Power-electronic converters are essential elements for the effective interconnection of renewable energy sources to the power grid, as well as to include energy storage units, vehicle charging stations, microgrids, etc. Converter models that provide an accurate representation of their wideband operation and interconnection with other active and passive grid components and systems are necessary for reliable steady state and transient analyses during normal or abnormal grid operating conditions. This paper introduces two Laplace domain-based approaches to model buck and boost DC-DC converters for electromagnetic transient studies. The first approach is an analytical one, where the converter is represented by a two-port admittance model via mode averaging and inclusion of switching effects. The second approach consists of reconstructing the two-port admittance model of the converter from terminal measurements for a series of tests. The performance of both approaches is evaluated against EMTP simulations, with very close results.
In this paper, we have been used the Hermite interpolation method to solve second order regular boundary value problems for singular ordinary differential equations. The suggest method applied after divided the domain into many subdomains then used Hermite interpolation on each subdomain, the solution of the equation is equal to summation of the solution in each subdomain. Finally, we gave many examples to illustrate the suggested method and its efficiency.
This study Achieved to search form the infections by Cholera and Diarrhea in two different areas from the side of Cultural, Social, Economical and Environmental field in Baghdad governorate, during a period from 3/10 – 3/12/2007.these were in Obiady city and Palestine street. This study included groups of patients who went to the Kindy Hospital lab. The researcher use a sample of (300) persons of different ages with range (150) persons in each city from the study city, in this study show a great different in the percentage of infection by parasites, helminthes, viruses, bacteria and vibrio cholera in the two city according to age groups, reach upper percentage by infection in age (1-10) years in Obiady city with percent (57.5 %) wh
... Show MoreIn this research, a modified artificial hand with direct control has been designed using electrical artificial muscle wires that receive direct sensory impulses through human hand instead of using the mechanical action to open and close this artificial hand. Each finger is designed as a chain and its movements achieved through the conventional arrangement control of the electrical muscles wires. The results indicate that it is possible to design an artificial hand using electrical muscle wire for control it with high accuracy.
Bored piles settlement behavior under vertical loaded is the main factor that affects the design requirements of single or group of piles in soft soils. The estimation of bored pile settlement is a complicated problem because it depends upon many factors which may include ground conditions, validation of bored pile design method through testing and validation of theoretical or numerical prediction of the settlement value. In this study, a prototype single and bored pile group model of arrangement (1*1, 1*2 and 2*2) for total length to diameter ratios (L/D) is 13.33 and clear spacing three times of diameter, subjected to vertical axial loads. The bored piles model used for the test was 2000
... Show MoreThe present study aimed to investigate the anatomy, histology, and immunohistochemistry of parathyroid gland in two Iraqi mammals (Weasel, Herpestes javanicus and Long-ear hedgehog, Hemiechinus auritus) as a comparative study. A total of (20) animal for each species were used in the present study. Animals collected were immediately anesthesia and dissected to get the parathyroid gland. Methods of Humason and Bancroft and Stevens were employed for histological techniques. Different stains were used (Hematoxylin- Eosin stain-(H & E), Periodic Acid Schiff stain-(PAS), Azan stain, and Methyl Blue stain-(MB)) for staining the histological sections. Anti-calcitonin, code140778 marker used for immune-histochemical study. Results of the present stu
... Show MoreThe methods used by the print media (press) is varied in conveying its messages and its orientations to the readers. But language takes the leading method among these methods, or a real competitor - so far - due to the characteristics and advantages of languages, including: ease, abbreviation, and development, etc.
In the midst of such events, political tensions, and what they carry of the global developments, and among which was the most important the fall of the former Iraqi regime in the spring of 2003, the press had the greatest share, and a large portion on the level of monitoring, analyzing, and interpreting the various consequences of the event. The interpreting of the news varies according to the evolving political trends
... Show MoreThis study deals with the time property in the cinema through two films: (The Knife) directed by Khalid Hamada and (The Deceived) directed by Tawfiq Saleh. These two films were excerpted by the cinema from two novels of the Palestinian writer Ghassan Kanafani, the first is from the novel (What is Left for You) and the second is from the novel (Men in the Sun). If the Palestinian novel has imposed its presence on the Arab creative scene through a group of novelists who took it upon themselves to communicate their cause to the world, the Palestinian cinema has been far from being a purely Palestinian, because many of the cinematic works have been provided by Arab countries on the issue, while this cinema is still seeking
... Show MoreThe research aims at a statement Internal Debt options during shocks and the impact of this borrowing in the volume of the foreign reserve, using induction and deduction with available data analysis. During the period (2004-2013) did not require the use of borrowing across (financial institutions, discounted transfers, bonds); it was only sufficient by transfer with commercial banks that can finance of temporary budget deficits: rose and decline of volume of foreign reserve according to the changes of oil prices and the volume of purchases and sales of the Central Bank of Iraq. Central Bank of Iraq (CBI) has significantly contributed to Internal Debt through bond and discounted transfers in the secondary market; thus, funding the
... Show MoreThis study has three parts, the first one is the synthesis of a novel Schiff bases by the condensation of guanine or 9-[{2-hydroxyethoxy}methyl]-9H-guanine with variety aldehydes to yield four different bases as follows: (E)-2-((4-nitrobenzylidene)amino)-1,9-dihydro-6H-purin-6-one (S1), (E)-2-((4-methoxybenzylidene)amino)-1,9-dihydro-6H-purin-6-one (S2), (E)-2-((2-hydroxybenzylidene) amino)-9-((2-hydroxy ethoxy)methyl)-1,9-dihydro-6H-purin-6-one (S3), and (E)-2-(((9-((2-hydroxy ethoxy)methyl)-6-oxo-6,9-dihydro-1H-purin-2-yl)imino)methyl)benzoic acid (S4). Then, spectroscopic analyses such as Elemental Analysis, UV/VIS, Mass spectra, FTIR, 1H,13C-NMR were made to recognize these bases. In the second part, the ability of synthesized bases to
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