The electronic structure of BaFe2As2 doped with Co, Ni, and Cu has been studied by a variety of experimental and theoretical methods, but a clear picture of the dopant 3d states has not yet emerged. Herein we provide experimental evidence of the distribution of Co, Ni, and Cu 3d states in the valence band. We conclude that the Co and Ni 3d states provide additional free carriers to the Fermi le...

Anaerobic CO dehydrogenases catalyze the reversible oxidation of CO to CO2 at a complex Ni-, Fe-, and S-containing metal center called cluster C. We report crystal structures of CO dehydrogenase II from Carboxydothermus hydrogenoformans in three different states. In a reduced state, exogenous CO2 supplied in solution is bound and reductively activated by cluster C. In the intermediate structure...

An inactive, Ni-deficient form of carbon monoxide (CO) dehydrogenase [carbon-monoxide:(acceptor) oxidoreductase; EC 1.2.99.2], designated apo-CO dehydrogenase, accumulated in Rhodospirillum rubrum when cells were grown in the absence of Ni and treated with CO. In vivo, both CO dehydrogenase activity and hydrogenase activity increased several hundred fold upon addition of 2 microM NiCl2. Apo-CO ...

The electrical resistivity of Co/Ni and Cu/Ni superlattices exhibit resistivity oscillations as a function of superlattice period L, while Ag/Pd does not. Moreover, the resistivity of Co/Ni superlattices shows quantum size effects and a resistivity enhancement with L, as a function of total film thickness d . These results are consistent with a model which assumes d-electron localization in the...

In order to examine whether catalyst granular size was a factor for tar removal and syngas composition enhancement, three Ni/char catalysts with 90-100 mesh (Ni/SC), 50-60 mesh (Ni/MC), and 20-30 mesh (Ni/LC) size were prepared with a mechanical mixing method and tested in an updraft gasifier. Reforming parameters investigated were the reaction temperature (650-850C), the Ni loading (5-20% of ...

Administration of nickel carbonyl to rats inhibited RNA synthesis by a chromatin-RNA polymerase complex prepared from lysed hepatic nuclei. Rats were killed 6 hr after i.v. administration of Ni(CO)4 in LDSO dosage (2.2 mg Ni/100 g body weight). The rate of RNA synthesis by the chromatinRNA polymerase complex from Ni(CO)4-treated rats averaged 0.16 (S.E. = ±0.02, N = 18) ¿/mole cytidine tripho...

The genus Alyssum (Brassicaceae) contains Ni hyperaccumulators (50), many of which can achieve 30 g kg(-1) Ni in dry leaf. Some Alyssum hyperaccumulators are viable candidates for commercial Ni phytoremediation and phytomining technologies. It is not known whether these species secrete organic and/or amino acids into the rhizosphere to solubilize Ni, or can make use of such acids within the soi...