welders may suffer from welding fumes generated during the process if the ventilation systems are improperly applied. the objective of the present work was to study the mitigation of air pollutants at welding stations, using different ventilation scenarios. four air pollutants including iron oxide, respirable dust, ozone, and carbon monoxide were measured during four different ventilation scena...

the nanoparticles of ni–si mixed oxides were prepared by co-precipitation method using nickel nitrate; ni(no3)2 6h2o and tetraethylorthosilicate (teos). the products were characterized by x-ray diffraction (xrd), transmission electron microscopy (tem), and hydrogen temperature program reduction (h2-tpr). the results revealed that ni–si mixed oxides particles were obtained with average particle ...

A variety of metal nitrates were filled into the pores of an ordered mesoporous CMK-3 carbon matrix by solution-based impregnation. Thermal conversion of the metal nitrates into the respective metal oxides, and subsequent removal of the carbon matrix by thermal combustion, provides a versatile means to prepare mesoporous metal oxides (so-called nanocasting). This study aims to monitor the therm...

Manganese (Mn) oxides, which are generally considered biogenic in origin within natural systems, are the only oxidants of Cr(iii) under typical environmental conditions. Yet the influence of Mn biooxide mineral structural evolution on Cr(iii) oxidation under varying geochemical conditions is unknown. In this study we examined the role of light, organic carbon, pH, and the structure of biogenic ...

Carbon oxides such as carbon dioxide (CO2) and carbon trioxide (CO3) have long been known as important molecules in atmospheric and solid state chemical reactions. Although higher order carbon oxides have been theoretically predicted to be stable and also important, their detection has been difficult. Here, we report on the first spectroscopic detection of the cyclic (C2v) isomer of carbon tetr...

The reaction between aqueous Fe(II) and Fe(III) oxides is extremely complex, and can catalyze Fe(II)-Fe(III) electron transfer, exchange of Fe atoms between the aqueous and solid phases, mineral transformation, and contaminant reduction. Together, these processes represent a phenomenon referred to as Fe(II)-catalyzed Fe oxide recrystallization, which has been observed under controlled condition...

Transition metal oxides that mix electronic and ionic conductivity are essential active components of many electrochemical charge-storage devices, ranging from primary alkaline cells to more advanced rechargeable Li-ion batteries. In these devices, charge storage occurs via cation-insertion/deinsertion mechanisms in conjunction with the reduction/oxidation of metal sites in the oxide. Batteries...

In this article, we report a facile approach to enhance the electrochemical performance of Li-rich oxides with vulnerable phase stability. The Li-rich oxide nanoparticles were attached to the surface of graphene; the graphene surface acted as a matrix with high electronic conductivity that compensated for the low conductivity and enhanced the rate capability of the oxides. Our novel approach co...

Ordered nanoporous silicas containing various binary copper-manganese oxides were prepared as catalytic systems for effective carbon monoxide elimination. The carbon monoxide elimination efficiency was demonstrated as a function of the [Mn]/[Cu] ratio and reaction time. The prepared catalysts were characterized by Brunauer-Emmett-Teller (BET) method, small- and wide-angle X-ray diffraction (XRD...

Carbon dioxide (CO2) rich chlorine-bearing ices were exposed to energetic electrons in laboratory simulation experiments to investigate the formation of chlorine oxides (ClxOy) in the condensed phase on Mars. The radiolysis-induced synthesis of chlorine oxides (ClxOy) was complementarily monitored online and in situ via infrared spectroscopy (IR) and quadrupole mass spectrometry (QMS). Three di...