Iran University of Science and Technology

About: Iran University of Science and Technology is a education organization based out in Tehran, Iran. It is known for research contribution in the topics: Nonlinear system & Finite element method. The organization has 12917 authors who have published 24965 publications receiving 372013 citations. The organization is also known as: Governmental Technical Institute & Advanced Art College.

Existence of solutions for a class of nonlinear Volterra singular integral equations

Abstract: In this paper we prove some results concerning the existence of solutions for a large class of nonlinear Volterra singular integral equations in the space C[0,1] consisting of real functions defined and continuous on the interval [0,1]. The main tool used in the proof is the concept of a measure of noncompactness. We also present some examples of nonlinear singular integral equations of Volterra type to show the efficiency of our results. Moreover, we compare our theory with the approach depending on the use of the theory of Volterra-Stieltjes integral equations. We also show that the results of the paper are applicable in the study of the so-called fractional integral equations which are recently intensively investigated and find numerous applications in describing some real world problems.

Estimating Young's modulus of zona pellucida by micropipette aspiration in combination with theoretical models of ovum

Abstract: The zona pellucida (ZP) is the spherical layer that surrounds the mammalian oocyte. The physical hardness of this layer plays a crucial role in fertilization and is largely unknown because of the lack of appropriate measuring and modelling methods. The aim of this study is to measure the biomechanical properties of the ZP of human/mouse ovum and to test the hypothesis that Young's modulus of the ZP varies with fertilization. Young's moduli of ZP are determined before and after fertilization by using the micropipette aspiration technique, coupled with theoretical models of the oocyte as an elastic incompressible half-space (half-space model), an elastic compressible bilayer (layered model) or an elastic compressible shell (shell model). Comparison of the models shows that incorporation of the layered geometry of the ovum and the compressibility of the ZP in the layered and shell models may provide a means of more accurately characterizing ZP elasticity. Evaluation of results shows that although the results of the models are different, all confirm that the hardening of ZP will increase following fertilization. As can be seen, different choices of models and experimental parameters can affect the interpretation of experimental data and lead to differing mechanical properties.

Nano-porous membrane process for oily wastewater treatment: Optimization using response surface methodology

Abstract: A sheet nano-porous membrane (PAN), nominal pore size 10 nm is experimentally employed in order to treat the oily wastewater in a desalter plant. Response surface methodology (RSM) based on Box–Behnken method is used to design the experiment and analyze five operating parameters including; trans-membrane pressure (TMP), salt concentration, cross flow velocity (CFV), pH and feed temperature. The maximum permeation flux of 180.1 L/m 2 h is identified by RSM at feed temperature of 45 °C, TMP of 4 bar, CFV of 1.3 m/s, pH of 10 and salt concentration of 11.2 g/L. The results show that nano-porous membrane is efficient for treatment of petroleum refinery waste water, so that total suspended solids, total dissolved solids, oil and grease content and chemical and biochemical oxygen demand are increased to 100%, 44.4%, 99.9%, 80.3% and 76.9%, respectively. The treated water by the proposed method meets the process and industrial water quality requirements for the discharge to the environment or reuse as agricultural water.