AMCTD: Adaptive Mobility of Courier nodes in Threshold-optimized DBR Protocol for Underwater Wireless Sensor Networks

In dense underwater sensor networks (UWSN), the major confronts are high error probability, incessant variation in topology of sensor nodes, and much energy consumption for data transmission. However, there are some remarkable applications of UWSN such as management of seabed and oil reservoirs, exploration of deep sea situation and prevention of aqueous disasters. In order to accomplish these applications, ignorance of the limitations of acoustic communications such as high delay and low bandwidth is not feasible. In this paper, we propose Adaptive mobility of Courier nodes in Threshold-optimized Depth-based routing (AMCTD), exploring the proficient amendments in depth threshold and implementing the optimal weight function to achieve longer network lifetime. We segregate our scheme in 3 major phases of weight updating, depth threshold variation and adaptive mobility of courier nodes. During data forwarding, we provide the framework for alterations in threshold to cope with the sparse condition of network. We ultimately perform detailed simulations to scrutinize the performance of our proposed scheme and its comparison with other two notable routing protocols in term of network lifetime and other essential parameters. The simulations results verify that our scheme performs better than the other techniques and near to optimal in the field of UWSN.Comment: 8th International Conference on Broadband and Wireless Computing, Communication and Applications (BWCCA'13), Compiegne, Franc

Breakdown testing of wiring insulation

The dielectric strength of potential wiring insulation, recommended by NASA Lewis Research Center to replace existing M81381 (polyimide), was evaluated at high temperature. Results, given in view-graph format, show that their is no dependence of breakdown strength on temperature for the constructions tested and that their was little effect of frequency on the breakdown characteristics

Interference of five problematic weed species with rice growth and yield

Five weed species namely, Cyperus rotundus L., Cyperus difformis L., Echinochloa colonum (L.) Link., Paspalum paspaloides (Mich.) Scribner, and Marsilea minuta L. were selected for the assessment of their level of competition with two commonly grown rice varieties viz. Basmati-385 and Super Basmati. Root and shoot growth as well as grain yield, in both rice cultivars, were adversely affected due to the weed competition in the field experiments. In general, Super Basmati was found to be comparatively more tolerant to weed infestation than Basmati-385. There were 6 to 40% and 21 to 56% reduction in grain yield of Super Basmati and Basmati-385, respectively, due to different weed species. E. colonum was found to be the most damaging weed which resulted in the highest grain yield losses of 56 and 42% in Basmati-385 and Super Basmati, respectively. P. paspaloides was found to be the second most damaging weed species which caused 47% yield losses in Basmati-385. It was concluded from the study that E. colonum was the most competitive weed. It resulted in the highest yield losses in rice especially in var. Basmati-385.Keywords: Rice, weeds, yield losses

Herbicidal effects of aqueous extracts of three Chenopodium species on Avena fatua

Herbicidal effects of aqueous leaf extracts of three Chenopodium species; Chenopodium album L., Chenopodium murale L. and Chenopodium ambrosioides were evaluated on wild oat (Avena fatua L.), one of the problematic weeds of wheat. Among the aqueous extracts of 0, 2, 4 and 6% (w/v) employed in bioassays, 6% of C. album and 2% of C. murale caused significant inhibition in germination of A. fatua resulting in 66 and 34% decline in germination, respectively. Lower concentration of 2% of all the three Chenopodium species enhanced seedling growth of A. fatua. The highest extract concentration of C. album (6%) markedly suppressed both length and biomass of shoot of test weed species. The highest herbicidal effect was exhibited by 6% C. album leaf extract, resulting in 88, 89, 70 and 92% reduction in maximum and total root length, number of roots and root biomass, respectively. This study concludes that the aqueous leaf extracts of C. album contain herbicidal constituents for the management of A. fatua.Key words: Aqueous extracts, Avena fatua, Chenopodium, natural herbicides