Дисертації: "NBFC"

1

Lemos, Renata Tavares da Silva. "Convergência NBIC." Florianópolis, SC, 2008. http://repositorio.ufsc.br/xmlui/handle/123456789/91075.

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Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-graduação em Engenharia e Gestão do Conhecimento
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Este trabalho trata do processo de convergência tecnológica NBIC (Nano-Bio-Info-Cogno), o qual é apresentado como processo transdisciplinar com implicações ontológicas e epistemológicas no conjunto da teoria do conhecimento. A característica transdisciplinar é determinada pela convergência de campos do conhecimento até então distintos, como os estudos biológicos, informacionais e cognitivos, que passam a interagir através da nanotecnologia. Esta interação convergente é a base do conceito de unidade da matéria, o qual refere-se à manipulação da matéria em escala nanométrica, permitindo a integração de sistemas biológicos e tecnológicos em sistemas híbridos. As tecnologias convergentes trazem implicações éticas e suscitam o surgimento de novas ontologias. A convergência tecnológica é também epistemológica, pois integra diversas epistemologias gerando novos espaços de intersecção entre as áreas do conhecimento, que por sua vez dão origem a ontologias emergentes. Situando-se metodologicamente na dinâmica de mudança conceitual de Paul Thagard e no método abdutivo de Peirce, este trabalho efetua uma análise teórica das relações conceituais entre a unidade da matéria e a unidade do conhecimento. A constatação fundamental é a de que a informação, organizada e distribuída de forma complexa em diversas estruturas e sistemas, pode ser encontrada em todos os níveis da natureza e do ser humano, confirmando o conceito de unidade da matéria pela constatação e estabelecimento de fluxos informacionais ubíquos desde o nível quântico. Os fluxos informacionais são os principais agentes da unidade do conhecimento. Os conceitos de informação e significado, analisados de forma sistêmica, emergem no contemporâneo como os principais elementos de re-ligação entre as diferentes áreas do conhecimento e suas respectivas epistemologias. Portanto, a consiliência em NBIC é informacional, sistêmica e semiótica. Conhecer as dinâmicas da informação e do conhecimento é também conhecer a essência ontológica da realidade. This work concerns the process of NBIC (Nano-Bio-Info-Cogno) convergence, which is hereby presented as a transdisciplinary process having epistemological and ontological consequences within a general theory of knowledge. This transdisciplinary character is established through the convergence of fields of knowledge that were, until now, distinct; such as the fields of biology, information technology and cognitive sciences, which are now interacting due to nanotechnologies. This converging interaction is the basis of the concept of unity of matter, which refers to the manipulation of matter at the nano scale, allowing the integration between biological and technological systems within hybrid systems. Converging technologies have ethical implications and originate new ontologies. We observe that convergence is also epistemological, because it encompasses various epistemologies, giving rise to new spaces of intersection between different areas of knowledge, which give rise to emerging ontologies. Consilience in NBIC is informational, systemic and semiotic; because the concepts of information and meaning, when subject to a systemic inquiry, emerge as the main elements connecting various areas of knowledge and their epistemologies. Using as our main methodology Paul Thagard´s dynamics of conceptual change and Peirce´s abduction method, we analyze the theory arising within the conceptual relations between unity of matter and unity of knowledge. Our main conclusion is that information, distributed and organized in complex systems and structures, can be found in every level of nature and humanity, confirming the concept of unity of matter by the acknowledgement and establishment of ubiquitous information flow from quantum levels. Information flow is the main agent of consilience. Knowing the dynamics of information and knowledge is knowing the ontological essence of reality.

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2

Santos, Thais da Silva. "Micro-nanocompósitos de Al2O3/ NbC/ WC e Al2O3/ NbC/ TaC." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/85/85134/tde-10022015-104122/.

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Cerâmicas à base de alumina pertencem à classe de materiais denominados estruturais, muito utilizados em ferramentas de corte. A alumina possui boas propriedades para uso como cerâmica estrutural e com o objetivo de melhorar suas tenacidade à fratura e resistência mecânica, são produzidos compósitos com diferentes aditivos. Novos estudos apontam para os micro-nanocompósitos, onde a adição de partículas micrométricas deve auxiliar no aumento da resistência mecânica, e de partículas nanométricas, no aumento da tenacidade à fratura. Neste trabalho foram obtidos micro-nanocompósitos à base de Al2O3 com inclusão de partículas nanométricas de NbC e micrométricas de WC com proporções de 2:1, 6:4, 10:5 e 15:10 e micro-nanocompósitos à base de Al2O3 com inclusão de partículas nanométricas de NbC e micrométricas de TaC com proporção de 2:1 em relação à alumina. Para o estudo de densificação, os micro-nanocompósitos foram sinterizados em dilatômetro com taxa de aquecimento de 20 °C / min até a temperatura de 1800 °C, em atmosfera de argônio. Com base nos resultados de dilatometria, corpos de prova foram sinterizados entre 1500°C e 1700°C, com patamar de 30 minutos, em forno resistivo de grafite e atmosfera de argônio. Foram determinadas as densidades, fases cristalinas formadas, durezas e tenacidades, e analisadas as microestruturas dos micro-nanocompósitos. As amostras Al2O3:NbC:TaC sinterizadas a 1700°C atingiram as maiores densidades aparentes (~95%DT) e a amostra sinterizada a 1600°C apresentou microestrutura homogênea e valor de dureza (15,8 GPa) em comparação à alumina pura. As composições com 3% de inclusões são as mais promissoras para aplicações futuras como ferramentas de corte.
Alumina based ceramics belong to a class of materials designated as structural, which are widely used in cutting tools. Although alumina has good properties for application as a structural ceramics, composites with different additives have been produced with the aim of improving its fracture toughness and mechanical strength. New studies point out micro-nanocomposites, wherein the addition of micrometric particles should enhance mechanical strength, and nano-sized particles enhance fracture toughness. In this work, alumina based micro-nanocomposites were obtained by including nano-sized NbC and micrometer WC particles at 2:1, 6:4, 10:5 and 15:10 vol% proportions, and also with the inclusion of nano-sized NbC and micrometer TaC particles at 2:1 vol% proportion. For the study of densification, micro-nanocomposites were sintered in a dilatometer with a heating rate of 20°C/min until a temperature of 1800°C in argon atmosphere. Based on the dilatometry results, specimens were sintered in a resistive graphite furnace under argon atmosphere between 1500°C and 1700°C by holding the sintering temperature for 30 minutes. Densities, crystalline phases, hardness and tenacity were determined, and micro-nanocomposites microstructures were analyzed. The samples Al2O3: NbC: TaC sintered at 1700 ° C achieved the greater apparent density (~ 95% TD) and the sample sintered at 1600 ° C showed homogeneous microstructure and increased hardness value (15.8 GPa) compared to the pure alumina . The compositions with 3% inclusions are the most promising for future applications.

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3

SANTOS, THAIS da S. "Micro-nanocompósitos de Al2O3/ NbC/ WC e Al2O3/ NbC/ TaC." reponame:Repositório Institucional do IPEN, 2014. http://repositorio.ipen.br:8080/xmlui/handle/123456789/23599.

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Dissertação (Mestrado em Tecnologia Nuclear)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

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4

Meyer, Donald Carl. "The NBC Symphony Orchestra /." Ann Arbor (Mich.) : UMI, 2005. http://catalogue.bnf.fr/ark:/12148/cb400361522.

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Jansson, Dan. "Telematik - en del i NBF? :." Thesis, Försvarshögskolan, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:fhs:diva-1766.

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Samhällsutvecklingen går från industrisamhälle till informationssamhälle och Försvarsmakten (FM) går fråninvasionsförsvar till insatsförsvar. Tidigare var det mer regel än undantag att civil teknologi hade sitt ursprung imilitär teknologi, t.ex. Internet. Idag är det precis tvärtom med marknadskrafterna som driver utvecklingen avt.ex. IT i ett högt tempo. Väpnade styrkor strävar efter att ta till vara på denna utveckling inom kommunikationoch informationsteknologi, i syfte att ha förmåga att möta framtida hot. Den militära utvecklingen inom dettaområde benämns Revolution in Military Affairs (RMA). Den svenska FM:s motsvarighet benämnsnätverksbaserat försvar (NBF) och är en tillämpning av tankegångarna kring konceptet RMA. Omfattandeforskning pågår inom IT generellt och telematiken är inte undantagen.Det amerikanska dokumentet Joint Vision 2010 FOCUSED LOGISTICS menar att teknologiutvecklingkommer att spela en avgörande roll för logistikledning, och att förbättringar av bl.a. built in test (BIT) ochtelemaintenance kommer att höja den tekniska personalens effektivitet. Telemaintenance är en delmängd avbegreppet telematik och består av: Fordonstjänster innehållande diagnostik för övervakning avfordonssystemet, larm för påkallning om allvarliga fel håller på att uppstå samt ”Vehicle Control” förfjärrstyrning av fordons funktioner. Underhållstjänster innehållande driftsinformation om t.ex. antaldriftstimmar, bränsleförbrukning, vibration, etc. Tjänsterna undersöks i denna uppsats med bakgrund avteknisk tjänst, vars syfte är att understödja krigsförbandens förmåga att lösa sina uppgifter. Teknisk tjänstbidrar till teknisk och taktisk tillgänglighet genom att säkerställa att ett tillräckligt antal materielsystem kanverka med erforderlig effekt.Uppsatsen tydliggör förväntningar på ett telemaintenance-system hos svensk trupp insatta i internationellaoperationer, närmare bestämt vilket behov av telemaintenance som 1993 förelåg vid den första bataljonen(BA01) som sattes in i Bosnien ingående i UNPROFOR.
As our industrial society has become more information based, ournational defense requirements have changed focus from an invasion defenceto an operations defence. For many years, new information technologiessuch as the internet were first developed for military use. Today the oppositeis true. Market forces are now driving the development of new technologiessuch as IT, at a fast pace. Armed forces must strive to make use of thesedevelopments within the areas of communication and informationtechnology, to better prepare for future threats. The military development inthis sector in called a “Revolution in Military Affairs” (RMA). The SwedishArmed Forces equivalency is called a “network-based defense” (NBF) andmakes use of the RMA concept. Extensive research is underway within ITin general and telematics is not an exception.The American document, “Joint Vision 2010 FOCUSED LOGISTICS”claims that the development of technology will play a decisive part inlogistics management, and that improvement in among other things, BITand telemaintenance will raise the effectiveness of technical servicepersonnel. Telemaintenance is one part within the concept of telematics andconsists of:Vehicle service consisting of diagnostic surveillance of vehicle systems,alarms for indication of serious faults, and Vehicle Control for remotecontrolling of vehicle functions.Maintenance service consisting of operational information such as thenumber of hours in operation, fuel consumption, vibration etc.Telemaintenance is investigated in this thesis with a background ofSwedish Army maintenance concept, which purpose is to support militaryfield units in their ability to solve their tasks. The maintenance conceptoffers greater technical and tactical availability by keeping optimal numbersof material systems operational.This thesis describes the expectations of a telemaintenence system of aSwedish troop in international operation, or more precisely, thetelemaintenence needs that were evident in 1993 at the first battalion(BA01) in Bosnia as part of UNPROFOR.
Avdelning: ALB - Slutet Mag 3 C-upps.Hylla: Upps. ChP 01-03

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Martin, Tracy Lee. "Evaluation of the Next Birth After Caesarean (NBAC) clinic." Thesis, Curtin University, 2012. http://hdl.handle.net/20.500.11937/1109.

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Developing, implementing and evaluating models of care that reduce the caesarean section (CS) rate have been a health care priority in Australia since the 1990’s. There is minimal evidence examining models of care that aim to nurture women’s emotional well-being after CS; as well as providing consistent evidence-based information and promoting safe and successful vaginal birth in the subsequent pregnancy. Furthermore the experiences of midwives working in these models have been overlooked.

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Williams, J. T. "Physiological considerations of NBC protective clothing." Thesis, Cranfield University, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.239749.

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Chifflet, Stéphanie. "Le récit de la convergence NBIC : vers une nouvelle cosmogonie ?" Grenoble 3, 2008. http://www.theses.fr/2008GRE39058.

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Les discours portés sur la convergence NBIC (convergence des nanotechnologies, biotechnologies, technologies de l'information et des sciences cognitives) relèvent d'une dimension symbolique et restent tributaires d'une pensée mythique héritée. Pour saisir tous les enjeux profonds des nouvelles technologies, il est indispensable d'en connaître les ressorts imaginaires. En effet, les sciences et les techniques (ce que nous appelons technologies) sont constituées, comme toute praxis humaine, d'images et de désirs ambivalents. En adoptant une vue sur le long terme et en inscrivant le domaine technologique dans l'histoire culturelle de la longue durée, nous tentons, dans le présent travail, de définir les contours d'un imaginaire technologique en cours de construction. La mise en récit de la convergence NBIC (qui est également une mise en images) est le lieu de réminiscences mythiques. Bien plus, selon nous, le "grand récit" de la convergence NBIC (elle-même présentée comme une révolution paradigmatique) est une actualisation du mythe cosmogonique. Par ces thèmes principaux (la maîtrise et la manipulation de la matière, la transformation de l'homme, l'héroïsation du scientifique, l'immortalité) le récit NBIC apparaît comme l'expression moderne d'un défi démiurgique que l'homme est invité à relever, devenant lui-même l'acteur d'une nouvelle religion : la religion de la technologie
Discourses about NBIC convergence (convergence between nanotechnology, biotechnology, information technology and cognitive science) have a symbolic dimension and depend on an inherited mythic thought. In order to strike the underlying stakes of new technologies, it is essential to know their imaginary aspects. Indeed, sciences and technics (what we call technologies) are constituted, like every human praxis, by ambivalent images and desires. By adopting a long term view and positioning the technological domain in the long cultural history, we try, in this work, to define the outlines of a technological imagination in progress. The NBIC convergence narration (which is also a game of images) brings about mythical reminiscences. Moreover, in our opinion, the "great story" about NBIC convergence (which is presented like a paradigmatic revolution) is an actualization of the cosmogonic myth. With its main themes (mastery and manipulation of the matter, human transformation, portraits made of scientists as new heroes, immortality), NBIC story appears like the modern expression of a demiurgic challenge that the mankind is tempted to take up, becoming himself the actor of a new religion: the technological religion

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Arnell, Krister. "NBF : en självsynkroniserande myt eller ett organiserat paradis?" Thesis, Försvarshögskolan, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:fhs:diva-1553.

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Det nätverksbaserade försvaret (NBF) är en vision som kommer att ställa många nya krav. Såväl rent tekniskasom organisatoriska. För mig har de organisatoriska aspekterna av NBF varit av särskilt intresse. När jaghar tagit del av skrifter och samtal rörande det nätverksbaserade försvaret har jag speciellt fäst mig vid att detibland framkommer att en självsynkroniserande organisation skulle vara det optimala slutmålet. Jag har självtjänstgjort inom olika befattningar inom flygvapnets ledningssystem, först STRIL – 60 och sedan Flygvapnet2000. De erfarenheter jag själv har gjort under min tid i Flygvapnet har lett mig fram till slutsatsen att själsynkroniseringvar den sämsta tänkbara av reservnivåer. För att komma lösning på gåtan om organiseringsproblematikennärmare har jag med utgångspunkt från teorier om organisatoriska framgångsfaktorer valt attgenomföra ett antal simuleringar. Jag har vid två tillfällen simulerat ett luftförsvarsscenario, vid dessa tvåtillfällen användes två olika uppsättningar av deltagare. Vid första simuleringstillfället gavs deltagarna tydligaroller och arbetsbeskrivningar, i denna uppsats kallade ”Beslutsregler”. Vid det andra tillfället fick deltagarnaendast en roll tilldelad, de fick sedan utifrån sina tidigare erfarenheter forma dessa roller. Vid varjetillfälle har det dessutom gjorts två delsimuleringar med skilda organisatoriska och tekniska förutsättningar.De kategorier av personal som funnits med under simuleringarna är, flygförare, flygstridsledare, chefsflygstridsledareoch luftförsvarsledare. Vid båda tillfällena fick deltagarna i uppgift att luftförsvara Stockholm.För att mäta effektskillnader i vad de olika organisationerna lyckades uppnå vid de olika simuleringstillfällenaså erhölls poäng för varje mål deltagarna lyckades bekämpa. Målen i scenarierna har haft olika poängvärdeberoende på om de har varit på väg mot Stockholm eller andra geografiska områden, där målen motStockholm gett högst poäng. Vid analys av slutresultaten framkommer en del mycket intressanta skillnaderpå vad de olika organisationerna lyckades åstadkomma och även hur de agerade, bl.a. visade det sig att centraliseradledning inte alltid är av ondo.
During my career in the Royal Swedish Air Force I have served in several different positions,amongst them I can mention the ones as weapons controller and fighter allocater.During the recent years, I have through the reading of different books and discussionswith my colleagues, encountered the opinion that self-synchronised organisationswould be the ultimate goal when organising Network Centric Warfare. My own experiencewas that this was the last option used after everything else had failed. In Swedishlitterateur regarding Network Centric Warfare, you can see the expression of a will to beable to change command philosophy from centralised command to a decentralised anddelegated (Auftragstaktik) command. In this essay I have examined the effectiveness oftwo different organisations, the first one more like a classic hierarchic organisationcomplemented with rules regarding responsibilities for each participant. The participantsin the second organisation only got a role and then had to fulfil this role drawingon their previous experience from working in the Air Force. The participants were allAir Force officers and each one of them could only participate in one of the organisations.The organisations were then tasked to carry out counter air operations in a simulator.Their only mission during the simulations was to protect the city of Stockholm. Inthe simulation the participants met a pre-recorded adversary, for the elimination of atarget the organisations were awarded points. The target heading towards Stockholmearned each organisation more points then other targets. The accumulated points thengave a rating for their effectiveness. The result was then analysed with the help of theoriesregarding what is needed for organisational success and theories regarding networkorganisations. The conclusions clearly state that the organisation with the rules achieveda better result, especially when the technical conditions degenerated. This organisationeven succeeded to improve their result with degraded technical conditions, the otherorganisation got a lower result during the same circumstances. One of the main reasonsthe organisation who had to rely on their previous experience from the Air Force nevergot up to the same standard as the other organisation, was due to the fact that they hadto spend more time to get them selves organised. Furthermore my examination showsthat networks are very complex and hard to overlook for an individual person. Thisleads to problems when you want to communicate in the network and also severe problemswhen it comes to optimizing the efficiency of the network.
Avdelning: ALB - Slutet Mag 3 C-upps.Hylla: Upps. ChP 03-05

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Reinhold, Tore. "Ad hoc-nät - något för mobila enheter i NBF?" Thesis, Försvarshögskolan, 2002. http://urn.kb.se/resolve?urn=urn:nbn:se:fhs:diva-1882.

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Ett syfte med nätverksbaserat försvar är att erhålla snabbare reaktionstider i ledningssystem.Ad hoc-näten utgör en framtida möjlighet att erbjuda taktiskt rörliga enheteruppkoppling i nätverk även under förflyttning. Det kan på sikt inkludera de funktionersom har krav på liten fördröjning i uppkopplingarna. Exempel på en sådan funktion ärsensorintegration genom sensornät. Ett av problemen i ad hoc-nätverksutvecklingenligger i att de dataprotokoll som ska utnyttjas för att erbjuda en kompabilitet mot denfasta nätstrukturen, inte har den funktionsduglighet som krävs i ett ad hoc-nät. För att gesnabb överföring krävs en utvecklad variant av de nätverksprotokoll (TCP/IP) somhanterar uppkomna fel på förbindelsen. Detta är avgörande för ad hoc-nätverkensfunktionsduglighet. Det skulle resultera i minskade fördröjningar och därmed ökadkapacitet. Mycket talar för att snabbheten kommer att bli så stor att multisensordatafusionkan realiseras i ad hoc-nät.
Avdelning: ALB - Slutet Mag 3 C-upps.Hylla: Upps. ChP T 00-02

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Silva, Paula Fernanda da. "Desgaste e fadiga térmica de ligas \'aço matriz + NbC\'." Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/3/3133/tde-13032007-170403/.

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Utilizou-se o conceito de ?aço matriz + NbC? para produzir ligas com a matriz do aço rápido M2 ( 0,5%C ? 2%W ? 3%Mo ? 4,6%Cr ? 1%V) e variadas frações volumétricas de carbonetos de nióbio. Adicionou-se 2,5 e 5% de nióbio e carbono estequiométrico para a obtenção de carbonetos NbC e titânio (0,1%) para modificação da morfologia dos carbonetos NbC. Os carbonetos NbC apresentaram-se como carbonetos eutéticos com morfologia de escrita chinesa, como carbonetos primários com a morfologia de cruz de malta e como carbonetos eutéticos e primários com morfologia poligonal, estes últimos modificados com a adição de titânio. Após tratamento térmico de têmpera e revenimento para obtenção da máxima dureza, as ligas foram submetidas a ensaios de fadiga térmica (100 ciclos, 650ºC), de abrasão (roda de borracha ? 130N, 200rpm, 30min, hematita como abrasivo) e de deslizamento alternado (disco contra esfera ? 70,6N, amplitude: 6mm, freqüência, 6 Hz, 2h) para estudar o efeito da fração volumétrica e da morfologia dos carbonetos frente a estas solicitações. As ligas com carbonetos com morfologia poligonal e menor fração volumétrica de carbonetos (comparando-se morfologias iguais) apresentaram o melhor desempenho sob fadiga térmica devido ao baixo valor do parâmetro C/Dm da microestrutura (continuidade de carbonetos/distância livre média entre carbonetos). Os corpos-de-prova foram caracterizados por meio de microscopia ótica e eletrônica de varredura para determinar os sítios de nucleação e caminhos de propagação das trincas. Nos ensaios em roda de borracha as ligas com carbonetos eutéticos divorciados com morfologia poligonal apresentaram maior resistência ao desgaste do que os aços contendo carbonetos eutéticos cooperativos. O aumento da fração volumétrica de carbonetos NbC teve um máximo na resistência a abrasão e depois uma queda devido a presença de carbonetos primários grosseiros que fraturaram na superfície ensaiada e foram arrancados aumentanto a perda de massa. Nos ensaios de deslizamento alternado não foi possível hierarquizar o comportamento das ligas. Os corpos-de-prova de abrasão e de deslizamento foram caracterizados por microscopia ótica e eletrônica de varredura para determinar os mecanismos de desgaste atuantes. Um aço rápido para cilindros de laminação a quente (2%C ? 5%Cr ? 5%Mo ? 5%V) foi ensaiado sob condições idênticas às aplicadas às ligas estudadas, objetivando comparar desempenhos. O aço rápido apresentou desempenho superior nos ensaios de abrasão e de deslizamento alternado (devido a alta fração volumétrica de carbonetos eutéticos) e inferior no ensaio de fadiga térmica (devido ao alto parâmetro C/Dm da microestrutura oriundo da alta fração volumétrica de carbonetos eutéticos).
The concept of ?matrix steel + NbC? was used to cast alloys with the M2 steel matrix (0,5%C ? 2%W ? 3%Mo ? 4,6%Cr ? 1%V) and different volume fractions of niobium carbides. Niobium (2,5 e 5%) and stoichiometric carbon were added to produce NbC carbides and titanium (0,1%) to modify de NbC carbides morphology. NbC presented three basic morphologies: Chinese script (coupled eutectic); primary carbides with cross morphology and polygonal primary and eutectic carbides (divorced eutectics). After heat treatment of quench and temper in order to obtain the maximum hardness, the alloys were submitted to thermal fatigue test (100 cycles, 650ºC), dry rubber wheel abrasive wear test (130N, 200rpm, 30min, hematite as abrasive) and reciprocating sliding wear test (70,6N, amplitude: 6mm, frequency: 6Hz, 2h). The alloys with polygonal NbC carbides and lower volume fractions of carbides (for the same morphology) showed the best behaviour due to their low ?carbide continuity/carbide free path? ratio of the microstructure. The alloys were characterized by optical microscopy and SEM to investigate de cracks nucleation and propagation. In the dry rubber wheel tests, polygonal NbC eutectic carbides (divorced eutectics) showed better behaviour than Chinese script NbC eutectic carbides. High volume fractions of NbC carbides improved the abrasion resistance until a maximum and after that, the presence of big primary NbC carbides, lowered the abrasion resistance due to cracks in those big carbides. The results of the reciprocating sliding tests have not allowed to rank the performance of the alloys. Abrasion and sliding specimens were submitted to optical microscopy and SEM in order to evaluate the prevalent wear mechanisms. One high speed steel for hot rolling mill rolls (2%C ? 5%Cr ? 5%Mo ? 5%V) was tested under the same conditions that the alloys studied were tested in order to compare their performances. The high speed steel showed better performance in abrasion and reciprocating sliding wear due to the high volume fraction of coupled eutectic carbides and lower performance in thermal fatigue due to the high ?carbide continuity/carbide free path? ratio of the microstructure than the alloys studied.

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Ferreira, Vanderlei. ""Processamento, Caracterização Mecânica e Tribológica do Compósito Al2O3-NbC."." Universidade de São Paulo, 2001. http://www.teses.usp.br/teses/disponiveis/85/85134/tde-17122001-143416/.

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Neste trabalho foi investigado o processamento e propriedades mecânicas e tribológicas do compósito cerâmico Al2O3- NbC com o objetivo de desenvolver um compósito cerâmico com melhores propriedades do que a alumina pura. Como material para comparação foi utlizado a alumina que é uma cerâmica tradicionalmente aplicada onde é necessária elevada resistência mecânica e ao desgaste. A composição Al2O3-0,5%wtY2O3-20%wtNbC, que origina o compósito, passou por moagem e mistura em moinho tipo atrittor e secagem em evaporador rotativo. O pó obtido foi caracterizado quanto a distribuição granulométrica e morfologia. A alumina seguiu a rota tradicional de moagem e mistura em moinho de bolas, secagem em spray dryer; e mesma caracterização realizada para o compósito. Foi realizado estudo da sinterização em dilatômetro para os dois materiais com intuito de determinar as condições ideais de sinterização. Por meio de prensagem uniaxial seguida de prensagem isostática a frio foram confeccionadas amostras na forma de discos e pinos. Os materiais densos foram obtidos por sinterização normal sendo que a alumina ao ar e o compósito em atmosfera de argônio. As fases formadas no dois materiais foram determinadas por difração de raios X. As microestruturas foram estudas em microscópio eletrônico de varredura nas superfícies polidas e atacadas. Entre as propriedades mecânicas foram medidas o módulo elástico, a dureza e a tenacidade à fratura por meio de impressões Vickers. O compósito desenvolvido apresentou valores superiores em todas estas propriedades em relação a alumina. O estudo do comportamento tribológico foi realizado por meio do deslizamento de pinos, com extremidade cônica, de alumina e do compósito cerâmico sobre discos de alumina. Os ensaios foram realizados com a velocidade de 0,4m/s e com carregamento, por meio de peso morto, de 10N sob diferentes níveis de umidade relativa ( 26,8; 48 e 76,3%). O coeficiente de atrito cinético médio, assim como a taxa de desgaste, diminuiu em todos os ensaios com o aumento da umidade relativa, para os dois materiais. Este comportamento foi relacionado com a formação de uma camada na interface de contato entre as superfícies do pino e do disco de hidróxido de alumínio. O compósito demostrou maior resistência ao desgaste em todas as condições tribológicas estudadas. O compósito cerâmico desenvolvido claramente possui boas perspectivas como um novo material cerâmico em importantes aplicações técnicas.
In the present work processing, and mechanical and tribological properties of a ceramic composite Al2O3-NbC were investigated in order to develop a ceramic material with superior properties. Alumina was chosen as a reference since it is a traditional ceramic material for applications where elevated mechanical properties and wear resistance are required. The composition Al2O3 - 0.5 wt%Y2O3-20 wt%NbC was prepared by attrition milling followed by drying in a rotaevaporator. The resulting powder mixture was characterized for granulometry and powder particles morphology. Alumina was processed according to the traditional route of ball milling followed by passing through a spray drier, and the processed powder was then characterized the same way as the composite. Dilatometry was accomplished for both materials in order to define the ideal sintering conditions. Samples with the shape of discs and pins were compacted by uniaxial pressing followed by cold isostatic pressing. Densification was achieved by sintering in air and in argon for alumina and the composite, respectively. Phase composition of sintered materials was studied by X-ray diffraction (XRD). Microstructure was investigated by means of scanning electron microscopy (SEM) on polished and etched surfaces. Materials were also characterized for a number of mechanical properties, in particular for Young modulus, hardness, and fracture toughness by Vickers indentation method. The developed composite exhibited superior mechanical properties as compared to alumina. Tribological behavior was investigated by means of a sliding pin on disk test with pins of a conical shape prepared both from alumina and the composite, and an alumina disk. Tests were performed with the sliding speed of 0.4 m/s and 10N load under varying humidity conditions (26.8; 48, and 76.3%). Both the mean coefficient of friction and the wear rate diminished in all tests with the increase of humidity for both materials. Such behavior was attributed to a aluminum hydroxide layer formation between the pin and the disk surfaces. The developed composite exhibited better wear resistance under all tribologic conditions studied. The developed ceramic composite obviously has good perspectives as a new material for a variety of important technical applications.

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13

Labonne, Mathilde. "Frittage et évolution microstructurale de carbures cémentés NbC-Ni." Thesis, Université Grenoble Alpes, 2020. http://www.theses.fr/2020GRALI056.

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Depuis plus de 70 ans, les carbures cémentés WC-Co sont utilisés mondialement dans de nombreuses applications telles que l'outillage, les équipements miniers, ou encore les pièces d'usure. Cependant, il a récemment été déterminé que les oxydes de cobalt et de tungstène peuvent présenter des risques pour la santé. De plus, la demande mondiale de tungstène et de cobalt n’a cessé d’augmenter au fil des ans, entrainant de régulières hausses des prix. Ce contexte défavorable encourage les entreprises à développer des matériaux à base de carbures alternatifs. Les carbures de niobium sont notamment de plus en plus envisagés. Bien que possédant une dureté légèrement inférieure à celle des carbures de tungstène, ils sont deux fois moins denses et présentent une excellente résistance à l’usure. De plus, aucun risque pour la santé n’a été identifié pour le niobium métallique, les carbures de niobium ou les oxydes de niobium. Les études précédentes portant sur les matériaux à base de NbC se sont principalement intéressées aux microstructures obtenues et aux propriétés mécaniques, notamment la dureté, la ténacité et les propriétés de résistance à l'usure. Cependant, le frittage et les mécanismes de croissance des grains n'ont pas encore été entièrement étudiés. Cette étude vise à analyser le comportement en frittage et la croissance de grains d’alliages NbC-Ni, ainsi que l’effet de l’ajout de carbures secondaires. Il a dans un premier temps été déterminé que le taux de carbone dans les carbures a un impact significatif sur le frittage et la microstructure. En particulier, l'augmentation du taux de carbone entraîne une diminution de la contiguité de la phase carbure. L'ajout de carbures secondaires entraine un retard du frittage en phase solide, une augmentation de la contiguité de la phase carbure et limite la croissance des grains. Enfin, une partie importante de cette étude porte sur l’étude des mécanismes de croissance. En combinant des théories classiques de croissance et un modèle simplifié, il a été estimé que la cinétique de croissance est contrôlée par une migration coopérative des joints de grains et des joints de phases
For more than 70 years, WC-Co materials have been used worldwide for numerous applications in tooling, mining equipment or wear parts. Unfortunately, it has been recently determined that the cobalt and tungsten oxides present risks and health issues. Furthermore, the worldwide demand for tungsten and cobalt has been continuously growing, although the mining stocks of both elements are limited, which increased their price over the years. This global context has led industrial companies to investigate alternative carbide based materials. Niobium carbides are increasingly considered to replace tungsten carbides for specific applications. Although those carbides present a slightly lower hardness, they have impressive wear properties and are twice less dense than WC. Furthermore, no particular health hazards were identified for the use of bulk metallic niobium, niobium carbides and niobium oxides. Previous studies of NbC based materials have mostly focused on their microstructures and the resulting mechanical properties, notably the hardness, toughness and wear properties. However, the sintering process of niobium carbide based cemented carbides and the carbide grain growth mechanism involved have not yet been fully investigated. The present study aims to analyze the sintering behavior and grain growth of NbC-Ni materials and the effect of secondary carbides addition. It was first determined that the carbon content has a significant impact on the sintering behavior and the microstructural evolution. Notably, increasing the carbon content decreases the carbide phase contiguity. The addition of secondary carbides leads to a delay of solid state sintering and limits grain growth. The contiguity increases with these additions. Finally, a particular focus was made on grain growth mechanism in such materials. By combining classic growth theories and a simplified model, it was estimated that growth kinetics are controlled by a cooperative migration of grain boundaries and phase boundaries

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14

Romano, Angelo. "Seismic response analysis of low-rise buildings designed according to the NBCC 1990." Thesis, McGill University, 1990. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=59378.

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An earthquake of magnitude 5.7 occurred in the Saguenay region of the province of Quebec, Canada, on November 25, 1988. Although no loss of life or severe structural damages were caused by this earthquake the poor performance of unreinforced masonry and structures with 'tension-only' cross-bracing were reported by a site visit team.
This thesis presents some of the important engineering characteristics of the 1988 Saguenay earthquake. Comparisons are made in terms of elastic and inelastic response spectra for the lateral forces to be considered for the seismic response analysis of short-period structural systems. In particular, the seismic response of a low-rise braced steel building designed according to the National Building Code of Canada is investigated in both the elastic and inelastic range.
The code-suggested equivalent lateral force method for short-period structures with a substantial strength-reduction factor does not provide a rational control of structural damage that can be expected from seismic excitation in Eastern Canada. The use of a period-dependent strength reduction factor applied to the elastic strength demand for short-period structures is proposed to take advantage of the inelastic energy dissipation capacity for this type of system on a more rational basis.

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15

Landgren, Ulf. "Nätverksbaserat försvar (NBF) - från tanke till koncept : en irrationell process?" Thesis, Försvarshögskolan, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:fhs:diva-1692.

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Den omvärldsförändring som skedde i och med Berlinmurens fall och upplösningen av Warszawapaktentillsammans med civil teknikutveckling under 1990-talet har bidragit till en nödvändigoch övergripande förändring av Försvarsmakten.Utvecklingen mot ett nätverksbaserat försvar är en av de största och mest omvälvande förändringarsom Försvarsmakten genomför i modern tid. Detta väcker tankar och funderingar kring hurNBF som idé dykt upp på den politiska och militära scenen i Sverige och hur den fortsatta övergripandeprocessen sett ut fram till och med försvarsbeslut 2001. Detta har i uppsatsen utvecklatstill två frågeställningar:• Hur initierades och etablerades NBF-konceptet på dagordningen och när i tiden skeddedetta?• Vilka politiska och militära händelser och beslut skall ses som avgörande under tidsperiodenfram till och med 2001 för utvecklingen av NBF-konceptet?
The purpose of this essay was to research why and how the Swedish version of networkcentric warfare (NCW) was initiated and processed in the political and military arena. Theessay was structured after a rational policy theory written by R Premfors. Four out of sevenphases from the theory were used; problem, alternatives, recommendation and decision.This work started with studies of official documents and publications and was followed bysix interviews with individuals who held important positions connected to the developmentof NCW. This work determined that the fall of the Berlin Wall and the dissolution of theWarsaw Pact, together with the development of civil technology in the mid 1990’s were allcontributors to a necessary change within the Swedish Armed Forces. Meetings betweenindividuals from Sweden and the US played an important role in initiating the process.Unofficial briefings to the Defence Secretary and decisions made by him played an importantrole later in the process. The development of the NCW was formalised with three parliamentbills. This work showed a defective rationality in the beginning of the process andlack of cohesion throughout the process.
Avdelning: ALB - Slutet Mag 3 C-uppsHylla: Upps. ChP 02-04

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Franco, Eliana. "Desenvolvimento de cermets e recobrimentos a base de nióbio para aplicações em ferramentas." Universidade do Estado de Santa Catarina, 2014. http://tede.udesc.br/handle/handle/612.

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Made available in DSpace on 2016-12-08T15:56:17Z (GMT). No. of bitstreams: 1 TESE_ ELIANA FRANCO.pdf: 10762116 bytes, checksum: 0473839f89cd4764137c8cf282af6c0d (MD5) Previous issue date: 2014-06-27
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Materials or coatings for tools are of primary importance for industrial development. This work proposes the development of tools materials through two routes, one of them using cermets based Fe-NbC as a raw material and the other through thermochemical treatments in steel tool substrates. The specific objectives were planning the processing, manufacture and analyze of Fe-NbC cermets; and to develop a coating composed by B, Nb and C by diffusion thermoreactive in solid-state in M2 high speed steel substrates. There are some studies, even applications of cermets using iron as a matrix, such as cermets with TiC or Ti (C, N) carbides. The Brazilian Society of Mining and Metallurgy (Companhia Brasileira de Metalurgia e Mineração - CBMM) produced the Fe-NbC cermets with different contents of Al and other elements added during the obtaining of cermets. In this work thermal analyzes and calculations of phases equilibrium were performed through ThermoCalc® software to study the thermal behavior of these materials. Also, C and Fe were added to these materials and consolidations by conventional powder metallurgy and by Field Assisted Hot Pressing (FAHP). The results showed that these cermets had a temperature of formation of liquid phase around 1200o C. The Fe and C addition resulted in the disappearance of undesirable phases. The cermet FeNbC5Al exhibited higher hardness with or without additions, 820 HV10 without additions elements and after consolidation by FAHP and annealing. For the development of surface coatings, multicomponent boriding with Nb treatments were performed on substrates of M2; treatments in stages, with diffusion of Nb and B separately; and simultaneous treatments, with diffusion of Nb and B at the same time. Treatments were carried out by the thermoreactive diffusion method on solid-state; calculations were made by ThermoCalc® to estimate the pack composition and treatment temperature. The results showed that by the treatment performed in stages, a coating formed by NbB and NbC phase with hardness 2300 HV was obtained. The wear volume of the material showed high dispersion of results, which can be improved by producing a more homogeneous niobized layer; a suggestion to obtain that layer is using a substrate with a small addition of alloying elements or niobizing in liquid bath.
O interesse por materiais ou recobrimentos para ferramentas é de suma importância para o desenvolvimento industrial. Este trabalho propõe o desenvolvimento de ferramentas através de duas rotas, uma utilizando como matéria prima cermets a base de Fe-NbC e outra por meio de tratamentos termoquímicos em substratos de aço ferramenta. Os objetivos específicos foram planejar o processamento, fabricar e analisar cermets Fe-NbC; e desenvolver um recobrimento a base de B, Nb e C por difusão termorreativa em meio sólido, em substratos de aço rápido M2. Há alguns estudos, e até mesmo aplicações de cermets que utilizam ferro como matriz, como os cermets com carbonetos de TiC ou Ti(C,N). A Companhia Brasileira de Metalurgia e Mineração (CBMM) produziu os cermets Fe-NbC com diferentes teores de Al, bem como outros elementos, adicionados durante a obtenção dos cermets. Neste trabalho realizaram-se análises térmicas e cálculos de equilíbrio de fases através do software ThermoCalc® para estudar o comportamento térmico destes materiais. Também se fizeram adições de C e Fe a esses materiais e consolidações por metalurgia do pó convencional e por compactação a quente assistida por campo (FAHP). Os resultados mostraram que esses cermets apresentaram uma temperatura de formação de fase líquida em torno de 1200o C. A adição de C e Fe resultou no desaparecimento de fases indesejáveis. O cermet FeNbC5Al exibiu maior dureza com ou sem adições, 820 HV10 sem adição de elementos e após consolidação assistida por campo e recozimento. Para desenvolvimento dos recobrimentos de superfície, realizaram-se tratamentos de boretação multicomponente com Nb sobre substratos de M2; tratamentos em etapas, com difusão de B e Nb separadamente; e tratamentos simultâneos, com difusão de B e Nb ao mesmo tempo. Realizaram-se os tratamentos pelo método de difusão termorreativa em meio sólido, se fizeram cálculos por ThermoCalc® para a estimativa da composição da mistura e temperatura de tratamento. Os resultados mostraram que através do tratamento em etapas, se obteve um recobrimento formado por fases de NbB e NbC com dureza de 2300 HV. O volume de material removido desse material apresentou alta dispersão de resultados, o que pode ser melhorado através da produção de uma camada niobizada mais homogênea; uma sugestão para obtenção de uma camada mais homogênea é através da utilização de um substrato com pouca adição de elementos de liga ou da realização de niobização em banho líquido.

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Dreshfield, David A. "Federal Regulation of Emerging Technologies and Its Implications for Transhumanist Applications of NBIC Technologies." Scholarship @ Claremont, 2012. http://scholarship.claremont.edu/cmc_theses/538.

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This paper attempts to chart potential courses for federal regulation of emerging technologies in the United States, and its near-future implications for the development and proliferation of NBIC technologies in a transhumanist context. Drawing on significant regulatory actions by the FDA and FCC throughout the twentieth century, relevant historical regulatory trends are identified and extrapolated broadly across the next two to three decades. The importance of the NBIC paradigm is discussed in detail, alongside several examples of both current and potential NBIC technologies with transhumanist applications. It ultimately concludes that, in spite of recent congressional dysfunctions and lack of political will, the groundwork that has already been laid by major federal regulatory agencies well in advance of the wide commercialization of NBIC products is a promising sign for the eventual establishment of responsible and flexible regulatory schema for NBIC technologies.

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Gao, Wei. "Oxidation of nitride-bonded silicon carbide (NBSC) and hot rod silicon carbide with coatings." Thesis, University of Strathclyde, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.366751.

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19

Åkerström, David. "Nätverksbaserat försvar : Då och Nu." Thesis, Försvarshögskolan, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:fhs:diva-4173.

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20

Mayrand, Basile. "Les nouvelles technologies au prisme de la notion de convivialité d'Ivan Illich." Thesis, Sorbonne université, 2019. http://www.theses.fr/2019SORUL054.

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En plus d’un siècle, la philosophie de la technique a pris un essor considérable. De nombreuses critiques sont venues récemment enrichir notre vision du progrès technologique. Cependant, malgré une grande effervescence intellectuelle autour de ces sujets, l’impact des réflexions philosophiques sur les nouvelles technologies est-il réel ? Cette thèse utilise la notion de convivialité, créée par Ivan Illich (1926-2002), pour interroger les nouvelles technologies. L’intérêt de cette recherche repose sur le présupposé selon lequel les technologies modernes, et les systèmes techniques qu’elles constituent, instancient des valeurs morales souvent de manière implicite. C’est pourquoi, tout au long de ce travail, nous défendons l’idée qu’il est erroné de considérer les nouvelles technologies comme de simples outils moralement neutres. La thèse s’articule autour des trois axes constitutifs du concept de convivialité : la survie, l’équité et l’autonomie créatrice. Nous montrons dans un premier temps en quoi les nouvelles technologies représentent plus un danger pour la survie qu’une opportunité. Dans un second temps, nous découvrons qu’elles menacent également le principe d’équité. Dans un troisième temps, nous démontrons que l’orientation actuelle du développement technologique s’inscrit bien souvent aux antipodes de l’autonomie créatrice. Néanmoins, cette tendance ne paraît pas irréversible par nature. L’espoir d’une réorientation, nous permet de conclure sur l’idée qu’une prise en compte effective de la convivialité dans la conception des nouvelles technologies passe vraisemblablement par l’institutionnalisation du concept, au risque de l’exposer à des effets de contre-productivité
For more than a century, philosophy of technology has grown significatively. Many critics have enriched our vision of technological progress. However, despite a contemporary intellectual effervescence on these subjects, is the impact of these philosophical reflections on new technologies real? This thesis uses the concept of conviviality, created by Ivan Illich (1926-2002) in the 1970s, to question new technologies, and specifically those often mentioned under the NBIC acronym (nanotechnology, biotechnology, information technology and cognitive science). The purpose of this research work is based on the philosophical premise that modern technologies, and the technical systems they constitute, instantiate moral values. Therefore, throughout this work, we defend the idea that it is wrong to consider new technologies as mere morally neutral tools. The thesis is articulated around the three axes constituting the concept of conviviality: survival, justice and self-defined work. We first show how new technologies are more a danger to survival than an opportunity. In a second step, we discover they also threaten the principle of justice as Illich conceives it. Thirdly, we show that the current direction of technological development is often at odds with self-defined work. However, this trend does not seem irreversible per se. The hope of reorientation allows us to conclude on the idea that an effective and sustainable consideration of conviviality in the design of new technologies would passes by the institutionalization of the concept, at the risk of exposing it to the effects of counterproductivity

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Hamberg, Ulf. "NBF- Förmågan att se på andra sidan kullen eller ”Kejsarens nya kläder"." Thesis, Swedish National Defence College, War Studies Division, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:fhs:diva-608.

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Анотація:

So- called “Network Based Defense” (NBD) was introduced in Sweden in connection with the transformation of the Swedish Armed Forces in 1999. NBD is based on the U.S. variant Network Centric Warfare (NCW), which in turn is derived from research on the concept of Revolution in Military Affairs (RMA). In Sweden the concept was introduced and included not only the Armed Forces but was intended to also support the Swedish civilian agencies in order to create networks and hence share the available information and thus more effective crisis management and to provide more "bang for the buck." In developing the concept of NBD the Swedish Armed Forces used both economic and human resources, in the form of research, new technologies, new organization and new methods.

Between year 2004 and 2006 the Armed Forces once again entered the process of reorganization. This time to “classic” military hierarchical organization and NBD as development engine disappeared due to economic cutbacks, together with the decision to participate in the European Union (EU) rapid reaction force. The purpose of this essay is to study the theories and ideas behind the concept and why the concept "disappeared" a few years later. The result of the work suggests that the concept of NBD in its abstract form was too theoretical. The process of organization introduced by HKV -04 is the clearest example of this abstract ambiguity concerning command and responsibility. Research suggests that responsibility is the basis of military organization and operations. The results also shows that a number of experiences from the development of the NBD has been used in the more practically oriented transformation of the Armed Forces necessary by the commitments for the so- called Nordic Battle Group (NBG-08).

The results have also shown correlation between NBD development and the increased Nordic cooperation in the form of sea and air surveillance and the well-developed body interaction within the framework of the national crisis management capacity in Sweden.

Nätverks Baserat Försvar (NBF) infördes i Sverige inom ramen för transformationen av Försvarsmakten från ett invasionsförsvar till ett insatsförsvar. NBF bygger på den amerikanska varianten Network Centric Warfare (NCW) som i sin tur härstammar från forskningen kring begreppet Revolution in Military Affairs (RMA). Konceptet infördes och innefattade inte bara Försvarsmakten utan även stödmyndigheter i syfte att skapa ett nätverk och därmed dela tillgänglig information och därmed effektivisera krishanteringen och ge mer ”pang för pengarna”. Kring utvecklingen av konceptet NBF lades stora resurser i form av forskning, ny teknik, ny organisation och nya metoder.

År 2004 till 2006 omorganiserades Försvarsmakten återigen från införd processorganisation enligt NBF till klassisk militär hierarkisk organisation och NBF som utvecklingsmotor försvann i och med ekonomiska neddragningar tillsammans med beslutet om att delta i Europeiska Unionens (EU:s) snabbinsatsstyrka.

Syftet med denna uppsats är att studera tankar och teorier som ledde fram till NBF och vad som kan vara en förklaring till att NBF försvann några år senare.

Resultatet av arbetet med uppsatsen tyder på att konceptet NBF i sin abstrakta form blev för teoretiskt. Den processorganisation som infördes med HKV -04 är det tydligaste exemplet på denna abstrakta oklarhet främst vad gäller befäl och därtill kopplat ansvar. Forskning pekar på att ansvar utgör grunden i militär organisation och verksamhet. Resultaten visar också på att de positiva lärdomarna från utvecklingen av NBF i form av vikten av ”nätverkande” låg som grund till det mer praktiskt inriktade transformeringen av Försvarsmaktens delar genom Nordic Battle Group, (NBG-08). Resultatet har också påvisat samband mellan NBF utvecklingen och det utökade nordiska samarbetet i form av sjö och luftövervakning samt den likaså utvecklade myndighetssamverkan inom ramen för den nationella krishanteringsförmågan i Sverige.

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Stark, Olof. "Markmålsrobot på svenska örlogsfartyg i NBF-miljö : politisk vilja och militär förutsättning." Thesis, Försvarshögskolan, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:fhs:diva-1825.

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Operationer, operativ ledning, nätverksbaserat försvar och manöverkrigföring ärnågra av ledorden i dagens alltmer kvalitativa försvar. Dessa uttryck är även viktigadå nya förmågor som robotsystem med markmålskapacitet diskuteras. Dessutommåste politisk vilja och militär förutsättning finnas för att dessa system skall bli förverkligade.Arbetet undersöker om det finns politisk vilja och militära förutsättningarför markmålsrobotar placerade ombord på morgondagens svenska örlogsfartyg. Föratt det skall bli förståeligt innehåller arbetet dessutom en kortfattad beskrivning avdylika befintliga, och tänkta framtida, robotsystem. Vidare belyser arbetet hur systemenkan kopplas ihop med de svenska operativa ledningsfilosofierna och kopplasslutligen mot de militära operativa imperativen. Uppsatsen teorianknytning är teoriernakring manöverkrigstänkandet och det nätverksbaserade försvaret.
Historical Sweden has had the ability to conduct Naval Gun Support (NGS).Particularly with armoured vessels ore ironclads as they were called. Later oncruisers and destroyers solved the task. From the middle of the eighties up topresent time Sweden’s naval register of shipping have consisted of smallerunits without the capability of Naval Surface Fire Support (NSFS) that is thecurrent used term.Technological evolution up until today enables smaller vessels (surface-shipsand conventional submarines) to carry arms such as Standoff Land AttackMissiles (SLAM). This fact together with the theories about network centricwarfare and manoeuvre warfare facilitates the base of this work.Operations, operational command, network centric warfare and manoeuvrewarfare are some keywords in today’s quality based defence forces. Theseexpressions are also important when new capacities such as ground-to-groundmissile systems are discussed. Furthermore there have to exist political willand military conditions before such systems can be realized. This work examinesif there are political willingness and military circumstances to realizeSLAM-systems aboard tomorrow’s Swedish man-of-war. To get it comprehensiblethe work also includes a brief description of similar, existing, andimagined future missile systems. Further on the work sheds light on how thesystems could be attached to the Swedish operational philosophy of militarycommand and finally how they connect to the Swedish military operationalimperatives. The underlying theories of the composition are the theories aboutmanoeuvre warfare and network centric warfare.
Avdelning: ALB - Slutet Mag 3 C-upps.Hylla: Upps. ChP 01-03

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Valdes, Serra Juan Carlos. "Caracterização mecanico-metalurgica de compositos A1-Nbc, produzidos por metalurgia do po." [s.n.], 1998. http://repositorio.unicamp.br/jspui/handle/REPOSIP/263655.

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Анотація:

Orientadores: Maria Helena Robert, Jesualdo Luiz Rossi
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica
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Resumo: o presente trabalho apresenta a caracterização mecânico-metalúrgica de compósitos constituídos de Al reforçado com 5, 10 e 15%vol de partículas NbC, fabricados por metalurgia do pó, e no estado extrudado. A caracterização metalúrgica envolveu a análise do efeito do processamento na estabilidade das partículas de NbC, a análise de sua distribuição macroscópica na estrutura dos compósitos e a análise de interfaces reforço/matriz por MEV. Os resultados obtidos mostraram que as partículas de NbC podem soffer ffatura durante processamento, mas não têm alteradas suas dimensões; reações de interface não foram observadas e uma homogênea distribuição macroscópica das partículas de reforço foram obtidas nos compósitos, embora microscópicamente tenha sido observada tendência à aglomeração de partículas com o aumento do teor de reforço utilizado. Os compósitos foram também caracterizados quanto à expansão térmica e densidade aparente. Os resultados obtidos indicam redução do coeficiente de dilatação linear do Al da ordem de 17. a 26.% com a adição de teores de NbC de 5 a 15%vol, respectivamente; e aumento na densidade aparente da ordem de 15 a 20% para as mesmas adições...Observação: O resumo, na íntegra, poderá ser visualizado no texto completo da tese digital
Abstract: The work deals with the metalIurgicaland mechanical characterization of composites Al-NbC containing 5, 10 and 15% vol of NbC particles, in the extruded condition. Composites were produced from Al 1100 and NbC powders (average powder diameter 25 and 2,3 um, respectively), and subsequently extruded to bars. MetalIurgical characterization involved the analysis of the stability of reinforcement particles and their macroscopic distribution within the matrix as welI as the analysis of particles/matrix interface by MEY. Results showed that fracture can occurs in the particles of NbC at some extent; no interface reactions and changes in particles dimensions were observed. Homogeneous macroscopic distribution of NbC particles was obtained in all cases; therefore, microscopically it could be observed agglomeration of NbC as its vol fraction increases. It was also characterized thermal expansion and apparent density. Results showed decrease in the coefficient of linear thermal expansion in the order of 17 to 26% related to Al alone, as NbC content increases from 5 to 15% vol, respectively; and an increase of 15 to 20% in apparent density, for the same conditions...Note: The complete abstract is available with the full electronic digital thesis or dissertations
Mestrado
Materiais e Processos de Fabricação
Mestre em Engenharia Mecânica

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Tonello, Karolina Pereira dos Santos. "Compósitos à base de Al2O3, com adições de NbC e de MgO." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/85/85134/tde-15102009-153306/.

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Avanços tecnológicos geram a necessidade de materiais com propriedades cada vez melhores, de acordo com a sua aplicação final. Compósitos de alumina com adição de partículas de carbeto são uma opção promissora de aplicação estrutural. Neste trabalho foi estudada a influência da diferença de distribuição e tamanho de partículas de duas aluminas comerciais, a adição de 1,5 e 6% em volume de carbeto de nióbio e a adição de 500 ppm de óxido de magnésio, nas propriedades microestruturais e mecânicas de compósitos à base de alumina. Foram preparados corpos de prova por prensagem uniaxial e isostática, sinterizados em forno de resistência de grafite a temperaturas de 1600, 1650, 1700 e 1750°C, por trinta minutos, em atmosfera com pressão positiva de argônio. As amostras obtidas foram avaliadas quanto à densidade, microestrutura e propriedades mecânicas. Também foram realizados ensaios de difusão para verificar a reatividade química entre pares formados por amostras de alumina e ferro fundido cinzento. As características físicas e químicas das aluminas comerciais utilizadas acarretaram diferenças nos materiais finais; os compósitos produzidos com alumina A16 apresentaram densidade maior do que os produzidos com alumina A1000, nas mesmas condições; assim como os valores de dureza também foram maiores. A adição de 6vol% de carbeto de nióbio à matriz de alumina retarda o início da sinterização, enquanto que a adição de 1,5vol% não provoca mudanças sensíveis na cinética de densificação em relação aos materiais sem adição. Os valores de densidade e dureza dos compósitos contendo 1,5vol% de NbC foram superiores nas menores temperaturas de sinterização utilizadas. Os melhores resultados de densificação (>96% Dt) e dureza (>15GPa) foram obtidos para compósitos produzidos com alumina A16 e adição de 1,5% de NbC.
The worldwide technological advances generate the needs of improved materials with better properties, according to its final purpose. Alumina composites with the addition of carbide particles have become an interesting option for structural applications. This work studies the influence of two commercial aluminas with different particle size and the adding of 1.5 and 6% in volume of niobium carbide and MgO 500 ppm in microstructural and mechanical properties of the composite. Samples were prepared by uniaxial and isostatic pressing and sintering was carried out in a graphite resistance furnace at 1600, 1650, 1700 and 1750°C for thirty minutes in Ar atmosphere. The obtained samples were evaluated sintering behavior, density, microstructure and mechanical properties, diffusion tests were realized to verify chemical reactivity between pairs formed by alumina and gray cast iron samples. The differences between aluminas caused some changes on the composites final properties. The composites produced with A16 alumina presented density about 2% higher than those produced with A1000 alumina. Similarly, the hardness also showed higher values. The carbide niobium added to the matrix of alumina delayed the sintering start, with an increase of about 30% in shrinkage initial states, when 6% of NbC was added. Composite with addition of 1,5% of NbC have higher density and hardness, even at lower sintering temperatures. The adding of niobium carbide to the alumina matrix and higher sintering temperatures provided higher density, hardness and fracture toughness to the composite. The best densification and hardness results of were obtained for composites produced with alumina A16 and when 1.5% of NbC was added.

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FERREIRA, VANDERLEI. "Processamento, caracterizacao mecanica e tribologica do composito Alsub(2)Osub(3)-Nbc." reponame:Repositório Institucional do IPEN, 2001. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10894.

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Dissertacao (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

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Annereau, Jean-Philippe. "Une approche structurale et fonctionnelle du domaine NBF1 de la protéine CFTR : implications pour la mucovisidose." Palaiseau, Ecole polytechnique, 1998. http://www.theses.fr/1998EPXX0015.

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Анотація:

Dans 70% des cas, la mucoviscidose est due à une délétion de la phenylalanine 508 dans la protéine cftr (cystic fibrosis transmembrane conductance regulator), canal membranaire de la famille des transporteurs abc (atp binding cassette). Cette délétion, située dans un domaine cytoplasmique : nbf1 (nucleotide binding fold 1), altère l'intégrité structurale de la protéine cftr. De nombreuses études in vitro ont permis de prédire que le rôle de cftr est de réguler les mouvements d'ions chlorures à travers la membrane apicale des cellules épithéliales. Cependant, la mucoviscidose ne peut s'expliquer uniquement par une altération des mouvements ioniques. Aussi, pour rechercher de nouvelles fonctions pour cftr, une approche de modélisation moléculaire du domaine nbf1 de cftr a été réalisée par homologie avec les structures cristallographiques des domaines nbf et nbf de l'atpase fof1. Le modèle reconstruit montre d'une part que la mutation df508 se situe dans une région cruciale pour la stabilité du domaine nbf1, mais indique aussi une nouvelle topologie pour la proteine cftr, très proche des protéines de type abc. Dans le but de réaliser un échantillon pour des etudes structurales, les domaines recombinants de nbf1 de cftr, correspondant au nouveau modèle, ont été exprimés chez e. Coli puis purifiés. Ces éléments ont permis une relecture de la bibliographie existante sur cftr. Ainsi, des points communs étroits entre cftr et d'autres protéines abc ont pu être mis en évidence au niveau fonctionnel, mais aussi au niveau de la localisation et la régulation de leur expression (notamment avec mrp : multidrug resistance protein). Ces similitudes fonctionnelles ouvrent de nouvelles perspectives thérapeutiques. Une approche innovante serait en effet de complémenter l'absence de cftr par d'autres protéines abc dont les fonctions se recouvrent et dont l'expression est activable par des drogues connues.

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Spirandeli, Bruno Roberto. "Influência da adição de NbC e Al2O3+TiO2 nos desempenhos de revestimentos a base de Ni-Al produzidos por aspersão térmica." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/18/18158/tde-12032015-151858/.

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Aspersão térmica é um processo de produção de revestimentos metálicos, poliméricos, cerâmicos ou compósitos sobre superfícies previamente preparadas que objetiva na maioria das vezes a prevenção contra o desgaste e/ou corrosão e também a recuperação dimensional de superfícies desgastadas. Ligas de Ni-Al são extensivamente empregadas na aspersão térmica para reconstrução dimensional e como camada de ligação como materiais que não se ligam adequadamente à superfície a ser revestida. A baixa dureza e resistência ao desgaste (principalmente em aplicações de reconstrução dimensional) desta liga poderiam ser contornadas pela adição de partículas ou compostos de altas durezas na matéria prima em pó antes da aspersão. Neste trabalho avaliou-se a influência da adição de NbC e do composto cerâmico Al2O3+TiO2 no desempenho ao desgaste de revestimentos de Ni-Al, bem como verificou-se as alterações microestruturais, químicas, e mecânicas decorrentes. Para tanto se adicionou 25%p de NbC ou 25%p do composto Al2O3+TiO2 à liga base de Ni-Al, formando-se dois materiais compósitos: Ni-Al + NbC e Ni-Al + (Al2O3+TiO2). Utilizou-se microscópio eletrônico de varredura com EDS para caracterizar as matérias primas e os revestimentos produzidos, assim como determinar o mecanismo de desgaste nos ensaios de micro-abrasão tipo \"esfera-livre\" e \"esfera-fixa\". Mediram-se as durezas superficiais e as microdurezas das fases por meio dos ensaios Rockwell Superficial e microdureza Vickers. Avaliou-se a resistência ao desgaste por meio de ensaios de micro-abrasão nas modalidades \"esfera-livre\" e \"esfera-fixa\". As adições dos materiais citados na liga a base de níquel alteraram características microestruturais importantes, como aumento do percentual de óxidos, bem como a composição química e distribuição dos elementos nas camadas formadas; ocorreram também aumentos significativos das durezas e nas resistências ao desgaste dos revestimentos.
Thermo Spray is a metallic, polymeric, ceramic and composite coating process applied over a previously prepared surface usually seeking to improve wear and/or corrosion resistance. It is also used to repair worn surfaces restoring the original dimensions. Ni-Al alloys are used as a primer coating to promote the adhesion between surface and incompatible coatings and also extensively in the reconstruction of worn surfaces. The low hardness and wear resistance (when used in reconstruction applications) of this alloy could be improved by the addition of hard particles/composites to the powdered raw material prior to the spray operation. In this work the influence of NbC and Al2O3+TiO2 additions to Ni-Al alloys were evaluated concerning wear performance and the resulting changes in microstructure, chemical and mechanical behavior. The experimental procedure included the preparation of samples of the Ni-Al base alloy with additions of 25wt% of NbC or 25wt% of Al2O3+TiO2, what resulted in two different sprayed composite materials: Ni-Al + NbC e Ni-Al + (Al2O3+TiO2). SEM with EDS microprobe was used to characterize the raw materials, the sprayed coating samples and the type of wear mechanism occurring in the wear tests of the type \"free sphere\" and \"fixed sphere\" micro abrasion that were used to evaluate the wear resistance of the samples. Surface hardness and micro hardness of the different phases in the coatings were evaluated using Rockwell and Vickers micro hardness testing machines respectively. The addition of the hard phases promoted important changes in the Ni-Al base alloy, decreasing the porosity level and increasing the percentage of oxides. Hardness were significantly increased as well as the wear resistance of the coatings.

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Soares, Maria da Conceição Barbosa Vieira, and Instituto de Engenharia Nuclear. "Estudo inicial da influência de nióbio e carbono na recristalização e propriedades mecânicas do níquel." Instituto de Engenharia Nuclear, 1986. http://carpedien.ien.gov.br:8080/handle/ien/2017.

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O trabalho procura estudar os efeitos da adição de nióbio e carbono no processo de recristalização do níquel quando laminado a quente. Para tanto foram elaborados por fusão a vácuo, lingotes de uma liga Ni-0,5 Nb - 0,05 C em peso e de níquel eletrolítico, e suas características mecânicas e metalográficas "determinadas após duas condições distintas de laminação a quente: cinco e seis passes sucessivos de laminação (69% e 75% de redução, respectivamente), partindo de uma temperatura de 1200°C. Foi constatado que a adição de nióbio e carbono promove uma redução no tamanho de grão recristalizado e que, sob determinadas condições de deformação e temperatura mais baixas, a recristalização da austenita e inteiramente restringida. Algumas evidencias iniciais são apresentadas, indicando uma posssível atuação de partículas precipitadas no retardo da recristalização, de maneira análoga ã atuação de carbonetos e carbonitretos de nióbio nos aços microligados.
The aim of the work is to study the effects of Niobium and Carbon additions on Nickel recrystallization during hot rolling. The study was performed on electrolitic Nickel and a Ni-0.5 Nb-0.05 C % wt alloy prepared in a vacuum furnace. Mechanical and metallographic properties of both were determined after two treatments: five and six pass of hot rolling with 69% and 75% reduction respectively and temperatures ranging from 1200°C to 860°C. It was identified that Niobium and Carbon additions cause a decrease in the recrystallized grain size and at certain conditions of deformation and temperature may even inhibit Nickel recrystallization. The formation of NbC precipitates is reported as apossible cause for the inhibition of Nickel recrystallizationas it is in HSLA steels.

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Stragnefeldt, Stefan. "Ledarskap och det Nätverksbaserade försvaret - hur skapas tillit inom de behovssammansatta förbanden i NBF?" Thesis, Försvarshögskolan, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:fhs:diva-1727.

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Ett av målen inom det nätverksbaserade försvaret, NBF, är skapandet avbehovssammansatta förband, det vill säga möjligheten att snabbt kunna kombinera olikaresurser inför en specifik uppgift. Tillit inom dessa förband framstår här som en mycketviktig parameter för att de ska kunna agera gemensamt mot uppställda mål.Denna uppsats genomförs som en kvalitativ undersökning och dess syfte är att, genomintervjuer med officerare ur Armén och Helikopterflottiljen, söka svar på hur man skakunna skapa tillit inom dessa behovssammansatta förband. Empirin från genomfördaintervjuer har prövats mot de ledarskapsteorier som idag används inom den svenskaFörsvarsmakten, samt mot en utvald del av den svenska teorimängd som idag finns atttillgå om nätverksbaserat försvar.Resultatet visar hur viktigt det är att Försvarsmakten snarast börjar öva i NBF-miljöer, trotsatt materiel och metoder inte är färdigdefinierade. Dessutom påvisas att det idag inte finnsen tillräckligt klar definition inom den svenska Försvarsmakten av vad begreppetbehovssammansatta förband innebär och att denna snarast bör skapas. Därutöver visas atttillit inom behovssammansatta förband både består av förtroende för utsedda chefer, samttillit mellan ingående förband. För att skapa denna tillit är det personliga mötet ochkontinuerliga övningar i olika förbandssammansättningar av fortsatt central betydelse.
Military units, designed and temporarily put together, for specific missions areone of the aims in the Swedish Network-based Defence. Trust within these unitsseems to be an important parameter to make them act jointly against a target.The main purpose of this qualitative examination is, trough interviews withofficers in the Swedish Army and Helicopter Wing, search for answers about howto create trust in these units. The interview answers has been examined against theleadership theories which are used today in the Swedish Defence Force andagainst some of the theories which today can be found in Sweden about theNetwork-based Defence.The result indicates that it is very important for the Swedish Defence Force toimmediately start exercise in Network-based environments. It also indicates thatthe Swedish Defence Force today doesn’t have a definite definition about whatmilitary units designed for specific missions in the Network-based Defence areand this must be created ASAP. It also indicates that trust in these units consistsof trust for the military commanding officers and trust within these units.Exercises and human contacts are two very important factors to create this trust,also in the Network-based Defence.
Avdelning: ALB - Slutet Mag 3 C-upps.Hylla: Upps. ChP 02-04

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Adegbola, Oluseyi. "U.S. television reporting of the Arab Spring| A study of ABC, CBS and NBC." Thesis, University of Nebraska at Omaha, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10139262.

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Reporting of international conflict has implications for understanding, political action, and policy formation. This means media coverage can influence the outcomes of conflict. This study investigated reporting of the Arab Spring conflicts by U.S. television networks (ABC, CBS, and NBC). The study examined the time frame between the onset of the uprising and February 29, 2012 when dictators were unseated in Tunisia, Egypt, Libya, and Yemen. Agenda-setting and media framing theory were used to analyze transcripts (N = 316) for dominant issues, sources used, frames and, social media. Results of the study corroborate existing research regarding conflict reporting. Coverage was mostly episodic and dominated by violence, however, attention was paid to the role of social media in overthrowing regimes, violent acts of regime brutality, and democracy. Core causes of the uprising received only marginal coverage. Ordinary domestic citizens were used most frequently as sources. Other findings applicable to U.S. media coverage are presented.

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Salem, Raphael Euclides Prestes. "Desenvolvimento de ZrO2/Al2O3 e ZrO2/Al2O3-NbC usando sinterização convencional e não convencional." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/74/74133/tde-26022018-094441/.

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Os compósitos cerâmicos de alto desempenho têm sido objeto de frequentes estudos nas últimas décadas, visando à melhora das propriedades mecânicas e ao aumento da sua gama de aplicações em produtos tecnológicos. Este trabalho consistiu em estudar a preparação, a sinterização convencional e não convencional e as propriedades mecânicas e tribológicas resultantes de dois sistemas compósitos: t-ZrO2/Al2O3 e t-ZrO2/Al2O3-NbC. No sistema t-ZrO2/Al2O3 foram estudadas as composições de 0, 5 e 15% em volume de Al2O3 usando pós comerciais. No sistema t-ZrO2/Al2O3-NbC, foi usado um pó nanocristalino de Al2O3-NbC, obtido por moagem reativa de alta energia e adicionado na proporção de 5% em volume à matriz de t-ZrO2. Os pós foram prensados uniaxial e isostaticamente e sinterizados em forno convencional e pelas técnicas de flash sintering (FS) (t-ZrO2/Al2O3) e spark plasma sintering (SPS) (t-ZrO2/Al2O3-NbC). Os compósitos t-ZrO2/Al2O3 sinterizados convencionalmente e t-ZrO2/Al2O3-NbC sinterizados convencionalmente e por SPS foram caracterizados por medidas de densidade aparente, dilatometria, microscopia eletrônica de varredura (MEV), e medidas de propriedades mecânicas: dureza, módulo de Young e tenacidade à fratura. Os compósitos t-ZrO2/Al2O3 sinterizados por FS foram caracterizados por medidas de densidade aparente, dilatometria in situ e MEV. Os nanocompósitos de t-ZrO2/Al2O3-NbC foram também caracterizados quanto à resistência ao desgaste pelo método esfera-no-disco, utilizando esferas de Al2O3 e WC-6%Co como contramateriais. Os resultados mostraram que a moagem reativa de alta energia foi completa e efetiva na obtenção de pós nanométricos de Al2O3-NbC, com tamanhos de cristalito de 9,1 nm para Al2O3 e 9,7 nm para o NbC. A desaglomeração posterior à moagem de alta energia foi eficaz na redução do tamanho de aglomerados. Os compósitos t-ZrO2/Al2O3 e t-ZrO2/Al2O3-NbC sinterizados convencionalmente e ZrO2/Al2O3-NbC sinterizados por SPS mostraram alta densificação (>97% DT e boas propriedades mecânicas. Os nanocompósitos de t-ZrO2/Al2O3 sinterizados por FS apresentaram uma densificação ultrarrápida (< 1 min) com retração linear superior às amostras sinterizadas em forno convencional, ocorrente a temperaturas inferiores a 1000°C, com densidades relativas superiores a 90% DT em algumas composições. Os nanocompósitos de t-ZrO2/Al2O3-NbC apresentaram propriedades competitivas entre os compósitos sinterizados convencionalmente e por SPS, com dureza e tenacidade à fratura superiores às da t-ZrO2 monolítica. A resistência ao desgaste desses nanocompósitos sinterizados convencionalmente, no entanto, foi notadamente superior à dos sinterizados por SPS. A oxidação do NbC nos compósitos sinterizados convencionalmente influiu negativamente nas propriedades, levando à sugestão de uma \"janela\" de temperaturas em que a sinterização do nanocompósito de t-ZrO2/Al2O3-NbC seja interessante sem a degradação das propriedades mecânicas. Os resultados permitiram concluir que os materiais estudados apresentam potencial para aplicações industriais que requerem cerâmicas de alto desempenho mecânico e de resistência ao desgaste.
High performance ceramic composites have been the subject of frequent studies in recent decades, aiming at improving mechanical properties and increasing their range of applications in technological products. This work consisted in studying the preparation, the conventional and non-conventional sintering and the mechanical properties resulting from two t-ZrO2 matrix composites: the t-ZrO2/Al2O3 system and the t-ZrO2/Al2O3-NbC system. In the t-ZrO2/Al2O3 system, the compositions of 0, 5 and 15% by volume of Al2O3 using commercial powders were studied, while in the t-ZrO2/Al2O3-NbC system, an Al2O3-NbC nanocrystalline powder obtained by high energy reactive milling, deagglomerated, leached in HCl and added in the proportion of 5% by volume to the t-ZrO2 matrix. The obtained powders were uniaxially and isostatically pressed and sintered in conventional furnace and using flash sintering (t-ZrO2/Al2O3) and spark plasma sintering (SPS) (t-ZrO2/Al2O3-NbC). Conventionally sintered t-ZrO2/Al2O3 and conventionally sintered t-ZrO2/Al2O3-NbC composites were characterized by measurements of apparent density, dilatometry, SEM, and mechanical properties: hardness, Young\'s modulus and fracture toughness. The t-ZrO2/Al2O3 composites sintered by FS were characterized by measurements of apparent density, in situ dilatometry and SEM. t-ZrO2/Al2O3-NbC nanocomposites were also characterized for wear strength by the ball-in-disc method, using Al2O3 and WC-6%Co beads as countermaterials. The results showed that the high energy reactive milling was complete and effective in obtaining nanometric powders of Al2O3-NbC, with crystallite sizes equal to 9.1 and 9.7 nm, for Al2O3 and NbC, respectively. The deagglomeration after high energy reactive milling was effective in reducing the size of agglomerates. Conventionally sintered t-ZrO2/Al2O3 and t-ZrO2/Al2O3-NbC composites and SPS-sintered t-ZrO2/Al2O3-NbC showed high densification (> 97% TD), good dispersion of the inclusions in the matrix and good mechanical properties. The t-ZrO2/Al2O3 nanocomposites sintered by FS presented an ultrafast densification (<1 min) with linear shrinkage superior to the sintered samples in conventional furnace, occurring at temperatures lower than 1000°C, with relative densities higher than 90% TD in some compositions. The t-ZrO2/Al2O3-NbC nanocomposites presented competitive properties between conventionally sintered and SPS-sintered composites with higher hardness and fracture toughness than monolithic t-ZrO2. The wear resistance of these conventionally sintered nanocomposites, however, was markedly higher than those of SPS-sintered ones. The oxidation of NbC in the composites sintered conventionally influenced negatively the properties, leading to the suggestion of a \"window\" of temperatures in which the sintering of the t-ZrO2/Al2O3-NbC nanocomposite is interesting without the degradation of the mechanical properties. The results allowed concluding that the studied materials present potential for industrial applications that require high mechanical performance and wear resistance ceramics.

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32

Bémont, Emilie. "La germination du carbure de niobium NbC dans la ferrite vue par tomographie atomique." Rouen, 2003. http://www.theses.fr/2003ROUES040.

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La germination des carbures de niobium NbC dans une matrice ferritique est un phénomène généralement décrit par la théorie de la germination et croissance. Cependant, l'écart paramétrique considérable entre les structures cristallographiques de la phase NbC et de la ferrite implique que la germination homogène de la phase d'équilibre est impossible. L'objectif de ce travail est de déterminer le processus de formation des précipités NbC aux tout premiers stades. Etant donnée la très petite taille des objets à caractériser, cette étude nécessite l'emploi d'une technique d'analyse à l'échelle atomique : la sonde atomique tomographique (TAP). De plus, la précipitation de la phase NbC dans la ferrite impose des concentrations en solutés extrêmement faibles, de l'ordre de la centaine de ppm atomiques. L'étude requiert donc une technique à haute résolution en masse. Parallèlement, une activité d'instrumentation a donc été menée, dont le but était d'optimiser le fonctionnement d'une sonde atomique tomographique à haute résolution en masse (ECoTAP). Par l'incorporation d'un réflectron, les performances de la sonde atomique tomographique classique ont nettement augmenté. La résolution en masse, et par suite la limite de détection de l'instrument, ont été améliorées par un facteur 8. L'étude des premiers stades de la précipitation des carbures de niobium dans la ferrite a montré que les germes précurseurs sont des nuages diffus d'atomes de solutés, qui ne perturbent pas la structure cristallographique de la matrice ferritique. Ces germes évoluent ensuite vers une phase métastable de type (Fe;C)Nb qui s'appauvrit progressivement en fer jusqu'à atteindre la phase d'équilibre NbC. Le rôle de l'azote dans cette séquence de précipitation a pu être déterminé par une étude similaire portant sur les carbonitrures de niobium Nb(C;N). Les résultats obtenus montrent également une précipitation de la phase d'équilibre par l'intermédiaire d'une phase métastable riche en fer. Cependant, la phase transitoire n'est plus de type (Fe;Nb)C mais (Fe;Nb)N. Ces germes précurseurs s'enrichissent en carbone et parallèlement, s'appauvrissent en fer pour parvenir à la phase d'équilibre Nb(C;N)
The nucleation and growth theory is usually used to describe the precipitation of NbC niobium carbides in a ferritic matrix. However, the important mismatch between the NbC phase and ferrite crystallographic structures induces that homogeneous nucleation of the equilibrium phase is not possible. This work aims at describing the formation process of NbC precipitates at the early stages. On the one hand, the size of the precipitates to characterise is very small. Using a technique of investigation at the atomic scale is necessary : the tomographic atom probe (TAP). On the other hand, the precipitation of the NbC phase in ferrite imposes very low concentrations in solutes, around a hundred of atomic ppm. The study requires a very sensitive technique. Consequently, an instrumentation activity was carried out, aiming at determining the steady state of an energy compensated optical tomographic atom probe (ECoTAP). The incorporation of a reflectron to the instrument lead to the improvement of the TAP performances. The mass resolution and the detection limit of the technique are enhanced by a factor 8. The study of the early stages of precipitation of the NbC phase in ferrite shows that the first nuclei are diffuse clouds of solute atoms. These ones respect the crystallographic structure of the ferritic matrix. The nuclei then evolve towards a (Fe;Nb)C metastable phase which iron concentration progressively decreases so as to obtain the NbC equilibrium phase. The role of nitrogen in this precipitation sequence was determined with a similar study focused on Nb(C;N) niobium carbonitrides. The results thus obtained also show the existence of an intermediate metastable phase enriched in iron. However, this transient phase is not (Fe;Nb)C but (Fe;Nb)N. These nuclei come richer and richer in carbon with a decrease of the iron concentration. The Nb(C;N) equilibrium phase then appears

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33

Callie, Mary Elizabeth. "In NBC we trust: The public interest, hegemony, and the "Today"show, 1952-1958." Diss., The University of Arizona, 2002. http://hdl.handle.net/10150/280158.

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This dissertation considers processes of hegemony, or the construction of consent, in network television marketing practices in the 1950s. Specifically, a case study of the Today show, which premiered in 1952, examines how RCA, and subsidiary network NBC, generated consent for continuing domination of the national television airwaves. In the context of post-World War II concern about the place of the multi-national corporations and the media in American democracy, RCA/NBC constructed its company, programming, and the image of its audience within a nexus of anti-trust, good trust (or legal monopolies/public utilities), and free speech/free press regulations. To understand this regulatory context, the study begins by identifying the deep structural contradictions of liberal democratic capitalism and the political economic conditions which demand that power, privilege, and control be legitimated. These conditions shape rhetorics of common interest through which groups and individuals---empowered by the state with delegated authority---seek to establish and maintain consent. This control is constructed as an exception to the rules of free trade and free speech/press. In the end, the study suggests that processes of hegemony construct market control---and consumer free choice---as natural, preordained, and in the best interests of the public as a whole, while downplaying, denying, or discrediting any other real alternatives or possibilities. The particular findings of this deep historical and case study can inform present day broadcast reform efforts and offer core approaches for re-framing hegemonic corporate rationales.

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34

Alves, Artur Jorge de Matos. "Criador e Criatura: o papel das tecnologias da informação e comunicação no novo contexto das tecnologias emergentes." Master's thesis, Universidade Nova de Lisboa, Faculdade de Ciências Sociais e Humanas, 2009. http://hdl.handle.net/10362/5879.

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Dissertação apresentada para cumprimento dos requisitos necessários à obtenção do grau de Doutor em Ciências da Comunicação
Procurar-se-á responder à questão seguinte: qual o papel das novas tecnologias da informação e comunicação no contexto criado pelas tecnologias emergentes? Este questionamento vai de encontro ao objectivo de compreender a importância das TIC na experiência tecnológica contemporânea, enquadrando-a numa abordagem dos estudos sobre ciência, tecnologia e sociedade que possa integrar coerentemente os novos conhecimentos sobre a percepção, representação e cognição. Surge, aqui, uma questão secundária relevante, relativa à confrontação destas novas perspectivas de criação de sistemas híbridos com as tradições e conceptualizações que dizem respeito às sucessivas tecnologias e que abundam na divulgação e futurologia científicas: como se pode conceber esta evolução do ponto de vista de uma filosofia da tecnologia? E como se expressa esta através das tecno-utopias? Existe uma continuidade ou um corte fundamental entre as formas tecnológicas e as tecno-utopias do presente e as do passado? Este questionamento está relacionado com a envolvente tecnológica já instalada, mas sobretudo com as suas reconfigurações, que se anunciam como hipótese de futuro ou imagem ficcional: poderão as novas tecnologias reconstruir toda a sociedade e sistema político, sob os signos da racionalidade geral e do pós-humanismo? Poderá o ser humano ser regido por sistemas maquínicos ultra-eficientes, como aponta alguma ficção científica? Partindo do princípio que a crise, ou pelo menos a invocação de uma crise das instituições políticas e sociais, é um dado adquirido, de que promessas ou riscos são as novas tecnologias emergentes portadoras? Em especial, qual o papel das TIC neste processo? Propõe-se uma compreensão das tecnologias da comunicação e informação no seu papel de espelho e motor das aspirações humanas para a Humanidade e a sociedade. Uma vez que esta problemática se situa no cruzamento de diversas questões, será necessário um estudo prévio da sua genealogia múltipla, do conhecimento científico e técnico das TIC e das NBIC, da própria ideia de interacção e comunicação e, paralelamente, as perspectivas da filosofia da tecnologia sobre estas mutações, analisando as possíveis repercussões e novos questionamentos na área político-social que a emergência destes fenómenos pode trazer. Defende-se, no contexto da democracia, um agenciamento convivial das tecnologias, e das TIC em particular, cujos efeitos permitiriam um alargamento do espaço de discussão sobre estas. Esta praxis equivale à construção/instituição de uma relação mais próxima da maioridade com as TIC (e outras tecnologias, potencialmente), mas também a uma nova compreensão do papel público destas e das tecnologias emergentes. A este respeito, ganha especial importância a reflexão ético-filosófica sobre os efeitos da colonização do ser humano pelas NBIC e da sujeição – ou enquadramento – do mundo natural e social às determinações da tecnicidade.

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Uehara, José Luis Hideki Sakihama. "Estudo de materiais com gradiente funcional (MGF) a base de alumina (Al2O3) e carbeto de nióbio (NbC) obtidos por diferentes técnicas de sinterização." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/18/18158/tde-29092015-144827/.

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No presente trabalho, peças com gradiente funcional de Al2O3 com reforço de NbC foram planejadas com o intuito de obter um MGF (material com gradiente funcional) com uma alta dureza e boa tenacidade à fratura a partir de diferentes técnicas de sinterização. Os MGFs apresentam-se como uma excelente alternativa quando é necessária a união de materiais com propriedades térmicas ou mecânicas muito diferentes, já que possuem uma transição suave de propriedades ao longo do corpo, como consequência de uma mudança gradual do teor das fases. No planejamento dos MGFs foram utilizadas análises dilatométricas para compatibilizar o comportamento durante a sinterização de cada camada e assim minimizar as tensões que ocorrem durante a retração, responsáveis por trincas e delaminações. Nos ensaios de dilatometria observou-se que a diferença máxima de retração entre os compósitos de teor de NbC variando de 5 a 30 %p é de 4,85%, assim, foram projetados MGFs com um passo de 5% de NbC, reduzindo esta diferença para 2,73%. Compósitos monolíticos de Al2O3 com diferentes teores de NbC foram sinterizadas a 1500ºC num forno convencional sob atmosfera de grafite. As densidades das peças sinterizadas foram inferiores a 90% da densidade teórica (DT), o que comprometeu a dureza dos compósitos (10 a 14 GPa), inferiores que as durezas dos materiais originais. Uma das maiores dificuldades no processamento destes compósitos foi sua densificação, prejudicada devido à presença de partículas de alta refratariedade na matriz de alumina, pelo que foi realizado um estudo do efeito da nióbia (Nb2O5) como auxiliar de sinterização nos compósitos Al2O3-NbC. Utilizando 0,5 %mol deste aditivo foi possível melhorar as densidades dos compósitos que, segundo os resultados da microscopia eletrônica de varredura (MEV), devido a uma densificação em presença de fase líquida. No entanto, a melhora na densidade é efetiva para temperaturas inferiores a 1450°C devido provavelmente à sobrequeima. Devido às dificuldades para obter peças densas a partir desses compósitos, foi utilizado o processo de Spark Plasma Sintering (SPS), o qual foi bem sucedido para obter peças com gradiente funcional com boa densidade (> 98 %TD) e livres de trincas. O gradiente projetado foi mantido com sucesso após a sinterização e, graças à alta densidade das peças, foi possível atingir altas durezas (até 24,3 GPa) e tenacidade à fratura ~5 MPa.m1/2, fazendo com que estes materiais apresentem potencial de aplicação como ferramentas de corte.
In the present work, Al2O3/ NbC graded composites were designed in order to obtain a FGM with a high hardness and good fracture toughness from different sintering techniques. Functionally graded materials (FGM) present enormous potential on matching materials that have different mechanical and thermal properties via a gradual transition throughout the body, as a consequence of a gradual transition of the phase content. For designing of FGMs, a dilatometric analysis was used for matching the sintering behavior of each layer in order to minimize the thermal strains occurring during shrinkage and that are responsible for cracking and delamination. It was observed that the maximum difference in shrinkage between these composites is 4.85%, which could be reduced to 2.73% if a FGM with step of 5% NbC is produced. Monolithic composites of Al2O3 with different amounts of NbC were sintered at 1500°C in a conventional oven under an atmosphere of graphite, the density of the sintered pieces were less than 90 %TD, compromising the hardness of the composites (10 to 14 GPa) that were lower than the hardness of the original materials. Due to the fact that one of the greatest difficulties in processing these composites is a densification, which is impaired due to the presence of high refractory particles in the alumina matrix, a study of the effect of the niobia (Nb2O5) as a sintering aid in the composite Al2O3-NbC was conducted, with addition of 0.5 mol% was possible to improve the density of the composites, due to the liquid state sintering according to the SEM results. However, this effect is only effective until a temperature of 1450°C probably due to the overfiring. In order to obtain dense bodies from these composites, Spark plasma sintering (SPS) was used. This process was successful for producing functional graded bodies with good density (> 98% TD) and crack free. The designed gradient was successfully maintained after sintering and due to the high density of FGMs, it was possible to attain high hardness (up to 24.3 GPa) and a fracture toughness of ~ 5 MPa.m1/2, showing that these materials have a good potential application as cutting tools.

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36

Schiffman, James R. "Mass Media and Representation: a Critical Comparison of the CCTV and NBC Presentations of the Opening Ceremony of the 2008 Beijing Olympic Summer Games." Digital Archive @ GSU, 2012. http://digitalarchive.gsu.edu/communication_diss/31.

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A critical comparison of the CCTV and NBC broadcasts of the Opening Ceremony of the 2008 Beijing Olympics demonstrates how two sets of narratives that on the surface glorify China and the long Chinese cultural and historic tradition offer very different ideological projections about China's rise as a power and engagement with the wider capitalist world. For CCTV, China has finally righted a longstanding historical injustice and established itself as a co-equal nation among nations. For NBC, ambivalence about China is the watchword, and further reforms that by implication will help clear China of its non-democratic, totalitarian, and economically mercantilist sheen are needed if the country is to be fully embraced. The ideological construction is more hidden in the NBC broadcast, but both depend on massive erasures of history and blurring of contemporary issues, causing both sets of narratives to fail tests of narrative coherence. Discursive struggles over the authorship of the Opening Ceremony underlie both media texts and expose their ideological positioning.

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TONELLO, KAROLINA P. dos S. "Compositos a base de Alsub(2)Osub(3) com adicoes de NbC e de MgO." reponame:Repositório Institucional do IPEN, 2009. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11780.

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Made available in DSpace on 2014-10-09T12:55:44Z (GMT). No. of bitstreams: 0
Made available in DSpace on 2014-10-09T14:05:13Z (GMT). No. of bitstreams: 0
Dissertação (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

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38

Єрьоменко, Ян Миколайович. "Моделювання динаміки ринку високотехнологічної продукції України". Магістерська робота, Київський національний університет технологій та дизайну, 2021. https://er.knutd.edu.ua/handle/123456789/19471.

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Дипломну магістерську роботу присвячено дослідженню теоретичних аспектів моделювання динаміки ринку високотехнологічної продукції України та проведенню компаративного аналізу переваг торгівлі високотехнологічною продукцією. Практичне значення одержаних результатів полягає у проведенні комплексного аналізу розвитку ринку високотехнологічної продукції України та ЄС, моделюванні розвитку торгівлі високотехнологічною продукцією на основі кореляційно-регресійного аналізу та визначенні шляхів підвищення ефективності торгівлі на ринку високотехнологічної продукції. Наукова новизна полягає у досконалому вивченні розвитку ринку високотехнологічної продукції України, аналізі факторів впливу та прогнозуванні перспектив його розвитку.
The master's thesis is devoted to the study of theoretical aspects of modeling the dynamics of the market of high-tech products of Ukraine and conducting a comparative analysis of the benefits of trade in high-tech products. The practical significance of the obtained results is to conduct a comprehensive analysis of the development of the market of high-tech products of Ukraine and the EU, modeling the development of trade in high-tech products based on correlation and regression analysis and identify ways to improve trade in high-tech products. Scientific novelty is a thorough study of the development of the market of hightech products of Ukraine, analysis of factors of influence and forecasting the prospects for its development.

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Schmitt-Radloff, Ulrich [Verfasser]. "Werkstoff- und Prozessentwicklung für funkenerosiv bearbeitbare ZTA Keramiken mit NbC- und TiC Dispersion / Ulrich Schmitt-Radloff." Aachen : Shaker, 2019. http://d-nb.info/1188550993/34.

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40

Tonello, Karolina Pereira dos Santos. "Compósitos de alumina com adições de NbC, TaC e TiC para aplicação em ferramentas de corte." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/85/85134/tde-29052013-092205/.

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No presente trabalho foram desenvolvidos compósitos à base de alumina, com adição de carbetos de metais de transição, NbC, TaC e TiC, como reforço. Os carbetos, na forma de partículas, foram adicionados em 1,5% em volume à matriz de alumina durante a moagem em attritor. O processamento foi realizado por moagem em attritor, secagem em rotoevaporadora e desaglomeração em peneira. A dinâmica de oxidação dos carbetos e das composições dos compósitos foi estudada para a definição de parâmetros de sinterização e processamento dos compósitos. A cinética de sinterização foi estudada por dilatometria, com taxa de 10°C/min. até 1600°C em atmosfera de ar sintético, e até 1800°C, em atmosfera de argônio, com esta etapa foi possível verificar que o NbC e o TiC dificultaram a sinterização da alumina e que o TaC auxiliou nos processos de retração. Nas amostras que foram sinterizadas em dilatômetro ao ar foram detectadas fases resultantes de fusão congruente nos compósitos Al2O3/NbC e Al2O3/TaC, foram também observadas evidências de formação de líquido no compósito com adição de TaC. Com base nesses resultados foram estudadas duas técnicas de produção das ferramentas de corte: prensagem uniaxial seguida de sinterização sem pressão e sinterização por prensagem a quente. Todas as amostras foram caracterizadas microestruturalmente e quanto às propriedades mecânicas, tendo-se determinado que as amostras produzidas por prensagem a quente possuem microestrutura mais controlada e propriedades mecânicas superiores às produzidas por sinterização sem pressão. Pelos processos estudados foi observado que os carbetos influenciam diferentemente a sinterização da alumina. De maneira geral a presença destas fases nos contornos de grãos promove alterações na microestrutura modificando o tamanho de grãos da alumina. Foi proposta a hipótese de que esse comportamento é afetado pela formação de uma camada superficial resultante da oxidação dos reforços, com isto, de acordo com os diagramas de fase é possível a formação de soluções sólidas entre alumina e Ta2O5 e Nb2O5 além da formação de fase líquida, estes mecanismos alterariam a mobilidade dos contornos de grão da alumina. Para o processamento das ferramentas de corte foi utilizada prensagem a quente, escolhido pelo critério da microestrutura e propriedades mecânicas. Os testes de usinagem foram realizados com ferramentas de corte de geometria quadrada, em peças de ferro fundido cinzento e vermicular. O tempo de vida útil da ferramenta produzida com o compósito Al2O3/ NbC foi 13% superior quando comparado à uma ferramenta cerâmica comercial no teste de usinagem de ferro fundido cinzento.
In the present work alumina based composites with addition of transition metal carbides, NbC, TaC and TiC as reinforcement phase were developed. The carbides, in particulate form, were added in 1.5vol.% on the alumina matrix during attritor milling. The processing was conducted by attritor milling, drying in a rotoevaporator and deagglomeration in sieve. The oxidation dynamics of carbides and composities were studied in order to define the sintering and processing parameter of composites. The sintering kinetics was studied by dilatometry at 10° C/min. up to 1600 ° C in synthetic air atmosphere and up to 1800°C in argon, with this step it was possible to verify that the NbC and TiC hindered the sintering of alumina and the TaC helped in the retraction process. In the sintered by dilatometer in air phases resultant from congruent melting on Al2O3/NbC and Al2O3/TaC composites were detected in the composite with TaC addition was also observed evidence of liquid phase. In the samples sintered in dilatometer in air were detected solid solutions on composites CN and CTa and evidence of liquid formation in the composite with TaC addition. Based on these results two techniques were studied in order to produce cutting tools: uniaxial pressing, followed by pressureless sintering and hot pressing. All samples were characterized by microstructure and mechanical properties, and it was shown that samples produced by hot pressing have more controlled microstructure and mechanical properties superior to those produced by pressureless sintering. With the studied processes it was observed that the carbides influence differently alumina sintering. Generally the presence of these phases at the grain boundary causes changes in the microstructure modifying alumina grain size alumina. The proposed hypothesis is that this behavior would be affected by the formation of a surface layer resulting from oxidation of reinforcements with that, according to the phase diagrams, it is possible to find solid solutions between alumina and Ta2O5 and Nb2O5 and possible formation of liquid phase, which alter the mobility of the grain boundary of alumina. Hot pressing was used for the processing of cutting tools, chosen due to the microstructure and mechanical properties. The machining tests were performed with square geometry cutting tools, in samples of gray cast iron and compacted graphite iron. The tool life of cutting tool produced with Al2O3 / NbC composite was 13% higher when compared to a commercial ceramic cutting tool on machining of gray cast iron.

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41

TONELLO, KAROLINA P. dos S. "Compósitos de alumina com adições de NbC, TaC e TiC para aplicação em ferramentas de corte." reponame:Repositório Institucional do IPEN, 2013. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10206.

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Tese (Doutoramento)
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

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42

Baetz, Delphine. "Transporteurs membranaires dépendants du sodium, NBC et NHE1 : activité et voies de régulation dans les cardiomyocytes." Paris 7, 2003. http://www.theses.fr/2003PA077133.

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43

Mello, Junior Murillo Menna Barreto de. "Estudo sobre o efeito dos par?metros de processamento dos p?s e sinteriza??o do a?o inox 316l refor?ado com NbC." Universidade Federal do Rio Grande do Norte, 2011. http://repositorio.ufrn.br:8080/jspui/handle/123456789/12722.

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This masther dissertation presents a contribution to the study of 316L stainless steel sintering aiming to study their behavior in the milling process and the effect of isotherm temperature on the microstructure and mechanical properties. The 316L stainless steel is a widely used alloy for their high corrosion resistance property. However its application is limited by the low wear resistance consequence of its low hardness. In previous work we analyzed the effect of sintering additives as NbC and TaC. This study aims at deepening the understanding of sintering, analyzing the effect of grinding on particle size and microstructure and the effect of heating rate and soaking time on the sintered microstructure and on their microhardness. Were milled 316L powders with NbC at 1, 5 and 24 hours respectively. Particulates were characterized by SEM and . Cylindrical samples height and diameter of 5.0 mm were compacted at 700 MPa. The sintering conditions were: heating rate 5, 10 and 15◦C/min, temperature 1000, 1100, 1200, 1290 and 1300◦C, and soaking times of 30 and 60min. The cooling rate was maintained at 25◦C/min. All samples were sintered in a vacuum furnace. The sintered microstructure were characterized by optical and electron microscopy as well as density and microhardness. It was observed that the milling process has an influence on sintering, as well as temperature. The major effect was caused by firing temperature, followed by the grinding and heating rate. In this case, the highest rates correspond to higher sintering.
O presente trabalho apresenta uma contribui??o ao estudo da sinteriza??o de um a?o inox 316 L, com o objetivo de estudar o seu comportamento frente ao processo de moagem e o efeito da temperatura de isoterma na sua microestrutura e propriedades mec?nicas. O a?o inox 316L ? uma liga largamente utilizada pela sua propriedade de alta resist?ncia ? corros?o. Contudo a sua aplica??o ? limitada pela baixa resist?ncia ao desgaste, consequ?ncia da sua baixa dureza. Em trabalhos anteriores, foi analisado o efeito da sinteriza??o empregando aditivos como NbC e TaC. Assim, este estudo visa aprofundar o conhecimento da sinteriza??o analisando o efeito do tempo da moagem sobre o tamanho da part?cula e a microestrutura do sinterizado e o efeito da taxa de aquecimento e isoterma sobre a microestrutura do sinterizado e sobre a sua microdureza. Para isso foram mo?dos p?s de a?o 316L com NbC em tempos de moagens de 1, 5 e 24 horas respectivamente. Os particulados foram caracterizados por MEV e EDS. Amostras cil?ndricas, com altura e di?metro de 5,0 mm foram compactadas a 700MPa. As condi??es de sinteriza??o foram: taxa de aquecimento de 5, 10 e 15◦C/min, a temperatura de 1000, 1100, 1200, 1290 e 1300◦C, e tempos de isoterma de 30 e 60min. A taxa de resfriamento foi mantida em 25◦C/min. Todas as amostras foram sinterizadas em forno a v?cuo. Os sinterizados foram caracterizados na sua microestrutura atrav?s de microscopia ?tica e eletr?nica al?m de densidade e microdureza Vickers. Foi observado que o processo de moagem tem influ?ncia na sinteriza??o, assim como a temperatura. O efeito maior foi provocado temperatura de queima, seguida pela moagem e taxa de aquecimento. Neste caso, as maiores taxas corresponde a maior sinteriza??o.

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44

ARAUJO, EDVAL G. "Influencia das adicoes de NBC e ligas a base de fosforo na sinterizacao do aco rapido M2." reponame:Repositório Institucional do IPEN, 1993. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10372.

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Dissertacao (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

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45

Damerval, Claire. "Contributions à l'étude du comportement mécanique des composites cotac γ /γ'-NbC à moyenne et haute température". Paris 11, 1986. http://www.theses.fr/1986PA112034.

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Cette thèse présente une étude du comportement des composites à fibres Cotac δ / δ’-NbC sous divers types de sollicitations mécaniques : fluage, traction transversale, cyclage thermique sous charge et fatigue oligo-cyclique. En fluage, nous avons montré que le transfert de charge de la matrice dans les fibres s'accompagne, dans le Cotac 784, d'un changement de mécanisme de déformation plastique de la matrice au cours d'un essai. D'autre part, nous avons étudié l'influence du mode de rupture des fibres sur l'allure des courbes de fluage, et mis en évidence l'influence de la résistance mécanique de la matrice sur les propriétés du composite. En traction transversale, l'analyse des mécanismes de rupture des Cotac 744 et 784 permet d'interpréter qualitativement l'évolution de leur ductilité avec la température, en terme de trois contraintes la limite élastique de la matrice, la contrainte de cohésion des joints de grains et la contrainte de clivage des lamelles de NbC. Une interprétation de l'augmentation de ductilité transversale obtenue grâce à une addition mineure de bore et à la formation d'un film de phase δ' aux joints de grains est proposée. En cyclage thermique sous charge, la chute de durée de vie provoquée par la superposition au fluage d'un cyclage de température s'élève à un facteur 3 environ à 1100°C ; ce phénomène s'est avéré non spécifique aux composites. En fatigue oligocyclique, le Cotac 784 a été caractérisé à 650°C en traction_compression à déformation imposée et une analyse succincte (phénoménologique et fractographique) de son comportement a été effectuée.

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46

Achouche, Mehdi. "L'Utopisme technologique dans la science-fiction hollywoodienne, 1982-2010 : transhumanisme, posthumanité et le rêve de "l'homme-machine"." Phd thesis, Université de Grenoble, 2011. http://tel.archives-ouvertes.fr/tel-00779615.

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La technologie et le progrès technologique occupent une place centrale dans l'histoire et dans l'imaginaire américain. En même temps que la Révolution Industrielle apparaissent aux États-Unis les premières réelles expressions d'un utopisme technologique loin de se confiner à la littérature ou à la seule fiction - la nation et le monde pourront bientôt être transformés pour le meilleur par la technologie américaine. La science-fiction s'emparera bientôt de l'idée, traduisant aujourd'hui encore un rêve et des valeurs étroitement associés à l'identité et au projet national et reposant au cœur de l'imaginaire du pays. Le techno-utopisme contemporain, s'il s'appuie sur la " convergence NBIC " (Nano-Bio-Info-Cogno), tend cependant à se focaliser sur les transformations du corps humain lui-même. Le mouvement transhumaniste, qui s'attend à une transformation radicale du monde (la Singularité) grâce notamment aux nanotechnologies et aux intelligences artificielles, met ainsi l'accent sur l'impact que pourraient avoir ces technologies, ainsi que les biotechnologies (ingénierie génétique, cellules souches, clonage), sur un corps et une conscience améliorés ou " augmentés ", ainsi que sur l'organisation sociale de demain. Tant est si bien qu'on ne pourrait bientôt plus parler d'humanité mais bien de posthumanité. Le cinéma de science-fiction hollywoodien, en tant que mode d'expression culturel central à la culture américaine moderne, met lui-même en scène et réfléchit ces rêves de sublimation et ces cauchemars de déshumanisation. Les films du corpus (les Tron, RoboCop, Star Trek First Contact et Insurrection, Gattaca, la trilogie Matrix, The 6th Day, The Island, The Surrogates, Terminator IV, les deux Iron Man, Avatar, notamment) proposent leurs propres versions successives des dilemmes liés aux avancées de demain mais aussi à l'interdépendance qui lie déjà les humains à leurs machines. Les acteurs en sont les machines elles-mêmes, ceux qui les contrôlent (le gouvernement fédéral, l'armée, les multinationales), les techno-utopistes et leurs ennemis Luddites, les scientifiques, les ingénieurs et les hackers, mais aussi une humanité fascinée presque malgré elle par la promesse technologique. Si cette dernière est souvent caricaturée, à Hollywood même, en un conflit opposant " technophiles " et " technophobes ", les choses sont, même au cinéma, loin d'être aussi simples, en particulier depuis les années 1980. Et si la libération de l'oppression technologique passait par la technologie elle-même ?

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47

Cline, Morgan Paige. "When the News is the News: A Textual Analysis of NBC and CBS networks' Response to Sexual Harassment Allegations in the Wake of the #MeToo Movement." Thesis, Virginia Tech, 2020. http://hdl.handle.net/10919/99204.

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As the #MeToo movement swept the nation from Hollywood to Washington, within less than a week's time in November of 2017, longstanding news anchors, Matt Lauer and Charlie Rose were fired from their respective news networks because of sexual harassment allegations. As a result, each network had to grapple with repairing a destroyed image while simultaneously fulfilling the duty to report on news objectively. This qualitative analysis examined NBC and CBS's response to the allegations of sexual harassment against each anchor, allegations of withholding information and allegations of ignoring complaints through the lens of image repair theory in order to identify if any of the strategies were present in the networks' response. Applications of image repair discourse to news media organizations is a relatively novel examination and it highlights the complex duality of an organization's right to uphold its image but obligation to present the news objectively, even when it has become the news.
Master of Arts
As the #MeToo movement swept the nation from Hollywood to Washington, within less than a week's time in November of 2017, longstanding news anchors, Matt Lauer and Charlie Rose were fired from their respective news networks because of sexual harassment allegations. As a result, each network had to grapple with repairing a destroyed image while simultaneously running business as usual. This study examined NBC and CBS's response to the allegations of sexual harassment against each anchor, the allegations of withholding information and allegations of ignoring complaints made by employees over the past two decades, all the while attempting to fulfill the duty of objectively reporting the news. This study examined each networks' response using a crisis communication theory and offers an extension to the theory that can be utilized by news network organizations and the like.

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Tribunella, Kari. "A content analysis of alcohol incidents on ABC, CBS, FOX, and NBC during prime-time television in 2001." Virtual Press, 2001. http://liblink.bsu.edu/uhtbin/catkey/1221307.

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Within the past twenty years, an abundant amount of research has been done on how alcohol advertising and alcohol portrayals affect society. The most common studies have examined the influence alcohol advertising and alcohol portrayals have or do not have on adolescents, the relationship between alcohol content and the level of consumption, and how adults and under-age drinkers perceive drinking incidents.The present study is a content analysis examining how four networks- ABC, CBS, FOX, and NBC vary in the amount of alcohol incidents shown in prime-time programming.The two-week study began on Sunday, May 20, 2001 and ended on Saturday, June 2, 2001 from 8 to 11 p.m. each evening. Alcohol incidents were classified as either a physical or verbal reference, as well as an appearance. Physical references were further categorized as the type of theme represented, the venue of the incident, and the type of drink involved.The findings suggest that the FOX and NBC networks air programs that present more alcohol incidents and themes of socialization than ABC and CBS. Therefore the researcher concludes that because of the target audience age is younger for FOX and NBC, these networks are more inclined to show more alcohol incidents and socialization themes versus the ABC and CBS networks, which have an older target viewing audience.
Department of Journalism

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49

PANELLI, RENATO. "Processamento do aco AISI M2 com adicao de 10 porcento vol. NbC utilizando a tecnica de mechanical alloying." reponame:Repositório Institucional do IPEN, 1999. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10748.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Dissertacao (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
FAPESP:96/08958-1

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50

Guiz, Robin. "Influence d’additions de titane/tungstène et de vanadium sur la précipitation de carbures secondaires au sein d’alliages modèles de type HP." Thesis, Lyon, 2016. http://www.theses.fr/2016LYSEM011/document.

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Les alliages de type HP constituent un matériau de choix pour l'élaboration des tubes de vaporeformage et de vapocraquage dans l'industrie pétrochimique. Exposés à des températures comprises entre 700°C et 1000°C sous des pressions gazeuses de plusieurs MPa, leur microstructure initiale associée à une fine précipitation secondaire, intervenant en cours de service, leur confèrent une excellente résistance aux mécanismes de fluage auxquels ils sont sujets. Néanmoins, à terme, la coalescence des précipités conduit à la dégradation rapide des tubes.Les effets de certains éléments d'alliages (V, Ti/W) sur la précipitation secondaire des carbures M23C6 et NbC ont été étudiés au travers de simulations via le logiciel TC-PRISMA. Sur la base de résultats prometteurs en termes d'optimisation des caractéristiques de la précipitation, deux alliages modèles ont été coulés au laboratoire et soumis à divers vieillissements dans la gamme de température correspondant aux conditions de service. Les microstructures de ces alliages ont d'abord été comparées à celle d'un alliage HP industriel de composition standard à l'état brut de coulée. La précipitation secondaire a par la suite été caractérisée au sein des trois alliages dans les différents états vieillis. Les investigations microstructurales ont permis de mettre en avant certains effets bénéfiques d'un ajout de vanadium et d'ajouts combinés de titane et de tungstène sur les caractéristiques de la précipitation secondaire
HP alloys are typically used as steam methane reforming tubes in the petrochemical industry. During service, they are exposed to temperatures between 700°C and 1000°C under gaz pressure of several MPa. Their as-cast microstructure, together with fine in-situ secondary precipitation, provide these alloys with an excellent resistance to creep deformation. Nevertheless, after long-time ageing, coarsening of secondary carbides leads to the weakening of the tubes and therefore to an accelerated damaging.The effects of some alloying elements (V, Ti/W) on secondary precipitation of M23C6 and NbC carbides were investigated through numerical simulations performed with TC-PRISMA software. On the basis of encouraging results in terms of precipitation optimization, two model HP-type alloys were cast at the laboratory and aged in the range of temperatures corresponding to service conditions. As-cast microstructures were first compared with an industrial "standard" alloy. Then, secondary precipitation were characterized for all the alloys and all ageing temperatures. Microstructural investigation highlighted the beneficial effect of vanadium and titanium/tungsten additions on secondary precipitation characteristics

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