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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
Sat Feb 27 2021
Journal Name
Journal Of Engineering
Improvement of Unconfined Compressive Strength of Soft Clay using Microbial Calcite Precipitates
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The precipitation of calcite induced via microorganisms (MICP) is a technique that has been developed as an innovative sustainable ground improvement method utilizing ureolytic bacteria to soil strengthening and stabilization. Locally isolated Bacillus Sonorensis from Iraqi soil samples were found to have high abilities in producing urease. This study aims to use the MICP technique in improving the undrained shear strength of soft clay soil using two native urease producing bacteria that help in the precipitation of calcite to increase the cementation between soil particles. Three concentrations of each of the locally prepared Bacillus sonorensis are used in this study for cementation reagent (0.25M, 0.5M, and 1M) during

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Publication Date
Fri Apr 01 2022
Journal Name
Journal Of Engineering
Prediction of Shear Strength Parameters of Gypseous Soil using Artificial Neural Networks
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The shear strength of soil is one of the most important soil properties that should be identified before any foundation design. The presence of gypseous soil exacerbates foundation problems. In this research, an approach to forecasting shear strength parameters of gypseous soils based on basic soil properties was created using Artificial Neural Networks. Two models were built to forecast the cohesion and the angle of internal friction. Nine basic soil properties were used as inputs to both models for they were considered to have the most significant impact on soil shear strength, namely: depth, gypsum content, passing sieve no.200, liquid limit, plastic limit, plasticity index, water content, dry unit weight, and initial

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Publication Date
Sun Feb 28 2021
Journal Name
Journal Of Economics And Administrative Sciences
The reality of total quality management in educational institutions and its role in achieving excellence performance
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This study is concerned with the reality of total quality management and its role in achieving the excellence performance of the employees of the Institute of Technology / Baghdad, excellence performance is described by the extent to which the organization is able to invest the effort of the human resource to achieve its Objectives by adopting the principles of Total Quality Management (TQM) according to some of its basic dimensions in proportion to the reality and Possibilities Institute, the aim is to study to know the reality of total quality management ,and indicate the levels of excellence performance in the Institute of Technology / Baghdad,

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Publication Date
Sun Jan 13 2019
Journal Name
Iraqi Journal Of Physics
Measurements of radon, thoron and their progeny concentrations using twin cup dosimeter for indoor Al-Madaan city – Baghdad – Iraq
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In this study, the activity concentrations of indoor radon, thoron
and their progeny have been measured in air for 61 different
locations of Al-Maddan city using twin cup dosimeter. Furthermore,
some useful parameters concerning the health hazards have been
estimated; working level month (WLM), annual effective dose (Eff),
and excess lung cancer per million person per year (ELC).The results
show that the values of radon gas levels in the investigated districts
varied from 56.28 to 194.43Bq/m3with an overall average value
132.96Bq/m3, while 0.313 to 1.085 for WLM with an overall average
0.740, respectively. The value of Eff and ELC have been found to
vary from 1.420 to 4.918 mSv/y with an overall average valu

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Publication Date
Wed May 01 2019
Journal Name
The Iraqi Journal For Information And Documentation Studies
The role and importance of scientific research in creating new knowledge and its impact on developing the cognitive capabilities of information and librarians and their Employees
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The research aims at identifying the importance of scientific research for researchers and in creating new knowledge، development and utilization of mental and cognitive energies and developed them with the ability to research، extrapolation، meditation and then conclusion. The information was collected by interviewing the Secretary-General of the Central Library and by distributing questionnaire forms to the (33) teaching staff of the College of Higher Education. The responses of the society were analyzed the result and the recommendations were the most important 1. Information specialist and all employees of the administrators and technicians in the centers of information sources (libraries) and in the field are considered scientific r

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Publication Date
Sun Jan 01 2023
Journal Name
E3s Web Of Conferences
Comparing the Design Alternatives Using Building Information Model (BIM) and Constructability in Iraqi Construction Projects
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The Iraqi construction industry suffers from many issues that lead to many design errors, clashes, delays and cost overruns. Therefore, applying constructability will prevent these issues from happening, as it has proven its positive effect in different projects around the world. The goal of this paper is to use building information modelling (BIM) to assess the constructability, provide the opportunities for the project stakeholders to choose the best constructable design alternative and find the affection of applying constructability on project cost. The practical side of this research consists of two parts: in the first part, 37 factors are collected from the literature review as factors that effect on constructability. After tha

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Publication Date
Mon Mar 23 2020
Journal Name
Journal Of Engineering
Diagnosing Water Problem for Asmari Reservoir in Abu Ghirab Oilfield Using Analytical and Numerical Approaches
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Asmari is the main productive reservoir in Abu Ghirab oilfield in the south-east part of Iraq. It has history production extends from 1976 up to now with several close periods. Recently, the reservoir suffers some problems in production, which are abstracted as water production rising with oil production declining in most wells. The water problem type of the field and wells is identified by using Chan's diagnostic plots (water oil ratio (WOR) and derivative water oil ratio (WOR') against time). The analytical results show that water problem is caused by the channeling due to high permeability zones, high water saturation zones, and faults or fracturing. The numerical approach is also used to study the water movement insi

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Publication Date
Fri Feb 28 2020
Journal Name
Neuroquantology
Studying the Swarm Parameters and Electron Transport Coefficients in N2– CH4 Mixtures Using BOLSIG+ Program
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Publication Date
Wed Sep 20 2017
Journal Name
Mechanical Sciences
Comparative experimental investigation and gap flow simulation in electrical discharge drilling using new electrode geometry
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Abstract. This study presents experimental and numerical investigation on the effectiveness of electrode geometry on flushing and debris removal in Electrical Discharge Drilling (EDD) process. A new electrode geometry, namely side-cut electrode, was designed and manufactured based on circular electrode geometry. Several drilling operations were performed on stainless steel 304 using rotary tubular electrodes with circular and side-cut geometries. Drilling performance was characterized by Material Removal Rate (MRR), Electrode Wear Rate (EWR), and Tool Wear Ratio (TWR). Dimensional features and surface quality of drilled holes were evaluated based on Overcut (OC), Hole Depth (HD), and Surface Roughness (SR). Three-dimensional

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Publication Date
Fri Mar 27 2020
Journal Name
Solid State Technology
Seepage and Slope Stability Analysis for Hemrin Earth Dam in Iraq Using Geo-Studio Software
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