290 research outputs found

    Comparison of growth of maiden trees of cultivars and genotypes of Cornelian cherry (Cornus mas L.) in a nursery

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    Cornelian cherry (Cornus mas L.) is still not a very popular fruit plant in Poland. Fruit growers have been recently increasingly interested in the cultivation of plants with fruits that can be widely used in processing. Fruits of Cornelian cherry can be eaten raw, and processed in various ways: for tinctures, juices, jams, silage, candied, etc. Both the fruits and preserves are characterised by high pro-health properties due to the content of vitamins, anthocyanins, and loganic acid. Cornus mas adapts well to the climate and soil conditions in Poland. The only limitation of its broader cultivation is lack of good planting material. The experiment investigated the efficiency of budding on two-year-old seedlings (Cornus mas L.) of several cultivars and genotypes of Cornelian cherry. Moreover, the height of plants, stem diameter, average number of shoots, number of leaves on selected shoots, and quality of roots were determined. The cornelian cherry maidens obtained by budding with dormant bud in August on two-year-old seedlings of Cornelian cherry (Cornus mas L.) constitutes high quality material suitable for establishing commercial plantations. Maiden trees of particular cultivars and genotypes of cornelian cherry significantly differ in height, diameter, number of branches and leaves, as well as the size of the root system. The diameter of the trunk is a good indicator of the quality of Cornelian cherry maiden, because it is closely positively correlated with the height of plants and the number of shoots

    Specific Heat of Liquid Helium in Zero Gravity very near the Lambda Point

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    We report the details and revised analysis of an experiment to measure the specific heat of helium with subnanokelvin temperature resolution near the lambda point. The measurements were made at the vapor pressure spanning the region from 22 mK below the superfluid transition to 4 uK above. The experiment was performed in earth orbit to reduce the rounding of the transition caused by gravitationally induced pressure gradients on earth. Specific heat measurements were made deep in the asymptotic region to within 2 nK of the transition. No evidence of rounding was found to this resolution. The optimum value of the critical exponent describing the specific heat singularity was found to be a = -0.0127+ - 0.0003. This is bracketed by two recent estimates based on renormalization group techniques, but is slightly outside the range of the error of the most recent result. The ratio of the coefficients of the leading order singularity on the two sides of the transition is A+/A- =1.053+ - 0.002, which agrees well with a recent estimate. By combining the specific heat and superfluid density exponents a test of the Josephson scaling relation can be made. Excellent agreement is found based on high precision measurements of the superfluid density made elsewhere. These results represent the most precise tests of theoretical predictions for critical phenomena to date.Comment: 27 Pages, 20 Figure

    Heat Capacity of ^3He in Aerogel

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    The heat capacity of pure ^3He in low density aerogel is measured at 22.5 bar. The superfluid response is simultaneously monitored with a torsional oscillator. A slightly rounded heat capacity peak, 65 mu K in width, is observed at the ^3He-aerogel superfluid transition, T_{ca}. Subtracting the bulk ^3He contribution, the heat capacity shows a Fermi-liquid form above T_{ca}. The heat capacity attributed to superfluid within the aerogel can be fit with a rounded BCS form, and accounts for 0.30 of the non-bulk fluid in the aerogel, indicating a substantial reduction in the superfluid order parameter consistent with earlier superfluid density measurements.Comment: 4 pages, 5 figure

    Bose-Einstein source of intermittency in hadronic interactions

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    The multi-particle Bose-Einstein correlations are the source of ''intermittency'' in high energy hadronic collisions. The power-law like increase of factorial moments with decreasing bin size was obtained by complete event weighing technique with gaussian approximation of space-time particle emitting source shape. The value of source size parameter was found to be higher than the common one fitted with the help of the standard Handbury Brown-Twiss procedure.Comment: 12

    Higher orders of the high-temperature expansion for the Ising model in three dimensions

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    The new algorithm of the finite lattice method is applied to generate the high-temperature expansion series of the simple cubic Ising model to β50\beta^{50} for the free energy, to β32\beta^{32} for the magnetic susceptibility and to β29\beta^{29} for the second moment correlation length. The series are analyzed to give the precise value of the critical point and the critical exponents of the model.Comment: Lattice2003(Higgs), 3 pages, 2 figure

    Minimal length scales for the existence of local temperature

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    We review a recent approach to determine the minimal spatial length scales on which local temperature exists. After mentioning an experiment where such considerations are of relevance, we first discuss the precise definition of the existence of local temperature and its physical relevance. The approach to calculate the length scales in question considers homogenous chains of particles with nearest neighbor interactions. The entire chain is assumed to be in a thermal equilibrium state and it is analyzed when such an equilibrium state at the same time exists for a local part of it. The result yields estimates for real materials, the liability of which is discussed in the sequel. We finally consider a possibility to detect the existence or non-existence of a local thermal state in experiment.Comment: review, 13 pages, 11 figure

    Heat capacity and thermal relaxation of bulk helium very near the lambda point

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    In October 1992 a low temperature experiment was flown on the Space Shuttle in low Earth orbit. The objective of the mission was to measure the heat capacity and thermal conductivity of helium very close to the lambda point with the smearing effect of gravity removed. We report preliminary results from the experiment, and compare them with related measurements performed on the ground. The sample was s sphere of helium 3.5 cm in diameter contained within a copper calorimeter of vey high thermal conductivity. The calorimeter was attached to a pair of high resolution paramagnetic salt thermometers with noise levels in the 10(exp -10) K range and suspended from a high stability thermal isolation system. During the mission we found that the resolution of the thermometers was degraded somewhat due to the impact of charged particles. This effect limited the useful resolution of the measurements to about two nanokelvins from the lambda point. The results reported here are limited to about ten nanokelvins from the transition

    The environment effect on operation of in-vessel mirrors for plasma diagnostics in fusion devices

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    First mirrors will be the plasma facing components of optical diagnostic systems in ITER. Mirror surfaces will undergo modification caused by erosion and re-deposition processes [1,2]. As a consequence, the mirror performance may be changed and may deteriorate [3,4]. In the divertor region it may also be obscured by deposition [5-7]. The limited access to in-vessel components of ITER calls for testing the mirror materials in present day devices in order to gather information on the material damage and degradation of the mirror performance, i.e. reflectivity. A dedicated experimental programme, First Mirror Test (FMT), has been initiated at the JET tokamak within the framework Tritium Retention Studies (TRS).Comment: 12th International Congress on Plasma Physics, 25-29 October 2004, Nice (France).Submitted by B. Schunke on behalf of V. Voytseny

    Perform a gyro test of general relativity in a satellite and develop associated control technology

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    The progress accomplished in the Stanford Gyro Relativity program during the period November 1974 to October 1975 was described. Gyro developments were continued in the main laboratory dewar, concentrating on the operation of a three axis gyro readout and on improvements to the methods of canceling trapped fields in the rotor; these efforts culminated in the first successful observation of the London moment in the spinning gyro rotor in March 1975. Following a review meeting at that time, a new goal was formulated for the next 12 to 18 months, namely to operate a gyroscope in the new ultra-low field facility with readout resolution approaching 1 arc-second. The following other tasks were also completed: (1) sputtering work, (2) magnetometry, (3) construction and installation of the North Star simulator, (4) analysis of torques on the gyro, especially in inclined orbits, (5) equivalence principle accelerometer, and (6) analysis of a twin-satellite test of relativity
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