A New Modification of Nonlinear Conjugate Gradient Coefficients with Global Convergence Properties

Conjugate gradient method has been enormously used to solve large scale unconstrained optimization problems due to the number of iteration, memory, CPU time, and convergence property, in this paper we find a new class of nonlinear conjugate gradient coefficient with global convergence properties proved by exact line search. The numerical results for our new βK give a good result when it compared with well known formulas.

Comparative Characterization Study of Malaysian Sand as Proppant

This paper presents a review on published literature and experimental works on local sands for possible use as proppant, specifically those from Terengganu coastal area. This includes examination on characteristics of sand samples and selection of experiments for proppant testing. Sand samples from identified areas were tested according to particle size distribution, density, roundness and sphericity, turbidity and mineralogy. Results from sand samples were compared against proppant specifications set by API RP 56 and selected commercial proppants. The present study found that the size distribution, sphericity, turbidity and bulk density of Terengganu sands are at par with some of commercial proppants. Nevertheless, Terengganu sand samples do not completely surpass the required roundness for use as proppant.