Optimized unequal error protection of embedded video bitstream using adaptive-hierarchical QAM

In this paper, a reliable video communication system using adaptive Hierarchical QAM (HQAM) is designed to provide optimized unequal error protection (UEP) to embedded video bitstreams. Based on the relative importance of bits, video bitstream is partitioned into two priorities, namely High Priority (HP) and Low Priority (LP) substreams. Then, the optimal value of modulation (or hierarchical) parameter (α) of HQAM, which controls the relative error protection of these substreams, is selected from a pre-designed look-up table. The proposed system adapts itself by adapting the optimal α according to the varying channel condition, without changing the modulation level. This is in contrast to conventional WiMAX and LTE systems, in which dynamic switching among multiple modulations is used to adapt the varying channel conditions. This paper proposes HQAM with adaptive α as an alternative to the multiple modulation schemes. Moreover, for fixed average transmission power, receiver demodulates symbols without the knowledge of α. In order to further improve the video quality and to reduce the effects of erroneously received LP bits, the proposed system uses another level of adaptation, in which received LP bits are adaptively considered or discarded, before decoding the video, depending on the channel conditions (or optimized α). Simulation results show that proposed system can achieve significant improvement in the video quality compared to QAM based EEP scheme and non-adaptive HQAM.     

Scanning electron microscopic observations on micro-organisms in the root nodules of Tribulus terrestris L. (Zygophyllaceae)

Scanning electron microscopic observations were made on the micro-organisms of root nodules of Tribulus terrestris L. The results showed that nodules of T. terrestris contained dual infection consisting of Rhizobium sp. and Newmania karachiensis. Based on these observations, T. terrestris should be grouped with nonlegume Parasponia-type bacterial nodules.     

Extended temperature–entropy (T–s) diagrams for aqueous lithium bromide absorption refrigeration cycles

Temperature–entropy (T–s) diagrams have the unique capability of being able to quantify processes in terms of both the first and second laws of thermodynamics. Although use of generalised T–s diagrams has been made to indicate or represent generalised absorption cycles, with the exception for NH₃/water systems, these diagrams have not been specifically tailored to scale to quantify LiBr/water systems. The main barrier for this is that the diagram needs to represent the necessary properties of both the refrigerant (water) and of the solution (LiBr/water). This paper describes the use of the T–s diagram of water extended with additional curves to represent real and ideal LiBr/water absorption cycles. An explanation is provided on several methods available, including details of the thermodynamic justification of the method that was used, to construct the extended diagrams. Finally, the extended T–s diagram is provided with the representation of a real single-effect LiBr/water absorption refrigeration cycle. This should prove to be a valuable tool for design and research engineers to study and optimise LiBr/water chillers.     

Data broadcasting strategies for cognitive radio based AMI networks

Wireless Networks - Communication systems play an important role in smart grid (SG). Advanced Metering Infrastructure (AMI) is hybrid architecture in smart grid comprising of smart meters and...     

Insight into the binding of copper(II) by non-toxic biodegradable material (Oryza sativa): effect of modification and interfering ions

The present studies are focused on the use of non-toxic biodegradable straw from Oryza sativa in its simple and modified forms for the binding of copper(II) ions. A relatively new “green” method was adopted for modification with urea under microwaves. The studies have been performed by using the aqueous solution of Cu(II) ions with and without the presence of Cd(II) and Pb(II) as interfering ions. FTIR analysis showed the presence of oxygen- and nitrogen-containing functional groups in simple and modified materials. The emergence of new bands and shifts in the peaks confirmed the modification. The kinetics of the process was studied using the commonly employed mathematical models. Although Elovich model seemed to fit yet coefficient of determination did not reinforce it. Pseudo-second-order model was found to explain the kinetics of the binding of metal ions by simple and modified straw. The equilibrium was studied using the non-linear approach. Based on root mean square error values, it was found that Langmuir model was the most suitable model, followed by Temkin model. Surface areas were compared for single and multi-metal systems. The effect of pH was also studied. Under the studied set of conditions, the modification of straw caused a decrease in the equilibrium time of contact and increase in the biosorption capacities. The presence of other ions decreased the capacities drastically due the competition to bind with the materials.     

Electrochemical characterization of a Porphyridium cruentum-modified carbon paste electrode by cyclic voltammetry

A carbon paste electrode was modified with red algal specie of Porphyridium cruentum and then characterization of its electrocatalytic activity was demonstrated with cyclic voltammetric studies of potassium ferricyanide (K₃[Fe(CN)₆]) system. Stable and fast response of modified electrode to redox couple of [Fe(CN)₆]^3?/[Fe(CN)₆]^4? was highlighted by performing experiments in comparison to bare carbon paste electrode. Fourier transform infrared spectra revealed the functional moieties of bare and modified electrode. Electrochemical surface area and surface coverage capacity were calculated for both electrodes. The effect of scan rate helped evaluate the nature of electrode process, electron transfer mechanism, and kinetic parameters (rate constant, charge transfer coefficient).     

Electrical conductivity and thermoelectric power studies of solution-combustion-processed Ca2.76Cu0.24Co4O9

Nanocrystalline Ca_2.76Cu_0.24Co₄O₉ powders (25 nm in crystallite size) are synthesized by the solution combustion method, using aspartic acid as the combustion fuel. In this study, we discuss the effect of sintering temperature on the microstructure and thermoelectric properties of Ca_2.76Cu_0.24Co₄O₉. The density and grain size increase with an increase in sintering temperature. The Ca_2.76Cu_0.24Co₄O₉ sintered at 900 °C shows the largest value of electrical conductivity and Seebeck coefficient, resulting in the largest power factor (3.8×10^?4 W m^?1 K^?2 at 800 °C). This value is more than 22 times larger than that of the Ca_2.76Cu_0.24Co₄O₉ sintered at 940 °C (1.7×10^?5 W m^?1 K^?2 at 800 °C).     

Microwave-assisted urea-modified sorghum biomass for Cr (III) elimination from aqueous solutions

The present study concentrated on the use of an agro-waste biodegradable sorghum biomass in its simple and modified forms for the binding of Cr (III) ions. A relatively new method of modification was adopted using urea under microwave irradiation. FTIR analysis showed the presence of oxygen and nitrogen bearing functional groups in unmodified (UMS) and modified (MS) sorghum biomass. The appearance of new bands and shifts in the peaks confirmed the modification. The influence of different process parameters such as the adsorbent dose, solution pH, contact time, agitation speed and initial metal ion concentration was studied thoroughly to evaluate optimum conditions for adsorption. Maximum adsorption for Cr (III) ions occurred at pH 5.0–6.0 using UMS and MS. Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich isotherm models in a non-linear fashion were used to explain the phenomenon. Maximum adsorption capacity was 7.03 and 16.36 mg of Cr (III) per gram of UMS and MS, respectively. Adsorption mechanism was explored by pseudo-first- and pseudo-second-order kinetic models, and it was found that the process followed pseudo-second-order kinetics. Thermodynamic study indicated the process favorability. The study concluded that urea modification under microwave irradiation produces a non-toxic and more effective adsorbent for Cr (III) remediation by inducing new nitrogen bearing functional groups to sorghum biomass.     

Seed Oil Based Zinc Bioactive Polymers: Synthesis, Characterization and Biological Studies

Zinc containing oil based polyesteramide resins were synthesized by condensation polymerization reaction between castor/soyabean oil derived castor/soyabean fatty amide diol (HECA/HESA), Zn (OH)₂ and adipic acid. The conventional spectroscopic techniques such as FTIR, ¹HNMR, ¹³CNMR have been used to establish the structure of the polymers. Standard laboratory methods were used to study the physicochemical characteristics like acid value, hydroxyl value, saponification value, iodine value, specific gravity, and viscosity. The thermal behaviour of the polymers was analyzed by using thermo gravimetric analysis (TGA) and differential scanning calorimetry (DSC). In vitro antifungal (anticandidial) activity of the polymers was studied against C. albicans ATCC-10261, C. glabrata ATCC-90030 and C. tropicalis ATCC-750, respectively. Antibacterial activity against Gram positive (S. subtillis) and Gram negative bacteria (E. coli and S. typhi) was also examined. For more accuracy, growth curve studies were carried out with the polymer SZ showing higher biological activity against E. coli by using conventional spectrophotometer. The result showed that the polymers have potent anticandidial and antibacterial activities.     

Nitrogen biotransformation in anaerobic treatment of phenolic wastewater

Effect of nitrogen on methanogenesis of phenol has been evaluated. Methane generation rate constant (k) has been found to vary from 0.12 to 0.21 d^− 1. The process was not impaired due to reduction of COD:N from 300:10 to 300:1. However, a definite decreasing trend in k was noticed at COD:N < 300:1. The µ_b at 90 days (µ_b90) was reduced from 0.94 to 0.12. Gas generation completely ceased at COD:N equal to 300:0. The trend of sludge activity was also found to be similar to that of k and µ_b90. The variation of COD:N from 300:1 to 300:0 in a UASB reactor, did influence the conversion of phenol COD to methane COD i.e. the (i) CH₄-COD decreased from 90 to 40%, and (ii) cell yield reduced to 25-50%. The average cell yield was 3.5%. Percent N in cells varied from 10 to 14%. The activity of the sludge assessed as SMA was found in the range from 0.15 to 0.66 g CH₄-COD/g VSS/d. The optimum COD:N for phenolic wastewater from both bench-scale batch and continuous reactor study has been estimated to be 300:1.