Green synthesis of zinc oxide nanoparticles using Amygdalus scoparia Spach stem bark extract and their applications as an alternative antimicrobial,anticancer, and anti-diabetic agent

For the first time in this study, Zinc oxide nanoparticles were biosynthesized by the eco-friendly and cost-effective procedure using Amygdalus scoparia stem bark extract then used as antibacterial, antifungal, anticancer, and anti-diabetic agents. The characterization techniques confirmed the biosynthesis, crystalline nature, structure, size, elemental composition of ZnO NPs and bioactive compounds that exist in A. scoparia extract accounting for Zn²⁺ ion reduction, capping and stabilization of ZnO NPs. The ZnO NPs displayed remarkable inhibitory activity against E. coli, E. aerigenes, S. aureus, P. oryzae, F. thapsinum, and F. semitectum compared to antibiotic standards. The ZnO NPs showed significant inhibitory effects on cancer cell lines, while it had no toxic effect on Vero normal cell line. The ZnO NPs (30 mg/kg)-treated diabetic rats showed significantly higher levels of insulin and lower AST, ALT and blood glucose compared with the STZ induced diabetic group and other treated groups (P < 0.05). The ZnO NPs- and extract-treated rats showed significantly higher levels of IR, GluT2, and GCK expression and lower TNFα expression compared with the STZ induced diabetic rats. Our findings showed that ZnO NPs represented an outstanding performance for biological applications.     

Curcumin and Liver Disease: from Chemistry to Medicine

Curcumin, the natural yellow‐colored active principle, also called turmeric yellow, extracted from the perennial herb Curcuma longa L., has potent biological and pharmacological properties such as antioxidant, anti‐inflammatory, antifungal, antibacterial, anti‐ischemic, antitumor, and anticancer actions. The molecular mechanism of the hepatoprotective action of curcumin is due to its antioxidant properties and inhibitory activity against nuclear factor (NF)‐κB that regulates different proinflammatory and profibrotic cytokines. Overall, scientific reports demonstrate that curcumin has high therapeutic ability for treating hepatic disorders. Here is a systematic discussion of the hepatoprotective activity of curcumin and its possible mechanisms of actions.     

Two‐Phase Sequential Simulation of a Fluidized Bed Reformer

A two‐phase flow model is adapted in order to predict the performance of a fluidized bed reformer using the sequential modular simulator. Since there are physical and chemical phenomena interacting in the reformer, two sub‐models appear to be necessary to describe the overall model. These are the hydrodynamic and reaction sub‐models. The hydrodynamic sub‐model is based on the dynamic two‐phase model and the reaction sub‐model is derived from the literature. In the overall model, the bed is divided into several sections. At each section, the flow of the gas is considered as plug flow through the bubble phase and to be perfectly mixed through the emulsion phase. Two sets of experimental data from the literature at different hydrodynamic regimes were used in order to validate the proposed model. A close agreement was observed between the model predictions and the experimental data. The model proposed in this work may be used as a framework for the development of sophisticated models for non‐ideal reactors inside process simulators.     

Effect of two-step severe plastic deformation on the microstructure and mechanical properties of commercial purity titanium

The present work investigates the microstructural and mechanical properties of commercial purity titanium after processing by a two-step severe plastic deformation procedure entailing warm equal channel angular pressing (ECAP) followed by cold rolling at liquid nitrogen temperature (LNT). The effect of subsequent cold rolling at room temperature is also investigated for comparison. After 10 passes of ECAP, an ultrafine-grained structure with average grain size of 213 nm was achieved. Subsequent cold rolling at LNT led to further refinement and decreased the grain size to 114 nm. Under these conditions, the material displayed high tensile strength of 995 MPa and high elongation to failure of 23%. These promising mechanical properties were interpreted in terms of characteristics of the microstructure: grain refinement, increased dislocation density, and a high fraction of high angle grain boundaries.     

Halloysite Nanotubes Modified by Fe3O4 Nanoparticles and Applied as a Natural and Efficient Nanocatalyst for the SymmetricalHantzsch Reaction

Halloysite as an impressive natural eco-friendly nanotube with aluminosilicate structure has been investigated recently due to its unique features such as specific morphology and excellent bio-adaptability. In this research, Fe₃O₄ nanoparticles have been loaded on the tubular halloysite by co-precipitation method in order to synthesis magnetic halloysite (Hal-Fe₃O₄₎. To characterize this recoverable nanocatalyst, applicable analyses such as Fourier-transform infrared (FT-IR) spectroscopy, energy-dispersive X-ray (EDX) analysis, field-emission scanning electron microscopy (FE-SEM) images, X-ray diffraction (XRD) pattern, Thermogravimetric analysis (TGA) and vibrating sample magnetometer (VSM) curves have been carried out. The results confirmed that Fe₃O₄ nanoparticles with cubic structure, and uniform distribution, were located at halloysite nanotubes (HNTs). This aluminosilicate nanocomposite with high thermal stability, crystalline structure, and stable morphology was evaluated as a heterogeneous catalyst in the symmetrical Hantzsch reaction for the first time. Easy synthesis process, green media, high performance, recoverable catalyst and reusing of the Hal-Fe₃O₄ as a nanocatalyst for 8 times are the main features of this protocol.

     

Mutual neighbors and diagonal loading-based sparse locally linear embedding

In this study, a new Locally Linear Embedding (LLE) algorithm is proposed. Common LLE includes three steps. First, neighbors of each data point are determined. Second, each data point is linearly modeled using its neighbors and a similarity graph matrix is constructed. Third, embedded data are extracted using the graph matrix. In this study, for each data point mutual neighborhood conception and loading its covariance matrix diagonally are used to calculate the linear modeling coefficients. Two data points will be named mutual neighbors, if each of them is in the neighborhood of the other. Diagonal loading of the neighboring covariance matrix is applied to avoid its singularity and also to diminish the effect of noise in the reconstruction coefficients. Simulation results demonstrate the performance of applying mutual neighborhood conception and diagonal loading and their combination. Also, the results of applying the mutual neighborhood on Laplacian Eigenmap (LEM) demonstrate the good performance of the proposed neighbor selection method. Our proposed method improves recognition rate on Persian handwritten digits and face image databases.     

Study of Electronic Structure,Magnetism, and Half-Metallicity of New Heusler Compounds CsTmO<Subscript>2</Subscript> (Tm = Fe,Co, Ni,and Cu)

The density functional calculations were performed using the full-potential linearized augmented plane wave (FPLAPW) method for new Heusler alloys CsTmO₂ (Tm = Fe, Co, Ni, and Cu). All compounds were stable in FM AlCu₂Mn-type structure. Results revealed that these alloys can be experimentally synthesized according to the calculated cohesive and formation energies. CsTmO₂ (Tm = Fe, Co, Ni, and Cu) alloys in AlCu₂Mn-type and CuHg₂Ti-type structures were half-metallic ferromagnets. The origin of half-metallicity in CsNiO₂ alloy was also discussed. The total magnetic moment of CsTmO₂ (Tm = Fe, Co, Ni, and Cu) alloys in both structures were 3 μ_B per formula unit and obeyed the Slater-Pauling rule (M_tot =?22 ? Z_tot). The relationship between the magnetism and half-metallicity of all compounds and the lattice constants was also studied. The half-metallic character in combined alloys CsTmO₂ (Tm = Fe, Co, Ni, and Cu) improved in comparison with Heusler alloys including transition metals which indicated that they may be good candidates for practical applications in spintronics.     

Nonlinear fractional‐order power system stabilizer for multi‐machine power systems based on sliding mode technique

This paper presents two novel nonlinear fractional‐order sliding mode controllers for power angle response improvement of multi‐machine power systems. First, a nonlinear block control is used to handle nonlinearities of the interconnected power system. In the second step, a decentralized fractional‐order sliding mode controller with a nonlinear sliding manifold is designed. Practical stability is achieved under the assumption that the upper bound of the fractional derivative of perturbations and interactions are known. However, when an unknown transient perturbation occurs in the system, it makes the evaluation of perturbation and interconnection upper bound troublesome. In the next step, an adaptive‐fuzzy approximator is applied to fix the mentioned problem. The fuzzy approximator uses adjacent generators relative speed as own inputs, which is known as semi‐decentralized control strategy. For both cases, the stability of the closed‐loop system is analyzed by the fractional‐order stability theorems. Simulation results for a three‐machine power system with two types of faults are illustrated to show the performance of the proposed robust controllers versus the conventional sliding mode. Additionally, the fractional parameter effects on the system transient response and the excitation voltage amplitude and chattering are demonstrated in the absence of the fuzzy approximator. Finally, the suggested controller is combined with a simple voltage regulator in order to keep the system synchronism and restrain the terminal voltage variations at the same time. Copyright © 2014 John Wiley & Sons, Ltd.     

A low-power and robust quaternary SRAM cell for nanoelectronics

This paper presents an efficient and low-power quaternary static random-access memory (SRAM) cell based on a new quaternary inverter. For implementation, carbon nanotube field-effect transistors (CNTFETs) are used. Stacked CNTFETs are appropriately used in the proposed design to achieve a considerably low static power dissipation. The proposed SRAM has a more significant static noise margin due to its single quaternary digit line, and it is appropriate for MVL SRAM design as there are more than two stable states. The simulation results using Synopsys HSPICE with 32 nm Stanford comprehensive CNTFET model demonstrate the correct and robust operation of the proposed designs even in the presence of major process variations. In addition, the proposed SRAM cell is applied in a 4?×?4 SRAM array structure to demonstrate the efficiency of the proposed SRAM. The results indicate that the proposed design significantly lowers the power consumption and provides comparable static noise margins compared to the other state-of-the-art CNTFET-based circuits.