Abstract

In this paper presents two dimensional turbulent flow of different nanofluids and ribs configuration in a circular tube have been numerically investigation using FLUENT 6.3.26. Two samples of CuO and, ZnO nanoparticles with 2% v/v concentration and 40 nm as nanoparticle diameter combined with trapezoidalribs with aspect ratio of p/d=5.72 in a constant tube surface heat flux were conducted for simulation. The results showed that heat flow as Nusselt number for all cases raises with Reynolds number and volume fraction of nanofluid, likewise the results also reveal that ZnO with volume fractions of 2% in trapezoidal ribs offered highest Nusselt number at Reynolds number of Re= 30000.

Key

The present work aimed to study the efficiency of thermal osmosis process for recovery of water from organic wastewater solution and study the factors affecting the performance of the osmosis cell. The driving force in the thermo osmosis cell is provided by a difference in temperature across the membrane sides between the draw and feed solution. In this research used a cellulose triacetate (CTA), as flat sheet membranes for treatment of organic wastewater under orientation membrane of active layer facing feed solution (FS) and draw solution (DS) is placed against the support layer.  The organic materials were phenol, toluene, xylene and BTX (benzene, toluene, and xylene) used as feed solution. The osmotic agent in draw solution was

Abstract  

All central air conditioning systems contain piping system with various components, sizes, material, and layouts. If such systems in operating mode, the flow in piping system and its component such as valves can produce severe vibration due to some flow phenomenon’s. In this research, experimental measurements and numerical simulation are used to study the flow-induced vibration in valves. Computational fluid dynamics (CFD) concepts are included with one-way and two-way fluid-structure interaction concepts by using finite element software Package (ANSYS 14.57). Detection analysis is performed on flow characteristics under operation conditions and relations with structural vibration. Most of

In this investigation, the mechanical properties and microstructure of Metal Matrix Composites (MMCs) of Al.6061 alloy reinforced by ceramic materials SiC and Al₂O₃ with different additive percentages 2.5, 5, 7.5, and 10 wt.% for the particle size of 53 µ_m are studied. Metal matrix composites were prepared by stir casting using vortex technique and then treated thermally by solution heat treatment at 530 ⁰C for 1 hr. and followed by aging at 175 ⁰C with different periods. Mechanical tests were done for the samples before and after heat treatment, such as impact test, hardness test, and tensile test. Also, the microstructure of the metal matrix composites was examine

Geographical, economic, historical, environmental and security factors play a role in strengthening the drive towards union, as well as addressing the need to express regional and federal identity. This is a clear example of this tendency. One legal or one political system with the parts of this united personality retaining their privacy and identity, and there is a delegation to the central entity of the union with some of the common powers while retaining some powers for these parts or states, which means the availability of autonomy for the constituent states of the union and this is the most important characteristic of the federal states or federations It is the autonomy of each state or country participating in the union. Accordingly,

Background: Environmental chemicals are thought to
adversely affect human reproductive function.
Objective : To estimate the concentration of cadmium(Cd)
, lead ( Pb ) and Zinc ( Zn ) in serum and seminal plasma
among infertile men .
Methods: A sample of 70 infertile men was investigated.
The relationship of trace elements concentration in serum and
seminal plasma was studied in relation to sperm density,
motility and sperm count.
Results: Except for Zinc the concentration of (Pb) and (Cd)
were generally higher in serum than in seminal plasma. The
mean concentration of (Zn) in seminal plasma was more than
25 times higher than in serum There were no statistical
significant differences observed in the