X-ray phase analysis was used to analyse the composition of Pb8Na(2±x)(PO4)6 (lead-sodium apatite structure) with different X values (X values refer to changes in the excess or lack of sodium (2±X) in the apatite structure): -0.15, -0.10, -0.05, 0.00, +0.05, +0.10, and +0.15. The ceramic method (solid-state reaction) was used to synthesize all samples at a temperature of 800 °C. Many programs, such as match software (v.3), PDF-4 database (ICCD), and database PDF-4 (ASTM), were used to study the single phases. The least-squares method was used to calculate the unit cell parameters. Results have shown that the following compositions: Pb8Na2(PO4)6, Pb8Na1.95(PO4)6, Pb8Na1.90(PO4)6, and Pb8Na1.85(PO4)6 contain only the pure phase of lead sodium apatite structure. On the other hand, the compositions of Pb8Na2.05(PO4)6, Pb8Na2.10(PO4)6, and Pb8Na2.15(PO4)6 showed other phases besides the phases of lead sodium apatite structure.
Conclusion The observation of the phenomenon of structural evolution of the international system and its instability on a particular situation, by its transition from unipolar to polarity to bipolarism and then to unilateralism in the early 1990s led by the United States, and to the present moment, To say that the structure by which the hierarchy of superpowers or the regime is directed in terms of its various capacities that qualify it, and with the consent of the rest of the States directing the regime to lead and lead the world's first place, has no direct relation to the stability of this system, I hope other more influential in its stability. The structure of the new international order will be completely different in terms of the r
... Show MoreBiosorption is an effective method to remove toxic metals from wastewaters. In this
study biosorption of lead and chromium ions from solution was studied using
Citrobacter freundii and Citrobacter kosari isolated from industrial wastewater. The
experimental results showed that optimum grwoth temperature for both bacteria is 30oC
and the optimum pH is 7 &6 for C. freundii and C. kosari respectively. While the
optimum incubation period to remove Pb and Cr for C. freundii and C. kosari is 4 days
and 3days respectively. Also the biosorption of Pb and Cr in mixed culture of bacteria
and mixed culture of Pb and Cr was investigated. Result indicate that uptake of Cr and
Pb for C.freundii, C. kosari and in mixes cultu
Biosorption is an effective method to remove toxic metals from wastewaters. In this
study biosorption of lead and chromium ions from solution was studied using
Citrobacter freundii and Citrobacter kosari isolated from industrial wastewater. The
experimental results showed that optimum grwoth temperature for both bacteria is 30oC
and the optimum pH is 7 &6 for C. freundii and C. kosari respectively. While the
optimum incubation period to remove Pb and Cr for C. freundii and C. kosari is 4 days
and 3days respectively. Also the biosorption of Pb and Cr in mixed culture of bacteria
and mixed culture of Pb and Cr was investigated. Result indicate that uptake of Cr and
Pb for C.freundii, C. kosari and in mixes cultu
In this contribution, new derivatives of bicyclic fused rings with bridgehead nitrogen of 3-substituted imidazo/pyrimidine derivatives A1-A3 were synthesized by reacting 2-aminobenzothiazol, acetyl acetone, and different substituted aldehydes in a one-pot reaction. These compounds A1-A3 were then condensed with 4-bromobenzaldehyde and 4-(N,N-dimethylamino)benzaldehyde to form new chalcone derivatives A4-A9. Ring closure of these compounds A4-A9 with urea and malononitrile afforded new oxopyrimidine derivatives A10-A15 and cyanopyridine derivatives A16-A21, respectively. These compounds were characterized by FT-IR, 1H NMR, and 13C NMR spectroscopy. The second part of this work included some of the i
... Show MoreThe accelerating effect of 1,4- phenylenediamine (PDA) additions in 1M hydrochloric acid solution at temperature rang (20-60) C° has been studied by weight losses measurement during ranging time (1-260) h and by following the pb2+ concentration in solution after several times by using Atomic absorption spectroscopy (AAS) . The volume of hydrogen gas involving was followed also in presence and absence of (PDA) in the corrosive solution .Accelerating enhanced by adding (NaCl , NaBr , NaI ) was also investigated.
Excess molar volumes of five ternary mixtures of 2- methoxy ethanol(1) +butyl acetate(2)+benzene(3), +toluene(3), +chlorobenzene(3), +bromobenzene(3), and +nitrobenzene(3) have been measured at 303.15K. The excess molar volume exhibited positive deviation over the entire range of composition in the systems 2-methoxy ethanol(1)+ butyl acetate(2)+ benzene(3),+toluene(3) and sigmoid behavior in the case of the remaining systems. Flory's statistical theory have been extended to predict the excess molar volumes of the five ternary mixtures at 303.15 k over a wide range of composition . An excellent agreement has been found between the experimental and theoretical excess molar volumes , both in magnitude and sign .
The experiment was carried out in the green house of botanical garden belong to Department of Biology/College of Education for Pure Science Ibn AL-Haitham, University of Baghdad for growing season 2017-2018 to evaluate effect of lead stress with concentrations (0, 50, 100, 150) mg.L -1 and Selenium concentrations (0, 15, 30) mg.L-1 on growth of dill plant using pots. The experiment was designed according to completely randomized design (CRD) with three replications. Result indicated that dill plants subjected to lead stress with height concentrations caused decrease in plant parameters (plant height, no. of branches. plant-1, root length, shoot dry weight, the content of nitrogen, phosphorus and potassium, protein concentration, no. of umbe
... Show MoreThe research aims to identify the relationship between spatial ability and the physical structure of concepts to the students of the Faculty of Education for Pure Sciences / Ibn al-Haitham، research involved students from the third class / morning study for the year 2011/2012 totaling (98) male and female students ،distributed into three groups which were selected randomly . The number of students (26 males and females) represented research sample after excluding repeaters and absentees، the research included two tests ; one test of spatial ability، which included (20) items and other test the physical structure of concepts، which included (12) items distributed into four domains ، the first (linking b
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