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alkej-194
Prediction of Oxygen Mass Transfer Coefficients in Stirred Bioreactor with Rushton Turbine Impeller for Simulated (Non-Microbial) Medias
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 Abstract

The study of oxygen mass transfer was conducted in a laboratory scale 5 liter stirred bioreactor equipped with one Rushton turbine impeller. The effects of superficial gas velocity, impeller speed, power input and liquid viscosity on the oxygen mass transfer were considered. Air/ water and air/CMC systems were used as a liquid media for this study. The concentration of CMC was ranging from 0.5 to 3 w/v. The experimental results show that volumetric oxygen mass transfer coefficient increases with the increase in the superficial gas velocity and impeller speed and decreases with increasing liquid viscosity. The experimental results of kla were correlated with a mathematical correlation describing the influences of the considered factors (the overall power input and the superficial gas velocity) over the studied rages. The predicted kla values give acceptable results compared with the experimental values. The following correlations were obtained:

Air/water system

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Publication Date
Wed Oct 07 2020
Journal Name
Journal Of Legal Sciences
The Legal Value of Indirect Clauses Restricting the Provisions of Guaranteeing Latent Defect in Sales
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The study addresses a set of indirect clauses that exempt from guaranteeing latent defect in sale contracts, in particular contracts between professional and consumer or normal contractor. The analytical comparative method has been adopted in this study through tackling the viewpoints of scholars and judiciary, and analyzing these in the framework of the Mejeleh, applicable in Palestine, along with the civil codes of Egypt, Jordan and Qatar. The study seeks to derive the legal value of the contractual clauses under consideration, and to indicate to what extent the legislator and judiciary contributed in achieving the economic balance of the contract between the two parties.

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Publication Date
Wed Oct 18 2017
Journal Name
Al-kindy College Medical Journal
Non Motor Symptoms In Patients With parkinson's Disease In Baghdad Hospitals
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Background:Parkinson’disease(PD) is a neurodegenerative disorder of the central nervous system characterized by resting tremor, bradykinesia, cogwheel rigidity, and impairment of postural reflexes; the frequency of PD increases with aging.Clinically Parkinson's disease characterized by two groups of symptoms: motor and non-motor symptoms.Non-motor symptoms can be categorized as autonomic, cognitive/psychiatric (may include depression, dementia, anxiety, hallucinations), sensory and rapid eye movements (REM) sleep behavior disorder (RBD).

Objectives:The objectives of this study are to find out the frequency of the non-motor symptoms of idiopathic Parkinson disease in a group of patients in Baghd

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Publication Date
Thu Dec 28 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Spectrophotometric Determination of Sulfamethoxazole Based on Charge-Transfer Complexation with Sodium Nitroprusside
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   A simple, accurate and precise spectrophotometric method has been developed for the analysis of sulfamethoxazole (SMZ) in pure form and pharmaceutical preparation. The method involves a direct charge transfer complexation of sulfamethoxazole (SMZ) with sodium nitroprusside (SNP) in alkaline medium and the presence of hydroxyl amine hydrochloride. Variables affecting the formation of the formed orange colored complex were optimized following two approaches univariate and central composite experimental design (CCD) multivariate. Under optimum recommended conditions, the formed complex exhibits λmax at 512 nm and the method conforms Beer's law for SMZ concentration in the range of 5.0-150.0 (µg.mL-1) with molar absorptivi

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Publication Date
Tue Nov 30 2021
Journal Name
Iraqi Journal Of Science
Broken Rotor Bar Diagnosis via Monitoring Current Spectrum Analysis in Micro Wind Turbine Induction Motor
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Micro wind turbines are generally used in remote locations, and it is difficult and expensive to repair faults which forced the need for condition monitoring and fault diagnosis which has not been used extensively for small turbines. The possibility of utilizing Fast Fourier Transform (FFT) for diagnosis the faults of broken rotor bar in squirrel cage induction motor of a micro wind turbine was investigated. Monitoring and analysis the current spectrum can be effective for diagnosis the early stage of faults and avoid complete catastrophic failure in the motor by powerful virtual instruments and LabVIEW software as an integral part of this instrumentation. Combination advanced signal processing technique with computerized signal processi

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Publication Date
Wed Mar 29 2017
Journal Name
Iraqi Journal Of Pharmaceutical Sciences ( P-issn 1683 - 3597 E-issn 2521 - 3512)
Microbial Contamination of Eye Drops in out Patient in Iraq
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Acontaminated ophthalmic solutions represent a potential cause of avoidable ocular infection. This study aimed to determine the magnitude and pattern of microbial contamination of eye drops in out patient at the department of ophthalmology, at Baghdad national hospital, Iraq. Fifty four vials from the out patient clinic were obtained for microbial examination after an average use of 2 weeks. The dropper tip and the residual eye drop were examined for contamination. The specimens were cultured, the number of colonies counted, the organisms identified. Eight (15%)  out of 54 analyzed vials were contaminated , most bacteria identi

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Publication Date
Fri Aug 31 2012
Journal Name
Al-khwarizmi Engineering Journal
Natural Convection Heat Transfer in an Inclined Open-Ended Square Cavity with Partially Active Side Wall
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This paper reports a numerical study of flow behaviors and natural convection heat transfer characteristics in an inclined open-ended square cavity filled with air. The cavity is formed by adiabatic top and bottom walls and partially heated vertical wall facing the opening. Governing equations in vorticity-stream function form are discretized via finite-difference method and are solved numerically by iterative successive under relaxation (SUR) technique. A computer program to solve mathematical model has been developed and written as a code for MATLAB software. Results in the form of streamlines, isotherms, and average Nusselt number, are obtained for a wide range of Rayleigh numbers 103-106 with Prandtl number 0.71

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Publication Date
Wed Mar 30 2022
Journal Name
Iraqi Journal Of Science
Retrieval of Timewise Coefficients in the Heat Equation from Nonlocal Overdetermination Conditions
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     This paper investigates the simultaneous recovery for two time-dependent coefficients for heat equation under Neumann boundary condition. This problem is considered under extra conditions of nonlocal type. The main issue with this problem is the solution unstable to small contamination of noise in the input data. The Crank-Nicolson finite difference method is utilized to solve the direct problem whilst the inverse problem is viewed as nonlinear optimization problem. The later problem is solved numerically using optimization toolbox from MATLAB. We found that the numerical results are accurate and stable.

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Publication Date
Fri Dec 31 2021
Journal Name
Iraqi Journal Of Laser
Parametric Optimization for Fatigue Life of 6061-T6 Aluminum Thin Sheets Processed with High-Speed Laser Shock Peening
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Abstract: Aluminum alloys grade 6061-T6 are characterized by their excellent properties and processing characteristics which make them ideal for varieties of industrial applications under cyclic loading, aluminum alloys show less fatigue life than steel alloys of similar strength. In the current study, a nanosecond fiber laser of maximum pulse energy up to 9.9 mJ was used to apply laser shock peening process (LSP) on aluminum thin sheets to introduce residual stresses in order to enhance fatigue life under cyclic loading Box-Behnken design (BBD) based on the design of experiments (DOE) was employed in this study for experimental design data analysis, model building and optimization The effect of working parameters spot size (ω), scannin

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Publication Date
Sun Nov 01 2015
Journal Name
Journal Of Engineering
Heat Transfer Characteristics of a Fluid Flow in Multi Tube Heat Exchanger Fitted with Perforated Fins
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The heat transfer and flow resistance characteristics for air flow cross over circular finned tube heat exchanger has been studied numerically and experimentally. The purpose of the study was to improve the heat transfer characteristics of an annular finned-tube heat exchanger for better performance. The study has concentrated on the effect of the number of perforations and perforations shapes on the heat transfer and pressure drop across a staggered finned tube heat exchanger. The Numerical part of present study has been performed using ANSYS Fluent 14.5 using SST Turbulent model, while the experimental study consist from a test rig with different models of heat exchangers and all required measurement devices were build

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Publication Date
Wed Dec 13 2017
Journal Name
Al-khwarizmi Engineering Journal
Cultivation of Microalgae Chlorella vulgaris in Airlift photobioreactor for Biomass Production using commercial NPK Nutrients
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Airlift reactors are widely used in the chemical and biochemical applications as effective contactors for mass and heat transfer. The main advantages of airlift contactor compared with simple bubble column are ease of construction, low shear rate, high capacity, good mixing and liquid circulation without mechanical agitators and circulating pumps.

In this work, growth characteristics of Chlorella vulgaris microalgae were studied in an internal loop airlift photobioreactor for biomass production. The bioreactor operated under batch and semi-continuous culture mode using commercially available 20:20:20+TE NPK fertilizer as nutrients. The experiments were conducted to evaluate the growth rate and biomass productivity of

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