7,424 research outputs found

    The Life and Career of Jonathan Duncan, 1756-1795.

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    This thesis is a study of the life and career of Jonathan Duncan, 1756-1795. It covers his career until he left the post of Resident at Benares; the period of his governorship of Bombay has been omitted. Chapter I is a sketch of Duncan's career till his appointment to the residency of Benares. At attempt has been made to show how in his subordinate positions he received training for more responsible work. Chapter II depicts the condition of Benares at the time of his appointment and the problems which he was confronted with. In Chapter III Duncan's economic policy has been discussed with reference to his reforms in tariffs, land revenue, opium and indigo. Chapter IV deals with judicial reforms and measures for the maintenance of law and order initiated at his instance. In Chapter V his attitude to Indian society, his humanity and love for Hindu learning have been discussed; while Chapter IV deals with his achievements in Malabar - his contribution to the establishment of a regular administrative machinery, and settlements with the several Rajas. In conclusion a summary of his main reforms has been attempted, and his claims to greatness examined

    Equation of State for Neutralino Star as a Form of Cold Dark Matter

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    In order to study the structure of neutralino star and dark galaxy, we consider dynamical interactions due to boson-exchange in the neutralino matter. Taking into account interactions of neutralinos with bosons, we derive the equation of state (EOS) of neutralino stars in terms of the relativistic mean field approach. Then we apply the resulting EOS to investigate properties of the neutralino star such as its density profile and mass limit. For example, if the neutralino mass is around 1 TeV, the Oppenheimer mass limit of the neutralino star is obtained as 6.06×107M6.06\times 10^{-7}M_\odot, and the corresponding radius is about 7.8 mm. Actually, due to an increasing annihilation rate as indicated by our calculation, this dense state can never be realized in practice. Our results also show that the low density neutralino star may be a possible aggregation of the cold dark matter.Comment: 5 pages, 5 figures; v2: matches published versio

    Alfvenic Heating of Protostellar Accretion Disks

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    We investigate the effects of heating generated by damping of Alfven waves on protostellar accretion disks. Two mechanisms of damping are investigated, nonlinear and turbulent, which were previously studied in stellar winds (Jatenco-Pereira & Opher 1989a, b). For the nominal values studied, f=delta v/v_{A}=0.002 and F=varpi/Omega_{i}=0.1, where delta v, v_{A} and varpi are the amplitude, velocity and average frequency of the Alfven wave, respectively, and Omega_{i} is the ion cyclotron frequency, we find that viscous heating is more important than Alfven heating for small radii. When the radius is greater than 0.5 AU, Alfvenic heating is more important than viscous heating. Thus, even for the relatively small value of f=0.002, Alfvenic heating can be an important source of energy for ionizing protostellar disks, enabling angular momentum transport to occur by the Balbus-Hawley instability.Comment: 21 pages, 9 figures. Accepted for publication in Ap

    Charge Lattices and Consistency of 6D Supergravity

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    We extend the known consistency conditions on the low-energy theory of six-dimensional N = 1 supergravity. We review some facts about the theory of two-form gauge fields and conclude that the charge lattice Gamma for such a theory has to be self-dual. The Green-Schwarz anomaly cancellation conditions in the supergravity theory determine a sublattice of Gamma. The condition that this sublattice can be extended to a self-dual lattice Gamma leads to a strong constraint on theories that otherwise appear to be self-consistent.Comment: 15 pages. v2: minor changes; references, additional example added; v3: minor corrections and clarifications added, JHEP versio

    Dynamics of Magnetic Flux Elements in the Solar Photosphere

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    The interaction of magnetic fields and convection is investigated in the context of the coronal heating problem. We study the motions of photospheric magnetic elements using filtergrams obtained at the Swedish Vacuum Solar Telescope at La Palma. We use potential-field modeling to extrapolate the magnetic and velocity fields to larger height. We find that the velocity in the chromosphere can be locally enhanced at the separatrix surfaces between neighboring flux tubes. The predicted velocities are several km/s, significantly larger than those of the photospheric flux tubes, which may have important implications for coronal heating. sComment: submitted to ApJ, 21 pages, 10 figure

    U-Duality and Symplectic Formulation of Dilaton-Axion Gravity

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    We study a bosonic four--dimensional effective action corresponding to the heterotic string compactified on a 6--torus (dilaton--axion gravity with one vector field) on a curved space--time manifold possessing a time--like Killing vector field. Previously an existence of the SO(2,3)Sp(4,R)SO(2,3)\sim Sp(4, R) global symmetry (UU--duality) as well as the symmetric space property of the corresponding σ\sigma--model have been established following Neugebauer and Kramer approach. Here we present an explicit form of the Sp(4,R)Sp(4, R) generators in terms of coset variables and construct a representation of the coset in terms of the physical target space coordinates. Complex symmetric 2×22\times 2 matrix ZZ (``matrix dilaton --axion'') is introduced for which UU--duality takes the matrix valued SL(2,R)SL(2, R) form. In terms of this matrix the theory is further presented as a K\"ahler σ\sigma--model. This leads to a more concise 2×22\times 2 formulation which opens new ways to construct exact classical solutions. New solution (corresponding to constant ImZ{\rm Im} Z ) is obtained which describes the system of point massless magnetic monopoles endowed with axion charges equal to minus monopole charges. In such a system mutual magnetic repulsion is exactly balanced by axion attraction so that the resulting space time is locally flat but possesses multiple Taub--NUT singularities.Comment: LATEX, 20 pages, no figure

    Sea truth data collection: estimation of diffuse attenuation coefficient in ocean colour mapping

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    Phytoplankton pigments in the ocean waters are the prime synthesisers in marine food chain which in turn terminate as pelagic or benthic nekton. They perform about half of the total global photosynthesis and compr is ethe upper consumption and production. These are the substances that have definite spectral characteristics and thereby govern the ocean colour

    Application of LANDSAT MSS data in ocean colour sensing

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    Landsat MSS data off Cochin Coast was analysed ond on attempt made to look in to the relationship between MSS gray values and concentration of pigment/particulate matter. MSS band 4 and 5 showed the maximum gray value range as compared to band 6 and 7. A density sliced image of band 4 was generated in the form of Q color coded image showing the gray levels corresponding to various pigment levels

    Oceanographic parameters and their relationship to fish catch estimation: a case study in coastal waters north of Cochin during 1981

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    Coastal waters in the North of Cochin was selected for the present study. This area is well known for the occurrence and abundance of fish schools of oil sardine (Sardinella Iongiceps) and mackerel (Rastrelliger Kanagurta) allowing the period after SW monsoon in the Indian Ocea

    Review of Top Quark Physics Results

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    As the heaviest known fundamental particle, the top quark has taken a central role in the study of fundamental interactions. Production of top quarks in pairs provides an important probe of strong interactions. The top quark mass is a key fundamental parameter which places a valuable constraint on the Higgs boson mass and electroweak symmetry breaking. Observations of the relative rates and kinematics of top quark final states constrain potential new physics. In many cases, the tests available with study of the top quark are both critical and unique. Large increases in data samples from the Fermilab Tevatron have been coupled with major improvements in experimental techniques to produce many new precision measurements of the top quark. The first direct evidence for electroweak production of top quarks has been obtained, with a resulting direct determination of VtbV_{tb}. Several of the properties of the top quark have been measured. Progress has also been made in obtaining improved limits on potential anomalous production and decay mechanisms. This review presents an overview of recent theoretical and experimental developments in this field. We also provide a brief discussion of the implications for further efforts.Comment: 119 pages, 55 figure
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