Because toxicities may differ for Cr(VI) compounds of varying solubility, some countries and organizations have promulgated different occupational exposure limits (OELs) for soluble and insoluble hexavalent chromium (Cr(VI)) compounds, and analytical methods are needed to determine these species in workplace air samples. To address this need, international standard methods ASTM D6832 and ISO 16...

The simultaneous combination of steady state isotopic transient kinetic analysis (SSITKA) with diffuse reflectance Fourier transform spectroscopy (DRIFTS) and mass spectrometric (MS) analysis was applied to study the oxidative carbonylation of methanol (MeOH) to dimethyl carbonate (DMC) on a CuY zeolite catalyst prepared by incipient-wetness impregnation of commercial zeolite NH(4)-Y. The inter...

Carbon dioxide interacts both with reactive nitrogen species and reactive oxygen species. In the presence of superoxide, NO reacts to form peroxynitrite that reacts with CO2 to give nitrosoperoxycarbonate. This compound rearranges to nitrocarbonate which is prone to further reactions. In an aqueous environment, the most probable reaction is hydrolysis producing carbonate and nitrate. Thus the n...

The reaction mechanism of CO oxidation on Au/TiO2 catalysts remains elusive. Here, we employ density functional theory calculations to gain an understanding of several important aspects of the system, including CO adsorption, the active oxygen species, catalyst deactivation, and the promoting effect of moisture on catalytic activity. Distinct from previous theoretical studies, which tend to add...

Both calcium-containing and noncalcium-containing phosphate binders can increase gastrointestinal calcium absorption. Previously, we observed that lanthanum carbonate administration to rats with renal failure is not associated with increased calciuria. Additionally, lanthanum carbonate treatment in dialysis patients has been associated with a less pronounced initial decrease in serum parathyroi...

Lithium ethylene dicarbonate (CH2OCO2Li)2 was chemically synthesized and its Fourier Transform Infrared (FTIR) spectrum was obtained and compared with that of surface films formed on Ni after cyclic voltammetry (CV) in 1.2M lithium hexafluorophosphate (LiPF6)/ ethylene carbonate (EC): ethyl methyl carbonate (EMC) (3:7, w/w) electrolyte and on metallic lithium cleaved in-situ in the same electro...

“Stickies” are tacky species, present in recycled paper and coated broke, derived from coating formulations, adhesives etc. They impact negatively on paper quality and cause web runnability problems by deposit build-up. To sustain recycling, stickies are controlled by adsorbing them onto minerals added to the recycled stock. We report isotherms for a fatty acid ester defoamer and an acrylic aci...

In this study we estimate sediment carbonate dissolution rates for sandy sea grass sediments on the Bahamas Bank using an inverse pore-water advection/diffusion/reaction model constrained by field observations. This model accounts for sea grass O2 input to these sediments, and also parameterizes pore-water advection through these permeable sediments as a nonlocal exchange process. The resulting...

In situ FT-IR spectroscopy was exploited to study the adsorption of CO2 and CO on commercially available yttria-stabilized ZrO2 (8 mol % Y, YSZ-8), Y2O3, and ZrO2. All three oxides were pretreated at high temperatures (1173 K) in air, which leads to effective dehydroxylation of pure ZrO2. Both Y2O3 and YSZ-8 show a much higher reactivity toward CO and CO2 adsorption than ZrO2 because of more fa...

In the present work we explore via first-principles simulations whether the ligand/cluster/support catalytic complex generated by CO oxidation over silver trimers deposited on the regular MgO(100) surface - i.e. a Ag3/carbonate or Ag3(CO3)/MgO(100) species - can be used as a catalyst in a different reaction: the selective oxidation of NO to NO2 (or NOox). The Ag3(CO3)/MgO(100) complex is first ...