Papers by Mohammad F Abid
Bulletin of Chemical Reaction Engineering & Catalysis
A homemade N doped-TiO2 nanoparticle were used to degrade dibenzothiophene (DBT) in a model fuel ... more A homemade N doped-TiO2 nanoparticle were used to degrade dibenzothiophene (DBT) in a model fuel flowing on a bench-scale glass-made falling film reactor irradiated by a xenon lamp that emitted visible light. The photocatalyst was immobilized on the glass sheet. EDS, SEM, and FT-IR techniques were utilized to identify the morphology of the N doped-TiO2 nanoparticles. Different operating parameters (e.g., N loading (0, 4, 5, and 6 wt%), light intensity (20, 40, and 60 W/m2), and pH (4, 7, and 10)) were investigated for their effect on the DBT degradation. The effect of the N loading on the wettability of the nano-TiO2 particles was also investigated. Experimental results revealed that the N loading did not affect the wettability characteristics of the nano TiO2 particles. Moreover, results showed that DBT conversion positively depends on N loading, light intensity (hv), and pH increase. The estimated optimal operating parameters were 5 wt% N loading, pH = 10, and hv = 40 W/m2 to ens...
DESALINATION AND WATER TREATMENT, 2018
Antibiotics
Methionine aminopeptidases (MetAPs) are attractive drug targets due to their essential role in eu... more Methionine aminopeptidases (MetAPs) are attractive drug targets due to their essential role in eukaryotes as well as prokaryotic cells. In this study, biochemical assays were performed on newly synthesized Isatin-pyrazole hydrazones (PS1–14) to identify potent and selective bacterial MetAPs inhibitors. Compound PS9 inhibited prokaryotic MetAPs, i.e., MtMetAP1c, EfMetAP1a and SpMetAP1a with Ki values of 0.31, 6.93 and 0.37 µM, respectively. Interestingly, PS9 inhibited the human analogue HsMetAP1b with Ki (631.7 µM) about ten thousand-fold higher than the bacterial MetAPs. The in vitro screening against Gram-positive (Enterococcus faecalis, Bacillus subtilis and Staphylococcus aureus) and Gram-negative (Pseudomonas aeruginosa, Klebsiella pneumonia and Escherichia coli) bacterial strains also exhibited their antibacterial potential supported by minimum bactericidal concentration (MBC), disk diffusion assay, growth curve and time-kill curve experiments. Additionally, PS6 and PS9 had sy...
Tikrit Journal of Engineering Sciences
An industrial scale falling film reactor (FFR) using gaseous SO3/ liquid Alkylbenzene as operatin... more An industrial scale falling film reactor (FFR) using gaseous SO3/ liquid Alkylbenzene as operating system- is analyzed for multiplicity and stability. The analysis has shown that up to 5 steady state solutions may exist. The existence of a highly multiplicity states is explained by the coupling between absorption and reaction. The system kinetic parameters have found to play an effective role on the stability behavior. An analytic solution is found for a special case of the liquid reactant in excess, this solution is performed by using eigen analysis. A mathematical procedure is also introduced to estimate the bifurcation points.
Al-Nahrain Journal for Engineering Sciences, 2011
A mathematical model for a slurry bioreactor was proposed to describe oxygen utilization rate and... more A mathematical model for a slurry bioreactor was proposed to describe oxygen utilization rate and concentration profiles along the reactor for reactants and products in the bubbly flow regime. The model consisted of transient differential equations representing mass transfer and kinetics of oxygen, biomass and substrates in the liquid phase. The model was validated by comparing with experimental work of other authors and a good agreement was obtained, theabsolute average error between model and experimental results was 4.3%. The effects of various operating parameters on the concentration profile of oxygen and biomasswere investigated theoretically. The dissolved oxygen concentration was significantly affected by the superficial liquid velocity than that bysuperficial gas velocity. Unsteady state concentration profile of oxygen showed different behaviors gas and liquid.
Global Journal of Research In Engineering, 2017
Arabian Journal for Science and Engineering, 2017
The present work was devoted to investigate the kinetic behavior of an industrial-scale ebullated... more The present work was devoted to investigate the kinetic behavior of an industrial-scale ebullated bed reactor, licensed by Axens Co., in Lukoil refinery at Bourgas, Bulgaria. Another objective of the present work is to formulate a steady state mathematical model to predict the profile of products along the reactor, and to investigate effects of the operating variables [e.g., operating temperature, weight hour space velocity (WHSV), and reaction time] on the kinetic parameters, and performance of the industrial ebullated bed reactor. A five-lump kinetic model was utilized to describe the catalytic hydrocracking of heavy oil and to formulate the reaction rate equations of the main components of heavy oil. The formulated model was validated by comparing its outcome with experimental measurements of fractions of VR, VGO, and N at the effluent of industrial reactor against residence time. Results revealed an opposite relationship of the effectiveness factor with both temperature and WHSV. Results showed that the activation and deactivation energies were approximately equal, indicating that catalyst deactivation has no appreciable effect on the hydrocracking reactions in the ebullated bed reactor. The hydrocracking reactions of B Mohammad F.
Journal of King Saud University - Engineering Sciences, 2017
This study aimed to investigate the hydrodesulfurization (HDS) of a mixture of crude oil fraction... more This study aimed to investigate the hydrodesulfurization (HDS) of a mixture of crude oil fractions (e.g., naphtha, kerosene, and gas oil) all in one time in a single reactor under various operating parameters such as temperature (T = 310-370°C), pressure (P = 40-55 bar), weight hour space velocity (WHSV = 1.2-3.6 h À1) , hydrogen-to-hydrocarbon ratio (150-300 vol/vol), and type of catalysts (di-metallic and trimetallic). Experimental results showed that temperature and pressure have positive effects on process performance while weight hour space velocity gives a different trend. Results indicated that HDS efficiency was 95.8% at optimized operating parameters T = 350°C, P = 50 bars, WHSV = 1.2 h À1 , and (H 2 /HC) ratio = 200 vol/vol. and with NiCoMo/c-Al 2 O 3 catalyst which offered a higher HDS efficiency compared with other types of catalysts used. Kinetic analysis revealed that a pseudo-first order rate law is well expressing the HDS reaction of the operating system for all types of catalysts. Estimation of rate parameters over each type of catalyst was also presented. Study of mass transfer limitations revealed that surface reaction is the rate controlling step. Feasibility of the proposed technique may offer a large reduction in fixed and operating costs of the HDS unit in a modern petroleum refinery.
RSC Advances, 2018
The present study elicits the synthesis of 1,2,3-triazole–quinazolinone conjugates (5a–q) as ergo... more The present study elicits the synthesis of 1,2,3-triazole–quinazolinone conjugates (5a–q) as ergosterol inhibitors forCandidainfections.
Journal of King Saud University - Engineering Sciences, 2018
This study aimed to investigate the preparation and application of a green chemical (i.e., dimeth... more This study aimed to investigate the preparation and application of a green chemical (i.e., dimethyl carbonate (DMC)) as an anti-knocking agent for gasoline. Another objective was to study the usage of wastes of eggs as a heterogeneous catalyst in the process. Results of Brunauer-Emmett-Teller method showed that both the surface area and pore volume of calcined eggshell and pure CaO were of the same order. Results showed that calcined eggshell and pure CaO have almost the same X-ray diffraction images confirming the suitability of eggshell wastes as a heterogeneous catalyst for the preparation of DMC. SEM analysis revealed that the morphology of the CaO nano-particles are spherical shape for the Nanoparticles (NPs) and CaO was determined to be ~ 63 nm in size. FTIR (Fourier-transform infrared spectroscopy) spectra of reaction mixture proved the presence of dimethyl carbamate in the resulting sample. Experimental results indicated that optimum
Journal of King Saud University - Engineering Sciences, 2017
The present study is devoted to investigate the removal of phenol, which has been selected as a m... more The present study is devoted to investigate the removal of phenol, which has been selected as a model for the toxic organic compounds by using a parabolic trough collector (PTC) photo catalysis system. The solar photo-catalytic system performance was tested in terms of the phenol removal (%R phenol) and TOC mineralization efficiency (%M TOC) by using FeSO 4 as a catalyst and Oxalic acid as a solar photo assisted agent to enhance the process efficiency. Different operating conditions were studied to investigate the performance of the photo-catalysis system, such as initial phenol concentration, initial H 2 O 2 concentration, FeSO 4 /Oxalic weigh ratio, pH of solution, and solution flow rate. The operating variables were optimized to obtain a maximum efficiency for the system performance. Results showed that optimum addition of ferrioxalate complexes (3 mg/L) enhanced the degradation of phenol by (20-30%) at 120 min of illumination time. A quadratic-second-degree polynomial equation was developed for (%R phenol) and (%M TOC) with correlation coefficients (R 2) of 95.26% and 95.2%, respectively.
Arabian Journal for Science and Engineering, 2017
The present work was devoted to study the effect of nitrogen compounds on hydrodesulfurization (H... more The present work was devoted to study the effect of nitrogen compounds on hydrodesulfurization (HDS) activity of straight-run heavy naphtha loaded with thiophene, as a sulfiding model, onto a commercial CoMo/Al 2 O 3 in a fixed bed reactor. Parameter evaluation of ideal flow behavior in the reactor revealed that a catalyst bed packed with a particle diameter = 316 μm helps to eliminate wall, poor wetting and back-mixing effects. Results showed that sulfur removal would be enhanced by increasing temperature, and pressure, while liquid flow rate gives a different trend. The effect of nitrogen compounds on reaction rate constant was investigated (at temperature 320-380 • C, pressure 30 bar, particle diameter 316 μm, and WHSV = 2.5 h −1) with different concentrations of carbazole and pyridine, and a mixture with equal weight proportions of them. The experimental results were fitted to a first-order kinetics with correlation coefficients higher than 0.98. The experimental results confirmed that addition of nitrogen compounds does not affect the order of HDS reaction. Hydrodesulfurization efficiency was decreased from 93.4 to 73.3, 66.5, and 63.3% as the concentration of carbazole, pyridine, and a mixture of them increased from 0 to 100 ppmw, respectively. As observed from experimental results, the inhibiting effect of nitrogen compounds on HDS activity increased as the nitrogen concentration increased. The inhibition behavior was found to be highly nonlinear.
RSC Advances, 2015
Diketo acids and their peptidic analogues were designed and synthesised as bacterial MetAP inhibi... more Diketo acids and their peptidic analogues were designed and synthesised as bacterial MetAP inhibitors. In the enzymatic assay, the representative compound 5e showed excellent inhibition of bacterial MetAPs with no cytotoxicity.
BioMed Research International, 2015
Physiological hemostatic balance is a coordinated outcome of counteracting coagulation and fibrin... more Physiological hemostatic balance is a coordinated outcome of counteracting coagulation and fibrinolytic systems. An imbalance of procoagulant and anticoagulant factors may result in life threatening thromboembolism. Presently, anticoagulant administration is the first line of therapy for the treatment of these conditions and several anticoagulants have been approved, including various forms of heparin. However, the polyanionic nature and multispecificity of heparin pose several complications. Generally, the polysulfated compounds with antithrombotic potential are thought to have feasible synthetic procedures with much less bleeding, thus having favourable safety profiles. Here we report the synthesis of a novel compound, trehalose octasulfate and the assessment of its anticoagulation potential. Molecular docking of trehalose and trehalose octasulfate with antithrombin showed a specificity switch in binding affinity on sulfation, where trehalose octasulfate interacts with critical re...
Proceedings Mathematical Sciences, 1993
In this paper we obtain a generalisation of a theorem of Mohanty and Ray (Can.
International Journal of Pressure Vessels and Piping, 2013
In this study, the effect of different tip angles (30 , 60 , 90 and 120) on the arc and weld pool... more In this study, the effect of different tip angles (30 , 60 , 90 and 120) on the arc and weld pool behavior is analyzed in 2 mm and 5 mm arc lengths with tilted (70) torch. Arc temperature, velocity, current density, heat flux and gas shear are investigated in the arc region and pool convection and puddle shapes are studied in the weld pool region. The arc temperature at the tungsten electrode is found the maximum with sharp tip and decreases as the tip angle increases. The arc temperature on the anode (workpiece) surface becomes concentrated with increase in tip angle. The arc velocity and gas shear stress are observed large with sharp tip and decreasing as the tip angle increases. Current density on the anode surface does not change with tip angle and observed almost the same in all the tip angles in both 2 mm and 5 mm arc lengths. Heat flux due to conduction and convection is observed more sensitive to the tip angle and decreases as the tip angle increases. The electromagnetic force is slightly observed increasing and the buoyancy force is observed slightly decreasing with increase in tip angle. Analyzing each driving force in the weld pool individually shows that the gas drag and Marangoni forces are much stronger than the electromagnetic and buoyancy forces. The weld pool shape is observed wide and shallow in sharp and narrow and deep in large tip angle. Increasing the arc length does not change the weld pool width; however, the weld pool depth significantly changes with arc length and is observed deep in short arc length. The arc properties and weld pool shapes are observed wide ahead of the electrode tip in the weld direction due to 70 torch angle. Good agreement is observed between the numerical and experimental weld pool shapes.
AIP Conference Proceedings
Journal of Petroleum Exploration and Production Technology
Study has shown that the precipitation of asphaltenes could be the most detrimental mechanism tha... more Study has shown that the precipitation of asphaltenes could be the most detrimental mechanism that significantly influences well productivity during crude oil processing. The flow of the crude oil could seriously be affected if the effect of the asphaltenes is not inhibited. This study aims to investigate the effect of TiO2-based nanofluid in stabilizing crude oil flow. The effect of the ratio of TiO2/SiO2 nanocomposite in the organic nanofluid, the salinity of the nanofluid, and pH on the amount of organic solvent (n-heptane) added to stabilize the crude oil flow was investigated using Gaussian Process Progression (GPR) with five kernel functions [exponential square kernel (model 1), rotational quadratic (model 2), Matern 5/2 (model 3), exponential (model 4), and non-isotopic rotational quadratic (model 5)]. The GPR using the various kernel function had good modeling of the relationship between the ratio of TiO2/SiO2 nanocomposite in the organic nanofluid, the salinity of the nanof...
IOP Conference Series: Earth and Environmental Science, 2021
The present work aims to study the degradation of mefenamic acid (MFA) in synthetic wastewater ex... more The present work aims to study the degradation of mefenamic acid (MFA) in synthetic wastewater experimentally and numerically. The experiments were carried out using utilizing homemade Cu doped TiO2 in a solar irradiated falling film reactor. Two operating variables are investigated; pH of the wastewater in the range of (3-10) and synthesis wastewater flow rate (1-3 L/min). The numerical study involves the optimization of the variables. The multifactorial design method, Design of Experiments (DOE), and Response Surface Methodology (RSM) were used to evaluate the interaction effect of the two variables on the degradation of mefenamic acid. The significance of 0the results was evaluated by statistical analysis of variance (ANOVA). The results show that the removal efficiency increasing with increasing pH and decreases with wastewater flow rate. The results have shown that the interaction effects between mentioned factors were highly significant in influencing MFA degradation by analyz...
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Papers by Mohammad F Abid