Conversion of Methane to Methanol by a Low-Pressure Steam Plasma
Takayuki Tsuchiya and Satoru Iizuka
The paper investigates the performance of different bandpass modulation techniques in Additive White Gaussian Noise (AWGN) Channel and Multipath fading channel. This study examines the inherent attributes of the digital modulation to overcome the channel impairments. It reviews digital modulation techniques. The two channels- AWGN and Multipath channels were modeled and simulated in MATLAB Environment. The evaluation of the different modulation techniques was carried on the modeled channels. This was carried out to understand the contributions of channel characteristics to effective wireless communication. The BER for simulated modeled channels agreed with the theoretical results.. The performance of 64QAM is better compared to other bandpass modulation schemes in AWGN Channel. It was observed that the BER is higher in frequency selective channel as compared to the AWGN channel. It was also observed that multipath fading channel characteristic limits the data rate in wireless communication.
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Performance Studies on Wastewater Treatment Efficiency of an Artificial Wetland
Author(s)S. Ramakrishna Rao, S. Bala Prasad, P. S. Raja Sekhar and S.A. Rahiman
One of the reasons for deterioration of quality of lakes is the discharge of wastewater into them. The Kolleru Lake is one such natural fresh water wetland in Andhra Pradesh which has International importance as it was classified under Ramsar Convention. Its water quality is deteriorating due to discharge of inflows through small streams of untreated sewage generated from the surrounding towns and human activities in Krishna-Godavari delta region. It is essential to restore the quality of lake water. Among the existing low-cost treatment option for the treatment of inflow wastewater. Artificial wetland may be considered as viable treatment option for the treatment of inflow wastewater into Kolleru Lake. Hence, in the present study a lab scale artificial wetland system is developed and used to estimate the pollutants removal efficiency from the wastewater in three different seasons. Treatment effectiveness was evaluated which indicated the percentage values of mean removal efficiencies estimated in the Winter, Summer and Monsoon seasons for the parameters viz., TDS, TSS, BOD, COD, Nitrates and Phosphates are 34.13±1.41%, 41.45±7.71% and 36.83±2.60%;46.51±2.74%, 59.76±5.88% and 52.76±3.80%; 48.85±4.38%,60.29±8.31% and 54.11±5.19%; 46.35±3.74%, 54.01±3.53% and 50±.2.3%; 47.61±3.75%, 55.23±5.43% and 52.05±4.61%;38.61±3.39%, 49.71±1.15% and 42.05±2.56% respectively. The findings indicate that artificial wetland system is effective in removing pollutants from the wastewater.ely). It is observed that Bragg resonance occurs at the critical condition with the ratio 2S/L = 1.0 for all the cases of artificial beds considered, and maximum reflection appears as Bragg resonance occurs. It is also found that reflection coefficient from the sinusoidal artificial bed is much higher than those on other undulations which being similar for 2S/L different from unity. From the amplitude evolution analysis for each artificial bed, the first harmonic presents a regular oscillatory variation and gradually decays through wave traveling over artificial bed in the case with 2S/L =1. The second harmonic becomes significant in the cases with 2S/L<1, due to vortex generation in the flow field. The antinodes of standing wave due to Bragg resonance are consistently located at the front edge of an undulation patch, and the nodes in the lee side.
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