One of the most powerful tools for any stellar dynamics is the N-body simulation. In an N-body simulation the motion of N particles is followed under their mutual gravitational attraction. In this paper the gravitational N-body simulation is described to investigate Newtonian and non- Newtonian (modified Newtonian dynamics) interaction between the stars of spiral galaxies. It is shown that standard Newtonian interaction requires dark matter to produce the flat rotational curves of the systems under consideration, while modified Newtonian dynamics (MOND) theorem provides a flat rotational curve and gives a good agreement with the observed rotation curve; MOND was tested as an alternative to the dark matter hypothesis. So that MOND hypothesis has generated better rotation curves than Newtonian theorem. |
The success of any institution must be based on means to protect its resources and assets from the waste, loss, misuse and the availability of accurate and reliable data by accounting reports to increase its operational efficiency, namely, that the internal control system is considered as a safety valve for top management in any economic unit. The problem is represented by the need for an efficient system, so to ensure its success, there must exist external parties which monitor and evaluate the performance because of its importance by following clear criteria. So, the research problem came to address performance evaluation indicators which are set by the Federal Board of Supreme Audit (FBSA) and identify the extent of its contribution t
... Show MoreIntroduction and Aim: Klebsiella pneumoniae is a Gram-negative bacterium responsible for a wide range of infections, including respiratory tract infections (RTIs). This research was aimed to study the antibacterial and anti-biofilm effect of AgNPs produced by Gram positive and negative bacteria on RTIs associated with K. pneumoniae. Materials and Methods: The biofilm formation of K. pneumoniae was determined by tube method qualitatively from select bacterial species characterized by UV-Visible spectroscopy. The antibacterial susceptibility of the bacteria AgNPs was tested for their antibacterial and antibiofilm activity on a clinical isolate of K. pneumoniae. Results: K. pneumoniae isolated from RTIs were strong biofilm prod
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The objective of this research is to analyze the relationship between the strategic planning for human resources and career path, and I have tested Search the Ministry of Health and some health centers headquarters in the Karkh district, that is applied in sample Consist of (45) Deputy Director, Head of Depts, Departmental Manager, and health center Manager.
Find interested in studying the two subjects are important and vital, at the level of organizations at the present time, namely the strategic planning of human resources and career path. To achieve the objectives of the research was designed Qusestionnair (31) items to collect Primary data. and collected t
... Show More"The aim of the research is to identify the availability of the dimensions of the research variables represented by organizational symmetry and the quality of work-life at the University of Information and Communications Technology, which is one of the formations of the Ministry of Higher Education and Scientific Research in Baghdad, in addition to knowing the relationship and influence between them. The research relied on the descriptive analytical approach based on peer description. The research was analyzed and the research sample consisted of (148) individuals, the sample was chosen using the comprehensive inventory method, data was obtained by relying on the questionnaire which was prepared from ready-made m
... Show MoreCement kiln dust (CKD) is a waste of cement manufacture. The disposal dust becomes an environmental threat. In order to overcome this problem, researchers are carried out to find out the economical and the efficient means of utilizing it in various applications .One of these applications is adding it as partial replacement of cement. The aim of present work is investigating the effect of CKDs fineness on the consistency and setting time of cement, when utilized as a partial replacement. the CKD was grind by jet mill and classify into 7 groups according fineness (3000 , 6000 , 7000 , 8000 , 9000 , 10000 , 11000) cm2/gm then prepared blends with (5 ,10 , 15 , 20 , 25 , 30 , 35 and 40) % replacement by CKD for each fineness ,and compare bet
... Show MoreBackground: Polymethyl methacrylate (PMMA) is the most commonly used material in denture fabrication. The material is far from ideal in fulfilling the mechanical requirement. The purpose of this study was to evaluate the effect of addition of 3% wt of treated (silanized) Titanium oxide Nano filler on some physical and mechanical properties of heat cured acrylic denture base material. Materials and methods: 100 specimens were constructed, 50 specimens were prepared from heat cure PMMA without additives (control) and 50 specimens were prepared from heat cure PMMA with the addition of TiO2 Nano fillers. Each group was divided into 5 sub groups according to the test performed which was mixed by probe ultra-sonication machine. Results: A highly
... Show MoreThe solar energy is the major source of power for the future and an important source of renewable energy in Iraq and the world. Suitable climate conditions for solar energy are available in Iraq, especially the high temperature in the summer season which extends for more than six months in the year. Hence, the global solar radiation is abundant with high intensity, which is very essential in applicable models for researchers and solar applications. Therefore, nine first-order regression empirical equations of Angstrom-type correlations were used to estimate the more appropriate global solar radiation model for Baghdad city. Two equations were developed empirically in this work, using the most available and easy to get meteorological data
... Show MoreThe cytotoxic effect of different concentrations of Crude extracts of Bidens tripartita , Panex ginseng , Ceylon cinnamon and Citrullus colocynthis on mice mammary adenocarcinoma cell line were studied . The concentration used were 125 , 250, 500, 1000 Microgram/militer . The exracts were prepared by using hot water method . The preliminary chemical tests revealed acidic pH of all extracts. The time of exposure used were 24, 48 and 72 hrs.The results showed a clear toxic effect of all extracts depending on the time of exposure and the dose . The Ceylon cinnamon had the highest effect on adenocarcinoma 87.33% , followed by Bidens tripartita 86.79%, Citrullus colocynthis 74.39% and the lowes
... Show MoreBackground: Imprelon® Biostar foils are new alternative tray material that has become increasingly popular because oftheir several advantages. Also, (Duran®) is another type of Biostar foils which is used in splint therapy. This study assessed some mechanical properties of these two types Biostar sheets in comparison with some types of acrylic resins used for construction of trays and splints. Materials and Methods: A total of 150 specimens were prepared, 30 specimens for each test, 10 for each group material in order to assess some mechanical properties of the Imprelon® Biostar foil (dimension stability, surface roughness and shear bond strength of Imprelon® materialto zinc oxide impression material) and compare them to that of the oth
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