Preferred Language
Articles
/
alkej-545
Simulation of Temperature Distribution in TIG Spot Welds of (Al-Mg) Alloy Using Finite Element Method
...Show More Authors

      This research concern to analyse and simulate the temperature distribution in the spot welding joints using tungsten arc welding shielded with inert gas (TIG Spot) for the aluminum-magnesium alloy type  (5052-O).

      The effect of and the quantity of the heat input that enter the weld zone has been investigated welding current, welding time and arc length on temperature distribution. The finite element method (by utilizing programme ANSYS 5.4) is presented  the temperature distribution in a circular weld pool and the weld pool penetration (depth of welding) through the top sheet ,across the interface into the lower sheet forming a weld spot.                                                                                                     

      A three dimensional (3-D) model has been constructed to study the temperature distribution and the depth or penetration of the weld spot. The results showed that the weld zone and heat affected zone (HAZ) suffer from high temperature variation caused by severe thermal cycle. The temperature reaches the highest value of the melt metal at the weld spot 698°C at weld current 130 Amp, weld time 6 sec and arc length 1.6 mm, then drops further away from the weld spot in the direction  the base metal.

      Figuers were plotted to explain the results and to show the temperature distribution and its value in the weld spot  and heat effected zone.

 

View Publication Preview PDF
Quick Preview PDF
Publication Date
Tue Dec 19 2017
Journal Name
Al-khwarizmi Engineering Journal
Prediction of Reaction Kinetic of Al- Doura Heavy Naphtha Reforming Process Using Genetic Algorithm
...Show More Authors

In this study, genetic algorithm was used to predict the reaction kinetics of Iraqi heavy naphtha catalytic reforming process located in Al-Doura refinery in Baghdad.  One-dimensional steady state model was derived to describe commercial catalytic reforming unit consisting of four catalytic reforming reactors in series process.

The experimental information (Reformate composition and output temperature) for each four reactors collected at different operating conditions was used to predict the parameters of the proposed kinetic model. The kinetic model involving 24 components, 1 to 11 carbon atoms for paraffins and 6 to 11 carbon atom for naphthenes and aromatics with 71 reactions. The pre-exponential Arrhenius constants and a

... Show More
View Publication Preview PDF
Publication Date
Wed Oct 01 2014
Journal Name
Journal Of Economics And Administrative Sciences
ON DISCRETE WEIBULL DISTRIBUTION
...Show More Authors

Most of the Weibull models studied in the literature were appropriate for modelling a continuous random variable which assumes the variable takes on real values over the interval [0,∞]. One of the new studies in statistics is when the variables take on discrete values. The idea was first introduced by Nakagawa and Osaki, as they introduced discrete Weibull distribution with two shape parameters q and β where      0 < q < 1 and b > 0. Weibull models for modelling discrete random variables assume only non-negative integer values. Such models are useful for modelling for example; the number of cycles to failure when components are subjected to cyclical loading. Discrete Weibull models can be obta

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Sun Jun 01 2008
Journal Name
Journal Of Economics And Administrative Sciences
Notes on Exponential Distribution
...Show More Authors

المتغير العشوائي X  له توزيع أسي اذا كان له دالة احتمالية الكثافة بالشكل:

عندما  ، هذه هي الحالة الخاصة لتوزيع كاما.

غالباً جداً ولسبب معقول تأخذ . الحالة الخاصة لـ (1) التي نحصل عليها تسمى بالتوزيع الاسي لمعلمة واحدة.

اذا كانت  ، ، التوزيع في هذه الحالة يسمى التوزيع الاسي القياسي

اما بالنسب

... Show More
View Publication Preview PDF
Crossref
Publication Date
Tue Mar 01 2011
Journal Name
Journal Of Economics And Administrative Sciences
Notes on Weibull Distribution
...Show More Authors

Weibull Distribution is one of most important distribution and it is mainly used in reliability and in distribution of life time. The study handled two parameter and three-parameter Weibull Distribution in addition to five –parameter Bi-Weibull distribution. The latter being very new and was not mentioned before in many of the previous references. This distribution depends on both the two parameter and the three –parameter Weibull distributions by using the scale parameter (α) and the shape parameter (b) in the first and adding the location parameter (g)to the second and then joining them together to produce a distribution with five parameters.

... Show More
View Publication Preview PDF
Crossref
Publication Date
Wed Sep 01 2010
Journal Name
Journal Of Economics And Administrative Sciences
Finding Mixture Weibull Distribution
...Show More Authors

In this paper a new idea was introduced which is finding a new distribution from other distributions using mixing parameters; wi  where  0 < wi < 1 ­and . Therefore we can get many mixture distributions with a number of parameters. In this paper I introduced the idea of a mixture Weibull distribution which is produced from mixing two Weibull distributions; the first with two parameters, the scale parameter , and the shape parameter,  and the second also has the scale parameter , and the shape parameter,  in addition to the location parameter, . These two distributions were mixed using a new parameter which is the mixing parameter w which represents the proportion

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sat Sep 01 2012
Journal Name
Journal Of Economics And Administrative Sciences
Notes on Weibull Distribution
...Show More Authors

Weibull Distribution is one of most important distribution and it is mainly used in reliability and in distribution of life time. The study handled two parameter and three-parameter Weibull Distribution in addition to five –parameter Bi-Weibull distribution. The latter being very new and was not mentioned before in many of the previous references. This distribution depends on both the two parameter and the three –parameter Weibull distributions by using the scale parameter (α) and the shape parameter (b) in the first and adding the location parameter (g)to the second and then joining them together to produce a distribution with five parameters.

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sun Dec 29 2019
Journal Name
Iraqi Journal Of Science
Distribution of Polycyclic Aromatic Hydrocarbons in Water and Sediments in the Euphrates River, Iraq
...Show More Authors

The monitoring of lotic ecosystems is important for environmental health after war crisis. This study aimed to detect the fate of the sixteen polycyclic aromatic hydrocarbon compounds (PAHs) as priority pollutants in the water and sediment of Al-Hussainya River in Karbala Province. The results indicated that the concentrations in water samples ranged from 0.24–58.72 ηg.L-1 for each of the benzo(a) pyrene and benzo(g, h, i)perylene. The concentrations in sediment samples have been observed to be in a range of 0.36–119.06 μg.g-1 for naphthalene and benzo(g,h,i)perylene. Benzo(g,h,i)perylene recorded the highest concentrations in each of water and sediment samples as compared with the other compound

... Show More
View Publication Preview PDF
Scopus (4)
Crossref (3)
Scopus Crossref
Publication Date
Sat May 01 2021
Journal Name
Key Engineering Materials
The Effect of Temperature Width on Dielectric Constant of Vanadium Dioxide
...Show More Authors

A significant influence of temperature width found on the vanadium oxide properties, it plays a major role in highlighting the thermal limits of the three phases (metallic, semiconductor, and dielectric). Two values of the temperature width , and , had taken and studied their effect on both the dielectric constant and its two parts; refractive index, and extinction coefficient, and. It found that: as the temperature width is greater, the more the properties of the three phases for . In addition to increasing the thermal range for phases which can be reached to when , while it's at . Our results have achieved great compatibility with the published results globally. In addition to the effect of both ultraviolet, visible, and infrared

... Show More
View Publication
Scopus (4)
Crossref (5)
Scopus Crossref
Publication Date
Mon Sep 25 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Effect of Annealing Temperature on the Structural Characteristics of(Sb203) Compound.
...Show More Authors

The crystal structure and unit cell dimensions of the (S03) compound have  been determined by employing the principles of crystallography.

The X-Ray diffraction spectra of (Sb203) which recorded as a function  of   different  annealing  temperatures  (100,150,200  and

 

250)±5c and for durations (0.5  hr,

0

 

1hr, l.Shr and 2hr), showed a

 

noticeable improvement, a decreasing in the unit cell dimensions and

an increasing in the number of diffraction spectra.

Indexing of diffraction spectra and refinement of  unit cell

dimensions showed that the compound (Sb203)  which is a

... Show More
View Publication Preview PDF
Publication Date
Sat Aug 12 2017
Journal Name
Journal Of Engineering
Influence of Temperature Upon Permanent Deformation Parameters of Asphalt Concrete Mixes
...Show More Authors

        The performance of asphalt concrete pavement has affected by many factors, the temperature is the most important environmental one which has a large effect on the structural behavior of flexible pavement materials. The main cause of premature failure of pavement is the rutting, Due to the viscoelastic nature of the asphalt cement, rutting is more pronounced in hot climate areas because the viscosity of the asphalt binder which is
inversely related to rutting is significantly reduced with the increase in temperature resulting in a more rut susceptible paving mixtures. The objective of this study is to determine the effect of temperatures variations on the permanent deformation parameters (perm

... Show More
View Publication Preview PDF