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
Mon Jun 22 2020
Journal Name
Baghdad Science Journal
Effects of Anthracene Doping Ratio and UV Irradiation Time on Photo-Fries Rearrangement of Polycarbonate
...Show More Authors

Thin films of pure polycarbonate (PC) with anthracene doping PC films for different doping ratios (10, 20, 30, 40, 50 and 60 ml) were prepared by using a casting method. The influence of anthracene doping ratio on photo-fries rearrangement of polycarbonate was systematic investigated. Furthermore, pure PC and anthracene doping PC films were irradiated via UV light at a wavelength (254 nm) for different periods (5, 240, 288, and 360 hrs). The photo-fries rearrangement occurring in pure PC and anthracene doping PC films were monitored using UV and FTIR spectroscopies. The photo-fries rearrangement leads to scission the carbonate linkage and formation phenylsalicylate and dihydroxybenzophenes. The result of the UV spectrum confirms disappea

... Show More
View Publication Preview PDF
Scopus (3)
Crossref (1)
Scopus Clarivate Crossref
Publication Date
Thu Apr 30 2020
Journal Name
Journal Of Economics And Administrative Sciences
Estimate the Partial Linear Model Using Wavelet and Kernel Smoothers
...Show More Authors

This article aims to estimate the partially linear model by using two methods, which are the Wavelet and Kernel Smoothers. Simulation experiments are used to study the small sample behavior depending on different functions, sample sizes, and variances. Results explained that the wavelet smoother is the best depending on the mean average squares error criterion for all cases that used.

 

 

View Publication Preview PDF
Crossref
Publication Date
Thu Feb 01 2024
Journal Name
Baghdad Science Journal
Building a Sustainable GARCH Model to Forecast Rubber Price: Modified Huber Weighting Function Approach
...Show More Authors

The unstable and uncertain nature of natural rubber prices makes them highly volatile and prone to outliers, which can have a significant impact on both modeling and forecasting. To tackle this issue, the author recommends a hybrid model that combines the autoregressive (AR) and Generalized Autoregressive Conditional Heteroscedasticity (GARCH) models. The model utilizes the Huber weighting function to ensure the forecast value of rubber prices remains sustainable even in the presence of outliers. The study aims to develop a sustainable model and forecast daily prices for a 12-day period by analyzing 2683 daily price data from Standard Malaysian Rubber Grade 20 (SMR 20) in Malaysia. The analysis incorporates two dispersion measurements (I

... Show More
View Publication Preview PDF
Crossref (1)
Scopus Crossref
Publication Date
Tue Nov 01 2016
Journal Name
Journal Of Economics And Administrative Sciences
Evaluation of projects during the trial operation period in accordance with the cost, quality and time - applied research in the Directorate-General for the distribution
...Show More Authors

Research includes evaluation of projects implemented and which entered into trial operation period in accordance with the evaluation criteria and of (cost, quality and time) to determine the size deviations gap for the sample of projects during the years of assessment (2011-2012-2013-2014) of each of the three evaluation criteria, and then followed by a calculation the size of the overall gap to the problem based on the research problem to determine deviations from the specific implementation of each project by answering several questions to answer turns out the reasons for these deviations occur.

The importance of research Focus on the evaluation of received projects from contractors executing the projec

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sun May 02 2021
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
The effect of applying lean construction tools to improving the results of the earned value management model: Applied research in Al-Rasheed General Company for Construction Contracting
...Show More Authors

Contracting companies play a prominent role today in economic activity, due to their contribution to the implementation of major construction projects which together constitute the infrastructure of society. Most construction projects also suffer from exceeding the time and cost specified and planned for the completion of the project, and this comes for several reasons, including the work environment, country conditions, The method of managing project costs and the techniques used in its implementation Accordingly, the concepts of lean construction came, which help in addressing the causes of waste, both in time and cost, in addition to the fact that project management needs techniques that are useful in controlling the control and manag

... Show More
View Publication Preview PDF
Publication Date
Thu Dec 14 2023
Journal Name
Malaysian Journal Of Mathematical Sciences
The Effect of Alternative Resource and Refuge on the Dynamical Behavior of Food Chain Model
...Show More Authors

This article examines and proposes a dietary chain model with a prey shelter and alternative food sources. It is anticipated that mid-predators' availability is positively correlated with the number of refuges. The solution's existence and exclusivity are examined. It is established that the solution is bounded. It is explored whether all potential equilibrium points exist and are locally stable. The Lyapunov approach is used to investigate the equilibrium points' worldwide stability. Utilizing a Sotomayor theorem application, local bifurcation is studied. Numerical simulation is used to better comprehend the dynamics of the model and define the control set of parameters.

View Publication
Scopus (10)
Crossref (4)
Scopus Clarivate Crossref
Publication Date
Tue Jun 01 2021
Journal Name
Political Sciences Journal
The European Union and the Extremist Right Phenomenon: Brexit as a Model
...Show More Authors

The European Unit has never been affected by a serious phenomena as the phenomena of the advancing of the far right parties. Though these parties vary in their impact in their original countries, they agree on one important issue which is the deconstruction of the European unit and limiting its supernational powers. These increasing popular parties aim at more national independence in decision making away from the decisions taken by Brussels. Moreover, they criticize the financial and administrative corruption accompanied many of the rescuing procedures directed for example towards countries like Greece and Spain during the international economic crisis. This failure nourishes many of the negative feelings against the European unit which

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sat Aug 24 2024
Journal Name
Mathematics
Identification of Time-Wise Thermal Diffusivity, Advection Velocity on the Free-Boundary Inverse Coefficient Problem
...Show More Authors

This paper is concerned with finding solutions to free-boundary inverse coefficient problems. Mathematically, we handle a one-dimensional non-homogeneous heat equation subject to initial and boundary conditions as well as non-localized integral observations of zeroth and first-order heat momentum. The direct problem is solved for the temperature distribution and the non-localized integral measurements using the Crank–Nicolson finite difference method. The inverse problem is solved by simultaneously finding the temperature distribution, the time-dependent free-boundary function indicating the location of the moving interface, and the time-wise thermal diffusivity or advection velocities. We reformulate the inverse problem as a non-

... Show More
View Publication Preview PDF
Scopus (1)
Crossref (1)
Scopus Clarivate Crossref
Publication Date
Fri Nov 01 2019
Journal Name
International Journal On Interactive Design And Manufacturing (ijidem)
A real-time automated sorting of robotic vision system based on the interactive design approach
...Show More Authors

View Publication
Scopus (39)
Crossref (31)
Scopus Clarivate Crossref
Publication Date
Sun Nov 01 2009
Journal Name
Tencon 2009 - 2009 Ieee Region 10 Conference
Optimizing the MPLS support for real time IPv6-Flows using MPLS-PHS approach
...Show More Authors

View Publication
Scopus (4)
Scopus Crossref