In situ incorporation of nickel nanoparticles into the mesopores of MCM-41 by manipulation of solvent-solute interaction and its activity toward adsorptive desulfurization of gas oil

In this contribution, different amounts of nickel were incorporated into the mesopores of MCM-41 via an in situ approach. A hydrophobic nickel precursor was incorporated into the nanochannels of mesoporous silica by manipulation of solvent-solute interaction. The synthesized material was characterized using X-ray diffraction, nitrogen physisorption, temperature programmed reduction, and transmission electron microscopy. The results implicate the formation of MCM-41 with well-ordered hexagonal structure and establish also the presence of nickel nanoparticles inside the nanochannels of mesoporous silica. Adsorptive desulfurization of gas oil was conducted using the nickel-incorporated MCM-41 samples. The effects of nickel concentration, temperature of process and feed flow rate on the desulfurization process were examined. The MCM-41 containing 6 wt.% of nickel had both the highest breakthrough sulfur adsorption capacity and total sulfur adsorption capacity, which were 0.69 and 1.67 mg sulfur/g adsorbent, respectively. The breakthrough sulfur adsorption capacity was almost regained after reductive regeneration of spent adsorbent. The obtained results suggest that the method applied for the synthesis of Niy/MCM resulted in formation of well-dispersed, accessible and small nickel nanoparticles incorporated into the pores of MCM-41 which might be an advantage for adsorption of refractory sulfur compounds from low sulfur gas oil.     

Evaluation of ship’s green degree using a novel hybrid approach combining group fuzzy entropy and cloud technique for the order of preference by similarity to the ideal solution theory

Clean Technologies and Environmental Policy - The pollution and emission caused by the manufacturing, operation, and scrapping of marine ships have considerable impact on the environment....     

Improved efficiency of organic/inorganic photovoltaic devices by electrospun ZnO nanofibers

The efficiency of the photovoltaic (PV) device based on P3HT and PCBM bulk heterojunction is improved by introducing small-diameter electrospun ZnO diffused nanofibers network. Diameter, diffusion and melting of nanofibers are controlled by calcination temperature. The thickness of the active layer is optimized for efficient PV devices by varying electrospinning (ES) time. Increased nanofiber's mat thickness by an increase in electrospinning time beyond a certain optimum value reduces the device performance due to increased series resistance, increased traps and reduced blend infiltration through the nanofiber pores. ES time suggests optimized active area for energy absorption and exciton dissociation. In this study, we report the improvement in power conversion efficiency (PCE) from 0.9% to 2.23%, for optimum ES time (∼300 s).     

QoS-aware service composition in cloud computing using data mining techniques and genetic algorithm

One of the requirements of QoS-aware service composition in cloud computing environment is that it should be executed on-the-fly. It requires a trade-off between optimality and the execution speed of service composition. In line with this purpose, many researchers used combinatorial methods in previous works to achieve optimality within the shortest possible time. However, due to the ever-increasing number of services which leads to the enlargement of the search space of the problem, previous methods do not have adequate efficiency in composing the required services within reasonable time. In this paper, genetic algorithm was used to achieve global optimization with regard to service level agreement. Moreover, service clustering was used for reducing the search space of the problem, and association rules were used for a composite service based on their histories to enhance service composition efficiency. The conducted experiments acknowledged the higher efficiency of the proposed method in comparison with similar related works.     

Fracture toughness prediction using Weibull statistical method for asphalt mixtures containing different air void contents

Brittle fracture of asphalt mixtures at low temperatures is one of the main deterioration modes of pavements. Hence as an important design parameter, it is required that a reliable value for fracture toughness of asphalt mixtures is known. However, because of natural inhomogeneity of asphalt mixtures and inherent sources of scatters such as random distribution of ingredients and preparation process, the use of statistical analyses might provide better estimations for the crack growth resistance of asphalt mixtures. In this paper by conducting several low temperature fracture toughness experiments on three types of asphalt mixtures with different air void contents, the effects of air void percentage on mode I fracture toughness are studied statistically. Fifty six edge cracked semi-circular bend specimens containing 4, 5 and 7% air voids were tested, and the corresponding two and three-Weibull distribution parameters were determined for each set of data. It was shown that the Weibull model can be used successfully for predicting the statistical nature of tensile cracking phenomenon in asphalt mixtures. The mean fracture toughness values and the Weibull parameters were reduced by increasing the air void content. Furthermore, the distribution parameters obtained experimentally for the mixtures containing 4% and 5% voids were also predicted quite well in terms of the Weibull parameters of a reference mixture containing 7% air void.     

Ring-Sheared Drop (RSD): Microgravity Module for Containerless Flow Studies

Microgravity is potentially a powerful tool for investigating processes that are sensitive to the presence of solid walls, since fluid containment can be achieved by surface tension. One such process is the transformation of protein in solution into amyloid fibrils; these are protein aggregates associated with neurodegenerative diseases such as Alzheimer’s and Parkinson’s. In addition to solid walls, experiments with gravity are also subject to influences from sedimentation of aggregates and buoyancy-driven convection. The ring-sheared drop (RSD) module is a flow apparatus currently under development to study formation of amyloid fibrils aboard the International Space Station (ISS). A 25 mm diameter drop of protein solution will be contained by surface tension and constrained by a pair of sharp-edged tubes, forming two contact rings. Shear can be imparted by rotating one ring with the other ring kept stationary. Here we report on parabolic flights conducted to test the growth and pinning of 10 mm diameter drops of water in under 10 s of microgravity. Finite element method (FEM) based fluid dynamics computations using a commercial package (COMSOL) assisted in the design of the parabolic flight experiments. Prior to the parabolic flights, the code was validated against experiments in the lab (1 g), on the growth of sessile and pendant droplets. The simulations show good agreement with the experiments. This modeling capability will enable the development of the RSD at the 25 mm scale for the ISS.     

Protection by extracellular glutathione against sulfur mustard induced toxicity in vitro

BACKGROUND: Salmeterol xinafoate is a highly selective beta2-adrenoceptor for the maintenance treatment of asthma in adults and children. OBJECTIVE: To review the pharmacokinetics, clinical pharmacology, and therapeutic properties of a recently introduced, long acting antiasthmatic drug. METHODS: Recent English-language publications were selected using Medline as database. RESULTS: Salmeterol's pharmacokinetics, clinical pharmacology, and therapeutic properties are reviewed and aspects related to salmeterol's unusual duration of action, its high potency, beta2-selectivity, possible antiinflammatory actions, its interaction with other drugs, low systemic adverse effects, dosage, and administration are also discussed. CONCLUSION: Salmeterol is a safe long-acting beta2-agonist very useful for maintenance treatment of asthma.     

Robust control of connected vehicles via V2V communication

This paper introduces a robust controller for connected vehicles which are communicating through dedicated short‐range communication (DSRC) protocol to avoid collision and improve safety. By a comprehensive analysis on both longitudinal and lateral dynamics of the vehicles, the controller covers a wide range of collision avoidance scenarios, such as: Intersection Movement Assistant (IMA), Automatic Emergency Brake (AEB) and Lane Change Warning (LCW). By implementing an advanced Sliding Mode Controller (SMC), the effect of uncertainties will be mitigated for a variety of path plans. It turns out that the proposed control scheme can robustly improve the safety. Finally, we optimize the performance of vehicles in tracking the paths by an MPC controller.     

FOM – a MATLAB toolbox of first-order methods for solving convex optimization problems

This paper presents the FOM MATLAB toolbox for solving convex optimization problems using first-order methods. The diverse features of the eight solvers included in the package are illustrated through a collection of examples of different nature.