Showing papers by "Islamic Azad University published in 2005"

A Genetic–Based Tabu Search Algorithm for Optimal DG Allocation in Distribution Networks

Abstract: This article presents a new optimization algorithm based on integrating the use of genetic algorithms and tabu search methods to optimal allocation of dispersed generation resources in distribution networks. The proposed algorithm finds how much distribution losses can be reduced if dispersed generations are optimally allocated at the demand side of power system. A significant improvement of the proposed algorithm results, over that obtained by genetic algorithm, has been achieved. Numerical examples also showed the superiority of the proposed algorithm compared with the simple genetic algorithm.

A combination of genetic algorithm and simulated annealing for optimal DG allocation in distribution networks

Abstract: This paper presents a new algorithm based on integrating the use of genetic algorithms and simulated annealing methods to optimal allocation of distributed generation resources in distribution networks. Through this algorithm a significant improvement in the optimization goal is achieved. With a numerical example the superiority of the proposed algorithm is demonstrated in comparison with the simple genetic algorithm

Tuning of reachable set in one dimensional fuzzy differential inclusions

Abstract: This paper presents a new numerical method for solving one dimensional fuzzy differential inclusions. An efficient algorithm to solve them in MAPLE has been devised, which is easy to implement.

Optimal distributed generation allocation in distribution network using Hereford Ranch algorithm

Abstract: The necessity for flexible electric systems, energy saving, loss reducing and environmental impact are providing impetus to the development of distributed generation (DG). DG includes the application of small generators, scattered throughout a power system, to provide the electric power needed by electrical customer. Such locally distributed generation, has several merits from the viewpoint of environmental restriction and location limitations, as well as transient and voltage stability in the power system. The exact solution of the DG allocation can be obtained by a complete enumeration of all feasible combinations of sites and sizes of DGs in the network. The number of alternatives could be very large, however load flow should be performed for each feasible combination and selection of the optimized solution among these alternatives is an important task. The problem is to determine site and size of DG that minimizes the distribution power losses under the condition that number of DGs and total capacity of DGs are known. Artificial intelligence techniques have come to be most widely used tool for solving optimal DG allocation. Genetic algorithm (GA) is an efficient tool to solve optimization problems. Generally, GA's ability to find a correct solution in a variety of problems, to preserve diversity for preventing premature convergence and to improve convergence time is affected by parent selection algorithm for generating offspring. In this paper, to overcome the defects of existing simple genetic algorithm (SGA), Hereford Ranch algorithm (HRA), is applied to search optimal site and size of DG in distribution feeders. HRA uses sexual differentiation and selective breeding in choosing parents for genetic string. The proposed method was tested for 34-node IEEE distribution test feeder

Crystal Structures and Solution Studies of Two Novel Zinc(II) Complexes of a Proton Transfer Compound Obtained from 2, 6-Pyridinedicarboxylic Acid and 1, 10-Phenanthroline: Observation of Strong Intermolecular Hydrogen Bonds

Abstract: The proton transfer compound LH2, (phenH+)2(pydc2—), has been prepared from 1, 10-phenanthroline, phen, and 2, 6-pyridinedicarboxylic acid, (dipicolinic acid), pydcH2. Characterization was performed using solution and solid phase CP/MAS 13C NMR and IR spectroscopy. The reactions of this adduct with ZnSO4·7H2O and Zn(NO3)2·4H2O give the complexes, [Zn(pydc)2][Zn(phen)2(H2O)2]·7H2O (1) and [Zn(phen)3]4(H(Hpydc)2)(NO3)7·26H2O (2), respectively. These complexes were characterized by 1H and 13C NMR spectroscopy and single crystal X-ray analysis. The complexes crystallize in the triclinic space group P1 with Z = 2. The unit cell dimensions for complex 1 and 2 are: a = 9.9838(9) A, b = 14.7483(13) A, c = 14.8365(13) A and a = 12.640(4) A, b = 15.855(5) A, c = 21.830(7) A, respectively. In complex 1 (pydc2—) and phen, are tri- and bidentate ligands, respectively, and an anionic [Zn(pydc)2]2— and cationic [Zn(phen)2(H2O)2]2+ complex are formed simultaneously. In complex 2, three phen participate in complexation leaving hydrogen-bis(pyridine-2-carboxylate), (H(Hpydc)2)— as a supramolecular anion. The fragments (H(Hpydc)2)—, 7 NO3—, and 26 H2O in complex 2 are joined together by extensive and strong H-bonding; therefore, the structure is composed of [Zn(phen)3]48+, and an anionic hydrogen bond supramolecular assembly with the formula, {(H(Hpydc)2(NO3)7)8—·26H2O}n. The anionic species (H(Hpydc)2)— has a special position at the inversion center, as well as one of the NO3— anions, which is disordered over the inversion center. Most of the hydrogen bonds in complex 2 represent strong H-bonding. The protonation constants of the building blocks of the pydc-phen adduct, the equilibrium constants for the reaction of (pydc2—) with phenanthroline and the stoichiometry and stability of the ZnII complex with LH2 on aqueous solution were determined by potentiometric pH titration. The solution study results support self-association between (pydc2—) and (phenH+) with a stoichiometry for the Zn(II) complex similar to that observed for the isolated crystalline complex. Kristallstrukturen und Untersuchungen in Losung von zwei neuene Zink(II)-Komplexen einer Protontransfer-Verbindung aus 2, 6-Pyridindicarboxy-Saure und 1, 10-Phenanthrolin — Beobachtung starker intermolekularer Wasserstoffbruckenbindungen Die Protontransfer-Verbindung LH2, (phenH+)2(pydc2—), wurde aus 1, 10-Phenanthrolin, phen, und 2, 6-Pyridindicarboxy-Saure, (Dipicolin-Saure), pydcH2, dargestelltund charakterisiert durch CP/MAS-13C-NMR in Losung und festem Zustand sowieIR-Spektroskopie. Die Reaktion dieses Addukts mit ZnSO4·7H2O bzw. Zn(NO3)2·4H2O fuhrte zu Komplexen mit der Zusammensetzung [Zn(pydc)2][Zn(phen)2(H2O)2]·7H2O (1) und [Zn(phen)3]4(H(Hpydc)2)(NO3)7·26H2O (2), die ebenfalls mit 1H- und 13C-NMR spektroskopisch and durch Rontgenstrukturanalyse charakterisiert wurden. DieKomplexe kristallisieren in der triklinen Raumgruppe P1¯ mit Z = 2. Die Gitterparameter fur 1 und 2 sind: a = 9.9838(9) A, b = 14.7483(13) A, c = 14.8365(13) A bzw. a = 12.640(4) A, b = 15.855(5) A, c = 21.830(7) A. Im Komplex 1 fungieren die Eddukte (pydc2—) und phen als drei- und zweizahnige Liganden und es wird sowohl ein [Zn(pydc)2]2—-Anion- als auch ein [Zn(phen)2(H2O)2]2+-Kation-Komplex gleichzeitig gebildet. Im Fall von Komplexes 2 nehmen drei phen Molekule an der Koordination teil und es wird ein supermolekulares Anion aus Hydrogen-bis(pyridine-2-carboxylate), (H(Hpydc)2)— gebildet. Die Fragmente (H(Hpydc)2)—, 7 NO3— und 26 H2O im Komplex 2 sind durch sehr starke undextensive Wasserstoffbruckenbindungen verbunden. Daraus entsteht eine Struktur aus dem [Zn(phen)3]48+-Ion und einem anionische, durch H-Bruckenbindungen aufgebautem supramolekularem Ensemble mit der Formel, {(H(Hpydc)2(NO3)7)8—· 26H2O}n. Die anionische Spezies (H(Hpydc)2)— wie die NO3—-Anionen, die uber das Inversionzentrum fehlgeordnet sind, haben eine spezielle Position auf dem Inversionzentrum. Die Mehrheit der H-Bruckenbindungen des Komplexs 2 sind starke Bindungen. Die Protonierungskonstante der Aufbaueinheiten des pydc-phen Adduktes, die Gleichgewichtskonstanten fur die Reaktion von (pydc2—) mit Phenanthrolin und die Stochiometrie und Stabilitat des ZnII-Komplexes mit LH2 in wasriger Losung sind mit Hilfe potentiometrischer pH-Titration bestimmt worden. Die Untersuchungen zur Losung deuten auf Slbstassoziation zwischen (pydc2—) und (phenH+) mit einer Stochiometrie des ZnII-Komplexes ahnlich der des isolierten kristallinen Komplexes hin.

Biosorption of Pb, Cd, Cu and Zn from the wastewater by treated Azolla filiculoides with H2O2/MgCl2

Abstract: The adsorption of heavy metals onto treated Azolla filiculoides by H2O2/MgCl2, as a cosmopolitan free-floating waterfern, was investigated from aqueous solutions in the batch biosorption experiments. The maximum uptake capacities of the collected Azolla from rice field at the optimal conditions for Pb, Cd, Cu and Zn ions were approximately 228, 86, 62 and 48 mg/g (dry Azolla), respectively. On the other hand, the maximum uptake capacities of the collected Azolla from the Anzali International Wetland in the north part of Iran at the same conditions for these heavy metals were about 124, 58, 33 and 34 mg/g (dry Azolla), respectively. Such decrease of uptakes is due to the pollution of Anzali International Wetland, which reduces the capacity uptake of metals. The recovery of biosorbed heavy metals from the rice field Azolla was carried out by HCl and NaCl desorbents that the recovery of 64–86% and 51–72% was occurred, respectively.

An Effective Method for Producing a Nutritive Protein Extract Powder from Shrimp-head Waste

Abstract: Enzymatic hydrolysis has been widely applied for production of protein hydrolysate from shrimp waste and for purification of chitin. In the present study, shrimp (P. semisulcatus) head waste was hy...

Highly Selective and Sensitive Copper(II) Membrane Sensors Based on 6‐Methyl‐4‐(1‐phenylmethylidene)amino‐3‐thioxo‐1,2,4‐triazin‐5‐one as a New Neutral Ionophore

Abstract: A new Cu(II) ion-selective PVC membrane sensor based on 6-methyl-4-(1-phenylmethylidene)amino-3-thioxo-1,2,4-triazin-5-one (MATTO) as an excellent sensing material was developed. The electrode exhibits a Nernstian slope of 29.2±0.4 mV per decade over a very wide concentration range between 1.0×10−1 and 1.0×10−6 M, with a detection limit of 4.8×10−7 M (30.5 ng/mL). The sensor possesses the advantages of short conditioning time, fast response time (<10 s), and especially, very good selectivity towards transition and heavy metal, and some mono, di and trivalent cations. The proposed electrode was successfully applied to the determination of copper in wastewater of copper electroplating samples and as an indicator electrode in potentiometric titration of Cu(II) ions with EDTA.