Improving the functionality of biodegradable food packaging materials via porous nanomaterials

Non-biodegradability and disposal problems are the major challenges associated with synthetic plastic packaging. This review article discusses a new generation of biodegradable active and smart packaging based on porous nanomaterials (PNMs), which maintains the quality and freshness of food products while meeting biodegradability requirements. PNMs have recently gained significant attention in the field of food packaging due to their large surface area, peculiar structures, functional flexibility, and thermal stability. We present for the first time the recently published literature on the incorporation of various PNMs into renewable materials to develop advanced, environmentally friendly, and high-quality packaging technology. Various emerging packaging technologies are discussed in this review, along with their advantages and disadvantages. Moreover, it provides general information about PNMs, their characterization, and fabrication methods. It also briefly describes the effects of different PNMs on the functionality of biopolymeric films. Furthermore, we examined how smart packaging loaded with PNMs can improve food shelf life and reduce food waste. The results indicate that PNMs play a critical role in improving the antimicrobial, thermal, physicochemical, and mechanical properties of natural packaging materials. These tailor-made materials can simultaneously extend the shelf life of food while reducing plastic usage and food waste.     

Antioxidant Activities of Free and Liposome-Encapsulated Green tea extracts on canola oil oxidation stability

In the present study, green tea extract was encapsulated in liposomes based on the Mozafari method (with no organic solvents) and characterized for its physicochemical properties (encapsulation efficiency, particle size, and Z-potential). Encapsulation efficiency, particles size, and Z-potential were determined to be 51.34, 419 nm, and -57 mV, respectively. Total polyphenol content of the green tea by Folin-Ciocalteu's phenol reagent was measured as 164.2 mg gallic acid/g extract. Free radical scavenging activities of free and liposomal extracts were 90.6 and 93.4%, respectively, using the DPPH method. Antioxidant activity of the ethanolic extract of green tea in free and liposomal forms with concentrations of 200, 600, and 1000 mg L⁻¹ were assessed on oxidative stability of the canola oil at 60 °C for 0, 4, 8, 12, 16, 20, 24, 28, and 32 days. Results were compared to results of synthetic antioxidant butylated hydroxytoluene at 200 mg L⁻¹. To assess antioxidant activity on canola oil stability, peroxide, thiobarbitoric acid, and anisidine values were assessed as well as the total oxidation value and rancimat test. Results showed that the liposomal green tea extract was more effective than the free extract. Furthermore, a 600 mg L⁻¹ concentration of the green tea extract showed a significant antioxidant activity, compared to other extract concentrations. Increasing storage time and various concentrations of the ethanolic green tea extracts included significant effects on canola oil stability (P ≤ 0.05). Results demonstrated that the green tea extract could be used as an effective antioxidant. Free and liposomal extract (at 600 mg L⁻¹) resulted in stronger functionality than the synthetic antioxidant butylated hydroxytoluene.     

A new stress-updating algorithm for viscoplasticity

Material behavior beyond the elastic limit can be rate-dependent, and this rate sensitivity can be captured by the viscoplastic material models. To describe the viscoplastic material behavior in structural analysis, an efficient numerical framework is necessary. In this paper an algorithm is proposed for metals for which von Mises yield surface along with Peri?’s viscoplastic model is employed. The efficiency and accuracy of the technique is examined by comparison with different numerical studies. The convergence rate of the proposed algorithm is investigated. Characteristics of the viscoplastic behavior such as relaxation are illustrated in the selected case studies. Finally, application of the algorithm in practice is demonstrated by a boundary value problem.

     

QoS-enabled TCP for software-defined networks: a combined scheduler-per-node approach

The Journal of Supercomputing - Software-defined network (SDN) can ease the implementation of QoS concept by introducing a flexible and manageable mechanism to overcome the TCP pacing in the...     

Investigation of Size and Shape Dependencies of Phase Diagrams of the Ising Nanofilms and Nanotubes on the Honeycomb Lattice Using Cellular Automata Simulation Approach

Size and shape dependencies of phase diagrams of the Ising nanofilms and nanotubes on the honeycomb lattice are investigated by means of probabilistic cellular automata simulation based on Glauber algorithm. The values of reduced critical temperature, K _c = k _B T _c/J (where k _B and J are the Boltzmann constant and nearest-neighbor coupling, respectively), for both nanofilms and nanotubes, are obtained at the different sizes of the lattices and the dependency of K _c to the number of layers is studied. By increasing the number of layers K _c increases but for number of layer more than 8, the critical temperature increases very slowly. We have shown that between two isotropic nanotubes with the same number of spins, the ones with greater diameter (more spins on the edge) have larger critical temperature. For equal size of lattices, the obtained values of K _c for nanotube are greater than the nanofilm, but for large sizes, this difference disappears.     

A hybrid denoising algorithm based on shearlet transform method and Yaroslavsky’s filter

In this paper, we have proposed a hybrid denoising algorithm based on combining of the shearlet transform method, as a pre-processing step, with the Yaroslavsky’s filter, as a kernel smoother, on a wide class of images with various properties such as thin features and textures. In the other word, proposed algorithm is a two-step algorithm, where in the first step the image is filtered by shearlet transform method and in the second step the weighted Yaroslavsky’s filter is applied on result of first step. The weight coefficients of the Yaroslavsky’s filter are achieved by pixel similarities in the denoised image from the first step. The theoretical results are confirmed via simulations for 2D images corrupted by additive white Gaussian noise. Experimental results illustrate that proposed hybrid method has good effect on suppressing the pseudo-Gibbs and shearlet-like artifacts can obtain better performance in terms of mean square error (MSE), peak signal to noise ratio (PSNR) and structural similarity (SSIM) index rather than existing state-of-the-art methods.     

A new newsvendor policy model for dual-sourcing supply chains by considering disruption risk and special order

Newsvendor model is one of the most important issues in inventory models. In this paper, we investigate a newsvendor model without lead time, which have difference between distributer and wholesale/retailer. At the end of day, the residual products of newsvendor sold to a secondary market at a unit salvage value. Also, the amount of orders that cannot be met, should be paid the penalty for each unit. In addition, in each one of channels, the percent of these orders cannot be met by the distributer. Then, the newsvendor provides the difference between the amount that ordered to distributor and the amount that met in the occurrence of interruptions risk as a special order from the manufacturer, more expensive than the price of distributor. The limitations of the study are the procurement budget that used for special order. Finally, the model is applied in a real case as a numerical example to determine order amount that maximize profit and is solved by Maple 15. The Kuhn–Tucker method was used to illustrate the optimal points that have necessary condition. Also, the hessian matrix was used to illustrate the optimal points that have sufficient condition for optimization. Consequently, the considered points are global optimum. The main factor in the disruption risk that effect on the ordering amount and profit, are including the probability of appearing of disruption \((p_i)\) and a percent of ordering amount which are met in the case of appearing of disruption \((y_i)\). Therefore, the analysis of sensitivity has been done on two parameters of \(p_i\) and \(y_i\) by using contour curves. According to result of solved problem, the change of disruption appearance reduced. Finally, the proposed method besides being simple is so exact which is sensible in the solved problems.