The coherent anti-Stokes Raman spectroscopy (CARS) method has recently been used in the United States and Europe to probe several different types of propulsion systems for air vehicles. At NASA Langley Research Center in the United States, CARS has been used to simultaneously measure temperature and the mole fractions of N2, O2 and H2 in a supersonic combustor, representative of a scramjet engi...

FeFe hydrogenases are the most efficient H2 producing enzymes, but inactivation by O2 is an obstacle to using them in biotechnological devices. Here we combine electrochemistry, sitedirected mutagenesis, molecular dynamics and quantum chemical calculations to uncover the molecular mechanism of O2 diffusion within the enzyme and its reactions at the active site. We find that the partial reversib...

The effects of H2 gas treatment of an agricultural soil cultivated previously with a mixture of clover (Trifolium pratense) and alfalfa (Medicago sativa) on CO2 dynamics and microbial activity and composition were analyzed. The H2 emission rate of 250 nmol H2 g K1 soil h was similar to the upper limit of estimated H2 amounts emitted from N2 fixing nodules into the surrounding soil ([Dong, Z., L...

10 Abstract CexZr1-xO2 (x = 0.10, 0.16 and 0.33) nano11 crystalline powders were obtained by a two-step synthesis 12 technique and sintered by spark plasma sintering (SPS). As 13 consequence of the reduction of Ce to Ce species by 14 carbon in the graphite environment in SPS, phase assem15 blies including tetragonal, monoclinic and pyrochlore 16 phases were generated in the ceramics during the ...

Abstract. The operation principle of a commercially available solid electrolyte sensor was modified with respect to applications in flowing gaseous mixtures containing H2 and O2. For this purpose the generally applied coulometric or potentiometric operation mode was replaced by cyclic voltammetry. By varying the sensor temperature, electrode area and potential scan rate, the conditions for the ...

Artificial photosynthetic systems can store solar energy and chemically reduce CO2 We developed a hybrid water splitting-biosynthetic system based on a biocompatible Earth-abundant inorganic catalyst system to split water into molecular hydrogen and oxygen (H2 and O2) at low driving voltages. When grown in contact with these catalysts, Ralstonia eutropha consumed the produced H2 to synthesize b...

This study investigates the separation based on adsorption of the binary gas mixture of hydrogen withbiogas (gases: CO2, CH4, O2, N2) and inert gases (gases: He, Ne, and Ar) using single-walled ((7,7), (15,15),(29,29), (44,44), (58,58) and (73,73) SWBNNTs), double-walled ((11,11)@(15,15), (7,7)@(22,22) DWBNNTs)and triple walled ((8,8)@(11,11)@(15,15) and (7,7)@(15,15)@(22,22) ...

A mathematical model is presented to explain the regulation of nitrogenase electron allocation to N2 fixation (EAC) in legume nodules. The model is based on two assumptions: (a) that H2 inhibits N2 fixation in a competitive manner; and (b) that O2, H2, and N2 move into and out of nodules by diffusion and their movement is impeded by a diffusion barrier, the permeability of which is controlled t...

The oxidation behaviors of LiH under a high purity argon atmosphere, an argon atmosphere with some O2 and H2O impurities, and ambient air at both room and high temperatures, are investigated using a variety of analytical instruments including X-ray diffractometry, thermogravimetry, mass spectrometry, scanning electron microscopy, and specific surface area analysis. The oxidation behaviors of th...

Intramolecular hydrogen bonds (IHBs) play a central role in the molecular structure, chemical reactivity and interactions of biologically active molecules. Here, we study the IHBs of seven related o-carbonyl hydroquinones and one structurally-related aromatic lactone, some of which have shown anticancer and antioxidant activity. Experimental NMR data were correlated with theoretical calculation...