Dielectric Investigation of NaLiS Nanoparticles Loaded on Alginate Polymer Matrix Synthesized by Single Pot Microwave Irradiation

Sodium lithium sulfide (NaLiS) nanocomposite have been successfully synthesized by using microwave-irradiation (MWI) method. The study suggested that the application of microwave heating is to produce homogeneous and fine NaLiS nanocomposite which were achieved by using the precursors of lithium acetate and thioacetamide in the presence of sodium alginate biopolymer. FTIR is used to identify the structural coordination and functional groups of the prepared nanocomposite. The structural property of NaLiS particles was investigated by XRD. The surface morphology and elemental composition of synthesized material was confirmed by SEM and EDX analyses. The optical property was studied by using UV–Vis spectrophotometer. Thermal stability of as prepared sample was studied by TGA/DTG analysis. Electrical transport studies of the prepared nanocomposite have been analyzed for various temperatures. NaLiS nanocomposite has ionic conductivity of ~?10^?7 S cm^?1 at 35 °C which is six orders of magnitude higher than that of micro sized bulk Li₂S (~?10^?13 S cm^?1).     

Separation of particles using acoustic streaming and radiation forces in an open microfluidic channel

In this study, a method to separate particles, within a small sample, based on size is demonstrated using ultrasonic actuation. This is achieved in a fluid, which has been deposited on a flat surface and is contained by a channel, such that it has a rectangular wetted area. The system utilises acoustic radiation forces (ARFs) and acoustic streaming. The force field generates two types of stable collection locations, a lower one within the liquid suspension medium and an upper one at the liquid–air interface. Acoustic streaming selectively delivers smaller particles from the lower locations to the upper ones. Experimental data demonstrate the ability to separate two sets of polystyrene microparticles, with diameters of 3 and 10 μm, into different stable locations. Methods to reduce migration of larger particles to the free surface are also investigated, thereby maximising the efficiency of the separation. Extraction of one set of 99 % pure particles at the liquid–air interface from the initial particle mixture using a manual pipette is demonstrated here. In addition, computational modelling performed suggests the critical separation size can be tuned by scaling the size of the system to alter which of ARFs and acoustic streaming-induced drag forces is dominant for given particle sizes, therefore presenting an approach to tunable particle separation system based on size.     

Classification of Clickjacking Attacks and Detection Techniques

ABSTRACT

Among many existing security threats, clickjacking attacks are the least understood and one of the common emerging security threats on the Web. A clickjacking attack lures users to click on objects transparently placed in malicious Web pages that may lead to unwanted operations on the legitimate Websites without the knowledge of the users. In particular, victims can be tricked to click on objects from various Websites such as social networks (Facebook, Twitter), shopping (Amazon), and online banking. Therefore, clickjacking attacks need to be addressed to mitigate these unwanted consequences. To combat the clickjacking attacks, it is necessary to understand how clickjacking attacks occur in the real world along with the comparative performance of the state-of-the art solutions.

In this article, we discuss various basic and advanced clickjacking attacks. We then discuss a number of client, server, and proxy-level approaches that can be employed to combat clickjacking attacks. We also highlight the advantages and disadvantages along with attack type coverage information. The findings should enable security practitioners to be aware of the most recent development in this area and choose the appropriate defense mechanism based on their needs.     

Preparation and Characterization Studies of Nanostructured CdO Thin Films by SILAR Method for Photocatalytic Applications

This work reports the preparation of cadmium oxide (CdO) thin films with different molar concentrations on glass substrate by simple and low cost SILAR (Successive Ionic Layer Adsorption and Reaction) method. The characterization, XRD pattern confirmed the presence of polycrystalline CdO in the deposited thin films with the cubic structure. The surface morphology and elemental composition of prepared thin films have been examined by scanning electron microscopy equipped with energy dispersive X-ray (EDX) analysis system. The optical property of the films was analyzed by UV–visible spectroscopy. The band gap of the deposited thin films was estimated by Tauc’s plot and it was found to be 2.6–2.8 eV. The prepared thin films were examined for the decomposition of the Methylene Blue (MB) dye which was visualized by UV-Visible spectroscopy, by decreasing the intensity of absorbance and concentration.     

High-performance nickel sulfide modified electrode material from single-source precursor for energy storage application

High-performance energy storage electrode materials are emerging demand in near future for the construction of supercapacitor with high energy and power densities. Herein, Nickel (II) Diethyldithiocarbamate was used as single-source precursor for Nickel Sulfide (Ni₉S₈) two-dimensional (2D) nanosheets (NSs) preparation and hexadecylamine as shape directing agent via simple solvothermal method. The orthorhombic structure of Ni₉S₈ NSs was confirmed by X-ray diffraction (XRD) pattern. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images revealed that as-prepared Ni₉S₈ nanoparticles possess sheet-like morphology. Besides, the thermal stability of Ni(DTC)₂ complex was studied by Thermogravimetric/Derivative Thermogravimetric (TG/DTG) with differential scanning calorimetric (DSC) analysis. The electrochemical properties of Ni₉S₈ NSs was studied using galvanostatic charge–discharge (GCD) and cyclic voltammetry (CV) techniques. From the charge–discharge study of Ni₉S₈ NSs, a high specific capacitance of 281 Fg^?1 was obtained at a current density of 1 Ag^?1 and up to 82% retentivity was achieved after 5000 cycles. Thus, the prepared Ni₉S₈ NSs could be the one of the attractive potential active electrode materials for the application of supercapacitor.

     

Microwave combustion synthesis,magneto-optical and electrochemical properties of NiMoO4 nanoparticles for supercapacitor application

Nickel molybdate (NiMoO₄) nanoparticles (NPs) were synthesized by a simplistic one-pot microwave combustion method using urea as the fuel. The produced NPs have been examined by powder X-ray diffraction (XRD), Fourier transform infrared (FT-IR) analysis, scanning electron microscope (SEM), energy dispersive X-ray (EDX), high-resolution transmission electron microscopy (HR-TEM) analysis. Further, optical and electronic properties were determined by UV-Visible and Photoluminescence (PL) analysis, respectively. The magnetic performance of the NiMoO₄ NPs was investigated by vibrating sample magnetometer (VSM) and the surface chemical composition was identified by X-ray photoelectron spectroscopy (XPS). The electrochemical activities of the NiMoO₄ NPs were studied by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and galvanostatic charge/discharge (GCD) analysis. From the results, the CV curves indicated the occurrence of redox couples and besides with the EIS data (Nyquist plot), confirmed the supercapacitor nature of the synthesized NiMoO₄. The prepared NiMoO₄ exhibits a high specific capacitance and rateability. This electrode grants a high specific capacitance of 450?F?g^?1 at 2?mA?cm^?2 and the well permanency with a cycling proficiency of 94% after 1000 cycles. These results clearly showed that the synthesized NiMoO₄ NPs have potential application for the forthcoming flexible and lightweight energy storage.     

Electrochemical and magneto-optical properties of cobalt molybdate nano-catalyst as high-performance supercapacitor

Nanorod shaped cobalt molybdate (CoMoO₄) electro-catalysts synthesized by microwave combustion route using urea as the fuel. The formation of monoclinic nanocrystalline structure, metal-oxygen (M–O) and chemical bonding was confirmed by X-ray powder diffractometry (XRD), Fourier transform infrared (FT-IR) and Raman spectroscopy, respectively. Scanning electron microscope (SEM) associated with energy dispersive X-ray (EDX) and high-resolution transmission electron microscope (HR-TEM) were used to confirm the morphology, elemental composition and particle size of the samples, respectively. The optical and defects were confirmed by the UV–vis. absorption and photoluminescence (PL) spectroscopy at room temperature (RT). The room temperature magnetic behaviors of product were investigated by vibrating sample magnetometer (VSM). Surface binding energy and element confirmation were examined by X-ray Photoelectron spectroscopy (XPS). The electrochemical (EC) performance was studied by cyclic voltammetry (CV), galvanostatic charge-discharge analysis (GCD) and electrochemical impedance spectroscopy (EIS) analysis. The CV curve proved the existence of redox pairs and the supercapacitor nature exhibited by the EIS (Nyquist plots). The GCD studies provided the non-symmetrical discharge curves and the highest specific capacitance (Csp) of ~ 133?F/g were acquired at a constant discharge current density (1?mA/cm^?2). The cyclic stability investigations revealed capacitance retention of about 100% after 1000 cycles, proposing the prospective usage of CoMoO₄ in energy-storage devices.     

Investigation of electrochemical behaviour and annealing effect on zinc cobaltite nanoparticles as working electrode material for energy storage device

Journal of Materials Science: Materials in Electronics - Spherical-shaped zinc cobaltite (ZnCo2O4) nanostructures have been formed by a simple sol–gel method using citric acid as a chelating...     

Flow-rate-insensitive deterministic particle sorting using a combination of travelling and standing surface acoustic waves

Manipulation of cells by acoustic forces in a continuous flow offers a means to sort on the basis of physical properties in a contactless, label-free and biocompatible manner. Many acoustic sorting systems rely on either standing waves or travelling waves alone and require specific exposure times to the acoustic field, fine-tuned by manipulating the bulk flow rate. In this work, we demonstrate a flow-rate-insensitive device for continuous particle sorting by employing a pressure field that utilises both travelling and standing acoustic wave components, whose non-uniform spatial distribution arises from the attenuation of a leaky surface acoustic wave. We show that in parts of the pressure field in which the travelling wave component dominates, particles migrate across multiple wavelengths. In doing so, they drift into areas of standing wave dominance, whereby particles are confined within their respective nodal positions. It is demonstrated that this final confinement location is dependent on the particle size and independent of the force field exposure time and thus the flow rate, permitting the continuous separation of 5.1-, 6.1- and 7.0-µm particles. Omitting the need to precisely control the bulk flow rate potentially enables sorting in systems in which flow is not driven by external pumps.