The present study considers an influence of WS2 nanoparticles lubricants on physical characteristics of wrought Aluminium alloys. It is investigated parameters-performance relationship via tribological pin-on-disc tests, the pin is made of Aluminium alloys and the disk is made of AISI.1045, and the humidity was 70%. Oils with WS2 nanoparticles and without them reveal the loss rate of wear. In this study, the coefficient of friction (CoF) is reduced from 0.27 to 0.22 and the wear rate decreased from 0.128 x 10-6 Nm-1 to 0.107 x 10-6 Nm-1 at a load of 20 N. All worn surfaces were typically three types in wear mechanisms such as adhesive, abrasive, and oxidative wear. In addition, the use of nanoparticle enhanced the viscosity. This study showed promising results and concluded that the wrought Aluminium alloy to be the superior with WS2 nanoparticles, Furthermore, the wear rate has been reduced of 14% comparison without the use of WS2.
El estudio se clasifica dentro los estudios teóricos sobre literatura que se ocupa del estudio de los métodos de la crítica literaria: El Estructralismo literario francés y el Formalismo ruso del siglo XX que se utilizan en la interpretación literaría. Las dos corrientes literarias estudian la literatura como ciencia que busca aplicar un método científico al estudio de la literatura. Dicho estudio trata de exponer las teorías críticas que surgen en el debate de la interpretación de los textos literarios como el de Susan Sontag, Ricoeur Paul y Mijail Bajitin, etc. Además se incluye algunos ejemplos implican el análisis estructuralista y formalista como Kafka y la tragedia Judía. y Sur Racine.
ABSTRACT:
... Show MoreLas diferencias entre el pretérito perfecto simple y el imperfecto son uno de los temas más complejos de la lengua española, no sólo para el estudiante, sino para el profesor, puesto que sistematizar los casos y hacerlos fácilmente comprensibles al alumno es tarea difícil. Los profesores de lengua, cuyas investigaciones han dado lugar a una serie de teorías y de corrientes metodológicas y didácticas que permiten enfocar la enseñanza de una lengua extranjera de manera muy distinta a como se hacía tradicionalmente. Vamos a repasar muy brevemente cuáles son estas teorías.
En primer lugar es necesario señalar en qué consiste el aprendizaje de una segunda lengua:
"El aprendizaje de una segunda lengua (L2) es el
... Show MoreNew Schiff base [3-(3-acetylthioureido)pyrazine-2-carboxylic acid][L] has been prepared through 2 stages, the chloro acetyl chloride has been reacting with the ammonium thiocyanate in the initial phase for producing precursor [A], after that [A] has been reacting with the 3-amino pyrazine-2-carboxilic acid to provide a novel bidentate ligand [L], such ligand [L] has been reacting with certain metal ions in the Mn(II), VO(II), Ni(II), Co(II), Zn(II), Cu(II), Hg(II), and Cd(II) for providing series of new metal complexes regarding general molecular formula [M(L)2XY], in which; VO(II); X=SO4,Y=0, Co(II), Mn(II), Cu(II), Ni(II), Cd(II), Zn(II), and Hg(II); Y=Cl, X=Cl. Also, all the compounds were characterized through spectroscopic techniques [
... Show MoreInnovative various Schiff bases and their Co(II), Ni(II) and Cu(II) and Hg(II) compounds made by the condensation of 4-amino antipyrine with derived aminobenzoic acid (2-aminobenzoic acid, 3-aminobenzoic acid, and 4-aminobenzoic acid ) have been prepared by conventional approaches. These complexes were described by magnetic sensibility analysis, FT-IR spectra, and molar-conductance and elemental analysis. Analytical values appeared which the mixed-ligand complexes presented ratio about 2:1 (ligand: metal) with the chelation 4 or 6. The prepared compounds offered a good effect on the organisms; bacteria Staphylococcus-aurous, Escherichia-coli and fungi C. albicans, A. niger. Also, the biological products signalize which the mixed compl
... Show MoreThe eaction of 2 4 .6-trihydroxyactophenonemonohydra1e with
l hydr.azine monohydrate was realized ti·nder reflu.(( in methanol and i:l.
Jew drops of glacial acetic acid we.re added to give lhe'(int rmediate)
2-(1hydr pno-ctbyt)-benzcne-·1.3.5-r:Qql, which reacted wittl
saEcy.laldehyde. jn methm)ql to gjy;e 'a new :tyRe CNzOi) Ligand (H:flL]
f(2-{1-[(2-=bydroxy-bertzylide·ne)-bydrazqoo,J-e·thy.1}bcnze·neJ ;3·,5
|
Schiff base (methyl 6-(2- (4-hydroxyphenyl) -2- (1-phenyl ethyl ideneamino) acetamido) -3, 3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0] heptane-2-carboxylate)Co(II), Ni(II), Cu (II), Zn (II), and Hg(II)] ions were employed to make certain complexes. Metal analysis M percent, elemental chemical analysis (C.H.N.S), and other standard physico-chemical methods were used. Magnetic susceptibility, conductometric measurements, FT-IR and UV-visible Spectra were used to identified. Theoretical treatment of the generated complexes in the gas phase was performed using the (hyperchem-8.07) program for molecular mechanics and semi-empirical computations. The (PM3) approach was used to determine the heat of formation (ΔH˚f), binding energy (ΔEb), an
... Show MoreThis study is a numerical analysis of the transition process from the second to the third mode in transformer oil. In this study, it was determined how to change from the second to the third mode, which is thought to be a precursor to the process of electrical breakdown, which results in a significant loss of electrical energy and harm to electrical devices and equipment. The initiation time, length, rate of propagation velocity, and radius of the streamer discharge were determined. The transition from the second to the third mode during the electrical discharge process may lead to the occurrence of an electrical breakdown, which is one of the greatest challenges facing scientists and engineers who deal with the
... Show MoreConcentration of natural occurring radioactive material (NORM) in Markazia Degasing Station in North Rumaila oilfield (NDS) was measured in this study. Then, radiological assessment due to existing of NORM in different samples including soil, sludge, scale, oil, and water collected from different stages of oil and gas production NDS was done. Radioactivity concentration of Ra-226, Th-232 and K-40 were measured using gamma spectrometry system based on HPGe detector with efficiency of 30%. The results show that some locations within NDS are contaminated with NORM. The activity in Bq/kg of Ra-226, Th-232 and K-40 range between 15.19 in oil to 68.73 in sludge, 8.5 in oil to 23.45 in sludge and 80.23 in oil to 319.73 in saline water samples r
... Show More