The present study reports a highly selective and stable catalytic approach for producing tetralin, an important chemical, solvent, and H2 storage material. Transition metal phosphides (MOP, Ni2P, Co2P, and Fe2P) wer...
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The present study reports a highly selective and stable catalytic approach for producing tetralin, an important chemical, solvent, and H2 storage material. Transition metal phosphides (MOP, Ni2P, Co2P, and Fe2P) were prepared by wet impregnation and temperature-programmed reduction and characterized by X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), EDX mapping, scanning electron microscopy (SEM), transmission electron microscopy (TEM), brunauer-emmett- teller (BET), temperature-programmed desorption of ammonia (NH3-TPD), and fourier transform infrared spectroscopy of pyridine (pyridine-FTIR). Of all the transition metal phosphides MoP was formed at a lower reduction temperature, which resuited in smaller particle size that enhanced the overall surface area of the catalyst. The existence of weak, moderate, and Lewis acidic sites over MoP were responsible for its high tetralin selectivity (90%) and stability during the 100 h reaction on-stream in a fixed-bed reactor.
A systematic approach for the steady-state operation analysis of chemical processes is *** method affords the possibility of taking operation resilience into consideration during thestage of process *** may serve the ...
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A systematic approach for the steady-state operation analysis of chemical processes is *** method affords the possibility of taking operation resilience into consideration during thestage of process *** may serve the designer as an efficient means for the initial screening ofalternative design *** ideal heat integrated distillation column(HIDiC),without any reboileror condenser attached,is studied throughout this *** has been found that among the various va-riables concerned with the ideal HIDiC,feed thermal condition appears to be the only factor exertingsignificant influences on the interaction between the top and the bottom control *** is expected when the feed thermal condition approaches *** number of stages andheat transfer rate are essential to the system ability of disturbance ***,more stagesand higher heat transfer rate ought to be ***,too many stages and higher heat transfer ratemay increase the load of the
This article outlines the use of artificial intelligence in three areas of biotechnology: (a) exploration of new production routes for various bioproducts; (b) design of mammalian cell biofermentors; and (c) synthesis...
This article outlines the use of artificial intelligence in three areas of biotechnology: (a) exploration of new production routes for various bioproducts; (b) design of mammalian cell biofermentors; and (c) synthesis of downstream processing schemes for the separation and purification of proteins. Until recently, all of these areas have been ‘knowledge intensive’, driven by the incisive expertise of scientists and engineers, and quite resistant to analytic and rigorous mathematical formulations and solutions. Here we describe the ‘prototype intelligent system’ used in the above three areas, and attempt simple projections on the use of artificial intelligence in biotechnology.
This work describes the hydrothermal synthesis and characterization of zeolite 4A (Zeo-4A) and magnetite zeolite (Zeo-4A@Fe3O4) from Cameroonian raw kaolin. The study also explores the efficiency of Zeo-4A@Fe3O4 for t...
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This work describes the hydrothermal synthesis and characterization of zeolite 4A (Zeo-4A) and magnetite zeolite (Zeo-4A@Fe3O4) from Cameroonian raw kaolin. The study also explores the efficiency of Zeo-4A@Fe3O4 for the removal of quinoline yellow (E104) via Fenton process. XRD, FTIR, SEM, EDX, NMR-MAS and TGA-DSC characterizations show that Zeo-4A is crystalline with cubic morphology, while Zeo-4A@Fe3O4 exhibits a bonding interaction between zeolite and Fe3O4 nanoparticle leading to morphological structural changes. The degradation of quinoline yellow by heterogeneous Fenton process was carried out by varying several parameters, namely solution pH (3–7), H2O2 concentration (0.5–1.5 mol/L), quinoline yellow concentration (50–100 mg/L), and catalyst mass (50–100 mg). The results of catalytic performance tests reveal that the degradation efficiency of synthetic Zeo-4A, Zeo-4A@Fe3O4 and Fe3O4 were 1.71 %, 93.60 % and 92.65 %, respectively, after 60 min. Confirmatory tests were carried out by response surface methodology based on the Box-Behnken design, and a degradation rate of 98.81 % was obtained under optimum conditions of pH 3.84, 50.14 mg/L, 100 mg, and 1.5 g/L;which is well in line with the model predictions. A significant quadratic regression model R2 = 91.35 % and the adjusted coefficient of determination value (adjusted R2 = 82.04 %) were observed using the analysis of the variance. The study of catalyst recovery and reusability shows that the catalysts remain stable with a degradation rate greater than 66 % after five cycles. The kinetics results show that the degradation of E104 follows first and second order kinetic models, influenced by pH and catalyst mass, with optimum efficiency at pH 3. The characterization results of the material after degradation show that it maintains its stru
Two innovative methods, the different core couple (DC) method and the tapered corrosion (T-C) method, are proposed to improve traditional fiber bundle corrosion techniques for fabricating fan-in/fan-out (FI/FO) device...
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We study, in this paper, the feasibility of using preconditioned iterative methods to solve linear systems on MIMD (multiple instruction multiple data) machines when solving steady-state simulation problems. We show t...
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We study, in this paper, the feasibility of using preconditioned iterative methods to solve linear systems on MIMD (multiple instruction multiple data) machines when solving steady-state simulation problems. We show that, provided a good parallel preconditioner is available, the proposals in this paper give very good parallel performance. Our proposals are directly applicable to almost block diagonal linear systems, but can be extended to more general flowsheeting problems (Paloschi, 1996). This will be the subject of a future paper. A preconditioning strategy blending an incomplete LU decomposition with a polynomial preconditioner is proposed and tested with the iterative method GMRES of Saad and Schultz (1986). A parallel implementation is tested on two MIMD machines, a Fujitsu AP1000 with 128 processors and a cluster of workstations with PVM (Parallel Virtual Machine) (Geist et al., 1994). Two examples are used, a simple model of a distillation column using Antoine coefficients and the discretization of a PDE. The second example allows the variation in the size of the problem and results are presented for up to 65 536 equations on the AP1000 and 262 144 equations on the cluster. Almost perfect efficiency is observed when solving a problem of size 65 536 using 32 processors on the AP1000 (and size 16 384 using 16). Very good speed-ups also are obtained on the cluster Df workstations (a speed-up of 15.3 using 16 processors) when solving a problem of size 65 536. The results on the cluster are presented for different load conditions on the network. (C) 1997 Elsevier Science Ltd.
Based on the quantum chemical descriptors and the activities for isoprene polymerization of 12 neodymium carboxylates obtained by authors’earlier work,statistical analysis of data was made and a QSAR model correlatin...
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Based on the quantum chemical descriptors and the activities for isoprene polymerization of 12 neodymium carboxylates obtained by authors’earlier work,statistical analysis of data was made and a QSAR model correlating the quantum chemical descriptors and the activity was built with the partial least square(PLS)*** model is:A=51602εHOMO+6σ+12546,which indicates that the catalytic activity A is positively correlated with the HOMO energyεHOMOand the ligand polarizabilityσ,with the contribution ofσbeing larger,εHOMO *** model’s coefficient of determination r^2=0.96 and that of cross validation q^2=0.94,both being close to 1,which means that its quality is well and its predictive power is *** of the modeling process and the resulted QSAR model,together with the interpretation of the model’s mechanism,also shows that the model obtained from this study is valid and *** to the QSAR model,the mechanism of catalyst activity can be interpreted as that neodymium carboxylates with higher HOMO energy and larger ligand polarizability are easier to react with the co-catalysts so as to produce more active and stable centers of catalyst,resulting in a higher activity.
The inorganic sorbent potassium cobalt(II) hexacyanoferrate(II) was tested for removal of radiocesium from alkaline salt solutions that are typical of intermediate level radioactive wastes generated at spent fuel repr...
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The inorganic sorbent potassium cobalt(II) hexacyanoferrate(II) was tested for removal of radiocesium from alkaline salt solutions that are typical of intermediate level radioactive wastes generated at spent fuel reprocessing plants in India. Excellent results were obtained both in batch equilibration and column operation.
Optimized exothermic semi-batch emulsion polymerization typically exhibits active arcs of the constraints for the reactor temperature. Given parametric uncertainties in the process model, this might lead to constraint...
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Photocatalytic ozonation of phenol and oxalic acid (OA) was conducted with a Ag^+/TiO2 catalyst and different pathways were found for the degradation of different compounds. Ag^+ greatly promoted the photocatalyti...
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Photocatalytic ozonation of phenol and oxalic acid (OA) was conducted with a Ag^+/TiO2 catalyst and different pathways were found for the degradation of different compounds. Ag^+ greatly promoted the photocatalytic degradation of contaminants due to its role as an electron scavenger. It also accelerated the removal rate of OA in ozonation and the simultaneous process for its complex reaction with oxalate. Phenol could be degraded both in direct ozonation and photolysis, but the TOC removal rates were much higher in the simultaneous processes due to the oxidation of hydroxyl radicals resulting from synergetic effects. The sequence of photo-illumination and ozone exposure in the combined process showed quite different effects in phenol degradation and TOC removal. The synergetic effects in different combined processes were found to be highly related to the properties of the target pollutants. The color change of the solution and TEM result confirmed that Ag+ was easily reduced and deposited on the surface of Tit2 under photo-illumination, and dissolved again into solution in the presence of ozone. This simple cycle of enrichment and distribution of Ag^+ can greatly benefit the design of advanced oxidation processes, in which the sequences of ozone and photo-illumination can be varied according to the needs for catalyst recycling and the different properties of pollutants.
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