Enol-Keto tautomerism in 1-[(E)-1,3-benzothiazol-2-ylazo]naphthalen-2-ol has been studied using the B3LYP functional of density functional theory (DFT) with 6-31G(d,p) basis set. Relative and absolute energies, transition state geometries (TS), dipole moments, entropies, enthalpies and Gibbs free energies, equilibrium constants (K_T) and rate of tautomerization (k_r) were calculated. Also, the computations of geometries and vibration frequencies for the tautomers were calculated and compared. The results of the calculations showed that the enol form is the most stable form than other isomers, this might be due to intra-hydrogen bonding. The TS1 activation energies for tautomer A ↔ B, ta

Abstract

The current research aims to identify the impact of triangular bridging strategy in the acquisition of sociology of fourth-stage students. To achieve the research objective, the following null hypotheses were adopted: there are no statistically significant differences at a significance level (0, 05) between the average grades of the experimental group students who studied the triangular bridging strategy in acquiring concepts of sociology and average grades of the control group. The researcher has selected the fourth-stage students from Alexandronah School for girls that s related to the Directorate General of Baghdad the sample consisted of (87) students at litera

     This paper aims to introduce the concepts of  -closed, -coclosed, and -extending modules as generalizations of the closed, coclossed, and extending modules,  respectively. We will prove some properties as when the image of the e*-closed submodule is also e*-closed and when the submodule of the e*-extending module is e*-extending. Under isomorphism, the e*-extending modules are closed. We will study the quotient of e*-closed and e*-extending, the direct sum of e*-closed, and the direct sum of e*-extending.

In this study, poly4-(nicotinamido)-4-oxo-2-butenoic acid (PNOE) was prepared by the electro polymerization of 4-(nicotinamido)-4-oxo-2-butenoic acid (NOE) monomer on a 316 stainless steel (St.St) which acts as an anticorrosion coating.  Fourier transforms infrared (FTIR), atomic force microscopy (AFM), scanning electron microscopy (SEM), and cyclic voltammetry were used to diagnose the structure and the properties of the prepared polymer layer. The corrosion behavior of the uncoated and coated 316  St.St were evaluated by using an electro chemical polarization technique in 0.2 M hydrochloric acid  solution as a corrosive medium at a temperature range of 293 to 323 K. Nano materials, such as nano ZnO and graphene were adde

Background: Lack of durability of the bond of the dental adhesive systems to tooth structure is one of the most important problems in tooth colored restorative work. This in vitro study was performed to evaluate the effect of 2% chlorhexidine gluconate(CHX) on dentin bond strength by using total etch adhesive system at twenty-four hours and three months of water storage. Material and methods:A flat dentin surface was prepared for forty sound human maxillary premolar teeth which were acid etched with 36% phosphoric acid gel after being divided randomly into four groups of ten teeth each according to storage time and CHX application, theCHX was applied for 60 seconds before adhesive application for groups I and III which were tested after twe

: Partial purification of phosphoenolpyruvate carboxykinase (PEPCK) from type 2 diabetic patients sera take place using some purification steps such as participation with ammonium sulphate (55-80%) and filtered through dialysis, then ion exchange chromatography by DEAE sepharose anion column, gel filtration chromatography by sephadex G-100 column. In ion exchange step, there are four peak are obtained, the highest enzyme activity obtained by (0.4 M Nacl) with purification fold (2.18), yield (44.3) of enzyme and specific activity (13.5) mg/ng, which obtained a single peak by gel filtration chromatography, the degree of purification (5.34) fold, yield of enzyme (20%) with specific activity (33.109mg/ng). The purified enzyme had an optimum tem

This Research Tries To Investigate The Problem Of Estimating The Reliability Of Two Parameter Weibull Distribution,By Using Maximum Likelihood Method, And White Method. The Comparison Is done Through Simulation Process Depending On Three Choices Of Models (?=0.8 , ß=0.9) , (?=1.2 , ß=1.5) and (?=2.5 , ß=2). And Sample Size n=10 , 70, 150 We Use the Statistical Criterion Based On the Mean Square Error (MSE) For Comparison Amongst The Methods.

New 1,2,4-triazole derivatives of 2-mercaptobenzimidazole (MB) are reported. Ethyl (benzimidazole-2-yl thio) acetate (1) has been prepared by condensing 2-mercaptobenzimidazole with ethylchloroacetate. The ester (1) on reacting with hydrazine hydrate gave the corresponding acetohydrazide(2)which was reacted separately with phenylisocyanate and phenylisothiocyanate, followed by ring closure in an alkaline medium giving 3-[(benzimidazole-2-yl thio) methyl]-4-phenyl-1,2,4-triazole-5-ol and 3-[(benzimidazole-2-yl thio) methyl]-4-phenyl-1,2,4-triazole-5-thiol respectively (6,7). Reaction of acetohydrazide (2) with CS2 and ethanol/KOH, gave dithiocarbazate salt (8). Cyclization of (8) with hydrazine hydrate gave 3-[(benzimi

Complexes of some metal ions with 2-thiotolylurea were prepared in ethanolic medium using (1:1) (Metal : Ligand) ratio yielded series of neutral complexes as the general formula [M(L)Cl2]. The prepared complexes were identified by atomic absorption FT.IR, UV-Visble spectra, molar conductivity and magnetic properties. From the above data the tetrahedral structure was suggested for all complexes.