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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

The Brownian motion of the NiO nano film on NaCl¡]100¡^and the coalescence of the overlapped nano films

Zheng, Wan-ting 20 August 2007 (has links)
none
12

Deposition of NiO/CGO films by EAVD method

Chang, Jun-liang 04 August 2004 (has links)
Abstract In this study, EAVD(Electrostatic Assisted Vapor Deposition) technique was used to fabricate NiO/CGO (Cerium Gadolinum Oxide) films for the anode of IT-SOFCs (Intermediate Temperature-Solid Oxide Fuel Cells). The objective of this work is to establish the relationship between the morphology of NiO/CGO films and deposition parameters. The effects of different deposition parameters on film morphology were studied. The systematically changed deposition parameters were : deposition temperature, deposition time, flow rate and concentration of precursor solution and substrate types. According to experiment results, deposition temperature and deposition time are most important deposition parameters of controlling the morphology of films. The deposited NiO/CGO films with a highly porous structure were obtained above 400 oC and 5mins. On the other hand, when deposition temperature and time were decreased below 400 oC and 5mns, dense films were obtained. In this study, the flow rate and concentration of precursor solution and substrate types also influence the morphology of films, although to a lesser degree. The most suitable range of the flow rate is 0.7 cc/hr to 1.4 cc/hr. The XRD results show that the crystalline NiO/CGO film were obtained by EAVD technique.
13

Ozoniza??o de sementes de girassol / Ozonation of sunflower seeds

Rodrigues, Vitor Oliveira 16 May 2014 (has links)
Submitted by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2016-01-05T17:37:15Z No. of bitstreams: 2 vitor_oliveira_rodrigues.pdf: 1888771 bytes, checksum: 2a13199fad989883502026feb4526f36 (MD5) license_rdf: 22974 bytes, checksum: 99c771d9f0b9c46790009b9874d49253 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2016-01-05T18:03:14Z (GMT) No. of bitstreams: 2 vitor_oliveira_rodrigues.pdf: 1888771 bytes, checksum: 2a13199fad989883502026feb4526f36 (MD5) license_rdf: 22974 bytes, checksum: 99c771d9f0b9c46790009b9874d49253 (MD5) / Made available in DSpace on 2016-01-05T18:03:14Z (GMT). No. of bitstreams: 2 vitor_oliveira_rodrigues.pdf: 1888771 bytes, checksum: 2a13199fad989883502026feb4526f36 (MD5) license_rdf: 22974 bytes, checksum: 99c771d9f0b9c46790009b9874d49253 (MD5) Previous issue date: 2014 / Funda??o de Amparo ? Pesquisa do estado de Minas Gerais (FAPEMIG) / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (Capes) / A cultura do girassol (Helianthus annuus L.) ? de grande import?ncia econ?mica, devido seu uso na produ??o agr?cola para a extra??o do ?leo, considerado, dentre os ?leos vegetais, como um dos ?leos de melhor qualidade nutricional al?m de possuir alta qualidade para a produ??o do biodiesel. Esta cultura apresenta um alto grau de adaptabilidade ?s varia??es edafoclim?ticas, ? tolerante ao d?ficit h?drico al?m de apresentar menor custo de produ??o que as outras oleaginosas, antevendo-se uma boa e nova op??o de renda aos produtores brasileiros. A propaga??o do girassol ? feita exclusivamente via semente e por isso ? importante a obten??o de sementes de alta qualidade gen?tica, f?sica, fisiol?gica e sanit?ria. Dentre os fatores que afetam a difus?o da cultura de girassol destaca-se a presen?a de doen?as causadas por v?rus bact?rias e fungos, j? que o girassol ? hospedeiro de uma vasta gama de microorganismos e cuja maioria pode ser transmitida via semente. Como alternativa de substitui??o da aplica??o de produtos quimicos, o oz?nio tem sido usado no controle de insetos-praga e de fungos em gr?os armazenados, al?m de ser utilizados em diversos outros seguimentos na elimina??o de microorganismos. Diante do exposto, objetivou-se avaliar a efici?ncia do oz?nio no controle de pat?genos em sementes de girassol. Foram utilizados tr?s lotes de sementes de girassol da cultivar Embrapa 122 de tr?s peneiras (3,5 mm; 4,0 mm e 5,5 mm). Para caracteriza??o do perfil dos lotes realizou-se a determina??o do grau de umidade, primeira contagem de germina??o, germina??o, ?ndice de velocidade de germina??o, emerg?ncia, estande inicial, ?ndice de velocidade de emerg?ncia e sanidade (incid?ncia e severidade). Para avaliar a a??o do oz?nio na sanitiza??o do girassol as sementes foram mantidas em ambiente rico em oz?nio pelos per?odos de 20 minutos, 60 minutos, 120 minutos e sem ozoniza??o (controle). Ap?s o tratamento com oz?nio, al?m dos testes citados anteriormente foram tamb?m realizados os testes de envelhecimento, tetraz?lio e sanidade. Conclui-se que o tratamento de sementes de girassol, cultivar Embrapa 122 com oz?nio na concentra??o de 1741 ppmv (0,24 g/h), por 60 minutos, reduz a popula??o f?ngica de Alternaria sp., Fusarium sp., Aspergillus sp. e Penicillium sp sem afetar o seu potencial fisiol?gico. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Produ??o Vegetal, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2014. / ABSTRACT The culture of sunflower (Helianthus annuus L.) is of wide economic importance because of its use in agricultural production for the extraction of oil, considered among the vegetable oils, as the oils of better nutritional quality besides having high quality production biodiesel This culture has a high degree of adaptability to changes in climate and soil, is tolerant to drought and presents lower production cost than other oilseeds, foreseeing a good new income option for Brazilian producers. The spread of sunflower is made exclusively by seed and so it is important to obtain high quality seed genetics, physical, physiological and sanitary. Among the factors affecting the diffusion of the sunflower crop stands the presence of diseases caused by viruses fungi and bacteria as the host sunflower is a wide range of microorganisms and that the large majority may be transmitted via seed. Alternatively replacement of applying chemicals, ozone has been used for controlling insect pests and fungi in stored grains, and are used in many other segments in eliminating microorganisms. Given the above, the objective was to evaluate the efficiency of ozone to control pathogens on sunflower seeds. Three lots of sunflower cultivar Embrapa 122 three sieves (3.5 mm, 4.0 mm and 5.5 mm) were used. To characterize the profile of lots was held to determine the degree of moisture content, the first germination, germination index, germination rate, emergence, initial stand, speed index and emergency health (incidence and severity). To evaluate the effect of ozone sanitization in sunflower seeds were kept in ozone-rich environment for periods of 20 minutes, 60 minutes, 120 minutes and without ozonation (control). After the treatment with ozone, besides the above-mentioned tests were also conducted aging tests, tetrazolium health. We conclude that treatment of sunflower seeds, Embrapa 122 with ozonated water 1741 ppmv (0.24 g/h) for 60 minutes reduces the fungal population of Alternaria sp., Fusarium sp., Aspergillus sp. and Penicillium sp without affecting their physiological potential.
14

Conception de nouveaux matériaux moléculaires pour l'élaboration de cellules photovoltaïques hybrides de type p à colorant

Farre, Yoann 21 October 2016 (has links)
Les travaux présentés dans cette thèse ont pour objectif de contribuer au développement des cellules photovoltaïques hybrides employant un colorant organique pour sensibiliser un semi-conducteur de type p (NiO). Ces travaux de recherche ont porté sur la synthèse, l’étude théorique par des calculs DFT, les caractérisations physico-chimiques (absorption, émission, électrochimie et spectro-électrochimie) et les mesures photovoltaïques de sensibilisateurs innovants. Des modulations de structures sur la base du motif dicétopyrrolopyrrole (DPP) ont permis d’étudier l’influence d’une entité électrodonneuse ainsi que le rôle crucial de différents groupes électroaccepteurs sur la durée de vie de l’état à charges séparées (NiO+/colorant-) et sur les performances photovoltaïques. L’intensification et l’élargissement des bandes d’absorption de nouveaux colorants fondés sur cette même famille de sensibilisateur (DPP) ont accru considérablement la densité de courant. L’étude de nouveaux matériaux organiques de type donneur-accepteur et l’application d’une stratégie employant deux groupes accepteurs successifs de forces croissantes ont été réalisées. Cette partie a mis en lumière la nécessité de développer de nouveaux groupes électrodonneurs et fonctions d’ancrage mieux adaptées aux p-DSSC. Cette problématique a été abordée par la conception de colorants de type pérylène-monoimide dont la structure varie uniquement par la nature de la fonction d’ancrage. Ces colorants ont été testés dans des cellules sur des cathodes poreuses de NiO et de CuGaO2 et ont pu montrer que la fonction hydroxyquinoline conduit à des performances photovoltaïques supérieures à la fonction acide carboxylique. / This thesis aims at contributing to the development of dye sensitized solar cells (DSSC) that are based on an organic dye and a p-type semi-conductor as photocathode such as NiO. In this context, these studies focus on the synthesis, the theoretical study by DFT calculations, the physicochemical characterizations (absorption and emission spectra, electrochemistry and spectroelectrochemistry) and photovoltaic characterizations of these innovative sensitizers. Structure modulations on a diketopyrrolopyrrole dye (DPP) investigate the influence of an electron-donating group and the crucial role of different electron-withdrawing groups on the lifetime of the charge separation state (NiO+/dye-) and on the photovoltaic performances. Enhancement and broadening of the absorption bands with new sensitizers have enabled to considerably increase the photocurrent density and to reach among the highest values reported in the literature with the best dyes. Synthesis of new organic push-pull dyes and the application of a strategy using two successive electron-withdrawing groups of growing strengths have been realized. This part highlights the necessity to develop new electron-donating and anchoring groups for p-type dye sensitized solar cells. This point issue was investigated in the final chapter of this thesis by the design of new perylene monoimide sensitizers, whose structures only differ by the nature of the anchoring group (CO2H, acac, PO3H2, hydroxyquinoline…). These dyes were investigated in DSSCs with porous cathode made of NiO or CuGaO2. It was shown that the binding group hydroxyquinoline gives higher photovoltaic performances than the classical carboxylic acid group.
15

Efeito da fonte de nitrog?nio na libera??o de OH-/H+ na rizosfera e a intera??o com toxidez de alum?nio, estresse de salinidade e associa??o com Trichoderma sp. / Effect of nitrogen supply in release of OH-/ H+in the rhizosphere and interaction with aluminum toxicity, salinity stress and association with Trichoderma sp

Silva, Aldir Carlos 19 December 2013 (has links)
Submitted by Celso Magalhaes (celsomagalhaes@ufrrj.br) on 2017-05-12T11:45:17Z No. of bitstreams: 1 2013 - Aldir Carlos da Silva.pdf: 2147745 bytes, checksum: 9bf6569c9f3905b19282cebf10a5b003 (MD5) / Made available in DSpace on 2017-05-12T11:45:17Z (GMT). No. of bitstreams: 1 2013 - Aldir Carlos da Silva.pdf: 2147745 bytes, checksum: 9bf6569c9f3905b19282cebf10a5b003 (MD5) Previous issue date: 2013-12-19 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico - CNPq / The present study was conducted to evaluate if changes in rhizosphere pH of the growth media, controlled by the use of nitrogen sources could alleviate aluminum toxicity or effects caused by salinization. It is well documented that if a plant is absorbing and assimilating nitrate as a nitrogen source, it releases 0H - for growth substrate. If she is absorbing, assimilating, ammonia source releases H+. This occurs because the cells need to balance its electrochemical charge balance due to differential uptake of cations and anions. Despite being a general rule, scientific research directly use the nitrogen source in the growth medium, few have used other methods to add these sources, such as foliar application of nitrogen and its implications on load balancing. In this work, several alternative management of nitrogen application and its interactions with the toxicity caused by aluminum, excess salts and Trichoderma were studied. Sunflower (Helianthus annuus L.), Passionflower (Passiflora edulis f flavicarpa L.), Pineapple (Ananas comosus Merril), Coffee (Coffea arabica L), Almond (Terminalia catapa Linn) and Sombrero (Clitoria fairchildiana Howard). To conduct studies with plants Sunflower was initially performed a selection of more tolerant to acidity and salinity plants. The experiments were conducted on various substrates, soil and sand, simple and complete nutrient solution. The interaction between Trichoderma x nitrogen source for plants was conducted with Passion fruit and Sunflower. Were selected as moderately tolerant to aluminum to grow Sunflower Helium 360 , the other cultivars to toxicity occurred in contraction equal to or superior 160?M aluminum . Was selected as tolerant to salinity the H?lio 251 > 250 > 253, cultivars, with concentrations above 25 mM NaCl (1.90 dS.m?) plants were stop grown. After this step prior experiments cultivars tolerant or sensitive were used in accordance with the experimental needs. The experiments were divided into the following steps: In the first step, we evaluated the release of OH - / H + with application of nitrogen sources directly in the growth medium, and found that the nitrogen sources were unable to minimize the toxic effects of aluminum and salinity. In the second experiment, the effects of the release OH- /H+ with application of nitrogen sources in the association of the fungus Trichoderma sp. This fungus grown in petri dishes only at pH values above 5.0. The release of OH- / H+ did not influence the association of the fungus with the roots of plants of sunflower and Passion fruit. In the third step, we assessed whether foliar application of nitrogen sources could produce the same effects on efflux of loads in the rhizosphere. It was found that the nitrogen sources applied foliar increased the pH of the solution was applied when 10 % of nitrate and reduced the pH when applied 5 % and 10 % ammonium sulfate in plants of Coffee and 10 % of nitrate in Sunflower . The foliar application of nitrogen sources did not alter the toxicity of aluminum and not the salt effect on plants and Sunflower Coffee. / O presente trabalho foi realizado com o objetivo de estudar se varia??es do pH da rizosfera e do meio de crescimento, controladas pelo uso de fontes nitrogenadas, poderiam amenizar a toxidez de alum?nio ou os efeitos provocados pela saliniza??o. Na literatura cientifica ? bem documentado que se uma planta esta absorvendo e assimilando nitrato como uma fonte nitrogenada, ela libera 0H- para o substrato de crescimento. Se ela esta absorvendo e assimilando uma fonte amoniacal libera H+. Isto ocorre devido ?s c?lulas necessitarem equilibrar o seu balan?o eletroqu?mico de carga, devido ? assimila??o diferenciada de c?tions e anions. Apesar de ser uma regra geral, os trabalhos cient?ficos usam a fonte nitrogenada diretamente no meio de crescimento, poucos utilizaram outros m?todos de adicionar estas fontes, como por exemplo, a aplica??o foliar de nitrog?nio e suas implica??es no balan?o de carga. Neste trabalho foram estudadas diversas alternativas de aplica??o de nitrog?nio e as suas intera??es com a toxidez provocada por alum?nio, excesso de sais e com o fungo Trichoderma. Foram estudas diversas plantas: Girassol (Helianthus annuus L), Maracuj? (Passiflora edulis f. flavicarpa L.), Abacaxi (Ananas comosus Merril), Caf? (Coffea arabica L), Amendoeira (Terminalia catapa Linn) e Sombreiro (Clitoria fairchildiana Howard). Para realizar os estudos com plantas de Girassol foi realizada inicialmente uma sele??o de plantas mais tolerantes a acidez e a salinidade. Os experimentos foram realizados em diversos substratos, solo, areia, solu??o nutritiva simples e completa. A intera??o entre fungo Trichoderma x fonte nitrogenada foi realizado para plantas de Girassol e Maracuj?. Foram selecionadas como medianamente tolerantes ao alum?nio a cultivar de Girassol H?lio 360, as demais cultivares a toxidez ocorreu em contra??o igual ou superiora 160?M de alum?nio. Foi selecionada como tolerante a salinidade as cultivares H?lio 251>250>253, com concentra??es acima 25mM de NaCl (1,90 dS.m?) as plantas n?o cresceram.Ap?s esta etapa foram implantados experimentos com as cultivares previamente selecionas como sens?veis ou tolerantes e estas foram utilizadas de acordo com a necessidade experimental. Os experimentos foram divididos nas seguintes etapas: Na primeira etapa, avaliou-se a libera??o do OH-/H+ com aplica??o das fontes nitrogenadas diretamente no meio de crescimento, sendo verificado que as fontes nitrogenadas n?o conseguiram minimizar os efeitos t?xicos do alum?nio e da salinidade. Na segunda etapa, avaliou-se os efeitos libera??o do OH-/H+ com aplica??o das fontes nitrogenadas na associa??o do fungo Trichoderma. Este fungo cresceu em placas de petri somente em valores de pH acima de 5,0. A libera??o de OH-/H+ n?o influenciou a associa??o do fungo com as ra?zes de plantas de Girassol e Maracuj?. Na terceira etapa, foi avaliado se a aplica??o foliar das fontes nitrogenadas poderia produzir os mesmos os efeitos nos efluxos de cargas na rizosfera. Foi verificado que as fontes nitrogenadas aplicadas via foliar aumentaram o pH da solu??o quando foi aplicado 10% de nitrato e reduziram o pH quando foi aplicado 5% e 10% de sulfato de am?nia em plantas de Caf? e com 10% de nitrato em Girassol. A aplica??o foliar de fontes nitrogenadas n?o alteraram a toxidez de alum?nio e nem do efeito salino em plantas de Caf? e Girassol.
16

Modelos Estruturais in Silico e Express??o de Quimeras da Gonadotrofina Cori??nica Equina

Amaral, F??bio de Barros 31 March 2014 (has links)
Submitted by Kelson Anthony de Menezes (kelson@ucb.br) on 2016-12-19T19:37:39Z No. of bitstreams: 1 FabiodeBarrosAmaralDissertacao2014.pdf: 2938215 bytes, checksum: 3d899bf568eeae36d21979ba7aafab3c (MD5) / Made available in DSpace on 2016-12-19T19:37:39Z (GMT). No. of bitstreams: 1 FabiodeBarrosAmaralDissertacao2014.pdf: 2938215 bytes, checksum: 3d899bf568eeae36d21979ba7aafab3c (MD5) Previous issue date: 2014-03-31 / The equine chorionic gonadotropin (eCG) has been used as an important resource in the processes of reproduction in animals of economic interest, especially horses and cattle. The eCG molecule consists of a glycoprotein composed of two subunits called alpha and beta which together perform the function of both LH (luteinizing hormone) and FSH (follicle stimulating hormone) and due to this characteristic has great potential to induce ovulation in household species. Based on the aforementioned characteristics, the present work was was aimed at the study and characterization of the structure of eCG using molecular modeling techniques as well as testing its production in cells of the microorganism Pichia pastoris. Furthermore, chimeric models have been proposed linking the eCG and immunoglobulin G (IgG) molecule based on studies that reveal the great potential of it in raising the half-life of other molecules circulating in the organism. Four chimeric models were prepared so that the eCG alpha and beta chains are connected by a hinge, short and flexible regions, while the terminal region of the alpha chain was connected to the N-terminal portion of the CH2 domain of the IgG by another hinge region, thus resulting in a model in which two different molecules are linked. / A gonadotrofina cori??nica equina (eCG) tem sido um importante recurso usado nos processos de reprodu????o em animais de interesse econ??mico, principalmente equinos e bovinos. A mol??cula de eCG consiste em uma glicoprote??na composta de duas subunidades denominadas alfa e beta que juntas desempenham a fun????o tanto de LH (horm??nio luteinizante) como FSH (horm??nio fol??culo estimulante) e devido a essa caracter??stica possui um grande potencial para induzir a ovula????o em esp??cies dom??sticas. Baseando-se nas caracter??sticas citadas, o presente trabalho teve como objetivo estudar e caracterizar a estrutura do eCG utilizando-se t??cnicas de modelagem molecular assim como testar a sua produ????o em c??lulas do microrganismo Pichia pastoris. Al??m disso, foram propostos modelos quim??ricos ligando eCG ?? mol??cula de imunoglobulina G (IgG) tendo como base estudos que revelam o grande potencial da mesma em elevar a meia vida de outras mol??culas em circula????o no organismo. Quatro modelos quim??ricos foram apresentados de forma que as cadeias beta e alfa do eCG s??o conectadas por regi??es hinge que s??o sequ??ncias curtas e flex??veis da mol??cula enquanto que a regi??o terminal da cadeia alfa foi conectada por meio de outra regi??o hinge, ?? por????o N-terminal do dom??nio CH2 da IgG, portanto, resultando em um modelo em que est??o ligadas duas mol??culas diferentes.
17

Särskrivning : En studie som belyser elevtexter från år nio med fokus på betyg och förekomsten av särskrivning

Christoph, Caroline January 2007 (has links)
<p>Denna studie har som syfte att belysa elevtexter från år nio med fokus på betyg och hur vanligt förekommande särskrivning är. Materialet består av elevtexter från de nationella proven 2003. Elevtexterna är indelade i tre grupper efter betyg och varje grupp består av tio texter. Analyser av elevtexter avser att verifiera eller falsifiera hypotesen om att lågpresterande elever gör mer särskrivningar än högpresterande elever.</p><p>Resultatet visar att särskrivning förekommer i samtliga undersökningsgrupper. Elever med underkänt och elever med godkänt betyg gör relativt lika många särskrivningar och avsevärt fler än elever med mycket väl godkänt. Undersökningen visar dessutom att högpresterande elever vanligtvis särskriver två sammansatta substantiv, medan lågpresterande elever även gör särskrivningar på ord som inleds med ett förstärkningsprefix.</p><p>En slutsats som kan göras är att hypotesen kan verifieras. Vidare kan utläsas att pedagogen till viss del accepterar särskrivning i det svenska språket. Bedömningen av nationella prov bygger på övergripande färdigheter som bland annat läsförståelse och problemlösning, därför är det av stor betydelse att undervisningen pedagogen bedriver problematiserar stavning och grammatik. Har eleverna tagit till sig kunskapen i undervisningen kan pedagogen se ett en utveckling vid bedömning av nationella prov.</p>
18

Un modèle génératif pour le développement de serveurs Internet

Loyauté, Gautier 05 September 2008 (has links) (PDF)
Les serveurs Internet sont des logiciels particuliers. Ils doivent répondre aux demandes d'un grand nombre de clients distants, supporter leur évolution et être robustes car ils ne s'arrêtent jamais. Les modèles de concurrence permettent d'entrelacer les traitements d'un grand nombre de clients. Aucun consensus ne se dégage sur un meilleur modèle. Pour s'abstraire du modèle de concurrence, je propose un modèle de développement de serveurs Internet. Les outils de vérification formelle permettent d'accroître la sûreté des logiciels mais il est nécessaire de leur fournir un modèle simple du logiciel. Le modèle de développement que je propose est utilisé pour générer le serveur et son modèle formel. Le décodage d'une requête cliente dépend du modèle de concurrence. Je propose d'utiliser un générateur d'analyseur syntaxique qui s'abstrait de ce problème et automatise le développement du décodage
19

Sangue, suor e l?grimas : problemas, perspectivas e desafios na preserva??o do patrim?nio arqueol?gico em licenciamentos ambientais

Gomes, Josiane Fialho Gon?alves 21 June 2018 (has links)
Submitted by PPG Hist?ria (historia-pg@pucrs.br) on 2018-06-29T19:43:05Z No. of bitstreams: 1 DISSERT_MESTR_PUCRS_JGOMES_2018.pdf: 8760337 bytes, checksum: 06e36415003ff8d7748f423486dbab15 (MD5) / Approved for entry into archive by Sheila Dias (sheila.dias@pucrs.br) on 2018-07-09T13:38:17Z (GMT) No. of bitstreams: 1 DISSERT_MESTR_PUCRS_JGOMES_2018.pdf: 8760337 bytes, checksum: 06e36415003ff8d7748f423486dbab15 (MD5) / Made available in DSpace on 2018-07-09T13:45:43Z (GMT). No. of bitstreams: 1 DISSERT_MESTR_PUCRS_JGOMES_2018.pdf: 8760337 bytes, checksum: 06e36415003ff8d7748f423486dbab15 (MD5) Previous issue date: 2018-06-21 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / The present study aims to highlight, reflect and make a critical analysis of the existing problems and barriers for the preservation and management of the archaeological heritage (GPA), in the environmental licensing process at the State level, in context of Normative Instruction (IN) n? 01/2015, since it was ?building?, as well as the perspectives, the progress and the challenges yet to be faced. Methodologically, searches were conducted on the main conceptual aspects necessary for the full understanding of the GPA, addressed the regulations for the preservation and the actors involved. The description of the process of "building" of the new rule was made possible through the monitoring of the facts at the time, as well as analyze several news and articles published in different media, documents and articles. Events were held, in addition to the demonstrations and discussions highlighted. Were discussed the procedures for the participation of the Instituto do Patrim?nio Hist?rico e Art?stico Nacional (IPHAN) in previous and current licenses, as well as of environmental licensing and the relationship between them. The research carried out and the analysis of NI, allowed the identification and analysis of barriers and problems of all kinds in the current context, as well as of the main positive aspects, beyond the view of the author, corroborated with the IPHAN, the Sociedade de Arqueologia Brasileira (SAB), some selected researchers and the community. Among the main problems are the failure in joint, communication and compatibility of interests among the actors in GPA and the lack of participation of the IPHAN in environmental licensing. Knowledge of problematic, of events, of the new legislation in force and the proposals in processing in the Conselho Nacional de Meio Ambiente (CONAMA), made possible an overview of the progress and the future, considered the prospects and challenges for the implementation and effectiveness of the GPA. Was evidenced the need of adopting measures and urgent actions to change this scenario with so many problems, whose time is worrying through the large and looming threats of changes in licensing rules, which will certainly shake Archaeology as a whole, asking: what will be the next bureaucracy and problems? It will be the end of Archaeology of Contract? / O presente estudo possui como objetivo evidenciar, refletir e efetuar a an?lise cr?tica dos entraves e da problem?tica existente para a preserva??o e a gest?o do patrim?nio arqueol?gico (GPA), nos processos de licenciamentos ambientais no ?mbito estadual, no contexto da Instru??o Normativa (IN) n? 01/2015, desde a sua ?constru??o?, bem como acerca das perspectivas, dos avan?os e dos desafios a serem enfrentados. Metodologicamente, foram efetuadas pesquisas acerca dos aspectos conceituais principais necess?rios ao pleno entendimento da GPA, abordada a regulamenta??o para a preserva??o e os atores envolvidos. A descri??o do processo de ?constru??o? da nova normativa foi possibilitada por meio do acompanhamento dos fatos na ?poca, bem como analisadas not?cias e mat?rias publicadas em distintas m?dias, documentos, artigos e eventos realizados, al?m das manifesta??es e debates evidenciados. Foram tratados ainda dos procedimentos para a participa??o do Instituto do Patrim?nio Hist?rico e Art?stico Nacional (IPHAN) nos licenciamentos, anteriores e atuais, assim como dos licenciamentos ambientais e a rela??o entre ambos. As pesquisas efetuadas e a aprecia??o da IN permitiram a identifica??o e a an?lise de entraves e problemas de toda ordem no contexto atual, assim como dos principais aspectos positivos, para al?m experi?ncia e da vis?o da autora, corroborada com a do IPHAN, da Sociedade de Arqueologia Brasileira (SAB), de pesquisadores e da comunidade arqueol?gica. Dentre os principais problemas, est?o a falha na articula??o, comunica??o e compatibiliza??o de interesses entre os atores na GPA e a falta de participa??o do IPHAN nos licenciamentos ambientais. O conhecimento da problem?tica, de fatos ocorridos, das novas legisla??es em vigor e das propostas em tramita??o no Congresso Nacional e no Conselho Nacional de Meio Ambiente (CONAMA), possibilitaram um panorama dos avan?os e do futuro, consideradas as perspectivas e os desafios para a efetiva??o e a efic?cia da GPA. Foi evidenciada a necessidade de ado??o de medidas e a??es urgentes para a mudan?a deste quadro com tantos problemas, cujo momento ? preocupante mediante as grandes e iminentes amea?as de altera??es nas regras dos licenciamentos, que certamente ir?o abalar a Arqueologia como um todo, questionando-se: Quais ser?o as pr?ximas burocracias e problemas? Ser? o fim sum?rio da Arqueologia de Contrato?
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Estudo de rotas de síntese e processamento cerâmico do compósito NiO-YSZ para aplicação como anodo em células a combustível do tipo óxido sólido / Study of synthesis routes and processing of NiO-YSZ ceramic composite for use as anode in solid oxide fuel cell (SOFC)

Walter Kenji Yoshito 17 March 2011 (has links)
Este estudo visa a definição de condições de síntese e processamento cerâmico que possibilitem a obtenção do componente anódico com características adequadas para a operação de uma SOFC (Solid Oxide Fuel Cell), ou seja, boa distribuição microestrutural do NiO na matriz de YSZ e porosidade cerca de 30% após redução de NiO. As rotas de síntese selecionadas englobaram a coprecipitação em meio amoniacal, mistura mecânica dos pós e combustão a partir de sais de nitrato. As técnicas de caracterização de pós empregadas incluíram a difração de raios X, microscopia eletrônica de varredura, microscopia eletrônica de transmissão, difração a laser, adsorção gasosa (BET) e picnometria de hélio. Os resultados obtidos indicaram que empregando-se a técnica de coprecipitação, a perda de Ni2+, na forma de complexo [Ni(NH3)n]2+, pode ser minimizada pelo controle do pH em 9,3, mantendo-se a concentração de Ni2+ na solução inicial em 0,1M. No método de mistura mecânica a melhor condição de dispersão dos pós, sem a sedimentação diferencial, foi obtida para valores de potencial zeta em pH 8,0, fixando-se a concentração de dispersante em 0,8% em massa. Na síntese por combustão observou-se que para composições pobres em combustível, os produtos finais apresentaram-se amorfos e com alta área superficial (120,2 m2.g-1). Para as composições ricas em combustível, uréia, os pós obtidos apresentaram-se cristalinos sendo que a intensidade das reflexões do padrão de DRX aumenta com o aumento do excesso de combustível, devido ao aumento da temperatura de reação. No estudo de sinterabilidade dos compactados preparados a partir de pós preparados pelos três métodos determinou-se a temperatura ao redor de 1300 ºC para máxima taxa de densificação e porosidade entre 6,0 e 14%. Os resultados da redução em atmosfera de H2 dos compósitos confirmam que a cinética de reação ocorre em duas etapas, sendo que a primeira etapa com comportamento linear é controlada por reação química na superfície. Na segunda etapa a redução passa a ser controlada pela difusão do gás nos micros poros, gerados pela redução do NiO, diminuindo a taxa de redução. / This study aim the definition of synthesis and ceramic processing conditions of the anodic component suitable for operation of SOFC, i.e, homogeneous distribution of NiO in YSZ matrix and porosity after reduction above 30%. The selected synthesis routes included the co-precipitation in ammonia media, mechanical mixing of powders and combustion reaction from nitrate salts. The characterization techniques of powders included the X-ray diffraction, scanning and transmission electron microscopy, laser diffraction, nitrogen gas adsorption technique (BET) and Helium pycnometry. The obtained results indicated that the loss of Ni2+ in co-precipitation process, due to the formation of complex [Ni(NH3)n]2+, can be minimized by controlling the pH around 9.3, keeping the concentration of nickel cation in the solution to be precipitated around 0.1M. In the mechanical mixing method the best condition of powder dispersion, without differential sedimentation, was obtained for zeta potential values at pH around 8.0, fixing the dispersant concentration at 0.8%. For the combustion synthesis it was observed that when stoichiometric and twofold stoichiometric urea was used, amorphous phase was formed and a higher surface area was attained in the final products. Employing the fuel-rich solution condition, crystallization of the powder was observed and the relative intensity of reflections of XRD patterns increased with excess of fuel, due to increasing the reaction temperature. Sinterability studies of pellets prepared from powder synthesized by the three routes described above showed the temperature around 1300 º C for maximum rate densification and porosity between 6.0 and 14%. Reduction results of the composites confirmed that the reduction kinetics occurs in two steps. The first one with a linear behavior and controlled by chemical reaction on the surface. The second reduction step is the reduction that is controlled by gas diffusion in micro pores, generated by reduction of nickel oxide, decreasing the rate of reduction.

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