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.
Platinum (Pt) supported on sulfated zirconia (SZ) and HY-zeolite as a solid acid catalyst was synthesized successfully for isomerization reaction using precipitation and impregnation method. The physicochemical properties of the catalyst were characterized using various techniques including X-ray diffraction (XRD), Fourier transformation infra-red spectroscopy (FTIR), BET Surface area and pore volume, and Field Emission Scanning Electron Microscopy (FESEM). The prepared composite catalyst Pt/SZ-HY consisted of high Bronsted acidic sites and Lewis acidic sites. The addition of multi-walled carbon nanotubes (MWCNTs) to SZ increased the surface area and pore volume, resulting in smaller crystal sizes and a narrower particle size dist
... Show MoreBackground: Esthetic treatment is the options of patient seeking orthodontic treatment. Therefore this study was conducted to measure the concentration of Aluminum, Nickel, Chromium and Iron ions released from combination of monocrysralline brackets with different arch wires immersed in artificial saliva at different duration, to evaluate the corrosion point on different parts of the orthodontic appliances before and after immersion in artificial saliva, and to evaluate the corrosion potential of each group of the orthodontic appliances. Material and methods: Eighty orthodontic sets prepared. Each set represents half fixed orthodontic appliance, from the central incisor to the first molar, for the maxillary arch, each set consisted of molar
... Show MoreBinary relations or interactions among bio-entities, such as proteins, set up the essential part of any living biological system. Protein-protein interactions are usually structured in a graph data structure called "protein-protein interaction networks" (PPINs). Analysis of PPINs into complexes tries to lay out the significant knowledge needed to answer many unresolved questions, including how cells are organized and how proteins work. However, complex detection problems fall under the category of non-deterministic polynomial-time hard (NP-Hard) problems due to their computational complexity. To accommodate such combinatorial explosions, evolutionary algorithms (EAs) are proven effective alternatives to heuristics in solvin
... Show MoreThe present studies are focused on the modification of the properties of epoxy resin with different additives namely aluminum, copper by preparing of composites systems with percentage (20%, 40% and 50%) of the above additives. The experimental results show that the D.C of conductivity on wt% filler content at ( 293-413 ) K electrical conductivity of all above composites increased with temperature for composites with filler contact and find the excellent electrical conductivity of copper and lie between (2.6*10-10 - 2.1*10-10)?.cm . The activation energy of the electrical conductivity is determined and found to decrease with increasing the filler concentration.
In this work, the copper metal was treated using Nd:YAG laser with energy 1Joul to enhance corrosion resistance and improve surface properties. The copper metal has many applications in industry as well as water, oil and gas pipes. The same conditions, (laser power density, scan speed, distance between paths, medium gas-air) were applied in the laser surface treatment, After laser treatment, the samples microstructures were investigated using optical microscope (OM) to examine micro structural changes due to laser irradiation. Specimen surfaces were investigated using atomic force microscopy (AFM), X-ray diffraction (XRD), macro hardness, and corrosion test before and after laser treatment to
... Show MoreAspartate aminotransferase was purified from urine and serum of patients with type 2 diabetes in a 2 steps procedure involving dialysis bag and sephadex G-25 gel filtration (column chromatography). The enzyme was purified 346.23 fold with 1467% yield and 3.46 fold with 142.85% yield in urine and serum of patients with type 2 diabetes respectively. The purified enzyme showed single peak. The results of this study revealed that AST activity of type 2 diabetes urine and serum increased significantly (p<0.001) compared with control group.
Three types of zeolite A were prepared from Iraqi kaoline which are 3A, 4A and 5A by ion exchange method .They were characterized by XRD and atomic absorption techniques .They were used as adsorbents to examine their applicability for H2S adsorption .The adsorption process was performed in a static form and constant volume system which constructed from stainless steel .The effect of zeolite type and temperature on the adsorption properties of H2S at -5 , 25 and 55 oC was studied .The zeolite type 5A has the highest adsorption value (79.384 µmol/g ) and the three types may be arranged in a sequence toward H2S adsorption as 5 A> 4A>3A .The amount of H2S adsorbed increased as temperature decreased from 55 to -5 for all samples. Langmuir , Fre
... Show MoreA substantial matter to confidential messages' interchange through the internet is transmission of information safely. For example, digital products' consumers and producers are keen for knowing those products are genuine and must be distinguished from worthless products. Encryption's science can be defined as the technique to embed the data in an images file, audio or videos in a style which should be met the safety requirements. Steganography is a portion of data concealment science that aiming to be reached a coveted security scale in the interchange of private not clear commercial and military data. This research offers a novel technique for steganography based on hiding data inside the clusters that resulted from fuzzy clustering. T
... Show MoreThis work provides an analysis of the thermal flow and behavior of the (load-free) refrigerator compartment. The main goal was to compare the thermal behavior inside the refrigerator cavity to the freezer door (home refrigerator) effect and install a fan on the freezer door while neglecting the heat transmitted by thermal radiation. Moreover, the velocity distribution, temperature, and velocity path lines are theoretically studied. This was observed without affecting the shelves inside the cabinet and the egg and butter places on the refrigerator door as they were removed and the aluminum door replaced with a glass door. This study aims to expand our knowledge about the temperature and flow fields of this refrigerator mo
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