Evaluation of specific heat for superfluid helium between 0 - 2.1 K based on nonlinear theory

The specific heat of liquid helium was calculated theoretically in the Landau theory. The results deviate from experimental data in the temperature region of 1.3 - 2.1 K. Many theorists subsequently improved the results of the Landau theory by applying temperature dependence of the elementary excitation energy. As well known, many-body system has a total energy of Galilean covariant form. Therefore, the total energy of liquid helium has a nonlinear form for the number distribution function. The function form can be determined using the excitation energy at zero temperature and the latent heat per helium atom at zero temperature. The nonlinear form produces new temperature dependence for the excitation energy from Bose condensate. We evaluate the specific heat using iteration method. The calculation results of the second iteration show good agreement with the experimental data in the temperature region of 0 - 2.1 K, where we have only used the elementary excitation energy at 1.1 K.Comment: 6 pages, 3 figures, submitted to Journal of Physics: Conference Serie

RUSSIAN FARM ENTERPRISE PERFORMANCE AND RESTRUCTURING: A DEBT PROBLEM OR A PROFITABILITY PROBLEM?

Farm Management,

Differential elastic scattering cross sections for 54.9eV positrons incident on helium

Absolute differential elastic scattering cross sections measured with the 3-m, high resolution, time-of-flight spectrometer are presented for 54.9eV positrons incident on He. Five point moving average differential cross sections are plotted against average scattering angles which range from 14 to 36 deg. Also the averages of five differential cross sections which have adjacent values of scattering angle are plotted versus the corresponding averages of the scattering angles. The curve fitted to these data is shaped like the theoretical curve but has its minimum and its maximum at scattering angles that are about 4 deg higher and 15 deg lower respectively than predicted by theory

FIP Bias Evolution in a Decaying Active Region

Solar coronal plasma composition is typically characterized by first ionization potential (FIP) bias. Using spectra obtained by Hinode's EUV Imaging Spectrometer (EIS) instrument, we present a series of large-scale, spatially resolved composition maps of active region (AR) 11389. The composition maps show how FIP bias evolves within the decaying AR from 2012 January 4-6. Globally, FIP bias decreases throughout the AR. We analyzed areas of significant plasma composition changes within the decaying AR and found that small-scale evolution in the photospheric magnetic field is closely linked to the FIP bias evolution observed in the corona. During the AR's decay phase, small bipoles emerging within supergranular cells reconnect with the pre-existing AR field, creating a pathway along which photospheric and coronal plasmas can mix. The mixing time scales are shorter than those of plasma enrichment processes. Eruptive activity also results in shifting the FIP bias closer to photospheric in the affected areas. Finally, the FIP bias still remains dominantly coronal only in a part of the AR's high-flux density core. We conclude that in the decay phase of an AR's lifetime, the FIP bias is becoming increasingly modulated by episodes of small-scale flux emergence, i.e. decreasing the AR's overall FIP bias. Our results show that magnetic field evolution plays an important role in compositional changes during AR development, revealing a more complex relationship than expected from previous well-known Skylab results showing that FIP bias increases almost linearly with age in young ARs (Widing $\&$ Feldman, 2001, ApJ, 555, 426)

An Optimal Linear Time Algorithm for Quasi-Monotonic Segmentation

Monotonicity is a simple yet significant qualitative characteristic. We consider the problem of segmenting a sequence in up to K segments. We want segments to be as monotonic as possible and to alternate signs. We propose a quality metric for this problem using the l_inf norm, and we present an optimal linear time algorithm based on novel formalism. Moreover, given a precomputation in time O(n log n) consisting of a labeling of all extrema, we compute any optimal segmentation in constant time. We compare experimentally its performance to two piecewise linear segmentation heuristics (top-down and bottom-up). We show that our algorithm is faster and more accurate. Applications include pattern recognition and qualitative modeling.Comment: This is the extended version of our ICDM'05 paper (arXiv:cs/0702142

Phenomenology of Dirac Neutrinogenesis in Split Supersymmetry

In Split Supersymmetry scenarios the possibility of having a very heavy gravitino opens the door to alleviate or completely solve the worrisome "gravitino problem'' in the context of supersymmetric baryogenesis models. Here we assume that the gravitino may indeed be heavy and that Majorana masses for neutrinos are forbidden as well as direct Higgs Yukawa couplings between left and right handed neutrinos. We investigate the viability of the mechansim known as Dirac leptogenesis (or neutrinogenesis), both in solving the baryogenesis puzzle and explaining the observed neutrino sector phenomenology. To successfully address these issues, the scenario requires the introduction of at least two new heavy fields. If a hierarchy among these new fields is introduced, and some reasonable stipulations are made on the couplings that appear in the superpotential, it becomes a generic feature to obtain the observed large lepton mixing angles. We show that in this case, it is possible simultaneously to obtain both the correct neutrino phenomenology and enough baryon number, making thermal Dirac neutrinogenesis viable. However, due to cosmological constraints, its ability to satisfy these constraints depends nontrivially on model parameters of the overall theory, particularly the gravitino mass. Split supersymmetry with m_{3/2} between 10^{5} and 10^{10} GeV emerges as a "natural habitat" for thermal Dirac neutrinogenesis.Comment: 37 pages, 8 figure