Tris(trimethyl-stannyl,-germyl, -sijyl)borates

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A Geological Appraisal of Slope Instability and Proposed Remedial Measures at Kaliasaur Slide on National Highway, Garwal Himalaya

For over six decades Kaliasaur landslide (Lat. 30° 14\u27 30 N, Long. 78° 55\u27 50 E) is a nightmare on the Hardwar-Badrinath road in the Garhwal Himalaya. Located on a sharp bend on the left bank of river Alaknanda, it has emerged as a multi-tier repetitive major landslide, retrogressive in nature. Both surficial and deep seated movements have been monitored. The sliding in the upper layers have been predominantly in the colluvium but where interfaces of quartzite and shale participates, the sliding surfaces have been better defined and discrete. In the present paper, the authors have highlighted the geological, geomorphological and morphometric parameters to diagnose the factors responsible for instability of slope and the magnitude of the problems involved. A scheme of remedial measures which .include modification of existing drainage pattern, timber piling for stitching of debris cover on to the slope, construction of retaining walls and putting back the vegetation on the slope are recommended for control of the landslide

Circuit simplification by adopting flotation columns.

Pilot scale studics on the beneficiation of low-grade fluorspar and copper-lead-zinc ore were investigated using flotation columns. Acidspar concentrates suitable for HF production can be produced by adopting two-stage column cleaning in place of multi-stage cleaning by conventional flotation cells. A three-column canfiguration in the place of four-stage cleaning in acidspar circuit and four in metspar circuit was suggested. Similarly, it was demonstrated that a single stage cleaning by flotation column was found to be sufficient in the plnce of two-stage cleaning by conventional flotation cells to obtain bulk concentrates of Cu-Pb-Zn

Microstructural Study of Galvanized coatings formed in Pure as well as Commercial Grade Zn Baths

The hot dip galvanizing is a complex metallurgical process wherein a steel strip is immersed in a zinc alloy bath normally between 450 and 480°C. The protective coating that is formed consists of a series of intermetallic Fe—Zn compound layers, which have been identified as gamma (r), delta (6), zeta (4) and an outer eta (T) layer, highly rich in Zn. There is no apparent delay in the formation of 4 or 6 phases (less than 5 s reaction time) in pure Zn bath as well as the commercial grade Zn bath. The gamma (I') phase is formed after an incubation time of 30 s at a bath temperature of 470°C in the pure Zn bath. The forma-tion and growth of F phase, however, is delayed in the commercial grade Zn bath. The last morphological feature is the formation of a second 4 layer at the 4/6 interface in reaction time above 30 s. Presence of Pb in the comme-rcial grade Zn bath seems to increase the overall coating thickness. Commercial grade Zn, however, enhances the dross formation in the bath and detoriates the quality of the coating. Presence of transverse cracks as well as entrapment of dross particles in these coatings is attr-ibuted to the less compact coatings that are formed in the commercial grade Zn baths. The present investigation is an effort to have a better understanding of the kinetics of growth and morphology of the coatings during the galva-nizing process in the pure as well as commercial grade Zn baths

Korean Character Recognition Using Neural Networks

We present a neural-network approach for recognizing printed Korean characters. Our approach is based on a variant of the back-propagation algorithm. The results indicate that by transforming the character data into Hough space, we can achieve excellent recognition

Microwave dielectric relaxation & polarization study of binary mixture of methylethylketone with nitrobenzene

Present paper reveals detailed study of dielectric relaxation and dielectric polarization and physicochemical study of binary polar-polar liquid mixture i.e. dielectric constant, relaxation time, viscosity, density of methylethylketone (MEK) with nitrobenzene (NB) at 303 K. The measured dielectric and physicochemical parameters employed to acquire additional derived properties like Bruggeman factor, molar refraction and excess properties like static dielectric constant, excess inverse relaxation time, excess molar volume, excess viscosity, excess molar refraction, Gibbs free energy, and enthalpy of activation. The variation of this parameters with composition of these quantities has been used to explain the type, strength and nature of intermolecular interactions between MEK+NB binary mixture. Attained results authenticate that there are strong hydrogen-bond interactions between unlike molecules of different groups of MEK+NB mixtures and that 1:1 complexes are produced and strength of intermolecular interaction rises with rise in concentration of MEK.               KEY WORDS: Bruggeman factor, Excess inverse relaxation time, Dielectric polarization Bull. Chem. Soc. Ethiop. 2019, 33(2), 349-358.DOI: https://dx.doi.org/10.4314/bcse.v33i2.1