Effect of Lithium Perchlorate on the Optoelectrical and Thermal Properties of Poly(Vinylpyrrolidone)/Nano-Cesium Aluminate Solid Polymer Electrolytes

Solid polymer electrolyte (SPE) of polyvinylpyrrolidone (PVP) with varying amounts, namely, 5, 10, and 15?wt% of lithium perchlorate (LiClO₄) as an electrolyte and 8?wt% cesium aluminum oxide (CsAlO₂) nanoparticle have been fabricated by solution intercalation technique. The optoelectrical behaviors of the SPE films have been evaluated using UV–visible spectroscopy. The UV–visible spectral studies revealed the UV light-absorbing nature of NC films with considerable visible transparency. The chemical structure and morphological behaviors of PVP/8?wt% of CsAlO₂–LiClO₄ SPE films have been established by Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy, respectively. The AC conductivity of the SPEs was evaluated at room temperature by digital LCR meter in the frequency range 100 Hz–5?MHz. The thermal behaviors such as T_g and degradation patterns of the SPEs have been evaluated using differential scanning calorimetric analysis and thermogravimetric analysis, respectively.     

Fuzzy reasoning model to improve face illumination invariance

Enhancing facial images captured under different lighting conditions is an important challenge and a crucial component in the automatic face recognition systems. This work tackles illumination variation challenge by proposing a new face image enhancement approach based on Fuzzy theory. The proposed Fuzzy reasoning model generates an adaptive enhancement which corrects and improves non-uniform illumination and low contrasts. The FRM approach has been assessed using four blind-reference image quality metrics supported by visual assessment. A comparison to six state-of-the-art methods has also been provided. Experiments are performed on four public data sets, namely Extended Yale-B, Mobio, FERET and Carnegie Mellon University Pose, Illumination, and Expression, showing very interesting results achieved by our approach.     

Determination of cytocompatibility and osteogenesis properties of in situ forming collagen-based scaffolds loaded with bone synthesizing drug for bone tissue engineering

Bone tissue engineering using in situ forming 3D scaffolds can be an alternative to surgically treated scaffolds. This work aimed to develop in situ forming scaffolds using poly (lactic-co-glycolic acid) and a bone synthesizing drug (risedronate) with or without the porogenic agent (collagen). Hybrid scaffolds were formed through solvent-induced phase inversion technique and were morphologically evaluated using scanning electron microscopy (SEM). The effect of scaffolds on Saos-2 cell line viability using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide test besides their effect on cell growth using fluorescence microscope was assessed. Furthermore, alkaline phosphatase (ALP) activity as well as Ca²⁺ deposition on the scaffolds was evaluated. SEM images revealed the porous structure for collagen-based scaffolds. Saos-2 cell proliferation was significantly enhanced with risedronate-loaded scaffolds compared to those lacking the drug. Porous collagen-based scaffolds were more favorable for both the cell growth and the promotion of ALP activity. Furthermore, collagen-based scaffolds promoted the Ca²⁺ deposition compared to their counterparts without collagen. Such results suggest that collagen-based scaffolds offer excellent biocompatibility for bone regeneration, where this biocompatible nature of scaffold leads to the proliferation of cells that lead to the deposition of mineral on the scaffold. Such in situ forming 3D scaffolds provide a promising noninvasive approach for bone tissue engineering.     

Formation of chlorinated aromatics by reactions of Cl*, Cl2, and HCl with benzene in the cool-down zone of a combustor

Conversion of benzene to chlorobenzenes and monochlorophenols by reaction with chlorine radicals (Cl*) in the cool-down zone of a plug-flow combustor has been studied, and a mechanistic analysis of the initial steps of the oxy-chlorination process is proposed. Superequilibrium concentrations of Cl* are formed during combustion of chlorocarbon species and persist at significant concentration levels even after a substantial reduction in the flue gas temperature (T = 500-700 degrees C). At these temperatures, Cl* attack on benzene present in trace concentrations (initial benzene concentration of 300 ppmv or 1080 ppmv were used for the experiments) in the post-flame gas is shown to result in stable chlorinated products (chlorobenzenes and chlorophenols) and loss of benzene. These results suggest that Cl* attack on trace level aromatics and possibly other organic species may be the initial step in the formation of a broad class of chlorinated and oxy-chlorinated pollutants in the post combustion zone.     

Synthesis of fluorescence active pyridinedicarbonitriles and studying their application in functional paper

The present study deals with synthesis of novel 6-alkoxy-2-amino-3,5-pyridinedicarbonitrile derivatives, as a safety marker. The fluorescence properties of the synthesized heterocyclic compounds were determined. The fluorescence quantum yield (?_s) of these active compounds, relative to the fluorescence quantum yield of quinine sulfate, is reached at ~ 0.83. Application of representative synthesized examples on cotton linters and/or bagasse-based paper sheets was adopted in the present study, in an attempt to obtain safety paper from non-wood fibrous pulps. The quality of the obtained safety paper was evaluated based on both fluorescence impact and strength properties. The successful application of these fluorescent active compounds in the production of functionalized paper sheets, from bagasse pulp- cotton linter blend is demonstrated.     

Simple analytical model and efficiency improvement of polysilicon solar cells with porous silicon at the backside

The present study developed a simple analytical model to simulate the performance of polysilicon solar cells with porous silicon (PS) layer at the backside. It analytically solved the complete set of equations necessary for the determination of the photocurrent generated under the effect of the reflected light. It also investigated the contribution of the light absorbed by the PS layer and explored the effect that the latter’s number of double porosities and high porosity have had on photovoltaic parameters. The findings suggest that the photovoltaic parameters increase with the number of double porosities that the layer might have in a given structure. When the PS layer is formed by three-double porosity layers 20%/80% and for a 5 μm-thick film c-Si, the backside reflector gives a total improvement of about 2.65 mA/cm² in photocurrent density and 1.4% in cell efficiency. This improvement can even be of much more important for well passivated grain boundaries and back contact of solar cells.     

Influence of capsule shell composition on the performance indicators of hypromellose capsule in comparison to hard gelatin capsules

The purpose of this study was to assess the in vitro performances of “vegetable” capsules in comparison to hard gelatin capsules in terms of shell weight variation, reaction to different humidity conditions, resistance to stress in the absence of moisture, powder leakage, disintegration and dissolution. Two types of capsules made of HPMC produced with (Capsule 2) or without (Capsule 3) a gelling agent and hard gelatin capsules (Capsule 1) were assessed. Shell weight variability was relatively low for all tested capsules shells. Although Capsule 1 had the highest moisture content under different humidity conditions, all capsule types were unable to protect the encapsulated hygroscopic polyvinylpyrrolidone (PVP) powder from surrounding humidity. The initial disintegration for all Capsule 1 occurred within 3?min, but for other types of capsules within 6?min (n?=?18). Dissolution of acetaminophen was better when the deionized water (DIW) temperature increased from 32 to 42?°C in case of Capsule 1, but the effect of temperature was not significant for the other types of capsules. Acetaminphen dissolution from Capsule 1 was the fastest (i.e. >90% in 10?min) and independent of the media pH or contents unlike Capsule 2 which was influenced by the pH and dissolution medium contents. It is feasible to use hypromellose capsules shells with or without gelling agent for new lines of pharmaceutical products, however, there is a window for capsule shells manufacturing companies to improve the dissolution of their hypromellose capsules to match the conventional gelatin capsule shells and eventually replace them.     

Modeling and Management of Batteries and Ultracapacitors for Renewable Energy Support in Electric Power Systems–An Overview

Abstract—Energy storage devices and systems are playing a major role in all electrical systems from small electronics devices and automotive systems to the utility grid. The main objective of this article is to review energy storage devices, management, control, interface, and demonstrations for electrical power systems. Various types of energy storage systems are discussed, but the main focus is on batteries and ultracapacitors. Different types of batteries and their electrical models are explained. Three major types of ultracapcitors are also discussed. The battery management system and its functions, controls, and hardware are discussed. Various power electronics-based interface systems for battery and ultracapcitor charging and discharging are presented. Applications of energy storage systems for utility applications, including renewable firming, power shifting, and ancillary services, are discussed.