University of Tabriz

About: University of Tabriz is a education organization based out in Tabriz, Iran. It is known for research contribution in the topics: Population & Nanocomposite. The organization has 12141 authors who have published 20976 publications receiving 313982 citations.

Investigation of hydrochemical characteristics of groundwater in the Harzandat aquifer, Northwest of Iran.

Abstract: The Harzandat plain is part of the East Azerbaijan province, which lies between Marand and Jolfa cities, northwestern of Iran, and its groundwater resources are developed for water supply and irrigation purposes. The main lithologic units consist chiefly of limestone, dolomite, shale, conglomerate, marl, and igneous rocks. In order to evaluate the quality of groundwater in study area, 36 samples were collected and analyzed for various ions. Chemical indexes like sodium adsorption ratio, percentage of sodium, residual sodium carbonate, and permeability index were calculated. Based on the analytical results, groundwater in the area is generally very hard, brackish, high to very high saline and alkaline in nature. The abundance of the major ions is as follows: Cl(-) >HCO3(-)>SO4(2-) and Na(+) >Ca(2+) >Mg(2+) >K(+). The dominant hydrochemical facieses of groundwater is Na(-)Cl type, and alkalis (Na(+), K(+)) and strong acids (Cl(-), SO4(2-) are slightly dominating over alkali earths (Ca(2+), Mg(2+)) and weak acids (HCO3(-), CO3(2-). The chemical quality of groundwater is related to the dissolution of minerals, ion exchange, and the residence time of the groundwater in contact with rock materials. The results of calculation saturation index by computer program PHREEQC shows that nearly all of the water samples were supersaturated with respect to carbonate minerals (calcite, dolomite and aragonite) and undersaturated with respect to sulfate minerals (gypsum and anhydrite). Assessment of water samples from various methods indicated that groundwater in study area is chemically unsuitable for drinking and agricultural uses.

Adaptive group search optimization algorithm for multi-objective optimal power flow problem

Abstract: A new method for solving the multi-objective optimal power flow problem is proposed.Total operation cost, total emitted emission, and proposed N-1 contingency index are considered as objectives.A new security index is proposed.The fuzzy decision-making approach is utilized to handle the multi-objective OPF problem.AGSO is proposed to precise the convergence characteristic of conventional GSO algorithm. This paper presents an adaptive group search optimization (AGSO) algorithm for solving optimal power flow (OPF) problem. In this study, different aspects of the OPF problem are considered to form the accurate multi-objective model. The system total operation cost, the total emission, and N-1 security index are first, second, and third ordered objectives, respectively. Additionally, to consider accurate model of the problem, transmission losses and different equality and inequality constrains, such as feasible operating ranges of generators (FOR) and power flow equations are taken into account. Moreover, this study presents adaptive form of conventional GSO to precise the convergence characteristic of GSO. The effectiveness and accuracy of the proposed method for solving the nonlinear and nonconvex problems is validated by carrying out simulation studies on sample benchmark test cases and 30-bus and 57-bus IEEE standard test systems. Based on the comprehensive simulation studies, the accuracy of the proposed method is validated.