Hybrid robust watermarking for color images

In this paper, we present a blind and highly robust watermarking scheme method for color images by combining the advantages of both spatial and frequency domain. Watermark is generated for each channel (RGB) of the color image by extracting spatial domain features using Gray Level Co-occurence Matrix as well as a unique identification number. The watermark is embedded in Principal Component Analysis (PCA)-based less correlated low and high frequency sub bands in such a way that the perceptual quality of the image is preserved. Imperceptibility is achieved by embedding the watermark in less correlated sub bands and robustness is achieved by spreading the watermark using Laplacian Pyramid in contourlet transform. Simulation results show that the proposed scheme can survive various image processing and signal processing attacks. The proposed method achieves high transparency, imperceptibility and robustness compared to some of the existing schemes.     

Identification of the Sex Pheromone of Holotrichia reynaudi

The male attractant pheromone of the scarab beetle Holotrichia reynaudi, an agricultural pest native to southern India, was extracted from abdominal glands of females with hexane and analyzed by gas chromatography–mass spectrometry. Field testing of the candidate chemicals, indole, phenol, and anisole, both alone and as binary mixtures, led us to conclude that anisole was the major component of the sex pheromone. Neither male nor female beetles were attracted to indole or phenol on their own. Similarly, when indole and anisole were combined, the attractiveness of the solution did not increase over that obtained with anisole alone. However, combination of phenol and anisole did alter the attractiveness of anisole, with fewer male beetles attracted to the binary mixture than to anisole on its own. The behavior of female beetles was not altered by any of the chemicals tested. Anisole is also the sex pheromone of H. consanguinea, making this the first known example of two melolonthine scarabs sharing the same pheromone.     

Electrical properties of nitric acid and DMSO treated PEDOT:PSS/n-Si hybrid heterostructures for optoelectronic applications

Organic/inorganic heterostructures are an emerging and interesting field of research for optoelectronics. In this work, an efficient organic/inorganic hybrid heterojunction between PEDOT:PSS and n-type Silicon has been fabricated for optoelectronic applications. Samples with varying thickness of PEDOT:PSS were prepared by spin coating technique and the electrical conductivity of organic layers was modified using DMSO as additive. Post fabrication, the hybrid heterostructures were treated with HNO₃ vapor so as to enhance the conductivity of the organic layer. Surface treatment with HNO₃ was found to lower the roughness of the organic layer and enhance the transparency of the layer. I–V characteristics reveal optimized behavior of HNO₃ treated PEDOT:PSS layer with a low Ideality factor (n~3.2) and a barrier height (Φ_B) of 0.8 eV. The findings of the study provide a promising efficient method to enhance the electrical and device properties of PEDOT:PSS/n-Si heterostructures for optoelectronic applications. © 2020 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48952.     

Activated carbon from grass – A green alternative catalyst support for water electrolysis

Grass blades (turf grass) have been selected as a cheap biomass source of producing activated carbon for supporting Pt particles for utilizing as electrocatalyst for H₂ generation through electrolysis of water. Activation is done using ZnCl₂ followed by thermal processing at 250 °C. 1% Pt was supported over the grass derived activated biomass carbon (G-ABC) powder to result in Pt@G-ABC. After physical characterization, Pt@G-ABC sample has been tested for its catalytic activity in 1 M sulfuric acid solution for H₂ gas generation through Linear Sweep & Cyclic Voltammetry. Cost factor involved in the production of G-ABC has also been compared with the traditional commercially available carbon support. The studies suggest that grass may be considered not only as a potential alternative source for producing carbon supported catalyst for H₂ generation but also highlight the production of low-cost carbon for further applications like electrode materials, adsorbent for color, odor and hazardous pollutants.     

N‐Heterocyclic Carbene‐Catalyzed Oxidative Amidation of Aldehydes with Amines

The N‐heterocyclic carbene (NHC)‐catalyzed oxidative amidation of aromatic aldehydes with amines in the presence of N‐bromosuccinimide (NBS) as an oxidant has been developed for the synthesis of amides. This amidation strategy is tolerant to both the electronic and the steric nature of the aryl aldehydes employed. The present methodology was extended to chiral amino acid derivatives to generate the corresponding amides in good yields and excellent ee values (>98%).

     

Development of fly ash cenosphere-based composite for thermal insulation application

Cenosphere-based composite was developed with addition of clay and other additives, by dry processing route. The performance of cenosphere as high-temperature insulating material was studied. Cenosphere stands unique among the constituents found in fly ash due to its hollow spherical structure. Cenosphere is utilized in numerous modern applications due to its unique properties such as lightness, high compressive strength, enhanced flow characteristics, less water absorption, chemical inertness, and good thermal resistance. Keeping cenosphere as major component, three different mix recipes for insulating brick were made. The recipes were blended and shaped by pressing, followed by drying and sintering at 1000°C. The prepared samples were analyzed for their physical, mechanical, and thermal properties. The surface and pore distribution are analyzed by scanning electron microscope. Results from the analysis shows that cenosphere can be used as high temperature insulating material.     

Artificial neural network simulation of rare earths solvent extraction equilibrium data

Separation of high purity rare earth elements from their mixed oxides, obtained from monazite or xenotime, requires multiple stages of separation by circuits incorporating one or more solvents. The separation factors being small, a large number of counter-current stages become necessary. Process development, analysis, optimization and control of rare earths are a complex task. Computer simulation provides useful tools in this area. Application of artificial neural networks (ANN) for simulation of equilibrium data in solvent extraction of rare earths is described in this paper. The back propagation ANN model has been used. The input neurons correspond to the system state variables such as equilibrium concentration and acidity. The partitioning of the metal ion into the two immiscible phases involved in solvent extraction is measured in terms of distribution ratio D. The model predicts the D value under varying process conditions. Comparison of ANN with conventional models shows that ANN is superior. The average absolute error for ANN model is one-fourth that of the conventional models. The approach has been used, in conjunction with a process simulation model, successfully for industrial process development involving production of high purity neodymium.     

Ontology Based Ocean Knowledge Representation for Semantic Information Retrieval

The drastic growth of coastal observation sensors results in copious data that provide weather information. The intricacies in sensor-generated big data are heterogeneity and interpretation, driving high-end Information Retrieval (IR) systems. The Semantic Web (SW) can solve this issue by integrating data into a single platform for information exchange and knowledge retrieval. This paper focuses on exploiting the SW base system to provide interoperability through ontologies by combining the data concepts with ontology classes. This paper presents a 4-phase weather data model: data processing, ontology creation, SW processing, and query engine. The developed Oceanographic Weather Ontology helps to enhance data analysis, discovery, IR, and decision making. In addition to that, it also evaluates the developed ontology with other state-of-the-art ontologies. The proposed ontology’s quality has improved by 39.28% in terms of completeness, and structural complexity has decreased by 45.29%, 11% and 37.7% in Precision and Accuracy. Indian Meteorological Satellite INSAT-3D’s ocean data is a typical example of testing the proposed model. The experimental result shows the effectiveness of the proposed data model and its advantages in machine understanding and IR.     

Stability and Sensitivity Enhanced Electrochemical In Vivo Superoxide Microbiosensor Based on Covalently Co-immobilized Lipid and Cytochrome c

Enhanced stability and sensitivity of a superoxide anion radical (O(2)(?-)) microbiosensor were achieved through the sequential immobilization of lipid and cytochrome c (Cyt c) covalently bonded onto a conducting polymer layer that showed a clear quasi-reversible direct electron transfer (DET) process. The formal potential and the apparent standard rate constant were determined to be -0.24 V and 0.62 ± 0.05 s(-1), respectively. The detection of O(2)(?-) was attained through the catalytic activity of the haem group of Cyt c stabilized by coimmobilized lipid molecules (1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine-n-dodecanylamine (DGPD)). The linear dynamic range and the detection limit of the O(2)(?-) analysis were determined to be 0.2-6.0 nM and 30.0 ± 0.9 pM, respectively. The in vivo microbiosensor implanted into rat brain successfully determined the extracellular level of O(2)(?-) produced by acute and repeated injections of cocaine. The present O(2)(?-) microbiosensor could be an effective tool for monitoring the change in extracellular O(2)(?-) levels in response to stimulant drug exposure.     

Transport of methyl methacrylate monomer through natural rubber

The diffusion and transport of inhibitor-free methyl methacrylate monomer through crosslinked natural rubber (NR) have been studied at different temperatures. NR has been vulcanised by conventional, efficient and peroxide vulcanisation technique. ESR spin probe spectroscopy was used to study the flexibility of NR network chains at different temperatures. The dependence of diffusion coefficient on the nature of crosslinks and temperature has been studied. The intrinsic diffusion coefficient was found to increase with increase of temperature. The interaction parameter, permeability, sorption coefficient and molecular weight between crosslinks have been evaluated using diffusion data. The morphology of the swollen network and thermodynamic parameters has been determined using diffusion data. The efficient and peroxide system showed the least uptake and the conventional system showed the highest uptake. This study also proved that same extent of crosslinking can be achieved for different vulcanising systems by curing the samples to a common rheometric torque. The theoretical modelling shows Fickian mode of diffusion with a slight deviation.