Vol.6, No. 2 (2010)

 

Al-Khwarizmi Engineering Journal,

 

Vol.6, No. 2 (2010)

 

No. Author Name  Title Abstract Full Text
1

Kadhim H. Ghlaim

Hatem R. Waseem

Vibration Characteristics Oblate Shell "With and Without Framed Structure"

This paper presents the results of investigating the vibrational characteristics of oblate dish with and without framed structure. A finite element method, was applied to the dynamic analysis of oblate spheroidal shell. Different types of elements were considered in one dimension and two dimensions. It was found that the natural frequencies of oblate shells had two types of behavior against increasing the shell thickness and eccentricity, which are the membrane mode and bending mode –Since – the membrane modes natural frequencies tend to increase with the increasing the eccentricity of oblate, while the bending modes natural frequencies decrease with the increasing the eccentricity till reach the optimum eccentricity. Full Text
2

Miqdam T. Chaichan

Qahtan A. Abass

Study of NOx Emissions of S.I. Engine Fueled with Different Kinds of Hydrocarbon Fuels and Hydrogen

Liquefied petroleum gas (LPG), Natural gas (NG) and hydrogen were used to operate spark ignition internal combustion engine Ricardo E6, to compare NOx emissions emitted from the engine, with that emitted from engine fueled with gasoline as a fuel.

The study was done when engine operated at HUCR for gasoline, compared with its operation at HUCR for each fuel. Compression ratio, equivalence ratio and spark timing were studied at constant speed 25rps.

The results appeared that NOx concentrations will be at maximum value in the lean side near the stoichiometric ratio, and reduced with moving away from this ratio for mixture at both sides, these concentrations were at its highest value when hydrogen used at CR=8:1, and got near to each other for the three hydrocarbon fuels used in the study, when the engine operated at HUCR for each fuel, but still hydrogen had maximum value, the main variable affect these concentrations was spark timing.

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3

Ali Abdul-Rahman Al-Azzi

Laith S. S. Al-Kuffe
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. Full Text
4

Nada S. Ahmed Zeki

Maha H. Al-Hassani

Haider A. Al-Jendeel

Kinetic Study of Esterification Reaction

The Esterification kinetics of acetic acid with ethanol in the presence of sulfuric acid as a homogenous catalyst was studied with isothermal batch experiments at 50-60°C and at a different molar ratio of ethanol to acetic acid [EtOH/Ac]. Investigation of kinetics of the reaction indicated that the low of [EtOH/Ac] molar ratio is favored for esterification reaction, this is due to the reaction is catalyzed by acid. The maximum conversion, approximately 80% was obtained at 60°C for molar ratio of 10 EtOH/Ac. It was found that increasing temperature of the reaction, increases the rate constant and conversion at a certain mole ratio, that is due to the esterification is exothermic. Full Text
5

Aqeel S. Fadhil

Anwaar A. Al-Dergazly

Ziad T. Al-Dahan

355nm Wavelength Generation of Nd:YAG Laser Using Olive Oil

      This project introduces a prospective material for photonic laser applications. The material is olive oil which is classified as organic compound, having a good nonlinear optical properties candidate to be used in photonic applications. A high purity sample of olive oil has been used. The theoretical calculation to generate third harmonic wave using olive oil has been determine using MATLAB program. THG (λ=355nm) intensity has been determined at two cases of sample thicknesses 1mm and 10mm. The minimum threshold incident intensity to obtain THG intensity are equal Iω=7530 mW/cm2 at L=1mm and Iω= 6220 mW/cm2 at L=10mm. The possibility of generation of third harmonic in olive oil inside the cuvette has been experimented using different powers (90-120) mW of CW Nd:YAG laser. The signal of third harmonic generation has been detected using UV-340 Light Meter.

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6 Noor K. Muhsin

Comparison of the RLS and LMS Algorithms to Remove Power Line Interference Noise from ECG Signal

Biomedical signal such as ECG is extremely important in the diagnosis of patients and is commonly recorded with a noise. Many different kinds of noise exist in biomedical environment such as Power Line Interference Noise (PLIN). Adaptive filtering is selected to contend with these defects, the adaptive filters can adjust the filter coefficient with the given filter order. The objectives of this paper are: first an application of the Least Mean Square (LMS) algorithm, Second is an application of the Recursive Least Square (RLS) algorithm to remove the PLIN. The LMS and RLS algorithms of the adaptive filter were proposed to adapt the filter order and the filter coefficients simultaneously, the performance of existing LMS algorithm of the adaptive filters cause completely removing of the PLIN comparing with the RLS algorithm that reducing the noise level only. Full Text
7

Yarub O. Naji Al-azzawi

Ra'ad K. Mohammed Al-Duleimi

Enhancement of Hoisting System Performance

In this paper it is required to enhance the performance of a mechanical system (here: a Hoisting System) where it is preferred to lift a different payloads with approximately the same speed of lifting and keeping at the same time the good performance, and this of course needs some intelligence of the system which will be responsible on measuring the present load and taking into account the speed and performance desired in order to achieve the requirements or the criteria. The process therefore is a Mechatronics System design which includes a measuring system, a control or automation technique, and an actuating system. The criteria built here in this research using a given Hoist system's characteristics and parameters and changing one of these parameters by the actuator depending on load value (i.e. making a calibration with which there will be a given value of the intentional parameter at which the speed and performance reach the requirements to any load value). Full Text
8 Bassam F. Al-Bassam

Land Use/Cover Change Analysis Using Remote Sensing Data: A Case Study, Zhengzhou Area, Henan Province, China

In the last two decades, arid and semi-arid regions of China suffered rapid changes in the Land Use/Cover Change (LUCC) due to increasing demand on food, resulting from growing population. In the process of this study, we established the land use/cover classification in addition to remote sensing characteristics. This was done by analysis of the dynamics of (LUCC) in Zhengzhou area for the period 1988-2006. Interpretation of a laminar extraction technique was implied in the identification of typical attributes of land use/cover types. A prominent result of the study indicates a gradual development in urbanization giving a gradual reduction in crop field area, due to the progressive economy in Zhengzhou. The results also reflect degradation of land quality inferred from the decline in yield capacity and significant degeneration. Full Text
9

Mumtaz Mohammed Ali AL-Mukhtar

Software Engineering-Based Design for a Bayesian Spam Filter

The rapid spread and the easy availability of a free e-mail service have made it the medium of choice for the sending of unsolicited advertising and bulk e-mail in general. These messages, known as junk e-mail or spam mail, are an increasing problem to both Internet users and Internet service providers (ISPs).

The research resolves one aspect of the spam problem by developing an appropriate filter for the e-mail client. The proposed filter is a combination of three forms of filters: Whitelist, Blacklist, and a Bayesian filter. Whitelist-based filter only accepts e-mails from known addresses. Blacklist filter blocks e-mails from addresses known to send out spam. Bayesian content-based filter makes estimations of spam probability based on the text and filters messages based on a pre-selected threshold.

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    Hind Basil Al-Atraqji            Hanaa Arer Al.Kaisy  Study the Structure Properties of Semiconductor Film Multilayered      In this research was study the effect of increasing the number of layers of the semiconductor films as PbS on the average grain sizes and illustrate the relationship between the increase in the average grain size and thickness of the membrane, and membrane was prepared using the easy and simple and does not need the complexity of which is that the chemical bath , and from an X-ray diffraction found that the material and the installation of a random cubic and when increasing the number of layers deposited note the emergence of a number of vertices of a substance and PbS at different levels but the level is more severe (200) as well as the value is calculated optical energy gap and found to be not affected by increase thickness and from this value can be determined  the  applications of semiconductor materials and elected on the basis of Article absorbed optical radiation that incident on them. Full Text
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