Solar flare neon and solar cosmic ray fluxes in the past using gas-rich meteorites

Methods were developed earlier to deduce the composition of solar flare neon and to determine the solar cosmic ray proton fluxes in the past using etched lunar samples and at present, these techniques are extended to gas rich meteorites. By considering high temperature Ne data points for Pantar, Fayetteville and other gas rich meteorites and by applying the three component Ne-decomposition methods, the solar cosmic ray and galactic cosmic ray produced spallation Ne components from the trapped SF-Ne was resolved. Using appropiate SCR and GCR production rates, in the case of Pantar, for example, a GCR exposure age of 2 m.y. was estimated for Pantar-Dark while Pantar-Light yielded a GCR age of approx. 3 m.y. However the SCR exposure age of Pantar-Dark is two orders of magnitude higher than the average surface exposure ages of lunar soils. The possibility of higher proton fluxes in the past is discussed

AM-DisCNT: Angular Multi-hop DIStance based Circular Network Transmission Protocol for WSNs

The nodes in wireless sensor networks (WSNs) contain limited energy resources, which are needed to transmit data to base station (BS). Routing protocols are designed to reduce the energy consumption. Clustering algorithms are best in this aspect. Such clustering algorithms increase the stability and lifetime of the network. However, every routing protocol is not suitable for heterogeneous environments. AM-DisCNT is proposed and evaluated as a new energy efficient protocol for wireless sensor networks. AM-DisCNT uses circular deployment for even consumption of energy in entire wireless sensor network. Cluster-head selection is on the basis of energy. Highest energy node becomes CH for that round. Energy is again compared in the next round to check the highest energy node of that round. The simulation results show that AM-DisCNT performs better than the existing heterogeneous protocols on the basis of network lifetime, throughput and stability of the system.Comment: IEEE 8th International Conference on Broadband and Wireless Computing, Communication and Applications (BWCCA'13), Compiegne, Franc

Electronic phase separation in the rare earth manganates, (La1-xLnx)0.7Ca0.3MnO3 (Ln = Nd, Gd and Y)

All the three series of manganates showsaturation magnetization characteristic of ferromagnetism, with the ferromagnetic Tc decreasing with increasing in x up to a critical value of x, xc (xc = 0.6, 0.3, 0.2 respectively for Nd, Gd, Y). For x > xc, the magnetic moments are considerably smaller showing a small increase around TM, the value of TM decreasing slightly with increase in x or decrease in . The ferromagnetic compositions (x xc) show insulator-metal (IM) transitions, while the compositions with x > xc are insulating. The magnetic and electrical resistivity behavior of these manganates is consistent with the occurrence of phase separation in the compositions around xc, corresponding to a critical average radius of the A-site cation, , of 1.18 A. Both Tc and TIM increase linearly when < rA > > or x xc as expected of a homogenous ferromagnetic phase. Both Tc and TM decrease linearly with the A-site cation size disorder at the A-site as measured by the variance s2. Thus, an increase in s2 favors the insulating AFM state. Percolative conduction is observed in the compositions with > < rAc >. Electron transport properties in the insulating regime for x > xc conforms to the variable range hopping mechanism. More interestingly, when x > xc, the real part of dielectric constant (e') reaches a high value (104-106) at ordinary temperatures dropping to a very small (~500) value below a certain temperature, the value of which decreases with decreasing frequency.Comment: 27 pages; 11 figures, Submitted to J.Phys:Condens Matte

Extraction of Cr(VI) from Orthophosphoric Acid Solutions by Trilauryl Amine

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Growth, reproduction and sporulation of marine alga Gelidium pusillum(Stackhouse) Le Jolis

Seasonal aspects of growth. reproduction and spore output in G. pusillum growing (Sept. I 976-Feb. 1979) at Visakhapatnam coast were described. Plants occurred throughout the year with maximum growth in Sept. and Oct. and minimum between Jan. and April. Tetrasporophytes were predominant over the cystocarpic plants and seasonality was not observed in the abundance of these fruiting plants. Under laboratory conditions tetraspore and carpospore shedding was maximum on the 1st d and spore output gradually decreased from 2nd d onwards. Seasonal variations were not observed in the formation of sori and discharge of spores

Effect of thermal stress on spore shedding in some red algae of Visakhapatnam coast

Effect of thermal stress on the liberation of tetraspores from Gelidium pusillum (Stackhouse) LeJolis, PterocladiLl heteroplatos (Boergesen) Umamaheswara Rao and Kaliaperurna.l and Gelidiopsis variabilis( Greville) Schmitz was studied. in response to temperatures lower (0° -lOOC)and higher( 40° -45°C)than the tolerance limits of plants. Spore liberation was seen in these algae exposed to low and high temperatures for short durations but the output decreased with increase in the duration of treatment. The temperature tolerance capacity varied in the algae tested

Seasonal growth and reproduction of Gelidiopsis variabilis (Greville) Schmitz

Seasonal variations in growth, fruiting and sporulation of Gelidiopsis variabilis (Greville) Schmitz occurring on the Visakhapatnam coast have been described. Only tetrasporophytes and vegetative plants were found in the populations analysed for 21/2 yr and seasonal changes were more marked in the abundance of tetrasporophytcs formation of stichidia and in the spore output than in the stature of the plants. Maximum development of the plants was observed each year between October and January-February and peak reproductive activity from July to September