INTRODUCTION Air pollution in confined environments is a serious health problem, in that most people spend long periods indoors (in homes, offices, classrooms etc.). Some people (children, the elderly, heart disease patients, asthmatic or allergic subjects) are at greater risk because of their conditions of frailty. The growing use of air-conditioning systems in many public and private building...

Nanosized zeolite crystals (nanozeolites) with narrow particlesize distributions and sizes less than 100 nm have received much attention because of their great potential applications in catalysis and adsorption. The decrease in the crystal sizes results in high external surface areas, reduced diffusion path lengths, and more exposed active sites. For example, small Y-type zeolite crystals have ...

The ability of four steroids and three bile acids to promote the appearance of hyperplastic foci and hyperplastic nodules initiated by diethylnitrosamine (DEN) in the liver of male Fischer rats was tested and compared with that of the known promoter phénobarbital (PB, 0.05%) as a standard value. Two weeks after a single dose of 200 mg of DEN per kg, the animals were exposed to test chemicals f...

We present the result of an indirect search for high energy neutrinos from WIMP annihilation in the Sun and in the Earth using upward-going muon events at Super-Kamiokande. Datasets from SKI-SKIII (3109.6 days) were used for the analysis. We looked for excesses of neutrino signal from the Sun and the Earth as compared with the expected atmospheric neutrino background in three types of upward-go...

gram (Adriano, 1986; Davies, 1992; Forstner, 1995; Ma and Rao, 1997). Measurement of cation selectivity in soils provides important infor­ mation about the affinity and binding strength of a particular cation In many cases, much of the Pb in uncontaminated on soil surfaces. Gaines-Thomas (KGT) selectivity coefficients were determined for a variety of K/Ca and K/Pb ratios on an Oxisol and Ultiso...

In heterogeneous catalysis transition metal-containing zeolites, in particular copperexchanged zeolites, have been studied experimentally [1, 2] as well as theoretically. Zeolites have large surface areas and different active sites (Brønsted acid sites and transition metal centers) which play a significant role in catalysis. In order to study the catalytic oxidation of benzene to phenol using d...

A novel activated carbo-aluminosilicate material was prepared from oil shale by chemical activation. The chemicals used in the activation process were 95 wt% sulfuric and 5 wt% nitric acids. The produced material combines the sorption properties and the mechanical strength of both activated carbon and zeolite. An X-ray diffraction analysis shows the formation of zeolite Y, Na-X, and A-types, so...

In this research, the removal of lead from the aqueous solution was investigated using natural nontoxic zeolite (clinoptilolite) as a low-cost adsorbent in order to reduce human exposure to it. The clinoptilolite zeolite obtained from the Semnan area was characterized by X-ray diffraction pattern, FTIR spectroscopy and scanning electron microscopy (SEM). The central composite design (CCD) defin...

Renewable aromatics can be conveniently synthesized from furanics by introducing an intermediate hydrogenation step in the Diels-Alder (DA) aromatization route, to effectively block retro-DA activity. Aromatization of the hydrogenated DA adducts requires tandem catalysis, using a metal-based dehydrogenation catalyst and solid acid dehydration catalyst in toluene. Herein it is demonstrated that ...

The Friedel–Crafts acylation of 2-methoxynaphthalene was carried out in the liquid-phase batch conditions using Hmordenite, H-beta and H-Y zeolite as catalysts. All the catalysts showed 35–40% conversion in the temperature range of 100–150◦C. 1-Acyl-2-methoxynaphthalene was formed as the primary product. When acetyl chloride was used as the acylating agent, a higher yield of 6-acyl-2-methoxynap...