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.
This study aims to test ceramic waste's capacity to remove nickel from aqueous solutions through adsorption. Ceramic wastes were collected from the Refractories Manufacturing Plant in Ramadi. Through a series of lab tests, the reaction time (5, 10, 15, 20, 25, 30, 35, 40, 45, and 50 minutes, and Ni concentrations (20, 40, 60, and 80) were tested using ceramic wastes with a solid to liquid ratio of 2g/30ml. At a temperature of 30ºC, the pH, total dissolved solids (TDS), and electrical conductivity (EC) were all measured. The equilibrium time was set at 30 min. Thereafter, the sorption (%) somewhat increased positively with the Ni concentration. Freundlich's equation showed that the adsorption intensity is 1.1827 and the Freundlich c
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توصيف الاساليب الارهابية وسبل مواجهتها
United Arab of Emirates made efforts in developing workforce in the field of nuclear energy that it had a chance to attract specialized of this field that it reflect growth in every field of life through which it take special procedures to face casas as fokoshima .the state had started to apply the UAE peaceful nuclear program by opening (Baraka)station in 2010 as to be the first in the Arab world to aim to enhance and diversification energy sources of electricity there in addition to enhance the state’s efforts to achieve economic refreshing and environmental protect.
In this study, measuring effectiveness Alauriz in some seeds powder and found that the seeds of-sophistication sex had the highest effective enzymatic reach 353 units / gProtein and Alkabbatah study enzyme extract under different storage conditions and Altaj showed that the enzyme loses Thbatih and whether Mrkbhetwan adding Alklasrin concentration of 10% for the systematic solution
Purpose: The aim of this study was to gain insight into causes of time delays and cost overruns in a selection of thirty case projects in Iraq. Delay factors have been studied in many countries/contexts, but not much data exists from countries under the conditions characterizing Iraq during the last 10-15 years.Design/methodology/approach: A case study approach was adopted, with thirty construction projects selected from the Baghdad region, of different types and sizes. For the case of the study, the participants in the projects provided data about the projects through the data collection tool distributed through the questionnaire directed to them. Statistical data analysis was used to build statistical relationships between time and cost d
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Discrete Krawtchouk polynomials are widely utilized in different fields for their remarkable characteristics, specifically, the localization property. Discrete orthogonal moments are utilized as a feature descriptor for images and video frames in computer vision applications. In this paper, we present a new method for computing discrete Krawtchouk polynomial coefficients swiftly and efficiently. The presented method proposes a new initial value that does not tend to be zero as the polynomial size increases. In addition, a combination of the existing recurrence relations is presented which are in the n- and x-directions. The utilized recurrence relations are developed to reduce the computational cost. The proposed method computes app
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Astragalus mesogitanus is a new recorded species for Iraqi flora, from Onobrychium genus section, was collected from Erbil district, all morphological features were described in details as well as some micromorphological character as the trichomes and were provided with dimensions and plates, section key was also updated which illustrated the importance of standard (corolla) trichomes in species identification. Keywords: Astragalus, Fabaceae, Iraq, New record, Onobrychium, Trichomes.
The research aims to identify the effect of applying administrative decentralization to an educational performance by assessing educational performance before and after the process of transferring powers from the federal government (the Iraqi Ministry of Education) to local governments (governorates) as well as identifying the appropriate central or decentralized administrative system to advance the educational reality and performance. To achieve the goal of the research, educational data was collected and analyzed, as well as the measurement of educational performance indicators and analysis during two phases, the first represents the stage of applying the central system and spanned between the academic year (2011-2012) and the
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