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Análise da inserção da mineração em pequena escala no planejamento urbano em quatro regiões metropolitanas no estado de São Paulo. / Analysis of incorporating small-scale mining in urban planning in four metropolitan regions in the state of São Paulo.Araujo, Carlos Henrique Xavier 03 April 2018 (has links)
O estado de São Paulo é o maior consumidor de agregados minerais do Brasil e está entre os maiores produtores destes bens minerais com uma produção voltada principalmente para construção civil, indústria e agricultura. Tendo-se em vista a relevância da mineração, o presente trabalho tem como objetivo caracterizar como a mineração de pequeno porte de areia e brita tem participado no planejamento urbano em regiões metropolitanas, utilizando como exemplo quatro regiões metropolitanas no estado de São Paulo e o Plano de Desenvolvimento Urbano Integrado (PDUI) de cada uma delas. Neste trabalho foi desenvolvido uma metodologia de análise a partir da consulta a fontes de dados primários e secundários. Os dados primários são do setor mineral do estado de São Paulo que engloba a micro, pequena e média mineração, de 2010 a 2014. Os dados secundários foram obtidos a partir de estudos referentes ao mercado produtor e consumidor das substâncias minerais escolhidas para esta pesquisa. Foi realizado também uma análise de como é a gestão de agregados e políticas públicas na Província de Ontário no Canadá. Como o estudo foi focado no estado de São Paulo, cada um dos PDUIs foi analisado e o resultado é que há pouca interação com a setor mineral e que para a mineração no estado de São Paulo ser exemplo de responsabilidade ambiental, social, econômica é necessário transparência e informação sobre a atividade, além da integração dos atores relevantes. / The state of São Paulo is the largest consumer of mineral aggregates in Brazil and one of the largest producers of mineral goods with a production focused mainly on civil construction, agriculture and industry. Taking into account the relevance of mining, the present study aims to characterize how sand and gravel small-scale mining has been contributing to urban planning in metropolitan regions, taking as example, four metropolitan regions in the state of São Paulo and their Integrated Urban Development Plans (IUDP). In this work, an analysis methodology was developed based on the investigation of primary and secondary data sources. The primary data is from the mineral sector of the state of São Paulo, which covers micro, small and medium-mining from 2010 to 2014. Secondary data was obtained from studies concerning the producer and consumer market of the mineral substances chosen for this research. In addition, an analysis regarding aggregate management and public policies was conducted in the Province of Ontario in Canada. Since the study was focused on the state of São Paulo, each of the IUDPs was analyzed and the result is that there is little interaction with the mineral sector and that for mining in the state of São Paulo to be an example of environmental, social and economic responsibility, transparency and information on the activity is necessary, as well as the integration of the relevant actors.
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Immunhistochemische Vergleichsanalyse von Primärzellaggregaten und Ursprungsgeweben unterschiedlicher Dignität zur Charakterisirung der in-vitro AnpassungString, Andreas Sebastian 19 April 2002 (has links)
Immunhistochemische Vergleichsanalyse von Primärzellaggregaten und Ursprungsgeweben unterschiedlicher Dignität zur Charakterisierung der in-vitro Anpassung Zielsetzung: Dreidimensionale Zellkulturen stellen eine Weiterentwicklung der einschichtigen Zellkultur dar, die den in-vitro Bedingungen im Organismus näherkommt. Darüber hinaus ermöglichen organoide Kulturen, die neben der vorherrschenden Tumorzelle auch Bindegewebszellen und Immunzellen enthalten, eine Analyse der Interaktion dieser Zellen bei wichtigen Aspekten der Krebserkrankung wie Metastasierung, Angiogenese oder der Tumorimmunologie. Materialien und Methoden: Operationsresektate von Schilddrüsengeweben, -adenomen und -karzinomen, Ovarialkarzinomen und Sarkomen wurden in Einzelzellsuspensionen überführt. Nach Inkubation im Schüttler wurden innerhalb von 24-48 Stunden Primärzellaggregate gezüchtet, von denen Kryostatschnitte angefertigt wurden. Mit der APAAP-Methode wurden Epithelzell-, Leukozyten-, Makrophagen- und Endothelzellmarker sowie E-Cadherin, die a2-, a4-, a5- und av Integrinkette, IGF-I und EGF Rezeptoren, cerbB2 sowie Cathepsin D immunhistochemisch untersucht. Die Färbungen der Aggregate und der Herkunftsgewebe wurden statistisch mit dem Mann-Whitney Test verglichen. Ergebnisse: Primäraggregate konnten zu 90-100% aus Operationsresektaten kultiviert werden. Epithelzellen, Leukozyten, Makrophagen und Endothelzellen waren im Primäraggregaten und den Herkunftsgeweben ungefähr gleichmäßig vorhanden. Dies gilt auch für E-Cadherin, a4-Integrin, IGF-I und EGF Rezeptoren, cerbB2 und Cathepsin D. Die a2-, a5- und av Integrinkette trat nur in den Primäraggregaten von Schilddrüsengeweben und -adenomen nicht aber in deren Herkunftsgeweben auf, was auf eine de-novo Exprimierung schließen läßt. Schlußfolgerung: Mit der verwendeten Methode ist es relativ einfach möglich, organoide Primäraggregate zu züchten, die ein geeignetes Forschungsobjekt für verschiedene Aspekte der Tumorpathologie darstellen. Die gefundenen Unterschiede der Integrinexpression zeigen eine Anpassung and die in-vitro Kultivierung und sind möglicherweise eine Reaktion zur Vermeidung der matrix-abhängigen Apoptose. / Immunohistochemical Analysis of primary cell aggregates and their origin tissue of different pathology to evaluate adaptation to in-vitro environment Objective: Three-dimensional cell cultures reflect more closely the in-vitro environment then monolayer cultures. Furthermore, organoid cultures, which contain beside the dominant tumor cell also mesenchymal cells and leucocytes are used to study the interaction of these cells in several aspects of the tumor pathology, such as metastasis, angiogenesis and tumor immunology. Materials and Methods: Specimens obtained from thyroid tissue, thyroid adenomas and carcinomas, ovarian cancer and sarcomas were dissolved to single cell suspensions. After incubation under stirring, primary cell aggregates were cultured within 24-48 hours. Cryostat sections were made and stained with markers of epithelial cells, leucocytes, macrophages, endothelial cells as well as E-cadherin, a2-, a4-, a5- und av Integrin chain, IGF-I und EGF receptor, cerbB2 and Cathepsin D using the APAAP method. The immunhistochemical results of the aggregates and their origin tissue were statistically compared using the Mann-Whitney test. Results: Primary cell aggregates could be obtained from up to 90-100% of all probes. Epithelial cells, leucocytes, macrophages and endothelial cells were found equally in aggregates and their origin tissue. Also E-Cadherin, a4-Integrin, IGF-I und EGF receptors, cerbB2 und Cathepsin D were found equally. The a2-, a5- und av integrin chain was expressed in aggregates of thyroid tissue and adenomas, but not in their origin tissue suggesting a de-novo expression. Conclusion: Primary cell aggregates were easily obtained with the used method and could be used as a model in the study of tumor pathology. The different expressions of integrins show an adaptation to the in-vitro environment and could be a reaction to avoid matrix-related apoptosis.
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Screening of Microorganisms, Calcium Sources, and Protective Materials for Self-healing ConcreteChen Hsuan Chiu (5930972) 11 June 2019 (has links)
<p>To make bacterial-based self-healing concrete, alkaline-resistant bacterial spores, nutrient sources, and a calcium source are incorporated into a concrete matrix. Two ureolytic spore-forming bacteria, <i>Sporosarcina pasteurii</i>, <i>Lysinibacillus sphaericus</i>, and two non-ureolytic spore-forming bacteria, <i>Bacillus cohnii</i>, and <i>Bacillus pseudofirmus</i>, which have been used in previous studies as bacterial concrete healing agents, were compared in this study. The four bacteria were compared for their (1) sporulation rates on different sporulation agar plates, (2) growth in five liquid media, (3) survival rates in light weight aggregates (LWA) and in mortar samples, and (4) calcium carbonate precipitation rates from either calcium lactate or calcium nitrate. Sporulation was successfully induced after three-day incubation at 30°C on an appropriate sporulation medium. High sporulation rates of <i>B. cohnii</i>, and <i>B. pseudofirmus</i>(93% and 99% respectively) were found on alkaline R2A medium (AR2A). A sporulation rate (89%) of <i>S. pasteruii</i>was observed on tryptic soy agar supplemented with 2% urea (TSAU)<i>.</i>The highest sporulation rate (60%) of <i>L. sphaericus</i>was found on R2A medium supplemented with 2% urea (R2AU). In the growth study, tryptic soy broth supplemented with 2% urea (TSBU) was a positive control which supported rapid growth of all four bacteria. <i>Sporosarcina pasteurii </i>and <i>L. pasteurii</i>showed rapid growth rates in alkaline yeast extract broth (AYE) and yeast extract with 2% urea broth (YEU) respectively. In contrast, <i>B. cohnii</i>, and <i>B. pseudofirmus</i>grew poorly in all media except in the positive control. Viable counts of the four bacterial spores reduced (1.8–3.3 logs) during the first 24 h in mortar samples and then remained stable for next 27 days testing period. Among the four, <i>S. pasteurii</i>showed the smallest reduction of viable counts (1.8–2.5 logs) in mortar after one day of incubation. Both <i>S. pasteurii</i>and <i>L. sphaericus</i>showed high CaCO<sub>3 </sub>productions (>80%) after 24 h incubation at 30°C in YEU containing either calcium nitrate or calcium lactate. However, <i>B. pseudofirmus</i>and <i>B. cohnii </i>showed<i></i>low calcite recovery rates (<11%) in AYE containing either<i></i>calcium nitrate or calcium lactate under the same incubation condition. Overall, <i>S. pasteurii</i>was the best bacterial concrete healing agent of the four. This bacterium had (1) rapid growth rate in AYE, (2) about 90% sporulation rate within 3 days, (3) highest survival rates after 24 h in mortar samples and, (4) high CaCO<sub>3 </sub>precipitation rates, 82 or 98%, in broth containing calcium nitrate or calcium lactate respectively.</p><p>In addition, two different lightweight aggregates (LWA), expanded shale (ES) and expanded clay (EC), which were used as bacterial carriers and protective materials, were compared in this study. Each type of LWA was separated into three sizes (<0.85 mm, 0.85– 2.0 mm, and >2.0 mm) and immobilized with spores of <i>B. cohnii</i>or <i>B. pseudofirmus.</i>Viable counts recovered from EC and ES reduced <1.0 log after the immobilization process and remained stable during the 150 days testing period. Neither the type nor the particle sizes of the two LWA significantly affected the survival rates of the bacterial spores. This result showed that both EC and ES could be used as carriers for bacterial healing agents. It was also found that when the spores were immobilized with nutrients in LWA, their survival rates in mortar samples can be improved slightly (<1.0 log).</p><p><br></p>
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Durability of a recycled aggregate concrete base course material under coupled environmental exposure and cyclicUnknown Date (has links)
Long term durability is a major concern for wide-scale use of recycled
aggregate materials in civil engineering construction. The purpose of this study is
to provide an insight into the damaging effects of combined wet-dry cycles and
repeated mechanical loading in a recycled aggregate concrete (RAC) base
course material made from recycled crushed concrete aggregate and cement. A
coordinated experimental program followed by a mechanistic pavement modeling
and life cycle analysis was conducted as part of this research study. This
laboratory investigation was divided into three phases each consisting of both
wet-dry exposed specimens (WD), and control or non wet-dry exposed
specimens (NWD). Phase I experiments involved monotonic loading tests under
compression and flexure to evaluate the strength properties. Phase II involved
testing a total of 108 cylindrical specimens in cyclic compressive loading at three different stress ratios. After each regime of cyclic loading, residual compressive
strengths were determined. In addition, the load-deformation hysteresis loops
and the accumulated plastic deformation were continuously monitored through all
loading cycles. Phase III included a flexural fatigue test program on 39 beam
specimens, and fracture testing program on 6 notched beam specimens, each
one having 19-mm initial notch. Traditional SR-N curves, relating the Stress Ratio
(SR) with the number of cycles to failure (N or Nf), were developed. Fatigue crack
growth rate and changes in Stress Intensity Factors were obtained to determine
Paris Law constants and fracture toughness. A mechanistic analysis of a typical
highway pavement incorporating RAC base was performed with KENPAVE
program, followed by a Life Cycle Analysis (LCA) using the GaBi software. It was
found that the specimens subjected to wet-dry cycles suffered significantly higher
damage expressed in terms of accumulated plastic deformation, and loss of
residual compressive strength, modulus, fatigue endurance limit, and design life,
compared to specimens not exposed to wet-dry cycles. Although such
degradation in material properties are important considerations in pavement
design, a concurrent Life Cycle Analysis demonstrated that recycled aggregate
concrete base course still holds promise as an alternative construction material
from environmental stand point. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection
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Iron and steel slag valorization through carbonation and supplementary processesGeorgakopoulos, Evangelos D. January 2016 (has links)
Alkaline industrial wastes are considered potential resources for the mitigation of CO2 emissions by simultaneously capturing and sequestering CO2 through mineralization. Mineralization safely and permanently stores CO2 through its reaction with alkaline earth metals. Apart from natural formations, these elements can also be found in a variety of abundantly available industrial wastes that have high reactivity with CO2, and that are generated close to the emission point-sources. Apparently, it is the applicability and marketability of the carbonated products that define to a great extent the efficiency and viability of the particular process as a point source CO2 mitigation measure. This project investigates the valorization of iron- and steel-making slags through methods incorporating the carbonation of the material, in order to achieve the sequestration of sufficient amounts of CO2 in parallel with the formation of valuable and marketable products. Iron- and steel-manufacturing slags were selected as the most suitable industrial byproducts for the purposes of this research, due to their high production amounts and notable carbonation capacities. The same criteria (production amount and carbonation capacity) were also used for the selection of the iron- and steel-making slag types that are more suitable to the scope of this work. Specifically for the determination of the slag types with the most promising carbonation capacities, the maximum carbonation conversions resulting from recent publications related to the influence of process parameters on the conversion extent of iron- and steel-manufacturing slags, were directly compared to each other using a new index, the Carbonation Weathering Rate, which normalizes the results based on particle size and reaction duration. Among the several iron- and steel-manufacturing slags, basic oxygen furnace (BOF) and blast furnace (BF) slags were found to combine both high production volumes and significant affinity to carbonation. In the context of this research, two different procedures aiming to the formation of value added materials with satisfactory CO2 uptakes were investigated as potential BF and BOF slags valorization methods. In them, carbonation was combined either with granulation and alkali activation (BOF slag), or with hydrothermal conversion (BF slag). Both treatments seemed to be effective and returned encouraging results by managing to store sufficient amounts of CO2 and generating materials with promising qualities. In particular, the performance of the granulation-carbonation of BOF slag as a method leading to the production of secondary aggregates and the sequestration of notable amounts of CO2 in a solid and stable form, was evaluated in this work. For comparison purposes, the material was also subjected to single granulation tests under ambient conditions. In an effort to improve the mechanical properties of the finally synthesized products, apart from water, a mixture of sodium hydroxide and sodium silicate was also tested as a binding agent in both of the employed processes. According to the results, the granules produced after the alkali activation of the material were characterized by remarkably greater particle sizes (from 1 to 5 mm) compared to that of the as received material (0.2 mm), and by enhanced mechanical properties, which in some cases appeared to be adequate for their use as aggregates in construction applications. The maximum CO2 uptake was 40 g CO2/kg of slag and it was achieved after 60 minutes of the combined treatment of alkali activated BOF slag. Regarding the environmental behavior of the synthesized granules, increased levels of Cr and V leaching were noticed from the granules generated by the combination of granulation-carbonation with alkali activation. Nevertheless, the combination of granulation with alkali activation or that of granulation with carbonation were found not to worsen, if not to improve, the leaching behaviour of the granules with regards to the untreated BOF slag. The formation of a zeolitic material with notable heavy metal adsorption capacity, through the hydrothermal conversion of the solid residues resulting from the calcium- extraction stage of the indirect carbonation of BF slag, was also investigated in this project. To this end, calcium was selectively extracted from the slag by leaching, using acetic acid of specific concentration (2 M) as the extraction agent. The residual solids resulting from the filtration of the generated slurry were subsequently subjected to hydrothermal conversion in caustic solution of two different compositions (NaOH of 0.5 M and 2 M). Due to the presence of calcium acetate in the composition of the solid residues, as a result of their inadequate washing, only the hydrothermal conversion attempted using the sodium hydroxide solution of higher concentration (2 M) managed to turn the amorphous slag into a crystalline material, mainly composed by a zeolitic mineral phase (detected by XRD), namely, analcime (NaAlSi2O6·H2O), and tobermorite (Ca5(OH)2Si6O16·4H2O). Finally, the heavy metal adsorption capacity of the particular material was assessed using Ni2+ as the metal for investigation. Three different adsorption models were used for the characterization of the adsorption process, namely Langmuir, Freundlich and Temkin models. Langmuir and Temkin isotherms were found to better describe the process, compared to Freundlich model. Based on the ability of the particular material to adsorb Ni2+ as reported from batch adsorption experiments and ICP-OES analysis, and the maximum monolayer adsorption capacity (Q0 = 11.51 mg/g) as determined by the Langmuir model, the finally synthesized product can potentially be used in wastewater treatment or environmental remediation applications.
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Novos materiais funcionais organo-híbridos baseados em óxidos metálicos e diimidas aromáticas / New hybrid functional materials based in metal oxides and aromatic diimidesChagas-Silva, Fatima Aparecida das 18 May 2012 (has links)
O uso e estudo de materiais híbridos para desenvolver novos materiais com qualidades superiores para aplicações em fotônica, sensores e áreas afins é um desafio para o químico. Neste contexto deve-se especular sobre as propriedades de associação de materiais orgânicos e inorgânicos para alcançar novas e melhores propriedades. Neste estudo, os óxidos metálicos (óxidos de cério em particular), uma classe especial entre nanopartículas inorgânicas, foram selecionados para explorar as suas aplicações com uma classe, também especial de compostos orgânicos, sendo no nosso estudo as Naftaleno Diimidas. Óxido de cério é um semicondutor, com uma “bandgap” larga, conhecido por sua capacidade catalítica e por sua simples manipulação para preparar filmes finos e nanopartículas. Derivados de Naftaleno Diimidas são conhecidos por sua superior atividade eletroquímica comparáveis aos dos Paraquat (metilviologênio), mas com amplitude maior de aplicações fotoquímicas. Foram sintetizadas Naftaleno Diimidas carregados positivamente e negativamente com propriedades surfactantes. Após a caracterização detalhada das Naftaleno Diimidas, incluindo auto-associação e interação com moléculas de surfactantes, a interação com nanopartículas de óxido de cério foram determinadas. As Naftaleno Diimidas interagiram de forma especial com nanopartículas de óxido de cério conferindo ausência de atividade hidrolítica e um comportamento fotocrômico singular. Propõe-se que o corante orgânico se adsorve nas ranhuras das nanopartículas e, além disso forma dímeros estáveis que têm importância para as novas fotoatividades observadas. / The use and study of hybrid materials is a challenge for the chemist to develop materials having new and superior qualities for applications in photonics, sensors and related areas. In this context one has to speculate on the properties of the organic and inorganic partners to achieve better and new properties. In this study the metal oxides (in particular Cerium Oxides), a special class among inorganic nanoparticles were selected to exploit their applications with an also special class of organic compounds the Naphthalene Diimides. Cerium Oxide is a wide bandgap semiconductor well known for its catalytic capabilities and for its simple manipulation to prepare thin films and nanoparticles. Naphthalene Diimides derivatives are known for their superior lectrochemical activities comparable to those of Paraquat (Methyl Viologen) but with larger amplitude of photochemical applications. Positively and negatively charged, surfactant like, Naphthalene Diimides, were synthesized. After detailed characterization of the Naphthalene Diimides including selfassociation and interaction with surfactant molecules, the interaction with Cerium Oxide nanoparticles was determined. Naphthalene Diimides interacted in a special manner with Cerium Oxide nanoparticles rendering hydrolytic inertness and novel photochromic behavior. The organic dye is proposed to adsorb in the crevices of the particles and furthermore forming stable dimers that accounts for the new photoactivities observed
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Estudo da dopagem de agregados para finalidade de uso em concretos estruturais / Study of aggregates doping applied to structural concretesTrigo, Ana Paula Moreno 03 September 2012 (has links)
Este trabalho apresenta um estudo sobre a técnica de dopagem em agregados química e mineralogicamente deficientes e tem como objetivo demonstrar que se houver a dopagem de agregados, ainda que haja o limitante das respectivas resistências destes materiais, eles poderão vir a ser utilizados em grandes obras com pleno êxito. A técnica apresenta-se como uma solução para a problemática de disponibilidade de bens minerais, atualmente em declínio em virtude de problemas de sustentabilidade ambiental, de zoneamentos restritivos e de usos competitivos do solo, tornando preocupantes as perspectivas de garantia de suprimento futuro. Por meio da impregnação inicial do agregado com aglomerantes de alto desempenho foi possível modificar sua textura, estabelecer ponte de ligação entre ele e a matriz do concreto e criar carapaça de proteção e reforço, atingindo-se fc28 = 60 MPa nos concretos lateríticos dopados. A eficiência da técnica foi avaliada comparando-se propriedades mecânicas e microestruturais de concretos não dopados (referência) e dopados. Para tanto, foram realizados ensaios de resistências à compressão, à tração por compressão diametral e à tração na flexão, absorção de água por imersão e microscopia eletrônica de varredura. Os resultados demonstraram ser possível melhorar agregados graúdos deficientes por meio da dopagem e obter concretos de comportamento comparável ou até superior a concretos usualmente considerados como de bom desempenho. Ainda que seja um estudo inicial, a técnica de dopagem revela-se promissora, com expectativa de uso em agregados normalmente considerados inadequados para concretos estruturais. / This thesis presents a study on the doping technique in aggregates disabled chemical and mineralogical and aims to demonstrate that with the technique, although there is a resistances limitation, these aggregates could be used with success in large projects. The doping technique is presented as a solution to the minerals availability problem, currently declining due to environmental sustainability problems, restrictive zoning and land competing uses, fact that worries the future supply security. By impregnating initial of the aggregate with high performance binders was possible to modify its texture, to establish a bridge between it and the concrete matrix and create shell protection and enhancement, reaching fc28 = 60 MPa in lateritic doped concrete. Mechanical and microstructural properties of reference concretes and doped concretes were compared to evaluate the doping efficiency. Testing of compressive strength, tensile strength by diametrical compression and tensile strength in bending, water absorption by immersion and scanning electron microscopy were performed. The results indicate that deficient coarse aggregates can be improved by the doping technique and it is possible to obtain specific behavior comparable or even superior to concrete usually considered to be of good performance. Although it is an initial study, the doping technique seems to be promising, with expected use in aggregates considered unsuitable for structural concrete.
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Avaliação do efeito do ácido docosahexaenoico e de seus hidroperóxidos na oligomerização de SOD1 em um modelo da doença esclerose lateral amiotrófica / Evaluation of the effect of docosahexaenoic acid and its hydroperoxides in oligomerization of SOD1 in a model of the disease amyotrophic lateral sclerosisAppolinario, Patricia Postilione 24 May 2013 (has links)
A Esclerose Lateral Amiotrófica (ELA) é uma doença progressiva e fatal causada pela degeneração seletiva dos neurônios motores do cérebro e medula. Dos casos familiares de ELA (fELA), 20% são causados por mutações pontuais no gene da sod1. O ácido docosahexaenoico (C22:6, n-3, DHA) é um ácido graxo altamente insaturado, sendo um dos principais ácidos graxos da massa cinzenta do cérebro. Estudos têm correlacionado mutações de SOD1 com a formação de agregados que poderiam ser induzidos por ácidos graxos insaturados. O objetivo deste estudo foi avaliar os efeitos e mecanismos do DHA e de seus hidroperóxidos (DHAOOH) na agregação de SOD1 in vitro. As análises de dicroísmo circular (CD) mostraram mudanças na estrutura secundária de ambas as proteínas apo-SOD1WT e G93A promovidas pelo DHA, resultando em aumento de superfície hidrofóbica e formação de estruturas do tipo beta-amilóide, como mostrado pelos ensaios do bis- ANS e Tioflavina, respectivamente. Estas mudanças resultam na formação de agregados amorfos como observado por microscopia eletrônica de varredura (MEV). Espécies de alto peso molecular foram observadas nas incubações do DHA com as formas apo da SOD1 por SDS-PAGE sob condições não redutoras e também por cromatografia de exclusão por tamanho. A formação dos agregados mostrou-se dependente de resíduos de Cys na sua forma desprotonada, visto que agregados não foram observados na presença de beta-mercaptoetanol e sua formação foi inibida na presença de bloqueador de tióis e em pH ácido. Além disso, análises por cromatografia de exclusão mostraram que a agregação é dependente da insaturação e conformação cis dos ácidos graxos. Comparativamente ao DHA, os hidroperóxidos do DHA tiveram um efeito menor na agregação de SOD1, porém revelaram a propriedade de induzir a dimerização covalente de SOD1. No geral, os dados mostram que o DHA induz a agregação de SOD1, através de um processo envolvendo a exposição de superfícies hidrofóbicas, formação de pontes dissulfeto e também de possíveis cross-links envolvendo reações do tipo \"ene-tiol\". / ALS is a progressive and fatal disease caused by selective degeneration of motor neurons in the brain and spinal cord. Twenty percent of familial ALS (fALS) cases are caused mainly by point mutations in the sod1 gene. Docosahexaenoic acid (C22:6, n-3, DHA) is a highly unsaturated fatty acid, wich is one of the main fatty acids in the cerebral gray matter. Studies have linked SOD1 mutations to the formation of aggregates that could be induced by unsaturated fatty acids. The aim of this study was to evaluate the effect of DHA on aggregation of SOD1 fALS mutants in vitro and its mechanisms. CD analysis shows changes in the secondary structure of both apo-SOD1WT and G93A promoted by DHA resulting in an increase in the surface hydrophobicity and formation of structures such as beta amyloid, which was also confirmed by bis-ANS assay and Thioflavin, respectively. These changes enhance the interaction of SOD1 and DHA, leading to amorphous aggregates as revealed by FESEM. Incubation of DHA with apo-SOD1 forms results in high-molecular weight species as detected by SDS-PAGE analyses under non-reducing conditions and also by size exclusion chromatography. This appears to require Cys residues in their thiolate forms because high aggregates are not observed under reducing conditions and also by size exclusion chromatography or at acidic pH. Also, size-exclusion chromatography indicates that the mutant apo-SOD1 aggregation is dependent on the unsaturation and cis-conformation of fatty acids. Compared to the DHA, DHAOOH had a minor effect on SOD1 aggregation, however revealed the ability to induce covalent dimerization of SOD1. Overall, the data suggest a mechanism of DHA aggregation, by a process involving exposure to hydrophobic surfaces, formation of disulfide bonds and also for possible cross-links involving reactions such \"thiol-ene\".
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Análise da influência da massa específica de agregados graúdos provenientes de resíduos de construção e demolição no desempenho mecânico do concreto. / Analyses of the influence of construction and demolition waste coarse aggregate porosity on the mechanical performance of concrete.Carrijo, Priscila Meireles 16 March 2005 (has links)
Em virtude de muitas dúvidas ainda existentes, referentes ao desempenho e durabilidade dos concretos com agregados de RCD reciclados, sua utilização até o momento é limitada, não chegando aos níveis desejáveis e necessários. Somam-se a essas, a falta de gestão, de ferramentas de controle de qualidade, de normalização e de melhoria nas operações unitárias de beneficiamento do RCD. Os agregados reciclados apresentam características físicas e comportamento bastante heterogêneo, o que dificulta sua utilização com confiabilidade, principalmente em situações que demandam um maior controle e responsabilidade por parte do material empregado, como no caso de concretos estruturais. A porosidade e absorção dos agregados reciclados influenciam, de maneira significativa, as propriedades do concreto fresco e endurecido. Mesmo que estes sejam separados por fases (concreto, argamassa e cerâmica), é possível encontrar porosidades variadas dentro de uma mesma fase. Portanto, não se pode afirmar que o comportamento de concretos com agregados de mesma fase será homogêneo. Por este motivo, para esta pesquisa os agregados reciclados vermelho (predominância visual de cerâmica vermelha) e cinza (predominância visual de materiais cimentícios) foram separados em quatro faixas de densidade (d<1,9; 1,9<d<2,2; 2,2<d<2,5; d>2,5 g/cm³). Foram analisados os resultados de resistência à compressão, módulo de elasticidade, absorção de água, índice de vazios, massa específica e consumo de cimento. Os resultados obtidos nos ensaios de avaliação das propriedades físicas e mecânicas dos concretos usando agregados vermelho e cinza e concretos com agregados convencionais foram analisados para quantificar a influência da porosidade dos agregados. Verificou-se que a influência da natureza mineralógica dos agregados (vermelho ou cinza) influenciou as propriedades de maneira menos intensa que sua porosidade. Além disso, os concretos produzidos com RCD de densidade inferior a 2,2 g/cm3 apresentaram menor resistência e módulo e maior absorção de água, tornando o concreto muito menos eficiente para aplicações estruturais. A separação dos agregados em faixas de densidade garantiu um comportamento bastante homogêneo dos concretos, quando se utilizou agregados da mesma faixa. Com isso, foi possível estabelecer uma correlação entre a porosidade dos agregados e o desempenho mecânico dos concretos. A separação por faixas de densidade se mostrou como um critério confiável de classificação e caracterização dos agregados para a fabricação de concretos, podendo ser utilizado em conjunto com a separação visual normalmente empregada. / Construction and Demolition Waste (CDW) aggregates have not yet been widely used in concrete applications due to the many doubts relating to its performance and durability. The lack of an appropriate CDW recycling management, standardization, an innovative process technology as well as faster, cheaper and accurate quality control techniques also limits the use of this material. The reliable use of recycled CDW aggregates, especially in major situations such as in structural concrete, is still difficult due to its heterogeneous physical characteristics and behavior. Fresh and hard concrete properties are significantly influenced by recycled aggregate porosity and water absorption. Even if aggregates are separated in phases by hand sorting (concrete, mortar and ceramics) it is possible to find different porosities within the same phase and, for that reason, concretes will also present heterogeneous behavior. In this direction, the two types of recycled aggregates used in this research named red (mainly constituted of red ceramics) and grey (mainly constituted of cimenticious materials) were separated in four density classes (d<1.9; 1.9<d<2.2; 2.2<d<2.5; d>2.5 g/cm³). The compressive strength, elastic modulus, water absorption, specific weight and cement consumption of concretes were analyzed. The mechanical and physical properties of concretes were studied in terms of the recycled aggregate porosity and comparisons of results obtained with concretes using red or grey recycled aggregates and with ordinary aggregates were carried out. It was verified that the concretes properties were mostly influenced by the aggregates porosity when compared to its phase. Recycled aggregates with bulk specific gravity under 2.2 g/cm3 provided a significant reduction of the compressive strength and the elastic modulus and an increase of water absorption, producing concretes less efficient for structural applications. The behaviour of concretes produced by aggregates within the same density class was found to be homogeneous. A relation between porosity of aggregates and mechanical performance of concrete was verified. The heavy media separation can be used, together with the hand sorting, as an efficient and reliable aggregate quality control method for the production of concretes.
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A study of carbonation in non-hydraulic lime mortarsLawrence, Robert Michael Heathcote January 2006 (has links)
Lime has been used in construction for millennia, and its value, especially in the field of conservation architecture, has only recently been rediscovered. Lime mortars harden through carbonation, and this thesis is a study of that process. The research conducted has resulted in the development of two novel techniques for the measurement and detection of carbonation. The first technique is a method of thermogravimetric analysis which allows the carbonation profile to be measured within an acceptable time-frame. The second technique is the use of drilling resistance measurement to visualise the carbonation profile. The potential of elemental analysis to measure the carbonation profile has also been identified. It has been demonstrated that the lime/water ratio has less impact on the compressive strength of air lime mortars than had previously been supposed. The change in the pore size distribution of air lime mortars caused by carbonation has been studied, and a theory has been proposed to explain this phenomenon. Five different forms of air lime binder were studied. The impact of these on the structural performance of the resultant mortars has been assessed. It was concluded that mortars made with lime putties perform better than mortars made with dry lime hydrate. Mortars made with dispersed hydrated lime appear to perform as well as mortars made with lime putties, but at a slower rate of strength growth. The use of extra mature lime putty does not appear to confer structural performance benefits when compared with ordinary lime putty. It has been shown that the use of calcitic aggregates can produce air lime mortars which perform as well as moderately hydraulic lime mortars. It is theorised that this phenomenon is not directly related to carbonation, but rather to a complex interaction of the granulometry, mineralogy, chemistry and porosity of the aggregate with the binder.
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