Evaluation of Anion Effect on the Solubility of Hydrogen Sulfide in Ionic Liquids Using Molecular Dynamics Simulation

Theoretical Foundations of Chemical Engineering - In this study the solubility of Hydrogen Sulfide (H2S) in four ionic liquids: 1-Ethyl-3-methylimidazoliom Hexafluorophosphate [Emim][PF6],...     

Phase behaviour modelling of Athabasca bitumen for in situ combustion applications

Phase behaviour modelling of reservoir fluid is a fundamental step for reservoir simulation. Furthermore, as the complexity of the recovery process increases, the fluid model plays a more important role in the reliability of the simulation outputs. Although the in situ combustion enhanced oil recovery method (ISC) is one of the most complex recovery techniques available in the petroleum engineering literature, for most of the simulation jobs related to this elaborate process only simple and rudimentary fluid characterization layouts are considered. In this work, the principal fluid properties of Athabasca bitumen with regard to the ISC process are recognized, extracted from the literature, validated for consistency, and used for the development of an inclusive and accurate fluid model. Then the fluid model is fully developed while considering the ISC reaction kinetics so that the model has both accuracy, indispensable for phase behaviour modelling, and consistency, essential for the reactions definitions.     

Genetic Deficiency and Pharmacological Stabilization of Mast Cells Ameliorate Pressure Overload-Induced Maladaptive Right Ventricular Remodeling in Mice

Although the response of the right ventricle (RV) to the increased afterload is an important determinant of the patient outcome, very little is known about the underlying mechanisms. Mast cells have been implicated in the pathogenesis of left ventricular maladaptive remodeling and failure. However, the role of mast cells in RV remodeling remains unexplored. We subjected mast cell-deficient WBB6F1-KitW/W-v (Kit^W/Kit^W-v) mice and their mast cell-sufficient littermate controls (MC^+/+) to pulmonary artery banding (PAB). PAB led to RV dilatation, extensive myocardial fibrosis, and RV dysfunction in MC^+/+ mice. In PAB Kit^W/Kit^W-v mice, RV remodeling was characterized by minimal RV chamber dilatation and preserved RV function. We further administered to C57Bl/6J mice either placebo or cromolyn treatment starting from day 1 or 7 days after PAB surgery to test whether mast cells stabilizing drugs can prevent or reverse maladaptive RV remodeling. Both preventive and therapeutic cromolyn applications significantly attenuated RV dilatation and improved RV function. Our study establishes a previously undescribed role of mast cells in pressure overload-induced adverse RV remodeling. Mast cells may thus represent an interesting target for the development of a new therapeutic approach directed specifically at the heart.     

Sustainability in highrise building design and construction

This paper presents a review of the recent literature on sustainability in construction and design with a focus on highrise buildings. The paper is divided into the following main sections: energy consumption, environmental effects and green practices for highrise buildings. A number of concepts in sustainable design are reviewed including passive solar design, renewable energy resources, cogeneration and tri‐generations, embodied energy reduction, net zero energy building, carbon emission reduction, envelope environment quality, green materials, efficient mechanical design and innovative structural systems. Their applications in a dozen signature and iconic structures are described. In order to achieve net zero energy in a new highrise building, first, multiple green solutions need to be evaluated using two categorical solutions: passive solar and envelop environment design and renewable energy resources along with efficient energy generators. Next, a robust optimization algorithm should be used to select the optimum set of solutions. This is worth pursuing in future sustainable design of highrise buildings because they are massive and complex structures with many components. Copyright © 2016 John Wiley & Sons, Ltd.     

Iterative step‐by‐step procedure for optimal placement and design of viscoelastic dampers to improve damping ratio

In this study, an iterative step‐by‐step procedure is proposed for optimal placement and design of viscoelastic dampers in order to achieve a target damping ratio based on simple equations and quick estimation. Through the procedure, the dampers are placed one by one in stories with maximum interstory drift at each sequence. Effect of lateral stiffness of added dampers and consequent changes in frequency of the structure as well as changes in damping characteristic of the structure after adding each damper are also considered at each sequence. In order to achieve an economical design, dampers are designed according to the lateral stiffness at each story of the main structure instead of using identical dampers in all stories. During the whole procedure, a time‐history analysis is performed at each sequence. Two numerical examples, including an 8‐story and a 15‐story building, are presented. The results indicate that optimal arrangement of dampers has a considerable influence on reduction of roof displacement up to 25% compared to uniformly distributed arrangement of dampers. In addition, with optimal arrangement, the number of dampers needed to achieve a specific interstory drift is significantly reduced, and the structural damping ratio is improved to a target value, reflecting global optimality of the proposed method.     

Solvent screening for non‐aqueous extraction of Alberta oil sands

Non‐aqueous extraction of bitumen from oil sands has the potential to reduce fresh water demand of the extraction process and eliminate tailings ponds. In this study, different light hydrocarbon solvents, including aromatics, cycloalkanes, biologically derived solvents and mixtures of solvents were compared for extraction of bitumen from Alberta oil sands at room temperature and ambient pressure. The solvents are compared based on bitumen recovery, the amount of residual solvent in the extracted oil sands tailings and the content of fine solids in the extracted bitumen. The extraction experiments were carried out in a multistage process with agitation in rotary mixers and vibration sieving. The oil sands tailings were dried under ambient conditions, and their residual solvent contents were measured by a purge and trap system followed by gas chromatography. The elemental compositions of the extraction tailings were measured to calculate bitumen recovery. Supernatants from the extraction tests were centrifuged to separate and measure the contents of fine solid particles. Except for limonene and isoprene, the tested solvents showed good bitumen recoveries of around 95%. The solvent drying rates and residual solvent contents in the extracted oil sands tailings correlated to solvent vapour pressure. The contents of fine solids in the extracted bitumen (supernatant) were below 2.9% for all solvents except n‐heptane‐rich ones. Based on these findings, cyclohexane is the best candidate solvent for bitumen extraction, with 94.4% bitumen recovery, 5 mg of residual solvent per kilogram of extraction tailings and 1.4 wt% fine solids in the recovered bitumen. © 2012 Canadian Society for Chemical Engineering     

An improved mechanism for capacity payment based on system dynamics modeling for investment planning in competitive electricity environment

Many countries have experienced restructuring in their electric utilities. This restructuring has presented the power industries with new challenges, the most important of which is long-term investment planning under uncertain conditions. This paper presents an improved mechanism for capacity payment. The mechanism has been investigated based on system dynamic modeling. In our proposed mechanism, generators will recover a part of their investment through capacity payment. While the payment for any plant remains constant during the operation period, it depends on the investment needed to build it. The main factors affecting long-term planning have been considered in our model. The approach can be used to investigate the effects of fixed as well as variable capacity payment in market investment. We used the probability density function of load as a new concept to calculate average market price. Delays in unit constructions, estimation of demand, and market capacity growth during construction periods have been included in the proposed algorithm as parameters, which affect the regulator's decision for changing capacity payment. The model can be used by regulators to investigate strategies that may affect the fluctuations in the market.     

Synthesis and thermal stability of polystyrene and poly(vinyl chloride) coated with polythiophene and modified with Fe2O3 nanoparticles

In this study, polystyrene and poly(vinyl chloride) particles were coated successfully with polythiophene in aqueous media. These nanocomposites were prepared in situ by polymerization of thiophene in the presence of FeCl₃ as an oxidant and poly(vinyl pyrrolidone) as a surfactant. The effect of Fe₂O₃ nanoparticles on the characteristics of products such as thermal stability and morphology was investigated. The chemical structure, morphology, and thermal stability of these core‐shell nanocomposites were studied by Fourier‐transform infrared spectroscopy, scanning electron microscopy, X‐ray diffraction, and thermogravimetric analysis. Thermal stability of the nanocomposites was compared and indicated that the thermal stability of polythiophene/polystyrene was better than the polythiophene/poly(vinyl chloride) nanocomposite. Also, the presence of Fe₂O₃ nanoparticles can drastically increase the thermal stability of polythiophene nanocomposites. J. VINYL ADDIT. TECHNOL. 20:212–217, 2014. © 2014 Society of Plastics Engineers     

Designing a nuclear battery based on the Mo-99 radioactive source soluble in water and aqua regia in order to use in early tests

Today, millions of electrocommunication, electric, medical, and industrial devices use battery. Batteries with long life and high energy density seem to be essential in medical, military, oil and mining, aerospace areas as well as conditions in which access is difficult and in situations where replacement or recharging of battery is costly.In this regard, the use of radiation energy resulting from radioactive materials and its conversion to electric energy can be effective in making batteries. In the present study,various Mo-99 radioisotope values with a half-life of 65.98 h were used as a soluble radioactive source in two materials of water and aqua regia. Then, by comparing the results of the Monte Carlo simulations program MCNPX for these two solutions, it was found that when the water is used instead of aqua regia(for idealization), the values of the superficial current of electrons, the volumetric flux of electrons, and the deposited energy in the volume containing the radioactive solution increased by 10.80, 4.10,and 13.80%, respectively. Also, the short-circuit current and energy conversion efficiency of this battery with a concentration of 0.01 molar, Mo-99 dissolved in the aqua regia are 0.79μA and 16.47%, respectively.