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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
Sun Sep 30 2012
Journal Name
Al-hiqouq
The Maintenance Contract – A Comparative Study with Islamic Jurisprudence
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Contemporary life is racing against time in its temptations and variables, and it has become shaped and changed in an amazing way in its various aspects and fields. This was facilitated by intellectual and scientific communication between civilizations, and the rapid progression in successive inventions and discoveries in the fields of science and arts of knowledge. This contributed to a great economic and commercial renaissance. Then, these economic developments entered the world into a very strong competition, which forced producers to calculate all production costs, to reach the highest profits by reducing the price of the produced commodity on the one hand, and achieving quality in appearance (especially) on the other hand. Since the ma

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Publication Date
Fri Sep 02 2022
Journal Name
مجلة العلوم القانونية
مدى جواز الفسخ الجزئي للعقد ( دراسة مقارنة)
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في العقود الملزمة للجانبين اذا لم ينفذ احد المتعاقدين التزامه تنفيذا كليا فانه يجوز للمتعاقد الاخر ان يطلب من المحكمة فسخ العقد فسخا كليا ، الا انه قد يقتصر عدم التنفيذ على جزء من التزامه فعندئذ يثار التساؤل الاتي: هل يمكن فسخ العقد فسخا جزئيا ؟ الملاحظ ان هنالك خلافا فقهيا وقضائيا كبيرا حول جواز الفسخ الجزئي ، فالبعض يجيز الحكم بالفسخ الجزئي ، والبعض الاخر لا يجيز الحكم بالفسخ الجزئي، وقد انتهينا الى القول بع

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Publication Date
Sat Dec 01 2012
Journal Name
Journal Of Economics And Administrative Sciences
Comparing Several Nonlinear Estimators for Regression Function
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The aim of this paper is to estimate a nonlinear regression function of the Export of the crude oil Saudi (in Million Barrels) as a function of the number of discovered fields.

 Through studying the behavior of the data we show that its behavior was not followed a linear pattern or can put it in a known form so far there was no possibility to see a general trend resulting from such exports.

We use different nonlinear estimators to estimate a regression function, Local linear estimator, Semi-parametric as well as an artificial neural network estimator (ANN).

The results proved that the (ANN) estimator is the best nonlinear estimator am

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Publication Date
Fri Nov 15 2024
Journal Name
مجلة الاستاذ للعلوم الانسانية والاجتماعية
التباين النقدي بين المفسرين والمستشرقين – دراسة- مقارنة-
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لظهور كثير من الاراء التفسيرية والنقدية والتي تباينت في كثير من الاحيان وبخاصة من المفسرين والمستشرقين لاختلاف المشارب الفكرية لكلا الفريقين وهو ما تطلب تاصيلا لعملية النقد والمقارنة بين المنهجين

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Publication Date
Sun Jun 30 2013
Journal Name
Al-khwarizmi Engineering Journal
Drilling of FR-4 Composite Materials Using Single Pulse of Nd:YAG Laser
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Laser drilling is capable of producing small, precisely positioned holes with high degree of reproductively. In this paper , IR millisecond Nd:YAG single pulsed laser was used to determine the effect of laser parameters on the drilled hole of the glass - fiber reinforced epoxy composite FR-4 sample of 2 mm in thickness . The type of laser source was GSI lumonics JK760TR Series laser 1.064μm system in a CNC cabin. The JK760TR series has a 0.3-50ms pulse length and a maximum repetition rate 500Hz with an average power of 600W. The investigation of single pulse laser drilling in this paper was based on theoretical and experimental solutions. In single pulse technique, the investigation included focal plane position fpp, pulse shap

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Publication Date
Wed Dec 13 2017
Journal Name
Al-khwarizmi Engineering Journal
Experimental Investigations Performance for (VCC) Using 2-Way (PFCV) Type (2FRE)
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In modern hydraulic control systems, the trend in hydraulic power applications is to improve efficiency and performance. “Proportional valve” is generally applied to pressure, flow and directional-control valves which continuously convert a variable input signal into a smooth and proportional hydraulic output signal. It creates a variable resistance (orifice) upstream and downstream of a hydraulic actuator, and is meter in/meter out circuit and hence pressure drop, and power losses are inevitable. If velocity (position) feedback is used, flow pattern control is possible. Without aforementioned flow pattern, control is very “loose” and relies on “visual” feed back by the operator. At this point, we should examine how this valv

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Publication Date
Sun Nov 19 2017
Journal Name
Iraqi Journal Of Laser
Sulfur Hexafluoride (SF6) Trace Gas Sensing using Modulated CO2 Laser Beam
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Photonic Crystal Fiber Interferometers (PCFIs) are widely used for sensing applications. This work presents the fabrication and the characterization of a relative humidity sensor based on a polymer-coated photonic crystal fiber that operates in a Mach- Zehnder Interferometer (MZI) transmission mode. The fabrication of the sensor involved splicing a short (1 cm) length of Photonic Crystal Fiber (PCF) between two single-mode fibers (SMF). It was then coated with a layer of agarose solution. Experimental results showed that a high humidity sensitivity of 29.37 pm/%RH was achieved within a measurement range of 27–95%RH. The sensor also showed good repeatability, small size, measurement accuracy and wide humidity range. The RH sensitivity o

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Publication Date
Sun Mar 18 2018
Journal Name
Https://www.iasj.net/iasj/article/170012#:~:text=al.qadisiya%20journal%20for%20the%20sciences%20of%20physical%20education
The Effect Of Using Two Strategies For Active Learning ( Jigsaw Strategy & Problems Solving) In Learning Some Balanced Beam's Skills In Artistic Gymnastics
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The aim of this study to identify the effect of using two strategies for active learning ( Jigsaw Strategy & Problems Solving) in learning some balanced beam's skills in artistic gymnastics for women , as well as to identify the best of the three methods (jigsaw strategy , problems solving and the traditional method) in learning some skills balance beam , the research has used the experimental methodology, and the subject included the students of the college of Physical Education and Sports Sciences / University of Baghdad / third grade and by the lot was selected (10) students for each group of groups Search three and The statistical package for social sciences (SPSS) was used means, the standard deviation and the (T.test), the one way a n

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Publication Date
Tue Dec 01 2015
Journal Name
Journal Of Economics And Administrative Sciences
The Evaluation of Information Security Management System in the Iraqi Commission for Computers and Informatics according to the International Standard (ISO 27001: 2013)
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    The current research included (the evaluation of Information Security Management System on according to international standard (ISO / IEC 27001: 2013) in Iraqi Commission for Computers and Informatics), for the development of an administrative system for information security is considered a priority in the present day, and in the light of the organizations  dependence on computers and information technology in work and communication  with others. The international legitimacy (represented by the  International Organization for standardization (ISO)) remains the basis for matching and commitment and the importance of the application of information Security Management System accordi

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Publication Date
Mon Oct 01 2018
Journal Name
Iraqi Journal Of Physics
Optical properties for prepared polyvinyl alcohol/ polyaniline/ ZnO nanocomposites
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The optical energy gap and optical constants such as the reflective index, dielectric constant have been evaluated due to The optical transmission and UV-VIS absorption spectra have been recorded in the wavelength (200 - 1100 nm) for PVA/PANI polymer blends and PVA/PANI/ZnO nanocomposites with different concentrations of ZnO (0.02, 0.05, 0.07, 0.1and 0.2) wt %. The results indicate that the materials have allowed direct transition. The reflection index and dielectric constant are increase with wavelength

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