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alkej-271
Modeling of Mass Transfer Coefficient in Rotating Biological Contactor with Perforated Discs (RPBC)
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Abstract

 In order to make an improvement associated with rotating biological contactor (RBC), a new design of biofilm reactor called as Rotating perforated disc biological contactor (RPBC) was developed in which the rotating discs are perforated. The transfer of oxygen from air to wastewater was investigated. Mass-transfer coefficient (KLa)  in the liquid phase was determined by measuring  the rate transfer of oxygen.  A   laboratory scale of (RPBC) consisted of a semicircular trough was used with a working capacity of 40 liters capacity of liquid. Synthetic wastewater was used as a liquid phase, while air was used as a gas phase.

The effects of many parameters on the liquid phase mass transfer coefficient (KLa) were investigated. These parameters are; the disc rotational speed (N), the pore diameter (d) and clearance between the discs(C). It was found that the value of KLa was increased as the rotation speed (N) increased, and as  the diameter of the pores in  the disc  (d) increased. While the values of (KLa) was decreased continuously with increasing the clearance(C). Suitable correlation was developed for estimating mass transfer coefficient (KLa) in this type of bioreactor.

 Keywords: Rotating biological contactor, Mass transfer coefficient, Wastewater treatment.

 

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Publication Date
Mon Jun 01 2009
Journal Name
Al-khwarizmi Engineering Journal
Simulation of Free Convection from an Inclined Heated Thin Plate in a Square Enclosure
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Simulation of free convection heat transfer in a square enclosure induced by heated thin plate is represented numerically. All  the enclosure walls have constant temperature lower than the plate’s temperature. The flow is assumed to be two-dimensional. The discretized equations were solved stream function, vorticity, and energy equations by finite difference method using explicit technique and Successive Over- Relaxation method. The study was performed for different values of Rayleigh number ranging from 103 to 105 for different angle position of heated thin plate(0°, 45°, 90°). Air was chosen as a working fluid (Pr = 0.71). Aspect ratio of center of plate to the parallel left wall A2

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Publication Date
Thu Feb 07 2019
Journal Name
Iraqi Journal Of Laser
Study the Effect of PH Variation on the Particle Size of Sio2 Thin Films
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In this paper, SiO2 nanoparticles thin films were synthesised at different PH values of solution by sol gel method at fixed temperature (25oC) and molar ratio (R =H2O/precursor) of (Tetra Ethyl Ortho Silicate) TEOS as precursor at (R=1). The structure and optical properties of the thin films have been investigated. All thin films were tested by using X-RAY diffraction. All X-RAY spectrum can be indexed as monoclinic structure with strong crystalline (110) plane. The morphological properties of the prepared films were studied by SEM. The results indicate that all films are in nano scale and the particle size around (19-62) nm .The size of silica particles increases with increasing PH value of solution where both the rate of hydrolysis and

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Publication Date
Tue Jan 01 2019
Journal Name
Energy Procedia
Humidity effect on diffusion and length coefficient of radon in soil and building materials
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Publication Date
Sat Mar 30 2013
Journal Name
Mathematical Problems In Engineering
CFD analysis of Heat transfer and friction factor characteristics in a circular tube fitted with Quadrant-cut twisted tape inserts
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Publication Date
Tue Sep 01 2020
Journal Name
Journal Of Engineering
Experimental Study on Heat Transfer and Flow Characteristics in Subcooled Flow Boiling in a Microchannel
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The current study presents an experimental investigation of heat transfer and flow characteristic for subcooled flow boiling of deionized water in the microchannel heat sink. The test section consisted of a single microchannel having 300μm wide nominal dimensions and 300μm height (hydraulic diameter of 300μm). The test section formed of oxygen-free copper with 72mm length and 12mm width. Experimental operation conditions spanned the heat flux (78-800) kW/m2, mass flux (1700 and 2100) kg/m2.s at 31˚C subcooled inlet temperature. The boiling heat transfer coefficient is measured and compared with existing correlations. Also, the experimental pressure drop is measured and compared with microscale p

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Publication Date
Sun Jun 05 2011
Journal Name
Baghdad Science Journal
Synthesis, spectroscopic and biological studies of some metal complexes with orthoamino hydrazo benzene
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Ortho amino hydrazobenzene (L) has been prepared from the reaction of ortho amino phenyl thiol with phenyl hyrazan in mole ratio(1:1). It has been characterized by elemental analysis (C, H, N), IR, UV–Vis. The complexes of the bivalent ions (Co, Ni, Cu, Zn, Pd, Cd, Hg and Pb) and the trivalent (Cr) have been prepared and characterized too. The structural have been established by elemental analysis(C,H,N), IR , UV – Vis spectra , conductivity measurements , atomic absorption and magnetic susceptibility . The complexes showed characteristic behaviour of octahedral geometry around the metal ion and the( N,N) ligand coordinated in bidentate modeexcept with pd showed square planer. ? ,kf , ?max for the complexes were estimated too .

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Publication Date
Wed Oct 17 2018
Journal Name
Journal Of Economics And Administrative Sciences
the role of marketing intelligence in promoting new product policies.a sample survey of workers in a number of mineral water plants in dohuk governorate
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Marketing Intelligence is one of the important methods of collecting information about competitors ' products and changes in customers ' tastes and needs that contribute to determining the policies to be followed in product development.

The problem of research, which seeks to be answered by the extent to which the companies in question have the appropriate and effective mechanisms to develop their products, and the nature of the relationship between the components of marketing intelligence and new product development policies. The importance of research is determined by the importance of obtaining important and necessary information to make the appropriate decision on the development of the new product an

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Publication Date
Mon Aug 01 2022
Journal Name
Baghdad Science Journal
Detection of Methamphetamine using Nanobentonite as a Novel Solid Phase Extraction Column Matrix Assisted with Gas Chromatography- Mass Spectroscopy
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          This study was done to evaluate a new technique to determine the presence of methamphetamine in the hair using nano bentonite-based adsorbent as the filler of extraction column. The state of the art of this study was based on the presence of silica in the nano bentonite that was assumed can interact with methamphetamine. The hair used was treated using methanol to extract the presence of methamphetamine, then it was continued by sonicating the hair sample. Qualitative analysis using Marquish reagent was performed to confirm the presence of methamphetamine in the isolate.The hair sample that has been taken in a different period confirmed that this current developing method can be used to analyzed methamphetamine. This m

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Publication Date
Wed Feb 20 2019
Journal Name
Political Sciences Journal
A political perusal of Initiations in Declaring Middle East a District vacant of mass Destruction weapons
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A political perusal of Initiations in Declaring Middle East a District vacant of mass Destruction weapons

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Publication Date
Fri Feb 14 2020
Journal Name
Journal Of Mechanical Engineering Research And Developments
Noise effects in skill discretion and modeling
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Diesel generators is widely used in Iraq for the purpose of maintaining electric power demand. Large number of operators engaged in this work encounters high level of noise generated by back pack type diesel generators used for this purpose. High level of noise exposure gives different kinds of ill effect on human operators. Exact nature of deteriorated work performance is not known., in present research , quastionaire was adsministered 86 repondents in Baghdad city were exposured to wide range of noise level (80-110) dB(A) with different ages and they have different skill discretion levels. Noise levels A-weigthed decibles dB(A) were measured over 8 weeks two times aday during the 2019 summer using a sound level meter.For predicting the wo

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