This paper considers and proposes new estimators that depend on the sample and on prior information in the case that they either are equally or are not equally important in the model. The prior information is described as linear stochastic restrictions. We study the properties and the performances of these estimators compared to other common estimators using the mean squared error as a criterion for the goodness of fit. A numerical example and a simulation study are proposed to explain the performance of the estimators.
A new method for determination of allopurinol in microgram level depending on its ability to reduce the yellow absorption spectrum of (I-3) at maximum wavelength ( ?max 350nm) . The optimum conditions such as "concentration of reactant materials , time of sitting and order of addition were studied to get a high sensitivity ( ? = 27229 l.mole-1.cm-1) sandal sensitivity : 0.0053 µg cm-2 ,with wide range of calibration curve ( 1 – 9 µg.ml-1 ) good stability (more then24 hr.) and repeatability ( RSD % : 2.1 -2.6 % ) , the Recovery % : ( 98.17 – 100.5 % ) , the Erel % ( 0.50 -1.83 % ) and the interference's of Xanthine , Cystein , Creatinine , Urea and the Glucose in 20 , 40 , 60 fold of analyate were also studied .
6-(2-benzathiazolyl azo),-3,5-dimethylphenol was formed by grouping the 2- benzothiazole diazonium chloride with 3,5-dimethylphenol. Azo ligand(L) was resolved on the origin by 1H and 13CNMR, FTIR and UV-V is spectral analysis. Complexation of tridentate ligand (L) with Co2+, Ni2+, Cu2+ and Zn2+ in aqueous of ethyl alcohol with a 1:2 metal:ligand, and at ideal pH.. The formation of metal chelates are assigned using flame atomic, absorption, FTIR, and UV-Vis spectral analysis, other than conductivity and magnetic estates. The nature of the metal chelates were carried out by mole ratio and continuous, variation mechanism, Beer's law, followed the rate (0.0001 - 3×0.0001 M) concentration., High molar, absorptivity, for the complex solutions w
... Show MoreThe increasing demand for energy has encouraged the development of renewable resources and environmentally benign fuel such as biodiesel. In this study, ethyl fatty esters (EFEs), a major component of biodiesel fuel, were synthesized from soybean oil using sodium ethoxide as a catalyst. By-products were glycerol and difatty acyl urea (DFAU), which has biological characteristics, as antibiotics and antifungal medications. Both EFEs and DFAU have been characterized using Fourier transform infrared (FTIR) spectroscopy, and 1H nuclear magnetic resonance (NMR) technique. The optimum conditions were studied as a function of reaction time, reactant molar ratios, catalyst percentage and the effect of organic solvents. The conversion ratio of soybea
... Show More4-(((4-hydroxy-3,5-dimethoxybenzyl)oxy)methyl)benzoic acid was synthesized from multisteps and converted to their corresponding hydrazide. The corresponding hydrazide was cyclized to their corresponding 5-amino-1,3,4-oxadizole. Newly Schiff bases (7a-7e) were synthesized from reaction the 5-amino-1,3,4-oxadizole with several substituted of 4-hydroxybenzylaldehyde. The resulting compounds were characterized based on their IR, 1H-NMR, 13C-NMR, and HRMS data. 2,2-Diphenyl-1-picrylhydrazide (DPPH) and ferric reducing antioxidant power (FRAP) assays were used to test the antioxidant properties of the synthesized compounds. Compound 7d and 7e exhibited significant free-radical scavenging ability in both assays.
This study is included the preparation of two tetradentate amide-thiol proligands of the general structure [H2Ln], [where; (n = (1–2)]. The ligands [H2L1] and [H2L2] have been prepared from the reaction of the cyclic thioester 2-oxo-1, 4-dithiacyclohexane (compound 1) and 3-chloro-2-oxo-1, 4 dithiacyclohexane (compound 2) with 2-aminomethanepyridine in (1:1) ratio respetively. The reaction was carried out in chloroform at room temperature and under N2 atmosphere. Structural formula of these two ligands have been reported.
Ortho amino hydrazobenzene (L) has been prepared from the reaction of ortho amino phenyl thiol with phenyl hyrazan in mole ratio(1:1). It has been characterized by elemental analysis (C, H, N), IR, UV–Vis. The complexes of the bivalent ions (Co, Ni, Cu, Zn, Pd, Cd, Hg and Pb) and the trivalent (Cr) have been prepared and characterized too. The structural have been established by elemental analysis(C,H,N), IR , UV – Vis spectra , conductivity measurements , atomic absorption and magnetic susceptibility . The complexes showed characteristic behaviour of octahedral geometry around the metal ion and the( N,N) ligand coordinated in bidentate modeexcept with pd showed square planer. ? ,kf , ?max for the complexes were estimated too .
... Show MoreThe present work focuses on the changing of the structural characteristics of the grown materials through different material characterization methods. Semiconductor CdSxSe 1-x nano crystallines have been synthesized by chemical vapor depostion. (X- ray Diffraction; XRD), (Field Emission Scanning Electron Microscopy; FESEM), measured the characterization of Semiconductor CdSxSe1-x nano crystallines. The optical properties of semiconductor CdSxSe1-x nanocrystallines have been studied by the photoluminescence (PL) (He-Cd pulsed ultraviolet laser at 325nm excitation wavelength) at room temperature. The results showed the change rule of photoluminsence peak at different S
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