The fabrication of a novel film based on polycaprolactone incorporated with chitosan and rutin: potential as an antibacterial carrier for rainbow trout packaging

Food Science and Biotechnology - Rutin and chitosan could be utilized in the food industry owing to their antioxidant and antibacterial properties. This study was carried out to fabricate novel...     

An efficient architecture for scheduling flexible job-shop with machine availability constraints

This paper investigates flexible job-shop problem (FJSP) with preventive maintenance activities. Makespan is considered as an optimal criterion for this problem. The contribution of this study could be divided into two parts: (1) since the preventive maintenance policies are not pondered in most prior FJSPs, we apply an enforceable and easily extendable preventive maintenance policy on FJSP; (2) in order to figure the problem out, an effective learnable genetic architecture, LEGA, which is established in previous articles for FJSPs, is expanded to integrated FJSP and preventive maintenance which is named preventive maintenance and LEGA. All operators and parameters are then calibrated by means of the Taguchi experimental design. For the evaluation of the proposed architecture, a benchmark with conscientious care is employed.     

Punching shear strength of interior slab–column connections strengthened with carbon fiber reinforced polymer sheets

In this paper, punching shear strengthening of flat slabs using Carbon Fiber Reinforced Polymer (CFRP) sheets is studied. Fifteen specimens of reinforced concrete slabs were tested. Thirteen of them were strengthened by CFRP sheets and two specimens were kept as control specimens. Four of these strengthened specimens were tested under cyclic vertical loading. The width of CFRP sheets varied in different specimens. The CFRP sheets were located at the tension side of the slabs in two perpendicular directions. Vertical load was applied downward through a column stub using a hydraulic Jack. In all specimens, no rupture of CFRP sheets was observed. The test results showed that the use of CFRP sheet, in addition to steel reinforcing bars, as flexural reinforcement improves the punching shear strength of slabs. This improvement can be significant for the slabs made of high strength concrete and low steel reinforcement ratio. However, the improvement of punching shear strength due to FRP strengthening reduced under cyclic vertical loading. The test results were compared with the equations proposed by ACI 318 and BS 8110 Codes. The ACI Code underestimates the punching shear strength of slabs and this underestimation becomes more pronounced with the increase in the flexural reinforcement. The BS 8110 Code appropriately accounts for the effect of flexural reinforcement on punching shear strength of slabs. However, for the strengthened slabs, an equivalent reinforcement ratio should be used to include the effect of both steel and CFRP flexural reinforcement.     

In Situ Production of Fe-TiC Nanocomposite by Mechanical Activation and Heat Treatment of the Fe2O3/TiO2/C Powder

In this study, Fe-TiC nanocomposite was synthesized by carbothermic reduction of activated Fe₂O₃, TiO₂, and graphite powder mixture. The effect of 0, 5, and 20?h of high energy ball milling of mixture on the reduction process was also investigated. Comparing the results of the thermogravimetry analysis of milled and un-milled mixtures clearly showed that the reduction temperature decreased due to the milling process. XRD pattern of 20?h milled powder mixture proved that Fe-TiC nanocomposite was formed after the heat treatment of activated powder at 1100°C for 1?h under vacuum. The microstructure studies of the milled mixture by scanning electron microscope revealed homogenous distribution of TiC particles in the Fe matrix.     

Linear optical properties of ZnO nano particles synthesized by electrohydrodynamics atomization (EHDA) method

Zinc oxide nanoparticles were synthesized via Chemical Bath Deposition (CBD) method with and without high voltage electric field which is known as electrohydrodynamic atomization route. Three main different jet modes were selected with adjusting the applied voltages for decreasing the size of reaction media, including: Dripping, Cone Jet (3.28 kV) and Multi jet (7.12 kV). The products were characterized by means of powder X-ray diffraction (XRD), Transmission electron microscopy (TEM), UV–Vis absorption spectroscopy and photoluminescence (PL). The prepared nanoparticles have different morphologies in each mode. Smaller nanoparticles were produced when the modes were changed from dripping to cone jet and multi jet modes. By decrease in particle size a significance blue shift occurs in UV-absorption spectra of prepared samples. The driven band gap of the particles in each mode are: 3.31, 3.35 and 3.415 eV for dripping, cone jet and multi jet modes, respectively. Also based on PL results, all samples show the near-band-edge peaks in 433 nm. By decrease in size of produced nanoparticles a reduction in emitted light intensity occurs in the samples.     

A New Approach for the Development of Fast-analysis Proxies for Petroleum Reservoir Simulation

Abstract

The bottleneck of all processes that are using field-scale numerical simulators is the computationally expensive objective function evaluation. Hence, always a gap exists between simulation runs and real-time processing. In this study, a new approach is presented that uses online-adaptive artificial neural networks to develop proxies that mimic the behavior of the actual reservoir simulator. In this approach, initially Latin hypercube sampling is used and then an intelligent sample selection algorithm is developed to improve the online network prediction. The cited approach improves the surrogate model development in two directions. First, proxies can be used while they are developing and, second, samples are selected intelligently and this reduces computational cost.     

Preparation and characterization of chitosan based hydrogels containing cyclodextrin inclusion compounds or nanoemulsions of thyme oil

Hydrogels derived from natural polysaccharides are ideal scaffolds for use in biomedical applications. pH‐sensitive polyvinyl alcohol and chitosan hydrogels containing inclusion compounds of thyme oil (TM) with host methyl‐β‐cyclodextrin (MβCD) and hydroxypropyl‐β‐cyclodextrin (HβCD) and TM nanoemulsion (TM‐nano) were prepared via controlled, biocompatible and low cost freeze–thaw method. The structure of the hydrogels was characterized by Fourier transform IR spectroscopy and optical and scanning electron microscopy. The physicochemical properties of the hydrogels such as gel fraction, swelling ratio and tensile properties were measured. The water vapor transmission rate of the hydrogels indicated that they can maintain a moist environment over the wound bed. Encapsulation and release of antibacterial TM from the hydrogels were determined by UV spectroscopy. In all cases, hydrogels with lower amounts of TM evidenced slower and more controlled release. Different kinetic models were applied for evaluating the drug release mechanism. The antibacterial activity of the samples was studied by counting the number of both Gram‐negative and Gram‐positive bacteria surviving in a broth medium and the results proved the antibacterial activity of all prepared hydrogels. The results of an MTT (3‐(4,5‐dimethylthiazol‐2yl)‐2,5‐diphenyltetrazolium bromide) assay indicated more cell viability of TM‐nano hydrogels in comparison with those of TM‐βCD inclusion compounds. Cell attachment observations also showed great biocompatibility of TM‐nano hydrogels. The prepared hydrogels, especially those containing TM‐nano, might be used as potential wound dressings to improve the wound healing process. © 2019 Society of Chemical Industry