Thesis (Ph.D. (Ichthyology and Fisheries Science))--Rhodes University, 2006.

Thesis (M.S.) University of Missouri-Columbia, 2006. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (June 27, 2007) Includes bibliographical references.

Στόχος της εργασίας αυτής είναι η καταγραφή και αξιολόγηση της ποιότητας δέκα παραλιών του νομού Αχαΐας, καθώς και η σύγκριση των μικροβιολογικών και γεωλογικών στοιχείων που διεξάγονται μέσω μηνιαίων επαναλαμβανόμενων δειγματοληψιών και αναλύσεων. Εβδομήντα δείγματα άμμου συλλέχθηκαν μηνιαία, σε χρονικό διάστημα επτά μηνών και ακολούθησαν αναλύσεις όσον αφορά τα εξής βακτήρια: ολικά κολοβακτηριοειδή, e.coli και εντερόκοκκους. Παράλληλα πραγματοποιήθηκαν γεωλογικές αναλύσεις των δειγμάτων, όσον αφορά το μέγεθος των κόκκων, την σφαιρικότητα, την στρογγύλωση καθώς και τον υπολογισμό των στατιστικών τους παραμέτρων. / The aim of this paper is to record and evaluate the quality of ten beaches of Achaia, and to compare the microbiological and geological data held by recurring monthly sampling and analysis. Seventy samples of sand were collected monthly, over a period of seven months, followed by analyzes of the following bacteria: total coliforms, e.coli and enterococci. Furthermore, a geological analysis of the samples for grain size, the sphericity and the calculation of statistical parameters.

Made available in DSpace on 2014-06-11T19:28:34Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-03-06Bitstream added on 2014-06-13T20:18:25Z : No. of bitstreams: 1 souzafilho_mp_me_guara.pdf: 3830984 bytes, checksum: 7c2960cef5b04e4cbf20952bbc3f0443 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Este trabalho teve como objetivo o desenvolvimento das técnicas fundição de semicubos do trem de pouso principal do cargueiro C-115 Buffalo da Força Área Brasileira, pelo processo de fundição de liga de magnésio em moldes de areia a verde para atender as necessidades emergenciais nas atividades de apoio logístico, tático e transporte. Por ser um item estrutural cujas exigências em relação às propriedades de engenharia e segurança são rigorosas, foi necessário o desenvolvimento de técnicas de fundição diferenciadas para a obtenção do modelo com suas respectivas superespessuras de contração e usinagem; ângulos de saída; sistemas especiais de canais de alimentação; molde preparado com areia sintética, bentonita, enxofre, ácido bórico e água; magnésio, alumínio, zinco e alumínio-manganês de grau metalúrgico para a obtenção da liga; tratamento e refino do banho metálico, técnica de vazamento com frentes de alimentação simétricas; controle de qualidade por meio de inspeção visual, análise da composição química e metalográfica das fases e constituintes da liga, ensaios mecânicos e radiográficos para qualificação do fundido, conforme padrões aeronáuticos. Os ensaios apresentaram resultados cujos valores obtidos foram comparados com os padrões aeronáuticos internacionais, permitindo viabilizar a transferência desse desenvolvimento para o processo produtivo de forma a atender necessidades emergenciais e estimular a evolução do setor aeronáutico do País. / This work had as objective the development of the techniques of semicubes casting of the main landing gear of the C-115 Buffalo freighterm from Brazilian Air Force, by the process of magnesium alloy casting in green sand molds to attend to the emergent necessities in the activities of logistic, tactical support and air service. The creation of the Project of Nationalization of Aeronautical Components was necessary for the maintenance of the operationalization of the aircraft and to prevent the collapse of the fleet. Aeronautical wells are a structural item whose requirements in relation to the security and engineering properties are rigorous, it was necessary the development of differentiated techniques of casting for the attainment of the model with its respective superthicknesses contraction adn machining; pattern draft; special gate systems; mold prepared in synthetic sand, bentonite sand, sulphur, acid boric and water; magnesium, aluminium, zinc and aluminum-manganese of metallurgical degree for obtention of the alloy; treatment and refining of the metallic bath, pouring technique with symmetrical fronts of feeding; quality control by means of visual inspection, analysis of the chemical and metallographic composition of the phase and mechanical and radiografic constuent of the alloy, assays for qualification of the casting, as aeronautical standards. The assays had presented resulted whose gotten values had been compared with international aeronautical standards, allowing to make possible the transference of this devolopment for the productive process to pay attention to emergency necessities and to stimulate the evolution of the aeronautical sector of the Country.

Sand ramps are widespread but understudied landforms which have the potential to provide detailed palaeoenvironmental information in dryland regions. This thesis investigates the utility of sand ramps as late Quaternary palaeoenvironmental archives by addressing two research questions: (1) What are the main controls on sand ramp formation in southern Africa? (2) What does the sand ramp record tell us about late Quaternary palaeoenvironments in southern Africa? The distribution of sand ramps in southern Africa was surveyed using Google Earth™ and 75 features were identified in southern Namibia. Ten of these sand ramps, and an additional feature from South Africa, were studied in the field. Sediments and morphology were mapped and a total of 64 OSL dates, 96 sediment samples, 10 heavy mineral assemblages and OSL sensitivity data from 8 samples were examined. The distribution of sand ramps suggests formation is dependent on (1) sediment supply, (2) accommodation space, (3) persistent unidirectional wind and (4) a variable semi-arid to arid climate. Chronologies and sediment analyses indicate individual sand ramp accumulation is locally controlled by sediment supply modulated by the availability, and nature, of the accommodation space. Comparison between the Namibian and South African sand ramps suggests considerable regional variation in the factors controlling sediment supply. The Namibian sand ramps show an affinity to local ephemeral river channels. Periods of dated sand ramp activity in multiple features are interpreted as periods of increased regional fluvial activity. Significant activity occurred at ~21-12 ka (with peaks at 21-18.5 ka and 14.5-12 ka), ~8.5-7.5 ka and ~2 ka. Some activity is also indicated at 85-65 ka and 45-35 ka. These results correspond well to regional records. Overall, this study demonstrates that sand ramps can provide palaeoclimatic information on both the local and regional scale but only if a number of caveats are taken into consideration.

Submitted by Jos? Henrique Henrique (jose.neves@ufvjm.edu.br) on 2018-09-12T18:39:06Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) yrllan_ribeiro_sincura.pdf: 1372727 bytes, checksum: 658bffd6fd52f41fbd207a828e8d098a (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2018-10-02T16:31:44Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) yrllan_ribeiro_sincura.pdf: 1372727 bytes, checksum: 658bffd6fd52f41fbd207a828e8d098a (MD5) / Made available in DSpace on 2018-10-02T16:31:44Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) yrllan_ribeiro_sincura.pdf: 1372727 bytes, checksum: 658bffd6fd52f41fbd207a828e8d098a (MD5) Previous issue date: 2018 / Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM) / A leishmaniose visceral (LV) ? uma doen?a altamente letal quando n?o tratada e de car?ter reemergente. ? transmitida atrav?s da picada do flebotom?neo f?mea da esp?cie Lutzomyia longipalpis, inseto com grande distribui??o nas Am?ricas. O controle vetorial ? realizado atrav?s da aplica??o de inseticidas piretr?ides sint?ticos residuais de a??o r?pida sobre os insetos como a ?-cipermetrina e a deltametrina. Nos ?ltimos tempos tem se observado o surgimento de popula??es resistentes o que tem aumentado o interesse pela descoberta de novas mol?culas que possam ser utilizadas no controle de vetores. As plantas s?o um importante e promissor campo de pesquisa, uma vez que j? produzem mol?culas com a??o inseticida. Este estudo objetivou analisar a a??o inseticida de extratos de folhas e cascas de Protium heptaphyllum sobre Lutzomyia longipalpis selvagens. Para isso foram confeccionados extratos hidroalco?licos, etan?licos e ciclo- hex?nicos das folhas e cascas de Protium heptaphyllum. Nestes foram realizados estudos fitoqu?micos para prospec??o de classes de compostos secund?rios com a??o biol?gica. Os bioensaios foram realizados em potes pl?sticos adaptados e utilizou-se flebotom?neos Lu. longipalpis selvagens, oriundos da comunidade de Aroeira em Diamantina-MG. Obtivemos como resultado dos estudos fitoqu?micos, diversas classes de metab?litos secund?rios como terpenos, esteroides, taninos, flavonoides, alcaloides e saponinas, com destaque para os extratos de folhas onde foi observado um maior n?mero de classes em rela??o ?s cascas. Os bioensaios realizados evidenciaram uma a??o inseticida dos extratos hidroalco?licos e ciclo- hex?nicos que tiveram resultados estatisticamente semelhantes ? ?-cipermetrina. Apesar de composi??o qu?mica semelhante as demais, os extratos etan?licos apresentaram uma baixa atividade sobre os insetos. Com isso, conclu?mos que Protium heptaphyllum, possui atividade inseticida sobre Lu. longipalpis. Dessa forma, este estudo contribui com o desenvolvimento de m?todos de controle de insetos mais eficientes e menos agressivos aos humanos e outros animais. / Disserta??o (Mestrado) ? Programa de P?s-gradua??o em Biologia Animal, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2018. / Visceral leishmaniasis (VL) is a highly lethal disease when untreated and reemerging. It is transmitted through the bite of the female sand fly Lutzomyia longipalpis, a large-dose insect in the Americas. Vector control is performed through the application of fast acting residual synthetic pyrethroids on insects such as cypermethrin and deltamethrin. In recent times has been observed the emergence of resistant populations which has increased interest in the discovery of new molecules that can be used in the control of vectors. Plants are an important and promising field of research, since they already produce molecules with insecticidal action. This study aimed to analyze the insecticidal action of leaves and bark extracts of Protium heptaphyllum on wild Lutzomyia longipalpis. Hydroalcoholic, ethanolic and cyclohexanic extracts of the leaves and bark of Protium heptaphyllum were made. In these, phytochemical studies were found to identify groups of individuals with biological action. The bioassays were carried out in adapted plastic pots and wild Lu. longipalpis were used, originating from the community of Aroeira in Diamantina-MG. We obtained as a result of the phytochemical studies, several classes of secondary metabolites such as terpenes, steroids, tannins, flavonoids, alkaloids and saponins, especially leaf extracts where a greater number of classes were observed in relation to the bark. The bioassays performed showed an insecticidal action of hydroalcoholic and cyclohexane extracts that had statistically similar results to cypermethrin. Despite chemical composition similar to the others, the ethanolic extracts presented a low activity on the insects. From this investigation, we conclude that Protium heptaphyllum has insecticidal activity on Lu. longipalpis. Thus, this study contributes to the development of insect control methods that are more efficient and less aggressive to humans and other animals.

Offshore production fluids from the reservoir are often transported in pipelines from the wellheads to the platform and from the platform to process facilities. At low flow velocity water, sand or liquids like condensate could settle at the bottom of pipelines that may lead to grave implications for flow assurance. During shutdown the settled heavy liquid (e.g. water), could result in corrosion in pipelines, while following restart stages the settled water could form water plugs that could damage equipment, while settled sand could also form a blockage that needs to be purged. Furthermore, there is a requirement to know the quantity of water and base sediment for fiscal metering and custody transfer purposes. A series of experiments were carried out to observe low water cut in oil and water flows in four inch diameter pipeline. Similarly low sand concentrations in water and sand, water, air and sand flows were observed in two inch diameter pipelines. Conductive film thickness sensors were used to ascertain structural velocities, height and dense phase fractions. Comparisons are made between two cases in order to gain better understanding of the behaviours and dispersal process of low loading denser phase in multiphase flows. The arrangement enabled production of flow regime maps for low water cut oil and water flow, as well as water sand and water, air and sand flows, structural velocities and denser phase removal velocities were also ascertained. Actual in-situ liquid velocities were obtained experimentally. A novel detection of sand in water and water and sand flows was produced. The experimentally obtained film thickness was in agreement with two fluid model predictions. Thus, confirming use of conductive sensors for dense phase classification, film thickness, velocity and holdup measurements in pipelines.

Agricultural practices face a difficult dilemma of producing enough food for a growing population and evolving to greatly diminish its large impact on the environment. Soilless cultures such as hydroponics has been put forth as an alternative solution due to the possibility of larger yields and, in some departments, less impact on the environment. This study sought to investigate if there are any statistically proven differences in biomass gain for Ocimum basilicum when growing hydroponically or in course sand with full nutrient treatment, as well as growing with a calcium deficiency. Key findings show that full nutrient treatment gathered few to none differences, whilst calcium scarcity resulted in greater biomass and greater leaf biomass when planted in sand, whilst the water culture displayed less chlorophyll degradation. Due to challenges in methodology the study would benefit from being undertaken again with greater scientific precision, but variants can also be explored such as different growing mediums and nutrient scarcities. Soil-based growing is considerably more forgiving to mistakes and errors rather than soilless cultures, and so, for the positive qualities of hydroponics (space efficiency, no runoff, more effective use of resources, no pesticides/herbicides, less transport, etc.) to be effectual, knowledge, experience and further investigation is required.

A destinação adequada do sedimento extraído de corpos de água urbanos, por processos de dragagem, depende da viabilidade de estratégias de destinação sustentáveis, sendo uma delas a utilização deste resíduo na construção civil. Este trabalho tem por objetivo contribuir no estudo de viabilidade da utilização de areias de dragagem, como agregado miúdo para a confecção de argamassas e concretos não estruturais. Neste sentido, buscou-se avaliar a viabilidade de emprego do sedimento dragado do Arroio Dilúvio, localizado em Porto Alegre, como alternativa ao agregado miúdo comercialmente disponível na região. Para tanto, dois grupos de ensaio foram propostos: a) ensaios de caracterização do resíduo (constituição, granulometria, módulo de finura, massa específica, presença de impurezas orgânicas e teor de matéria orgânica, avaliação petrográfica, lixiviação de metais pesados); e b) ensaios de avaliação da qualidade do resíduo como agregado (através da moldagem de corpos de prova de argamassa e realização de testes de resistência mecânica, resistência de aderência, lixiviação de metais pesados e absorção de água). Nos ensaios de caracterização realizados observou-se que o teor de matéria orgânica, determinado por perda ao fogo, ficou abaixo do previsto. Já, os ensaios de contaminação orgânica, apesar de mostrarem resultados parasitológicos e de coliformes positivos, apresentaram parâmetros inferiores aos anteriormente encontrados pelo DMAE. Quanto às argamassas produzida com o resíduo, obteve-se um desempenho mecânico razoável, levemente inferior ao obtido com areia Normal do Rio Tietê e areia comercial do rio Jacuí. Nos ensaios de absorção se observou que a argamassa com areia do Dilúvio tende a mostrar um teor de absorção mais elevado que as demais, o que deve ser levado em conta para fins de análise da durabilidade. Um importante resultado é que os ensaios de lixiviação, que indicam a possibilidade de contaminação ambiental, indicaram que os metais contaminantes da areia ficam encapsulados na argamassa, mesmo após moagem da argamassa. Assim, apesar das restrições quanto à assimetria granulométrica, não há fatores de risco que impeçam a utilização desse agregado, desde que se leve em consideração as suas limitações de uso. O estudo aponta, portanto, para a potencialidade de uso deste material, como agregado alternativo para a construção civil, evitando a necessidade de deposição final do mesmo, que sobrecarrega aterros urbanos. Palavras-chave: Argamassas, areias dragadas, resíduos, lixiviação. / The correct disposal of sediment extracted from urban bodies of water for processes of dredging depends on the viability of strategies for sustainable destination, one being the usage of this waste in civil construction. The goal of this paper is to contribute to the study of viability of dredged sand as a fine aggregate in mortar and concrete non-structural. In this sense, we sought to evaluate the feasibility of using the dredged sediment from Dilúvio creek in Porto Alegre as an a alternative to fine aggregate, commercially available in the region. Two kinds of tests were performed:a) waste characterization (size, fineness module, specific mass, organic impurities, organic matter content, petrographic evaluation, leaching of heavy metals) and b) tests of residue quality as aggregate (through the molding of test specimens of mortar and tests of strength, bond strength , leaching of heavy metals and water absorption). In the characterization tests , it was observed that the organic matter content, determined by loss on ignition, was below expectations. On the other hand, tests of organic contamination, despite showing parasitologically and coliform positives, proved lower parameters than previously found by DMAE. As for the mortars produced with the residue obtained a reasonable mechanical performance, slightly lower than those with normal sand of Tietê River and commercial sand of Jacuí River. In absorption tests it was observed that the mortar with sand of Dilúvio tends to show a level of absorption higher than the others, which must be taken into account for purposes of durability analysis. An important result is that the leaching tests that indicate the possibility of environmental contamination, indicated that the metal contaminants are encapsulated in the sand mortar, even after grinding mortar. Thus, despite the restrictions on the particle size asymmetry, there are no risk factors that preclude the use of this aggregate, since it takes considerate the limitations of use. The study therefore point to the potential use of this material as an alternative aggregate for civil construction, avoiding the need for final disposal of the same that overloads the urban landfills.

A utilização do concreto auto-adensável (CAA) vem aumentando consideravelmente, no Brasil e no mundo. Com isso, há mais interesse em estudos práticos e teóricos a respeito do material, porém a maioria realizada está centrada em propriedades mecânicas da mistura no estado endurecido. Poucos estudos estão voltados para uma das áreas de maior lacuna: a dosagem. Os métodos de dosagem existentes para o CAA ou são experimentais, baseados na experiência do executor, ou são dependentes de tabelas determinadas a partir de materiais de difícil reprodução em outros locais. Com o intuito de ajudar a resolver este problema, foi proposto um método de dosagem experimental para CAA nesta tese. Este método visa a dosagem de CAA através de ensaios simples que determinem a composição dos agregados, de forma que o empacotamento granular apresente a menor quantidade de vazios possível, a fim de se minimizar o consumo de pasta na mistura. O método utiliza conceitos novos e já consagrados de outros métodos, como o IPT/EPUSP (Helene e Terzian, 1992), o proposto por Tutikian (2004), o de O´Reilly (1992) e o Modelo de Empacotamento Compressivo (CPM) (De Larrard, 1999). Para a comprovação da eficácia deste método, foram dosadas seis famílias de CAA, sendo três com areia fina e outras três com cinza volante, formando pares dosados por diferentes métodos. Entre as seis famílias, duas utilizaram o método de Tutikian (2004) e quatro o método proposto, porém primeiramente com uma faixa de agregado graúdo e após com duas granulometrias de brita, proporcionando famílias com o esqueleto granular mais compacto. Por fim, foi realizada uma família de concreto convencional (CCV). Os CAA dosados através deste novo método são de obtenção mais simples e menos trabalhosa, dependendo menos da experiência do executor, e os resultados mostraram que estes podem ser mais econômicos e com as propriedades no estado endurecido similares ou até vantajosas em relação às dos CCV e a dos outros CAA, principalmente o com duas granulometrias de agregado graúdo. / The utilization of self compacting concrete (SCC) has been increasing considerably throughout Brazil and the world. Hence, there has been more interest in theoretical and practical studies regarding the issue; however, the majority of such studies have been focused on the mechanical properties of the mixture in the hardened state. Very few studies have been focused on the subject of the dosage. The existing methods of dosage for SCC are either experimental, based on the experience of the executor, or are dependent on customized charts based on local materials which are very difficult to reproduce. With the intention to aid in the solution of this problem, an experimental dosage method was proposed in this thesis. This method aims at the dosage of SCC through simple tests that determine the composition of the aggregates, so that the packing density presents the least amount of voids, in order to minimize the consumption of binder in the mixture. The method uses new concepts and some concepts already determined from other methods, such as the IPT/EPUSP (Helene e Terzian, 1992), the one proposed by Tutikian (2004), the O´Reilly (1992) and the Compressive Packing Model (CPM) (De Larrard, 1999). In order to substantiate the efficienty of this method, six families of SCC were carried out, three of those with fine sand and the remaining three with fly ash, forming three pairs dosed by different methods. Amongst the six families, two used the Tutikian method (2004) and the other four families used the proposed method, which were divided into two subgroups; two with one class of gravel and the remaining subgroup utilizing two classes of gravel, supplying each family with a more compact granular skeleton. As a control group, a test family of conventional concrete (CCV) was produced. The SCC designed through this new method is simpler to obtain and requires less labor, depending less on the experience of the executor. The results present themselves as more economical and with the properties in the hardened state quite similar or even enhanced in relation to the ones of the CCV and the other SCC, specially with two classes of gravel.