Multichip systems trade-off analysis tool

This article discusses the conceptual/specification phase of multichip system design. The automation of conceptual design practices will decrease design and manufacturing risks by allowing system designers to view the entire performance design space early in the design cycle prior to the initiation of traditional physical design activities.This article describes a software tool that performs interdisciplinary trade-off analysis and partitioning for multichip systems including multichip modules (MCMs) and traditional assembly approaches. The tool concurrently computes physical, electrical, thermal, reliability, testability, and cost performance metrics for multichip systems. This tool allows a large fraction of possible design, technology, material, test, and manufacturing approaches to be explored before decisions are made and resources committed.An example set of trade-off results are presented which examine the trade-off between peripheral I/O format die and area array I/O format die in an MCM, as a function of partitioning a fixed functionality into a variable number of die.Visiting researcher at MCC from Eastman Kodak Company.     

Resistive Power in CMOS Circuits

Interconnect resistance dissipates a portion of the total transient power in CMOS circuits. Conduction losses increase with larger interconnect resistance. It is shown in this paper that these losses do not add to the total power dissipation of a CMOS circuit through I ² R losses. Interconnect resistance can, however, increase the short-circuit power of both the driver and load gates.     

Preparation of membranes based on high-density polyethylene graft copolymers for phosphate anion removal

This work was undertaken to synthesize graft copolymers that possess functional groups via the radiation-induced grafting of acrylamide onto a high-density polyethylene (HDPE) substrate. The optimum conditions suitable for radiation graft copolymerization were determined. In this regard, the effects of the solvent, the inhibitor concentration, the monomer concentration and the irradiation dose on the grafting yield were investigated. Selected properties of the prepared graft copolymers were investigated to elucidate the possibility of their practical use in the removal of metals and phosphate anions. The effects of different parameters that may affect the metal chelation process, such as pH, metal feed concentration and time of contact, were also studied. A chemically modified membrane loaded with Cu(II) was used for the removal of phosphate ions from aqueous solutions.     

Thermoelastic diffusion with memory-dependent derivative

The constitutive equations are derived for the thermoelastic diffusion in anisotropic and isotropic solids, in the context of a new generalized thermoelasticity theory with two time delays and kernel functions. The coupled thermoelastic diffusion and the Lord–Shulman theories result from the given theory as particular cases. For anisotropic solid, the reciprocity theorem is proved; the convolutional variational principle is given and the uniqueness theorem based on the variational principle is proved.     

Environmentally friendly road construction

Environmental pollution is a major problem in developing countries like Egypt. Reuse of waste polymers is considered an attractive solution for environmental white pollution and reducing of the costs of road pavement and maintenance. This research aims to prepare environmentally friendly hot mix asphalt (HMA) for paving using some industrial wastes as polypropylene and polyester fibers. The solid materials in the mix include normal and highly porous aggregates. 5% and 10% of waste polymers by weight of the asphalt were used to prepare special binders. The samples were tested for their physical properties, chemical properties, aging, scanning electron microscopy (SEM) and thermo-gravimetric analysis (TGA). The results revealed that the prepared HMA using 5% of waste polymer had high performance as compared to the ordinary one and the waste polymer could be used in road construction.     

A greener approach for full flax bleaching

Gray flax fabrics were treated in a single-stage process for desizing, scouring and bleaching using sodium perborate (SBP) as an environmentally safer bleaching agent. The SPB efficiently bleaches flax fabrics alone and without any catalysts. Different parameters affecting the treatment were studied to get maximum whiteness for the flax fabrics. The best results of bleaching were obtained with SPB concentration corresponding to 0.6 mol/L, pH value 10, temperature at 80°C and treatment time 3 h. The material/liquor ratio was kept at 1:30 and 2 g/L of the wetting agent was used throughout the experiment.     

Effects of electron beam irradiation on the structure–property behavior of blends based on low density polyethylene and styrene-ethylene-butylene-styrene-block copolymers

Low density polyethylene (LDPE) blends with different additives were exposed to various doses of electron beam irradiation. The additives used were styrene-ethylene-butylene-styrene-block copolymers (SEBS), styrene-ethylene-butylene-styrene-block copolymer grafted with maleic anhydride (SEBS-g-MA) and mineral compounds. The structure–property behavior of electron beam irradiated blends was characterized in terms of mechanical, thermal, and electrical resistivity properties. The results indicated that the unirradiated LDPE blends with the different compositions showed improved mechanical properties, thermal and volume resistivity properties than pure LDPE. However, the improvement in properties of unirradiated blends by using SEBS-g-MA was higher than using SEBS copolymer. Further improvement in the mechanical, thermal and electrical properties of the LDPE blends was achieved after electron beam irradiation. The limited oxygen index (LOI) data revealed that the LDPE/SEBS-g-MA/ATH blend was changed from combustible to self-extinguishing material after electron beam irradiation to a dose of 100 kGy. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Modification of cement with succinic anhydride‐based hyperbranched polyesteramide

Two hyperbranched polyesteramides (HYP₁ and HYP₂) were prepared by reacting succinic anhydride (ScAn) with both of diisopropanolamine (DiPA) and diethanolamine, respectively, via one‐pot polycondensation reaction. The prepared polymers were analyzed using gel permeation chromatography, infrared spectra, and 1HNMR. The resulting hydroxyl‐ended resins have been successfully applied as polymeric admixtures in two types of cements such as Ordinary Portland cement and Portland limestone cement. The water of consistency decreased by addition of the hyperbranched polymers in both types of cements. Better hydration was observed by incorporation of small amounts of polymers. The infrared spectra and scanning electron microscopy photos of Ordinary Portland cement and Portland limestone cement pastes premixed with HYP₁ and HYP₂ showed no effect on the chemical composition of the cement hydrates where only the morphology and the crystallinity of the formed hydrates were changed. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Two stage biodiesel and hydrogen production from molasses by oleaginous fungi and Clostridium acetobutylicum ATCC 824

In the present study biodiesel was produced by various fungal species isolated from Egypt using sugarcane molasses as substrate. In the first stage 6 oleaginous fungi, namely, Alternaria alternata, Cladosporium cladosporioides, Epicoccum nigrum, Fusarium oxysporum, Aspergillus parasiticus and Emericella nidulans var. lata were used for lipid production. Subsequent to fungal cultivation on sugarcane molasses the cultures were filtered and biodiesel was prepared by direct esterification of dry fungal biomass. Methyl esters of palmitic, stearic, linoleic and elaidic represented the major components while palmitoleic represented a minor component of biodiesel produced from tested oleaginous fungi. In the second stage, the spent medium of fungal culture was used as the fermentation medium for hydrogen production by Clostridium acetobutylicum ATCC 824. The maximum total H₂ yield was obtained with the spent medium of E. nigrum and A. alternata. The results presented in this study suggest a possibility of interlinking the biodiesel production technology by fungi with hydrogen production by C. acetobutylicum ATCC 824 to exploit the residual sugars in the spent media and therefore increase the economic feasibility of the biofuel production from molasses.