An extremely fast adaptive high-performance filter to remove salt and pepper noise using overlapping medians in images

A new fast adaptive high-performance filter (FAHPF) has been proposed to remove salt-and-pepper noise in images. ‘Maximize the speed without compromising denoising performance’ is the fundamental intention to build up the FAHPF algorithm. Among diverse phases of filtering employed in the FAHPF, overlapping medians (OM) is our newly proposed frame-based filtering concept which is the basis for speed of FAHPF and running averages embedded with OM is an idea behind excellent denoising performance of FAHPF at the same pace. Simulation experiments have been conducted and denoising results of FAHPF has been investigated against very recently developed filtering methods. It is proved that the FAHPF excellently outperforms many of state-of-the-art filters considered for comparison, in terms of peak signal to noise ratio, structural similarity index, and visual representation and requires the extremely shortest execution time among all, which could make it as a real time filter.     

Phase Transformation Introduced by Mechanical and Chemical Surface Preparations of Tetragonal Zirconia Polycrystals

Cutting of Y₂O₃-doped TZP rods by a low-speed diamond saw introduces an unidentified, metastable phase X (x -ZrO₂) coexisting with the tetragonal ( t -ZrO₂) and the monoclinic ( m -ZrO₂) phases initially present in the sample. Further mechanical deformation of the cut surface by indentation or polishing sustains the x -ZrO₂. Chemical etching removes the x -ZrO₂ and increases the m -ZrO₂content.     

Analysis of blood and tissue in gallbladder cancer

Particle induced X-ray emission, particle induced γ-ray emission studies has been carried out to analyse normal and carcinoma tissues and blood samples of gallbladder of both sexes and seventeen trace elements namely Na, Mg, Al, K, Ca, Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Br and Pb were estimated in the tissue and blood samples. In the present study, concentration of Zn in the carcinoma gallbladder tissue is less than that of the normal gallbladder tissue. Tobacco habit could be one of the important factors to decrease the elemental concentrations in blood and tissue samples.     

Exploitation of microbial antagonists for the control of postharvest diseases of fruits: a review

Fungal diseases result in significant losses of fruits and vegetables during handling, transportation and storage. At present, post-production fungal spoilage is predominantly controlled by using synthetic fungicides. Under the global climate change scenario and with the need for sustainable agriculture, biological control methods of fungal diseases, using antagonistic microorganisms, are emerging as ecofriendly alternatives to the use of fungicides. The potential of microbial antagonists, isolated from a diversity of natural habitats, for postharvest disease suppression has been investigated. Postharvest biocontrol systems involve tripartite interaction between microbial antagonists, the pathogen and the host, affected by environmental conditions. Several modes for fungistatic activities of microbial antagonists have been suggested, including competition for nutrients and space, mycoparasitism, secretion of antifungal antibiotics and volatile metabolites and induction of host resistance. Postharvest application of microbial antagonists is more successful for efficient disease control in comparison to pre-harvest application. Attempts have also been made to improve the overall efficacy of antagonists by combining them with different physical and chemical substances and methods. Globally, many microbe-based biocontrol products have been developed and registered for commercial use. The present review provides a brief overview on the use of microbial antagonists as postharvest biocontrol agents and summarises information on their isolation, mechanisms of action, application methods, efficacy enhancement, product formulation and commercialisation.     

Concept of a miniature optical spectrometer using integrated optical and micro-optical components

We describe the concept of a super compact diffractive imaging spectrometer, with optical components a few millimeters across in all dimensions, capable of detecting optical fluorescence spectra within the entire visible spectral range from 400 nm to 700 nm with resolution of the order of 2 nm. In addition, the proposed spectrometer is capable of working simultaneously with multiple, up to 35, independent input optical channels. A specially designed diffractive optical element integrated with a planar optical waveguide is the key component of the proposed device. In the preliminary experimental tests, a uniform waveguide grating with a microlens was used to mimic operation of the diffractive optical element. A microspectrometer with optical components measured below 1 cm in all dimensions covers the spectral range from 450 nm to 650 nm and shows a spectral resolution of 0.5 nm at wavelengths close to 514 nm and 633 nm.     

Biomass carbon & its prospects in electrochemical energy systems

Activated carbon has now become a vital active material in multifarious applications such as catalytic supports, removal of pollutants, battery electrodes, capacitors, gas storage etc., and these applications require carbon powders with desirable functionalities like surface area, chemical constituents and pore structure. Hence the production of activated carbon materials, especially from cheap and natural bio-precursors (biomass) is a highly attractive research theme in today's science of advanced materials. Though abundant and detailed reports on activated carbons for these applications are available in the literature, creating a consolidated account on the biomass derived activated carbon would serve as a database for the researchers and thus appears justified. Hence an overview on activated carbons (preparation, physical and electrochemical properties) derived especially from biomass for the specific application as electrodes in electrochemical energy devices has been presented to stress the importance of biomass, bioenergy and conversion of wastes into energy concept further. It is certain from the survey of around 100 recent published articles that the biomass carbons have outstanding capability of being applied as electrodes in the energy devices. Particularly, carbon (unactivated) derived from pyrolized peanut shells exhibited a maximum specific capacity of 4765 mAhg⁻¹ in the case of lithium-ion batteries and coconut shell derived carbon in KOH electrolyte gave capacitance of 368 Fg⁻¹ and ZnCl₂ activated carbon from waste coffee grounds exhibited 368 Fg⁻¹ in H₂SO₄. Undoubtedly the study indicates that the biomass derived carbons have economic and commercial promise in the near future.     

Effect of thermal aging on the crystal structural characteristics of poly(tetra fluoro ethylene)

The residual effects of cumulative thermal aging on the crystal structural characteristics of the fluoro carbon poly(tetra fluoro ethylene) (PTFE) have been studied by X‐ray diffraction methods. The initial hexagonal arrangement of the PTFE chains in a 15₇ helical conformation is left unaffected by the exposures to temperatures (T), up to and beyond its melting point, T_m. The unit cell registers a residual anisotropic volume expansion. The anisotropy arises from the enhanced enlargement of the basal plane dimension a compared with the axial dimension c. Conformational changes contributing to the observed increase in the chain length have been examined. Enhancement of residual crystallinity of samples aged at T's < T_m suggests that the selective thermal aging could be used as an effective tool to improve the initial crystallinity of commercially available PTFE. The activation energy for 50% enhancement in initial crystallinity has been estimated as 53.9 kJ mol^?1. Aging at 400°C, a temperature above T_m, is accompanied by markedly different features viz., deterioration in crystallinity and other structural characteristics. The overall behavior of thermally aged PTFE bears a marked similarity to many polyamides. POLYM. ENG. SCI., 47:1724–1729, 2007. © 2007 Society of Plastics Engineers     

Low Cost Porous Alumina with Tailored Microstructure and Thermal Conductivity Prepared using Rice Husk and Sucrose

This study demonstrates a cost‐effective way to fabricate porous ceramics with tailored porosity and pore microstructure using 5–40 wt% rice husk (RH) in <75 μm, 75–180 μm, 180–355 μm, 355–420 μm, and 420–600 μm size, as pore former. Sucrose, used as binder, also acted as a pore former. Porous alumina compacts with 20%–66% volume fraction porosity and 50–516 μm pore size (length) were successfully fabricated. Microstructure of samples reveal randomly oriented elongated coarse pores and fine pores (avg. size 4 μm), created during burnout of RH and sucrose, respectively. Samples with isolated and/or interconnected pores were fabricated using this process. Thermal conductivity of the samples prepared was measured using Transient Plane Source (TPS) technique. Thermal conductivity ranges from 1.2 to 24 W/mK. Experimental results agree closely with predictions made based on Effective Medium Theory (EMT) for a two‐phase system.