Chlorides
Mostrando 37-48 de 135 artigos, teses e dissertações.
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37. Modelling chloride penetration in concrete using electrical voltage and current approaches
This paper reports a research programme aimed at giving a better understanding of the phenomena involved in the chloride penetration in cement-based materials. The general approach used was to solve the Nernst-Planck equation numerically for two physical ideal states that define the possible conditions under which chlorides will move through concrete. These
Materials Research. Publicado em: 04/03/2011
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38. Batch-wise adsorption, saxs and microscopic studies of zeolite pelletized with biopolymeric alginate
Removal of nitrates, sulfate and Zn(II) ions from aqueous solutions through adsorption onto biopolymeric alginate/clinoptilolite-rich tuff pellets was studied by using an equilibrium batch technique. The idea of this approach of biosorbent fabrication is to promote the native zeolite adsorption performance and thus to prepare more efficient amphoteric tailor
Brazilian Journal of Chemical Engineering. Publicado em: 2011-03
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39. Corrosão por cloretos em estruturas de concreto armado : uma meta-análise / Corrosion by chlorides in reinforced concrete structures: a meta-analysis
O concreto é o segundo material mais consumido no mundo, perdendo somente para água, justificando a importância de estudos que envolvam seu comportamento frente à durabilidade, e que objetivam a obtenção de estruturas com longas vidas úteis. Dentre as diversas manifestações patológicas que ocorrem nas estruturas de concreto armado, a corrosão das
Publicado em: 2011
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40. Quitosana modificada quimicamente atraves de cloretos organicos e o uso como fonte em remoção cationica / Chitosan chemically modified with organic chlorides and the use as source in cationic removal
The biopolymer chitosan was submitted to a series of reactions, with the purpose to explore the free amino group reactivity polymeric chain through reactions involving organic chlorides and primary amines compounds. Isophthaloyl dichloride and cyanuric chloride were used in the modifications, following by reactions with ethylenediamine or diethylenetriamine.
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 14/04/2010
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41. 1-(2,4-dichlorophenyl-1H-pyrazoles: Synthesis, Structural Analysis and Interactions with Cannabinoid Receptors CB1 / 1-(2,4-Diclorofenil)-1H-pirazóis: Síntese, Análise Estrutural e Interação com os Receptores Canabinóides CB1
A method to obtain fourteen enones [EtO2CC(O)C(R2)=C(R1)OR, where R = H, Me; R1 = Pr, Ph, 4-MeOC6H4, 4-MeC6H4, 4-FC6H4, 4-ClC6H4, 4-BrC6H4, 4-NO2C6H4, Fur- 2-yl; R2 = H; R1,R2 = -(CH2)3-, -(CH2)4-, -(CH2)5-, -(CH2)6-, 3,4-dihydronaphthalen-2-yl] from acylation of acetals with ethyl oxalyl chloride is reported. The cyclocondensation reaction of these substrat
Publicado em: 2010
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42. Estudo do ingresso de cloretos em concretos localizados no litoral norte do Rio Grande do Sul / Study the entry of chlorides in concrete structures in the north of Rio Grande do Sul
As estruturas de concreto armado existentes em regiões marítimas são fortemente atacadas por agentes agressivos, sendo os cloretos os causadores dos maiores danos quando atingem níveis críticos, afetando de forma significativa a vida útil do concreto. Nos últimos anos a comunidade científica vem realizando pesquisas relativas à penetração de clore
Publicado em: 2010
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43. PENETRAÇÃO DE CLORETOS EM CONCRETOS COM DIFERENTES TIPOS DE CIMENTO SUBMETIDOS A TRATAMENTO SUPERFICIAL / CHLORIDE PENETRATION IN CONCRETE PRODUCED WHIT DIFFERENT CEMENT TYPES AFTER SURFACE TREATMENT
As características de durabilidade devem ser parâmetros de concepção das estruturas de concreto tanto quanto a sua resistência à compressão. O concreto deve manter a integridade frente aos agentes que o danificam, além de atuar como camada protetora à entrada de substâncias que venham a promover a corrosão das armaduras em seu interior. A corrosã
Publicado em: 2010
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44. Contribution to the development of performance specifications for concretes containing blast furnace slag / Contribuição ao desenvolvimento de especificações por desempenho para concretos com escoria de alto-forno
In 2008 alone, the annual steel production in Brazil was around 31 million tons. The steel production process generates an average of 500 kg of residues and co-products per ton of steel. From this total, 70% corresponds to the slags. Although investigating the increase of blast furnace slag use is of extreme importance for the concrete and steel industries s
Publicado em: 2010
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45. A QUALIDADE DA ÁGUA DOS AÇUDES DE CARIRA E DO BURI / CHARACTERIZATION OF WATER QUALITY IN BURI RESERVOIR FREI PAULO/SE
One of the most important natural resources in the Earth is, without a doubt none, the water. Had to constant periods of drought that characterize the semibarrens climate of wasteland in Brazilian northeastern, people faces serious problems of water scarcity and consequent lack of food. To try to minimize the lack of water, some reservoirs were built in nort
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 15/12/2009
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46. Tratamento de esgoto sanitário em sistemas alagados construídos utilizando Typha angustifolia e Phragmites australis / Sanitary sewer treatment in constructed wetlands system using Typha angustifolia and Phragmites australis
This study aimed to assess the efficiency of two vegetal species in the treatment of the sanitary sewer, in constructed wetlands system. Specifically, it aimed to evaluate the efficiency of the species Typha angustifolia (narrow-leaf cattail) and Phragmites australis (common reed), in their possible combinations, in the treatment of the sanitary sewer, in a
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 28/08/2009
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47. Synthesis of new disulfonamides from different substituted diamino pyridines
A series of novel disulfonamide derivatives were synthesized and characterized by FT-IR, ¹H NMR and MS techniques. In order to prepare new disulfonamides, at first we synthesized new diamines containing a pyridine ring. Then, they have been reacted with sulfonyl chlorides to give corresponding disulfonamides.
Eclética Química. Publicado em: 2009
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48. Ruminal and metabolic parameters of sheep induced to sub-acute ruminal acidosis and fed with probiotic, monensin and selenium yeast / Parâmetros Metabólicos e Ruminais de Ovelhas Induzidas à Acidose Ruminal Sub-Clínica, Suplementadas com Probiótico, Monensina e Selênio Levedura
The aim of this study was to observe the efficiency of probiotics, monensin and selenium yeast fed to sheep induced to sub-acute ruminal acidosis (SARA) on the maintenance of normal ruminal and metabolic parameters. Thirty six sheep that averaged 12 months old and 31 8 kg of body weight were used. The sheep were kept in a confinement system, receiving a diet
Publicado em: 2009