Hybrid Common Control Channel Based MAC Protocol with Proactive Handoff Scheme in Cognitive Radio Network

Wireless Personal Communications - The common control channel (CCC) design plays a pivotal role in achieving the desired quality of service in cognitive radio (CR) technology. Various schemes of...     

Understanding the effect of milk composition and milking season on quality characteristics of chhana

The quality characteristics of chhana varied due to the milk composition (cow‐, buffalo‐, and mixed‐ milk) which in turn was affected by the milking season (summer and winter). Upon heating and acidification of milk samples water holding phenomena and denatured protein association within and with other components lead to variation in both macroscale properties (color, texture, and rheology) and molecular bonding patterns (FTIR character). Yield, lightness (L* value), textural firmness, and elastic modulus of chhana increased with increasing proportion of buffalo milk in mixed milk due to higher total solids and less moisture content in both the seasons. Total protein, fat, water, and interaction between them and extent of hydrogen bonding significantly affected the rheological and textural properties of chhana samples.     

Affect representation and recognition in 3D continuous valence–arousal–dominance space

Multimedia Tools and Applications - Currently, the focus of research on human affect recognition has shifted from six basic emotions to complex affect recognition in continuous two or three...     

Chemo‐enzymatic synthesis of lipophilic ferulates and their evaluation for antioxidant and antimicrobial activities

An efficient chemo‐enzymatic synthesis of ferulic acid‐based structured lipids mimicking triacylglycerol with a pendant phenolic moiety was carried out for the first time. Initially, ferulic acid was reduced to coniferyl alcohol, followed by its esterification with fatty acids. The key step in the synthesis was dihydroxylation of the olefinic side chain of coniferyl ester, which was eventually esterified with fatty acids to generate phenolic structured lipids. Two such compounds of varying fatty acid chain lengths were synthesized in good yield. Structural confirmation of both compounds is based on IR, ¹H and ¹³C NMR, and MS techniques. The synthesized compounds were tested for in vitro antioxidant and antimicrobial activities. Both compounds exhibited moderate to good antioxidant activity. The phenolic structured lipid with only shorter‐chain fatty acids showed antibacterial activity. Both compounds did not show any antifungal activity.     

Silver-Modified CrO2 of Core–Shell Nanoparticles and their Magnetic and Impedance Properties

A chemical CrO₃→CrO₂ transformation reaction occurs in the presence of Ag⁺ species forming CrO₂ core–shell magnetic nanoparticles. The process involves heating CrO₃ with AgNO₃ in an aqueous solution in ambient air at a low temperature of 330–350 K. Shell thickness (diamagnetic amorphous silver) is controlled to be ∼2 nm tunable to the magnetic and impedance properties. Improved coercivity H _c=75.7 mT and the Curie temperature T _C=415 K are found with saturation magnetization M _s = 80 Am²/kg after annealing the sample at 573 K in air for 2 h. On heating, the impedance (or electrical resistance) varies steadily through a maximum in the T _C point in a typical half-metallic ceramic behavior. In a dynamic response to frequency f , the T _C increases from 418 K at 1 kHz to as high a value as 505 K at 1 MHz. A nearly f independent and low value of dissipation factor φ as 0.05 is promising for low power loss high-frequency applications of such CrO₂ particles.     

Crystallization of acicular platelet particles of W-type hexagonal strontium ferrite for magnetic recording applications

Acicular platelets of the W-type hexagonal strontium ferrite (SrFe₁₈O₂₇) have been crystallized from the borate glass system with the aid of 1 mol% SiO₂ and Bi₂O₃. It was found that particle size and morphology of the system can be effectively altered by proper use of the additives and the thermal treatment of the samples. Addition of SiO₂ induces growth of ferrite as fine grains (average size 0.1m), while Bi₂O₃ with the acicular-shaped particles (which are platelets) with an aspect ratio of 10 are formed. The system also exhibits a relatively sharp particle size distribution compared to that for the samples containing no additive. Detailed magnetic and microstructural measurements of all the useful samples were carried out to characterize them for applications in magnetic recording devices.Visiting Scientist.