Crude oil is one of the most important sources of energy in the world. To extract its multiple components, we need oil refineries. Refineries consist of multiple parts, including heat exchangers, furnaces, and others. It is known that one of the initial operations in the refineries is the process of gradually raising the temperature of crude oil to 370 degrees centigrade or higher. Hence, in this investigation the focus is on the furnaces and the corrosion in their tubes. The investigation was accomplished by reading the thickness of the tubes for the period from 2008 to 2020 with a test in every two year, had passed from their introduction into the work. Where the thickness of more than one point was measured on each tube in the same row and the corrosion rate was extracted for three furnaces, starting from the area of heat transfer by radiation to the heat transfer area of the convection in three different operating units. It was found that the highest percentage corrosion value between the standard tube thickness and the thickness of conduction position was 37% with the conduction zone, and 31% with radiation zone. There, the tubes specification was tested. Five percent Cr-0.5 Moly and the temperature of radiation zone was 578 °C to 613 °C and the stack temperature was 410 °C to 450 °C. So, the results show that the maximum erosion occur at the convection zone.
Despite the antiplaque effect of mouth-rinsing with a combination composed of miswak (Salvadora persica L.) and green tea (Camellia sinensis var. assamica) extracts, no data are available regarding its effect on gingival tissue at the molecular level. This pilot study aimed to assess the effect of oral rinsing with this combination on gingival crevicular fluid (GCF) flow and IL-1β levels. Ten subjects rinsed with either the combination, 0.12% chlorhexidine gluconate (CHX) or distilled water without toothbrushing for 4 days after receiving baseline polishing. GCF IL-1β concentration, influx, resting volume and plaque quantity were measured at baseline and after 4 days for each intervention. No significant differences in GCF flow or
... Show MoreAnew Schiff base (NaHL) has been prepared from the reaction between the salt of amino acid glycine with 2-hydroxy naphthaldehyde. By tridentate Schiff base of (ONO), donors were characterized by using U.V and spectrophotometer techniques. Complexes of Co(II) Ni(II) Cu(II) and Zn(II) ion with the ligand have been prepared, these complexes were identified by infrared, electronic spectral data, elemental analysis, magnetic moments, and molar conductivity measurements. It is concluded from the elemental analysis that all the complexes have (1:2) [metal:ligand] molar ratios, octahedral, with the exception to Zn(II) complex which have (1:1)[metal:ligand] molar ratio.
... Show MoreSYNTHESIS, CHARACTERIZATION, STRUCTURAL, THERMAL, POM STUDIES, ANTIMICROBIAL AND DNA CLEAVAGE ACTIVITY OF A NEW SCHIFF BASE-AZO LIGAND AND ITS COMPLEXATION WITH SELECTED METAL IONS
The objective of this study is to test In Vitro the twenty chemical compounds that contains Schiff base or oxazepine, indoline, imidazolo units in concentrations( 50, 100, 150) mg / dl as antifungal activity, against three pathogenic Candida species that occur in humans. We tested one isolates of
) Candida albicans ,Candida glabrata and Candida krusei). All these species affect human health . The study was carried out in the Laboratory of Public Health , directly of health for the period from May 2016 to April 2017 , Candida spp isolates used in this study were collected from patients admitted at some private c
... Show MoreA new, simple, sensitive and fast developed method was used for the determination of methyldopa in pure and pharmaceutical formulations by using continuous flow injection analysis. This method is based on formation a burgundy color complex between methyldopa andammonium ceric (IV) nitrate in aqueous medium using long distance chasing photometer NAG-ADF-300-2. The linear range for calibration graph was 0.05-8.3 mmol/L for cell A and 0.1-8.5 mmol/L for cell B, and LOD 952.8000 ng /200 µL for cell A and 3.3348 µg /200 µL for cell B respectively with correlation coefficient (r) 0.9994 for cell A and 0.9991 for cell B, RSD % was lower than 1 % for n=8. The results were compared with classical method UV-Spectrophotometric at λ max=280 n
... Show More2-(1,2-dihydroxy ethyl -1- (2-mercaptophenyl)-5-(2-mercaptophenyl imino)-2,5-dihydro-1H-pyrrol-3,4-diol(H2L`)a lactam derivative of L-ascorbic acid was prepared by reaction of 5,6-O-isopropylidene L-ascorbic acid with 2-amino thiophenol in a mole ratio of (1:2) respectinely. A series of new metal complexes of this ligand (H2L`) were prepared by a reaction with the chlorides of Cr(III), Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Hg(II). The new ligand and its metal complexes were characterized by C.H.N.,1H and 13C NMR, IR as well as UV-Visible spectra and mass spectra of Ni(II) and Zn(II) complexes was also done. Atomic absorption of the metal percentage, electrical conductivity and magnetic measurements at room temperature was ca
... Show MoreThe present work includes the preparation and characterization of{Co(II) , Ni(II), Pd(II), Fe(III) , Ru(III),Rh(III), Os(III) , Ir(III) , Pt(IV) and VO(IV)}complexes of a new ligand 4-[(1-phenyl-2,3-dimethyl-3-pyrozoline-5-one)azo]-N,N-dimethylanline (PAD). The product (PAD) was isolated,studies and characterized by phsical measurements,i.e., (FT-IR), (UV) Spectroscopy and elemental analysis(C.H.N). The prepared complexes were identified and their structural geometric were suggested in solid state by using flame atomic absorption, elemental analysis(C.H.N), (FT-IR) and (UV-Vis) Spectroscopy, as well as magnetic susceptibility and conductivity measurements . The study of the nature of the complexes formed in( ethanolic solution) following t
... Show MoreABSTRACT : This research involves the synthesis of five to seven heterocyclic compounds starting with Schiff’s bases which derived from oxime as a starting material. 1.3-oxazepine derivatives were prepared from adding different anhydrides to the Schiff bases, tetrazole and thiazolidinone derivatives synthesized from add sodium azide and thioglycolic acid to the same Schiff’s bases as a five members ring. Pyrimidine derivatives were prepared after the reaction of the azomethine group with acetyl chloride and then urea and thiourea to synthesis on derivatives contain the six members ring. Another step included identified and confirmed these compounds by FT- IR, 1HNMR, TLC and 13CNMR finally, step included the assay of biological activity
... Show MoreIn the present work the nuclear structure of even-even
Ba(A=130-136, Z=56) isotopes was studied using (IBM-1). The reduced matrix element of magnetic dipole moment (11 II f(Ml) II/,) and the magnetic dipole transitions probability B(M 1) were calculated
for one and two bodies of even-even Ba(A=lJ0-136, Z=56). A good
agreement had been found of present with available experimental data.
The current study was to examine the reliability and effectiveness of using most abundant, inexpensive waste in the form of scrap raw zero valent aluminum ZVAI and zero valent iron ZVI for the capture, retard, and removal of one of the most serious and hazardous heavy metals cadmium dissolved in water. Batch tests were conducted to examine contact time (0-250) min, sorbent dose (0.25-1 g ZVAI/100 mL and 2-8 g ZVI/100 mL), initial pH (3-6), pollutant concentration of 50mg/L initially, and speed of agitation (0-250) rpm . Maximum contaminant removal efficiency corresponding to (90 %) for cadmium at 250 min contact time, 1g ZVAI/ 6g ZVI sorbent mass ratio, pH 5.5, pollutant concentration of 50 mg/L initially, and 250 rpm agitation speed wer
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