Preferred Language
Articles
/
alkej-197
Comparisons of Mechanical Properties of sub-mm Lead Based and Lead Free Based Solder Using in Manufacturing of Printed Circuits
...Show More Authors

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.

View Publication Preview PDF
Quick Preview PDF
Publication Date
Wed Aug 31 2022
Journal Name
Iraqi Journal Of Science
Some Properties of Algebraically Paranormal Operator
...Show More Authors

Through this study, the following has been proven, if  is an algebraically paranormal operator acting on separable Hilbert space, then  satisfies the ( ) property and  is also satisfies the ( ) property for all . These results are also achieved for  ( ) property.    In addition, we prove that for a polaroid operator with finite ascent then after the property ( ) holds for  for all.

Crossref (1)
Scopus Crossref
Publication Date
Sun Jul 09 2023
Journal Name
Journal Of Engineering
Assessment of Modified - Asphalt Cement Properties
...Show More Authors

The Asphalt cement is produced as a by-product from the oil industry; the asphalt must practice further processing to control the percentage of its different ingredients so that it will be suitable for paving process. The objective of this work is to prepare different types of modified Asphalt cement using locally available additives, and subjecting the prepared modified Asphalt cement to testing procedures usually adopted for Asphalt cement, and compare the test results with the specification requirements for the modified Asphalt cement to fulfill the paving process requirements. An attempt was made to prepare the modified Asphalt cement for pavement construction in the laboratory by digesting each of the two penetration grade Asphalt c

... Show More
View Publication Preview PDF
Crossref
Publication Date
Fri Jul 01 2016
Journal Name
Journal Of Engineering
FRACTURE PROPERTIES OF LOCAL ASPALT CONCRETE
...Show More Authors

The local asphalt concrete fracture properties represented by the fracture energy, J-integral, and stress intensity factor are calculated from the results of the three point bending beam test made for pre notches beams specimens with deformation rate of 1.27 mm/min. The results revealed that the stress intensity factor has increased by more than 40% when decreasing the testing temperature 10˚C and increasing the notch depth from 5 to 30mm. The change of asphalt type and content have a limited effect of less than 6%.

 

View Publication Preview PDF
Publication Date
Wed Dec 30 2009
Journal Name
Iraqi Journal Of Physics
Optical Properties of GaN Thin Flim
...Show More Authors

GaN thin films were deposited by thermal evaporation onto
glass substrates at substrate temperature of 403 K and a thickness of
385 nm . GaN films have amorphous structure as shown in X-ray
diffraction pattern . From absorbance data within the range ( 200-
900 ) nm direct optical energy gap was calculated . Also the others
optical parameters like transmittance T, reflectance R , refractive
index n , extinction coefficient k , real dielectric constant 1 Î , and
imaginary dielectric constant 2 Î were determined . GaN films
have good absorbance and minimum transmittance in the region of
the visible light .

View Publication Preview PDF
Publication Date
Wed Dec 30 2009
Journal Name
Iraqi Journal Of Physics
Electrical Properties of ZnS Thin Films
...Show More Authors

The effect of annealing temperature (Ta) on the electrical properties like ,D.C electrical conductivity (σ DC), activation energy (Ea),A.C conductivity σa.c ,real and imaginary (ε1,ε2) of dielectric constants ,relaxation time (τ) has been measured of ZnS thin films (350 nm) in thickness which were prepared at room temperature (R.T) using thermal evaporation under vacuum . The results showed that σD.C increases while the activation energy values(Ea) decreases with increasing of annealing temperature.(Ta) from 303- 423 K .
The density of charge carriers (nH) and Hall mobility (μH) increases also with increasing of annealing temperature Hall effect measurements showed that ZnS films were n-type converted to p-type at high annealin

... Show More
View Publication Preview PDF
Publication Date
Thu Feb 01 2018
Journal Name
Journal Of Economics And Administrative Sciences
Compare between result of analysis of variance after and before use analysis covariance to Split-blocks design
...Show More Authors

This research aims to study the important of the effect of analysis of covariance manner for one of important of design for multifactor experiments, which called split-blocks experiments design (SBED) to deal the problem of extended measurements for a covariate variable or independent variable (X) with data of response variable or dependent variable Y in agricultural experiments that contribute to mislead the result when analyze data of Y only. Although analysis of covariance with discussed in experiments with common deign, but it is not found information that it is discussed with split-Blocks experiments design (SBED) to get rid of the impact a covariance variable. As part application actual field experiment conducted, begun at

... Show More
View Publication Preview PDF
Crossref
Publication Date
Tue Dec 01 2009
Journal Name
Journal Of Economics And Administrative Sciences
The importance of improved forests in Iraq and their impact on the economic and social future
...Show More Authors

عانت الغابات في العراق قصوراً واضحاً في مجال إشباع حاجة السكان لمنتجاتها الرئيسية المتمثلة بالأخشاب ومنتجاتها الثانوية المتمثلة بالأغصان والأوراق والنباتات الطبيعية والحيوانات البرية ونواتجها الأخرى، مما يتطلب التفكير بمحاولة إيجاد سبل جديدة لحل هذه المشكلة الاقتصادية المرتبطة بعنصريها الحاجة للأخشاب والأموال المخصصة لتطويرها عموماً.

لقد دمرت مساحات كبيرة من الغابات وحرقت وقطعت من

... Show More
View Publication Preview PDF
Crossref
Publication Date
Wed Jul 01 2015
Journal Name
Al–bahith Al–a'alami
Mechanisms of Social Change in the Era of Digital Communication and its Effects on the Communicative Message
...Show More Authors

When sites of new communication occurs which represents the merit of the development of communication technology which is characterized by the services of ( facebook-twiter-corapora-youtube-mass space-friendster-flicker-willnecked in addition to the direct services for viber-whatsup-telgram-and chat on) play important role in changing the infrastructure of Arabic societies which are consideredas closed and not changeable societies during near period and the significance of this study comes from the importounce of this subject which is considered as anew trend of the age on the field of media and public response and acceptance inspite of what is known about Arabic society-it doesn’t accept change-this occurance is associated with terms

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sun Sep 22 2019
Journal Name
Baghdad Science Journal
Spectral Properties of Hybrid of Rhodamine (6G) Dyes Doped Epoxy Resin Dissolved in Chloroform
...Show More Authors

            The research is dealing with the absorption and fluorescence spectra for the hybrid of  an Epoxy Resin doped with organic dye Rhodamine (R6G) of different concentrations (5*10-6, 5*10-5, 1*10-5, 1*10-4, 5*10-4) Mol/ℓ at room temperature. The Quantum efficiency Qfm, the rate of fluorescence emission Kfm (s-1), the non-radiative lifetime τfm (s), fluorescence lifetime τf and the Stokes shift were calculated. Also the energy gap (Eg) for each dye concentration was evaluated. The results showed that the maximum quantum effi

... Show More
View Publication Preview PDF
Scopus (4)
Crossref (1)
Scopus Clarivate Crossref
Publication Date
Wed Mar 10 2021
Journal Name
Baghdad Science Journal
Study the effect of fish in alternating electrical properties of copper oxide membranes CuO
...Show More Authors

In this research study the effect of fish in alternating electrical properties at room temperature copper oxide membranes and fish prepared in a manner different thermal spraying chemical on a thin glass bases and heated

View Publication Preview PDF