CsMBi<sub>3</sub>Te<sub>6</sub> and CsM<sub>2</sub>Bi<sub>3</sub>Te<sub>7</sub> (M = Pb, Sn): New Thermoelectric Compounds with Low-Dimensional StructuresKuei‐Fang Hsu, Duck Young Chung, Sangeeta Lal et al.|Journal of the American Chemical Society|2002 The new materials CsPbBi(3)Te(6) and CsPb(2)Bi(3)Te(7) were discovered through reactions of CsBi(4)Te(6) with PbTe, whereas the isostructural materials CsSnBi(3)Te(6) and CsSn(2)Bi(3)Te(7) were discovered through corresponding reactions with SnTe. The compounds can also be prepared from stoichiometric mixtures of Cs(2)Te, Pb (Sn), Bi, and Te. The crystal structures show a layered architecture of NaCl-type slabs alternating with layers of Cs atoms. This group of compounds offers a new quaternary system, Cs-M-Bi-Te (M = Pb and Sn), available for thermoelectric investigations, including fine-tuning of compositions and doping.
In vitro degradation of keratin by two species of Bacillus.Sangeeta Lal, Rarn C. Rajak, S. K. Hasija|The Journal of General and Applied Microbiology|1999 The ability of two species of Bacillus to degrade child's scalp hair, cow horn, cow hooves, and human nails in vitro under static conditions was studied by the determination of soluble sulphhydryl compounds as cysteine, disulphides as cystine, and release of extracellular keratinase along with changes in alkalinity of the culture filtrate. Child's scalp hair was found to be the most favored keratin substrate for Bacillus spp.