Efficiency Of Carbon Monoxide Research Articles

Combined effect of carbon monoxide mixed with carbon dioxide in air on the mortality of stored-grain insects

A study to determine the effect of carbon monoxide (CO) mixed with carbon dioxide (CO 2) in air on controlling stored-grain insects was conducted in the laboratory. Within modified airtight gas exposure units containing wheat at 15% moisture content wet basis (w.b.), mixed-age adults of rusty grain beetle, Cryptolestes ferrugineus (Stephens), red flour beetle, Tribolium castaneum (Herbst), and granary weevil, Sitophilus granarius (L.) were exposed for 48, 96, 144 or 192 h to three types of gas mixtures in air, 5% CO, or 30% CO 2, or 5% CO + 30% CO 2 at 20 °C and 30 °C, the balance of the gas being air in each case. Carbon monoxide alone had no effect on the mortality of adults of the three insect species. For C. ferrugineus, there was no difference in mortality between by CO 2 alone and the CO 2 + CO mixture at either temperature for all exposures. However, both T. castaneum and S. granarius had higher mortality in the CO 2 + CO mixture than the CO 2 alone at both temperatures. Moreover, S. granarius was more susceptible to CO 2 + CO mixture than T. castaneum. These results suggest that for certain species, CO could be used to increase the efficiency of CO 2, especially at high temperatures.

Catalysis of oxidation of carbon monoxide on supported gold nanoparticle

Gold used to be considered to have no catalytic activity. In the 1980s, however, Masatake Haruta found that nano-sized gold particles supported by metal oxides can catalyze the oxidation of carbon monoxide. This work examines the oxidation of carbon monoxide (CO) and the adsorption/desorption behaviors on nano-sized gold catalyst at room temperature by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). Carbonate, bicarbonate and carboxylate were observed. The effects of various factors (relative humidity, CO gas concentration, and total surface area) on the CO conversion efficiency were studied using the response surface designs in the Experiment Design Method. The results indicate that the conversion efficiency of CO was high when the ratio of CO and O 2 was close to 1:1. The gas concentration is the most important factor, followed by the weight of gold catalyst, followed by relative humidity. An appropriate humidity enhances the catalytic reaction in the long-term.

Variability of the apparent quantum efficiency of CO photoproduction in the Gulf of Maine and Northwest Atlantic

The photochemical oxidation of colored, dissolved organic matter (CDOM) is important for carbon cycling in the ocean. This oxidation process produces a number of products, including carbon monoxide (CO). While the photochemical production efficiency of CO (apparent quantum yield, AQY, defined in terms of CDOM absorbance) has been reported to be similar for many water types, a full evaluation of the observed natural variability in CO AQY requires additional study. Here we use a polychromatic irradiation system to determine twenty AQY spectra at sea on fresh samples ranging from the near coastal waters of the Gulf of Maine to the offshore waters of the Northwest Atlantic. Despite the geographic variability of these marine samples the AQY of CO production in the Gulf of Maine and Northwest Atlantic exhibited only a small degree of variability, none of which was not correlated with measured environmental parameters. Consequently, a single aggregate AQY spectrum ϕ λ = e (−(9.134+0.0425( λ−290)))+ e(−(11.316+0.0142( λ−290))) was found to adequately represent the entire data set. Significantly, the accuracy of an AQY spectrum determined using this multispectral/statistical technique was confirmed with data obtained from a monochromatic irradiation technique on a single open ocean sample. Taken together, the AQY spectra determined in this study were similar in magnitude and shape to those previously published for marine samples and, overall, were somewhat lower than those previously reported for freshwater studies.

A kind of new pyrochlore compounds with catalytic activity for the oxidation reaction of carbon monoxide and propylene

A series of new compounds with a formula RE2M2/3Nb4/3O7 (RE = Nd, Sm, Eu; M = Cu, Co, Zn) have been synthesized by a wet chemical method and the lattice parameters of the compounds have also been determined. The new compounds possess a pyrochlore structure and belong to hexagonal system. Most of the compounds have a certain catalytic activity for the oxidation reaction of carbon monoxide and propylene. The conversion efficiency of carbon monoxide and propylene on the surface of some compounds can be close to 100% at near 450°C. The compounds are insulator and the resistibility also is larger than 105 ohm · cm even if at 500°C. The compounds are a new kind of oxidation catalysts. The catalytic oxidation process of carbon monoxide and propylene on the surface of the compounds involves the oxidation-reduction of the cations in the compound and the catalytic process is a co-catalytic one. The effects of various metal cations in the compounds on the catalytic activity for the oxidation of carbon monoxide and propylene have been discussed.

Saturated gain due to vibrational–rotational transitions of the CO molecule

A theoretical investigation is made of the effect of gain saturation of short (1 nsec to 2 μsec) multifrequency light pulses in an active medium, in the case of cascaded transitions for the specific case of carbon monoxide. The saturation energy is determined and the gain is optimized with respect to a number of parameters. The efficiency of carbon monoxide as a medium for amplifying light pulses of 0.01-1μsec duration is found. An investigation is made of the evolution of the shape of a multifrequency signal as it propagates in an amplifier. Analytical expressions for estimating the parameters of a saturated pulse are obtained.