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.

Preparation of a Novel Polyvinylidene Fluoride (PVDF) Ultrafiltration Membrane Modified with Reduced Graphene Oxide/Titanium Dioxide (TiO2) Nanocomposite with Enhanced Hydrophilicity and Antifouling Properties

Abstract: A novel polyvinylidene fluoride (PVDF) mixed matrix ultrafiltration membrane containing reduced graphene oxide/titanium dioxide (rGO/TiO2) nanocomposite was prepared by phase inversion method. The synthesized rGO/TiO2 was characterized by X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy (SEM) techniques. The prepared rGO/TiO2 blended PVDF membranes were characterized by atomic force microscopy, SEM, water contact angle, porosity, permeation measurements, and rejection tests. Due to the high hydrophilicity of the rGO/TiO2 nanocomposite, the rGO/TiO2/PVDF membranes were more hydrophilic and had higher pure water flux and flux recovery ratio than the bare PVDF. The blended membranes showed remarkably good properties and performance when the rGO/TiO2 content of 0.05 wt % was added to the casting solution. The pure water flux of the 0.05 wt % rGO/TiO2 blended membrane was increased by 54.9% compared with the bare PVDF membrane. The antifouling study of the membranes ...

A Nonisolated Multiinput Multioutput DC–DC Boost Converter for Electric Vehicle Applications

Abstract: A new nonisolated multiinput multioutput dc-dc boost converter is proposed in this paper. This converter is applicable in hybridizing alternative energy sources in electric vehicles. In fact, by hybridization of energy sources, advantages of different sources are achievable. In this converter, the loads power can be flexibly distributed between input sources. Also, charging or discharging of energy storages by other input sources can be controlled properly. The proposed converter has several outputs with different voltage levels which makes it suitable for interfacing to multilevel inverters. Using of a multilevel inverter leads to reduction of voltage harmonics which, consequently, reduces torque ripple of electric motor in electric vehicles. Also, electric vehicles which using dc motor have at least two different dc voltage levels, one for ventilation system and cabin lightening and other for supplying electric motor. The proposed converter has just one inductor. Depending on charging and discharging states of the energy storage system (ESS), two different power operation modes are defined for the converter. In order to design the converter control system, small-signal model for each operation mode is extracted. The validity of the proposed converter and its control performance are verified by simulation and experimental results for different operation conditions.

Analysis of heat conduction in a disk brake system

Abstract: In this paper, the governing heat equations for the disk and the pad are extracted in the form of transient heat equations with heat generation that is dependant to time and space. In the derivation of the heat equations, parameters such as the duration of braking, vehicle velocity, geometries and the dimensions of the brake components, materials of the disk brake rotor and the pad and contact pressure distribution have been taken into account. The problem is solved analytically using Green’s function approach. It is concluded that the heat generated due to friction between the disk and the pad should be ideally dissipated to the environment to avoid decreasing the friction coefficient between the disk and the pad and to avoid the temperature rise of various brake components and brake fluid vaporization due to excessive heating.