Catalytic removal of the S-content from thiophene is a central step in efforts aiming to reduce the environmental burdens of transportation fuels. In this contribution, we investigate the hydrodesulfurization (HDS) mechanisms of thiophene (C4H4S) over γ-Mo2N catalyst by means of density functional theory (DFT) calculations. The thiophene molecule preferentially adsorbs in a flat mode over 3-fold fcc nitrogen hollow sites. The HDS mechanism may potentially proceed either unimolecularly (direct desulfurization) or via H-assisted reactions (hydrogenation). Due to a sizable activation barrier required for the first Csingle bondS bond scission of 54.6 kcal/mol, we predict that the direct desulfurization to contribute rather very insignificantly in the HDS mechanism. Transfer of adsorbed hydrogen atoms on the γ-Mo2N surface to the thiophene ring substantially reduces activation barrier required in the Csingle bondS bond scission to only 24.1 kcal/mol in a process that affords an adsorbed C4H6* species and an S atom. Further hydrogenation of the unsaturated C4H6* produces 2-butene. Kinetics and thermodynamics attributes dictate the occurrence of partial rather than full hydrogenation of C4H6*. Calculated rate constants for all individual steps could be utilized to construct a robust kinetic model for the overall HDS process. Estimated conversion values of thiophene predict 50–70% consumption of thiophene at 700 K and low values of gas hourly space velocities. Reaction routes and kinetic parameters provided herein are useful to design stand-alone γ-Mo2N-based catalysts for applications entailing partial hydrogenation and hydrodesulfurization of severely contaminated S-fuels.
New, easy, simple, and fast spectral method for estimation of sulfamethoxazole (SMZ) in pure and pharmaceutical forms. The proposed method is based on the azotization of the drug compound by sodium nitrite in an acidic medium and then coupling with 2,3dimethyl phenol reagent (DMP) in a basic medium to yield an orange-coloured dye which shows λmax at 402 nm. Different affection of the optimization reaction has been completed, following the classical univariate sequence. The concentration of sulfamethoxazole about (1-15) μg. mL-1 with molar absorptivity of (14943.461) L.mol1 .cm-1 that obeyed Beer’s law. The detection and quantification limits were (0.852, 2.583) μg. mL-1 respectively, while the value of Sandell’s sensitivity (
... Show MoreFrom 144 specimens of tonsillitis which were collected from patient, (children of 3 -12 year olds) there were 70 isolates beta hemolytic and 28 isolates were identified as S. pyogenes. Sensitivity of S. pyogenes isolates to antibiotics was tested, all isolates were sensitive to amoxicillin and cephaloxia while higher resistant were to erythromycin. One isolate whiche was 100 A had a stable characteristics and produce pyrogenic toxin was chosen for study and it was purified and characterized from the cell free supernatant of S. pyrogenes strain.
The toxic lead additives to gasoline are no longer used in many countries around the world. Many other countries are now phasing out the lead in gasoline. Although the lead fuel is still in use in Iraq, several plans are considered to phase out the lead. The use of organic compounds to replace the lead additives in gasoline is considered now as an option in Iraqi refineries. The main objective of this project was preparation of premium gasoline, by blending of gasoline with Alternative additives (alcohol, aromatic) to enhancing octane number of Al-Doura gasoline pool. Improved gasoline was tested by ASTM standard method which includes octane number measuring by CFR engine analyzer. Gasoline pool RON (80) was used and selective components
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Dora petroleum refinery waste water is the one of the important source of pollution by priority pollutant aromatic compound discharged to Tigris river in Iraq. the station has waste water treatment unit contains many treatment subunits The most important sub units is :skimmer units ,physiochemical unit ,daf unit, biological unit. The aim of research project is to study the ability of unit to remove the priority pollutant aromatic compound and follow up these compounds in river to study ability of river to self removal. A solid phase extraction (SPE) followed by high performance liquid chromatography-ultra violet (HPLC-UV) technique is depicted for the quantitative estimation of benzidines and phenols. Experimental studies were performed to
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Simple, sensitive and economical spectrophotometric methods have been developed for the determination of cefixime in pure form. This method is based on the reaction of cefixime as n-electron donor with chloranil to give highly colored complex in ethanol which is absorb maximally at 550 nm. Beer's law is obeyed in the concentration ranges 5-250 µg ml-1 with high apparent molar absorptivities of 1.52×103 L.mole-1. cm-1.
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The research, entitled: "The Development Theory of Women's Empowerment in Islamic Sharia Law ", aims to show the means of human development for women through the texts of the Quran and Sunnah. It talked about the concept of human development for women, the goals of women's empowerment in legislative texts, the goals of human development in empowering women, the developmental aspect of women in the Sunnah of the Prophet, the integration of development in Islamic Sharia Law , and then the conclusion and sources.
Dox, is still widely used in modern cancer treatments for different type of malignancy despite the advent of targeted therapy. However, its beneficial effect was limited by its toxicity on various organs. The objective of this study was to investigate the hepatoprotective effect of menaquinone-7 against hepatotoxicity induced by doxorubicin in rats. Sixty adult rats of both sexes were used in this study; the animals were randomly enrolled into six groups of 10 animals each. Group I: negative control; Group II: Menaquinones-7 at a dose of 16µg/kg; Group III: Menaquinones-7 at a dose of 48µg/kg; Group IV: positive control (Doxorubicin 15mg/kg); Group V: Menaquinones-7 at a dose of 16µg/kg administered prior to a single dose of Doxorubicin
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Regret is a feeling that affects a person when he does something, realizing that his present situation would be better if he did not commit this act, or behaved differently in the past. It is also a look back. It makes a person feel dissatisfied, and hopes if he can change In the past, this research deals with the remorse of the hair of Dick Homs al-Jinn, who killed his sweetheart and his wife (Ward), after an alleged treason without being confirmed, and when he found out the truth he regretted killing her all his life. His poetry is studied carefully, and he has not received the attention of scholars like other poets of his time; and his unwillingness to keep up with
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