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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

Viruses as a Model System for Studies of Eukaryotic mRNA Processing

Lindberg, Anette January 2003 (has links)
Viruses depend on their hosts for the production and spread of new virus particles. For efficient virus replication, the viral genes have adapted the strategy of being recognized and processed by the cellular biosynthetic machineries. Viruses therefore provide an important tool to study the cellular machinery regulating gene expression. In this thesis, we have used two model DNA viruses; herpes simplex virus (HSV) and adenovirus, to study RNA processing at the level of pre-mRNA splicing in mammalian cells. During a lytic infection, HSV cause an almost complete shut-off of host cell gene expression. Importantly, HSV infection cause inhibition of pre-mRNA splicing which is possibly advantageous to the virus, as only four HSV genes contain introns. The HSV immediate early protein, ICP27, has been shown to modulate several post-transcriptional processes such as polyadenylation and pre-mRNA splicing. We have studied the role of ICP27 as an inhibitor of pre-mRNA splicing. We show that ICP27 inhibits pre-mRNA splicing in vitro in the absence of other HSV proteins. We further show that ICP27 inhibits splicing at the level of spliceosome assembly. Importantly, ICP27 induced inhibition of splicing can be reversed, either by the addition of purified SR proteins or by the addition of an SR protein specific kinase, SRPK1. We propose that SR proteins are prime candidates as mediators of the inhibitory effect of ICP27 on pre-mRNA splicing. In order to learn more about how splicing is organized in the cell nucleus in vivo, we investigated how cellular splicing factors are recruited to sites of transcription and splicing in adenovirus infected cells using confocal microscopy. Our results showed that the SR proteins, ASF/SF2 and SC35, are efficiently recruited to sites in the nucleus where adenovirus genes are transcribed and the resulting pre-mRNAs are processed. Our results demonstrate that only one of the two RNA recognition motifs (RRMs) present in the ASF/SF2 protein is required for its recruitment to active sites of splicing. The arginine/serine rich (RS) domain in ASF/SF2 is redundant and insufficient for the translocation of the protein to active viral polymerase II genes in adenovirus infected cells.
12

Hepatitis Delta Virus: Identification of Host Factors Involved in the Viral Life Cycle, and the Investigation of the Evolutionary Relationship Between HDV and Plant Viroids

Sikora, Dorota 19 June 2012 (has links)
Hepatitis delta virus (HDV) is the smallest known human RNA pathogen. It requires the human hepatitis B virus (HBV) for virion production and transmission, and is hence closely associated with HBV in natural infections. HDV RNA encodes only two viral proteins - the small and the large delta antigens. Due to its limited coding capacity, HDV needs to exploit host factors to ensure its propagation. However, few human proteins are known to interact with the HDV RNA genome. The current study has identified several host proteins interacting with an HDV-derived RNA promoter by multiple approaches: mass spectrometry of a UV-crosslinked ribonucleoprotein complex, RNA affinity chromatography, and screening of a library of purified RNA-binding proteins. Co-immunoprecipitation, both in vitro and ex vivo, confirmed the interactions of eEF1A1, p54nrb, PSF, hnRNP-L, GAPDH and ASF/SF2 with both polarities of the HDV RNA genome. In vitro transcription assays suggested a possible involvement of eEF1A1, GAPDH and PSF in HDV replication. At least three of these proteins, eEF1A1, GAPDH and ASF/SF2, have also been shown to associate with potato spindle tuber viroid (PSTVd) RNA. Because HDV’s structure and mechanism of replication share many similarities with viroids, subviral helper-independent plant pathogens, I transfected human hepatocytes with RNA derived from PSTVd. Here, I show that PSTVd RNA can replicate in human hepatocytes. I further demonstrate that a mutant of HDV, lacking the delta antigen coding region (miniHDV), can also replicate in human cells. However, both PSTVd and miniHDV require the function of the small delta antigen for successful replication. Our discovery that HDV and PSTVd RNAs associate with similar RNA-processing pathways and translation machineries during their replication provides new insight into HDV biology and its evolution.
13

Prestationsmått i arbetsintegrerande sociala företag : en fallstudie av ASF i norra Sverige

Gustafsson, Dennis, Henriksson, Susanne January 2018 (has links)
Sociala företag är en relativt ny företeelse och denna studie riktar in sig specifikt påarbetsintegrerande sociala företag (ASF). ASF karaktäriseras av det sociala målet attsysselsätta människor som står långt från arbetsmarknaden eller har svårt att hittaarbete. Samtidigt är organisationen ett kommersiellt företag med försäljning avprodukter och/eller tjänster vilket innebär att både sociala och ekonomiska prestationerär kärnan i verksamheten. Vinstmaximering är inte ett primärt mål för ASF, men liktandra företag måste intäkterna täcka kostnaderna. Detta innebär att både sociala ochekonomiska mål skall uppnås, vilket kan skapa friktion. Företagets måluppfyllelse kanföljas och kontrolleras genom olika prestationsmått. Syftet med studien är att undersökahur och varför arbetsintegrerande sociala företag använder sig av prestationsmått, settgenom en lins av institutionell logik. Utifrån syftet försöker studien även identifieravilka prestationer som mäts och hur det tar sig uttryck; varför företagen väljer attanvända eller inte använda vissa prestationsmått; samt hur institutionell logik tar siguttryck i finansiella och icke-finansiella prestationsmått. Studien har en kvalitativ ansatsoch ett abduktivt angreppssätt. Empirin insamlas genom semi-strukturerade intervjuer,dokument och observationer. Resultatet av studien visar att ASF utför få formellaprestationsmätningar vilket resulterar i få explicita prestationsmått. Den socialavälfärdslogiken dominerar bland respondenterna vilket färgar ASF:ens arbete genom attfokus riktas mot människor och miljö snarare än effektivitet och ekonomisk vinst. Denkommersiella logiken som återfinns internt, men även hos intressenter, påverkar vilkafinansiella prestationsmått som används av ASF:en genom logikens normer ochvärderingar över vilka ekonomiska prestationer som bör mätas. Den socialavälfärdslogikens inflytande leder till att prestationsmätningen ofta sker muntligt ochostrukturerat, eftersom att stor hänsyn tas till individens situation.
14

Incorpora??o do res?duo oriundo do beneficiamento de caulim em concreto asf?ltico / Incorporation of the residue originating from the improvement of kaolin in asphalt concrete

Costa, Cibele Gouveia 10 November 2006 (has links)
Made available in DSpace on 2014-12-17T15:03:18Z (GMT). No. of bitstreams: 1 CibeleGC.pdf: 1402838 bytes, checksum: db637069ba867fa96c00ae8cf6ff383c (MD5) Previous issue date: 2006-11-10 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The municipal district of Equador-RN is located in an area of great amounts of ores, being your main economical activity the extraction and the kaolin improvement. The main originating from environmental problem that activity is the amount of generated residue, about 70% of the extracted kaolin. The residues are simply piled up in lands of the improvement companies, occupying like this a large area and causing impact in the existent flora. When dry, the residues transform powdered and for the action of the wind, they disperse, polluting the air. Being like this, the present work has as objective evaluates the incorporation of the great residue, originating from of the kaolin improvement, in partial substitution of all the employed aggregates in a conventional mixture of asphalt concrete, which was used in the paving of BR101/RN061 - passage between Ponta Negra and Ares. That evaluation was accomplished in three stages. The first refers to the evaluation of the physical, thermal and mineralogical characteristics of the residue with the intention of to classify it and to define your application as aggregate (small and great). The second refers to the physical characterization of the aggregates and of the asphalt material used in the conventional mixture. And the third, to the evaluation of the mixtures containing residue, which were elaborated starting from the conventional mixture with the gradual incorporation of the residue, from 5 to 40%, in substitution to the part of the conventional aggregates, in way to obtain similar particle size curves the one of the conventional mixture. That evaluation was accomplished through the comparison between the volumetric composition, the mechanical behavior and the susceptibility to the humidity of the mixtures containing residue with the one of the conventional mixture, and with the one of the DNIT specifications. The results show that the great residue originating from of the kaolin improvement has grains of the most varied size, being like this, it can substitute part of all the conventional aggregates and of the filler in an asphalt mixture. Besides, your mineralogical composition presented the same present minerals in the composition of conventional aggregates used in paving. The results evaluation of the volumetric composition of the mixtures containing residue indicates that it can use up to 30% of residue in substitution to the conventional aggregates. The evaluation of the mechanical behavior of those mixtures indicates that the residue increment in the studied mixtures caused an increase of the stability and a reduction of the resistance to the traction. The values obtained in the resistance to the traction meet below the minimum value specified by DNIT, but close to the value obtained in the conventional mixture. When taking in consideration the susceptibility of the same ones to the humidity, the results indicate that she can use up to 25% of residue / O munic?pio de Equador-RN est? localizado numa regi?o de grandes quantidades de min?rios, sendo sua principal atividade econ?mica a extra??o e o beneficiamento de caulim. O principal problema ambiental proveniente dessa atividade ? a quantidade de res?duo gerado, cerca de 70% do caulim extra?do. Os res?duos s?o simplesmente amontoados em terrenos das empresas de beneficiamento, ocupando assim uma grande ?rea e causando impacto na flora existente. Quando secos, os res?duos transformam-se em p? e pela a??o do vento, se espalham, poluindo o ar. Sendo assim, o presente trabalho tem como objetivo avaliar a incorpora??o do res?duo grosso, oriundo do beneficiamento de caulim, em substitui??o parcial de todos os agregados empregados em uma mistura convencional de concreto asf?ltico, a qual foi utilizada na pavimenta??o da BR101/RN061 trecho entre Ponta Negra e Ares. Essa avalia??o foi realizada em tr?s etapas. A primeira refere-se ? avalia??o das caracter?sticas f?sicas, t?rmicas e mineral?gicas do res?duo com o intuito de classific?-lo e definir sua aplica??o como agregado (mi?do e gra?do). A segunda refere-se ? caracteriza??o f?sica dos agregados e do material asf?ltico utilizados na mistura convencional. E a terceira ? avalia??o das misturas contendo res?duo, as quais foram elaboradas a partir da mistura convencional com a incorpora??o gradativa do res?duo, de 5 a 40%, em substitui??o ? parte dos agregados convencionais, de forma a obter curvas granulom?tricas similares a da mistura convencional. Essa avalia??o foi realizada atrav?s da compara??o entre a composi??o volum?trica, o comportamento mec?nico e a suscetibilidade ? umidade das misturas contendo res?duo com os da mistura convencional, e com os das especifica??es exigidas pelo DNIT. Os resultados mostram que o res?duo grosso oriundo do beneficiamento de caulim possui gr?os dos mais variados di?metros, sendo assim, pode substituir parte de todos os agregados convencionais e do filler em uma mistura asf?ltica. Al?m disso, a sua composi??o mineral?gica apresentou os mesmos minerais presentes na composi??o de agregados convencionais utilizados em pavimenta??o. Os resultados da avalia??o da composi??o volum?trica das misturas contendo res?duo indicam que se pode empregar at? 30% de res?duo em substitui??o aos agregados convencionais. A avalia??o do comportamento mec?nico dessas misturas indicam que o incremento de res?duo nas misturas estudadas ocasionou um aumento da estabilidade e uma redu??o da resist?ncia ? tra??o. Os valores obtidos na resist?ncia ? tra??o se encontram abaixo do valor m?nimo especificado pelo DNIT, mas pr?ximos ao valor obtido na mistura convencional. Ao levar em considera??o a suscetibilidade das mesmas ? umidade, os resultados indicam que se pode empregar at? 25% de res?duo
15

Estudo de viabilidade t?cnica do uso de res?duos oriundos do beneficiamento de scheelita na composi??o de concretos asf?lticos / Technical feasibility study of using waste from scheelite processing in composition of asphaltic

Costa Filho, Francisco das Chagas da 03 February 2017 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-03-20T23:06:42Z No. of bitstreams: 1 FranciscoDasChagasDaCostaFilho_DISSERT.pdf: 6168357 bytes, checksum: c578fb868ea385c90fbc6817fbe806b9 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-03-24T21:28:11Z (GMT) No. of bitstreams: 1 FranciscoDasChagasDaCostaFilho_DISSERT.pdf: 6168357 bytes, checksum: c578fb868ea385c90fbc6817fbe806b9 (MD5) / Made available in DSpace on 2017-03-24T21:28:11Z (GMT). No. of bitstreams: 1 FranciscoDasChagasDaCostaFilho_DISSERT.pdf: 6168357 bytes, checksum: c578fb868ea385c90fbc6817fbe806b9 (MD5) Previous issue date: 2017-02-03 / A produ??o mineral brasileira ? uma atividade de suma import?ncia para a economia do pa?s, visto que al?m de contribuir para o produto interno bruto - PIB, ? respons?vel pela gera??o de muitos empregos diretos e indiretos. Neste cen?rio, a minera??o Tomaz Salustino S/A (Mina Breju?) ? uma grande representante nordestina deste setor. Dados de 2012 demonstram que a produ??o da Mina Breju? era em torno de 20 toneladas mensais (MACHADO 2012), representando mais de 300 empregos gerados, al?m do desenvolvimento do munic?pio de Currais Novos, onde a empresa est? situada. Entretanto, devido ao beneficiamento do min?rio (scheelita), desde 1943, foram geradas toneladas de res?duos, e, atualmente, estima-se que no entorno da minera??o existe cerca de 7 milh?es de toneladas (4,5 milh?es de fra??o grossa e 2,5 milh?es de fra??o fina), dispostos em pilhas e bacias de res?duos, gerando diversos impactos ambientais, como a modifica??o da paisagem local. Em vista deste grande estoque de res?duo, aliado a necessidade de extra??o de mat?ria prima natural para compor as camadas usuais de um pavimento, o presente estudo avaliou a viabilidade t?cnica dos res?duos provenientes da Mina Breju? na composi??o de concretos asf?lticos, em substitui??o ao agregado mi?do natural, pela fra??o grossa do res?duo, e, do f?ler convencional, pela fra??o fina do res?duo. Para isto, realizaram-se ensaios de caracteriza??o f?sica, qu?mica e mineral?gica das fra??es do res?duo e dos agregados naturais utilizados na pesquisa, al?m de dosagens Marshall em composi??es de concretos asf?lticos para analisar os par?metros volum?tricos e a estabilidade dos materiais quanto a utiliza??o em obras vi?rias. A partir do programa experimental proposto, pode-se verificar que a fra??o grossa do res?duo do beneficiamento da scheelita apresentou um potencial elevado para ser utilizado in natura como agregado mi?do, pois os corpos de prova analisados demonstraram bom desempenho com rela??o aos par?metros volum?tricos e a estabilidade Marshall. A fra??o fina tamb?m se mostrou vi?vel para ser utilizada como f?ler artificial, por?m, para tal aplica??o, se faz necess?rio processos de melhoramento de qualidade para que a fra??o do res?duo se enquadre como material de enchimento de misturas asf?lticas, visto que in natura, a mesma n?o apresentou os 65% de material passante na peneira de 0,075 mm requisitado pela norma DNER - EM 367/97 (DNER, 1997a). / The Brazilian mineral production is an extremely important activity for the country's economy, since in addition to contributing to gross national product - PIB, it is responsible for the generation of many direct and indirect jobs. Therefore, the Tomaz Salustino Corporation Mining (Breju? Mine) is a important northeastern representative of this sector. Data for 2012 show that the production of the Breju? Mine was around 20 tons per month (MACHADO 2012), representing more than 300 jobs generated, in addition to the development of the municipality of Currais Novos. However, due to the ore (scheelite) processing, since 1943, tons of waste have been generated, and it is currently estimated around 7 million tons (4.5 million thick fractions and 2.5 million fine fractions), disposed in piles and waste basins, generating several environmental impacts, such as the modification of the local landscape. Due of this large stock of waste, jointly with the need for extraction of natural raw material to compose the usual layers of a pavement, the present study evaluated the technical feasibility of the residues from the Breju? Mine in the composition of asphaltic concretes, replacing the natural small aggregate by the thick fractions of the residue, and the conventional filler by the fine fractions of the residue. For this, chemical and mineralogical characterization of fractions of the residue and of the natural aggregates used in the research, besides Marshall dosages in compositions of asphaltic concretes was carried out to analyze the volumetric parameters and the stability of the materials as for the use in road works. From the proposed experimental program, it can be verified that the thick fractions of the scheelite processing residue presented a high potential to be used in natura as a small aggregate, because the analyzed specimens showed good performance in relation to the volumetric parameters and the Marshall stability. The fine fraction has also proved feasible to be used as an artificial filler, however, for this application, it is necessary to improve the quality for that the fraction of the residue fits as asphalt mixtures filling material since, in natura, it did not present the 65% passing material in the 0.075 mm sieve required by DNER - EM 367/97 (DNER, 1997a).
16

Hepatitis Delta Virus: Identification of Host Factors Involved in the Viral Life Cycle, and the Investigation of the Evolutionary Relationship Between HDV and Plant Viroids

Sikora, Dorota January 2012 (has links)
Hepatitis delta virus (HDV) is the smallest known human RNA pathogen. It requires the human hepatitis B virus (HBV) for virion production and transmission, and is hence closely associated with HBV in natural infections. HDV RNA encodes only two viral proteins - the small and the large delta antigens. Due to its limited coding capacity, HDV needs to exploit host factors to ensure its propagation. However, few human proteins are known to interact with the HDV RNA genome. The current study has identified several host proteins interacting with an HDV-derived RNA promoter by multiple approaches: mass spectrometry of a UV-crosslinked ribonucleoprotein complex, RNA affinity chromatography, and screening of a library of purified RNA-binding proteins. Co-immunoprecipitation, both in vitro and ex vivo, confirmed the interactions of eEF1A1, p54nrb, PSF, hnRNP-L, GAPDH and ASF/SF2 with both polarities of the HDV RNA genome. In vitro transcription assays suggested a possible involvement of eEF1A1, GAPDH and PSF in HDV replication. At least three of these proteins, eEF1A1, GAPDH and ASF/SF2, have also been shown to associate with potato spindle tuber viroid (PSTVd) RNA. Because HDV’s structure and mechanism of replication share many similarities with viroids, subviral helper-independent plant pathogens, I transfected human hepatocytes with RNA derived from PSTVd. Here, I show that PSTVd RNA can replicate in human hepatocytes. I further demonstrate that a mutant of HDV, lacking the delta antigen coding region (miniHDV), can also replicate in human cells. However, both PSTVd and miniHDV require the function of the small delta antigen for successful replication. Our discovery that HDV and PSTVd RNAs associate with similar RNA-processing pathways and translation machineries during their replication provides new insight into HDV biology and its evolution.
17

Disruption of D-cyclin transcriptional regulation of the Androgen Receptor: Mechanism and Consequence

Olshavsky, Nicholas 05 August 2010 (has links)
No description available.
18

Regulation and Functional Impact of Opioid Receptor Splicing in Response to Morphine

Regan, Patrick M. January 2015 (has links)
Multiple classes of pharmaceuticals, including acetaminophen, aspirin, and other nonsteroidal anti-inflammatory drugs (NSAIDs), are used to relieve mild to moderate pain; however, one of the oldest classes of pharmaceuticals, opioids, remains the primary class of drugs used in the management of severe pain. For decades, the unique pharmacological profiles of opioid compounds have suggested the existence of multiple opioid receptor subtypes and, accordingly, four opioid receptors have been cloned to date; the mu (μ)-opioid receptor, the kappa (κ)-opioid receptor, the delta (δ)-opioid receptor, and the nociceptin/orphanin FQ receptor. Additionally, each receptor is encoded by its own distinct gene; the OPRM1, OPRK1, OPRD1, and OPRL1, respectively. Despite the identification and characterization of these four opioid receptor subtypes, pharmacological data, particularly from opioid receptor knockout mice, does not conform to the predications of a four opioid receptor model and instead suggests the existence of additional receptor subtypes. Additional opioid receptors have since been proposed but corresponding genes have either been unidentified or found to be genetically unrelated. Interestingly, this problem is not unique to opioid receptors, as there is a large discrepancy between the number of protein encoding genes and the repertoire of mRNA transcripts and encoded proteins they produce, with gene products far more numerous than estimates would predict. It is now understood that this discrepancy is due to the generation of multiple RNA transcripts from a single gene. Several mechanisms are utilized in order to generate mRNA transcript variants, or isoforms, from a single gene; however, the primary mechanism, known as alternative splicing, involves a complex macromolecular machine, referred to as the spliceosome, through which specific portions of the precursor mRNA (pre-mRNA) sequence are selectively removed and the remaining nucleotide sequences are ligated to form a unique mRNA transcript. Recently, multiple opioid receptor isoforms, particularly for the μ-opioid receptor, have been identified; however, both their regulation and their functional significance are poorly characterized. As such, multiple studies are needed to more precisely describe alternatively spliced μ-opioid receptor isoforms, particularly the regulation of spliceosome components that determine the splicing specificity of particular isoforms as well as the distinct signaling pathways utilized by particular isoforms both constitutively and following agonist binding. Using a model of dopaminergic neurons, this study sought to examine these questions and found that expression of a particular splice variant, MOR-1X, was up-regulated by morphine through a mechanism involving the essential splicing factor ASF/SF2. Structural comparison of this isoform to the prototypical variant MOR-1 found that the unique distal portion of C-terminal domain contains two additional PKA phosphorylation sites as well as a second agonist-induced phosphorylation motif highly conserved among opioid receptors. Functional comparison of MOR-1 and MOR-1X found distinct signaling differences, both constitutively and following morphine treatment, in MAPK signaling cascades, particularly ERK1/2. While the pharmacological significance of MOR-1X expression and signaling remains unclear, the clinical importance of this finding extends beyond a mechanism of opioid analgesic variability, as the physiological roles of opioids also include immunomodulation and have been implicated specifically in the exacerbation of HIV viral replication and pathology, particularly neurocognitive dysfunction. Accordingly, the HIV viral protein Tat was found to block morphine-mediated increases in MOR-1X expression by similarly blocking morphine-mediated increases in ASF/SF2 expression. Consequently, MOR-1X and HIV viral proteins were found to have a unique and synergistic role in the regulation of intrinsic apoptotic signaling cascades, specifically Bax expression, and in cell proliferation. Therefore, the regulation of alternative splicing events by both opioids and HIV viral proteins involves, in part, the inverse regulation of ASF/SF2 protein expression, through which the expression of the MOR-1X isoform is subsequently and significantly altered. This, in turn, may lead to functional consequences in opioid pharmacokinetics as well as in opioid-related pathology, such as the exacerbation of HIV associated neurocognitive dysfunction, as MOR-1X contains unique functional regions which may be responsible for the observed differences in MAPK and intrinsic apoptotic signaling and cellular proliferation. Collectively, these findings support previous studies that suggest alternative splicing of the MOR is altered by exogenous factors, such as morphine and HIV, identify unique signaling pathways for various opioid receptor isoforms, and are the first to suggest a potential mechanism through which pharmacological interventions could be utilized to alter opioid receptor isoform expression, thereby altering the pharmacological and physiological effects of opioids. / Biomedical Neuroscience
19

Gera??o autom?tica de testes a partir de descri??es de linguagens

Antunes, Cleverton Hentz 01 March 2010 (has links)
Made available in DSpace on 2014-12-17T15:47:51Z (GMT). No. of bitstreams: 1 ClevertonHA.pdf: 1775580 bytes, checksum: 9e49f67c9b7fbb459e2b24f568db691b (MD5) Previous issue date: 2010-03-01 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Some programs may have their entry data specified by formalized context-free grammars. This formalization facilitates the use of tools in the systematization and the rise of the quality of their test process. This category of programs, compilers have been the first to use this kind of tool for the automation of their tests. In this work we present an approach for definition of tests from the formal description of the entries of the program. The generation of the sentences is performed by taking into account syntactic aspects defined by the specification of the entries, the grammar. For optimization, their coverage criteria are used to limit the quantity of tests without diminishing their quality. Our approach uses these criteria to drive generation to produce sentences that satisfy a specific coverage criterion. The approach presented is based on the use of Lua language, relying heavily on its resources of coroutines and dynamic construction of functions. With these resources, we propose a simple and compact implementation that can be optimized and controlled in different ways, in order to seek satisfaction the different implemented coverage criteria. To make the use of our tool simpler, the EBNF notation for the specification of the entries was adopted. Its parser was specified in the tool Meta-Environment for rapid prototyping / Alguns programas podem ter sua entrada formalizada atrav?s de gram?ticas livres de contexto. Esta formaliza??o facilita a utiliza??o de ferramentas na sistematiza??o e na eleva??o da qualidade do seu processo de teste. Dentro desta categoria de programas os compiladores foram os primeiros a utilizar este tipo de ferramenta para a automa??o de seus testes. Neste trabalho apresentamos uma abordagem para a defini??o de testes a partir da descri??o formal das entradas do programa. A gera??o das senten?as ? realizada levando em considera??o aspectos sint?ticos definidos pela especifica??o da entrada, a gram?tica. Por quest?es de otimiza??o s?o utilizados crit?rios de cobertura para limitar a quantidade de testes sem diminuir a sua qualidade. Nossa abordagem utiliza estes crit?rios no direcionamento da gera??o de maneira a produzir senten?as que satisfa?am um crit?rio de cobertura especifico. A abordagem apresentada se baseia na utiliza??o da linguagem Lua, se apoiando fortemente em seus recursos de corotinas e constru??o din?mica de fun??es. Com estes recursos, propomos uma implementa??o compacta e simples que pode ser otimizada e controlada de formas variadas, com o intuito de buscar a satisfa??o dos diferentes crit?rios de cobertura implementados. Para tornar simples o uso de nossa ferramenta foi adotada a nota??o EBNF para a especifica??o das entradas. O seu parser foi especificado na ferramenta Meta-Environment por esta favorecer a r?pida prototipa??o
20

Obten??o de emuls?es asf?lticas modificadas utilizando res?duos industriais

Lima, Cristian Kelly Morais de 03 August 2012 (has links)
Made available in DSpace on 2014-12-17T15:01:55Z (GMT). No. of bitstreams: 1 CristianKML_TESE.pdf: 2781872 bytes, checksum: b802df1c9b2c68b6ef21241e1bb5281e (MD5) Previous issue date: 2012-08-03 / The main objective of this research was the development and characterization of conventional and modified cationic asphalt emulsions. The asphalt emulsions were developed by using the Petroleum Asphalt Cement (CAP 50-70) from Fazenda Bel?m (Petrobras -Aracati-Ce). The first step in this research was the development of the oil phase (asphalt + solvent) and the aqueous phase (water + emulsifying agent + acid + additives), separately. During the experiments for the obtaining of the conventional asphalt emulsion, the concentration of each constituent was evaluated. For the obtaining of the oil phase, kerosene was used as solvent at 15 and 20 wt.%. For the development of the aqueous phase, the emulsifying agent was used at 0.3 and 3.0 wt.%, whereas the acid and the additive were set at 0.3 wt.%. The percentage of asphalt in the asphalt emulsion was varied in 50, 55, and 60 wt.% and the heating temperature was set at 120 ?C. The aqueous phase in the asphalt emulsion was varied from 16.4 to 34.1 wt.% and the heating temperature was set at 60 ?C. After the obtaining of the oil and the aqueous phases, they were added at a colloidal mill, remaining under constant stirring and heating during 15 minutes. Each asphalt emulsion was evaluated considering: sieve analysis, Saybolt Furol viscosity, pH determination, settlement and storage stability, residue by evaporation, and penetration of residue. After the characterization of conventional emulsions, it was chosen the one that presented all properties in accordance with Brazilian specifications (DNER-EM 369/97). This emulsion was used for the development of all modified asphalt emulsions. Three polymeric industrial residues were used as modifier agents: one from a clothing button industry (cutouts of clothing buttons) and two from a footwear industry (cutouts of sandals and tennis shoes soles), all industries located at Rio Grande do Norte State (Brazil).The polymeric residues were added into the asphalt emulsion (1 to 6 wt.%) and the same characterization rehearsals were accomplished. After characterization, it were developed the cold-mix asphalts. It was used the Marshall mix design. For cold-mix asphalt using the conventional emulsion, it was used 5, 6 and 7 wt.% asphalt emulsion. The conventional mixtures presented stability values according Brazilian specification (DNER-369/97). For mixtures containing asphalt modified emulsions, it was observed that the best results were obtained with emulsions modified by button residue / Neste trabalho desenvolveu-se e caracterizou-se emuls?es asf?lticas cati?nicas convencionais e modificadas. As emuls?es asf?lticas convencionais foram obtidas utilizandose como mat?ria-prima o Cimento Asf?ltico de Petr?leo (CAP 50-70), oriundo da Fazenda Bel?m (PETROBRAS-Aracati-CE), cedido pela LUBNOR-Lubrificantes e Derivados de Petr?leo do Nordeste (Fortaleza-CE). A pesquisa foi iniciada com o desenvolvimento da fase ?leo (asfalto + solvente) e da fase aquosa (?gua + emulsificante + ?cido + aditivo), separadamente. Para a obten??o da emuls?o asf?ltica convencional, a concentra??o de cada constituinte foi avaliada. Para a fase ?leo, o asfalto foi utilizado nas concentra??es de 50, 55 e 60 %, e o solvente (querosene) nas concentra??es de 15 e 20 %. A temperatura de aquecimento desta fase foi de 120 ?C. Para o desenvolvimento da fase aquosa, o emulsificante foi utilizado nas concentra??es de 0,3 e 3,0 %, enquanto que o ?cido e o aditivo foram utilizados apenas na concentra??o de 0,3 %. A concentra??o de ?gua variou de 16,4 a 34,1 % e a temperatura de aquecimento da fase aquosa foi de 60 ?C. Ap?s o preparo de ambas as fases, estas foram introduzidas no moinho coloidal, onde permaneceram em aquecimento e em sistema de refluxo, durante 15 minutos. Ap?s a obten??o de cada emuls?o asf?ltica, foram feitos os seguintes ensaios de caracteriza??o: peneiramento, viscosidade Saybolt Furol, pH, sedimenta??o, adesividade, res?duo por evapora??o e penetra??o. Ap?s a caracteriza??o das emuls?es asf?lticas convencionais, escolheu-se a emuls?o que apresentou resultados de acordo com a especifica??o (DNER-EM 369/97) para, em seguida, desenvolver as emuls?es asf?lticas modificadas. As emuls?es asf?lticas foram modificadas atrav?s da adi??o de res?duos polim?ricos provenientes da ind?stria de bot?es e de cal?ados (sand?lia e t?nis), localizadas no Rio Grande do Norte. Os res?duos polim?ricos foram adicionados na emuls?o asf?ltica de 1 a 6 %. Ap?s a obten??o das emuls?es asf?lticas modificadas foram feitos os ensaios de caracteriza??o. Conclu?da tais etapas, continuou-se a pesquisa com o desenvolvimento de misturas asf?lticas a frio. O m?todo Marshall foi utilizado como m?todo de dosagem destas misturas. De acordo com os resultados obtidos, conclui-se que foi poss?vel determinar uma composi??o de emuls?o asf?ltica convencional que atendesse a alguns requisitos presentes na especifica??o (DNER-EM 369/97). Quanto ?s misturas asf?lticas a frio, utilizando as emuls?es convencionais, conclui-se que, para os teores de emuls?o utilizados (5, 6 e 7 %), estas apresentaram valores de estabilidade acima do recomendado na especifica??o. Para as misturas asf?lticas a frio, que utilizaram as emuls?es modificadas, os melhores resultados de estabilidade foram obtidos com a emuls?o modificada com res?duo de bot?o

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