The study aims to investigate the effect of Al2O3 and Al additions to Nickel-base superalloys as a coating layer on oxidation resistance, and structural behavior of nickel superalloys such as IN 738 LC. Nickel-base superalloys are popular as base materials for hot components in industrial gas turbines such as blades due to their superior mechanical performance and high-temperature oxidation resistance, but the combustion gases' existence generates hot oxidation at high temperatures for long durations of time, resulting in corrosion of turbine blades which lead to massive economic losses. Turbine blades used in Iraqi electrical gas power stations require costly maintenance using traditional processes regularly. These blades are made of nickel superalloys such as IN 738 LC(Inconel 738). Few scientists investigated the impact of Al2O3 or Al additions to Nickel-base superalloys as coating layer by using the slurry coating method on oxidation resistance to enhance the Nickel-base superalloy's oxidation resistance. In this study, IN 738 LC is coated with two different coating percentages, the first being (10 Al+90 Al2O3) and the second being (40 Al+60 Al2O3). Scanning Electron Microscope (SEM) and X-Ray Diffraction (XRD) were performed on all samples before and after oxidation. According to the results, SEM images of the surface revealed that the layer of the surface has a relatively moderated porosity value and that some of the coating layers contain micro-cracks. The best surface roughness of specimens coated with 60 % alumina+40 % aluminum was 5.752 nm. Whereas, the surface roughness of specimens coated with 90 % alumina+10 % aluminum was 6.367 nm.Results reveal that alloys with both Al2O3 and Al additions have reported a positive synergistic effect of the Al2O3and Al additions on oxidation resistance. Moreover,the NiCrAl2O3 thermal coating has good oxidation resistance and the effective temperature of anti-oxidation is raised to 1100 °C in turn reducing the maintenance period of turbine blades
Communicative-based textbooks are developed and disseminated throughout the country.
However, it is difficult for teachers who themselves have learnt English through the traditional
approaches to suddenly be familiar with CLT (Communicative Language Teaching) principles
and teach communicatively. Therefore, many teachers remain somewhat confused about what
exactly CLT is and others familiar with CLT but unable to achieve communicative classroom
teaching. Consequently, those teachers need to be introduced to the CLT principles and they need
training in how to put CLT principles into practice. Accordingly, this study aims to find out the
effect of combining video lectures and Kolb experiential learning on EFL student-t
The existing investigation explains the consequence of irradiation of violet laser on the optic properties of (CoO2) films. The film was equipped by the utilization of semi-computerized spray pyrolysis technique (SCSPT), it is the first time that this technique is used in the preparation and irradiation using a laser in this technique. From the XRD analysis, the crystalline existence with trigonal crystal system was when the received films were processed by continuous violet laser (405 nm) with power (1W) for different laser irradiation time using different number of times a laser scan (0, 6, 9, 12, 15 and 18 times) with total irradiation time(0,30,45,60,75,90 min
Experimental densities, viscosities η, and refractive indices nD data of the ternary ethanol+ n-hexane + 3-methyl pentane system have been determined at temperatures 293.15,303.15 and 313.15 K and at atmospheric pressure then these properties were calculated theoretically by using mixing rules for densities, viscosities and refractive indices .After that the theoretical data and the experimental data were compared due to the high relative errors in viscosities an equation of viscosity was proposed to decrease the relative errors.
In this work, prepared new ligand namely 5-(2,4-dichloro-phenyl)-1,3,4-oxadiazole-2-(3H)-thion, was obtained from the 2,4-dichlorobenzoyl chloride with hydrazine, after that reaxtion with CS2/KOH in methanol.
In this work lactone (1) was prepared from the reaction of p-nitro phenyl hydrazine with ethylacetoacetate, which upon treatment with benzoyl chloride afforded the lactame (2). The reaction of (2) with 2-amino phenol produced a new Schiff base (L) in good yield. Complexes of V(IV), Zr(IV), Rh(III), Pd(II), Cd(II) and Hg(II) with the new Schiff base (L) have been prepared. The compounds (1, 2) were characterized by FT-IR and UV spectroscopy, as well as characterizing ligand (L) by the same techniques with elemental analysis (C.H.N) and (1H-NMR). The prepared complexes were identified and their structural geometries were suggested by using elemental analysis (C.H.N), flame atomic absorption technique, FT-IR and UV-Vis spectroscopy, in additio
... Show MoreThis present work is concerned with one of the syntactic issues that has been researched by many linguists, grammarians, and specialists in Islamic studies, the estimated answer to a condition. However, this topic is researched this time by examining Imam Al-Qurtbi’s opinions in interpreting related ayas from the holly Quraan in his book (Collector of Quranic Rules) or its transliteration (Al-Jami’ Li Ahkam Al-Quran). Such a step involves commenting on, tracking what Al-Qurtbi said in this regard, discussing it from the points of view of other grammarians, and judging it accordingly, taking into account the apparent surface structures of the examples collected. To achieve this objective, the inductive analytical approach has be
... Show MoreA novel series of mixed-ligand complexes of the type, [ML1(L2)3]Clx [M= Cr(III), Fe(III), Co(II),Ni(II), Cu(II), Cd(II) and Hg(II), n = 2, 3], was synthesized using Schiff base (HL1) as main ligand, nicotinamide (L2) as secondary ligand, and the corresponding metal ions in 1:3:1 molar ratio. The main ligand, HL1 was prepared by the interaction of ampicillin drug and 4-chlorobenzophenone. The synthesized mixed ligand complexes were characterized by elemental analysis, UV-Vis, FT-IR,1H-NMR,13C-NMR and TG/DTG studies. In the mixed-ligand complexes, the Schiff base ligand, HL1 showed coordination to the central metal ion in tridentate manner via azomethine nitrogen, β-lactam ring oxygen and deprotonated carboxylic oxygen atoms, whereas the sec
... Show MoreA new Schiff base [1-((2-(1H-indol-3-yl)ethylimino)methyl)naphthalene-2-ol] (HL) has been synthesized by condensing (2-hydroxy-1-naphthaldehyde) with (2-(1H-indol-3-yl)ethylamine). In turn, its transition metal complexes were prepared having the general formula; [Pt(IV)Cl2(L)2], [Re(V)Cl2(L)2]Cl and [Pd(L)2], 2K[M(II)Cl2(L)2] where M(II) = Co, Ni, Cu] are reported. Ligand as well as metal complexes are characterized by spectroscopic techniques such as FT-IR, UV-visible, 13C & 1H NMR, mass, elemental analysis. The results suggested that the ligand behaves like a bidentate ligand for all the synthesized complexes. On the other hand, theoretical studies of the ligand as well its metal complexes were conducted at gas phase using Hyp
... Show MoreThe Iranian nuclear program was one of the most prominent issues in the international arena, in light of Iran's insistence on using it in various ways, and according to international changes, it came under pressure from the American side to impose packages of sanctions, which continued to our time, as it went to Russia and China to gain support in developing its nuclear activities. And, by virtue of the common interests that are linked between them, Iran has received great support from the last two countries in all fields to reach the final agreement in 2015, regarding asserting the peace of these activities, in addition to lifting all restrictions represented in the previous sanctions according to the Security Council resolutions, Aldo
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