15,598 research outputs found

    Latvia's democratic resistance: a forgotten episode from the Second World War

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    In summer 1943 politicians representing the four main political parties of Latvia's democratic years came together to establish a movement which would both resist the German occupation and prevent the return of the Red Army. They considered the key to re-establishing Latvia as an independent democratic state was to make contact with Britain, and they hoped to do this by a combination of military and diplomatic activity. Once contact with Sweden had been established this Latvian Central Council planned to combine a diplomatic offensive abroad with an insurrection within Latvia. The diplomatic offensive was partly obstructed by the Foreign Office, but that did not prevent the Latvian Central Council working closely with the British Secret Service as it first brought out of Latvia potential members of a Government in Exile, and then began to prepare for an insurrection. Planned to coincide with the arrival of the Red Army and the withdrawal of the Germans, the military wing of the Latvian Central Council intended to seize part of the Courland coast and hold it until British or Swedish forces intervened to prevent them being crushed by the Red Army, thus forcing the Soviets to negotiate about the future status of Latvia. The plans of the Latvian Central Council relied heavily on stories circulating in Sweden that the British were indeed about to intervene in the Baltic, and it is argued here that there was more to this than mere loose talk. The dilemma of whether or not to stage an insurrection was resolved by the Germans, who arrested General Kurelis, the leader of the insurrection and the man designated the interim leader of independent Latvia. The surviving forces of the Latvian Central Council established themselves as an underground army and waited for news from Britain that the time had come to rise. When no such message had come by summer 1945, many underground groups started moves towards a national uprising; to prevent this the Latvian Central Council used its surviving organization to instruct its underground fighters not to take up arms against the Soviets but to wait on diplomacy

    Spherical solid-propellant rocket motor Patent

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    Spherical solid propellant rocket engine desig

    Ground-based NIR emission spectroscopy of HD189733b

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    We investigate the K and L band dayside emission of the hot-Jupiter HD 189733b with three nights of secondary eclipse data obtained with the SpeX instrument on the NASA IRTF. The observations for each of these three nights use equivalent instrument settings and the data from one of the nights has previously reported by Swain et al (2010). We describe an improved data analysis method that, in conjunction with the multi-night data set, allows increased spectral resolution (R~175) leading to high-confidence identification of spectral features. We confirm the previously reported strong emission at ~3.3 microns and, by assuming a 5% vibrational temperature excess for methane, we show that non-LTE emission from the methane nu3 branch is a physically plausible source of this emission. We consider two possible energy sources that could power non-LTE emission and additional modelling is needed to obtain a detailed understanding of the physics of the emission mechanism. The validity of the data analysis method and the presence of strong 3.3 microns emission is independently confirmed by simultaneous, long-slit, L band spectroscopy of HD 189733b and a comparison star.Comment: ApJ accepte

    Gluino Air Showers as a Signal of Split Supersymmetry

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    It has been proposed recently that, within the framework of split Supersymmetry, long lived gluinos generated in astrophysical sources could be detected using the signatures of the air showers they produce, thus providing a lower bound for their lifetime and for the scale of SUSY breaking. We present the longitudinal profile and lateral spread of GG-hadron induced extensive air showers and consider the possibility of measuring them with a detector with the characteristics of the Pierre Auger Observatory.Comment: 4 pages, 3 eps figure

    Molecular Signatures in the Near Infrared Dayside Spectrum of HD 189733b

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    We have measured the dayside spectrum of HD 189733b between 1.5 and 2.5 microns using the NICMOS instrument on the Hubble Space Telescope. The emergent spectrum contains significant modulation, which we attribute to the presence of molecular bands seen in absorption. We find that water (H2O), carbon monoxide (CO), and carbon dioxide (CO2) are needed to explain the observations, and we are able to estimate the mixing ratios for these molecules. We also find temperature decreases with altitude in the ~0.01 < P < ~1 bar region of the dayside near-infrared photosphere and set an upper limit to the dayside abundance of methane (CH4) at these pressures.Comment: 13 pages, 3 figures. accepted in Astrophysical Journal Letter

    Griffiths phase-like behaviour and spin-phonon coupling in double perovskite Tb2_{2}NiMnO6_{6}

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    The Griffiths phase-like features and the spin-phonon coupling effects observed in Tb2_2NiMnO6_6 are reported. The double perovskite compound crystallizes in monoclinic P21/nP2_1/n space group and exhibits a magnetic phase transition at TcT_c \sim 111 K as an abrupt change in magnetization. A negative deviation from ideal Curie-Weiss law exhibited by 1/χ(T)\chi(T) curves and less-than-unity susceptibility exponents from the power-law analysis of inverse susceptibility are reminiscent of Griffiths phase-like features. Arrott plots derived from magnetization isotherms support the inhomogeneous nature of magnetism in this material. The observed effects originate from antiferromagnetic interactions which arise from inherent disorder in the system. Raman scattering experiments display no magnetic-order-induced phonon renormalization below TcT_c in Tb2_2NiMnO6_6 which is different from the results observed in other double perovskites and is correlated to the smaller size of the rare earth. The temperature evolution of full-width-at-half-maximum for the {\it stretching} mode at 645 cm1^{-1} presents an anomaly which coincides with the magnetic transition temperature and signals a close connection between magnetism and lattice in this material.Comment: 17 pages, 8 figures; accepted in J. Appl. Phy

    Victoria Lancers : Quadrilles

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    https://digitalcommons.library.umaine.edu/mmb-ps/1700/thumbnail.jp

    Using {\sc top-c} for Commodity Parallel Computing in Cosmic Ray Physics Simulations

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    {\sc top-c} (Task Oriented Parallel C) is a freely available package for parallel computing. It is designed to be easy to learn and to have good tolerance for the high latencies that are common in commodity networks of computers. It has been successfully used in a wide range of examples, providing linear speedup with the number of computers. A brief overview of {\sc top-c} is provided, along with recent experience with cosmic ray physics simulations.Comment: Talk to be presented at the XI International Symposium on Very High Energy Cosmic Ray Interaction
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