the growth rate and uniformity of carbon nano tubes (cnts) based on chemical vapor deposition (cvd) technique is investigated by using a numerical model. in this reactor, inlet gas mixture, including xylene as carbon source and mixture of argon and hydrogen as  carrier gas enters into a horizontal cvd reactor at atmospheric pressure. based on the gas phase and surface reactions, released carbon...

Due to the recent increase of natural gas production in the U.S., utilizing natural gas for higher-value chemicals has become imperative. Direct methane aromatization (DMA) is a promising process used to convert methane to benzene, but it is limited by low conversion of methane and rapid catalyst deactivation by coking. Past work has shown that membrane separation of the hydrogen produced in th...

light-weight and high strength alloys such as al-mg alloys are used in order to reduce the weight of industrial components. however these materials should be formed at elevated temperatures due to their poor formability at room temperature. hot metal gas forming is one of the high-tech forming processes that is used to solve this problem. recent investigation on tube hydroforming showed positiv...

An accurate description of the fluid flow and heat transfer within a Pressurized Water Reactor (PWR), for the safety analysis and reactor performance is always desirable. In this paper a mathematical model of the fundamental physical phenomena which are associated to a typical PWR is presented. The mathematical model governs the fluid dynamics in the reactor. Using commercial software CFX, a co...

A continuous-flow clinical analyzer for the routine estimation of urea is described that makes use of an immobilized-enzyme nylon-tube reactor as part of a flow-through system (a Technicon AutoAnalyzer I). Results of blood-urea analyses by use of the immobilized urease are compared with determinations made with the diacetyl monoxime method and the urease solution method. Clinical trials carried...

Two types of airlift fermenters, conventional (UT-ALF) and modified (CDT-ALF) were investigated to evaluate their performance with respect to baker’s yeast growth. The riser tube of conventional external loop airlift fermenter is replaced by a converging-diverging tube. The new reactor is called modified airlift reactor. The results were compared for the two types of airlift fermenter (UT-ALF a...

Photoactivated advanced oxidation processes have excellent performance in removing recalcitrant pollutants from water. However, the high operating cost associated with energy consumption of UV lamps is a big drawback. In this work, design and optimization reflector tube-in-tube membrane photoreactor were carried out using ray tracing methodology to maximize light deployed reactor. Simulations d...

The growth rate and uniformity of Carbon Nano Tubes (CNTs) based on Chemical Vapor Deposition (CVD) technique is investigated by using a numerical model. In this reactor, inlet gas mixture, including xylene as carbon source and mixture of argon and hydrogen as  carrier gas enters into a horizontal CVD reactor at atmospheric pressure. Based on the gas phase and surface reactions, released carbon...

Rapid continuous thermal control of chemical reactions such as those for chemical vapor deposition (CVD) growth of nanotubes and nanowires cannot be studied using traditional reactors such as tube furnaces, which have large thermal masses. We present the design, modeling, and verification of a simple, low-cost reactor based on resistive heating of a suspended silicon platform. This system achie...