Preferred Language
Articles
/
alkej-486
'Influence of Draft Tube Diameter on Operation Behavior of Air Lift Loop Reactors

The ratio of draft tube to reactor diameters is of decisive importance for the operation behavior of air lift loop reactors. The influence of draft tube geometry was investigated with respect to oxygen mass transfer and mixing time. The diameter ratio was varied between 0.33 and 0.80. The measurements were performed in two loop reactors with liquid capacities of 11.775 and 26.49 liters using aqueous with solutions of different coalescence behavior. The results show that there is no single diameter ratio which would produce most favorable conditions for the two process parameters. With respect to the more important requirements of aerobic cultures, i.e high oxygen mass transfer and efficient mixing, a diameter ratio between 0.5 and 0.6 is recommended. If high liquid velocities in the draft tube are required a ratio of 0.6 should be used.

View Publication Preview PDF
Quick Preview PDF
Publication Date
Mon Dec 18 2017
Journal Name
Al-khwarizmi Engineering Journal
Effect of Magnesium Addition on Corrosion Resistance of Aluminum -17%Silicon Alloy

The electrochemical behavior of Al-17%Si alloy is investigated in 3.5wt% NaCl solution. Many alloys with addition of the different wt% magnesium metal of  1wt%, 2%, 3wt% ,4.5wt% ,and 9wt% were prepared by gravity die casting . The microstructures of prepared alloys were examined by optical and SEM microscopes. Corrosion behavior was investigated by using potentiostat instrument under static potentials test and corrosion current was recorded to determine corrosion resistance of all prepared samples. It was found that the addition of Mg metal improves the corrosion resistance of Al-17%Si alloy in 3.5%NaCl solution. The alloy containing 1%Mg shows less corrosion rate than the others while the alloys containing 4.5%Mg, 9%Mg content have

... Show More
Crossref (1)
Crossref
View Publication Preview PDF
Publication Date
Thu Dec 01 2011
Journal Name
Journal Of Economics And Administrative Sciences
Measurement of Impact of Banking System Development on Economic Growth in Iraq

At the heart of every robust economy is a vital banking system. The functional banking system can effectively perform several functions such as mobilizing savings, allocating credit, monitoring managers, transforming risks, and facilitating the financial transactions. This paper aims to measure the impact of banking system development on economic growth in Iraq. Credit to private sector divided by GDP used as a proxy of banking development. Real per capita GDP used as a proxy of economic growth. By using Autoregressive Distributed Lag (ARDL) model, the paper finds that the undeveloped Iraqi banking system could not promote economic growth in the country. Therefore, a variety of policies need to be taken to spur the role of bankin

... Show More
Crossref
View Publication Preview PDF
Publication Date
Sun Jun 30 2013
Journal Name
Al-khwarizmi Engineering Journal
Effects of Different Types of Fillers on Dry Wear Characteristics of Carbon-Epoxy Composite

Experimental investigations had been done in this research to demonstrate the effect of carbon fiber and Ceramic fillers contents on the tribological behaviour of (15% volume fraction) carbon-epoxy composite system under varying volume fraction, load, time and sliding distance. The wear resistance were investigated according to ASTM G99-05standard using pin on disc machine to present the composite tribological behaviour. The influence of three ceramic fillers, granite, perlite and calcium carbonate (CaCO3), on the wear of the carbon fabric reinforced epoxy composites under dry sliding conditions has been investigated. The effect of variants in volume fraction, applied load, time and sliding distance on the wear behaviour of po

... Show More
View Publication Preview PDF
Publication Date
Tue Jun 14 2005
Journal Name
Iraqi Journal Of Laser
Bending Effect on the Single Mode Optical Fibers

Bending effects on the transmission of optical signal are investigated on a single mode
optical fiber (SMOF) of 10 m length, core radius of 5 μm and optical refractive index difference
0.003. The bending radii (R) were between 0.08 and 0.0015 m. A great decrease in the amplitude is
shown for radii below 0.01 m. Sudden break down occurs for radii less than 0.0015 m. Birefringence
(B) is difficult to measure for long fibers. Meanwhile, B was found by comparing with calibrated
fiber of the same properties but of length of 0.075 m. The results show an increase in propagation
constant (Δβ) and the decrease in beat length (Lb), and show that bending decreases the critical radius
of curvature (Rc) related to B. The chang

... Show More
View Publication Preview PDF
Publication Date
Tue Sep 18 2018
Journal Name
Water
A Systematic Operation Program of a Hydropower Plant Based on Minimizing the Principal Stress: Haditha Dam Case Study

Dam operation and management have become more complex recently because of the need for considering hydraulic structure sustainability and environmental protect on. An Earthfill dam that includes a powerhouse system is considered as a significant multipurpose hydraulic structure. Understanding the effects of running hydropower plant turbines on the dam body is one of the major safety concerns for earthfill dams. In this research, dynamic analysis of earthfill dam, integrated with a hydropower plant system containing six vertical Kaplan turbines (i.e., Haditha dam), is investigated. In the first stage of the study, ANSYS-CFX was used to represent one vertical Kaplan turbine unit by designing a three-dimensional (3-D) finite element (F

... Show More
Scopus (10)
Crossref (6)
Scopus Clarivate Crossref
View Publication
Publication Date
Mon Mar 15 2021
Journal Name
Al-academy
Semantic Operation of Place in the Legendary Movie: حيدر وسم صالح

Place is considered one of the important artistic elements in the movie through which the events occur in different arts and literatures and with its absence there isn’t any that can initiate events. Place is important for the things that we recognize, and the first fact in cinema is the place which can't be dispensed with on the level of the film or scene or cinematic shot that can't be emptied from its spatial content. The characters are always there in a place occupying some space of it, despite that it is not merely a container for the event cinematically. The researcher views the importance of discovering and observing them in this research which is divided into four chapters as follows: (theoretical framework) which includes the

... Show More
Crossref
View Publication Preview PDF
Publication Date
Fri Oct 01 2010
Journal Name
2010 Ieee Symposium On Industrial Electronics And Applications (isiea)
Scopus (6)
Crossref (3)
Scopus Crossref
View Publication
Publication Date
Sun Oct 02 2011
Journal Name
Journal Of The Faculty Of Medicine Baghdad
The effect of topical administration of sildenafil in acute ocular hypertension model in rabbits.

Background: Nitric oxide ( NO) is a physiological mediator of many processes in the eye including regulation of aqueous humor dynamics. Compounds acting via NO dependent mechanisms may enhance aqueous humor outflow and reduce intraocular pressure (IOP) .
Objective: Sildenafil a cGMP specific phosphodiesterase 5inhibitor that potentiates NO production and increases cyclic GMP is tested in this study for its effects on intraocular pressure in an acute ocular hypertension model in rabbits.
Materials and methods: Newzealand albino rabbits of either sex weighing 2–2.5 Kg , were used in this study. Sildenafil was prepared in a vehicle of phosphate buffer and diluted to the required strength of 0.5%. Intraocular pressure (IOP ) was meas

... Show More
Crossref (1)
Crossref
View Publication Preview PDF
Publication Date
Sun Nov 01 2020
Journal Name
Iraqi Journal Of Laser
The Effect of the Concentration of Colloidal Silver Nanoparticles on Optical Limiting Reliability

The effect of the concentration of the colloidal nanomaterial on their optical limiting behavior is reported in this paper. The colloids of sliver nanoparticles in deionized water were chemically prepared for the two concentrations (31 ppm and 11ppm). Two cw lasers (473 nm Blue DPSS laser and 532 nm Nd:YAG laser) are used to compare the optical limiting performance for the samples. UV–visible spectrophotometer, transmission electron microscope (TEM) and Fourier Transformation Infrared Spectrometer (FTIR) were used to obtain the characteristics of the sample. The nonlinear refractive index was calculated to be in the order of 10-9 cm2/W. The results demonstrate that the observed limiting response is significant for 532nm. In addition, t

... Show More
View Publication Preview PDF
Publication Date
Sat Jul 01 2023
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Analyzing impact of competitive dimensions on the efficiency of e-learning: دراسه استطلاعيه

The aim of this research is to diagnose the impact of competitive dimensions represented by quality, cost, time, flexibility on the efficiency of e-learning, The research adopted the descriptive analytical method by identifying the impact of these dimensions on the efficiency of e-learning, as well as the use of the statistical method for the purpose of eliciting results. The research concluded that there is an impact of the competitive dimensions on the efficiency of e-learning, as it has been proven that the special models for each of the research hypotheses are statistically significant and at a level of significance of 5%, and that each of these dimensions has a positive impact on the dependent variable, and the research recommended

... Show More
View Publication Preview PDF