In the exploratory study presented in this paper, an attempt was made to develop different mixtures of ultrahigh performance concrete (UHPC) using various locally available natural and industrial waste materials as partial replacements of silica fume and sand. Materials such as natural pozzolana (NP), fly ash (FA), limestone powder (LSP), cement kiln dust (CKD), and pulverized steel slag (PSS),...

al., 2002; Gallagher and Koch, 2003). It is based on slow injection of stabilizing materials at the up-gradient edge Passive site stabilization is a new technology proposed for nondisof a site, with subsequent delivery of the stabilizer to ruptive mitigation of liquefaction risk at developed sites susceptible to liquefaction. This technology is based on the concept of slow injecthe target locat...

AIMS To develop a job-exposure matrix (JEM) from personal and static respirable crystalline silica (RCS) measurements in UK industrial silica sand workers. METHODS A total of 2429 personal and 583 static RCS dust samples were collected using cyclone samplers at seven UK quarries between 1978 and 2000. These data were combined, and analysis of variance using general linear models was used to e...

This study examines the suitability of natural silica sand as a low-cost adsorbent for the removal of ammoniacal nitrogen and heavy metals, particularly iron and zinc, from semi-aerobic stabilized landfill leachate. Leachate samples were collected from the Pulau Burung landfill site (PBLS) in Penang, Malaysia. The above-mentioned contaminants are highlighted in this study because of their unsaf...

The vertical migration of N. carpocapsae infective juveniles applied to the soil surface or introduced 14 cm below the soil surface was studied in four different soil types (pure silica sand, coarse sandy loam, silty clay loam, and clay). The percentage of juveniles able to migrate and infect wax moth pupae placed in the soil decreased as the percentage of clay and silt increased. Most nematode...

Thymus serpyllum (creeping thyme) is a newly introduced medicinal and aromatic plant in Egypt. It was grown hydroponically for this study. The goal to assess the effect of three sandponic media (sand, silica, sand with silica) foliar spraying fulvic acid (without with) on growth, herbage yield, essential oil yield. experiment designed as split plot. main plots involved spraying, while subplots ...

abstract self compacting concrete (scc) is a new construction material in the world. the aim of this research is to construct self compacting concrete with high compressive strength using combination of nano silica and micro silica. for this purpose, nano silica, micro silica, portland cement type 2, superplasticizer (sp), and gravel and sand have been used. three different groups of samples wi...

Alumina or silica gel are used as catalysts for a solvent-free oxidation of benzoins to the corresponding benzils. These catalysts are easily recovered after completion of the reactions, which are carried out either by heating in a sand bath or using microwave irradiation. Comparison of the results obtained with both catalysts indicates that all the reactants examined were oxidized faster on al...

Silica sand is widely used in the transformation industry. For instance, it is used in the making of glass, silicates, paints, glass-ceramics and ceramics. Traditionally, glass and ceramic materials have been manufactured using high-purity silica and minerals taken from ore on the surface of the earth. However, during recent decades, the manufacture of household and industrial products has incr...