uma ferrita mais rica em cromo e nitrogênio.In the present work the phenomena of strain hardening, formation and reversion of the strain induced alpha-prime martensite (a\', body centered cubic, BCC, Ferromagnetic) in an UNS S31803 duplex and UNS S32520 super duplex stainless steels have been studied. Firstly, the microstructures of both materials in the solution annealed condition were characterized with the aid of several microstructural analysis complementary techniques. The volume fraction, crystalline structure, chemical composition, size and morphology of the two phases (ferrite and austenite) have been determined. Further, both steels were deformed by two methods: cold rolling, divided into several stages, with lower strain levels than filing, which the chips resulting had higher strain levels. The phenomena of strain hardening, formation and reversion of strain induced martensite in the austenite phase, recovery and recrystallization of austenite and ferrite phases have been studied, mainly using X-ray diffraction and the Rietveld method. X-ray diffraction was also used to determine the residual microstrain and crystallite size (sub grain), calculated from the diffraction peak broadening caused by straining. Thus, the levels of cold rolling and filing strains could be compared. Qualitatively, the formation and reversion of strain induced martensite was also studied by magnetic measurements using data from magnetic saturation of hysteresis curves obtained with the aid of a vibrating sample magnetometer. It has been observed that for the duplex stainless steel, both filing as well as cold rolling promoted strain induced martensite. On the other hand, for the super duplex stainless steel, just filing promoted this transformation. In the comparing with duplex, the super duplex stainless steel austenite is more stable that is why is richer in nitrogen, so, the strain induced martensite formation is more difficult. The easier sigma phase precipitation during annealing as well in the super duplex stainless steel is due higher levels of chrome and molybdenum than the duplex stainless steel.
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Videira, Arthur Moraes e. [UNESP]. "Influência do aporte térmico da soldagem GTAW no balanço de fases Ferrita/Austenita do Aço Inoxidável Duplex UNS S32205." Universidade Estadual Paulista (UNESP), 2016. http://hdl.handle.net/11449/136319.
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O emprego de aços inoxidáveis duplex na indústria atual vem aumentando devido as suas características que combinam boas propriedades mecânicas e de resistência à corrosão. Esses aços são constituídos por uma estrutura bifásica com frações volumétricas de 50% ferrita e 50% austenita. Portanto, o desenvolvimento de técnicas para melhorar a soldagem dos aços duplex se faz necessário, de modo a garantir que o balanço de fases e as propriedades do material não sejam severamente prejudicados neste processo. Este trabalho tem o objetivo de caracterizar juntas soldadas com o processo GTAW (Gas Tungsten Arc Welding) no aço inoxidável duplex UNS S32205. Foram realizadas soldagens na condição autógena com aporte térmico variando entre 261,00 J/mm e 652,50 J/mm. Seguiu-se com a análise do metal base e dos cordões de solda mediante ensaios de dureza Vickers, EDS (Espectroscopia por Dispersão de Energia), microscopia eletrônica de varredura (MEV) e microscopia óptica (MO). Os resultados apresentaram a região do metal de solda com fração volumétrica de austenita variando entre de 21,71% e 33,89%. Essa variação se deve às menores taxas de resfriamento dos aportes térmicos com valores maiores, que permitem uma maior formação de austenita. Quanto a geometria do cordão, foi observado que valores maiores de aporte térmico, provocaram cordões mais largos e profundos, variando entre 3,9 e 5,9 mm de largura e 0,65 a 1,29 mm de profundidade. Na zona termicamente afetada mais próxima do metal de solda, a dureza Vickers apresentou valores maiores que o metal base, devido a presença de maior percentual de ferrita nessa região. Não se identificou a presença de fases frágeis no material.
The use of duplex stainless steels in industry is increasing due to their characteristics that combine good mechanical and corrosion resistance properties. These steels are comprised of a biphasic structure volume fraction of 50% ferrite and 50% austenite. Therefore, the development of techniques to improve the welding of duplex steels it is necessary, in order to ensure that the phase balance and the material properties are not severely harmed in the process. This work aims to characterize welded joints with the GTAW process in UNS S32205 duplex stainless steel. Autogenous welds were performed with heat input ranging from 261.00 J/mm and 652.50 J/mm. The next step was the analysis of base metal and weld beads by Vickers hardness testing, EDS, electronic and optical microscopy. The results showed the weld metal region with volume fraction of austenite ranging between 21.71% and 33.89%. This variation is due to the lower cooling rates of high heat input values, wich allow a greater formation of austenite. About the geometry, it was observed that higher values of heat input, led to wider and deeper welded joints, ranging between 3.9 and 5.9mm width and 0.65 and 1.29mm depth. In the nearest heat affected zone of the weld metal, Vickers hardness showed higher values than the base metal due to the presence of higher percentage of ferrite. Was not identified brittle phases in the material.
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Videira, Arthur Moraes e. "Influência do aporte térmico da soldagem GTAW no balanço de fases Ferrita/Austenita do Aço Inoxidável Duplex UNS S32205 /." Ilha Solteira, 2016. http://hdl.handle.net/11449/136319.
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Orientador: Vicente Afonso VentrellaResumo: O emprego de aços inoxidáveis duplex na indústria atual vem aumentando devido as suas características que combinam boas propriedades mecânicas e de resistência à corrosão. Esses aços são constituídos por uma estrutura bifásica com frações volumétricas de 50% ferrita e 50% austenita. Portanto, o desenvolvimento de técnicas para melhorar a soldagem dos aços duplex se faz necessário, de modo a garantir que o balanço de fases e as propriedades do material não sejam severamente prejudicados neste processo. Este trabalho tem o objetivo de caracterizar juntas soldadas com o processo GTAW (Gas Tungsten Arc Welding) no aço inoxidável duplex UNS S32205. Foram realizadas soldagens na condição autógena com aporte térmico variando entre 261,00 J/mm e 652,50 J/mm. Seguiu-se com a análise do metal base e dos cordões de solda mediante ensaios de dureza Vickers, EDS (Espectroscopia por Dispersão de Energia), microscopia eletrônica de varredura (MEV) e microscopia óptica (MO). Os resultados apresentaram a região do metal de solda com fração volumétrica de austenita variando entre de 21,71% e 33,89%. Essa variação se deve às menores taxas de resfriamento dos aportes térmicos com valores maiores, que permitem uma maior formação de austenita. Quanto a geometria do cordão, foi observado que valores maiores de aporte térmico, provocaram cordões mais largos e profundos, variando entre 3,9 e 5,9 mm de largura e 0,65 a 1,29 mm de profundidade. Na zona termicamente afetada mais próxima do metal de sold... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: The use of duplex stainless steels in industry is increasing due to their characteristics that combine good mechanical and corrosion resistance properties. These steels are comprised of a biphasic structure volume fraction of 50% ferrite and 50% austenite. Therefore, the development of techniques to improve the welding of duplex steels it is necessary, in order to ensure that the phase balance and the material properties are not severely harmed in the process. This work aims to characterize welded joints with the GTAW process in UNS S32205 duplex stainless steel. Autogenous welds were performed with heat input ranging from 261.00 J/mm and 652.50 J/mm. The next step was the analysis of base metal and weld beads by Vickers hardness testing, EDS, electronic and optical microscopy. The results showed the weld metal region with volume fraction of austenite ranging between 21.71% and 33.89%. This variation is due to the lower cooling rates of high heat input values, wich allow a greater formation of austenite. About the geometry, it was observed that higher values of heat input, led to wider and deeper welded joints, ranging between 3.9 and 5.9mm width and 0.65 and 1.29mm depth. In the nearest heat affected zone of the weld metal, Vickers hardness showed higher values than the base metal due to the presence of higher percentage of ferrite. Was not identified brittle phases in the material.
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Borsato, Karin Soldatelli. "Caracterização microestrutural e de propriedades mecânicas de chapas espessas de aço inoxidável duplex UNS 31803, submetido a ciclos térmicos de soldagem." Florianópolis, SC, 2001. http://repositorio.ufsc.br/xmlui/handle/123456789/79465.
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Tese (doutorado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Engenharia MecânicaMade available in DSpace on 2012-10-18T04:20:28Z (GMT). No. of bitstreams: 0Bitstream added on 2014-09-25T20:52:33Z : No. of bitstreams: 1 181512.pdf: 59498738 bytes, checksum: e902ba758060acae90c9cb4734998fe9 (MD5)
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Yoshimoto, Yui, Yoshiyuki Karuno, and Shinji Imahori. "Dynamic Programming Algorithms for Duplex Food Packing Problems." IEEE, 2010. http://hdl.handle.net/2237/14459.
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Alsarraf, Jalal. "Hydrogen embrittlement susceptibility of super duplex stainless steels." Thesis, Cranfield University, 2010. http://dspace.lib.cranfield.ac.uk/handle/1826/4562.
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This thesis describes the metallurgical and environmental factors that influence hydrogen embrittlement of super duplex stainless steels and presents a model to predict the rate at which embrittlement occurs. Super duplex stainless steel has an austenite and ferrite microstructure with an average fraction of each phase of approximately 50%. An investigation was carried out on the metallurgical and environmental factors that influence hydrogen embrittlement of super duplex stainless steels. Tensile specimens of super duplex stainless steel were pre-charged with hydrogen for two weeks in 3.5% NaCl solution at 50º C at a range of applied potentials to simulate the conditions that exist when subsea oilfield components are cathodically protected in seawater. The pre-charged specimens were then tested in a slow strain rate tensile test and their susceptibility to hydrogen embrittlement was assessed by the failure time, reduction in cross-sectional area and examination of the fracture surface. The ferrite and austenite in the duplex microstructures were identified by analysing their Cr, Ni, Mo and N contents in an electron microscope, as these elements partition in different concentrations in the two phases. It was shown that hydrogen embrittlement occurred in the ferrite phase, whereas the austenite failed in a ductile manner. An embrittled region existed around the circumference of each fracture surface and the depth of this embrittlement depended on the hydrogen charging time and the potential at which the charging had been carried out. The depth of embrittlement was shown to correlate with the rate of hydrogen diffusion in the alloy, which was measured electrochemically using hydrogen permeation and galvanostatic methods. A two-dimensional diffusion model was used to calculate the hydrogen distribution profiles for each experimental condition and the model could be employed to provide predictions of expected failure times in stressed engineering components.
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Negrat, A. "Implementation strategy for single-frequency duplex radio telephone." Thesis, Swansea University, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.638307.
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A two-way link is a very desirable requirement for conversational communications. The design of such link should account for any restraints to avoid interruption, during information exchange between two parties. In this thesis, a single carrier frequency scheme is introduced to provide a concurrent two-way communication. The system uses an analogue mode (single-frequency duplex), receiving of f1 whilst also transmitting on the same frequency. In this method, both the transmitter and receiver operate in such a manner that their signal appears to all intents and purposes simultaneously, permitting a normal two-way conversation to take place. This technique is a potential step forward towards an alternative form for point-to-point communication systems. The main contributions of this thesis are outlined below: • the concept of single-frequency duplex system has been introduced. The demonstration of this concept has been achieved by implementing a new system. • Mathematical analysis is introduced as a way of understanding the gating waveform of FM signal, and to investigate the effect of bandwidth and distortion on the quality of the signal. An FM signal with high modulation index, theoretically has infinite bandwidth; on the one hand, any band limiting will cause distortion; on the other hand, putting two FM signals next to each other in the frequency band, and not band limiting them will cause mutual interference. Gating the FM signal ON/OFF was demonstrated by experiment in this work. • A comparative study of cordless telephones world-wide was made. This study gives an overview of major system elements, and to show clear understanding of concurrent two-way communication, either of Frequency Division Duplex (FDD) or Time Division Duplex (TDD).
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Bruce, Greg. "An investigation of duplex perception with musical triads." Thesis, University of Birmingham, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.368285.
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Duplex perception (DP) occurs when a stimulus simultaneously contributes to the perception of two auditory events (Rand, 1974), thus violating the principle of exclusive allocation. One interpretation of DP is that it is the consequence of independent auditory modules [speech/music vs. acoustical] of which one `mode' [phonetic/musical] has `perceptual precedence' (Liberman and Mattingly, 1989). The more common scene analysis view is that DP is the consequence of competing cues for organisation (Bregman, 1987,1990). This thesis attempted to explore DP with musical triads. It was found that tonal fusion was affected when triads were presented dichotically. Secondly, these `duplexed' triads evinced a trade-off between mode and note performance, modulated by presentation (monaural vs. dichotic). Thirdly, sequential grouping had no effect on DP. Fourthly, the relative timing of the notes in a chord had little effect on tonal fusion or DP. Finally, there was no evidence for subliminal tonal fusion, which contradicted the notion of perceptual precedence in DP. Although the findings support the idea that DP is the product of competing cues (e. g. spatial location vs. musical schemas), the insensitivity of triads to temporal-sequential organisation highlights important differences between DP with speech and music.
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Rieder, Ester Schmidt. "The passivity of a super duplex stainless steel." Thesis, University of Birmingham, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.272490.
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Vallejos, Elvira PeÌrez. "What duplex perception tells us about auditory organisation." Thesis, University of Liverpool, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.428233.
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Cohen, Laura Jane Rachel. "Some effects of hydrogen on duplex stainless steels." Thesis, University of Cambridge, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.292256.
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Marrow, Thomas James. "Fatigue mechanisms in an embrittled duplex stainless steel." Thesis, University of Cambridge, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.386998.
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Hechler, Oliver. "Über das Ermüdungsverhalten von Konstruktionen aus Duplex-Stahl /." Aachen : Shaker, 2008. http://d-nb.info/991819977/04.
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Malik, Hassan. "Distributed MAC protocol for full-duplex wireless networks." Thesis, University of Surrey, 2018. http://epubs.surrey.ac.uk/846235/.
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Full-duplex (FD) communication is considered to be a promising technology to address the problem of radio spectrum congestion due to the increasing demand for wireless communication services. This thesis investigates the problem of asymmetric data flow between downlink and uplink in a system with symmetric radio resource allocation, i.e. FD. The aim is to devise a model by exploiting the coupling nature of FD downlink and uplink transmission powers to maximise the downlink data rate while ensuring the quality of service (QoS) of uplink transmission. Whilst the aim is to maximise the spectrum efficiency gain that can be achieved with FD enabled cellular networks, this thesis presents D-MAC: a novel distributed MAC protocol. D-MAC allows interfering nodes to cooperate and implement an interuser interference estimation mechanism to gather the interference information with minimum overhead. Furthermore, D-MAC includes interference aware joint user equipment (UE) scheduling and power allocation methods. Computing the optimal resource allocation and transmission rates is non-linear, non-convex combinatorial optimisation and achieving a globally optimal solution is not possible in practice. Therefore, D-MAC uses a low complexity iterative approach for resource allocation and ensures that channel bandwidth is shared fairly across all UEs. Finally, a detailed evaluation of D-MAC performance is presented and compared to the half-duplex (HD) system, FD system with round robin and FD system with exhaustive search. It is shown that the D-MAC achieves as much as 62% throughput improvement compared to an HD system with symmetric traffic model and 49% with asymmetric traffic model in an outdoor multi-cell scenario under the limits of practical self-interference cancellation. Further, D-MAC also reduces the round-trip propagation delay, involved from the point at which the UE sends the request to the base station to the point at which the UE realize the result of contention.
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Marafini, Pietro. "Biophysical studies of oligonucleotides containing duplex stabilising modifications." Thesis, University of Oxford, 2016. https://ora.ox.ac.uk/objects/uuid:12419634-0b68-4199-aeaf-aaedb8e7e6d3.
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Chemically modified DNA and RNA probes have been used in numerous diagnostic (e.g. fluorogenic PCR and in situ hybridisation) and therapeutic (e.g. exon-skipping and antisense) applications to increase duplex stability and facilitate mismatch discrimination. There is a constant need for well-studied modifications, and to this end X-pyrene was evaluated as a new cytosine analogue that combines enhanced p-stacking, hydrogen bonding and electrostatic interactions to greatly increase the stability of bulged DNA duplexes and DNA/RNA hybrid duplexes. X-pyrene is highly selective for guanine, and even more importantly duplex stability is reduced dramatically when X-pyrene or a neighbouring base is mismatched. NMR and fluorescence studies indicate that the pyrene moiety stacks within the DNA double helix. To enable easier access to this modification, a reductive amination labelling strategy was developed to produce pyrene-functionalised nucleobase analogues which allowed an easier synthesis of X-pyrene. Amino C6 dT was successfully functionalised with this methodology as well, obtaining the duplex stabilising mono- and di-labelled products. Additionally, a much simpler pyrene-modified thymidine monomer (U-pyrene) was selected for further studies. Single and multiple additions of U-pyrene were found to significantly increase the melting temperature of dsDNA without perturbing the B-DNA duplex, as shown by UV and CD spectroscopy. Interestingly, thermodynamic studies showed that four additions of U-pyrene increased the binding constant of a 14-mer oligonucleotide to its complementary strand 10000-fold when compared to the unmodified control. Two oligonucleotides containing a single addition of U-pyrene were also crystallised and their structures were studied by X-ray diffraction. To the author's knowledge these represent the first examples of X-ray crystal structures of a chemically modified pyrene oligonucleotide. They also proved to be of great interest as they highlight the capacity of U-pyrene to facilitate the production of interesting nanostructures.
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Zhang, Chunqing. "Flexible duplex transceiver : architecture optimisation and performance evaluation." Thesis, University of Bristol, 2018. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.752781.
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Wei, Z. "Energy efficiency oriented full duplex wireless communication systems." Thesis, University of Liverpool, 2017. http://livrepository.liverpool.ac.uk/3011759/.
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Full-duplex (FD) transmission is a promising technique for fifth generation (5G) wireless communications, enabling significant spectral efficiency (SE) improvement over existing half-duplex (HD) systems. However, FD transmission consumes higher power than HD transmission, especially for millimetre wave band. Therefore, energy efficiency (EE) for FD systems is a critical yet inadequately addressed issue. This thesis addresses the critical EE challenges and demonstrates promising solutions for implementing FD systems, as detailed in the following contributions. In the first contribution, a comprehensive EE analysis of the FD and HD amplify-and-forward (AF) relay-assisted 60 GHz dual-hop indoor wireless systems is presented. An opportunistic relay mode selection scheme is developed, where FD relay with different self-interference (SIC) techniques or HD relay is opportunistically selected. Together with transmission power adaptation, EE is maximised with given channel gains. A counter-intuitive finding is shown that, with a relatively loose maximum transmission power constraint, FD relay with two-stage SIC is preferable to both FD relay with one-stage SIC and HD relay, resulting in a higher optimised EE. A full range of power consumption sources are considered to rationalise the analysis. The effects of imperfect SIC at relay, drain efficiency and static circuit power on EE are investigated. Simulation results verify the theoretical analysis. In the second contribution, EE oriented resource allocation for FD decode-of-forward (DF) relay-assisted 60 GHz multiuser systems is investigated. In contrast to the existing SE oriented designs, the proposed scheme maximises EE for FD relay systems under cross-layer constraints, addressing the typical problems at 60 GHz. A low-complexity EE-orientated resource allocation algorithm is proposed, by which the transmission power allocation, subcarrier allocation and throughput assignment are performed jointly across multiple users. Simulation results verify the analytical results and confirm that the FD relay systems with the proposed algorithm achieve a higher EE than the FD relay systems with SE oriented approaches, while offering a comparable SE. In addition, a much lower throughput outage probability is guaranteed by the proposed resource allocation algorithm, showing its robustness against channel estimation errors. In the third contribution, it is noticed that in wireless power transfer (WPT)-aided relay systems, the SE of the source-relay link plays a dominant role in the system SE due to limited transmission power at the WPT-aided relay. A novel asymmetric protocol for WPT-aided FD DF relay systems is proposed in multiuser scenario, where the time slot durations of the two hops are designed to be uneven, to enhance the degree of freedom and hence the system SE. A corresponding dynamic resource allocation algorithm is developed by jointly optimising the time slot durations, subcarriers and transmission power at the source and the relay. Simulation results con rm that, compared to the symmetric WPT-aided FD relay (Sym-WPT-FR) and the time-switching based WPT-aided FD relay (TS-WPT-FR) systems in the literature, the proposed asymmetric WPT-aided FD relay system achieves up to twice the SE and higher robustness against the relay's location and the number of users. In the final contribution, to strike the balance between high SE and low power consumption, a hybrid duplexing strategy is developed for distributed antennas (DAs) systems, where antennas are capable of working in hybrid FD, HD, and sleeping modes. To maximise the system EE with low complexity, activation/deactivation of transmit/receive chain is first performed, by a proposed channel-gain-based DA clustering algorithm, which highlights the characteristics of distributed deployment of antennas. Based on the DAs' con figuration, a novel distributed hybrid duplexing (D-HD)-based and EE oriented algorithm is proposed to further optimise the downlink beamformer and the uplink transmission power. To rationalise the system model, self-interference at DAs, co-channel interference from uplink users to downlink users, and multiuser interference in both uplink and downlink are taken into account. Simulation results confirm that the proposed system provides significant EE and SE enhancements over the colocated FD MIMO system, showing the advantages in alleviating high path loss as well as in cutting the carbon footprint. Compared to the sole-FD DA system, the proposed system shows much higher EE with marginal loss in SE. Also, the SIC operation in the proposed system is much more simplified compared to the two benchmarks.
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Correa, André Luiz. "Avaliação ultrassonográfica ao duplex Doppler colorido da varicocele." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/5/5151/tde-21062010-172157/.
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INTRODUÇÃO: A varicocele é a dilatação das veias do plexo pampiniforme do testículo. A associação entre a varicocele e a infertilidade é diagnosticada em 20 a 40% dos homens inférteis. Atualmente, o estudo ultrassonográfico da varicocele é realizado com o paciente na posição supina antes e durante a realização de Valsalva, levando-se em consideração o diâmetro das veias (> 0,20cm), e a presença de refluxo maior que 1, segundo ao estudo Doppler espectral. OBJETIVO: A) Propor uma nova metodologia na avaliação ultrassonográfica da varicocele. B) Avaliar a concordância dos achados no exame ultrassonográfico com Doppler colorido dos vasos dos plexos pampiniformes e as alterações no espermograma na infertilidade masculina. C) Avaliar a correlação entre o diâmetro de um dos vasos dos plexos pampiniformes e as alterações no espermograma na infertilidade masculina. MÉTODOS: Foram examinados 266 pacientes, provenientes do setor de reprodução humana do Hospital das Clínicas da Universidade de São Paulo (HCUSP), por meio de duplex Doppler colorido, inicialmente com o paciente em decúbito dorsal e posteriormente, após 5 minutos de espera, na posição ortostática, realizando as medidas dos diâmetros transversais dos plexos pampiniforme nas duas posições, tanto em repouso como em Valsalva. Ao estudo pulsado foi considerado refluxo patológico apenas quando persistia por mais de 1 segundo, com uma velocidade superior que 2 cm/s. Estes pacientes também foram submetidos a analise seminal. RESULTADOS: Em relação à metodologia de realização do exame, observou-se aumento no diâmetro do plexo pampiniforme apenas com a variação da posição de cerca de 18% à direita e 5,9% à esquerda, bem como aumento na detecção do refluxo venoso na posição ortostática, de 23% à direita e 6,8% à esquerda. Observou-se também correlação direta entre as alterações no espermograma com o refluxo venoso, 65% à direita e 86% à esquerda, o mesmo não ocorrendo com o diâmetro do plexo pampiniforme. CONCLUSÕES: A) O exame de ultrassongrafia com Doppler colorido deve ser realizado na posição ortostática, após um período de latência de no mínimo cinco minutos, com condições ambientais confortáveis e manobra de esforço. B) Houve concordância significativa entre o refluxo venoso nos plexos pampiniformes e as alterações do espermograma. C) Não há correlação significativa entre o diâmetro de um dos vasos dos plexos pampiniformes e o espermogramaINTRODUCTION: Varicocele is the dilatation of the veins of the pampiniform plexus of the testicle. The association between varicocele and infertility is diagnosed in 20 to 40% of the infertile men. Currently, in the ultrasound study of varicocele, the diameter of the veins is carried through with the patient in the supine position, before and during the Valsalva maneuver, taking the diameter of the veins consideration (> 0,20cm), and a more than 1 second bigger presence of reflux according to spectral Doppler study. OBJECTIVE: A) To consider a new methodology in the ultrasonographic evaluation of varicocele. B) To evaluate the agreement of the findings in the colorful Doppler ultrasonographic examination of the pampiniform plexus vases with the alterations in the spermogram in masculine infertility. C) To evaluate the correlation between the diameter of one the pampiniform plexus vases and the alterations in the spermogram in the masculine infertility. METHODS: 266 patients from the reproduction sector human being of the Hospital of the Clinics of the University of São Paulo (HCUSP) had been examined, by means of colorful duplex-Doppler, initially with the patient in dorsal decubitus and later, after 5 minutes, in the orthostatic position, carrying through the transversal measures of the diameter of the pampiniform plexus in the two positions, in rest and in Valsalva. To the pulse study reflux was considered pathological only when persisted for more than 1 second, with speed superior to 2 cm/s. These patients were also submitted to seminal analysis. RESULTS: Regarding the methodology of accomplishment of the examination, an increase in the diameter of pampiniform plexus was noted only with the variation of the examination position, about 18% to the right and 5,9% to the left, as well as an increase in the detection of venous reflux in the orthostatic position, 23% to right and 6,8% to the left. It was also detected a correct correlation between variations in the spermogram and the venous reflux, 65% to the right and 86% to the left, the same not occurring with the diameter of pampiniform plexus. CONCLUSIONS: A) The colorful Doppler ultrasound examination must be carried through in the orthostatic position, after a period of latency of at least five minutes, with comfortable environement conditions and effort maneuver. B) A significant accordance between the pampiniform plexus venous reflux and the alterations of the spermogram. C) It does not have significant correlation between the diameter of one of the pampiniform plexus vases and the spermogram