Magnetic and Raman scattering studies of Co-doped ZnO thin films grown by pulsed laser deposition

Phase pure Zn_1?x Co _x O thin films grown by pulsed laser deposition have transmittance greater than 75 % in the visible region. Raman studies confirm the crystalline nature of Zn_1?x Co _x O thin films. Zn_0.95Co_0.05O thin films show room temperature ferromagnetism with saturation magnetization of 0.4μ _B /Co atom. The possible origin of paramagnetism at higher Co doping concentrations can be attributed to the increased nearest-neighbor antiferromagnetic interactions between Co²⁺ ions in ZnO matrix. XPS confirms the substitution of Co²⁺ ions into the ZnO host lattice.     

Highly luminescent undoped and Mn-doped ZnS nanoparticles by liquid phase pulsed laser ablation

In this paper we report the synthesis of highly luminescent ZnS and Mn-doped ZnS nanoparticles with uniform particle size distribution by liquid phase pulsed laser ablation. The formation of nanosized ZnS crystallites was confirmed by high-resolution transmission electron microscopy (HRTEM) images. The optical properties of these nanoparticles were studied by room temperature photoluminescence (PL) spectra. The PL emission from the ZnS nanoparticles shows a sharp peak in the UV region (334 nm) corresponding to the band edge and a broad peak in the visible region which can be attributed to the sulphur vacancies, cation vacancies and surface states in the nanocrystals. The yellow emission from the Mn-doped ZnS nanoparticles can be attributed to the radiative transition between ⁴T₁ and ⁶A₁ levels within the 3d⁵ orbital of Mn²⁺.     

Tracing of interference fringes using average gray value and simultaneous row and column scan

An algorithm for computer tracing of interference fringes is reported. The method uses the average gray-level value for thresholding, row and column scans for determining the type of the scan and simultaneous row and column scan for tracing. The proposed method yield good result even for low-contrast and high-noise images. The program for the interferogram tracing was written using MATLAB6.     

Relationships between molecular structure and thermomechanical properties of bio‐based thermosetting polymers

Molecular dynamics simulations are used to study highly cross‐linked epoxy networks comprised of furanyl epoxy monomer, 2,5‐bis[(2‐oxiranylmethoxy)methyl]‐furan (BOF), that is cross‐linked by two furanyl amine hardeners, 5,5'‐methylenedifurfurylamine (DFDA) and 5,5'‐ethylidenedifurfirylamine (CH₃‐DFDA). Important properties of these fully furan‐based systems, including room temperature density, glass transition temperature, and Young's modulus are found to agree with previous experimental results. We also compare the simulated and experimental values of four fully furan‐based thermosetting materials to those using the conventional resin diglycidyl ether of bisphenol A (DGEBA) cured with the two furanyl hardeners. Our simulation results predict a slight decrease in density and Young's modulus, but no impact on the glass transition temperature, upon adding the methyl group in DFDA. Detailed analyses of the MD trajectories reveal the underlying mechanisms responsible for the observed structure/property relations, which center on the lack of collinear covalent bonds in the BOF molecular structure. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017 , 55, 285–292     

An overview of innovation in industrial drying: current status and R&D needs

Over the past three decades there has been nearly exponential growth in drying R&D on a global scale. Although thermal drying had always been the workhorse of almost all major industrial sectors, the need for and opportunities in basic as well as industrial research became clear only after the energy crisis of the early 1970s. Although the price of oil did drop subsequently the awareness of the significance of improving the drying operation to save energy, improve product quality as well as reduce environmental effect remained and indeed has flourished over recent years. New drying technologies, better operational strategies and control of industrial dryers, as well as improved and more reliable scale-up methodologies have contributed to better cost-effectiveness and better quality dried products. Yet there is no universally or even widely applicable drying theory on the horizon. Most mathematical models of drying remain product-equipment specific for a variety of reasons. In this paper, we examine the role of innovation in drying in various industrial sectors, e.g. paper, wood, foods, agriculture, waste management, etc. Progress made over the past three decades and the challenges ahead are outlined. Some areas in need of further research are identified. Examples of intensification of innovation in dryer designs via mathematical modeling are discussed. Finally, the need for closer interaction between academia and industry is stressed as the key to successful drying R&D in the coming decade.     

Electrochemical studies of novel olivine-layered (LiFePO4-Li2MnO3) dual composite as an alternative cathode material for lithium-ion batteries

Journal of Solid State Electrochemistry - In the present work, olivine-layered composites, i.e., LiFePO4-Li2MnO3, are successfully synthesized in the form of a single monolithic electrode and layer...     

Development and Validation of a High-Performance Thin-Layer Chromatographic Method for the Simultaneous Estimation of Torsemide and Eplerenone by Quality by Design Approach

JPC – Journal of Planar Chromatography – Modern TLC - This paper includes the development of a novel, systematic, quality by design (QbD)-based high-performance thin-layer...     

QbD approached comparison of reaction mechanism in microwave synthesized gold nanoparticles and their superior catalytic role against hazardous nirto‐dye

Microwave irradiation (MI) process characteristically enables extremely rapid “in‐core” heating of dipoles and ions, in comparison to conventional thermal (conductance) process of heat transfer. During the process of nanoparticles synthesis, MI both modulates functionality behaviors as well as dynamic of reaction in favorable direction. So, MI providing a facile, favorable and alternative approach during nanoparticles synthesis nanoparticles with enhanced catalytic performances. Although, conventionally used reducing and capping reagents of synthetic origin, are usually environmentally hazardous and toxic for living organism. But, in absence of suitable capping agent; stability, shelf life and catalytic activity of metallic nanoparticles adversely affected. However, polymeric templates which emerged as suitable choice of agent for both reducing and capping purposes; bearing additional advantages in terms of catalyst free one step green synthesis process with high degree of biosafety and efficiency. Another aspect of current works was to understand role of process variables in growth mechanism and catalytic performances of microwave processed metallic nanoparticles, as well as comparison of these parameters with conventional heating method. However, due to poor prediction ability with previously published architect OFAT (One factor at a time) design with these nanoparticles as well as random selection of process variables with their different levels, such comparison couldn't be possible. Hence, using gum Ghatti (Anogeissus latifolia) as a model bio‐template and under simulated reaction conditions; architect of QbD design systems were integrated in microwave processed nanoparticles to establish mechanistic role these variables. Furthermore, in comparison to conventional heating; we reported well validated mathematical modeling of process variables on characteristic of nanoparticles as well as synthesized gold nanoparticles of desired and identical dimensions, in both thermal and microwave‐based processes. Interestingly, despite of identical dimension, MI processed gold nanoparticles bearing higher efficiency (kinetic rate) against remediation of hazardous nitro dye (4‐nitrophenol), into safer amino (4‐aminophenol) analogues.