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We have prepared the quaternary thermoelectric nanoparticles, thallium tin antimony telluride Tl8Sb2-xSnxTe6 where the concentration of the Sn is (1.96, 1.97, 1.98, 1.99, 2.00) using the solid state reactions techniques. The nanoparticles have been prepared by the ball mining method. The Sn is doping in the quaternary compound which have changes their electrical and thermal properties. The crystal structure has been analyzed by the x-rays diffractometery (XRD), to determine the phase structure. The XRD data shows no extra peak; confirm the purity of the sample. The energy dispersive spectroscopy (EDX) shows the stoichiometric elemental ratio of the compound studied here. With the increasing concentration of the Sn in the compound, the electrical conductivity is decreases as temperature is increases while the Seebeck coefficient is increased as temperature is increases. At last, both electrical conductivity and Seebeck coefficient is increased. So that the power factor is also increased in the range of 300-550 K. The compound which has Sn concentration is 0.61, has the highest power factor at 550 K which is the 8.9 µWcm-1K-2. [ABSTRACT FROM AUTHOR]

The electrical and thermal properties of the doped Tellurium Telluride (Tl10Te6) chalcogenide nano-particles are mainly characterized by a competition between metallic (hole doped concentration) and semi-conducting state. We have studied the effects of Sn doping on the electrical and thermoelectric properties of Tl10-xSnxTe6 (1.00 ≤x≤ 2.00), nano-particles, prepared by solid state reactions in sealed silica tubes and ball milling method. Structurally, all these compounds were found to be phase pure as confirmed by the x-rays diffractometery (XRD) and energy dispersive X-ray spectroscopy (EDS) analysis. Additionally crystal structure data were used to model the data and support the findings. The particles size was calculated from the XRD data by Scherrer's formula. The EDS was used for an elemental analysis of the sample and declares the percentage of elements present in the system. The thermo-power or Seebeck co-efficient (S) was measured for all these compounds which show that S increases with increasing temperature from 295 to 550 K. The Seebeck coefficient is positive for the whole temperature range, showing p-type semiconductor characteristics. The electrical conductivity was investigated by four probe resistivity techniques revealed that the electrical conductivity decreases with increasing temperature, and also simultaneously with increasing Sn concentration. While for Seebeck coefficient the trend is opposite which is increases with increasing temperature. These increasing behavior of Seebeck coefficient leads to high power factor which are increases with increasing temperature and Sn concentration except For Tl8Sn2Te6 because of lowest electrical conductivity but its power factor increases well with increasing temperature. [ABSTRACT FROM AUTHOR]

In this research work the thermoelectric and electrical performance of Sn doped Tellurium Telluride Tl8.67SnxSb1.33-xTe6 (x=0.61, 0.63, 0.65, 0.67, 0.68, 0.70), was studied. The samples were synthesized by melting method. By XRD and EDX analysis it has been confirmed that single phase tetragonal crystal structure with no any other impurities. The See beck co-efficient (thermo power) (S) shows increasing positive trend showing p-type semiconductor characteristics with whole temperature range from 300 to 550 K. At ambient temperature complex behavior of See beck coefficient for Sn doped compounds has been observed initially S decreasing with increase in Sn concentration i.e. x=0.65, and then S increases with increase in Sn contents up to x=0.70. In additional the electrical conductivity (s) and the power factors have also shows the same complex behavior with the increase of Sn concentrations.. Telluride's are narrow band-gap semiconductors, with all elements in common oxidation states, according to (Tl+)9(Sb3+) (Te2-)6.It is found that the power factor is increases with Sn concentrations as well as increase in temperature range from 300-500 K. [ABSTRACT FROM AUTHOR]

Lipo-chitooligosaccharides (LCOs), or Nod factors, are host-specific bacteria-to-plant signal molecules essential for the establishment of a successful N(2)-fixing legume-rhizobia symbiosis. At submicromolar concentrations Nod factors induce physiological changes in host and non-host plants. Here we show that the Nod factor Nod Bj V(C18:1,MeFuc) of Bradyrhizobium japonicum 532C enhances germination of a variety of economically important plants belonging to diverse botanical families: Zea mays, Oryza sativa (Poaceae), Beta vulgaris (Chenopodaceae), Glycine max, Phaseolus vulgaris (Fabaceae), and Gossypium hirsutum (Malvaceae), under laboratory, greenhouse and field conditions. Similar increases in germination were observed for filtrates of genistein-induced cultures of B. japonicum 532C, while non-induced B. japonicum, induced Bj 168 (a nodC mutant of B. japonicum deficient in Nod factor synthesis) or the pentamer of chitin did not invoke such responses, demonstrating the role of Nod factor in the observed effects. In addition, three out of four synthetic LCOs evaluated also promoted germination of corn, soybean and Arabidopsis thaliana seeds. LCO also enhanced the early growth of corn seedlings under greenhouse conditions. These findings suggest the possible use of LCOs for improved crop production.

The LD50 of crude neem extract (N-4) and (N-9) was found to be 4.80% and 0.47%, respectively. The range of mortality was found to be increasing (at 95% confidence limit) with increase in concentration of solution.