NOPR Collection:

Study of compositional and diffusion effect in Cd_xZn_1-xS sintered films

Fri, 01 Aug 1997 00:00:00 GMT

Title: Study of compositional and diffusion effect in Cd_xZn_1-xS sintered films Authors: Singh, V; Kumar, Vipin Abstract: H-VI Semiconductors are of great importance due to their applications in various electro-optic devices. CdS is a suitable window material for CdS/CdTe and CdS/C_u2S heterojunction solar cells. ZnS with band gap 3.54 eV can be substituted into CdS to increase the band gap of window material. The use of Cd_xZn_1-xS in place of Cd permits a greater open circuit voltage. On preparation of the sintered film of Cd_XZn_1-XS, the problem of diffusion arises, which disturbs the stoichiometry of the film. Here, methods have been suggested to preserve stoichiometry and minimize the diffusion problem in preparation of sintered films. Page(s): 163-165

Effect of heat treatment on the infrared absorption spectra of strontium-sodium-borosilicate glass

Fri, 01 Aug 1997 00:00:00 GMT

Title: Effect of heat treatment on the infrared absorption spectra of strontium-sodium-borosilicate glass Authors: Khalil, Elsayed Moustafa Ahmed; Aouf, Mona Abstract: Infrared absorption spectra of the prepared strontium-sodium-borosilicate glass (SiO₂ 80%-Na₂O 12.5%-B₂O₃ 5%-SrO 2.5%) are studied in the frequency range 200-4000 cm^-1, where strontium oxide was introduced on partial replacement of soda in sodium-borosilicate glass, to show the effect of divalent metal oxide introduced on the structural units SiO₄, BO₄, and BO₃ within the network structure of strontium-sodium-borosilicate glass, in the temperature range 27-800°C. The deformation of SiO₄ tetrahedra is investigated by using the baseline method, the temperature dependence of the relative integrated intensity, the relaxation time, and rotational energy barrier of this glass proved that the glassy phase is transformed to crystalline phase at 500°C. A slight shift occurs in the strongest bands of SiO₄ tetrahedra to higher frequencies, with temperature increase, which indicates an increase in the force constants between the components of the glass network structure. The increase of the absorbance in the temperature range 600-800°C indicates strengthening of the SiO₄ bonds. Page(s): 155-162

Optimization studies on limestone beneficiation

Fri, 01 Aug 1997 00:00:00 GMT

Title: Optimization studies on limestone beneficiation Authors: Rao, Sanyasi; Narayana, B V; Subramanian, S Abstract: Limestone rejects from Bagalkot mines have been beneficiated by froth flotation with a view to reducing the magnesia content. In order to ascertain the effect of the main parameters such as sodium oleate concentration, sodium silicate concentration and pH on the MgO content, statistically designed experiments have been performed. The results indicate that under the optimum conditions arrived at limestone rejects could be beneficiated to produce a concentrate with magnesia content meeting the specifications for cement manufacture. Page(s): 139-144

Coco-yam and water-yam starches: As alternative dual purpose polymer ingredients.

Fri, 01 Aug 1997 00:00:00 GMT

Title: Coco-yam and water-yam starches: As alternative dual purpose polymer ingredients. Authors: O-Ogbobe; Okeke, C N; Otashu, M Abstract: Increased elastic modulus and ultimate stress of low density polyethylene has been achieved by incorporating coco-yam, water-yam and guinea-com starches into low density polyethylene using a standard hot-melt compounding technique. Some mechanical properties of compression moulded dumb bell shaped films of low density polyethylene containing up to a maximum of 20 wt % of each starch is reported. Evidence is offered using IR spectroscopy linking the degradation of the low density polyethylene/starch composites in compost to an initial break down of the starch by micro-organism in the soil probably followed by diffusion of unsaturated lipids from the compost into the porous polymer which then leads to degradation by auto-oxidation. Page(s): 134-138

NOPR Collection:

Study of compositional and diffusion effect in CdxZn1-xS sintered films

Effect of heat treatment on the infrared absorption spectra of strontium-sodium-borosilicate glass

Optimization studies on limestone beneficiation

Coco-yam and water-yam starches: As alternative dual purpose polymer ingredients.

Study of compositional and diffusion effect in Cd_xZn_1-xS sintered films