Preferred Language
Articles
/
ChfcbZIBVTCNdQwCG7Be
CFD Investigation of the Soldering Process for a Small Spherical PCM Made of Lead-tin Alloy
...Show More Authors

Unlike welding, soldering does not involve melting the work pieces. Soldering is a process in which two or more items are joined together by melting and putting a filler metal (solder) into the joint. Failure in the solder joint may make the system components lose their functions. Electrical wiring and electronic components are joined to devices and printed circuit boards using soldering. Soldering and brazing are both used in the assembly of musical instruments. Lead-tin alloy solder employed in the current investigation which has a diameter of 4 mm and a density of 11.0103 kg/m3 with continuous heat flux heating from the domain's left side and complete insulation on the other side. The melting of PCM was simulated using the ANSYS (Fluent) melting model. Three procedures were followed during the heating stage of the reflow process to perform the melting heat-transfer analysis. The simulation's results were recorded at regular intervals of 15 seconds. The results show melting rate increases as time proceeds. It is almost the same at the initial stages and increases in the middle and the end of the melting process. Heat transfer happens mostly through conduction during the first 0–30 seconds of the melting process, changing to natural convection as the material continues to heat up.

Scopus Crossref
View Publication
Publication Date
Sun Mar 04 2012
Journal Name
Baghdad Science Journal
Improvement of the blood characteristics of the broiler chickens by addition tryptophan acid supplement levels in ration
...Show More Authors

This study were implemented on (60) broiler chick with one day age divided into three equal groups , first one was given basal diet while group two and three given adiet contain 0.01% ,0.02% tryptophan respectively for 7 weeks . The results show that the chicks recevd the tryptophan have asigneficant increasment in hemoglobin concentration, red blood cells count, packed cell volume and increased the level of globuline concentration and lymphocyte % which mean that the addition of tryptophan improve blood picture charactores and the immunity of the broiler chickens and this evident from the good health state and decrease the mortality among birds .

View Publication Preview PDF
Crossref
Publication Date
Mon Feb 01 2021
Journal Name
Journal Of Research In Medical And Dental Science
The Effect of Adding Poloxamer Surfactant on the Penetration Depth of NaOCl and NaOH into Dentinal Tubules
...Show More Authors

Objectives: The purpose of this in vitro study was to compare the effect of adding poloxamer surfactant to irrigant solutions on the penetration de..

View Publication Preview PDF
Publication Date
Sat Jan 04 2014
Journal Name
Journal Of Materials And Chemical Engineering
The Effect of Atomic Percentage Selenium Content on the Permittivity and Polarizability of Ge1-xSex thin films
...Show More Authors

Generally the a.c. conductivity shows a power law in frequency s  ()  where the exponent s ≤ 1. As the frequency goes to zero the conductivity become frequency independent. The a.c. conductivity was studied for the Ge1-xSex thin films to see how the selenium contents affect the permittivity and the permeability for the Ge1-x Sex. The thin films prepared by thermal evaporation at room temperature and under vacuum (~2 x10-5toor) using Edward coating unit model 306A. From the relation between ln conductivity and ln w, the effect of selenium contents in Ge1-x Sex thin films on the exponent value, the relaxation time and the maximum barrier height. An algebric fitting method for circles and circular arcs was used to find the permit

... Show More
Preview PDF
Publication Date
Fri Nov 01 2019
Journal Name
Journal Of Physics: Conference Series
The Bifurcation analysis of Prey-Predator Model in The Presence of Stage Structured with Harvesting and Toxicity
...Show More Authors
Abstract<p>For a mathematical model the local bifurcation like pitchfork, transcritical and saddle node occurrence condition is defined in this paper. With the existing of toxicity and harvesting in predator and prey it consist of stage-structured. Near the positive equilibrium point of mathematical model on the Hopf bifurcation with particular emphasis it established. Near the equilibrium point E<sub>0</sub> the transcritical bifurcation occurs it is described with analysis. And it shown that at equilibrium points E<sub>1</sub> and E<sub>2</sub> happened the occurrence of saddle-node bifurcation. At each point the pitch fork bifurcation occurrence is not happened. </p> ... Show More
View Publication
Crossref (1)
Crossref
Publication Date
Sun Jun 07 2009
Journal Name
Baghdad Science Journal
Changes of the susceptibility of Staphylococcus aureus bacteria to the local therapeutic agent by using Nitrogen laser
...Show More Authors

This study involves the investigation of the effect of nitrogen laser with 337.1 nm wavelength on the sensitivity of Staphylococcus aureus bacteria by using local therapeutic due to burns. Thirty six isolate of Staphylococcus aureus bacteria were isolated from 25 patients suffering from sever burns, each isolate of bacteria was irradiated with nitrogen laser at (5, 10, 15 and 30) pulses/second repetition rates for 1, 5, 10, 20 and 30 minutes for each repetition rate. The effects of nitrogen laser on the local therapeutics sensitivity of bacteria were obtained using Kirby Baur method. Changes in the sensitivity of bacteria to local therapeutics (Tetracyclin, Chloramphenicol, Flumizin and Fucidin) occur at high repetition rate(30 pulses/seco

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sat Jul 01 2023
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Analysis of the tax policy strategy and its impact on the technical regulation of taxes (tax price)
...Show More Authors

The research aims to identify the tax policy strategy adopted in Iraq after the change of the tax system in 2003 and beyond, and then make a comparison of the two strategies on corporate data whether they are charged with progressive tax rates and after the change of the system as the tax rates became fixed, and then indicate the changes In the tax proceeds, and knowing the dimensions of the approved tax policy, is it a tax reform strategy or a strategy to attract investments.

The research started from the problem of exposure of the Iraqi tax system to several changes in the tax strategy from 2003 until now, as this led to a reflection on the technical organization of taxes, in terms of the tax exemption.And these many amendments

... Show More
View Publication Preview PDF
Publication Date
Tue Nov 08 2022
Journal Name
V. International Scientific Congress Of Pure, Applied And Technological Sciences
The effect of background vacuum pressure on the length of gas discharge plasma by using Aluminum electrodes
...Show More Authors

Length of plasma generated by dc gas discharge under different vacuum pressures was studied experimentally. The cylindrical discharge tube of length 2m was evacuated under vacuum pressure range (0.1-0.5) mbar at constant external working dc voltage 1500V. It was found that the plasma length (L) increased exponentially with increasing of background vacuum air pressure. Empirical equation has been obtained between plasma length and gas pressure by using Logistic model of curve fitting. As vacuum pressure increases the plasma length increases due to collisions, ionizations, and diffusions of electrons and ions.

Publication Date
Wed Jun 30 2021
Journal Name
Iraqi Geological Journal
The Effect of Weighting Materials on the Rheological Properties of Iraqi and Commercial Bentonite in Direct Emulsion
...Show More Authors

Numerous drilling additives and materials are used continuously because they are necessary to support and give the required properties of the drilling fluid so that to ensure the stability of the borehole. This paper aspires to evaluate the rheological properties of bentonite (montmorillonite) Trefawey as an alternative to using commercial bentonite. Monitoring and evaluating of the rheological and filtration properties were prepared. This exertion aims to focus on the effect of hematite, and barite on the rheological properties of the three aforementioned bentonite types. An improvement in the rheological properties of bentonite (montmorillonite). Trefawey was observed after adding the previous heavy materials. Hematite has by some

... Show More
View Publication
Crossref (1)
Crossref
Publication Date
Sun Jan 13 2019
Journal Name
Iraqi Journal Of Physics
The effect of short range correlation on the inelastic C2 and C4 form factors of 18O nucleus
...Show More Authors

The effect of short range correlations on the inelastic Coulomb form factors for excited +2 states (1.982, 3.919, 5.250 and 8.210MeV) and +4 states (3.553, 7.114, 8.960 and 10.310 MeV) in O18 is analyzed. This effect (which depends on the correlation parameterβ) is inserted into the ground state charge density distribution through the Jastrow type correlation function. The single particle harmonic oscillator wave function is used with an oscillator size parameter .b The parameters β and b are adjusted for each excited state separately so as to reproduce the experimental root mean square charge radius of .18O The nucleusO18 is considered as an inert core of C12 with two protons and four neutrons distributed over 212521211sdp−− activ

... Show More
View Publication Preview PDF
Crossref
Publication Date
Fri Feb 19 2016
Journal Name
International Journal Of Pure And Applied Mathematics
THE ROLE OF DYNAMIC PROGRAMMING IN THE DISTRIBUTION OF INVESTMENT ALLOCATIONS BETWEEN PRODUCTION LINES WITH AN APPLICATION
...Show More Authors

At present, the ability to promote national economy by adjusting to political, economic, and technological variables is one of the largest challenges faced by organization productivity. This challenge prompts changes in structure and line productivity, given that cash has not been invested. Thus, the management searches for investment opportunities that have achieved the optimum value of the annual increases in total output value of the production line workers in the laboratory. Therefore, the application of dynamic programming model is adopted in this study by addressing the division of investment expenditures to cope with market-dumping policy and to strive non-stop production at work.

View Publication Preview PDF
Scopus (5)
Crossref (3)
Scopus Crossref