Method for a Parallel Solution of a Combined Economic Emission Dispatch Problem

The power system simulation software tools are traditionally designed for serial codes and optimized using single-processor computers. They are inadequate in terms of computational efficiency and execution time for the ever-increasing complexity of the power grid. Due to the above-mentioned sequential computing demerits, this paper used MATLAB data parallelism message passing interface software to execute the Lagrange's and Particle Swarm Optimization (PSO) algorithms in parallel with multiple processor units with different and large data sets for the solution of the Combined Economic Emission Dispatch (CEED) problem. The two important advantages of using parallel computing approach to solve the power system economic dispatch problem are 1) to increase the efficiency (solution quality) and 2) to reduce the execution time (speed-up) of the parallelization process for the CEED problem solution. The comparison between the Lagrange's and PSO data-parallel solution quality and execution time is presented for the CEED problem for Institute of Electrical and Electronic Engineers (IEEE) 30 bus and IEEE 118 bus systems. The paper contributes to the on-line real-time market analyses of the deregulated power system, which need improved solution quality and a fast computation process to solve the power system energy management (CEED) problems for proper discussion and decision making at the control center level.     

Crystallization‐induced shrinkage,crystalline, and thermomechanical properties of in situ polymerized cyclic butylene terephthalate

The polymerization and crystallization of cyclic butylene terephthalate oligomers (CBT) were followed by fiber Bragg grating (FBG) and normal force measurements under isothermal conditions at T = 170 and 190°C, respectively. It was found that the FBG and normal force sense only the crystallization‐induced shrinkage. The course of the FBG signal and the normal force as a function of time suggested that crystallization of the polymerized CBT (pCBT) occurs in two steps. The primary crystallization‐induced shrinkage is several hundreds by contrast to the secondary one showing several tens in ppm/min unit according to the FBG results. The two‐step crystallization was confirmed by normal force measurements. The crystallinity and crystalline structure of the pCBTs were studied by differential scanning calorimetry and wide‐angle X‐ray scattering. It was found that the crystallinity and the crystalline parameters slightly differ for the pCBTs formed at T = 170 and 190°C, respectively. The pCBT produced at T = 190°C had slightly higher crystallinity and more perfect crystals than the pCBT formed at T = 170°C. The reliability of the FBG sensing was checked by thermomechanical analysis (TMA). A fair agreement was established between the thermal contraction and thermal expansion measured by FBG and TMA, respectively. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci 2008     

MOLECULAR STRUCTURE AND REACTIVITY OF PETROLEUM RESIDUA

ABSTRACT

The chloromethylation of petroleum residua — especially the asphaltenea — is described from the chemical and kinetic aspects. Properties of the products are discussed in detail.     

Effect of the Structure of Cellulose Diacetate—Acetone Solutions on the Properties of Ultrafiltration Membranes

Addition of more than 0.2 wt.% NaHCO₃ to CDA—acetone solution causes aggregation of gel particles and decreases the number of through pores and output of the membrane. A modified method of dry-wet spinning of membranes whose pore structure ensures effective separation of protein from curd whey is proposed.     

Compatibilizing effect of maleated polypropylene on the mechanical properties and morphology of injection molded polyamide 6/polypropylene/organoclay nanocomposites

Polyamide 6/polypropylene (PA6/PP=70/30 parts) blends containing 4 phr (parts per hundred resin) of organophilic modified montmorillonite (organoclay) were prepared using twin screw extruder followed by injection molding. Maleated polypropylene (MAH-g-PP) was used to compatibilize the blend system. The mechanical properties of PA6/PP nanocomposites were studied through tensile and flexural tests. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to assess the fracture surface morphology and the dispersion of the organoclay, respectively. X-ray diffraction (XRD) was used to characterize the formation of nanocomposites. The thermal properties were characterized by using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The dynamic mechanical properties of PA6/PP nanocomposites were analyzed by using dynamic mechanical thermal analyzer (DMTA). The strength and stiffness of PA6/PP nanocomposites were improved significantly in the presence of MAH-g-PP. This has been attributed to the synergistic effect of organoclay and MAH-g-PP. The MAH-g-PP compatibilized PA6/PP nanocomposites showed a homogeneous morphology supporting the compatibility improvement between PA6, PP and organoclay. TEM and XRD results revealed the formation of nanocomposites as the organoclay was intercalated and exfoliated. A possible chemical interaction between PA6, PP, organophilic modified montmorillonite and MAH-g-PP was proposed based on the experimental work.     

MOLECULAR STRUCTURE AND REACTIVITY OF PETROLEUM RESIDUA

The chloromethylation of petroleum residua — especially the asphaltenea — is described from the chemical and kinetic aspects. Properties of the products are discussed in detail.     

OXIDATIVE REACTIVITY OF PETROLEUM RESIDUES

In this article two oxidation reactions of the oxidation of petroleum residues are considered: catalytic oxidation of tar to bitumens and oxidation of asphaltene concentrates under radiation.