585 research outputs found

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

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    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

    An Econometric Analysis of Markets for Canadian Lumber

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    An econometric model of markets for Canadian lumber has been developed and estimated from data for 33 years. Two equations for demand (domestic and export) and two for supply (domestic and import) were specified. Price elasticities of domestic demand and supply have been found to be inelastic. Per capita income appears to be the most important determinant of lumber consumption via its impact on housing demand in Canada. Housing starts in the United States determine most of the Canadian lumber exported to that country

    Primera cita de Botrytis cinerea sobre Lilium polyphyllum, especie en peligro de extinción en Uttarakhand, India

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    Dhyani, A. High Altitude Plant Physiology Research Centre. Srinagar, Pauri Garhwal, Uttarakhand, India.Nautiyal, B. P. Department of Horticulture. Aromatic and Medicinal Plant, Mizoram University, Aizawl, India.Nautiyal, M. C. High Altitude Plant Physiology Research Centre. Srinagar, Pauri Garhwal, Uttarakhand, India.Rivera, Marta Carolina. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Producción Vegetal. Cátedra de Fitopatología. Buenos Aires, Argentina.Prasad, D. University of Agriculture and Technology. College of Forestry and Hill Agriculture.Plant Pathology Section. Ranichauri, India.Singh, K. P. University of Agriculture and Technology. College of Forestry and Hill Agriculture.Plant Pathology Section. Ranichauri, India.157-159Lilium polyphyllum es una planta herbácea que se encuentra en estado de peligro en ambientes naturales de Uttarakhand, India. La enfermedad conocida como moho gris fue detectada sobre esta especie desde Julio a Agosto (2008-2009) causando muerte de inflorescencias y varas. Botrytis cinerea fue aislado consistentemente de inflorescencias. Su patogenicidad fue confirmada mediante inoculación de plantas de L. polyphyllum cultivadas en macetas en un invernáculo. Como resultado, se cita a Botrytis cinerea por primera vez como causante de moho gris sobre Lilium polyphyllum en India, cuyos síntomas son tizón de flores y varas. Esta enfermedad puede afectar seriamente a este hospedante en riesgo durante su estado reproductivo. A nuestro entender, no existe otro antecedente de B. cinerea sobre este hospedante

    Effect of moon light and lunar periodicity on the attraction of black cutworm Moth Agrotis Flammatara (Schiffer - Mueller) on light trap

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    The effect of moon light and lunar periodicty on the attraction of cutworm moth, Agrotis flammatra (Schiffer Mueller) was studied during active periods (rainy season) in 1997 and 1998 at Horticulture Research Block of Hill Campus, Ranichauri (1600m ASL). In the light trap, a mercury vapour electric bulb (160 Watt) was used as the source of light. The moths attracted to the light trap during the active period were collected and recorded daily. Number of moths trapped on the light trap was correlated with the degree of moon phase of different days of a lunar cycle. The results indicated that the number of moths attracted to light trap was consistently very low during moonlight nights around full moon. A highly significant inverse linear correlation between the degree of moon phase and light trap catches was observed. On the average, the attraction response of cutworm moths was stronger in descending phase as compared to ascending phase

    Cultivation of Angelica archangelica Linn.: evaluation for economical viability at two different climatic conditions

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    ABSTRACT Cultivation of an important sub alpine-alpine medicinal and aromatic herb, Angelica archangelica Linn. (Apiaceae), was carried out at two different climatic zone at 2200 m asl (Pothivasa, PV) and 3600 m asl (Tungnath, TN) altitudes in Garhwal, North west Himalaya, India. These altitudes represent temperate and alpine region of the Himalaya. Since the species has a very few wild populations, cultivation of the species is recommended for its medicinal use. After the establishment of sufficient quantity of seedlings, they were transplanted in both sites at the age of two, three and four months for the comparative accounts on survival, growth and yield and, to test the appropriate age of seedlings for transplantation and climatic suitability for cultivation of the species. Organic cultivation protocol was adopted by using different farm yard manure (FYM) as treatments. Yield was minimum in youngest seedlings (two months old ) transplanted at TN in ordinary alpine soil (control) and maximum under polyhouse beds at PV after three years of growth. Observations on yield at different climatic zone revealed that it was maximum in PV (temperate site) as compared to alpine site (natural site) in all treatments. Seedlings of different age also had better survival, growth and yield at the temperate site though; two months old seedlings after transplantation had comparatively slow growth and yield than those of three and four months seedlings. These observations clearly suggested that temperate region (2200 m) is suitable for cultivation of A. archangelica. Addition of manure (leaf litter in particular) and polyhouse cultivation further improved the yield. Economical viability of the cultivation was also observed and presented here

    Effect of hydrostatic pressure and alloying on thermoelectric properties of van der Waals solid KMgSb: An \textit{ab-initio} study

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    Through a combined first-principles and Boltzmann transport theory, we systematically investigate the thermal and electrical transport properties of the unexplored ternary quasi two-dimensional KMgSb system of KMgX (X = P, As, Sb, and Bi) family. Herein, the transport properties of KMgSb under the application of hydrostatic pressure and alloy engineering are reported. At a carrier concentration of 8×1019 cm3\sim8\times10^{19}~\mathrm{cm^{-3}}, the figure of merit zT (0.75\sim0.75) for both the nn-type and pp-type of KMgSb closely matched, making it an attractive option for engineering both legs of a thermoelectric device using the same material. This is particularly desirable for high-performance thermoelectric applications. Furthermore, the zT value increases as pressure decreases, further enhancing its potential for use in thermoelectric devices. In the case of substitutional doping (replacing 50 \% Sb by Bi atom), we observed 49 %\sim49~\% (in-plane) increase in the peak thermoelectric figure of merit (zT). The maximum zT value obtained after alloy engineering is 1.45\sim1.45 at 900~K temperature. Hydrostatic pressure is observed to be a great tool to tune the lattice thermal conductivity (κL\kappa_L). We observed that the negative pressure-like effects could be achieved by chemically doping bigger-size atoms, especially when κL\kappa_L is a property under investigation. Through our computational investigation, we explain that hydrostatic pressure and alloy engineering may improve thermoelectric performance dramatically.Comment: 10 pages, 8 figures, and Supplementary Informatio

    Ecological features and traditional knowledge of Roscoea alpina Royle a medicinal plant in Himalaya

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    167-173Roscoea alpina Royle (Zingiberaceae) commonly known as Kakoli is a perennial medicinal plant endemic to the Himalayas. It has been used in vitality strengthening Ayurveda groups i.e., Astavarga and Jeevaniyagana and in preparation of Ayurvedic formulations e.g., Chyavanprasha and Divya Pidantak Tail. Considering its medicinal uses, high demand and overexploitation, natural habitats were surveyed in subalpine and alpine regions of Garhwal Himalaya for population estimation and to identify elite germplasm. R. alpina frequency was recorded more than 60% in Tungnath, Dayara, Valley of Flowers and Kedarnath populations. However, plant density and area occupied were low compared to other species of subalpine and alpine site. For threat category assessment, IUCN Red List Categories and Criteria were used and conservation status was assigned, based on site to site and for entire Garhwal region of the Western Himalaya. R. alpina, based on extent of occurrence was categorized as Vulnerable and based on number of mature individuals as Endangered for the Garhwal Himalaya. Further, habitat destruction and degradation were the major threats for population reduction in the wild. Morphological variation revealed plants from Tungnath and Kedarnath may be used for future propagation and domestication programs

    Magic structures and quantum conductance of [110] silver nanowires

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    We investigate the pathway of thinning process for transient [110] nanowires (NWs) of Ag. The result is in good agreement with experimental observations. An unambiguous identification of the structure of a NW requires at least two views along different directions. In the cases where two views of different NW structures are practically the same for very thin NWs which pose experimental difficulty due to small signal-to-noise ratio, our theoretical analysis helps distinguish these structures. On the basis of conductance (G) calculations vis-a-vis the structure of transient NWs, the puzzling experimental observation of fractionally quantized G values is explained by considering the existence of mixed structures for thin wires.open353

    Spin and current transport in the robust half-metallic magnet cc-CoFeGe

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    Spintronics is an emerging form of electronics based on the electrons' spin degree of freedom for which materials with robust half-metallic ferromagnet (HMF) character are very attractive. Here we determine the structural stability, electronic, magnetic, and mechanical properties of the half-Heusler (hH) compound CoFeGe, in particular also in its cubic form. The first-principles calculations suggest that the electronic structure is robust with 100 \% spin polarization at the Fermi level under hydrostatic pressure and uni-axial strain. Both the longitudinal and Hall current polarization are calculated and the longitudinal current polarization (PLP_{L}) is found to be >99%>99\% and extremely robust under uniform pressure and uni-axial strain. The anomalous Hall conductivity (AHC) and Spin Hall conductivity (SHC) of hH cubic CoFeGe (\textit{c}-CoFeGe) are found to be 100\sim -100 S/cm and 39 /e\sim 39~\hbar/e S/cm, respectively. Moreover, the Curie temperature of the alloy is calculated to be \sim524 K with a 3 μB\mu_{B} magnetic moment. Lastly, the calculated mechanical properties indicate that \textit{c}-CoFeGe is ductile and mechanically stable with a bulk modulus of \approx 154 GPa. Overall, this analysis reveals that cubic CoFeGe is a robust half-metallic ferromagnet and an interesting material for spintronic applications.Comment: 8 pages, 6 figures, and 2 table
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