The term ‘photometry’ refers to the accurate determination of the apparent brightness of an astronomical object. Until roughly 1980, nearly all astronomical photometry was done by means of analog measurements of photographic plates, or by analog or digital (photon-counting) techniques with photomultipliers. These photometers produced brightness readings which were typically displayed on dials, plotted on strip charts or printed on strips of paper, and it was often quite practical to analyse these raw data with pencil, paper and a slide rule or table of logarithms. However, during the late 1970s electronic area detectors for astronomy became more advanced: first, for a brief period, television-type cameras were employed, but these were soon supplanted by CHARGECOUPLED DEVICES (CCDs), which remain overwhelmingly the detector of choice to the present day(Murdin 2001). The spiral galaxy NGC 3351 is chosen to study its photometric properties by using surface photometric techniques with griz-filters which is the main goal of this study. Observations are obtained from the seventh Sloan Digital Sky Survey (SDSS) Data Release (DR7)(Abazajian et al., 2009). All the images are corrected for bias and flat field by SDSS pipeline. We have analyzed the overall structure of the galaxy (a bulge, a disk, a bar), together with isophotal contour maps, luminosity profiles and performed a bulge/disk decomposition of the galaxy images, although we have estimated the disk position angle, ellipticity and inclination of the galaxy, it is favorable for investigating the brightness and color distributions over the disk of the galaxy. It is clear that the galaxy has a bright ring dominates the appearance of the circumnuclear, and a faint disk does not take on a spiral form , and from the position angle, ellipticity and B4 profiles of galaxy isophotes the values of the P.A. and ellipticity are fluctuated because of the bar and ring. The luminosity profile shows that the outer disk of this galaxy is of type II Freeman. Finally, the color indices of the NGC 3351 galaxy are characteristic of a normal spiral galaxy with some irregularity.
The Internet is providing vital communications between millions of individuals. It is also more and more utilized as one of the commerce tools; thus, security is of high importance for securing communications and protecting vital information. Cryptography algorithms are essential in the field of security. Brute force attacks are the major Data Encryption Standard attacks. This is the main reason that warranted the need to use the improved structure of the Data Encryption Standard algorithm. This paper proposes a new, improved structure for Data Encryption Standard to make it secure and immune to attacks. The improved structure of Data Encryption Standard was accomplished using standard Data Encryption Standard with a new way of two key gene
... Show More
(4)
(1)
Each sport has its own energy requirements that differ from the energy requirements of other sports, and a different method is used in each of them, so the trainer must first rely on the principle of privacy in training first, that is, privacy according to the working energy system, that is, he defines the controlling energy system In that event, and how the muscles use the available energy to perform according to the energy production systems. As we find the serving skill is the first volleyball skill with which the team starts the match in order to be able to gain points directly, through knowledge it turns out that there is a weakness in the skill performance, especially the skill of serving and being The key to victory for volle
... Show More
(1)
The status of the semi total stoppage and non-use and waste of economic made studying and analyzing Dutch disease of high importance because it is a major cause in aggravation of this status which happened to the Iraqi economy in almost complete way and the relative big importance that oil source has and its domination on the largest percentage in the gross domestic product and exports that Iraqi economy is relying largely in funding the national budget made the concentration of the study on this subject an important and necessary within the important economic events that Iraqi economy witnessed after 2003 till 2016 to give a clear and an overall picture of the reality of the unilateral Iraqi economy under the status of semi tota
... Show More
This investigation was conducted to recognize the structure for (RHETI version 2.5 1999) by using exploratory and confirmatory factor analysis. Sample of (620) student of Al-Mustansrya University were administered the (RHETI).
The data of their responses was analyzed by using (PAF) and oblique rotating .
The findings explored (9) factors as one factor for each type and (184) items were loaded by the factors: (60) item for feeling center, (61) items for instinctive center and (63) items for thinking center.
Results of confirmatory factorial analysis supported a model designed by the researcher depended upon a theoretical views of Riso and Hudson
... Show MoreAn investigation of the quadrupole deformation of Kr, Sr, Zr, and Mo isotopes has been conducted using the HFB method and SLy4 Skyrme parameterization. The primary role of occupancy of single particle state 2d5/2 in the existence of the weakly bound structure around N=50 is probed. Shell gaps are performed using a few other calculations for the doubly magic number 100Sn using different Skyrme parameterizations. We explore the interplays among neutron pairing strength and neutron density profile in two dimensions, along with the deformations of 100Sn.
(1)
(1)
(2)
(2)
Density Functional Theory at the generalized-gradient approximation level coupled with large unit cell method is used to simulate the electronic structure of (II-VI) zinc-blende cadmium sulfide nanocrystals that have dimensions 2-2.5 nm. The calculated properties include lattice constant, conduction and valence bands width, energy of the highest occupied orbital, energy of the lowest unoccupied orbital, energy gap, density of states etc. Results show that lattice constant and energy gap converge to definite values. However, highest occupied orbital, lowest unoccupied orbital fluctuates indefinitely depending on the shape of the nanocrystal.
يهدف البحث إلى التعرف على The research aims to identify the effect ofاثر التركيب العمري للسكان على الناتج المحلي الإجمالي في العراق وتحديد الفئات العمرية من أطفال ومنتجين أي من هم في سن العمل والمسنين لأهمية ذلك لإغراض التخطيط الاقتصادي.إنeffectofeee age structure of the population on GDP in Iraq and determine the age groups of children and any of the producers wham are of working age and the elderly of the importance for the purposes of economic planning. نسبة الفئة العمرية Proportion of the age group (00- -4 4سنوات اقتربت من
... Show More