Showing papers by "Thapar University published in 1997"

Multiobjective symmetric duality with invexity

Abstract: VOL. 56 (1997) [25-36]MULTIOBJECTIVE SYMMETRIC DUALITY WITH INVEXITYT.R. GULATI, I. HUSAIN AND A. AHMEDUsual duality results are proved for Wolfe and Mond-Weir type multiobjective sym-metric dual problems without nonnegativity constraints under invexity/generalisedinvexity assumptions. Moreover, assuming the kernel function to be skew symmet-ric, the multiobjective problems are exhibited to be self duals.

Symmetric duality for nondifferentiable minimax mixed integer programming problems # #The authors wish to thank a referee for his valuable suggestions which have improved the presentation of this paper. The third author is also thankful to University Grants Commission, India for providing financial support$ef:

Abstract: Two distinct pairs of nondifferentiable minimax mixed integer mathematical programming problems are formulated and symmetric duality theorems are established. Self duality for these pairs has also been discussed

Symmetric Duality with Invexity in Static and Continuous Fractional Programming

Abstract: The usual duality results are established for static symmetric dual fractional programming problems without nonnegativity constraints using the notion of invexity which has allowed weakening various types of convexity assumptions for mathematical programming problems extensively studied in the literature. These results are also extended to their continuous analogous as dynamic generalizations

Bamboo borer dust as a rich source of glucose-1-phosphate

Abstract: Chemical characterization of bamboo borer dust (BBD) indicated that it contained 2.5 ±0.5% of an organic entity that was a watersoluble, acid-labile phosphate, nonreducing sugar with a retention period of 5.2 min on a sugar pack column during high pressure liquid chromatography (HPLC). It was subsequently identified and confirmed as glucose-1-phosphate (G-l-P) from its response to phosphoglucomutase and glucose-6-phosphatase treatment. Although the presence of G-l-P in such a large quantity in BBD is inexplicable, it provides a rare and rich source of G-l-P, making it a potential starting material for its isolation in pure state.

Formation and undercooling of droplets in the primary phase of Ag-Ge alloys

Abstract: The formation of micro-sized droplets in the matrix of the primary phase of Ag–Ge alloys and their undercooling behaviour were investigated. Thermal cycling consisted in equilibration of hypoeutectic alloys near the eutectic temperature in the two-phase liquid–solid region followed by up-quenching of alloys at 30–50°C above the eutectic temperature and their subsequent slow cooling. A wide size range of droplets was generated in the matrix of the silver-rich phase by repeated thermal cycling of the alloy. During slow cooling, droplets of silver-rich liquid exhibited a maximum undercooling of 81°C below the eutectic temperature. Examination of the solidification structure of the undercooled alloys, by X-ray diffraction, polarized light microscopy and electron probe micro analysis techniques, indicated the presence of a metastable phase. The mechanism of formation of droplets and the nature of non-equilibrium solidification of the undercooled melt of silver–germanium alloys, are discussed.