Theoretical and experimental investigations of the transient heat transfer parameters of constant heat flux source subjected to water flowing in the downward direction in closed channel are conducted. The power increase transient is ensured by step change increase in the heat source power. The theoretical investigation involved a mathematical modeling for axially symmetric, simultaneously developing laminar water flow in a vertical annulus. The mathematical model is based on one dimensional downward flow. The boundary conditions of the studied case are based on adiabatic outer wall, while the inner wall is subjected to a constant heat flux. The heat & mass balance equation derived for specified element of bulk water within the annulu

Abstract                                                                  

The aim of the research is to demonstrate the role of uncertainty in adopting the general requirements for the strategic environmental assessment of service departments in Babil Governorate and the Environment Department. By focusing on a range of environmental problems, despite the efforts exerted to deal with the environme

Free water surface constructed wetlands (FSCWs) can be used to complement conventional waste water treatment but removal efficiencies are often limited by a high ratio of water volume to biofilm surface area (i.e. high water depth). Floating treatment wetlands (FTWs) consist of floating matrices which can enhance the surface area available for the development of fixed microbial biofilms and provide a platform for plant growth (which can remove pollutants by uptake).  In this study the potential of FTWs for ammoniacal nitrogen (AN) removal was evaluated using experimental mesocosms operated under steady-state flow conditions with ten different treatments (two water depths, two levels of FTW mat coverage, two different plant densities and

This paper is employed to discuss the effects of the magnetic field and heat transfer on the peristaltic flow of Rabinowitsch fluid through a porous medium in the cilia channel. The governing equations (mass, motion, and energy) are formulated and then the assumptions of long wavelength and low Reynold number are used for simplification. The velocity field, pressure gradient, temperature, and streamlines are obtained when the perturbation technique is applied to solve the nonlinear partial differential equations. The study shows that the velocity is decreased with increasing Hartmann number while it is decreased with increasing the porosity.

Background:

This article introduces a numerical study on heat exchange and corrosion coefficients of Zinc–water nanofluid stream in a circular tube fitted with swirl generator utilizing CFD emulation. Different  forms of swirl generator which have the following properties of plain twisted tape (PTT) and baffle wings twisted tape (BTT) embeds with various ratio of twisting (y = 2.93, 3.91 and 4.89), baffle inclination angles (β = 0°, - 30° and 30) joined with 1%, 1.5% and 2% volume fraction of ZnO nanofluid were utilized for simulation. The results demonstrated that the heat and friction coefficients conducted by these two forms of vortex generator raised with Reynolds number, twist ratio and baffle inclination angles decreases. Likewise, t

Aluminum plasma was generated by the irradiation of the target
with Nd: YAG laser operated at a wavelength of 1064 nm. The
effect of laser power density and the working pressure on spectral
lines generating by laser ablation, were detected by using optical
spectroscopy. The electron density was measured using the Stark
broadening of aluminum lines and the electron temperature by
Boltzmann plot method it is one of the methods that are used. The
electron temperature Te, electron density ne, plasma frequency
and Debye length increased with increasing the laser peak
power. The electron temperature decrease with increasing gas
pressure.

Determination of isotopic composition of strontium and Rubidium in some geological samples was performed by using thermal ionization mass spectrometry. The optimum evaporation and ionization currents were determined for each of strontium and Rubidium, employing double rhenium filament by using faraday cup as detector. The results were compared  with  reference  mater ials (NBS Standards) of Sr and Rb. The

radioactive decay of 87Rb to 87Sr was also determined.