New hydrazide compounds (A2) and (A9) were prepared from their corresponding esters (A1, A8) .These esters were also prepared from their precursors 5-ethoxy carbonyl-(4methoxyphenyl)-6-methyl-1,2,3,4-tetrahydropyrimidine-2-thione (A1) via multicomponent reaction type and from hippuric acid respectively. The hydrazide compounds were then allowed to react with some aldehydes forming the corresponding hydrazones (A3-7) and (A1014). The synthesized compounds were characterized by IR, 1H-NMR, 13C-NMR, and Mass spectroscopies and well discussed. .

Background: Orthodontic tooth movement is characterized by tissue reactions, which consist of an inflammatory response in periodontal ligament and followed by bone remodeling in the periodontium depending on the forces applied. These processes trigger the secretion of various proteins and enzymes into the saliva.The purpose of this study was to evaluate the activity of alkaline phosphatase (ALP) in saliva during orthodontic tooth movement using different magnitude of continuous orthodontic forces. Materials and Methods: Thirty orthodontic patients (12 males and 18 females) aged 17-23 years with class II division I malocclusion all requiring bilateral maxillary first premolar extractions were randomly divided into three groups according to t

This research involves design and simulation of GaussianFSK transmitter in UHF band using direct modulation of ΣΔ  fractional-N synthesizer with the following specifications:

Frequency range (869.9– 900.4) MHz, data rate 150kbps, channel spacing (500 kHz), Switching time 1 µs, & phase noise @10 kHz = -85dBc.

New circuit techniques have been sought to allow increased integration of radio transmitters and receivers, along with new radio architectures that take advantage of such techniques. Characteristics such as low power operation, small size, and low cost have become the dominant design criteria by which these systems are judged.

A direct modulation by ΣΔ  fractional-N synthesizer is proposed

Let R be a commutative ring with non-zero identity element. For two fixed positive integers m and n. A right R-module M is called fully (m,n) -stable relative to ideal A of , if for each n-generated submodule of Mm and R-homomorphism . In this paper we give some characterization theorems and properties of fully (m,n) -stable modules relative to an ideal A of . which generalize the results of fully stable modules relative to an ideal A of R.

Necessary and sufficient conditions for the operator equation I AXAX n*, to have a real positive definite solution X are given. Based on these conditions, some properties of the operator A as well as relation between the solutions X andAare given.

This research involves the synthesis of some sulphanyl benzimidazole derivatives (Ia-c), which were prepared from reaction of 2-mercaptobenzimidazole substituted benzyl halide, and structures were identified by spectral methods[FTIR, 1H-NMR and 13C-NMR].These compounds were investigated as corrosion inhibitors for carbon steel in 1M H2SO4 solution using weight loss, potentiostatic polarization methods; obtained results showed that the sulphanyl benzimidazole derivatives retard both cathodic and anodic reactions in acidic media, by virtue of adsorption on the carbon steel surface. This adsorption obeyed Langmuir’s adsorption isotherm. The inhibition efficiency of (Ia-c) ranging between (65-92) %. By using different Ib derivative conc

     In this research investigation, a total of eighteen diverse tetra- and penta-lateral cyclic compounds were synthesized. These included 1,3,4-thiadiazole, thiazolidin-4-one (via an alternative method), 1,2,4-triazole, carbothioamide, thiazole-4-one, azetidin-2-one, and oxazole. The synthesis procedure entailed a sequence of reactions. The thiazolidine-4-one 1 was obtained by reaction p-aminobenzoic acid with thiosemicarbazide, followed by treatment with p-tolualdehyde to produce Schiff base 2. Reaction Schiff base 2 with mercaptoacetic acid in dry benzene was carried out to produce thiazolidine-4-one 3. In another synthesis pathway, the esterification of p-nitro benzoic acid with ethanol in the presence of sulfuric acid was

Biodiesel can be prepared from various types of vegetable oils or animal fats with the aid of a catalyst.
Calcium oxide (CaO) is one of the prospective heterogeneous catalysts for biodiesel synthesis. Modification
of CaO by impregnation on silica (SiO2) can improve the performance of CaO as catalyst. Egg shells and rice
husks as biomass waste can be used as raw materials for the preparation of the silica modified CaO catalyst.
The present study was directed to synthesize and characterize CaO impregnated SiO2 catalyst from biomass
waste and apply it as catalyst in biodiesel synthesis. The catalyst was synthesized by wet impregnation
method and characterized by x-ray diffraction, x-ray fluorescence, nitr

The 3-aminoacetophenone and 4-aminoantipyrine were used as ‎precursors to prepare new six ligands. The three new ligands (L1,L2 ‎and L3) were synthesis by reacting one mole of 3-aminoacetophenone ‎with one mole of (Acetyl chloride), (benzoyl chloride), (4-‎methoxybenzoyl chloride) and ammonium thiocyanat in acetone as a ‎solvent, they are:-‎ L1 (AAA) =[N-(3-acetylphenylcarbamothioyl)acetamide]‎ L2 (BAA) =[N-(3-acetylphenylcarbamothioyl)benzamide]‎ L3 (MAA) =[N-(3-acetylphenylcarbamothioyl)-4-methoxy benzamide]‎ Also three new derivatives of 4-aminoantipyrine were synthesis by ‎reacting one mole of 4-aminoantipyrine with one mole of (Acetyl ‎chloride), (benzoyl chloride), (4-methoxybenzoyl chloride) and ‎ammonium thio