Die bei Textilbetonbauteilen üblicherweise zum Einsatz kommenden Bewehrungen können sowohl aus Carbon oder AR-Glas bestehen. Aufgrund des Preises und der Verfügbarkeit hat AR-Glas gegenüber Carbon allerdings eine deutlich größere Verbreitung am Markt. Trotz der chemischen Modifikation zur Verbesserung der Alkalibeständigkeit von AR-Gläsern gegenüber E-Glas, kann bei AR-Gläsern ein nennenswerter Festigkeitsverlust infolge der Alkalität des Betons innerhalb der Lebensdauer eines Bauwerks festgestellt werden. Eine Möglichkeit den langfristigen Festigkeitsverlust zu reduzieren, ist der Aufbau einer Diffusionsbarriere um die einzelnen Rovings durch eine polymere Tränkung. Im Rahmen der vorliegenden Veröffentlichung werden mögliche Tränkungsmaterialien sowie die Auswirkungen dieser auf die Dauerhaftigkeit der textilen Bewehrungen anhand von Versuchen bewertet und ein Modell zur Prognose des langfristigen Festigkeitsverlustes polymermodifizierter Bewehrungen vorgestellt. / The reinforcement in TRC (Textile Reinforced Concrete) is usually made of alkali-resistant glass rovings due to their low price and availability on the market, but even the glass composition is changed compares to E-glass to increase its alkali resistance the durability in concrete is known to be unsatisfactory. One possibility to increase the durability is the application of a diffusion barrier around the reinforcement. The diffusion barrier can be made out of reactive polymeric coatings. Within the paper the results regarding the durability of AR-glass reinforcement achieved with a variety of reactive materials, mainly epoxy resins, will be presented as well as discussed. In addition to the results achieved in the laboratory, a model which allows long term predictions of the durability of polymer impregnated AR-glass reinforcements will be presented.

Geopolymer chemistry governs the formation of an X-ray amorphous aluminosilicate cement material. Binders form at ambient temperatures from a variety of different raw material sources, including industrial wastes. Early research in this field was based around investigating binder material properties; however, more recently, geopolymer formation chemistry has been intensively studied. Better understanding of the chemical processes governing geopolymer curing reactions will allow a wider variety of waste materials to be utilised and also the tailoring of binder properties for specific applications. (For complete abstract open document).

Thesis (Ph. D.)--University of Texas at Austin, 2007. / Vita. Includes bibliographical references.

Thesis (M.S.)--Brigham Young University. Dept. of Civil and Environmental Engineering, 2005. / Includes bibliographical references (p. 57-61).

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Submitted by hugo lira (hugovictorsb@gmail.com) on 2018-09-03T13:11:08Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) 1. Tese de Doutorado - Grafe Pontes.pdf: 3805661 bytes, checksum: dfa0075a7b7b500d45f3604fdd0ab8b0 (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2018-09-10T15:39:31Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) 1. Tese de Doutorado - Grafe Pontes.pdf: 3805661 bytes, checksum: dfa0075a7b7b500d45f3604fdd0ab8b0 (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2018-09-10T15:49:55Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) 1. Tese de Doutorado - Grafe Pontes.pdf: 3805661 bytes, checksum: dfa0075a7b7b500d45f3604fdd0ab8b0 (MD5) / Made available in DSpace on 2018-09-10T15:49:55Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) 1. Tese de Doutorado - Grafe Pontes.pdf: 3805661 bytes, checksum: dfa0075a7b7b500d45f3604fdd0ab8b0 (MD5) Previous issue date: 2018-05-02 / FAPEAM - Fundação de Amparo à Pesquisa do Estado do Amazonas / The use of chemical insecticides becomes important in Aedes aegypti control programs. Over the years, epidemiological studies have demonstrated the inefficiency of synthetic insecticides due to the resistance acquired with the use in activities related to vector control in tropical diseases, especially dengue. For a better effectiveness of vector control programs, the search for new alternatives is necessary. The interest in entomopathogenic fungi for biological control is in great growth. However, the work on controlling the different stages of life of A. aegypti and the transmission of mycoses between individuals and their offspring are still discrete. In order to contribute with new compounds and integrated control of dengue, the present project aims to evaluate the entomopathogenic activity of fungi isolated from Amazonian soil in larvae and adults of A. aegypti, and their residual effects on the life cycle considering the number of eggs and larvae and adults. The proposed methodology for this work is the use of conidia of fungal isolates previously selected by genera that have relevance in biological control or that demonstrate positive results when used in probe / sorting insects, Tenebrio molitor. For the application of the formulations conidia were used in aqueous suspensions for treatment in larvae, and for adults was used aqueous suspensions impregnated in filter paper placed in Kit of the World Health Organization used to evaluate the susceptibility of chemical insecticide. The present work proposes a practical methodology for sexing and separating adults through the selection of pupae, in order to evaluate the degree of infestation and the entomopathogenic effect on larvae and adults of A. aegypti. avoiding the premature death of the insect by the use of Castro's catcher at the time of adult withdrawal from the colony. The results obtained evidenced the potential of four fungal isolates IPC 2.1 and IPS 3.1 isolated from Amazonian soil, and two other isolates from other insects and from soil samples IBCB 66 and IBCB 425, widely used to control insects in agriculture, and evaluated for the control of larvae and adults of the mosquito vector dengue. The results between the two methodologies showed the best applicability for the fungal isolates and their use in the control of A. aegypti, responsible for a great social impact on the public health of the Amazon due to the transmission of several arboviruses. / O uso de inseticidas químicos tornou importante nos programas de controle do Aedes aegypti. Com o passar dos anos, os estudos epidemiológicos demonstraram a ineficiência dos inseticidas sintéticos devido à resistência adquirida com a utilização nas atividades relacionadas ao controle de vetores em doenças tropicais, especialmente dengue. Para uma melhor eficácia dos programas de controle de vetores, há necessidade da busca de novas alternativas. O interesse em fungos entomopatogênicos para controle biológico encontra-se em amplo crescimento. Entretanto, ainda são discretos os trabalhos no controle dos diferentes estágios de vida do A. aegypti, e a transmissão de micoses entre seus indivíduos e sua prole. Com o intuito de contribuir com novos compostos e no controle integrado da dengue, Febre Chikungunya e Zika vírus. O presente projeto tem como objetivo avaliar a atividade entomopatogênica de fungos isolados de solo da Amazônia em larvas, adultos de A. aegypti, e seus efeitos residual sobre o ciclo de vida considerando o número de ovos e larvas e adultos. A metodologia proposta para esse trabalho visa à utilização de conídios dos isolados fúngicos previamente selecionados por gêneros que tenham relevância no controle biológico ou que demonstrem resultados positivos quando utilizados em insetos sonda/triagem, Tenebrio molitor. Para a aplicação das formulações foram utilizados conídios em suspensões aquosas para tratamento em larvas, e para adultos foi utilizado suspensões aquosas impregnados em papel filtro colocados em Kit da Organização Mundial de Saúde utilizado para avaliação de susceptibilidade de inseticida químico. Os bioensaios foram realizados em condições de laboratório, avaliando-se o grau de infestação e o efeito entomopatogênico sobre as larvas e adultos de A. aegypti, O presente trabalho propõe uma metodologia prática para sexagem e separação de adultos por meio de seleção de pupas, evitando a morte prematura do inseto pelo uso de capturador de Castro no momento de retirada de adultos da colônia. Os resultados obtidos evidenciaram o potencial de quatro isolados fúngicos, IPC 2.1 e IPS 3.1 isolados de solo da Amazônia, e outros dois isolados de outros insetos e de amostras de solo, IBCB 66 e IBCB 425, amplamente utilizados para controle de insetos na agricultura, e avaliados para combate de larvas e adultos do mosquito vetor da dengue, Febre Chikungunya e Zika vírus. Os resultados entre as duas metodologias demonstraram a melhor aplicabilidade para os isolados fúngicos e sua utilização no controle do A. aegypti, responsáveis por grande impacto social na saúde pública da Amazônia devido a transmissão de diversas arboviroses.

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<p> Promoted and supported catalysts were studied with an electron probe microanalyzer. Investigations we re made on promoted fused iron ammonia synthesis catalysts regardirlg the general morphology of the catalysts, the distribution of promoters, and the reduction and poisoning processes . The effect of the promoters on the reduction process , the effect of the impurity silica on the promoter distributions and the nature of the poisoning are discussed. Supported catalysts were prepared by impregnating porous y-alumina spheres with solutions of chromium and/or copper compounds. Concentration profiles for chromium and/or copper , i.e., concentration as a function of distance from the center, were determined on sectioned spheres. Different distributions of these elements on the alumina support were obtained by varying the chemical used, the concentration and the amount of the solution impregnated. Explanations are given for the physical and chemical processes involved during the impregnation . The amount of chromium or copper impregnated is compared with the amount present in each particle. </p> / Thesis / Doctor of Philosophy (PhD)

Incorporation of chemicals into the internal matrix of cement or concrete, with later release occurring upon stimulation, alters the matrix parameters from those at the initial set. Permeability is reduced, for example, and therefore durability enhanced. The advantages of these designs would be the ability to reduce maintenance and repair costs in the initial building configuration and to delay the time of eventual repair. The components and the structure could take greater environmental abuse also. Permeability is significantly reduced by release of a polymer from wax-coated porous fibers upon heating to temperature of polymerization. Freeze/thaw damage is somewhat reduced by the timed release of linseed oil or antifreeze from porous aggregates due to the freezing action itself. These example designs using timed release mostly gave improved durability performance when compared to conventional treatments for durability or environmental distress. Concerns that significant strength reduction would occur due to heating or fiber loading were shown to be unfounded by our test results; indeed, heating and fiber inclusion increased strength. An adequate amount of wetting of the samples could be obtained with 2.75% volume of fibers; however, above a 2.75% volume of fibers, fibers do reduce the strength. Results were analyzed by the method of comparing results in the samples with factors varied to results in samples without variable factors, that is, by comparing to the controls. This research shows that timed internal release of chemicals into cement can be accomplished; it appears feasible and is potentially useful. Long-term tests need to be performed on such factors as chloride ion intrusion/ corrosion tests. Filled fiber, aggregate or prill manufacture, storage, and placement need to be researched and assessed for cost. Design of components using only targeted areas for release in the component and the use of time released fibers in reinforced cement laminates should be evaluated. / Ph. D.

An innovative sampling technique employing extractant impregnated membranes is presented for the selective sorption and stabilization of specific oxidation states of chromium. Polymer-based selective ion traps employing the extractants tricaprylmethylammonium chloride (Aliquat-336) and di-(2-ethylhexyl) phosphoric acid (DEHPA) were used for the selective removal and enrichment of the anionic forms of Cr(VI) and cationic forms of Cr(III), respectively. Results show Aliquat-336 and DEHPA effectively remove Cr(VI) and Cr(III) from aqueous solutions. Extraction efficiency is independent of source concentration from 1-50 ppm but is dependent upon time, pH of the source, ionic strength, extractant concentration, composition of source phase, and choice of stripping agent and stripping agent concentration. Optimum conditions for Cr(VI) and Cr(III) were determined to be 1 v/v% Aliquat-336 and 30 v/v% DEHPA; an extraction time of at least 3-5 days; source phase pH between 3-5; and 1 M NaOH/ 0.5 M HNO3 as stripping agent for Cr(VI) and Cr(III) species, respectively. Batch extraction efficiencies of 97 +/- 3 % were obtained for the optimal conditions. Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES) was used for total chromium determination. UV-VIS spectrometry was used for Cr(VI) determination. Scanning Electron Microscopy revealed the physical structure of the polymeric supports and subsequent impregnation was evidenced by the SEM images. X-ray photoelectron spectroscopic results provided the elemental composition of the Versapor-450 membrane to be 71. 5% C, 7.0% O, 9.5% Cl and 12.0% N. The Whatman PP membrane was and 100.0 % C. Elemental composition of 1 v/v% Aliquat-336 on Versapor-450 and Whatman PP membrane was 92.3% C, 0.8% O, 3.6% N, and 3.3% Cl and 94.3% C, 3.3% N, and 2.4% Cl, respectively. Elemental composition of 30 v/v% DEHPA on Versapor-450 and Whatman PP membranes were 78.8% C, 3.4% P, 17.8% O and 76.3% C, 19.3% O, 4.4% P, respectively. Column studies under simulated groundwater conditions utilizing the extractant impregnated membranes showed no statistical difference in Cr(VI) recoveries from those obtained in batch experiments. Cr(III) extraction revealed a statistical difference in analyte recovery vs. batch experiments. This is attributed to the lowered pH and cationic interferences present in simulated groundwater. / Ph. D.