Silicon Photonic Nanowire Soliton-Effect Compressor at 1.5 $mu$m

Soliton-effect compression of femtosecond optical pulses in a silicon photonic nanowire at 1.5 mum is numerically investigated. A region of anomalous group velocity dispersion, small third-order dispersion, and large nonlinearity of silicon is used to show compression of 30-fs input pulses to 1 fs. Large nonlinearity of silicon allows for compression of input pulses with subnanojoule energies.     

Preparation of Ag-Al₂O₃ nano structures by combustion method and investigation of photocatalytic activity

In this research, Ag-Al₂O₃ nanostructures have been prepared via combustion synthesis and ammonium acetate and urea have been applied as fuels. The prepared Ag-Al₂O₃ nanostructures were characterized by DTA, XRD, SEM, TEM, and BET spectroscopy. The effect of different ratios of silver to alumina and fuel percentage on morphology and particle size of prepared products were investigated. The results showed that using ammonium acetate fuel led to the production of Ag-γ-Al₂O₃ nanocompounds, while using urea produced Ag-α-Al₂O₃. Also, the photocatalytic activity of Ag-Al₂O₃ nanostructures for Congo red degradation was evaluated by UV-Vis diffuse reflectance spectroscopy. The photocatalytic activity of Ag-Al₂O₃ was examined under UV-Vis irradiation and showed significant photocatalytic efficiency.     

A novel microfluidic high-throughput resistive pulse sensing device for cells analysis

Microfluidic impedance-based devices offer a simple method for counting and sizing particles and cells in fields of biomedical research and clinical diagnosis. In this work, we present design, fabrication and operational characteristics of a novel high throughput original MEMS-based Coulter counter. This microfluidic device possesses two sub channels including two pairs of coplanar Au/Cr electrodes in each channels which allows double detection of the particles simultaneously and increases the throughput. The present design provides minimizing the cross talk and obviating the need for hydrodynamic focusing of the sample particles by adjusting Y shape insulation obstacle in direction of flow. Moreover, reducing coincidence events and removing electrode polarization effect were purposed by applying optimum sizes for electrodes considering the ease of fabrication and low costs. The reliability of the novel device was evaluated for polystyrene particles and cancer cells in conductive solutions. Results, which were recorded as relative resistance pulses across four sensing zones, illustrate the capability of the double-channel proposed device in detecting, counting and sizing 10 and 20 µm polystyrene particles. The superiority of present design was proved by relative counting error of below 3 and 11% for the 10 µm and 20 µm particles, respectively and a throughput of hundreds particles per second. Aiming at demonstrating the functionality of the proposed device in the biomedical area, counting of SP2/0 cells was performed. The measured counting outputs for cells in the size range of 5.63–17.6 µm were validated with results of hemocytometer cell counter, with relative error less than 7%.

     

Pervaporation of toluene and iso‐octane through poly(vinyl alcohol)/graphene oxide nanoplate mixed matrix membranes: Comparison of crosslinked and noncrosslinked membranes

Removal of aromatic compounds from fuel is an essential requirement in new environmental policies. In the present study, poly(vinyl alcohol)/graphene oxide (GO) mixed matrix membranes were prepared and applied to the separation of toluene from iso‐octane by pervaporation, considering the similarity and interaction between graphene and aromatics. The effects of crosslinking and GO content on separation efficiency have been investigated in detail. Owing to the high affinity of GO with toluene through s and π bonds, the selectivity of the membranes was increased by incorporating a low amount of GO. The results also indicated that noncrosslinked membranes have higher selectivity and permeation flux due to higher crystallinity and also have lower mechanical properties. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45853.     

Influence of electric field strength on structure,microstructure, and electrical properties of flash sintered 8% mol Yttria-stabilized zirconia as a solid oxide fuel cell electrolyte

To study the effect of electric field on the characteristics of flash sintered materials, 8% mol. Yttria-stabilized zirconia (8YSZ) was isothermally flash sintered under various electric field strengths as a solid oxide fuel cell (SOFC) electrolyte. Structural, microstructural, and electrical characteristics were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), and Electrochemical impedance spectroscopy (EIS), respectively. Results show that the electric field did not affect the relative density of flash sintered 8YSZ. Electric fields stronger than 300 V cm^?1, however, transformed the cubic structure to tetragonal. Microstructural studies show that the average grain size of samples is independent of the applied electric field strength. Electrochemical impedance spectroscopy showed changes in the grain boundary characteristics upon using the electric field for flash sintering. Oxygen vacancy concentration in the grain boundary of flash sintered samples was more than ten times higher than conventionally sintered ones, which improved the conductivity in flash sintered samples.     

Implementation of a square‐root filtering approach in marginalized particle filters for mixed linear/nonlinear state‐space models

Marginalized particle filter (MPF) takes advantage of both Kalman filter and particle filter frameworks to estimate nonlinear state‐space models with reduced number of calculations in comparison to particle filter. However, due to existence of Kalman filter framework inside MPF, some limitations are introduced in implementation of MPF especially in embedded systems with finite numerical accuracies. In this paper, for the first time, we propose a novel square‐root filtering strategy for MPFs to alleviate these restrictions using modified factorization. Typical square‐root Kalman filters cannot be employed inside MPF due to the presence of minus operations in some equations of MPF. However, our method can be easily implemented inside the MPF structure. The proposed method can be used in any application that employs MPFs to estimate the mixed linear/nonlinear state‐space models. In order to demonstrate its usefulness, we employed the proposed square‐root filtering method inside a marginalized particle extended Kalman filter (MP‐EKF) structure, which was specifically designed for ECG denoising. The experimental results showed that, in the field of ECG denoising, the square‐root MP‐EKF performs more consistently than MP‐EKF in white Gaussian noises.     

Effects of Soy and Corn Flour Addition on Batter Rheology and Quality of Deep Fat-Fried Shrimp Nuggets

In this paper, the effects of soy and corn flour (5 and 10% w/w) addition to the batter formulation on the quality of deep fat-fried shrimp nuggets were evaluated. Rheological properties of batters, coating pick-up, moisture content, and oil content of the samples were determined. Shrimp nuggets were fried at 150 °C, 170 °C, 190 °C, for 1, 2, 3, 4, and 5 min. The coating pick-up, oil and moisture content were found to be directly proportional to batter viscosity. All batters were found to show shear thinning behavior by exhibiting flow behavior index ≤ 1. The batters were modeled as power law fluids. Batter formulation, frying time, and temperature significantly (p < 0.01) affected moisture and oil content of shrimp nuggets. Soy flour added batters provided the highest consistency index, 7.595 and 10.635 Pa.sⁿ for 5% and 10% soy flour added, respectively. Soy flour was found to be an effective ingredient in decreasing oil content of fried nuggets. Batters containing 5% corn flour showed the lowest moisture content and the highest oil content among all the formulations. The mean moisture and fat content of shrimp nuggets coated with batter contained 10% soy and 5% corn flour, fried at 190 °C, for 5 min were 0.59 ± 0.022, 0.480 ± 0.029 and 0.149 ± 0.035, 0.346 ± 0.024 (g/g db), respectively.