129 research outputs found

    The Investigation of Structure-Activity Relationships of Tacrine Analogues: Electronic-Topological Method

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    In this study we investigated the structure-activity relationships by using the Electron- Topological Method (ETM) for a class of AChE inhibitors related to tacrine (9-amino-1,2,3,4-tetrahydroacridine) and 11 H-Indeno-[1,2-b]-quinolin-10-ylamine that tetracyclic tacrine analogues, a drug currently in use for the treatment of the AD. Molecular fragments being specific for active and inactive compounds were revealed by using ETM. The result of testing showed the high ability of ETM in predicting the activity and inactivity in investigated series

    Quantum Chemical Study on the Corrosion Inhibition of Copper Using Some Thiosemicarbazides and Tetrazoles

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    Relationships between corrosion inhibition efficiency of two thiosemicarbazide based compounds namely; 4-phenyl thiosemicarbazide (PTSC), Salicylaldehyde thiosemicarbazone (STSC) and 4 tetrazole derivative; 5-Mercapto-1-methyltetrazole (MMTA), 5-(3-Pyridyl)-1H-tetrazole (PyTA), 5-Amino-tetrazole mono hydrate (ATA) and 5-phenyl tetrazole (PTA) and their molecular electronic properties have been theoretically studied at the level .............(More details are available in the full paper) Keywords: Thiosemicarbazides and Tetrazoles, structural parameters DOI: 10.7176/CMR/11-2-04

    Corrosion Inhibition of Copper in Sea Water Using Derivatives of Thiosemicarbazides

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    Three corrosion inhibitors namely: 4-allyl-3-thiosemicarbazide C4H9N3 S, 4-(1-methyl)-3-thiosemicarbazide,4-tolyl-3-thiosemicarbazide were tested as corrosion inhibitors for copper in sea water environmnt.Copper samples were tested using potentiodynamic polarization technique in the absence and in the presence of corrosion inhibitors.   High inhibition efficiencies (≥95%) were shown by the tested inhibitors.  The best performance was shown by 4-tolyl-3-TSC

    Effect of Pickling and Activation Treatments on the Performance of Electroless Plating of Ni-B Coating on AZ31 Mg Alloy

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    Pickling is particularly critical before Ni-B electroless plating to create a uniform and catalytically active surface.  In the present work, pickling treatment of AZ31 Mg alloy was performed in phosphoric acid followed by immersion in 40% HF.  The effect of concentration of both H3PO4 and HF as well as the effect of time were investigated.   The pickled samples were then electroless plated with a Ni-B composite.  The performance of the Ni-B composite coating was investigated under the SEM.Results show that the highest quality coating was obtained upon pickling AZ31 Mg alloy samples in 50% phosphoric acid for 1 min, followed by activation in 40% HF for 15 min. Higher concentration of H3PO4 results in a higher concentration of PO3−4, leading to a higher tendency to produce insoluble films (mainly Mg3(PO4)2 and AlPO4) on the substrate surface slowing down the rate of Mg alloy oxidization and dissolution.  Activation of pickled AZ31 Mg samples in HF results in the formation of corrosion resistant dense layer of magnesium fluoride. SEM investigation predicted the electroless deposition of an adherent compact layer of Ni–B composite coating on the H3PO4/HF pickled AZ31 samples. Key Words: AZ31 Mg alloy, pickling, activation, HF, electroless plating DOI: 10.7176/CMR/11-5-04 Publication date:May 31st 201

    Electroless Plating of Ni-B Composite Coating on AZ31 Mg alloy

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    A Ni–B coating was electroless-deposited directly on H3PO4/HF pickled AZ31. The thickness of the plating layer was estimated through weight gain measurements and was affected by temperature, time and bath composition. The highest thickness was obtained at 6 g/L of NaHB4 at 85oC.  An adherent compact layer of Ni-B was obtained. Electrochemical impedance spectroscopy measurements in 3.5 wt.% sodium chloride aqueous solution suggest that the plating can protect the magnesium alloy substrate from corrosion attack

    Anodic and Cathodic preparation of MnO2/Co2O3 Composite Electrode Anodes for Electro-Oxidation of Phenol

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       The economical and highly performed anode material is the critical factor affecting the efficiency of electro-oxidation toward organics. The present study aimed to detect the best conditions to prepare Mn-Co oxide composite anode for the electro-oxidation of phenol. Deposition of Mn-Co oxide onto graphite substrate was investigated at 25, 30, and 35 mA/cm2 to detect the best conditions for deposition.  The structure and the crystal size of the Mn-Co oxide composite electrode were examined by using an X-Ray diffractometer (XRD), the morphological properties of the prepared electrode were studied by scanning electron microscopy (SEM) and Atomic force microscopy (AFM) techniques, and the chemical composition of the various deposited oxide was characterized by energy dispersive X-ray spectroscopy (EDX). The study also highlighted the effect of current density (40, 60, and 80 mA/cm2), pH (3, 4, and 5), and the concentration of NaCl (1, 1.5, and 2 g/l) on the anodic electro-oxidation of phenol was investigated.  The results revealed that the composite anodes are successfully prepared galvanostatically by anodic and cathodic deposition. In addition, the current density of 25 mA/cm2 gave the best cathodic deposition performance. The removal efficiency of phenol and other by-products increased as the current density and the concentration of NaCl in the electrolyte increased, while it decreased as the pH increased. The prepared composite electrode gave high COD removal efficiency (98.769 %) at the current density of 80 mA/cm2, pH= 3, NaCl conc. of 2 g/L within 3 h

    Developing a New Algorithm to Detect Right Thumb Fingernail in Healthy Human

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    Due to significant challenges faced by traditional methods of personal identification like fingerprinting, eye scanning, and voice recognition, new techniques are needed. One such approach involves the use of human nail images for identification and access to personal identification programs and electronic patient files. A novel algorithm, which consists of three stages, has been proposed utilizing the HSV color space detection algorithm, grayscale contrast optimization algorithm, nail segmentation, and image smoothing with a Gaussian filter. This method reduces tested image data and preserves the primary image structure, and has the potential to surpass the accuracy of traditional methods, providing an additional layer of security in personal identification programs and electronic patient files. Nail image detection can be conducted remotely and accessed through standard cameras or smartphones, making it a more hygienic and convenient option than physical contact methods such as fingerprinting or eye scanning. Moreover, the use of nail images for personal identification has several other benefits, especially in situations where traditional methods are not feasible, such as in individuals with skin conditions that prevent fingerprinting. The success of the proposed algorithm in detecting nail images for personal identification has implications beyond individual security and can be applied in different fields, including healthcare and forensic science, to improve identification accuracy and prevent fraud. For example, the use of nail images could help prevent identity theft in healthcare settings, where sensitive information is stored and exchanged

    Effect of Al2O3 and WO3 Ceramic Additives on the Surface Morphology and Mechanical Properties of Electroless Nickel-Boron Composite Coatings Fabricated on AZ31 Magnesium Alloy

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    In the present study, synthesis and a comparison of properties (structural and mechanical)  of  Ni–B and Ni–B–Al2O3 and Ni-B-WO3 composite coatings have been presented  to  elucidate the beneficial role  of Al2O3 or WO3 addition in  binary Ni–B coatings. The  Ni–B– Al2O3 and Ni-B-WO3 coatings were synthesized by  adding Al2O3 or NaWO3 powdered particles into the  above  mentioned Ni–B  coating solution.  A significant improvement in mechanical properties has been observed by the addition of Al2O3 or WO3 additions.  This novel composite coating composition will be useful for wear and corrosion applications. DOI: 10.7176/CMR/11-8-05 Publication date:October 31st 201
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