In recent decades, porous asphalt has been extended for surface drainage in various regions throughout the world. The permeability of porous asphalt has an important role in the performance of asphalt pavements in the rainy weather. The most remarkable problem related to the porous asphalt is its short service time. Considerable efforts have been made to enhance the mechanical properties of por...

A series of carboxyethylphosphonate hybrid materials has been prepared: Mn(II)(O3PCH2CH2COOH) *H2O (1), Mn(III)(OH)(O3PCH2CH2COOH)*H2O (2), Al3(III)(OH)3(O3PCH2CH2CO2)2 *3H2O (3) and Cr2(III)(OH)3(O3PCH2CH2CO2) *3H2O (4). Compounds 1 and 2 were synthesized from Mn(III)(CH3COO)3 *2H2O under hydrothermal, or refluxing treatments, respectively. The crystal structures of the manganese-bearing solid...

A method of fluorination assisted electrothermal vaporization inductively coupled plasma mass spectrometry (FETV-ICP-MS) was developed to directly determine the trace impurities in niobium pentaoxide solid powder in which a poly(tetrafluoroethylene) (PTFE) emulsion was used as fluorinating modifier to promote the vaporization of refractory elements from a graphite furnace and to avoid the forma...

The room-temperature crystal structures of six A(2)M(3+)M(5+)O(6) ordered perovskites have been determined from neutron and X-ray powder diffraction data. Ba(2)YNbO(6) adopts the aristotype high-symmetry cubic structure (space group Fm\overline 3m, Z = 4). The symmetries of the remaining five compounds were lowered by octahedral tilting distortions. Out-of-phase rotations of the octahedra about...

This research work studies the characteristics of wear and resistance composite powder coatings, deposited by supersonic flame jet (HVOF), which contain mixtures Ni-Cr-B-Si having different chromium concentrations—9.9%, 13.2%, 14%, 16%, 20%, at one same size particles content remaining elements. The coating 20% Cr does not B Si. Out each composite, coatings have been prepared without any prelim...

chromium (cr) is one of the elements presents in crust of the earth. due to its toxicity, chromium is considered as water contaminant that may disturb metabolic activity. in the present study, adsorption of dissolved chromium (vi) onto elaeagnus angustifolia fruit charcoal, jujube fruit charcoal and the standard granular activated carbon (gac) has been investigated and compared. the effect of c...

Improvement of Resistance of Structural Metal Ceramics of Fe-C-Mn-MoCr Type by Boron Nonmetalic Coatings I. Mitev Department of Machinery and Equipment Technical University of Gabrovo 4, H. Dimiter str. Bulgaria ______________________________________________________________________________________ Abstract: During the last years the development of powder metallurgy is connected with constant se...