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jih-1429
Using The Ultrasonic Waves For Studying Thermal And Elastic Properties as a Function of Porosity in Sintered ceramic
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Ultrasonic pulse echo measurements on porous alumina as ceramic

material with porosities ranging from (20-40)% showed effect of volume

fraction of porosity on both thermal and elastic properties. A quadratic relationships, by using a least squares method, is deduced for the dependence of the shear velocity, longitudinal velocity, shear modulus, Young's modulus,  bulk  modulus, Poisson 's ratio, Debye temperature, specific heat, and thermal conductivity on the total  porosity. By these relationships,  the  thermal  and  elastic  properties  results  of  pore-free alumina  were  calculated.  The  elastic  properties  results  of  ceramic decrease substantially  with  increasing porosity,  except  Poisson 's  ratio which is the constant. Debye temperature and thermal conductivity decrease too substantially with increase of porosity, while specific heat increases.

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Publication Date
Sat Dec 30 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
IR and Uv-Visible Study of the Thermal Stabilization for pvc Stabilized with ( Ho,Tb and Dy ) Stearate and Synergistic Mixtures
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Three  types of  metal  carboxylates  (Ho,Tb  and  Dy) stearates were LLSed  as thennal stabi lizers for PVC. Infrared spectra (1500-1900

 

)

 

cm.1

 

were   studied   for  PVC   films   stabilized   with   these   metal

 

carboxylatcs.  Two types of oxygen  were round -containing  products that were formed during  the thermal degradation  .On the other hand , the  presence &nb

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Publication Date
Tue Jun 08 2021
Journal Name
مجلة العلوم و التكنولوجية للنشاطات البدنية و الرياضية
The effectiveness of using (7E’s) learning cycle in learning a movement chain on the uneven bars in the artistic gymnastics for women
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Abstract The Object of the study aims to identify the effectiveness of using the 7E’s learning cycle to learn movement chains on uneven bars, for this purpose, we used the method SPSS. On a sample composed (20) students on collage of physical education at the university of Baghdad Chosen as two groups experimental and control group (10) student for each group, and for data collection, we used SPSS After collecting the results and having treated them statistically, we conclude the use 7E’s learning cycle has achieved remarkable positive progress, but it has diverged between to methods, On this basis, the study recommended the necessity of applying 7E’s learning cycle strategy in learning the movement chain on uneven bar

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Publication Date
Tue Oct 20 2020
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Estimating of Survival Function under Type One Censoring Sample for Mixture Distribution
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In this article, it is interesting to estimate and derive the three parameters which contain two scales parameters and one shape parameter of a new mixture distribution for the singly type one censored data which is the branch of right censored sample. Then to define some special mathematical and statistical properties for this new mixture distribution which is considered one of the continuous distributions characterized by its flexibility. Next,  using maximum likelihood estimator method for singly type one censored data based on the Newton-Raphson matrix procedure to find and estimate values of these three parameter by utilizing the real data taken from the National Center for Research and Treatment of Hematology/University of Mus

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Publication Date
Sun Jan 20 2019
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Bayesian Estimation for Two Parameters of Gamma Distribution Under Precautionary Loss Function
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In the current study, the researchers have been obtained Bayes estimators for the shape and scale parameters of Gamma distribution under the precautionary loss function, assuming the priors, represented by Gamma and Exponential priors for the shape and scale parameters respectively. Moment, Maximum likelihood estimators and Lindley’s approximation have been used effectively in Bayesian estimation.

Based on Monte Carlo simulation method, those estimators are compared depending on the mean squared errors (MSE’s). The results show that, the performance of Bayes estimator under precautionary loss function with Gamma and Exponential priors is better than other estimates in all cases.

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Publication Date
Fri Apr 01 2016
Journal Name
Journal Of Economics And Administrative Sciences
Comparing Bayes Estimators With others , for scale parameter and Reliability function of two parameters Frechet distribution
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Publication Date
Tue Jun 14 2022
Journal Name
Chemical Papers
Nile red based dye D–π–A as a promising material for solar cell applications
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A recently reported Nile red (NR) dye conjugated with benzothiadiazole species paves the way for the development of novel organic-based sensitizers used in solar cells whose structures are susceptible to modifications. Thus, six novel NR structures were derived from two previously developed structures in laboratories. In this study, density functional theory (DFT) calculations and time-dependent DFT (TD-DFT) were used to determine the optoelectronic properties of the NR-derived moieties such as absorption spectra. Various linkers were investigated in an attempt to understand the impact of π-linkers on the optoelectronic properties. According to the findings, the presence of furan species led to the planarity of the molecule and a reduction

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Publication Date
Fri Jan 07 2022
Journal Name
Iraqi Journal Of Laser
Influence of Fractional CO2 Laser Irradiation on Temperature Elevation and Bonding Strength of Resin Cement to the Zirconia Ceramic
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Abstract: Objectives: To investigate the effect of temperature elevation on the bonding strength of resin cement to the zirconia ceramic using fractional CO2 laser. Background: Fractional CO2 laser is an effective surface treatment of zirconia ceramic, as it increases the bonding strength of zirconia to resin cement. Methods: Thirty sintered zirconia discs (10 mm diameter, 2 mm thickness) were prepared and divided to three groups (N=10) and five diffident pulse durations were used in each group (0.1, 0.5, 1, 5 and 10 ms). Group A was treated with 10 W power setting, group B with 20 W and group C with 30 W. During laser irradiation, temperature elevation measurement was recorded for each specimen. Luting cement was bonded to the treated z

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Publication Date
Thu May 14 2020
Journal Name
Journal Of Planner And Development
Visual Pollution and its Impact on the Aesthetics: The Town of Eizariya as a Model
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This study seeks to shed light on the aspects of visual pollution and its impact on the aesthetics of the town of Al-Eizariya known to suffer from the phenomenon. In order to identify the real causes of the problem which develops in various forms and patterns, threatening not only the aesthetic appearance of the towns, but also causes the emergence of new problems and phenomena that will have negative repercussions on the population. The researcher uses the analytical descriptive method to analyze the phenomenon of visual pollution in terms of reality, development, manifestations and spread and uses photos which document the visual pollution and its impact on the aesthetics of the known. The study concluded the existence of a strong rela

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Publication Date
Sun Dec 02 2018
Journal Name
Journal Of The College Of Education For Women
Poverty and its Relations to Some Social Variables (Children in the Primary Stage as a Model)
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The phenomenon of poverty is one of the most important phenomena facing the world at large. Despite the tremendous technological progress witnessed by mankind and despite the unprecedented high levels of world economic production, poverty remains the greatest challenge facing the world. Statistics and studies have shown that poverty is caused by several problems: (health, social, economic, educational, etc.) These problems are obstacles to the ability to obtain employment opportunities, which leads in the beginning to the growth phenomenon of unemployment, and ultimately to the growth of poverty.

The results of a range of research in the field of psychology have confirmed that children from poor homes suffer from a high level of

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Publication Date
Sun Jun 22 2025
Journal Name
Journal Of Kufa For Chemical Sciences
Evaluation of Oxidative Stress and Liver Function Parameters in the Sera Samples of Kufa Cement Factory Workers
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AbstractThe objective of the present study was measured of several oxidative stresses and liver function parameters in workers occupationally exposed to cement dust in Kufa Cement Factory, in order to test the hypothesis that cement dust exposure may perturb these parameters. Assessment of oxidative stress and liver function parameters were performed in 63 workers occupationally, in different departments of Kufa Cement Factory, exposed to cement dust (range of the exposure time was 5-38 years) and 36 matched unexposed controls. The study results illustrated an increasing in the oxidative stress parameters, moreover; liver function parameters showed abnormal results in the exposed workers compared to the unexposed. An increase in theses para

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