An -dominance-based multiobjective genetic algorithm for economic emission load dispatch optimization problem

In this paper, a novel multiobjective genetic algorithm approach for economic emission load dispatch (EELD) optimization problem is presented. The EELD problem is formulated as a non-linear constrained multiobjective optimization problem with both equality and inequality constraints. A new optimization algorithm which is based on concept of co-evolution and repair algorithm for handling non-linear constraints is presented. The algorithm maintains a finite-sized archive of non-dominated solutions which gets iteratively updated in the presence of new solutions based on the concept of -dominance. The use of -dominance also makes the algorithms practical by allowing a decision maker to control the resolution of the Pareto-set approximation by choosing an appropriate value.The proposed approach is carried out on the standard IEEE 30-bus 6-genrator test system. The results demonstrate the capabilities of the proposed approach to generate true and well-distributed Pareto-optimal non-dominated solutions of the multiobjective EELD problem in one single run. Simulation results with the proposed approach have been compared to those reported in the literature. The comparison demonstrates the superiority of the proposed approach and confirms its potential to solve the multiobjective EELD problem.     

Deformation and Mechanical Characteristics of Compacted Binary Mixtures of Plastic (Microcrystalline Cellulose), Elastic (Sodium Starch Glycolate), and Brittle (Lactose Monohydrate) Pharmaceutical Excipients

This work studies the tensile strength, coherence, elastic, and plastic energy of single and bi-component compacted tablets consisting of (i) microcrystalline cellulose (MCC) PH 102 as a plastic material, (ii) (SSG) as an elastic material, and (iii) alpha lactose monohydrate as a brittle material by direct compression. Compacted tablets were studied with various mass ratios formed at an ultimate compaction stress of 150 MPa. The loading and unloading stages of the compaction process for the single and binary tablets were evaluated based on the energies derived from the force-displacement data obtained. The resulting tablet quality was measured in terms of the tensile strength. Material that exhibit predominantly plastic deformation (MCC) shows a dominant property over elastically deforming sodium starch glycolate (SSG) and brittle (lactose) materials during the loading and unloading stages of the compaction process. In conclusion, the tensile strength of the formed tablets depends directly on the plastic energy and indirectly on the elastic energy and is negatively affected by the presence of a brittle material.     

A new modified differential evolution algorithm scheme-based linear frequency modulation radar signal de-noising

The main intention of this study was to investigate the development of a new optimization technique based on the differential evolution (DE) algorithm, for the purpose of linear frequency modulation radar signal de-noising. As the standard DE algorithm is a fixed length optimizer, it is not suitable for solving signal de-noising problems that call for variability. A modified crossover scheme called rand-length crossover was designed to fit the proposed variable-length DE, and the new DE algorithm is referred to as the random variable-length crossover differential evolution (rvlx-DE) algorithm. The measurement results demonstrate a highly efficient capability for target detection in terms of frequency response and peak forming that was isolated from noise distortion. The modified method showed significant improvements in performance over traditional de-noising techniques.     

Synthesis and characterization of novel Schiff‐base polyamides from copper/benzil bisthiosemicarbazone complexes

A new copper‐containing Schiff‐base diamine, benzil bis(thiosemicarbazonato)copper(II) (CuLH₄), was synthesized in two steps from benzil bisthiosemicarbazone (LH₆). The ligand LH₆ and the complex CuLH₄ were characterized with Fourier transform infrared spectroscopy, ¹H‐NMR, and elemental analysis. CuLH₄ was used to prepare novel polyamides. The low‐temperature solution polycondensation of the complex CuLH₄ with various aromatic and aliphatic diacid chlorides afforded copper‐containing Schiff‐base polyamides with inherent viscosities of 0.25–0.36 dL/g in N,N‐dimethylformamide (DMF) and 0.75 dL/g in H₂SO₄ at 25°C. The polyamides were generally soluble in a wide range of solvents, such as DMF, N,N‐dimethylacetamide, tetrahydrofuran, dimethyl sulfoxide, ethyl acetate, tetrachloroethane, hexamethylene phosphoramide, N‐methylpyrrolidone, and pyridine. Thermal analysis showed that these polyamides were practically amorphous, decomposed above 270°C, and exhibited 50% weight loss at and above 400°C. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Synthesis of high performance polyamides utilizing copper‐catalyzed amidation of a dibromoarene with different diamides

A series of diphenylquinoxaline‐containing polyamides were prepared from the condensation polymerization of 2,3‐bis (4‐bromophenyl) quinoxaline (DBQ) with various primary and secondary diamides via copper‐catalyzed amidation reaction. The polyamides were characterized with FTIR, NMR, GPC, differential scanning calorimeter, and thermo gravimetric analysis, and their solubility and viscosity were measured. The polyamides synthesized here are amorphous and showed relatively good solubility in polar aprotic solvents and demonstrate the ability to form brownish hard films by solvent casting; their inherent viscosities ranged from 49 to 55 mL/g. The average molecular weights of polyamides were in the range of M_w = 11,950–5592 g/mol (MWD = 1.21–1.87). These polyamides had relatively high thermal stability with T_g values up to 276°C, 10% weight loss temperatures (T_10%) in the range of 364–476°C, and char yields at 600°C in N₂ up to 72%. They also exhibit emission in the solid state and in dilute (0.2 g/dL) DMAc solution at 425–484 nm with photoluminescence quantum (?_f) yields in the range of 14–23%. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Thermal and rheological properties of the supersaturated sucrose solution in the presence of different molecular weight fractions and concentrations of dextran

In our current research work, we investigated the effects of molecular weight (M _w) and the concentration of dextran presence during cane sugar manufacturing on the rheological and glass transition properties of supersaturated sucrose solution. Three dextrans of various M _w, namely 100,000 g/mol (T ₁₀₀), 500,000 g/mol (T ₅₀₀) and 2,000,000 g/mol (T ₂₀₀₀), were admixed in concentrations between 1,000 and 10,000 ppm with 65 and 75% w/w sucrose solution. The results indicated that both the apparent viscosity and dynamic modulus increased with an increase in dextran concentrations and they demonstrated strong dependence on its M _w. Glass transition temperature (T _g) of the samples was measured by differential scanning calorimetry, and their dependence on dextran M _w and concentration was analyzed by the Fox and expanded Gordon–Taylor mathematical models. It was found that the higher the M _w and concentration of the dextran, the greater the increase in T _g. The expanded Gordon–Taylor equation has proved useful in predicting the T _g of the sucrose solution in the presence of polymer.     

Textile applications of photochromic dyes. Part 4: application of commercial photochromic dyes as disperse dyes to polyester by exhaust dyeing

A series of commercial photochromic dyes was applied to polyester fabric as disperse dyes. The photocoloration properties of the dyed fabrics were investigated by applying techniques previously established in our laboratories using an independent source of ultraviolet irradiation and traditional colour measurement instrumentation. The dyed fabrics showed reversible photochromism, developing pronounced colours from weak background colours on irradiation with ultraviolet light and returning to their original state when the ultraviolet light source was removed. However, the extent of photocoloration and the depth of background colour varied significantly with the particular dye used. The dyeing procedure was optimised by maximising the degree of photocoloration, expressed as the colour difference (ΔE₁) between the colour developed after ultraviolet exposure and background colour, while minimising the background colour, expressed as the colour difference (ΔE₂) between unexposed dyed and undyed fabrics. Optimum dyeing concentrations were determined. The colour development and fading properties, fatigue resistance and storage stability of the dyed fabrics were investigated.