Artigos científicos, teses e dissertações
Publicados nas melhores instituições de ensino

Surface treated fly ash filled modified epoxy composites

Fly ash, an inorganic alumino silicate has been used as filler in epoxy matrix, but it reduces the mechanical properties due to its poor dispersion and interfacial bonding with the epoxy matrix. To improve its interfacial bonding with epoxy matrix, surface treatment of fly ash wa...

Ver documento
Método de dosagem de concreto pelo volume de pasta com emprego de cinza volante / Concrete mix-proportioning method by cement paste volume using fly ash

This study was developed in order to create and a streamlined methodology of concrete mix proportioning using fly ash to reduce the cement content and an intensive use of a pollutant contributing to the increase of sustainability in construction through reducing consumption of cl...

Ver documento
Process parameter optimization for fly ash brick by Taguchi method

This paper presents the results of an experimental investigation carried out to optimize the mix proportions of the fly ash brick by Taguchi method of parameter design. The experiments have been designed using an L9 orthogonal array with four factors and three levels each. Small ...

Ver documento
Effect of Curing Temperature, Activator Solution Composition and Particle Size in Brazilian Fly-Ash Based Geopolymer Production

The geopolymer binder is a relatively new class of inorganic binding material of elevated mechanical strength and good chemical properties. This can be produced using clay minerals or byproducts of the industrial processes, such as metakaolin, fly-ash and blast furnace slag. In t...

Ver documento
Integrated Synthesis of Zeolites Using Coal Fly Ash: Element Distribution in the Products, Washing Waters and Effluent

Coal fly ash has been proposed as an alternative raw material for zeolite synthesis, however, the mobilization of toxic elements of this material into zeolite products, washing water and effluent is rarely addressed. In this study, Brazilian coal fly ash was used in the integrate...

Ver documento
Development of a Laboratory-Scale Leaching Plant for Metal Extraction from Fly Ash by Thiobacillus Strains

Semicontinuous biohydrometallurgical processing of fly ash from municipal waste incineration was performed in a laboratory-scale leaching plant (LSLP) by using a mixed culture of Thiobacillus thiooxidans and Thiobacillus ferrooxidans. The LSLP consisted of three serially connecte...

Ver documento
Behaviour of cementitious matrices subjected to the combined action of chloride ions and carbonation

ABSTRACT Carbonation and chloride action are the two leading causes of degradation in reinforced concrete structures. Despite the combined action of these two mechanisms being a reality, there is little research on the effect of this combination in cementitious matrices. Furtherm...

Ver documento
Prediction total specific pore volume of geopolymers produced from waste ashes by fuzzy logic

In the present work, total specific pore volume of inorganic polymers (geopolymers) made from seeded fly ash and rice husk bark ash has been predicted by fuzzy logic. Different specimens, made from a mixture of fly ash and rice husk bark ash in fine and coarse form together with ...

Ver documento
The use of fly-ash and rice-hull-ash in Al/SiCp composites: a comparative study of the corrosion and mechanical behavior

The corrosion characteristics and mechanical behavior of Al/SiCp/spinel composites prepared by reactive infiltration with fly-ash (FA) and rice-hull ash (RHA) -both with recycled aluminum- were investigated. MgAl2O4 is formed in situ during infiltration in the temperature range 1...

Ver documento
Adsorption isotherm studies of BOD, TSS and colour reduction from palm oil mill effluent (POME) using boiler fly ash

Palm oil is one of the two most important vegetable oils in the world's oil and fats market. The extraction and purification processes generate different kinds of waste generally known as palm oil mill effluent (POME). Earlier studies had indicated the possibility of using boiler...

Ver documento
Physical-mechanical behavior of alkali-activated materials produced by the one-part method based on fly ash and rice husk ash

Abstract The study on the physical-mechanical properties of alkali-activated materials (AAM) produced by the ‘one-part’ method was carried out. For this, residues such as fly ash and rice husk ash (RHA) were used. The alkaline activator (NaOH) was calcined together with RHA for 2...

Ver documento
Remediação de drenagem ácida de mina usando zeólitas sintetizadas a partir de cinzas leves de carvão

Zeolitic material was synthesized from coal fly ashes (baghouse filter fly ash and cyclone filter fly ash) by hydrothermal alkaline activation. The potential application of the zeolitic product for decontamination of waters from acid mine drainage was evaluated. The results showe...

Ver documento
Development of silicotic lesions in the lungs of rats pre-exposed to coal fly ash.

The development of silicotic lesions was studied in the lungs of rats pre-exposed to a pulmonary load of coal fly ash. Exposure to quartz alone increased the wet weight, dry weight, and collagen content of the lungs. These changes were associated with an increase in the activity ...

Ver documento
Evaluation of the Sustainability of Integrated Hydrothermal Synthesis of Zeolites Obtained from Waste

The high Si and Al contents in the amorphous phase of coal fly ash have been used for its conversion into zeolites. This process converts a toxic low-value by-product into a product used in a number of environmental applications, but has the disadvantage of introducing contaminan...

Ver documento
Estimation of fatigue lives of fly ash modified dense bituminous mixtures based on artificial neural networks

This study deals with estimation of fatigue lives of bituminous mixtures using artificial neural networks. Different types of fly ash were used as filler replacing agents in a dense bituminous mixture. Fatigue tests were performed using repeated load indirect tensile test apparat...

Ver documento
Statistical analysis of mechanical properties of mortars with fly ash and waste tire rubber

Resumo Este artigo tem como objetivo efetuar a análise estatística dos efeitos da inclusão da borracha de pneus inservíveis e cinza volante oriunda de usinas termelétricas como componentes da argamassa para revestimento de edificações. Foram produzidas argamassas de referência e ...

Ver documento
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, comp...

Ver documento
Dioxin concentrations in the blood of workers at municipal waste incinerators.

OBJECTIVES--Increased concentrations of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzo-furans (PCDFs) in pooled blood samples from workers at municipal waste incinerators have been reported. This study was undertaken to confirm these results in individual b...

Ver documento
Influence of local raw materials on the mechanical behaviour and fracture process of PVA-SHCC

This paper addresses the results of an investigation on the influence of the Brazilian raw materials on the mechanical performance of Strain Hardening Cementitious Composites (SHCC). The mixtures were produced with variations of fly ash/cement and sand/cement proportions and with...

Ver documento
The influence of separately and combined bentonite and kaolinite as binders for pelletization of NaA zeolite from coal fly ash

Abstract Pelletization of zeolitic materials is required to facilitate their practical industrial and commercial applications. Zeolite-NaA was synthesized from fly ash by the fusion method and shaped into spherical granules. Bentonite, kaolinite, and a combination of bentonite wi...

Ver documento
Adsorption of Rhodococcus Strain GIN-1 (NCIMB 40340) on Titanium Dioxide and Coal Fly Ash Particles

Rhodococcus strain GIN-1 (NCIMB 40340) can be used to enrich and isolate a titanium-rich fraction from coal fly ash. The gram-positive bacterium was isolated by its ability to adhere strongly and rapidly to suspended particles of pure titanium dioxide or coal fly ash. Adsorption ...

Ver documento
1 / 5