NOPR Collection:

Analysis of abrasive wear behaviour of RM filled LLD PE

Sat, 01 Apr 2000 00:00:00 GMT

Title: Analysis of abrasive wear behaviour of RM filled LLD PE Authors: Chand, Navin; Hashmi, S A R Abstract: Effect of addition of red mud (RM) particles on abrasive wear resistance of linear low density polyethylene (LLDPE) has been investigated using different wt% of RM particles incorporated in LLDPE and conducting two body abrasion tests on these samples. Worn surfaces are observed by using scanning electron microscope. Two stage wear loss behaviour has been observed for the RM filled LLDPE materials and found to be unique and different from the linearly increasing trend observed in case of unfilled LLDPE. Initially, wear loss is higher in filled LLDPE as compared to unfilled LLDPE. In the second stage after 20 m sliding distance, RM filled LLDPE shows increased wear resistance and wear loss becomes constant due to presence of a large number of fractured RM particles in the filled samples. Page(s): 103-105

Band gap of vacuum evaporated CdS thin films

Sat, 01 Apr 2000 00:00:00 GMT

Title: Band gap of vacuum evaporated CdS thin films Authors: Singh, Virendra; Singh, Beer Pal; Kumar, Vinod; Sharma, T P; Tyagi, R C Abstract: Thin films of cadmium sulphide (CdS) have been deposited in a low atmosphere of H₂S obtained by thermal decomposition of thiourea inside the vacuum chamber. The substrate is kept at an elevated temperature to eject any sulphur atoms deposited due to thermal decomposition of CdS during evaporation. The cadmium ions would promptly recombine with the H₂S to give better stoichiometry of the films. This results in better growth of films which are more uniform, more adherent, pin holes free and have better crystallity as have been inferred by the sharpness of the absorption spectra. Such films are inherently better suited for device fabrication. Page(s): 100-102

Studies on limestone-substituted alumina cement

Sat, 01 Apr 2000 00:00:00 GMT

Title: Studies on limestone-substituted alumina cement Authors: Darweesh, Hassan H M Abstract: The effect of substitution of alumina cement (50% Al₂O₃) by limestone up to 25% as well as its fineness on the physico-mechanical properties of the hardened cement pastes is reported. The results revealed that the replacement of alumina cement by limestone slightly decreases the water of consistency and the setting times (initial and final) . The bound water content increases with the curing time and the fineness of limestone. The total porosity decreases, and accordingly the compressive strength improves with the content and fineness of limestone. Hence, the limestone has a little accelerating action on the hydration process of the alumina cement but acts only as a filler reducing the porosity due to its compact structure. Therefore, the compressive strength of the hardened cement pastes is enhanced. The addition of finely ground limestone filler only up to 15% gives better results on strength. The XRD and DTA analyses of samples cured up to 28 days show that the addition of higher amounts of limestone filler to the aluminous cement tends to decrease the conversion reaction due to the partial carbonation of C₃AH₆. Page(s): 94-99

ZnO/UV Mediated photocatalytic degradation of Acid Green 16, a commonly used leather dye

Sat, 01 Apr 2000 00:00:00 GMT

Title: ZnO/UV Mediated photocatalytic degradation of Acid Green 16, a commonly used leather dye Authors: Sakthivel, S; Neppolian, B; Arabindoo, Banumathi; Palanichamy, M; Murugesan, V Abstract: The photocatalytic degradation of Acid Green 16 has been investigated in the presence of an aqueous suspension of ZnO irradiated with near UV light (254 nm). The influences of irradiation time, initial concentration of the dye, catalyst loading, light intensity, pH, particle size, presence of oxygen, nitrogen, hydrogen peroxide, FeCl₃ and Fenton's reagent on the degradation efficiency were systematically studied. The decolourisation and extent of degradation of the dye were determined by UV-Vis spectroscopy and COD reflux methods respectively. Complete mineralisation was confirmed by COD analysis as well as high performance liquid chromatography (HPLC). Page(s): 87-93