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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
Wed Jan 06 2021
Journal Name
International Journal Of Pharmaceutical Research
New Polymeric Coii, Niii And Cdii Complexes With Tetrazole Schiff-Base Ligands; Synthesis, Spectral Characterisation And Biological Activity
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New Schiff-base ligands bearing tetrazole moiety and their polymeric metal complexes with Co(II), Ni(II) and Cd(II) ions are reported. Ligands were prepared in a multiple-step reaction. The reaction of sodium 2,6- diformylphenolate and cyclohexane-1,3-dione with 5-amino-2-fluorobenzonitrile resulted in the isolation of two precursors sodium 2,6-bis((E)-(3-cyano-4-fluorophenylimino)methyl)-4-methylphenolate 1 and 5,5'- (1E,1'E)-cyclohexane-1,3-diylidenebis- (azan-1-yl-1-ylidene)bis(2-fluorobenzonitrile) 2, respectively. The reaction of precursors with azide gave the required ligands; sodium 2,6-bis((E)-(4-fluoro-3-(1H-tetrazol-5- yl)phenylimino)methyl)-4-methylphenolate (NaL) and (N,N'E,N,N'E)-N,N'-(cyclohexane-1,3-diylidene)bis(4- fluoro-3-

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Publication Date
Wed May 10 2023
Journal Name
Journal Of Engineering
Damage Detection and Assessment of Stiffness and Mass Matrices in Curved Simply Supported Beam Using Genetic Algorithm
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In this study, a genetic algorithm (GA) is used to detect damage in curved beam model, stiffness as well as mass matrices of the curved beam elements is formulated using Hamilton's principle. Each node of the curved beam element possesses seven degrees of freedom including the warping degree of freedom. The curved beam element had been derived based on the Kang and Yoo’s thin-walled curved beam theory. The identification of damage is formulated as an optimization problem, binary and continuous genetic algorithms
(BGA, CGA) are used to detect and locate the damage using two objective functions (change in natural frequencies, Modal Assurance Criterion MAC). The results show the objective function based on change in natural frequency i

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Publication Date
Thu Jan 02 2020
Journal Name
Journal Of The College Of Languages (jcl)
The use of Arabic-Islamic Theme in The Stories of Western writers: El empleo del material árabe-islámico en las historias de los escritores occidentales
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This article presents and  explores the theoretical aspect in the use of Arab Islamic theme by the western writers to obtain and achieve individual motives. In this study the model for the theory of Arab presence in Andalusia  , through the book entitled “ Alhamra” by the English writer Washington Erving ,was  analyzed.

The most important results in this research: the success of  the author in the employment of the Islamic history in the formation of the first American legend, Columbus legend, through the selection of the right thoughts to establish his American National theory.  The author compared between the Andalusia experience and the Arab occupation to Spain and the American conquest of the new

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Publication Date
Sun Feb 28 2021
Journal Name
Jurnal Teknologi
HEAT TRANSFER ENHANCEMENT USING PASSIVE TECHNIQUE: REVIEW
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Preserving and saving energy have never been more important, thus the requirement for more effective and efficient heat exchangers has never been more important. However, in order to pave the way for the proposal of a truly efficient technique, there is a need to understand the shortcomings and strengths of various aspects of heat transfer techniques. This review aims to systematically identify these characteristics two of the most popular passive heat transfer techniques: nanofluids and helically coiled tubes. The review indicated that nanoparticles improve thermal conductivity of base fluid and that the nanoparticle size, as well as the concentrations of the nanoparticles plays a major role in the effectiveness of the nanofluids.

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Publication Date
Sun Mar 02 2008
Journal Name
Baghdad Science Journal
Study the Band Energy Structure and Absorption Coefficient for PbSe Thin Films
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The PbSe alloy was prepared in evacuated quarts tubs by the method of melt quenching from element, the PbSe thin films prepared by thermal evaporation method and deposited at different substrate temperature (Ts) =R.T ,373 and 473K . The thin films that deposited at room temperature (R.T=303)K was annealed at temperature, Ta= R.T, 373 and 473K . By depended on D.C conductivity measurements calculated the density of state (DOS), The density of extended state N(Eext) increases with increasing the Ts and Ta, while the density of localized state N(Eloc) is decreased . We investigated the absorption coefficient (?) that measurement from reflection and transmission spectrum result, and the effect of Ts and Ta on it , also we calculated the tai

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Publication Date
Thu Jul 02 2020
Journal Name
International Journal Of Pharmaceutical Research
The Correlation of TGF-ß Level and GARP Gene Expression in Iraqi Patients with Rheumatoid Arthritis Treated By Biological and Chemo-Therapy
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Publication Date
Sat Aug 01 2020
Journal Name
Key Engineering Materials
Effect of Coefficient of Variation on the Reliability of Collapse Potential's Equation Predicted by ANNs
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In this paper, the Reliability Analysis with utilizing a Monte Carlo simulation (MCS) process was conducted on the equation of the collapse potential predicted by ANN to study its reliability when utilized in a situation of soil that has uncertainty in its properties. The prediction equation utilized in this study was developed previously by the authors. The probabilities of failure were then plotted against a range of uncertainties expressed in terms of coefficient of variation. As a result of reliability analysis, it was found that the collapse potential equation showed a high degree of reliability in case of uncertainty in gypseous sandy soil properties within the specified coefficient of variation (COV) for each property. When t

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Publication Date
Wed Oct 11 2023
Journal Name
Journal Of Educational And Psychological Researches
The Effectiveness of Cognitive-Behavioral Counseling in Reducing Symptoms of Social Anxiety and Improving Social Skills among Intermediate School Students in Dhi Qar Governorate
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The study aims to investigate the effectiveness of cognitive-behavioral counseling in reducing symptoms of social anxiety and improving social skills among a sample of intermediate school students in the city of Souq Al-Shuyukh at Dhi Qar Governorate. The sample consisted of (40) female students, their ages ranged (14-15). They were selected based on their high scores on the social anxiety scale. The sample was divided into two groups: an experimental group, and a control group, equal in number (20) students in each group. The researcher used the social anxiety scale and the social skills scale. In addition, he used the cognitive-behavioral counseling program, consisting of (11) counseling sessions, with a rate of (45) minutes per sessio

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Publication Date
Sat Apr 01 2023
Journal Name
Iop Conference Series: Earth And Environmental Science
Path Coefficient Analyses for Growth and Yield Traits of Barley Under Different Seeding Rates
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Abstract<p>The purpose of this experiment was to determine the relationship between the path coefficient and seed rate for four different barley cultivars (Amal, Ibaa 265, Ibaa 99, and Buhooth 244) during the 2019-2020 winter season. The experiment was carried out using a split plot design with three replications according to a randomized complete block design (RCBD). The highest positive thru effect on grain yield was found for flag leaf area and harvest index at aseeding rate of 130 kg.h<sup>-1</sup>; the highest positive direct effect on grain yield was found for flag leaf area and plant height at aseeding rate of 160 kg.h<sup>-1</sup>; and the highest positive direct effe</p> ... Show More
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Publication Date
Wed Apr 01 2015
Journal Name
Mathematical Methods In The Applied Sciences
An inverse problem of finding the time-dependent diffusion coefficient from an integral condition
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