Based on the streamer growth model, the streamer discharge propagation was simulated in aid of finite element technique. That was done within two non- mixed dielectric liquids (Normal-Hexane and Acetone) located between two electrodes in pin - plane configuration. The output results show that, the path of the streamer was affected by the interface between the two liquids; the streamer path crosses this interface under some conditions such as the permittivity of the liquids and the distance between this interface and the tip of the pin. Under other conditions, the streamer path grows along the interface. The results were assisted by the development of the potential and the electric field distributions with the growth of the streamer propagation within the configuration
Dielectric barrier discharges (DBD) can be described as the presence of contact with the discharge of one or more insulating layers located between two cylindrical or flat electrodes connected to an AC/pulse dc power supply. In this work, the properties of the plasma generated by dielectric barrier discharge (DBD) system without and with a glass insulator were studied. The plasma was generated at a constant voltage of 4 kV and fixed distance between the electrodes of 5 mm, and with a variable flow rate of argon gas (0.5, 1, 1.5, 2 and 2.5) L/min. The emission spectra of the DBD plasmas at different flow rates of argon gas have been recorded. Boltzmann plot method was used to calculate the plasma electron temperature (Te), and Stark broadeni
... Show MoreSince there is no market for bond issuance by companies in the Iraqi market and the difficulty of borrowing, companies must resort to proprietary financing to finance their investments. However, in the framework of the literature of financial management, the type of financing used by the company sends signals to investors and therefore reflected on the market value. Therefore, the problem of the study revolves around the variables of the study (Equity financing within the framework the signal theory, price of common stock in the Iraqi market).
The study aims to verify the impact of the capital increase through the issuance of new stock on the price of
... Show MoreOne of the globalization results is (VAT) , so it is important to consider its results and impact on the tax system.
The Iraqi economy having wittnisd an acute transition period , still in need for a better care in aim to back it, especialy from the tax system.
The research is concerned with the (VAT) and its details –And for five chapters all the problomes connect are displayed .But yet the new system does not comply with the modern development and this is one of the defects of (VAT) in Iraq.
The history of (VAT)was also studied mentiorned and studied.
As a conclusion (VAT) is one of the m
... Show MoreWe studied at the morphology, structural setup, and optical characteristics of thin cadmium (CdSe) films a thickness of 250 nm that were created by thermal evaporation over glass, The films exhibited a hexagonal shape were crystalline, and tended to form grains in the (111) crystallographic direction, according to the X-ray diffraction examinations. These characteristics were established using the investigation's findings. Through the use of thin films of CdSe doped with Ag at a concentration of 1.5%, the crystal structure orientations for pure CdSe (25.32, 41.84) and CdSe:Ag (25.39, 41.01) that were both pure as well as those that were doped with silver were both determined. The band gap of the optical spectrum decreased by 1.93–
... Show More
Phytoplankton assemblage in relation to physical and chemical characteristics of water in Al-Auda marsh of Maysan province southern Iraq was assessed from November 2012 to July 2013. Six sampling sites were chosen to examine all phytoplankton species in the study area. A total of 246 species and seventy-five genera have been recognized belonging to twelve phytoplankton classes as follows: Bacillariophyceae (106 taxa), Chlorophyceae (34 taxa), Euglenophyceae (29 taxa), Cyanophyceae (29 taxa), Conjugatophyceae (19 taxa), Mediophyceae (10 taxa), Cryptophyceas (5 taxa), Coscinodiscophyceae (4 taxa), Chrysophyceae (4 taxa), Dinophyceae (3 taxa), Trebouxiophyceae (2 taxa) whereas Compsopogonophyceae record
A total of 72 individuals of genus Pristina were sorted from aquatic plant, Ceratophyllum demersum L., and filamentous algae collected from three sites on Tigris River at Baghdad including: Al-Sarafiya area (S1), Al- Jadiriyah area (S2), and Al- Za´afaraniya area (S3). Four species were identified including P. longiseta, P. aequiseta, P. proboscidea and P. foreli, with percentags of 51.7 , 36.4, 1.1, and 10.5 % respectively. The first two species found in all sites , while , P. proboscidea found only in S1 and P. foreli only in S2.