Hydration Mechanism
Mostrando 1-12 de 58 artigos, teses e dissertações.
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1. Cinza de biomassa rica em calcário como material carbonático em sistemas cimentícios de base Portland
Resumo O uso de materiais alternativos, em substituição ao clínquer, tem sido amplamente estudado, a fim de reduzir custos e minimizar os danos ambientais causados pela produção do cimento Portland. Investigou-se a influência do uso da cinza de algaroba (Prosopis juliflora), material rico em carbonato de cálcio, nos mecanismos de hidratação e forma�
Cerâmica. Publicado em: 2019-01
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2. Pollen has higher water content when dispersed in a tricellular state than in a bicellular state
ABSTRACT Pollen is generally dispersed in a sexually immature and somewhat dehydrated, metabolically quiescent state. Yet, in some species, pollen at anthesis is well-hydrated and metabolically active, and in 30 % of angiosperms pollen is dispersed after having formed its sperm cells. Pollen water content and sexual maturity may be correlated, either because
Acta Bot. Bras.. Publicado em: 30/07/2018
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3. Use of Opuntia ficus-indica (L.) Mill extracts from Brazilian Caatinga as an alternative of natural moisturizer in cosmetic formulations
ABSTRACT The aim of this work was the obtainment of Opuntia fícus-indica (L.) Mill extract for the development of cosmetic formulations and in vivo evaluation of its moisturizing effects. The formulations were tested for preliminary and accelerated stability. Organoleptic characteristics, pH values and rheological behavior were assessed. The evaluation of m
Braz. J. Pharm. Sci.. Publicado em: 2016-09
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4. CARACTERIZAÇÃO E VIABILIDADE DO USO DE HIDROGÉIS COMPÓSITOS POLI (ÁLCOOLVINÍLICO)/ATAPULGITA EM SISTEMAS DE LIBERAÇÃO DE FÁRMACO. / CHARACTERIZATION AND VIABILITY OF POLY (VINYL ALCOHOL)/ ATTAPULGITE COMPOSITES HYDROGELS IN DRUG DELIVERY SYSTEM.
Composites hydrogels were developed in film shape based on poly vinyl alcohol (PVA) using acidified attapulgite as crosslinking agent. The hydrogel composites were obtained in solution with amounts of attapulgite ranging from 0.05 to 2% in the polymer matrix in order to study its influence on the crystallinity, in the swelling properties and in the release o
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 10/02/2012
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5. Physiological and biochemical responses to drought stress in Barbados cherry
To evaluate physiological genotypic differences between two Barbados cherry genotypes (13- and 14-CPA) under water deficit, initial growth, water relations, and organic solute accumulation were evaluated in an experiment performed using four-month-old seedlings, which were subjected to four water treatments (100, 75, 50, and 25% of field capacity), with five
Braz. J. Plant Physiol.. Publicado em: 2012-09
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6. Combined effect of sodium sulphate and superplasticizer on the hydration of fly ash blended Portland® cement
Combined effect of polycarboxylate type superplasticizer and sodium sulphate on the hydration of fly ash blended Portland® cement has been studied by using different techniques. Water consistency, setting times, non-evaporable water contents, water percolation, air contents, compressive strengths and expansion in corrosive atmosphere were determined. Hydrat
Materials Research. Publicado em: 2010-06
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7. Influencia de la temperatura de curado: hidratación y resistencia de pastas de cemento con escoria
Nowadays it is well known that using blast furnace slag as partial replacements for Portland cement adds technological, economic and environmental benefits. Those are some of the reasons why cements containing several additions (blast furnace slag, fly ash, calcareous material, etc) are commonly used. In recent years, blended cements started to increase amou
Matéria (Rio de Janeiro). Publicado em: 2010
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8. Influência da cal hidratada nas idades iniciais da hidratação do cimento Portland - estudo em pasta. / Influence of hydrated lime on initial stages of hydration of Portland cement - paste study.
In the last decades, scientific and technological progress has shown a significant advance in the process of obtaining lime; however, there is gap knowledge with relation to its action when employed together with Portland cement. The use of lime in finishing mix mortars has only been positively associated to the fresh state plasticity and ability to deformat
Publicado em: 2008
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9. Atividade reprodutiva de Plagioscion squamosissimus (Heckel,1840) (Actinopterygii,Perciformes), no reservatório de Pedra, Rio de Contas, Bahia
We evaluated the reproductive aspects of the organization and characterization of oocytes and the maturational stages of Plagioscion squamosissimus in the reservoir of stone, river of Auditors, Bahia. The collections were bimonthly, conducted between november/04 and september/06. It was recorded during reproductive activity every year, with peaks in march/05
Publicado em: 2008
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10. Portland cement, fly ash and hydrated lime systems: hydration mechanism, microstructure and concrete carbonation. / Sistemas cimento, cinza volante e cal hidratada: mecanismo de hidratação, microestrutura e carbonatação de concreto.
A utilização de cinza volante na composição de material cimentício o torna mais sustentável, além de conferir à matriz hidratada características peculiares que melhoram o desempenho frente à ação de diferentes agentes deletérios. A principal desvantagem da utilização de pozolana no sistema cimentício é a maior susceptibilidade à carbonataç
Publicado em: 2008
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11. CARBONATION AND CAPILLARY ABSORPTION IN CONCRETES OF WHITE PORTLAND CEMENT WITH HIGH CONTENTS OF BLAST FURNACE SLAG AND CHEMICAL ACTIVATORS / CARBONATAÇÃO E ABSORÇÃO CAPILAR EM CONCRETOS DE CIMENTO PORTLAND BRANCO COM ALTOS TEORES DE ADIÇÃO DE ESCÓRIA DE ALTO FORNO E ATIVADOR QUÍMICO
The carbonation phenomenon, reaction between CO2 from the atmosphere in the presence of humidity with the Portland cement hydration products, induces pH reduction to levels that can cause the elimination of steels protective layer, enabling the corrosion mechanism of the steel structure to start.. This is one of the main pathologies in the reinforced concret
Publicado em: 2008
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12. XANTHAN AND GALACTOMANANN FROM SEEDS OF M. scabrella AS HYDROPHYLIC MATRICES OF THEOPHYLLINE / GOMA XANTANA E GALACTOMANANA (M. scabrella): DESENVOLVIMENTO DE MATRIZES HIDROFÍLICAS PARA LIBERAÇÃO MODIFICADA DE TEOFILINA
Directly compressed theophylline tablets were produced containing commercial Xanthan (X) (Keltrol) and a highly hydrophyllic galactomannan (G) from the seeds of Mimosa scabrella, (a Brazilian leguminous tree, called bracatinga) as a release-controlling agent, isolated or in mixture (X:G 1:1), at 8, 12.5 and 25% of gums. In the galactomannan extraction proces
Publicado em: 2005