Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-06-21T19:35:53Z No. of bitstreams: 1 AluisioIgorRegoFontes_TESE.pdf: 3702181 bytes, checksum: ebee4d30550394d35c706823dc2169ae (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-06-22T21:45:56Z (GMT) No. of bitstreams: 1 AluisioIgorRegoFontes_TESE.pdf: 3702181 bytes, checksum: ebee4d30550394d35c706823dc2169ae (MD5) / Made available in DSpace on 2016-06-22T21:45:56Z (GMT). No. of bitstreams: 1 AluisioIgorRegoFontes_TESE.pdf: 3702181 bytes, checksum: ebee4d30550394d35c706823dc2169ae (MD5) Previous issue date: 2015-09-11 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / A extra??o de informa??es de sinais aleat?rios ? um problema frequente e relevante em muitas aplica??es de processamento digital de sinais. Nos ?ltimos anos, diferentes m?todos t?m sido utilizados para a parametriza??o de sinais ou obten??o de descritores eficientes de suas caracter?sticas. Quando os sinais aleat?rios possuem propriedades es- tat?sticas cicloestacion?rias, as Fun??es de Autocorrela??o C?clica (CAF) e a Densidade Espectral C?clica (SCD) podem ser utilizadas na obten??o de informa??es cicloestacion?- rias de segunda ordem. Entretanto, em sinais n?o-gaussianos, as informa??es cicloestaci- on?rias de segunda ordem s?o fracas e, neste caso a an?lise cicloestacion?ria deve ocorrer sobre informa??es estat?sticas de ordem superior. Este trabalho prop?e uma nova ferra- menta matem?tica para a an?lise cicloestacion?ria de ordem superior baseada na fun??o de correntropia. Especificamente, a teoria de an?lise cicloestacion?ria ? revisitada sob um enfoque de teoria da informa??o, e as Fun??es de Correntropia C?clica (CCF) e Densidade Espectral de Correntropia C?clica (CCSD) s?o definidas. ? comprovado analiticamente que a CCF cont?m informa??es de momentos cicloestacion?rios de segunda ordem e de ordem superior, sendo uma generaliza??o da CAF. O desempenho dessas novas fun??es, na extra??o de caracter?sticas cicloestacion?rias de ordem superior, ? analisado em um cen?rio de comunica??o sem fio com ru?do n?o-gaussiano. / Information extraction is a frequent and relevant problem in digital signal processing. In the past few years, different methods have been utilized for the parameterization of signals and the achievement of efficient descriptors. When the signals possess statistical cyclostationary properties, the Cyclic Autocorrelation Function (CAF) and the Spectral Cyclic Density (SCD) can be used to extract second-order cyclostationary information. However, second-order cyclostationary information is poor in nongaussian signals, as the cyclostationary analysis in this case should comprise higher-order statistical information. This paper proposes a new mathematical tool for the higher-order cyclostationary analysis based on the correntropy function. Specifically, the cyclostationary analysis is revisited focusing on the information theory, while the Cyclic Correntropy Function (CCF) and Cyclic Correntropy Spectral Density (CCSD) are also defined. Besides, it is analytically proven that the CCF contains information regarding second- and higher-order cyclostationary moments, being a generalization of the CAF. The performance of the aforementioned new functions in the extraction of higher-order cyclostationary characteristics is analyzed in a wireless communication system where nongaussian noise exists.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-12-15T18:09:01Z No. of bitstreams: 1 TalesViniciusRodriguesDeOliveiraCamara_DISSERT.pdf: 3587261 bytes, checksum: ddffd176ad921074a281b50e904134f5 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-12-28T19:00:56Z (GMT) No. of bitstreams: 1 TalesViniciusRodriguesDeOliveiraCamara_DISSERT.pdf: 3587261 bytes, checksum: ddffd176ad921074a281b50e904134f5 (MD5) / Made available in DSpace on 2016-12-28T19:00:57Z (GMT). No. of bitstreams: 1 TalesViniciusRodriguesDeOliveiraCamara_DISSERT.pdf: 3587261 bytes, checksum: ddffd176ad921074a281b50e904134f5 (MD5) Previous issue date: 2016-04-25 / T?cnicas de Classifica??o Autom?tica de Modula??o (AMC) t?m sido utilizadas por sistemas modernos de comunica??o para otimizar o uso do espectro e com isso aumen- tar as taxas de transmiss?o de dados. No processo de AMC, v?rias arquiteturas podem ser utilizadas para retirar informa??o e avaliar caracter?sticas do sinal modulado em um canal. Uma grande parte dessas arquiteturas s?o constru?das utilizando como base a ci- cloestacionariedade. A an?lise cicloestacion?ria ? realizada por meio das ferramentas: Fun??o de Autocorrela??o C?clica (CAF) e Fun??o Densidade Espectral C?clica (SCD). Esta ultima particularmente, ? utilizada para observar as caracter?sticas cicloestacion?rias de diferentes sinais, as quais s?o chamadas de assinaturas. Embora tenha v?rias aplica- ??es bem sucedidas no ?mbito de AMC, a cicloestacionariedade possui restri??es pois a CAF e SCD s?o limitadas ? an?lise estat?stica de segunda ordem, devido ao uso da correla??o com cerne de sua express?o. Com o objetivo de generalizar a avalia??o da cicloestacionariedade sobre infinitos momentos estat?sticos de um sinal, surgem Fun??o de Autocorrentropia C?clica (CCAF) e a Fun??o Densidade Espectral de Correntropia C?clica (CCSD). Tais fun??es s?o fundamentadas no c?lculo da correntropia. Neste tra- balho a CCSD ser? investigada quanto capacidade de gerar assinaturas para diferentes modula??es e seu potencial de uso em AMC ser? avaliado. / The steady growth in the use of wireless communication systems has contributed to finding new ways to exploit the maximum capacity of use spectrum. In this context, cognitive radios appear as an appropriate option able to offer an efficient use of the channel, ensuring greater bandwidth to users. In the scenario of cognitive radios, cyclostationary analysis techniques have shown to be quite effective in extracting features that can be used in the spectrum sensing. Such features called cyclostationary signatures are generated by the spectral correlation density function (SCD) and can be directly associated with the type of modulation used on the channel. Architectures for spectrum sensing using SCD has good performed when used in AWGN channels. However, recent studies show that the tool doesn?t have a good performance in the extraction of signal characteristics contaminated with impulsive noise (Outlier), because it is limited to second order statistical analysis. In order to generalize the SCD cyclostationary analysis for endless statistical moments, arise the function correntropy cyclic spectral density (CCSD) This work proposes a spectrum sensing architecture using CCSD, which is applied to the extraction cyclostationary features from digital modulations: ASK, FSK, BPSK, QPSK and MSK. The sensing architecture proposed is evaluated in various parameters: different sensing thresholds, change of SNR levels of a AWGN channel, different kernel sizes (s) from CCSD and extraction of cyclostationary features from modulations contaminated with noise impulsive. The results of this study demonstrate the effectiveness of the proposed architecture.

Made available in DSpace on 2014-12-17T15:41:55Z (GMT). No. of bitstreams: 1 DanielleOM_DISSERT.pdf: 1963445 bytes, checksum: 143b241474d5026def897c0c4c0d797f (MD5) Previous issue date: 2011-07-12 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / In this work were synthesized and studied the spectroscopic and electrochemical characteristics of the coordination compounds trans-[Co (cyclam)Cl2]Cl, trans- Na[Co(cyclam)(tios)2], trans-[Co(en)2Cl2]Cl and trans-Na[Co(en)2(tios)2], where tios = thiosulfate and en = ethylenediamine. The compounds were characterized by: Elemental Analysis (CHN), Absorption Spectroscopy in the Infrared (IR), Uv-Visible Absorption Spectroscopy, Luminescence Spectroscopy and Electrochemistry (cyclic voltammetry). Elemental Analysis (CHN) suggests the following structures for the complex: trans- [Co(cyclam)Cl2]Cl.6H2O and trans-Na[Co(cyclam)(tios)2].7H2O. The electrochemical analysis, when compared the cathodic potential (Ec) processes of the complexes trans- [Co(cyclam)Cl2]Cl and trans-[Co(en)2Cl2]Cl, indicated a more negative value (-655 mV) for the second complex, suggesting a greater electron donation to the metal center in this complex which can be attributed to a greater proximity of the nitrogen atoms of ethylenediamine in relation to metal-nitrogen cyclam. Due to the effect of setting macrocyclic ring to the metal center, the metal-nitrogen bound in the cyclam are not as close as the ethylenediamine, this fact became these two ligands different. Similar behavior is also observed for complexes in which the chlorides are replaced by thiosulfate ligand, trans-Na[Co(en)2(tios)2] (-640 mV) and trans-Na[Co(cyclam)(tios)2] (-376 mV). In absorption spectroscopy in the UV-visible, there is the band of charge transfer LMCT (ligand p d* the metal) in the trans-Na[Co(cyclam)(tios)2] (350 nm, p tios  d* Co3+) and in the trans-Na[Co(en)2(tios)2] (333 nm, p tios d* Co3+), that present higher wavelength compared to complex precursor trans- [Co(cyclam)Cl2]Cl (318 nm, pCl  d* Co3+), indicating a facility of electron density transfer for the metal in the complex with the thiosulfate ligand. The infrared analysis showed the coordination of the thiosulfate ligand to the metal by bands in the region (620-635 cm-1), features that prove the monodentate coordination via the sulfur atom. The νN-H bands of the complexes with ethylenediamine are (3283 and 3267 cm-1) and the complex with cyclam bands are (3213 and 3133 cm-1). The luminescence spectrum of the trans-Na[Co(cyclam)(tios)2] present charge transfer band at 397 nm and bands dd at 438, 450, 467, 481 and 492 nm. / Este trabalho teve por objetivo sintetizar e estudar as caracter?sticas espectrosc?picas e eletroqu?micas dos compostos de coordena??o trans- Na[Co(cyclam)(tios)2], trans-[Co(cyclam)Cl2]Cl, trans-[Co(en)2Cl2]Cl e trans- Na[Co(en)2(tios)2], em que tios = tiossulfato e en = etilenodiamina. Os compostos obtidos foram caracterizados por: An?lise elementar (CHN), Espectroscopia de Absor??o na Regi?o do Infravermelho (IV), Espectroscopia de Absor??o na Regi?o do UV-Vis?vel, Espectroscopia de Luminesc?ncia e Eletroqu?mica (voltametria c?clica). A an?lise elementar (CHN) sugere as seguintes estruturas para os complexos: trans- [Co(cyclam)Cl2]Cl.6H2O e trans-Na[Co(cyclam)(tios)2].7H2O. Na an?lise eletroqu?mica, ao se fazer uma compara??o dos potenciais cat?dicos (Ec) referentes aos processos de redu??o dos complexos trans-[Co(cyclam)Cl2]Cl e trans-[Co(en)2Cl2]Cl, observa-se valores mais negativos (-655 mV) no segundo complexo, sugerindo uma maior doa??o eletr?nica ao centro met?lico neste complexo o que pode ser atribu?do a uma maior proximidade dos ?tomos de nitrog?nio da etilenodiamina em rela??o a liga??o metal nitrog?nio do cyclam, devido ao efeito do ajuste do anel macroc?clico ao centro met?lico (efeito macroc?clico), o que faz com que a liga??o metal-nitrog?nio n?o seja t?o pr?xima quanto da etilenodiamina, fato que difere os ligantes em estudo. Comportamento similar ? tamb?m observado para os complexos, em que os cloretos s?o substitu?dos pelo ligante tiossulfato, trans-Na[Co(en)2(tios)2] (-640 mV) e trans- Na[Co(cyclam)(tios)2] (- 376 mV). Na espectroscopia de absor??o na regi?o do UVvis?vel observa-se a banda de transfer?ncia de carga LMCT (pdo ligante d* do metal), como sendo a de maior comprimento de onda para o trans- Na[Co(cyclam)(tios)2] (350 nm, ptios d* Co3+) e trans-Na[Co(en)2(tios)2] (333 nm, ptios d* Co3+) comparativamente ao complexo precursor, trans- [Co(cyclam)Cl2]Cl (318 nm, pCl- d* Co3+) indicando uma maior facilidade de transfer?ncia de densidade eletr?nica para o metal nos complexos com o ligante tiossulfato. Na an?lise de infravermelho observou-se a coordena??o do ligante tiossulfato ao metal nos complexos atrav?s de bandas na regi?o de 620-635 cm-1, caracter?sticas que comprovam a forma monodentada de coordena??o via ?tomo de enxofre e a perman?ncia das bandas νN-H para complexos com etilenodiamina, bandas em 3283 e 3267 cm-1, e complexos com o cyclam, bandas em 3213 e 3133 cm-1. Na an?lise de luminesc?ncia foi observada uma banda de transfer?ncia de carga em 397 nm e bandas d-d no espectro de emiss?o do complexo trans-Na[Co(cyclam)(tios)2] em 438, 450, 467, 481 e 492 nm.

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-06-26T18:12:15Z No. of bitstreams: 1 2016 - Fabr?cia Ferreira e Ferreira.pdf: 1846980 bytes, checksum: c127e17162c67e64b719801f92b0c6fc (MD5) / Made available in DSpace on 2017-06-26T18:12:15Z (GMT). No. of bitstreams: 1 2016 - Fabr?cia Ferreira e Ferreira.pdf: 1846980 bytes, checksum: c127e17162c67e64b719801f92b0c6fc (MD5) Previous issue date: 2016-03-23 / Canine demodicosis is an inflammatory skin disease, frequently diagnosed in veterinary clinics, caused by the proliferation of mites of the species Demodex sp. In recent years, important findings about the disease have been reported, mainly aspects related to treatment, with the insertion of new molecules or new treatment regimens. Doramectin is a macrocyclic lactone that has been used empirically by veterinarians, who use different routes, doses and intervals in its administration, with no homogeneus results. This study aimed to evaluate the use of doramectin in the treatment of dogs affected by the generalized form of demodicosis. Of the forty-six dogs diagnosed with the disease during the study, 20 were selected for the study and divided into three groups: Group I ? treated with doramectin at a dose of 600 mcg/kg once a week orally, group II ? treated at a dose of 300 mcg/kg orally every 3 days and group III ? treated at a dose of 600 mcg/kg every 7 days subcutaneously. The animals were treated until three consecutive negative skin scrapings were obtained, with intervals of at least fifteen days between them (parasitological cure). The days required to obtain the parasitological cure were 105, 82 and 100 according to the indicated groups; and their treatment efficiencies were 75, 100 and 83%, respectively. Doramectin was effective in treating generalized demodectic mange in dogs, regardless of the dose, route and interval of administration. However, the best results were obtained in the group treated at a dose of 300 mcg/kg orally every 3 days. There were no reported adverse reactions with the use of macrocyclic lactone. / Demodiciose canina ? uma doen?a inflamat?ria da pele, frequentemente diagnosticada nos consult?rios veterin?rios, causada pela prolifera??o de ?caros da esp?cie Demodex sp. Nos ?ltimos anos, importantes descobertas sobre a doen?a foram reportadas, principalmente os aspectos relacionados ao tratamento, com a inser??o de novas mol?culas ou novos esquemas de tratamento. A doramectina ? uma lactona macroc?clica que vem sendo usada de forma emp?rica por m?dicos veterin?rios, que a utilizam por diferentes vias, doses e intervalos na sua administra??o, com resultados heterog?neos. O objetivo do estudo foi avaliar a utiliza??o da doramectina no tratamento da demodiciose generalizada em c?es. Dos 46 animais diagnosticados com a doen?a, 20 foram selecionados e divididos em tr?s grupos experimentais: grupo I ? tratado com doramectina dose de 600 mcg/kg semanalmente por via oral, grupo II ? tratado na dose de 300 mcg/ kg por via oral a cada 3 dias e o grupo III ? tratado na dose de 600 mcg/kg a cada 7 dias por via subcut?nea. Os animais foram tratados at? a obten??o de tr?s raspados negativos consecutivos com pelo menos 15 dias de intervalo entre eles (cura parasitol?gica). Os dias necess?rios para obten??o da cura parasitol?gica foram 105, 82 e 100 de acordo com os grupos assinalados e as respectivas efic?cias ao tratamento foram 75, 100 e 83%. A doramectina demonstrou ser eficaz no tratamento da demodiciose generalizada em c?es independente da dose, via e intervalo de sua administra??o. Entretanto, os melhores resultados obtidos foram observados no grupo tratado com a dose de 300 mcg/ kg por via oral a cada 3 dias. N?o foram reportadas quaisquer rea??es adversas com a utiliza??o da lactona macroc?clica.

Made available in DSpace on 2014-12-17T15:01:22Z (GMT). No. of bitstreams: 1 GertrudesOQ.pdf: 1545154 bytes, checksum: 8733f5db29d9ddd6780de7e34160f375 (MD5) Previous issue date: 2005-12-16 / Thermal methods made heavy oil production possible in fields where primary recovery failed. Throughout the years steam injection became one of the most important alternatives to increase heavy oil recovery. There are many types of steam injection, and one of them is the cyclic steam injection, which has been used with success in several countries, including Brazil. The process involves three phases: firstly, steam is injected, inside of the producing well; secondly, the well is closed (soak period); and finally, the well is put back into production. These steps constitute one cycle. The cycle is repeated several times until economical production limit is reached. Usually, independent of reservoir type, as the number of cycles increases the cyclic injection turns less efficient. This work aims to analyze rock and reservoir property influence in the cyclic steam injection. The objective was to study the ideal number of cycles and, consequently, process optimization. Simulations were realized using the STARS simulator from the CMG group based in a proposed reservoir model. It was observed that the reservoir thickness was the most important parameter in the process performance, whilst soaking time influence was not significant / Os m?todos t?rmicos viabilizaram a produ??o de ?leo pesado em campos considerados n?o comerciais pelos m?todos convencionais de recupera??o. A inje??o de vapor, em particular, veio a se consagrar ao longo dos anos e ? hoje uma das principais alternativas economicamente vi?vel para o aumento da recupera??o dos ?leos pesados. Dentre as ramifica??es da inje??o de vapor existentes a inje??o c?clica tem sido utilizada com sucesso em escalas comerciais em v?rios pa?ses, incluindo o Brasil. O processo envolve tr?s fases: a primeira ? a inje??o de vapor na qual o vapor ? injetado, dentro do po?o produtor, por um per?odo espec?fico de tempo; em seguida, o po?o ? fechado por um curto per?odo de tempo ( soak period ); e finalmente, o po?o ? recolocado em produ??o durante meses a anos. Esse processo constitui um ciclo. O ciclo ? repetido um n?mero de vezes at? que o limite econ?mico na produ??o seja alcan?ado. Independente do tipo de reservat?rio, a inje??o c?clica geralmente se torna menos eficiente ? propor??o que o n?mero de ciclos aumenta. Este trabalho visa analisar a influ?ncia de algumas propriedades de rocha e reservat?rio na inje??o c?clica de vapor a fim de estudar o n?mero ideal de ciclos e, conseq?entemente, otimizar o processo. Foram realizadas simula??es, utilizando o simulador STARS do grupo CMG, a partir de um modelo de reservat?rio proposto. Observou-se que o efeito da espessura do reservat?rio foi o par?metro que mais influenciou no desempenho do processo, enquanto que para o tempo de soaking essa influ?ncia n?o foi significativa

Submitted by PPG Odontologia (odontologia-pg@pucrs.br) on 2018-03-09T17:05:54Z No. of bitstreams: 1 ROSANGELA_MELLO_VIEIRA_DIS.pdf: 2509683 bytes, checksum: 029b2e55766a406fa01c070281169016 (MD5) / Approved for entry into archive by Tatiana Lopes (tatiana.lopes@pucrs.br) on 2018-03-14T12:03:02Z (GMT) No. of bitstreams: 1 ROSANGELA_MELLO_VIEIRA_DIS.pdf: 2509683 bytes, checksum: 029b2e55766a406fa01c070281169016 (MD5) / Made available in DSpace on 2018-03-14T12:12:44Z (GMT). No. of bitstreams: 1 ROSANGELA_MELLO_VIEIRA_DIS.pdf: 2509683 bytes, checksum: 029b2e55766a406fa01c070281169016 (MD5) Previous issue date: 2018-01-18 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Introduction: The fracture of nickel titanium endodontic instruments may have a negative impact on the prognosis of the treatment, mainly because it blocks or prevents access to the root canal system in all its extension, compromising its modeling and sanification. Results from in vitro studies suggest that reciprocating motion can reduce the risks of torsion fracture and cyclic fatigue of NiTi instruments, compared to the continuous rotation movement. However, most of the studies that evaluate fracture resistance of instruments in reciprocating and rotational motion are in vitro studies, the generation of evidence of which is limited in comparison to the level of evidence generated by clinical studies in humans. Therefore, the present systematic review investigated whether the available evidence supports the hypothesis that reciprocating motion results in a lower clinical incidence of NiTi limb fracture as compared to rotational kinematics. Methodology: The PubMed, Embase, Isi Web of Science and Cochrane Library databases were searched until August 2017, without language restriction. In addition to the electronic searches, manual searches were made for additional references in specific chapters of relevant books in the area and also search in the gray literature. Based on the inclusion and exclusion criteria, two reviewers independently assessed the quality of each study based on the NewCastle Ottawa scale. The main exposure variable was the type of kinematics used to prepare the root canal (continuous or reciprocating) and the primary outcome variable was determined by the incidence of fracture of NiTi instruments in endodontic treatments. The incidence of fracture was recorded, having as unit of analysis: patients, teeth, instruments or channels. Other confounding variables collected included: country, year of publication, study design, type of system, group of teeth, number of sessions, operator and number of uses of NiTi instruments. The sources of heterogeneity were explored and the bi and multivariate meta logistic regression were performed to calculate the pooled estimates - odds ratios (OR) and 95% CI - for the incidence of instrument fracture, assessing the role of primary exposure and co- as moderators of the outcome. Results: Among the 737 articles initially identified, after the duplicates were removed, 39 comprised the final quantitative analysis, of which 32 reported the use of continuous rotation and 7 the use of reciprocating kinematics. Thirty-seven studies were included in the meta regression (N = 48,405 instruments). The aggregate clinical incidence of fracture of NiTi files was 2.43%, being 2.62% for continuous rotational movement and 0.4% for reciprocating kinematics. In the bivariate analysis, continuous rotational motion showed a greater incidence of fracture in relation to the reciprocating kinematics (OR = 6.39, 95% CI = 1.10-36.9), and the other associated covariates (p <0.05) with the incidence of fracture were: year of publication, operator and number of uses of the instruments. The multivariate models revealed that the number of uses of NiTi files in> 1 tooth (OR = 6.46, 95% CI = 1.42-29.3) and that general clinical operators (OR = 11.8, 95% CI = 1.49-93.5) were independently associated with a higher incidence of fracture of NiTi files, whereas kinematics was non-significant (OR = 1.56, 95% CI= 0.24-10, 0) after the settings. Conclusions: Available evidence from observational studies is limited but consistent, suggesting that reciprocating kinematics is associated with a lower incidence of fracture of NiTi files when compared to continuous rotation. In addition, the results revealed that other related clinical factors to the abilities of the operator,to the number of uses of the NiTi instruments, and to the advances in alloy composition as well as in the design of the files, have proved to be more relevant factors for fracture prevention than the type of kinematics employed. / Introdu??o: A fratura de instrumentos endod?nticos de n?quel tit?nio pode ter um impacto negativo no progn?stico do tratamento, sobretudo por bloquear ou impedir o acesso ao sistema de canais radiculares em toda sua extens?o, comprometendo a sua modelagem e sanifica??o. Resultados de estudos in vitro sugerem que o movimento reciprocante pode reduzir os riscos de fratura por tors?o e fadiga c?clica dos instrumentos de NiTi, comparado ao movimento de rota??o cont?nua. Ainda assim, a maioria dos estudos que avaliam a resist?ncia ? fratura de instrumentos no movimento reciprocante e rotat?rio s?o estudos in vitro, cuja gera??o de evid?ncias ? limitada em compara??o ao n?vel de evid?ncia gerada por estudos cl?nicos em humanos. Portanto, a presente revis?o sistem?tica investigou se a evid?ncia dispon?vel suporta a hip?tese de que o movimento reciprocante resulta em uma menor incid?ncia cl?nica de fratura de limas de NiTi, em compara??o com a cinem?tica rotat?ria. Metodologia: Foram pesquisadas as bases de dados PubMed, Embase, Isi Web of Science e Cochrane Library at? agosto de 2017, sem restri??o de idiomas. Al?m das buscas eletr?nicas foram realizadas buscas manuais por refer?ncias adicionais em cap?tulos espec?ficos de livros relevantes na ?rea e tamb?m busca na literatura cinza. Com base nos crit?rios de inclus?o e exclus?o, dois revisores avaliaram independentemente a qualidade de cada estudo com base na escala de NewCastle Ottawa. A principal vari?vel de exposi??o foi o tipo de cinem?tica empregada para o preparo do canal radicular (rotat?ria cont?nua ou reciprocante) e a vari?vel de desfecho prim?rio foi determinada pela incid?ncia de fratura de instrumentos de NiTi em tratamentos endod?nticos. A incid?ncia de fratura foi registrada, tendo como unidade de an?lise: pacientes, dentes, instrumentos ou canais. Outras vari?veis de confundimento coletadas incluiram: pa?s, ano de publica??o, desenho do estudo, tipo de sistema, grupo de dentes, n?mero de sess?es, operador e n?mero de usos dos instrumentos de NiTi. As fontes de heterogeneidade foram exploradas e a meta regress?o log?stica bi e multivariada foram realizadas para calcular as estimativas agrupadas ? odds ratios (OR) e 95%IC ? para a incid?ncia de fratura de instrumentos, avaliando o papel da exposi??o principal e das co-vari?veis, como moderadores do desfecho. Resultados: Entre os 737 artigos inicialmente identificados, ap?s remo??o das duplicatas, 39 compuseram a an?lise quantitativa final, dos quais 32 reportavam o uso de rota??o cont?nua e 7 o uso de cinem?tica reciprocante. Trinta e sete estudos foram inclu?dos na meta regress?o (N=48.405 instrumentos). A incid?ncia cl?nica agregada de fratura de limas de NiTi foi de 2,43%, sendo de 2,62% para o movimento rotat?rio cont?nuo e de 0,4% para a cinem?tica reciprocante. Na an?lise bivariada, o movimento rotat?rio cont?nuo demonstrou uma incid?ncia maior de fratura em rela??o ? cinem?tica reciprocante (OR=6,39, IC95%=1,10- 36,9), e as outras covari?veis associadas (p<0,05) com a incid?ncia de fratura foram: ano de publica??o, operador e n?mero de usos dos instrumentos. Os modelos multivariados revelaram que o n?mero de usos de limas de NiTi em >1 dente (OR=6,46, IC95%=1,42-29,3) e que operadores cl?nicos gerais (OR=11,8, IC95%=1,49-93,5) foram associados de modo independente com uma maior incid?ncia de fratura de limas de NiTi, enquanto que a cinem?tica demonstrou-se n?o-significante (OR=1,56, IC95%=0,24-10,0) ap?s os ajustes. Conclus?es: A evid?ncia dispon?vel, oriunda de estudos observacionais, ? limitada por?m consistente, sugerindo que a cinem?tica reciprocante est? associada com uma menor incid?ncia de fratura de limas de NiTi, quando comparada ao movimento de rota??o cont?nua. Al?m disso, os resultados revelaram que outros fatores cl?nicos relacionados ?s habilidades do operador, ao n?mero de usos dos instrumentos de NiTi, e aos avan?os na composi??o das ligas bem como no desenho das limas, demonstraram ser fatores mais relevantes para a preven??o da fratura do que o tipo de cinem?tica empregada.

Made available in DSpace on 2014-12-17T14:08:43Z (GMT). No. of bitstreams: 1 TiagoPC_DISSERT.pdf: 1471839 bytes, checksum: 916c40a19572e874803d077f6852a370 (MD5) Previous issue date: 2010-09-18 / In Brazilian Northeast there are reservoirs with heavy oil, which use steam flooding as a recovery method. This process allows to reduce oil viscosity, increasing its mobility and consequently its oil recovery. Steam injection is a thermal method and can occurs in continues or cyclic form. Cyclic steam stimulation (CSS) can be repeated several times. Each cycle consisting of three stages: steam injection, soaking time and production phase. CSS becomes less efficient with an increase of number of cycles. Thus, this work aims to study the influence of compositional models in cyclic steam injection and the effects of some parameters, such like: flow injection, steam quality and temperature of steam injected, analyzing the influence of pseudocomponents numbers on oil rate, cumulative oil, oil recovery and simulation time. In the situations analyzed was compared the model of fluid of three phases and three components known as Blackoil . Simulations were done using commercial software (CMG), it was analyzed a homogeneous reservoir with characteristics similar to those found in Brazilian Northeast. It was observed that an increase of components number, increase the time spent in simulation. As for analyzed parameters, it appears that the steam rate, and steam quality has influence on cumulative oil and oil recovery. The number of components did not a lot influenced on oil recovery, however it has influenced on gas production / No Nordeste brasileiro existem reservat?rios de ?leos pesados, nos quais se utiliza a inje??o de vapor como m?todo de recupera??o. Este processo permite diminuir a viscosidade do ?leo, aumentando a sua mobilidade e melhorando o volume de ?leo a ser recuperado. A inje??o de vapor ? um m?todo t?rmico e ocorre na forma cont?nua ou c?clica. A inje??o c?clica de vapor pode ser repetida diversas vezes. Cada ciclo consiste de tr?s etapas distintas: a fase de inje??o, fase de fechamento (soaking) e fase de produ??o. A inje??o c?clica se torna menos eficiente ? medida que o n?mero de ciclos aumenta. Neste sentido, este trabalho visa estudar a influ?ncia de modelos composicionais na inje??o c?clica de vapor e os efeitos de alguns par?metros, tais como: vaz?o de inje??o, qualidade do vapor e temperatura do vapor injetado; analisando a influ?ncia do n?mero de pseudocomponentes, no que diz respeito ? vaz?o de ?leo, produ??o acumulada de ?leo, fator de recupera??o e tempo de simula??o. Nas situa??es analisadas foi comparado o modelo de fluido de tr?s fases e tr?s componentes conhecido como Black-oil . Foram realizadas simula??es, utilizando um simulador comercial a partir de um modelo de reservat?rio homog?neo com caracter?sticas similares ?s encontradas no Nordeste brasileiro. Observou-se que quanto maior o n?mero de componentes, maior ? o tempo gasto na simula??o. J? para os par?metros analisados, verifica-se que a vaz?o de inje??o de vapor e a qualidade do vapor influenciam na produ??o acumulada de ?leo e no fator de recupera??o. O n?mero de componentes n?o exerceu muita influ?ncia na produ??o acumulada, nem no fator de recupera??o de ?leo, por?m foi significativa na produ??o de g?s do sistema

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-02-21T00:17:08Z No. of bitstreams: 1 FelipeDaSilvaPereiraAlbuquerqueOliveira_DISSERT.pdf: 6576373 bytes, checksum: b11e6d9b4401f339a1102a38b4351fa4 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-03-03T22:40:49Z (GMT) No. of bitstreams: 1 FelipeDaSilvaPereiraAlbuquerqueOliveira_DISSERT.pdf: 6576373 bytes, checksum: b11e6d9b4401f339a1102a38b4351fa4 (MD5) / Made available in DSpace on 2017-03-03T22:40:49Z (GMT). No. of bitstreams: 1 FelipeDaSilvaPereiraAlbuquerqueOliveira_DISSERT.pdf: 6576373 bytes, checksum: b11e6d9b4401f339a1102a38b4351fa4 (MD5) Previous issue date: 2016-09-12 / Em campos de ?leo pesado onde se utilize a inje??o c?clica de vapor, uma das tarefas mais recorrentes, demoradas e importantes ? a defini??o do cronograma de estimula??o com vapor para as centenas de po?os produtores. A capacidade de gera??o de vapor ? usualmente limitada e ainda mais reduzida pelas recorrentes manuten??es dos geradores. Esse agendamento at? poderia ser feito a partir de um modelo num?rico, mas al?m de exigir a disponibilidade de infraestrutura computacional, s? ? vi?vel caso o tempo n?o seja um fator cr?tico nessa defini??o. A indisponibilidade de tempo para rodar as simula??es necess?rias para a otimiza??o ? normalmente um empecilho, haja vista que a tarefa deve ser recorrentemente realizada conforme as premissas evoluem no tempo. Por isso, a op??o mais comum ? aproveitar a experi?ncia do engenheiro e do ge?logo de reservat?rios em uma an?lise subjetiva dos par?metros de reservat?rio e hist?rico de produ??o, muitas vezes levando em considera??o um estudo feito para um po?o representativo daquele campo ou de uma ?rea do campo. Esse m?todo tem se mostrado eficaz, embora consuma razo?vel quantidade de tempo para an?lise das op??es e conte com a intui??o do profissional encarregado da tarefa. Muitas s?o as refer?ncias acad?micas sobre modelos anal?ticos para representar o processo de inje??o c?clica de vapor e, de posse desses modelos, foram publicadas tentativas de us?-los para maximizar os resultados da estimula??o de determinado po?o. Entretanto, abordaram o problema restrito de uma estimula??o em particular, sem que o problema da defini??o de qual po?o estimular a cada momento de disponibilidade do recurso cr?tico, que ? a capacidade instalada de gera??o de vapor. Esta disserta??o prop?e, portanto, uma nova metodologia sobre como combinar a simplicidade dos diversos modelos anal?ticos dispon?veis na literatura com a grande capacidade computacional moderna para realizar uma an?lise probabil?stica do melhor retorno econ?mico para a capacidade instalada de gera??o de vapor, podendo servir de base, inclusive, na an?lise de viabilidade econ?mica para aquisi??o de maior capacidade ou para mobilizar geradores entre campos ou entre ?reas de um mesmo campo. S?o tratados os aspectos te?ricos dos modelos anal?ticos incluindo as limita??es inerentes a alguns deles bem como em quais circunst?ncias a aplica??o teria mais confiabilidade al?m de poss?veis adapta??es que mitigariam algumas das preocupa??es sobre a aplicabilidade desses modelos. Ao inv?s de definir uma combina??o de modelo e estrat?gia que seja conveniente para todos os cen?rios de utiliza??o poss?vel, trata-se de uma sugest?o de metodologia a fim de alcan?ar melhores resultados, cabendo a quem for us?-la definir quais s?o as particularidades do caso concreto e buscar modelos e estrat?gias que convierem. Por fim, ganhos potenciais ficam claros com a compara??o dos resultados obtidos pelo m?todo com a op??o subjetiva mais intuitiva de injetar nos po?os seguindo uma ordem trivial com cotas fixas para um caso te?rico padr?o atrav?s da simula??o num?rica, para qual ser? utilizado o simulador STARS? da CMG para simula??o t?rmica. / Heavy oil fields that produce through cyclic steam stimulation often demands one very recurrent, time consuming and important task during its lifetime: stimulation scheduling along the hundreds of the existing wells. Installed steam generation capacity is usually lower than the demand and is diminished even more by maintenance stoppages. This scheduling could be defined using numerical simulation, but beyond demanding a computational infrastructure, the time needed to complete the task is usually much greater than the time available. Computational infrastructure is not usually an issue but time availability in order to run the numerous simulations necessary to complete the optimization task, as it is commonly recurrent as circumstances change as time passes. Therefore, the most common option has been to make use of the skills and experience the reservoir engineer and geoscientists gathered during their careers. Using historical production data and reservoir parameters in a subjective analysis, taking into account local experiences extrapolated to the adjacent area or even to the whole field, the reservoir team defines which order the stimulation should be done. That method has shown to be effective, but it takes time to be done and depends on the professional intuition. Many academic references describe analytical models that tries to represent the cyclic steam stimulation and using those models, some attempts were made in order to maximize the results of the stimulation of each well, regardless the of the critical resource usage optimization. This research proposes an unseen methodology versing about how to combine the simplicity of the numerous analytical models available and the amazing modern computational power in order to complete a probabilistic analysis of the optimum financial return that could be reached with the installed steam generation facilities. It can also be used to sustain decisions regarding either investing in capacity enlargement or transfer between fields or production areas. Analytical models theoretical aspects are discussed, including application limitations and in which circumstances one can have better confidence using them as well as which adaptations can be done to diminish lacks of fitting. Instead of defining a model and strategy combination that would fit every scenario, it is more likely a suggestion of a methodology that aims better results. Therefore, it is up to the evaluator to recognize which the characteristics of the real case are and choose a model and a strategy that better complies with the case. Finally, potential gains become clear as results from the methodology are compared with those obtained from an intuitive approach for a standard case through numerical simulation using Computer Modelling Group?s thermal simulator STARS?.

Made available in DSpace on 2016-04-04T18:36:41Z (GMT). No. of bitstreams: 1 Leonardo Cassa de Oliveira.pdf: 1112623 bytes, checksum: 3380a5d2c962baef4c467adc48cabcf2 (MD5) Previous issue date: 2004-10-27 / This present dissertation proposal was to demonstrate, theoretically, that the innovations result from a Cyclical Relation, and establish a critical reflection comparing the presuppositions and practices to the generation of innovations and the organization s present thought, which priories productivity gains with costs reduction, specially with people. It s an exploratory research based in bibliographical revision. The critical analysis of notorious theoreticians permitted to verify that innovation determines the existent economic order and, consequently, the direction that the organizations should follow in the search for extraordinary gains or simply survival. Innovation results from a Cyclical Relation that involves information, people, and consequent creation, sharing and knowledge combination. Empirical studies analysis demonstrated that management practices oriented to organizational learning and knowledge creation provide a great extent in the generation of innovations and announce an organization that prioritizes the human interaction and time dedication to the learning process. On the other hand, the present productivity thought potencializes automated organizations with the least of people interacting. The final perspective indicates that the reflection about this dilemma is not a simple, direct and immediate answer to the way that should be followed, but contributes to visualize that it s necessary to change the present thought. / O presente trabalho teve por objetivo demonstrar teoricamente que as inova??es decorrem de uma Rela??o C?clica e, com isso, estabelecer uma reflex?o cr?tica comparando os pressupostos e pr?ticas para a gera??o de inova??es e o pensamento vigente das organiza??es, o qual prioriza ganhos de produtividade com redu??o de custos, especialmente com pessoas. Trata-se de um estudo de natureza explorat?ria baseado em pesquisa bibliogr?fica. A an?lise cr?tica de te?ricos reconhecidos permitiu verificar que a inova??o determina a ordem econ?mica existente e, por conseq??ncia, a dire??o que as organiza??es devem seguir na busca por ganhos extraordin?rios ou simplesmente sobreviv?ncia. A inova??o decorre de uma Rela??o C?clica que envolve informa??o, pessoas e, conseq?ente cria??o, compartilhamento e combina??o de conhecimentos. Estudos emp?ricos analisados demonstraram que pr?ticas gerenciais orientadas para a aprendizagem organizacional e cria??o de conhecimentos proporcionam maior amplitude na gera??o de inova??es e anunciam uma organiza??o que prioriza a intera??o humana e a dedica??o de tempo ao aprendizado. Por outro lado, o pensamento vigente de produtividade potencializa organiza??es automatizadas com o m?nimo de pessoas interagindo. A perspectiva final aponta que a reflex?o sobre esse dilema n?o se traduz numa resposta simples, direta e imediata para o caminho que deve ser seguido, mas contribui para visualizar que ? necess?rio mudar o pensamento vigente.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-10-18T20:55:14Z No. of bitstreams: 1 WendellRossineMedeirosDeSouza_TESE.pdf: 7150800 bytes, checksum: 939215abfa16589e581080cb1d3e85f5 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-10-24T23:17:21Z (GMT) No. of bitstreams: 1 WendellRossineMedeirosDeSouza_TESE.pdf: 7150800 bytes, checksum: 939215abfa16589e581080cb1d3e85f5 (MD5) / Made available in DSpace on 2017-10-24T23:17:22Z (GMT). No. of bitstreams: 1 WendellRossineMedeirosDeSouza_TESE.pdf: 7150800 bytes, checksum: 939215abfa16589e581080cb1d3e85f5 (MD5) Previous issue date: 2017-05-30 / A exposi??o dos po?os de petr?leo a condi??es extremas os tem levado a in?meros problemas de integridade, mesmo quando projetados adequadamente. O uso de t?cnicas de recupera??o, tal como a inje??o c?clica de vapor, submete os materiais a varia??es de temperatura severas reduzindo a vida ?til do po?o; ainda, podendo levar ? falha do revestimento met?lico e da bainha de cimento. A perda da integridade da bainha de cimento pode acarretar no vazamento dos fluidos presentes na forma??o e, em alguns casos, ocasionando significantes preju?zos ambientais e econ?micos. No caso de po?os sujeitos ? inje??o c?clica de vapor, a resist?ncia, a flexibilidade e as propriedades t?rmicas t?m sido apontadas como chave do problema. Neste trabalho, as an?lises termomec?nicas foram realizadas utilizando o m?todo dos elementos finitos em modo transiente. O revestimento met?lico, a bainha de cimento e a forma??o foram modelados utilizando-se um modelo 2D axissim?trico com elementos quadril?teros de 8 n?s. Foi analisado o comportamento mec?nico de bainha de cimento, sendo tr?s formula??es de pastas estudadas: pasta de refer?ncia e mais duas aditivadas com l?tex em concentra??es de 125 e 250 ml/kg de cimento. A influ?ncia da espessura da bainha de cimento e a taxa de aquecimento foram observadas como tamb?m seis diferentes valores de coeficientes de expans?o t?rmica para pasta de cimento. Foram analisados gradientes de temperaturas distintos de 150 oC, 200 oC, 250 oC, 300 oC e 350 oC, t?picas temperaturas encontradas no processo de inje??o de vapor, bem como em meio a forma??es com v?rios n?veis de rigidez. O estudo evidenciou que um dos problemas da integridade da bainha de cimento devido a inje??o de vapor est? associado a fase de aquecimento do po?o e localizado na regi?o da bainha pr?ximo ? forma??o. Foi constatado que vincular o emprego da formula??o mais flex?vel e expansiva a uma aplica??o do gradiente de temperatura de modo mais lento, pode prevenir o surgimento de danos na bainha de cimento evitando manobras de recimenta??o. Tal procedimento se mostrou eficaz para meios rochosos mais r?gidos bem como para temperaturas alvo mais elevadas. / Exposure of oil wells to extreme conditions has led to numerous integrity issues, even when designed properly. The use of recovery techniques, such as the cyclic steam injection, submits the materials to severe temperature variations, reducing the oil well lifespan; and may lead to failure of the steel casing and cement sheath. The loss of integrity of the cement sheath may lead to leakage of the fluids present in the formation and, in some cases, causing significant environmental and economic damages. In the case of wells subjected to the cyclic steam injection, resistance, flexibility and thermal properties have been identified as the key to the problem. In the present work, thermomechanical analyzes were performed using the finite element method in transient mode. The steel casing, the cement sheath and the formation were modeled using an axisymmetric 2D model with 8-node quadrilateral elements. The mechanical behavior of the cement sheath was analyzed, being three formulations of pastes studied: reference paste and two other paste with latex additives in concentrations of 125 and 250 ml / kg of cement. The influence of the cement sheath thickness and the heating rate were observed as well as six different coefficient values of thermal expansion for cement paste. It was analyzed the temperature gradients of 150 oC, 200 oC, 250 oC, 300 oC and 350 oC, typical temperatures encountered during the steam injection process, as well as between formations with various levels of rigidity. The study revealed that one of the problems of cement sheath integrity due to steam injection is associated with the heating phase of the well and located in the region of the sheath near the formation. It has been found that linking the use of the more flexible and expansive formulation to an extending temperature gradient period application may prevent damage to the cement sheath by avoiding recementing maneuvers. Such a procedure proved to be effective for more rigid rock media as well as for higher target temperatures.