118,109 research outputs found

    Newly found evidence of Sun-climate relationships

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    Solar radiation cycles drive climatic changes intercyclically. These interdecadal changes were detected as variations in solar total irradiances over the time period of recorded global surface-air-temperature (SAT) and have been restored utilizing Earth Radiation Budget Channel 10C measurements (1978-1990), Greenwich Observatory faculae data (1874-1975), and Taipei Observatory Active Region data (1964-1991). Analysis of the two separate events was carried out by treating each as a discrete time series determined by the length of each solar cycle. The results show that the global SAT responded closely to the input of solar cyclical activities, S, with a quantitative relation of T = 1.62 * S with a correlation coefficient of 0.61. This correlation peaks at 0.71 with a built-in time lag of 32 months in temperature response. Solar forcing in interannual time scale was also detected and the derived relationship of T = 0.17 * S with a correlation coefficient of 0.66 was observed. Our analysis shows derived climate sensitivities approximately fit the theoretical feedback slope, 4T(sup 3)

    Comparison of wind and turbulence measurements from Doppler lidar and instrumented aircraft

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    Wind fields were measured with the ground based lidar, NOAA Wave Propagation Laboratory and with the NASA B-57B instrumented aircraft. The remotely sensed winds are compared with the in situ aircraft measurements. Three flight plans were carried out during the two different field programs. At NASA/MSFC the aircraft circled while the lidar scanned conically and the aircraft flew 6 deg approach path along the fixed lidar beam. The aircraft flew an approach along the lidar beam directed south-north (parallel to the mountain range) and a climbout along the lidar beam which alternately shifted east-west (perpendicular to the mountain range). Turbulence intensities and spectra were calculated from the temporal fluctuations in the lidar-measured radial wind speed component. These field tests provided unique sets of data to examine the mean wind and turbulence measurements made by remote sensing instruments. The comparison of aircraft measured turbulence intensities and spectra with lidar time histories of radial wind speed were in good agreement

    Hamiltonian formalism of the DNLS equation with nonvanished boundary value

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    Hamiltonian formalism of the DNLS equation with nonvanishing boundary value is developed by the standard procedure.Comment: 11 page

    Examining Pre-Service Teacher Candidates’ Sources and Levels of Knowledge about Autism Spectrum Disorders

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    This study was designed to identify what pre-service teacher candidates knew about autism spectrum disorder (ASD) and how they had acquired that knowledge in order to design more effective preparation courses. Teacher candidates (N=87) from three teacher preparation programs completed questionnaires during, or prior to, their first special education course. The findings indicate a relationship between sources of knowledge about ASD and actual levels of knowledge. Based on the findings, the authors argue that there is a need for coursework that focuses on effective intervention strategies and utilizes direct opportunities for teacher candidates to work with students with ASD

    Revised Huang-Yang multipolar pseudopotential

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    A number of authors have recently pointed out inconsistencies of results obtained with the Huang-Yang multipolar pseudo-potential for low-energy scattering [K. Huang and K. C. Yang, Phys. Rev. A, v 105, 767 (1957); later revised in K. Huang, ``Statistical Mechanics'', (Wiley, New York, 1963)]. The conceptual validity of their original derivation has been questioned. Here I show that these inconsistencies are rather due to an {\em algebraic} mistake made by Huang and Yang. With the corrected error, I present the revised version of the multipolar pseudo-potential

    A study of the ferromagnetic transition of SrRuO3SrRuO_3 in nanometer thick bilayers with YBa2Cu3OyYBa_2Cu_3O_y, La1.88Sr0.12CuO4−yLa_{1.88}Sr_{0.12}CuO_{4-y}, Au and Cr: Signature of injected carriers in the pseudogap regime

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    The hypothesis regarding the existence of uncorrelated pre-formed pairs in the pseudogap regime of superconducting YBa2Cu3OyYBa_2Cu_3O_y is tested experimentally using bilayers of YBa2Cu3OyYBa_2Cu_3O_y and the itinerant ferromagnet SrRuO3SrRuO_3. In our study, we monitor the influence of YBa2Cu3OyYBa_2Cu_3O_y on TpT_p, the ferromagnetic ordering temperature of SrRuO3SrRuO_3. Here, TpT_p is the temperature of maximum dM/dT or dR/dT where M and R are the magnetization and resistance of SrRuO3SrRuO_3, respectively. We compare the results with similar measurements carried out on bilayers of La1.88Sr0.12CuO4−yLa_{1.88}Sr_{0.12}CuO_{4-y}, AuAu and CrCr with SrRuO3SrRuO_3. We find that in bilayers made of underdoped 10 nm YBa2Cu3OyYBa_2Cu_3O_y/5 nm SrRuO3SrRuO_3, the TpT_p values are shifted to lower temperatures by up to 6-8 K as compared to Tp≈140T_p\approx 140 K of the 5 nm thick reference SrRuO3SrRuO_3 film. In contrast, in the other type of bilayers, which are not in the pseudogap regime near TpT_p, only a smaller shift of up to ±\pm2 K is observed. These differences are discussed in terms of a proximity effect, where carriers from the YBa2Cu3OyYBa_2Cu_3O_y layer are injected into the SrRuO3SrRuO_3 layer and vice versa. We suggest that correlated electrons in the pseudogap regime of YBa2Cu3OyYBa_2Cu_3O_y are responsible for the observed large TpT_p shifts.Comment: 9 figure

    Transition Temperature of a Uniform Imperfect Bose Gas

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    We calculate the transition temperature of a uniform dilute Bose gas with repulsive interactions, using a known virial expansion of the equation of state. We find that the transition temperature is higher than that of an ideal gas, with a fractional increase K_0(na^3)^{1/6}, where n is the density and a is the S-wave scattering length, and K_0 is a constant given in the paper. This disagrees with all existing results, analytical or numerical. It agrees exactly in magnitude with a result due to Toyoda, but has the opposite sign.Comment: Email correspondence to [email protected] ; 2 pages using REVTe
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