Compact fractal based UWB mimo antenna with dual band dispensation

Analog Integrated Circuits and Signal Processing - In this study, a fractal-based ultra-wideband multiple-input-multiple-output antenna with a compact structure is proposed. By using monopole...     

Synthesis,characterization, and thermal properties of cyanate esters with azo linkages

A series of azo functionalized diols were synthesized through diazotization which involves the reaction of amine with phenol and 2,6‐dimethyl phenol. Four different amines have been used to prepare five bisphenols. These bisphenols were converted to their corresponding cyanate esters by treatment with cyanogen bromide (BrCN) in the presence of triethylamine (Et₃N). The chemical structures of the prepared compounds were characterized with Fourier Transform Infrared, ¹H‐NMR, ¹³C‐NMR spectroscopy, and elemental analysis. Dynamic curing behavior was investigated using differential scanning calorimetry. The maximum curing temperature of these cyanate esters are in the range of (186–208°C). T_g values of the polycyanurate networks are in the range of 245–276°C. The thermal properties of cured cyanate ester were studied at a heating rate of 10°C min^?1 in N₂ atmosphere. The polymers showed excellent thermal stability (T₁₀ was found to be in the range 405–438°C) and the percentage of char yield at 800°C were found to be 30–49. The flame retardancy of the cyanate ester resins have been studied using limited oxygen index value which is in the range of 29.5–37.1 at 800°C. POLYM. ENG. SCI., 55:47–53, 2015. © 2014 Society of Plastics Engineers     

Sonochemically Prepared GdWNFs/CNFs Nanocomposite as an Electrode Material for the Electrochemical Detection of Antibiotic Drug in Water Bodies

The work demonstrates the development of an electrochemical sensor for quantification of Chloramphenicol (CA) using pencil graphite electrode (PGE) modified with Gadolinium tungstate nano flakes and carbon nano fibers composite (PGE/GWNfs/CNFs). The composite was further characterized and confirmed by X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy, transmission electron microscopy analysis. The prepared GWNfs/CNFs nano composite was fabricated by drop casting method to get PGE/GWNfs/CNFs working electrode. The modified electrode is then analyzed by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and differential pulse voltammetry (DPV) methods for its electrochemical and electrocatalytic property. The electrochemical investigation of developed sensor shows enhanced activity towards electro-oxidation of CA. The DPV studies revealed high efficacy characteristics such as sensitivity in the range 0.03984 µA µM^?1 cm^?2, selectivity, good linear range (5–50 μM), and low detection limit (0.4 μM). The study benchmarks the use of GWNfs/CNFs as an excellent transducer material in electrochemical sensing of CA in standard samples thus, it finds an efficient potential application in the analysis of CA in environment sample analysis.

     

Green-Inspired Fabrication of Silver Nanoparticles and Examine its Potential In-Vitro Cytotoxic and Antibacterial Activities

Journal of Inorganic and Organometallic Polymers and Materials - The present work demonstrates the non-hazardous and environmentally benevolent green fabrication of silver nanoparticles using...     

A study on the effect of bulk water content and drying temperature on the colour of dyed cotton fabrics

In the present study, the effect of various levels of bulk and free water content and its distribution on the colour of cotton fabrics dyed with direct dyes and their combinations were analysed. Twill and plain structures with two different parameters of fabric construction were chosen. The dyed samples were adjusted to different levels of wet pick‐up, with water ranging from 50% to 125% on the bone dry weight of the fabric (odwf) to achieve various levels of bulk water content. Further, the residual moisture content of the samples was adjusted to 40–10% odwf by means of hot air drying at different temperatures to obtain different levels of free water content and its distribution. For the assessment of colour and its comparison, the parameters ΣK/S and values were used. In order to bring out the true effect of moisture distribution and fabric structure, normalisation of dye uptake in the fabric based on weight and area were considered, respectively. The plain structures show a higher increase in colour than the twill structures when the bulk water content increases. At the same time, the fabric structures do not play a significant role, with increase in colour attributable to change in drying temperature. The findings reveal that the bulk water content, drying temperature and fabric geometry affects the colour of the fabric significantly.     

Raman,photoluminescence analysis on Cu(InAl)Se2 thin films and the fabrication of Cu(InAl)Se2 based thin film solar cells

Cu(InAl)Se₂ (CIAS) thin films have been prepared by chemical bath deposition technique. Thickness of the prepared films has been measured by gravimetric technique. The structure, composition and optical transition as well as bandgap have been estimated by X-ray diffraction, energy dispersive X-ray analysis and spectrophotometer analysis. Raman analysis has been made on the prepared CIAS thin films to assign the fundamental lattice mode and to confirm the films crystallinity and stoichiometry. PL analysis has been carried out to find the effective mass of holes and electron, dielectric constant, the involved defects and their activation energy. Cu(InAl)Se₂-based solar cells with different types of buffer layers such as CdS, CdS:Cu, CdS:In were fabricated. The current and voltage were measured using an optical power meter and an electrometer and the fabricated solar cells were illuminated using 100 mW/cm² white light under AM1 conditions.     

Synthesis and characterization of poly (amide-imide-imide)s based on diacids with bulky m-chloro phenyl moiety and rigid pyridine moiety

A series of novel aromatic diamines containing kinked m-chloro phenyl moiety was synthesized by the reaction of m-chloro benzaldehyde with 2,6-dimethyl aniline. The tetraimide diacid was synthesized by using the prepared diamine with benzophenone tetracarboxylic acid dianhydride (BPTDA) and p-amino benzoic acid. The polymers were prepared by treating the tetraimide diacid with different aromatic diamines. The structures of the monomers and polymers were identified by ¹H-NMR, FTIR,¹³C-NMR and elemental analysis. The polymers showed excellent thermal stability, solubility and mechanical properties. Their structure–property relationship was studied by comparing these m-chloro polymers with polymers containing rigid Pyridine moiety.     

Real-time grasping strategies using event camera

Journal of Intelligent Manufacturing - Robotic vision plays a key role for perceiving the environment in grasping applications. However, the conventional framed-based robotic vision, suffering from...     

In situ growth of Prussian blue nanocubes on polypyrrole nanoparticles: facile synthesis,characterization and their application as fiber optic gas sensor

Polypyrrole (PPy) and polypyrrole/Prussian blue (PPy–PB) nanocomposite-based fiber optic gas sensors are developed for gas sensing application. Prussian blue (PB) nanocubes are successfully grown on polypyrrole (PPy) nanoparticles by in situ oxidative polymerization method to obtain PPy–PB nanocomposite. PPy and PPy–PB are evaluated based on structural, morphological and electrical properties. The characteristic peaks present in the FTIR spectra of pure PPy and PB nanoparticles are also present in the FTIR spectrum of PPy–PB nanocomposite with small shifts in the absorption maximum. The XRD pattern reveals the semicrystalline structure of PPy–PB nanocomposite with an average crystallite size of 22 nm, and the morphology (FESEM) shows the formation of PB nanocubes over PPy matrix. AC conductivity measurements show slight improvement in the conductivity value of PPy–PB in comparison with PPy. Dielectric studies in the frequency range of 50 Hz–5 MHz reveal that PPy–PB nanocomposite is a high-k dielectric material. At 50 Hz, PPy–PB exhibits high dielectric constants of 1149 and 766 with low dielectric loss values of 9.9 and 4.6 at 150 and 120 °C, respectively. Further, their application as fiber optic gas sensors in sensing various gases is studied using fiber optic technique. The spectral response is studied for various concentrations (0–500 ppm) of ammonia, acetone and ethanol gases at room temperature. The study shows that the spectral intensity increases linearly with different concentrations of all gases. The clad-modified fiber optic sensor with PPy–PB nanocomposite exhibits enhanced sensitivity for ethanol than clad-modified fiber optic sensor with PPy nanoparticles. TGA studies reveal the high thermal stability of PPy–PB nanocomposite. Hence, PPy–PB-based fiber optic sensors can be used to sense toxic ethanol vapor not only at room temperature but also in a composite environment where a temperature variation is expected.