Preferred Language
Articles
/
yxd7opEBVTCNdQwCG5ac
THE EVOLUTION OF PLANETARY NEBULAE(PN) AND FADING TIME ACCORDING TO SYNTHETIC MODEL
...Show More Authors

Abstract Planetary nebulae (PN) represents the short phase in the life of stars with masses (0.89-7) M☉. Several physical processes taking place during the red giant phase of low and intermediates-mass stars. These processes include :1) The regular (early ) wind and the envelope ejection, 2) The thermal pulses during Asymptotic Giant Branch (AGB ) phase. In this paper it is briefly discussed how such processes affect the mass range of Planetary Nebulae(PN) nuclei(core) and their evolution, and the PN life time, and fading time for the masses which adopted. The Synthetic model is adopted. The envelope mass of star (MeN ) and transition time (ttr) calculated respectively for the parameter (MeR =1.5,2, 3×10-3 M☉). Another time scale is of capital importance for the understanding of PN and their nuclei, it is the fading time ( tf). The results indicated that for each observed nebulae( ttr < tPN) also the fading time is sensitive to mass core(MH) of star, the mass with 1.2 M☉ takes only (25 yr ) to fading, while the mass with (0.66 M☉) takes about ( 4715 yr) years to fading. The calculations showed that (ttr) increases with the increasing of final mass( Mf). The initial nebulae radius will also increase with (Mf) thus will correlate with the location of nucleus on the HR diagram.

Preview PDF
Quick Preview PDF
Publication Date
Thu Jun 30 2022
Journal Name
Journal Of Economics And Administrative Sciences
Examining the Asymmetric Impacts of Interest and Exchange Rate on Investment in Egypt for the Period 1976-2020: Applying NARDL Model
...Show More Authors

Most of the studies conducted in the past decades focused on the effect of interest rates and exchange rates on domestic investment under the assumption that the independent variables have the same effect on the dependent variable, but there were limited studies that investigated the unequal effects of changes in interest rates and exchange rates, both positive and negative, on domestic investment.  This study used a nonlinear autoregressive distributed lag (NARDL) model to assess the unequal effects of the real interest rate and real exchange rate variables on domestic investment in Egypt for the period 1976 - 2020.  The results revealed that positive and negative shocks for both exchange rates have unequal effects on

... Show More
View Publication Preview PDF
Crossref
Publication Date
Wed Feb 01 2017
Journal Name
Journal Of Economics And Administrative Sciences
A comparison between the logistic regression model and Linear Discriminant analysis using Principal Component unemployment data for the province of Baghdad
...Show More Authors

     The objective of the study is to demonstrate the predictive ability is better between the logistic regression model and Linear Discriminant function using the original data first and then the Home vehicles to reduce the dimensions of the variables for data and socio-economic survey of the family to the province of Baghdad in 2012 and included a sample of 615 observation with 13 variable, 12 of them is an explanatory variable and the depended variable is number of workers and the unemployed.

     Was conducted to compare the two methods above and it became clear by comparing the  logistic regression model best of a Linear Discriminant  function written

... Show More
View Publication Preview PDF
Crossref
Publication Date
Wed Jun 01 2011
Journal Name
Journal Of Economics And Administrative Sciences
Methods of using the periodic chart in the case of the missing values of the stable AR model (2)
...Show More Authors

In this study, we investigate the behavior of the estimated spectral density function of stationary time series in the case of missing values, which are generated by the second order Autoregressive (AR (2)) model, when the error term for the AR(2) model has many of continuous distributions. The Classical and Lomb periodograms used to study the behavior of the estimated spectral density function by using  the simulation.

 

View Publication Preview PDF
Crossref
Publication Date
Fri Apr 26 2024
Journal Name
Mathematical Modelling Of Engineering Problems
Solving Tri-criteria: Total Completion Time, Total Earliness, and Maximum Tardiness Using Exact and Heuristic Methods on Single-Machine Scheduling Problems
...Show More Authors

View Publication
Scopus (2)
Crossref (1)
Scopus Crossref
Publication Date
Sun Feb 03 2019
Journal Name
Journal Of The College Of Education For Women
Anti-Social behavior and its relationship to the need to love at Baghdad University students
...Show More Authors

1. Anti-social behavior Baghdad University students.
2. Know the differences in anti's social behavior according to gender, specialization.
3. Know-the need for love at Bagdad University students.
4. Know the relationship between anti-social behavior and the need to love.
The research sample consisted of (100) students, the researcher numbers tools to measure anti behavior and the need to love.
The results showed that college students have an anti-social behavior is weak and they need to love and there is no correlation between them Function relationship. Researcher has shown a number of recommendations and proposals.

View Publication Preview PDF
Publication Date
Tue Aug 08 2023
Journal Name
مجلة حمورابي للدراسات
adolescents exposure to the specialized satellite channel cartoon network and its relationship to their level of technological culture
...Show More Authors

Publication Date
Mon Nov 01 2021
Journal Name
Iop Conference Series: Earth And Environmental Science
Biological Effect of Different Concentrations of Bacillus Thurngensis Isolated From The Soils of Sawa Lake, Al Muthanna Governorate on The of Hypera postica at Different Time Periods
...Show More Authors
Abstract<p>This study conduct in Al-Muthanna governorate to assess five concentrations of <italic>Bacillus</italic> thurngensisagonist <italic>Hyperapostica</italic>. The results showed the presence of <italic>Bacillus thurngensisin</italic> all the studied sites of Lake Sawa in Muthanna Governorate, and the rates of its presence were close to the same sites, and the rate of its presence in those sites was 35%, and its highest rate was recorded in the north and east of the lake, as it reached 40% and the lowest amounted to 30% in the two sites south and west site. The results of the study showed that five concentrations were taken from bacterial isolates of <it></it></p> ... Show More
View Publication
Scopus Crossref
Publication Date
Sun Sep 02 2012
Journal Name
Baghdad Science Journal
Evaluation of the Compton (Incoherent) and Rayleigh (Coherent) Differential Cross Sections of Scattering for Rhodium 103Rh45 and Tantalum181Ta73 by Employing CSC model
...Show More Authors

The differential cross section for the Rhodium and Tantalum has been calculated by using the Cross Section Calculations (CSC) in range of energy(1keV-1MeV) . This calculations based on the programming of the Klein-Nashina and Rayleigh Equations. Atomic form factors as well as the coherent functions in Fortran90 language Machine proved very fast an accurate results and the possibility of application of such model to obtain the total coefficient for any elements or compounds.

View Publication Preview PDF
Crossref (2)
Crossref
Publication Date
Fri Feb 15 2019
Journal Name
Route Educational & Social Science Journal
The effect of the 4-H model on self-regulated learning and life skills for female chemistry students in the second intermediate year
...Show More Authors

Publication Date
Wed Aug 01 2018
Journal Name
Journal Of Economics And Administrative Sciences
Analysis of the Current Financial Crisis : Causes and Solutions (Iraqi crisis a model , based on the public budget for the fiscal year 2016)
...Show More Authors

The research aims to analysis of the current financial crisis in Iraq through knowing its causes and then propose some solutions that help in remedy the crisis and that on the level of expenditures and revenues, and has been relying on the Federal general budget law of the Republic of Iraq for the fiscal year 2016 to obtain the necessary data in respect of the current expenditures and revenues which necessary to achieve the objective of the research , and through the research results has been reached to a set of conclusions which the most important of them that causes of the current financial crisis in Iraq , mainly belonging to increased expenditures and especially the current ones and the lack of revenues , especially non-oil o

... Show More
View Publication Preview PDF
Crossref