Lattice Boltzmann method based on Dual-MRT model for three-dimensional natural convection and entropy generation in CuO–water nanofluid filled cuboid enclosure included with discrete active walls

In the present study, the three-dimensional natural convection and entropy generation in a cuboid enclosure included with various discrete active walls is analyzed using lattice Boltzmann method. The enclosure is filled with CuO–water nanofluid. To predict thermo-physical properties, dynamic viscosity and thermal conductivity, of CuO–water nanofluid, the KKL model is applied to consider the effect of Brownian motion on nanofluid properties. In lattice Boltzmann simulation, two different MRT models are used to solve the problem. The D3Q7-MRT model is used to solve the temperature filed, and the D3Q19 is employed to solve the fluid flow of natural convection within the enclosure. The influences of different Rayleigh numbers $\left(10^3<Ra<10^6\right)$ and solid volume fractions $\left(0<\phi <0.04\right)$ and four different arrangements of discrete active walls on the fluid flow, heat transfer, total entropy generation, local heat transfer irreversibility and local fluid friction irreversibility are presented comprehensively.     

Antioxidant Effects of Grape Pomace on the Quality of Silver Carp (Hypophthalmichthys molitrix) Fillets During Refrigerated Storage

This study aimed to determine the phenolic content and antioxidant effect of grape pomace extract on silver carp fillets during refrigerated storage. Total phenolic content of grape pomace extract was quantified by colorimetric methods. Silver carp samples were treated with 0, 2, and 4% of grape pomace extract (g extract/100 g flesh) and stored 15 days in a refrigerator (4°C). Changes in pH, peroxide value, thiobarbituric acid, and heme iron at 0, 3, 6, 9, 12, and 15 days of storage were investigated. Results showed that the values of pH, peroxide value, and thiobarbituric acid increased and iron levels decreased in all treatments during storage (p < 0.05). The phenolic contents were generally much more influenced by the quality parameters treated compared to the control. The addition of grape pomace extract delayed lipid oxidation in silver carp fillet considerably during refrigerated storage. These results suggested that grape pomace extract has the potential to be used as a natural antioxidant.     

Adsorptive removal of petroleum hydrocarbons from aqueous solutions by novel zinc oxide nanoparticles grafted with polymers

Zinc oxide nanoparticles were synthesized and modified by a three-stage method. Elemental analysis, Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning and transmission electron microscopy, and Brunauer–Emmett–Teller method were applied to characterize the nanoparticles. These nanoparticles were evaluated for toluene adsorption from aqueous solutions as a representative of petroleum hydrocarbon removal. The optimum adsorption condition achieved at pH of 6 and contact time of 30 min. The adsorption isotherms were fitted to the Langmuir model. The measured adsorption capacity was 12.8 mg g^?1. This study demonstrated that these nanoparticles could be used as an effective adsorbent for petroleum hydrocarbon removal.     

ECONOMIC DESIGN AND OPTIMIZATION OF ZEOLITE-BASED CUMENE PRODUCTION PLANT

The aim of this work is intensification of an industrial-scale production process of cumene to obtain higher profitability and reduce the energy requirements of the process. In the first step, two topological changes were made in the reactor configuration and benzene separation column, which led to a considerable reduction in utility requirements and equipment sizes in the process. In the second step, parametric optimization was carried out by a statistical method (full factorial design) to adjust the process parameters. In the final step, a pinch analysis was done to reduce utility requirements of the process. A mathematical model was developed based on the statistical analysis, which was then used to obtain optimized conditions of the process. The capital investment of the process remained almost intact, around $4.5 million, and the utility requirements reduced from $2.44 to 1.49 million/yr. These changes greatly enhanced the profitability of the process, for which the net present value was increased from $0.82 to 4.53 million.     

The effect of isopropanol addition on enhancement of transdermal controlled release of ibuprofen from ethylene vinyl acetate copolymer membranes

This work reports the study of the addition of isopropanol on controlled release of ibuprofen from ethylene vinyl acetate (EVAc) copolymer membranes. An EVAc solution in cyclohexane (4% w/v) containing triethyl citrate (7% w/v) as plasticizer was mixed with ibuprofen at three different concentrations of 4, 6, and 8%. Isopropanol was mixed with each of the previous mixtures to form solutions of 1, 3, and 5% isopropanol concentrations. Samples were solvent cast on glass petri‐dishes to form membranes. Home‐made diffusion cells were used for in vitro study. These cells were composed of two compartments, donor (exposed to ambient conditions), and receptor (including buffer solution maintained at 37°C). Each cell was equipped with a sampling port and water in and out system. An ultraviolet spectrometer at 222 nm was used to measure release rates of obtained membranes. The diffusion mechanism for drug release was examined by zero‐order, first‐order, Higuchi and Korsmeyer‐Peppas theories to confirm the obtained membranes follow the matrix‐type system. By increasing the drug concentration from 4 to 8%, drug release (cumulative amount) was improved from 20 (47.5%) to 30 (36%) μg/cm² after 24 h. Addition of 5% isopropanol to the above samples (4 and 8% loading) further increased drug release to 24 and 43 μg/cm². Results were in good agreement with the Korsmeyer‐Peppas theory for samples with 4 (% w/w) of ibuprofen. The highest percentage of drug release after 24 h was 59% for the sample with 4% drug loading compared to 50% for the sample with 8% drug loading, both with 5% isopropanol. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Effects of organically modified nanoclay on the transport properties and electrochemical performance of acid‐doped polybenzimidazole membranes

Nanocomposite polyelectrolyte membranes based on phosphoric acid (H₃PO₄) doped polybenzimidazoles (PBIs) with various loading weights of organically modified montmorillonite (OMMT) were prepared and characterized for direct methanol fuel cell (DMFC) applications. X‐ray diffraction analysis revealed the exfoliated structure of OMMT nanolayers in the polymeric matrices. An H₃PO₄–PBI/OMMT membrane composed of 500 mol % doped acid and 3.0 wt % OMMT showed a membrane selectivity of approximately 109,761 in comparison with 40,500 for Nafion 117 and also a higher power density (186 mW/cm²) than Nafion 117 (108 mW/cm²) for a single‐cell DMFC at a 5M methanol feed. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Nanodiamonds and Their Applications in Cells

Diamonds owe their fame to a unique set of outstanding properties. They combine a high refractive index, hardness, great stability and inertness, and low electrical but high thermal conductivity. Diamond defects have recently attracted a lot of attention. Given this unique list of properties, it is not surprising that diamond nanoparticles are utilized for numerous applications. Due to their hardness, they are routinely used as abrasives. Their small and uniform size qualifies them as attractive carriers for drug delivery. The stable fluorescence of diamond defects allows their use as stable single photon sources or biolabels. The magnetic properties of the defects make them stable spin qubits in quantum information. This property also allows their use as a sensor for temperature, magnetic fields, electric fields, or strain. This Review focuses on applications in cells. Different diamond materials and the special requirements for the respective applications are discussed. Methods to chemically modify the surface of diamonds and the different hurdles one has to overcome when working with cells, such as entering the cells and biocompatibility, are described. Finally, the recent developments and applications in labeling, sensing, drug delivery, theranostics, antibiotics, and tissue engineering are critically discussed.     

Multi-Scaled Modeling the Mechanical Properties of Tubular Composites Reinforced with Innovated 3D Weft Knitted Spacer Fabrics

Textile composites of 3D integrated spacer configurations have been recently focused by several researchers all over the world. In the present study, newly-designed tubular composites reinforced with 3D spacer weft knitted fabrics were considered and the effects of their structural parameters on some applicable mechanical properties were investigated. For this purpose, two different samples of 3D spacer weft knitted textile types in tubular form were produced on an electronic flat knitting machine, using glass/nylon hybrid yarns. Thermoset tubular-shaped composite parts were manufactured via vacuum infusion molding process using epoxy resin. The mechanical properties of the produced knitted composites in term of external static and internal hydrostatic pressures were evaluated. Resistance of the produced composites against the external static and internal hydrostatic pressures was numerically simulated using multi-scale modeling method. The finding revealed that there is acceptable correlation between experimental and theoretical results.     

Minimising interference for scheduling two parallel machines with a single server

In this paper, we consider the problem of scheduling a set of jobs on two parallel machines with set-up times. The set-up has to be performed by a single server. The objective is to minimise the forced idle time. The problem of minimising the forced idle time (interference problem) is known to be unary NP-hard for the case of two machines and equal set-up and arbitrary processing times. We propose a mixed integer linear programming model, which describes a special class of schedules where the jobs from a list are scheduled alternatively on the machines, and a heuristic algorithm is tested on instances with up to 100,000 jobs. The computational results indicate that the algorithm has an excellent performance even for very large instances, where mostly an optimal solution is obtained within a very small computational time.