Radio observations from astronomical sources like supernovae became one the most important sources of information about the physical properties of those objects. However, such radio observations are affected by various types of noise such as those from sky, background, receiver, and the system itself. Therefore, it is essential to eliminate or reduce these undesired noise from the signals in order to ensure accurate measurements and analysis of radio observations. One of the most commonly used methods for reducing the noise is to use a noise calibrator. In this study, the 3-m Baghdad University Radio Telescope (BURT) has been used to observe crab nebula with and without using a calibration unit in order to investigate its impact on the signal. Radio observations of crab nebula have been carried out for different periods in 2022. Several parameters of the telescope have been calculated and analyzed using statistical measurements with and without using the noise calibration unit. Those parameters are receiver gain, system temperature, antenna temperature, and degree per flux unit. The results of this research revealed that the fluctuation sensitivity of BURT improved by about an order of magnitude, when the noise calibration unit is used. The root mean square error and the radiometer equation of the antenna temperature decreased to less than 33% and 10%, respectively in comparison to their initial values. In conclusion, the noise calibration unit plays a crucial role to improve the sensitivity of a radio telescope drastically.
The aim of this paper, study the effect of carbon nanotubes on the electrical properties of polyvinylchloride. Samples of polyvinylchloride carbon nanotubes composite prepared by using hot press technique. The weight percentages of carbon nanotubes are 0,5,10 and 20wt.%. Results showed that the D.C electrical conductivity increases with increasing of the weight percentages of carbon nanotubes. Also, the D.C electrical conductivity changed with increase temperature for different concentrations of carbon nanotubes. The activation energy of D.C electrical conductivity is decreased with increasing of carbon nanotubes concentration.
Abstract
Tourism is one of the essential economic fields of many countries, both developed and developing. The social plays a greater role in the continuous awareness of a tourist culture based on the need to attract tourists continuously. the tourism heritage and state-owned tourism are the main factors in attracting more tourists. The interest in this strategic sector makes the country the first and most active framework in the development of appropriate mechanisms for investment in this sector, all within the framework of sustainable development of society through the rational use of resources obtained by various bodies in the implementation of seve
... Show MoreThe study aims at showing the active role of the internal auditors through explaining what they should be obliged to in writing the reports and financial and non financial statements according to the international standards of accounting to be transparent and integral. It also aims at giving the independence that the auditors should enjoy through connecting them to an Auditing Commissions to submit additional services in addition to assessing the instrument of control to evaluate risks, give consultations and the services related to the governance and independence of Supervising Council.
... Show MoreLinguistic studies present a distinguished place among modern human studies, as we find this clear in the scientific research institutions of the developed nations, it is the main pillar in the strengthening of links and consolidation pillars between individuals and groups. It is a language and between people's thoughts, feelings and actions, and has been able to show that language is not only a tool of expression but is closely linked to the intellectual, emotional and social life of these people individuals and groups.
The derivation is a major step in Arabic in classifying formulas into weights with special morphological values; these are of great importance in sentences and structures that are the domain of the searc
This research aims to study a range of yet and future variables that can affect human resources in Iraq and public organizations that influence the size of each, and the extent of its contribution to the development of human resources through the National Investment Commission of Baghdad. The identified research problem in a set of questions was the most important, what are the variables that help in the development of human resources to the Investment Commission of Baghdad theme of the search, in order to achieve the goal of research and answer questions about the problem, applied research on both the research community's (55) individual executives and employees.
Researcher has identified a r
... Show MoreThe compound chalcon originally is extracted form some plant and herbs, the studies of the antiviral activity of this compound were done in two cell line cultures the L2OB and RD, the compound relatively non toxic to both cell lines of the concentration of 32?g/ml or less ,the compound have significantly anti poliovirus activity in both L2OB cell line and RD cell line, we find that the concentration of 0.03 ?g/ml or more inhibit the 100TCDID50 of the poliovirus .The therapeutic index(TI)used in this study to evaluate the drug activity ,( TI is the ratio of dose of drug which is just toxic to the cells to the does which is just inhibit the viral multiplication, if this index more than one the margin of safety of drug is according great ) .In
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This research was carried out in quail in the laboratory of histopathology diseases during four months. The objectives of this study was to detecting the effects of the addition of the alcohol extract of ginger to ovary tissue of quail. The two groups of birds were in almost similar weights and were placed in cages. Each group consisted of 8 quails. The first group (control group) fed on regular feeding without adding alcoholic extract of ginger. The second group (treated group) fed on the same normal food after adding the alcohol extract of ginger at a concentration of 300 mg / kg. The results indicated that ginger have positive effects on folliculogenesis.