Non-blind Arnold scrambled hybrid image watermarking in YCbCr color space

Microsystem Technologies - Due to fast technological development, human beings generally depend upon computer and other digital equipments in different areas of concern/applications. Therefore,...     

A new approach for simplification and control of linear time invariant systems

Microsystem Technologies - This study presents a new approach for system simplification and control. This approach is based on the behaviour of growth and reproduction of weed plants namely...     

Estimation of power density in IMPATT using different materials

ABSTRACT

The RF output power dissipated per unit area is calculated using Runge-Kutta method for the high-moderate-moderate-high (n⁺-n-p-p⁺) doping profile of double drift region (DDR)-based impact avalanche transit time (IMPATT) diode by taking different substrate at Ka band. Those substrates are silicon, gallium arsenide, germanium, wurtzite gallium nitride, indium phosphide and 4H-silicon carbide. A comparative study regarding power dissipation ability by the IMPATT using different material is being presented thereby modelling the DDR IMPATT diode in a one-dimensional structure. The IMPATT based on 4H-SiC element has highest power density in the order of 10¹⁰ Wm^?2 and the Si-based counterpart has lowest power density of order 10⁶ Wm^?2 throughout the Ka band. So, 4H-SiC-based IMPATT should be preferable over others for the power density preference based application. This result will be helpful to estimate the power density of the IMPATT for any doping profile and to select the proper element for the optimum design of the IMPATT as far as power density is concerned in the Ka band. Also, we have focused on variation of power density with different junction temperatures and modelled the heat sink with analysis of thermal resistances.     

Development of docetaxel nanocapsules for improving in vitro cytotoxicity and cellular uptake in MCF-7 cells

The aim of this study was to fabricate docetaxel loaded nanocapsules (DTX-NCs) with a high payload using Layer-by-Layer (LbL) technique by successive coating with alternate layers of oppositely charged polyelectrolytes. Developed nanocapsules (NCs) were characterized in terms of morphology, particle size distribution, zeta potential (ζ-potential), entrapment efficiency and in vitro release. The morphological characteristics of the NCs were assessed using transmission electron microscopy (TEM) that revealed coating of polyelectrolytes around the surface of particles. The developed NCs successfully attained a submicron particle size while the ζ-potential of optimized NCs alternated between (+) 34.64?±?1.5 mV to (?) 33.25?±?2.1 mV with each coating step. The non-hemolytic potential of the NCs indicated the suitability of the developed formulation for intravenous administration. A comparative study indicated that the cytotoxicity of positively charged NCs (F4) was significant higher (p?in vitro on MCF-7 cells. Furthermore, cell uptake studies evidenced a higher uptake of positive NCs (≥1.2 fold) in comparison to negative NCs. In conclusion, formulated NCs are an ideal vehicle for passive targeting of drugs to tumor cells that may result in improved efficacy and reduced toxicity of encapsulated drug moiety.     

Theoretical Prediction of Chiral 3D Hybrid Organic–Inorganic Perovskites

Hybrid organic–inorganic perovskites (HOIPs), in particular 3D HOIPs, have demonstrated remarkable properties, including ultralong charge‐carrier diffusion lengths, high dielectric constants, low trap densities, tunable absorption and emission wavelengths, strong spin–orbit coupling, and large Rashba splitting. These superior properties have generated intensive research interest in HOIPs for high‐performance optoelectronics and spintronics. Here, 3D hybrid organic–inorganic perovskites that implant chirality through introducing the chiral methylammonium cation are demonstrated. Based on structural optimization, phonon spectra, formation energy, and ab initio molecular dynamics simulations, it is found that the chirality of the chiral cations can be successfully transferred to the framework of 3D HOIPs, and the resulting 3D chiral HOIPs are both kinetically and thermodynamically stable. Combining chirality with the impressive optical, electrical, and spintronic properties of 3D perovskites, 3D chiral perovskites is of great interest in the fields of piezoelectricity, pyroelectricity, ferroelectricity, topological quantum engineering, circularly polarized optoelectronics, and spintronics.     

Micro-irrigation development in India: an analysis of distributional pattern and potential correlates

ABSTRACT

In India, of late, micro-irrigation has received considerable policy focus. However, as of 2017, only about 10% of the potential area is under micro-irrigation. The present study analyzes the pattern and equity issues of distribution of micro-irrigation in India and identifies the potential correlates. The regression analysis reveals that the stage of groundwater development and agro-climatic differences significantly influence the spread of micro-irrigation. The relatively low spread of micro-irrigation in states with over-exploited groundwater needs attention. Overall, the study points to the need to revamp the current micro-irrigation development programmes, which focus excessively on subsidy.     

Static and dynamic corrosion behavior of SnO2-doped AZS slip cast refractory in SLS glass

The corrosion behavior of a tin IV oxide-doped AZS-refractory, subject to static and dynamic corrosion testing at 1370˚C in soda-lime-silica glass, was studied considering the effect of the microstructural features on corrosion. The refractory was synthesized by slip cast methods through reaction sintering of alumina and zircon raw materials using SnO₂ as a sintering agent. SnO₂ had a considerable influence in the enhanced alumina/zircon reaction sintering and the subsequently evolved microstructures of an interlocked Zr_(1-x)Sn_(x)O₂ solid solution reinforced alumina-mullite composite. The process kinetics of the refractory corrosion followed reasonably well the predicted dependence on the square root of angular velocity under forced convection corrosion. Glass chemical corrosion and erosion of the refractory, under static and dynamic glass conditions, respectively, revealed the Zr_(1-x)Sn_(x)O₂ solid solution-rich mullite matrix as providing the most corrosion resistance and glass compatibility.     

Fuel cells for non-automotive uses: Status and prospects

Fuel cells are in varying stages of commercialization for both automotive and non-automotive applications. The fuel cell industry has made substantial progress but still needs to reduce costs and improve performance to compete successfully with established technologies. In just 5 years, costs have been reduced by a factor of two while improving efficiency and durability. Based on interviews with fuel cell manufacturers in the U.S., Japan and the EU and information from published sources, a model of non-automotive fuel cell markets is constructed and used to estimate the impacts of government policies and to project the potential evolution of the industry to 2025. The model includes the effects of learning-by-doing, scale economies and exogenous technological progress on component and system costs, estimates customer choices between fuel cell and competing established technologies, and attempts to measure the impacts of government policies. With continued policy support it appears likely that the industry can become self-sustaining within the next decade.