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Alkaline fusion processed waste glass was re-used as a supplementary Si-source to improve the mechanical properties of Egyptian metakaolin-based geopolymers. Different alkaline silicate solutions having different Si[O.sub.2]/[Na.sub.2]O ratios were almost entirely prepared from waste glass fusion filtrates. Size of metakaolin and waste glass particles as well as early age curing temperature were governor factors on compressive strength. Structures were examined using XRD and FT-IR techniques, while microstructure was examined using SEM. Geopolymerization of as-received MK, at ambient temperature, recorded 28day compressive strength of 35.36 MPa. Mechanical properties were improved via four consequential stages by lowering MK particle size to less than 38 pm, loading of 3% undissolved waste glass, loading of 7% fused waste glass at Si[O.sub.2]/[Na.sub.2]O of 1.55, and early age curing at 40[degrees]C recording 80.75, 82.36, 93.08 and 97.41 MPa, respectively. Geopolymerization reactions were evaluated spectroscopically. FT-IRS were deconvoluted by Gaussian equations. Quality evaluations of products were examined using SEM whence homogeneity, continuity and amount of un-reacted species. Na-geopolymers were observed along all studies temperatures with quality favorability to early age curing at 40[degrees]C. Keywords: Fusion processing Waste glass Metakaolin Geopolymer Mechanical properties Microstructure-final, GRAPHICAL ABSTRACT 1. Introduction Municipal waste streams across the world generate millions of tons of glass every year. During 2012 Egypt generates 21 million tons of municipal solid wastes. Waste [...]

A new approach is developed for conducting a cost-duration analysis (trade-off study) for a project denned with a CPM/PERT activity network. The approach utilizes a new graph theory concept, proper oriented cut-set (POCS). It also uses the cut network, a dual-type network defined in this paper for any planar activity network. The cut network implicitly enumerates all POCS's of an original network. The cost-duration problem defined for the original activity network is transformed into a minimum-cost flow problem for the cut network. This approach to cost-duration analysis, developed here for a planar network and linear activity cost-duration relations, is optimal, conceptually direct, and has potential for application to more general cost-functions.