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Comparisons of Mechanical Properties of sub-mm Lead Based and Lead Free Based Solder Using in Manufacturing of Printed Circuits
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Abstract

This study investigates the mechanical compression properties of tin-lead and lead-free alloy spherical balls, using more than 500 samples to identify statistical variability in the properties in each alloy. Isothermal aging was done to study and compare the aging effect on the microstructure and properties.

The results showed significant elastic and plastic anisotropy of tin phase in lead-free tin based solder and that was compared with simulation using a Crystal Plasticity Finite Element (CPEF) method that has the anisotropy of Sn installed. The results and experiments were in good agreement, indicating the range of values expected with anisotropic properties.

Keywords: Lead-free solder, composite solder, and aging.

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Publication Date
Fri Jan 01 2021
Journal Name
Journal Of Engineering
A Computational Fluid Dynamics Investigation of using Large-Scale Geometric Roughness Elements in Open Channels
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The hydraulic behavior of the flow can be changed by using large-scale geometric roughness elements in open channels. This change can help in controlling erosions and sedimentations along the mainstream of the channel. Roughness elements can be large stone or concrete blocks placed at the channel's bed to impose more resistance in the bed. The geometry of the roughness elements, numbers used, and configuration are parameters that can affect the flow's hydraulic characteristics. In this paper, velocity distribution along the flume was theoretically investigated using a series of tests of T-shape roughness elements, fixed height, arranged in three different configurations, differ in the number of lines of roughness element

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Publication Date
Mon Aug 01 2011
Journal Name
Journal Of Engineering
Preservation of Required Chlorine Concentration in Baghdad Water Supply Networks using On-Site Chlorine Injection
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The chlorine concentration variation in Baghdad water networks was studied. The
chlorine data were collected from Mayoralty of Baghdad and Ministry of Environment
(MOE) for the networks for both sides of the city Karkh and Rasafa for (2008-2009). The
study of these data indicates that there are no systematic testing program .Classified GIS
maps showed that the areas far from the treatment plants have almost always low
chlorine concentration .This indicates that the problem of the low chlorine concentration
in the far areas is due to cracks of pipe along the conveyance path ,as expected. The area's
most frequently have low concentration are Al-sadir,Al-Kadhimya, and Al-Amiria . It
was found also that the chlorine c

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Publication Date
Sun Oct 01 2017
Journal Name
Journal Of Engineering
Optimization of Surface Roughness for Al-alloy in Electro-chemical Machining (ECM) using Taguchi Method
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Electro-chemical Machining is  significant  process to remove metal with using  anodic dissolution. Electro-chemical machining use to removed metal workpiece from (7025) aluminum alloy using Potassium chloride (KCl) solution .The tool used was made from copper. In this present the optimize processes input parameter use are( current, gap and electrolyte concentration) and surface roughness (Ra) as output .The experiments on electro-chemical machining with use current (30, 50, 70)A, gap (1.00, 1.25, 1.50) mm and electrolyte concentration (100, 200, 300) (g/L).  The method (ANOVA) was used to limited the large influence factors affected on surface roughness and found the current was the large influence f

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Publication Date
Thu Jun 01 2017
Journal Name
Journal Of The American Medical Directors Association
Comprehensive Literature Review of Factors Influencing Medication Safety in Nursing Homes: Using a Systems Model
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Publication Date
Mon Jun 15 2020
Journal Name
Journal Of Baghdad College Of Dentistry
Effect of different bracket types on streptococcus mutans count in orthodontic patients using fluoridated toothpaste
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Background: Plaque retention during fixed orthodontic therapy is an important cause of developing enamel demineralization. The purpose of this study was to evaluate the effect of different brackets types on the count of Streptococcus Mutans in orthodontic patients using conventional fluoridated toothpaste. Materials and Methods: Plaque samples were collected from maxillary 1st premolar teeth of twenty right handed patients (using split mouth technique) before bonding, after 48 hrs of bonding using tooth brush only, and after 2 weeks of using fluoridated toothpaste. Stainless steel bracket was bonded on right first premolar while the left one was bonded with sapphire bracket. The calculation of the Streptococcus Mutans count was done usin

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Publication Date
Mon Jun 30 2014
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Using Sonic Log to Predict Abnormal Pressure Zones in Selected Oil Wells (Western of Iraq)
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Two oil wells were tested to find the abnormal pressure zones using sonic log technique. We found that well Abu-Jir-3 and Abu-Jir-5 had an abnormal pressure zones from depth 4340 to 4520 feet and 4200 to 4600 feet, respectively. The maximum difference between obtained results and the field measured results did not exceed 2.4%.
In this paper, the formation pressures were expressed in terms of pressure gradient which sometimes reached up to twice the normal pressure gradient.
Drilling and developing such formations were dangerous and expensive.
The plotted figures showed a clear derivation from the normal trend which confirmed the existence of abnormal pressure zones.

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Publication Date
Mon Jan 01 2024
Journal Name
Baghdad Science Journal
A New Approach for Developing Spectrophotometric Determination of Phenylephrine Drug in Pure, Pharmaceutics and Serum Samples Using Sodium Periodate as Oxidizing Agent via a Green Method of CFIA/Merging Zone Technique
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     The research involved a rapid, automated and highly accurate developed CFIA/MZ technique for estimation of phenylephrine hydrochloride (PHE) in pure, dosage forms and biological sample. This method is based on oxidative coupling reaction of 2,4-dinitrophenylhydrazine (DNPH) with PHE in existence of sodium periodate as oxidizing agent in alkaline medium to form a red colored product at ʎmax )520 nm (. A flow rate of 4.3 mL.min-1 using distilled water as a carrier, the method of FIA proved to be as a sensitive and economic analytical tool for estimation of PHE.

Within the concentration range of 5-300 μg.mL-1, a calibration curve was rectilinear, where the detection limit was 3.252 μg.mL

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Publication Date
Wed Jun 10 2009
Journal Name
Iraqi Journal Of Laser
The performance of a passively Q-switched Cr:YAG4+ in an end- pumped laser system
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A characteristic study of a passively Q-switched diode pumped solid state laser system is presented in this work. For laser a comparison study for the theoretically calculated results with a simulation results using a software which calculates the Q-switched solid state laser parameters was such as energy, peak power and pulse width were performed. There was a good agreement between our theoretical calculations and the simulation values.

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Publication Date
Sun Jan 01 2017
Journal Name
المجلة القانونية العلمية المحكمة
الضمانات القانونية لتنفيذ الالتزامات الضريبية في عمل السلطة المالية في جمهورية العراق دراسة مقارنة
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Publication Date
Sun Apr 02 2006
Journal Name
Journal Of Educational And Psychological Researches
أسباب الرسوب في الكليتين المتناظرتين الادارة والاقتصاد في الجامعة المسنتصرية وجامعة بغداد ( دراسة مقارنة)
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مشكلة البحث واهميته:

نتيجة لما يشهده قطاع التربية من تغير كبير وتطور سريع, فقد اتجه تخطيط السياسة التعليمية في القطر نحو تحديد كفاءة النظام التعليمي بمختلف مراحله كونها اجزاء متداخلة في تركيب تنظيمي واحد(9: 3 ) . وذلك من اجل استمرار تطويره, وتوجيهه بما يتفق واحداث المرحلة ومتطلباتها, على اساس ان مخرجات كل مرحلة تعليمية من مراحله المتتابعة تمثل المدخلات الجديدة لمرحلة تعليمية لاحقة.

وقد حظي التعلي

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