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Investigation of Optimum Heat Flux Profile Based on the Boiling Safety Factor
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An experimental study is conducted to investigate the effect of heat flux distribution on the boiling safety factor of its cooling channel. The water is allowed to flow in a horizontal circular pipe whose outlet surface is subjected to different heat flux profiles. Four types of heat flux distribution profiles are used during experiments: (constant distribution profile, type a, triangle distribution profile with its maximum in channel center, type b, triangle distribution profile with its maximum in the channel inlet, type c, and triangle distribution profile with its maximum in the channel outlet, type d). The study is conducted using heat sources of (1000 and 2665W), water flow rates of (5, 7 and 9 lit/min). The water temperature at cooling channel inlet is kept constant at (25°C). Copper test section of (0.6 m) length (0.025m) inner diameter is used during the experiments. The electrical heater used for water heating is wrapped around the copper pipe covering (50 cm) of its length. Calibrated thermocouples are distributed along pipe surface at distances (0.1, 0.2, 0.3, 0.4 and 0.5 m) from pipe inlet to measure pipe surface temperature. The results shows that the heat source with heat flux profile of type (c) is the most reliable one from thermo-hydraulic safety point of view for both types of heat sources, as it ensures a maximum boiling safety factor (K) of (1.6, 1.7, 2) at water flow rates of (5, 7 and 9 lit/min) respectively based on maximum heat capacity of (2665 w), while the heat source with heat flux profile of type (d) which posses minimum boiling safety factors of (1, 1.2, 1.3) at water flow rates of (5, 7 and 9 lit/min) respectively based on same heat capacity value is the worst one from same point of view.

 

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Publication Date
Mon Jun 17 2019
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Ebonite linings Based on Natural and Synthetic Rubber
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 The corrosion of metals is of great economic importance. Estimates show that the quarter of the iron and the steel produced is destroyed in this way. Rubber lining has been used for severe corrosion protection because NR and certain synthetic rubbers have a basic resistance to the very corrosive chemicals particularly acids. The present work includes producing ebonite from both natural and synthetic rubbers ; therefore, the following materials were chosen to produce ebonite rubber: a) Natural rubber (NR). b) Styrene butadiene rubber (SBR). c) Nitrile rubber (NBR). d) Neoprene rubber (CR) [WRT]. The best ebonite vulcanizates are obtained in the presence of 30 Pphr sulfur, and carbon black as reinforcing filler. The relation between

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Publication Date
Thu Dec 29 2016
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Isolation and Diagnosis of Aerobic Bacteria from Patients with Respiratory Tract Infection and Partial Characterization of Their Plasmid Profile
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   In this study, the bacteria from sputum specimens of patients with respiratory tract infections were isolated in   IbnSina Teaching Hospital, Mosul city, Iraq.  The bacteria  were subjected to phenotypic and biochemical tests necessary for identification. Twenty five isolates of six different bacterial species were obtained, they are : Staphylococcus aureus, Streptococcus pneumonia, Moraxella cattarhalis, Escherichia coli, Klebsiella pnuemoniae and Pseudomona saeruginosa with ratios (64%, 12%, 8%, 8%, 4% and 4% ) respectively. The sensitivity and resistance of these isolates to 12 antibiotic were studied, where the Gentamycin appear to be more effective on most of the isolates while all the isolates showe

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Publication Date
Tue Nov 01 2016
Journal Name
International Journal Of Pharmaceutical Sciences Review And Research
A study on some variables affecting the preparation of ethyl cellulose based floating microspheres of lafutidine
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Lafutidine (LAF) a newly developed histamine H2-receptor antagonist with absorption window makes it a good candidate to be prepared as floating drug delivery system. The current study involves formulation and in- Vitro evaluation of lafutidine as floating microspheres. Different formulation variables that affect the physicochemical properties of the prepared microspheres besides to the drug release behavior were investigated. Fourteen formulas were prepared by emulsion (o/w) solvent evaporation method using Ethyl cellulose (EC) as the polymeric matrix and tween 80 (TW80) as an emulsifying agent. The prepared formulas were evaluated for their percentage buoyancy (%), Percentage yield (%) and Entrapment efficiency (EE %). The results obt

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Publication Date
Wed Sep 12 2018
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Network Performance Analysis Based on Network Simulator NS-2.
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     NS-2 is a tool to simulate networks and events that occur per packet sequentially based on time and are widely used in the research field. NS-2 comes with NAM (Network Animator) that produces a visual representation it also supports several simulation protocols. The network can be tested end-to-end. This test includes data transmission, delay, jitter, packet-loss ratio and throughput. The Performance Analysis simulates a virtual network and tests for transport layer protocols at the same time with variable data and analyzes simulation results based on the network simulator NS-2.

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Publication Date
Wed Aug 09 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Comparison of Optimum Balance Values For Different Coefficients of Spherical Aberration of Optical System Including Different Apertures
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         The optimum balance values for different coefficient of spherical aberration (third and fifth degree also focal shift) were studied, the optical system includes different apertures (circle, ellipse, square and triangle) using point spread function (PSF).       By using (Marechal) method; the minimum value of mean square of variance in wave front was founded, so we can get the maximum of central intensity according to (Strehl) criterion.

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Publication Date
Thu Oct 01 2015
Journal Name
Journal Of Nanoelectronics And Optoelectronics
Hypothetical Design of Carbon Nanotube Materials Based on [8]Circulene
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B3LYP/6-31G, DFT method was applied to hypothetical study the design of six carbon nanotube materials based on [8]circulene, through the use of cyclic polymerization of two and three molecules of [8]circulene. Optimized structures of [8]circulene have saddle-shaped. Design of six carbon nanotubes reactions were done by thermodynamically calculating (Δ S, Δ G and Δ H) and the stability of these hypothetical nanotubes depending on the value of HOMO energy level. Nanotubes obtained have the most efficient gap energy, making them potentially useful for solar cell applications.

Publication Date
Thu Feb 01 2018
Journal Name
Journal Of Pharmacy And Biological Sciences
Genetic Polymorphism of Iraqi Leishmania tropica Isolates Based on HSP70Gene
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Leishmaniasis is one of the important parasitic diseases, affecting mainly low social class people indeveloping countries, and is more prevalent and endemic in the tropical and subtropical regions of old worldand new world. Despite ofbroad distribution in Iraq,little known about the geneticcharacteristics of thecausative agents. So this study was aimed to evaluate the genetic varietyoftwo IraqiLeishmaniatropicaisolatesbased on heat shock protein gene sequence 70 (HSP70) in comparison with universal isolates recordedsequences data. After amplification and sequencing of HSP70 gene,the obtainedresults were alignment alongwith homologous Leishmania sequences retrieved from NCBI by using BLAST. The analysis results showedpresence of particular g

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Publication Date
Sat Oct 01 2022
Journal Name
Baghdad Science Journal
A Crime Data Analysis of Prediction Based on Classification Approaches
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Crime is considered as an unlawful activity of all kinds and it is punished by law. Crimes have an impact on a society's quality of life and economic development. With a large rise in crime globally, there is a necessity to analyze crime data to bring down the rate of crime. This encourages the police and people to occupy the required measures and more effectively restricting the crimes. The purpose of this research is to develop predictive models that can aid in crime pattern analysis and thus support the Boston department's crime prevention efforts. The geographical location factor has been adopted in our model, and this is due to its being an influential factor in several situations, whether it is traveling to a specific area or livin

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Publication Date
Sun Feb 03 2019
Journal Name
Iraqi Journal Of Physics
Performance of humidity sensor based on photonic crystal fiber interferometer
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Photonic Crystal Fiber Interferometers (PCFIs) are greatly used
for sensing applications. This work presents the fabrication and
characterization of a relative humidity sensor based on Mach-
Zehnder Interferometer (MZI), which operates in reflection mode.
The humidity sensor operation based on the adsorption and
desorption of water vapour at the silica-air interface within the PCF.
The fabrication of this sensor is simple, it only includes splicing and
cleaving the PCF with SMF.PCF (LMA-10) with a certain length
spliced to SMF (Corning-28).
The spectrum of PCFI exhibits good sensitivity to humidity
variations. The PCFI response is observed for a range of humidity
values from (27% RH to 85% RH), the positi

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Publication Date
Sat Apr 09 2016
Journal Name
Photonic Sensors
Parametric Analysis of NO2 Gas Sensor Based on Carbon Nanotubes
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