Preferred Language
Articles
/
alkej-519
Investigation of Thermal Stress Distribution in Laser Spot Welding Process
...Show More Authors

The objective of this paper was to study the laser spot welding process of low carbon steel sheet. The investigations were based on analytical and finite element analyses. The analytical analysis was focused on a consistent set of equations representing interaction of the laser beam with materials. The numerical analysis based on 3-D finite element analysis of heat flow during laser spot welding taken into account the temperature dependence of the physical properties and latent heat of transformations using ANSYS code V.10.0 to simulate the laser welding process. The effect of laser operating parameters on the results of the temperature profile were studied in addition to the effect on thermal stresses  and dimensions of the laser welded workpiece which showed good correlations between analytical and numerical results. It was found that the temperature gradients during laser welding are usually very large and it was viewed that very high temperature at the center of the workpiece, and is decreased very significantly as propagating along the radial direction. Also it found that the thermal residual stresses around the laser spot due to plastic strains were very small and localized within 1.0 mm range. It is concluded that the laser welding process is effective to reduce the welding residual stress. The stresses along the lateral direction of the workpiece changed from compression at the spot under the laser beam and tension away from the spot at the end of welding to tension at the spot under the laser beam and compression away from the spot when it cooled, which are in a good agreement with the published results.

   

View Publication Preview PDF
Quick Preview PDF
Publication Date
Sun Apr 01 2018
Journal Name
Journal Of Educational And Psychological Researches
Relationship sensitivity to stress with positive mood Among Educational Counselors
...Show More Authors

The study aimed to examine the sensitivity to stress and its relation to positive mood among educational supervisors. The researcher used the descriptive approach as more an appropriate method for the current study. The sample is composed of (200) educational supervisor. To collect study data, two scales have been used: one scale to measure the sensitivity to stress and the other to measure the positive mood. The results indicated that a high level of sensitivity to stress with low level of positive mood among educational supervisors, sensitivity to stress showed significant differences among the sample regarding to major. There is no correlation between sensitivity to stress and positive mood, and finally, there are no significant diffe

... Show More
View Publication Preview PDF
Publication Date
Mon Mar 28 2022
Journal Name
The Open Dentistry Journal
Depression, Anxiety and Stress Among Dentists During COVID-19 Lockdown
...Show More Authors
Introduction:

The objective of this study was to investigate the levels of depression, anxiety, and stress among dentists during covid-19 lockdown and to investigate the relationship between stress and each mental health state.

Methods:

A cross-sectional survey on 269 dentists was conducted using DASS-21 and PHQ-9 questionnaires. Bivariate and multivariate models were constructed and the odds ratio (OR) was calculated to assess the strength of the association between an independent categorical variable and the outcome.

Results and Discussion:

Being unsatisfied with the job was as

... Show More
View Publication
Scopus (6)
Crossref (5)
Scopus Clarivate Crossref
Publication Date
Sun Dec 01 2019
Journal Name
Baghdad Science Journal
Thermodynamic Investigation of Partially Purified Paraoxonase in the Sera of Healthy Pregnant Women Compared to Women with Pregnancy Complication
...Show More Authors

The thermodynamic constanting of “crude and partially purified” Paraxonase(PON) was evaluated in the sera of “healthy and ectopic” pregnant women in order to characterize the reaction of PON with diethyl para-nitro phenyl phosphate as substrate.This study was performed on (17) women with ectopic pregnancy (EP) whose age between (25-55) years  and (25) normal pregnant women with  a mean age of (25 -55) years as  a control group . Samples were collected from the Medical City, AL-Yarmook and Fatema AL-Zahraa hospitals during the period from Sep.2011 to April 2012.The study included the evaluation  of “paraxonase activity, specific activity and total protein” in the (crude and partially purified) sera of EP pa

... Show More
View Publication Preview PDF
Scopus (1)
Scopus Clarivate Crossref
Publication Date
Sun Dec 06 2009
Journal Name
Baghdad Science Journal
Best estimation for the Reliability of 2-parameter Weibull Distribution
...Show More Authors

This Research Tries To Investigate The Problem Of Estimating The Reliability Of Two Parameter Weibull Distribution,By Using Maximum Likelihood Method, And White Method. The Comparison Is done Through Simulation Process Depending On Three Choices Of Models (?=0.8 , ß=0.9) , (?=1.2 , ß=1.5) and (?=2.5 , ß=2). And Sample Size n=10 , 70, 150 We Use the Statistical Criterion Based On the Mean Square Error (MSE) For Comparison Amongst The Methods.

View Publication Preview PDF
Crossref
Publication Date
Sun Sep 22 2019
Journal Name
Baghdad Science Journal
Estimation of Survival Function for Rayleigh Distribution by Ranking function:-
...Show More Authors

In this article, performing and deriving te probability density function for Rayleigh distribution is done by using ordinary least squares estimator method and Rank set estimator method. Then creating interval for scale parameter of Rayleigh distribution. Anew method using   is used for fuzzy scale parameter. After that creating the survival and hazard functions for two ranking functions are conducted to show which one is beast.

View Publication Preview PDF
Scopus (5)
Crossref (2)
Scopus Clarivate Crossref
Publication Date
Wed Nov 22 2017
Journal Name
Farm Machinery And Processes Management In Sustainable Agriculture, Ix International Scientific Symposium
TESTING THE UNIFORMITY OF SPRAY DISTRIBUTION UNDER DIFFERENT APPLICATION PARAMETERS
...Show More Authors

View Publication
Crossref (4)
Clarivate Crossref
Publication Date
Sun Jan 02 2011
Journal Name
Education College Journal/al-mustansiriyah
Double Stage Shrinkage Estimators of Two Parameters Generalized Rayleigh Distribution
...Show More Authors

Publication Date
Sun Mar 01 2015
Journal Name
Journal Of Engineering
Experimental Study of Interior Temperature Distribution Inside Parked Automobile Cabin
...Show More Authors

Temperature inside the vehicle cabin is very important to provide comfortable conditions to the car passengers. Temperature inside the cabin will be increased, when the car is left or parked directly under the sunlight. Experimental studies were performed in Baghdad, Iraq (33.3 oN, 44.4 oE) to investigate the effects of solar radiation on car cabin components (dashboard, steering wheel, seat, and inside air). The test vehicle was oriented to face south to ensure maximum (thermal) sun load on the front windscreen. Six different parking conditions were investigated. A suggested car cover was examined experimentally. The measurements were recorded for clear sky summer days started at 8 A.M. till 5 P.M.

... Show More
View Publication Preview PDF
Publication Date
Wed Sep 01 2021
Journal Name
Journal Of Physics: Conference Series
Theory and applications of Marshall Olkin Marshall Olkin Weibull distribution
...Show More Authors
Abstract<p>In probability theory generalizing distribution is an important area. Several distributions are inappropriate for data modeling, either symmetrical, semi-symmetrical, or heavily skewed. In this paper, a new compound distribution with four parameters called Marshall Olkin Marshall Olkin Weibull (MOMOWe) is introduced. Several important statistical properties of new distribution were studied and examined. The estimation of unknown four parameters was carried out according to the maximum likelihood estimation method. The flexibility of MOMOWe distribution is demonstrated by the adoption of two real datasets (semi-symmetric and right-skewed) with different information fitting criteria. Su</p> ... Show More
View Publication
Scopus (11)
Crossref (10)
Scopus Crossref
Publication Date
Sat Jan 01 2022
Journal Name
Technologies And Materials For Renewable Energy, Environment And Sustainability: Tmrees21gr
Effect of non-thermal plasma by FE-DBD scheme on lipids in blood in vivo study
...Show More Authors

This study illustrates the impact of non-thermal plasma (Cold Atmospheric Plasma CAP) on the lipids blood, the study in vivo. The lipids are (cholesterol, HDL-Cholesterol, LDL-Cholesterol and triglyceride) are tested. (FE-DBD) scheme of probe diameter 4cm is used for this purpose, and the output voltage ranged from (0-20) kV with variable frequency (0-30) kHz. The effect of non-thermal atmospheric plasma on lipids were studied with different exposure durations (20,30) sec. As a result, the longer plasma exposure duration decreases more lipids in blood.

View Publication
Scopus Crossref