Preferred Language
Articles
/
alkej-140
Estimation of Volumetric Mass Transfer Coefficient in Bioreactor
...Show More Authors

 

This study is concentrated to investigate the effects of aeration and stirring speed on the volumetric mass transfer coefficient (KLa). A dynamic technique was used in estimating KLa values in order to achieve the aim of this study.

This study was done in 10L bioreactor by using two medias:-

  1. Dionized water
  2. Xanthan solution (1 g /L)

Moreover, the research covered a comparison between the obtained values of KLa.

The Xanthan solution was used because of its higher viscosity in comparison with water. It behaves similarly to the cultivation medium when organisms are cultivated in a bioreactor. Growth of organisms in the reactor leads to a change in the viscosity of the medium which affects the mass transfer.

Two variables, the effect of air flow rate (3-20 L/min) and the effect of stirring speed (250-700rpm) on KLa value were studied. Other parameters such as temperature, liquid volume, and stirrer shape and stirrer position were held constant; the results demonstrated an increase in KLa – value and mass transfer with increasing stirrer speed. Thus at higher speed, better dispersion of the bubbles was obtained. Therefore, that increased the surface / volume ratio which increased the mass transfer area i.e. KLa value.

View Publication Preview PDF
Quick Preview PDF
Publication Date
Fri Mar 01 2013
Journal Name
Journal Of Economics And Administrative Sciences
Robust Two-Step Estimation and Approximation Local Polynomial Kernel For Time-Varying Coefficient Model With Balance Longitudinal Data
...Show More Authors

      In this research, the nonparametric technique has been presented to estimate the time-varying coefficients functions for the longitudinal balanced data that characterized by observations obtained through (n) from the independent subjects, each one of them is measured repeatedly by group of  specific time points (m). Although the measurements are independent among the different subjects; they are mostly connected within each subject and the applied techniques is the Local Linear kernel LLPK technique. To avoid the problems of dimensionality, and thick computation, the two-steps method has been used to estimate the coefficients functions by using the two former technique. Since, the two-

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sun Sep 01 2019
Journal Name
Journal Of Physics: Conference Series
The combined effectiveness of magnetic force and heat\mass transfer on peristaltic transportation “Hyperbolic Tangent” Nanofluid in a Slopping Non-Regular Non-symmetric Channel.
...Show More Authors
Abstract<p>in the present article, we present the peristaltic motion of “Hyperbolic Tangent nanofluid” by a porous area in a two dimensional non-regular a symmetric channel with an inclination under the impact of inclination angle under the impact of inclined magnetic force, the convection conditions of “heat and mass transfer” will be showed. The matter of the paper will be further simplified with the assumptions of long wave length and less “Reynolds number”. we are solved the coupled non-linear equations by using technical analysis of “Regular perturbation method” of series solutions. We are worked out the basic equations of continuity, motion, temperature, and volume fraction</p> ... Show More
View Publication
Scopus (1)
Scopus Crossref
Publication Date
Sun Jun 30 2019
Journal Name
Journal Of The College Of Education For Women
Antonia's Mannish Behavioral Transition in Willa Cather's Novel My Antonia
...Show More Authors

This paper aims to study Antonia's character and  her mannish behavioral  transition  throughout the novel entitled My Antonia. Willa presents Antonia who shows her resolution and courage in facing and dealing with personal dilemmas and social circumstances. Willa portrays Antonia, who struggles in the new society and culture by working hard in changing the salty land of Nebreska and her destiny . Working in salty land day and night forces Antonia to lose her tender behavior and her  beauty as a woman is changed too. She achieves her goals to live with her family in a new place with a dignity and respect though she looks like a man in her strength and body built . Willa Cather tries to explain that the major&

... Show More
View Publication Preview PDF
Publication Date
Mon Dec 31 2012
Journal Name
Al-khwarizmi Engineering Journal
Experimental Study on the Impact of External Geometrical Shape on Free and Forced Convection Time Dependent Average Heat Transfer Coefficient during Cooling Process
...Show More Authors

In this research, an experimental study was conducted to high light the impact of the exterior shape of a cylindrical body on the forced and free convection heat transfer coefficients when the body is hold in the entrance of an air duct. The impact of changing the body location within the air duct and the air speed are also demonstrated. The cylinders were manufactured with circular, triangular and square sections of copper for its high thermal conductivity with appropriate dimensions, while maintaining the surface area of all shapes to be the same. Each cylinder was heated to a certain temperature and put inside the duct at certain locations. The temperature of the cylinder was then monitored. The heat transfer coefficient were then cal

... Show More
View Publication Preview PDF
Publication Date
Tue Dec 01 2015
Journal Name
Chemical Engineering Science
Airlift bioreactor for biological applications with microbubble mediated transport processes
...Show More Authors

View Publication
Scopus (97)
Crossref (90)
Scopus Clarivate Crossref
Publication Date
Tue Apr 01 2014
Journal Name
Journal Of The Faculty Of Medicine Baghdad
The Use of Volumetric Chest Computed Tomography in Determination of Chronic Obstructive Pulmonary Disease Phenotypes
...Show More Authors

Background: Chronic Obstructive Pulmonary Disease (COPD) represents one of the major causes of chronic morbidity where, airflow limitation is caused by a mixture of small airways disease and parenchyma destruction.
Objective: to correlate the clinical characteristics of patients with COPD with imaging classification into phenotypes.
Patients and Methods: Thirty patients with stable COPD were examined by chest CT. Bronchial wall thickness is evaluated by measuring the wall area percentage by identifying the trunk of the apical bronchus of the right upper lobe, while the extent of emphysema was assessed using the percentage of lung voxels with X-ray attenuation values less than -950 HU {automatically calculated by special software}.<

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sat Dec 30 2023
Journal Name
Iraqi Journal Of Science
Influence of Rotation and Inclined Magnetic Field with Mixed Convective Heat and Mass Transfer in an Inclined Symmetric Channel on Peristaltic Flow with Slip Conditions
...Show More Authors

     In paper, we study the impact of the rotationn inclined magnetic felid and inclined symmetric channel with slip condition on peristaltic transport using incompressible non-Newtonian fluid. Slip conditions for the concentration and heat transfer are considered. We use the conditions on the fluid, namely infinite wavelength and low - Reynolds number to simplify the governed equations that described - motion flow, energy and concentration. These equations ofroblem are solved by the perturbation technique and restricted the number of Bingham to a small value to find the final expression of the stream function. The Bingham number, Brinkman number, Soret number, Dufour number, temperature, Hartman number and other parameters are teste

... Show More
View Publication Preview PDF
Scopus Crossref
Publication Date
Wed Jan 01 2020
Journal Name
Annals Of Tropical Medicine And Public Health
Volumetric assessment of maxillary sinus in cleft lip and palate patients in comparison to normal subjects
...Show More Authors

View Publication
Scopus (4)
Crossref (2)
Scopus Crossref
Publication Date
Tue Jun 01 2021
Journal Name
Civil Engineering Journal
Marshall Performance and Volumetric Properties of Styrene-Butadiene-Styrene Modified Asphalt Mixtures
...Show More Authors

The durability of asphalt pavement is associated with the properties and performance of the binder. This work-study intended to understand the impact of blending Styrene-Butadiene-Styrene (SBS) to conventional asphalt concrete mixtures and calculating the Optimum Asphalt Content (OAC) for conventional mixture also; compare the performance between SBS modified with the conventional mixture. Two different kinds of asphalt penetration grades, A.C. (40-50) and A.C. (60-70), were improved with 2.5 and 3.5% SBS polymer, respectively. Marshall properties were determined in this work. Optimum Asphalt Content (OAC) was 4.93 and 5.1% by weight of mixture for A.C. (40-50) and (60-70), respectively. Marshall properties results show an increasem

... Show More
Scopus (9)
Crossref (5)
Scopus Clarivate Crossref
Publication Date
Sat Dec 31 2016
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Osmotic Membrane Bioreactor for Oily Wastewater Treatment using External & Internal Configurations
...Show More Authors

The present work aims to study the treatment of oily wastewater by means of forward osmosis membrane bioreactor process. Side stream (external) configuration and submerged (internal) configuration of osmotic membrane bioreactor were performed and investigated. The experimental work for each configuration was carried out continuously over 21 days. The flux behavior of forward osmosis membrane in an osmotic membrane bioreactor (OMBR) was investigated, using NaCl as the draw solution and CTA as FO membrane. The effect of mixed liquor suspended solids (MLSS) concentration and TDS accumulation of bioreactor on water flux and membrane fouling behaviors was detected. The accumulation and rejection of nutrients in the bioreactor (Nitrate, COD,

... Show More
View Publication Preview PDF