(4R)-2, 3-(2`-chloro-2`- carboxyl)-1, 3-dioxolano-4- (2- dimethyl –dioxolane -yl) ascorbic acid (HL), a derivative of L-ascorbic acid was prepared by the reaction of 5,6-O-isopropylidene–L-ascorbic acid with trichloroacetic acid in alkaline medium. Seven new metal ion complexes of this ligand (HL) were prepared through its direct reaction with the chlorides of Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Hg(II) ions respectively. The new ligand and its ion metal complexes were characterized applying elemental analyses,1H and 13C NMR, IR as well as UV-Visible spectra. Spectroscopic data showed that the ligand (C11H11O8Cl) was coordinated to the metal ions through the two oxygen atoms of the carboxyl group as abidentate ligand. Electrical conductivity and magnetic measurements were done at room temperature. Based on the obtained analytical data, the following molecular formulas for the prepared complexes are suggested; {[M(L)2(H2O)2]. xH2O where x = 0 for Mn(II), Ni(II), Cu(II);x = 2 for Co(II)}; [M(L)Cl(H2O)3] for Zn(II) and Cd(II); and [Hg(L)ClH2O]. Octahedral geometry is suggested for all the complexes, except for the (Hg) complex which shows a tetrahedral geometry. Theoretical calculations of the molecular structure of the new ligand (HL) and its metal complexes were carried out too, applying the semi-empirical computation methods PM3 and PM6.The calculation results confirmed the suggested structures of all complexes.
The zirconia ceramic restoration (ZCR) is used as substitutes for the metal-ceramic restoration. Clinical studies demonstrating of ZCRs showed a high fracture incidence of veneering layer than metal-ceramic restorations. This attributed to the low bond strength of zirconia to veneering ceramic as a result of lacking of glass content in its matrix. Surface treatment was proposed to improve the bonding strength between zirconia and veneering ceramic. Several studies revealed that some treatment such as airborne particle abrasion (APA) is responsible for generating chipping of veneering ceramic. The study aimed to develop a new zirconia coatings to increase bonding strength between zirconia substrate and veneering porcelain. Three groups of 15
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Background: Tetralogy of Fallot is the most common cyanotic congenital heart disease which represents about 8-10% of all congenital heart diseases. It is characterized by four morphological features, large malalignment ventricular septal defect, Pulmonary stenosis, Overriding of aorta, and Right ventricular hypertrophy. The infant with TOF does well for the first few months of life with minimal or no cyanosis. The cyanosis begins to increase with secondary slow increase in polycythemia as well. Hypercyanotic spells are the most common complicating features of TOF
Patients and methods: This is a retrospective study of 200 patients with Tetralogy of Fallot (TOF) referred to Ibn Al-Bitar Center for Car
The electronic press is one of the distinctive media due to its unique features such as instant publishing and interactivity, uses multimedia, the use of hypertext, the personalization of media content, getting echo of the media messages provision of electronic archive of previous numbers of the newspaper.
The richness theory means that media are different depending on its wealth aspects which distinguish it from other media. The aspects of wealth here represent the features that characterize online press and constitute factors of media richness.
The researcher studies the properties of Iraqi media richness of their users. The researcher uses a field study to get the goals of the research and tests the hypotheses of media ric
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The subgrade soil is the foundation plate form of the roadway; it should sustain its structural characteristics throughout the design life of the roadway with minimal requirements for maintenance. When Gypseous soil is implemented in the construction of subgrade, problems regarding collapsibility and poor structural capacity usually occur when the subgrade came in touch with excess water. Asphalt stabilization could furnish a proper solution to such problems. In this investigation, an attempt has been made to monitor the variations in compressibility characteristics of asphalt stabilized subgrade soil subjected to 30 cycles of (freezing-thawing) and (heating-cooling). Data have been observed after each 10 cycles, and compared with that of r
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The most important recommendations of this research are:-
1.The benefit of the other countries experiences about the transparency of the government performance, without depending on the transparency that imitating the other experiences; that may not fit with the Iraqi government units.
2.The Ministry of Finance has to prepare the citizen guidebook about the government performance which is considered an essential document, it should be simple and available for all the parties of relation; and for not specialized citizen for the purpose of simplifying the understanding of government performance details.
3.The benefit of the government units websites of inte
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A total of 533 specimens were collected in survey of Brachyceran species from different regions of Iraq during February to November 2014 .This study was reported 16 species belonging to 13 genera and 7 families, the results showed that Dicranosepsis Duda, 1926 (Family; Sepsidae) is recorded the genus for the first time in Iraq.