CISSKA-LSB: color image steganography using stego key-directed adaptive LSB substitution method

Multimedia Tools and Applications - Information hiding is an active area of research where secret information is embedded in innocent-looking carriers such as images and videos for hiding its...     

Microstructure and strengthening behavior in high content SiC nanowires reinforced SiC composites

In this study, the high-content SiC_nw reinforced SiC ceramic matrix composites (SiC_nw/SiC CMC) were successfully fabricated by hot pressing β-SiC and sintering additive (Al₂O₃-Y₂O₃) with boron nitride interphase modification SiC_nw. The effects of sintering additive content and mass fraction (5–25 wt%) of SiC_nw on the density, microstructure, and mechanical properties of the composites were investigated. The results showed that with the increase of sintering additives from 10 wt% to 12 wt%, the relative density of the SiC_nw/SiC CMC increased from 97.3% to 98.9%, attributed to the generated Y₃Al₅O₁₂ (YAG) liquid phase from the Al₂O₃-Y₂O₃ that promotes the rearrangement and migration of SiC grains. The comprehensive performance of the obtained composite with 15 wt% SiC_nw possessed the optimal flexural strength and fracture toughness of 524 ± 30.24 MPa and 12.39 ± 0.49 MPa·m^1/2, respectively. Besides, the fracture mode of the composites with 25 wt% SiC_nw content revealed a pseudo-plastic fracture behavior. It concludes that the 25 wt% SiC_nw/SiC CMC was toughened by the fiber pull-outs, debonding, bridging, and crack deflection that can consume plenty of fracture energy. The strategy of SiC nanowires worked as a main bearing phase for the fabrication of SiC/SiC CMC providing critical information for understanding the mechanical behavior of high toughness and high strength SiC nanoceramic matrix composites.     

High pressure-based hurdle interventions for raw and processed meat: a clean-label prospective

Today's consumers demand clean-label healthy products to which no artificial preservatives have been added. Distribution of fresh, safe raw meat or meat products requires reduced numbers of bacteria on its surface when it leaves the processing plant under strict maintenance of low temperatures throughout the supply chain. Means of controlling or even improving the food integrity aim to decontaminate the carcasses or products during or at the end of the production line. In the past decades, high-pressure processing (HPP) has been investigated as an alternative non-thermal preservation technology to match all these demands without compromising safety. HPP treatments could efficiently inactivate the vegetative microorganisms (related to foodborne diseases), but not spores. However, the combination of several non-thermal and conventional preservation techniques under the so-called hurdle technology has been explored to enhance their efficiency.     

Numerical Procedure for Fractional HBV Infection with Impact of Antibody Immune

The current investigations are presented to solve the fractional order HBV differential infection system (FO-HBV-DIS) with the response of antibody immune using the optimization based stochastic schemes of the Levenberg-Marquardt backpropagation (LMB) neural networks (NNs), i.e., LMBNNs. The FO-HBV-DIS with the response of antibody immune is categorized into five dynamics, healthy hepatocytes (H), capsids (D), infected hepatocytes (I), free virus (V) and antibodies (W). The investigations for three different FO variants have been tested numerically to solve the nonlinear FO-HBV-DIS. The data magnitudes are implemented 75% for training, 10% for certification and 15% for testing to solve the FO-HBV-DIS with the response of antibody immune. The numerical observations are achieved using the stochastic LMBNNs procedures for soling the FO-HBV-DIS with the response of antibody immune and comparison of the results is presented through the database Adams-Bashforth-Moulton approach. To authenticate the validity, competence, consistency, capability and exactness of the LMBNNs, the numerical presentations using the mean square error (MSE), error histograms (EHs), state transitions (STs), correlation and regression are accomplished.     

Synthesis and polymerization of 1,5-bis( N -carbazolyl)pentane with its structural and behavioral highlights

Carbazole, the well-known electron donor and hole-transporting organic light-emitting molecule was modified into 1,5-bis[N-carbazolyl]pentane (1,5-BNCP) by introducing the saturated pentane spacer. Such insertion fixed the certain space between growing polymer chains and demonstrated π–π stacking effect over its morphology and structure. Its contribution in improving the thermal stability and photosensitization was also investigated. The FT-IR and 1H NMR was used to characterize monomer. Morphology of subsequently polymerized material was seen under SEM. The position of polymerization and structural change were studied by FT-IR and XRD, respectively. Thermal study with reference to glass transition temperature and stability was analyzed by DSC and TGA. Optical properties of monomer and polymer were investigated by UV–visible and photoluminescent spectrophotometer. The material was found crystalline, thermally stable, highly photosensitized and white light emitter.     

Silver nanoparticles containing hybrid polymer microgels with tunable surface plasmon resonance and catalytic activity

Multi-responsive poly(N-isoprpylacrlamide-methacrylic acid-acrylamide) [P(NIPAM-MAA-AAm)] copolymer microgel was prepared by free radical emulsion polymerization. Silver nanoparticles were fabricated inside the microgel network by in-situ reduction of silver nitrate. Swelling and deswelling behavior of the pure microgels was studied under various conditions of pH and temperature using dynamic light scattering. A red shift was observed in surface plasmon resonance wavelength of Ag nanoparticles with pH induced swelling of hybrid microgel. The catalytic activity of the hybrid system was investigated by monitoring the reduction of p-nitrophenol under different conditions of temperature and amount of catalysts. For this catalytic reaction a time delay of 8 to 10min was observed at room temperature, which was reduced to 2 min at high temperature due to swelling of microgels, which facilitated diffusion of reactants to catalyst surface and increased rate of reaction.     

Synthesis and characterization of Ag@polycarbazole coaxial nanocables and their enhanced dispersion behavior

Ag@polycarbazole coaxial nanocables (CNCs) have been successfully fabricated by the oxidative polymerization of carbazole over Ag nanowires (NWs) in acetonitrile. The morphology of Ag NWs and CNCs was studied by employing a transmission electron microscope (TEM) and a scanning electron microscope (SEM), which showed them to be a monodisperse material. The thickness of the polymer sheath was found to be 5 nm to 8 nm by observation under a high-resolution transmission electron microscope (HR-TEM). Energy dispersive X-ray spectroscopy (EDS), FT-IR and Raman measurements were used to characterize the polymer sheath, which demonstrated it to be a carbon material in polycarbazole form. X-ray photoelectron spectroscopy (XPS) was used for an interfacial study, which revealed that Ag surface atoms remained intact during polymer growth. In the end, zeta potential showed that the dispersion stability of Ag NWs increased due to polymer encapsulation, which is significant to obtain a particular alignment for anisotropic measurement of electrical conductivity.     

In situ reactive compatibilization of aramid/polystyrene blends using amine‐functionalized polystyrene

High molecular weight aramid chains (Ar) were synthesized from aromatic diamine and diacid chloride. Amine functionality was introduced to polystyrene (PS) in two steps i.e., nitration followed by reduction producing amino functional polystyrene (APS) which serves as a reactive compatibilizer, being reactive with the Ar end‐groups. APS was characterized by FTIR, NMR spectral data, and exploited in the preparation of Ar/APS blends, and the effect of reactive compatibilization on blend morphology and interfacial adhesion was explored. Two blend systems Ar/PS and Ar/APS were investigated over a range of PS or APS ratios. To assess the effect of amine units incorporated in PS, on the compatibility with Ar; morphology, thermal, and mechanical properties were probed. Incorporation of reactivity into the system has resulted in significant refinement of the blend morphology and augmentation of thermal stability. The in situ generation of APS‐g‐Ar copolymers during solution mixing of APS and Ar was evaluated using spectroscopic analysis. In addition to stabilizing the microstructure, in situ compatibilization was found to alter the mechanical properties of the Ar/APS interface. Ar/APS blend containing 10 wt% APS was found to demonstrate optimum mechanical reinforcement as complemented by the optimal thermal and morphological profiles of 10 wt% Ar/APS blend. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers