High pressure effects in fluorinated HgBa2Ca2Cu3O(8+d)

We have measured the pressure sensitivity of Tc in fluorinated HgBa2Ca2Cu3O(8+d) (Hg-1223) ceramic samples with different F contents, applying pressures up to 30 GPa. We obtained that Tc increases with increasing pressure, reaching different maximum values, depending on the F doping level, and decreases for a further increase of pressure. A new high Tc record (166 K +/- 1 K) was achieved by applying pressure (23 GPa) in a fluorinated Hg-1223 sample near the optimum doping level. Our results show that all our samples are at the optimal doping, and that fluorine incorporation decreases the crystallographic $a$-parameter concomitantly increasing the maximum attainable Tc. This effect reveals that the compression of the $a$ axes is one of the keys that controls the Tc of high temperature superconductors.Comment: 4 pages, 4 figures, submitted to Phys. Rev.

Optical echo in photonic crystals

The dynamics of photonic wavepacket in the effective oscillator potential is studied. The oscillator potential is constructed on a base of one dimensional photonic crystal with a period of unit cell adiabatically varied in space. The structure has a locally equidistant discrete spectrum. This leads to an echo effect, i.e. the periodical reconstruction of the packet shape. The effect can be observed in a nonlinear response of the system. Numerical estimations for porous-silicon based structures are presented for femtosecond Ti:Sapphire laser pump.Comment: 4 page

Positive parity pentaquark towers in large Nc QCD

We construct the complete set of positive parity pentaquarks, which correspond in the quark model to {\bar s} q^{Nc+1} states with one unit of orbital angular momentum L=1. In the large Nc limit they fall into the K=1/2 and K=3/2 irreps (towers) of the contracted SU(4)c symmetry. We derive predictions for the mass spectrum and the axial couplings of these states at leading order in 1/Nc. The strong decay width of the lowest-lying positive parity exotic state is of order O(1/Nc), such that this state is narrow in the large Nc limit. Replacing the antiquark with a heavy antiquark {\bar Q} q^{Nc+1}, the two towers become degenerate, split only by O(1/mQ) hyperfine interactions. We obtain predictions for the strong decay widths of heavy pentaquarks to ordinary baryons and heavy H(*)_{\bar Q} mesons at leading order in 1/Nc and 1/mQ.Comment: 21 pages, 2 figures, 5 table

Adaptive correction of thermal distortions of multichannel laser radiation

Results of the simulation of multichannel radiation propagation under conditions of thermal blooming are presented. The correction of nonlinear thermal distortion by means of the beam phase and amplitudephase control is considered. The results show the dependence of the correction effectiveness on the number of channels and on the precision of the reference beam phase retrieval. An additional increase in the effectiveness is possible by means of adjustment of amplification in the channels of the optical system, i.e., with the use of amplitude-phase control over the beam wavefront

Surgical Strategy in Patients with Complete Transposition of Internal Organs in Cancer of the Biliopancreatoduodenal Zone

Аim: to present two clinical cases of successful surgical treatment of patients with a combination of complete transposition of internal organs and cancer of the biliopancreatoduodenal zone.Key points. A 65-year-old man underwent gastropancreatoduodenal resection for cancer of the large duodenal papilla. In addition to the situs vicserum inversus, this patient revealed a special variant of vascular anatomy, namely: separate separation of the left and right hepatic arteries from the ventral trunk. A 70-year-old man, in addition to complete transposition of internal organs, had a combination of cancer of the terminal part of the common bile duct and heterotaxy syndrome in the form of polysplenia, aplasia of the hepatic segment of the inferior vena cava, agenesis of the dorsal pancreatic rudiment (“short” pancreas), intrapancreatic course of the right hepatic artery extending from the superior mesenteric arteries, rotational abnormalities of intestinal development. This patient underwent a total pancreatectomy. In both cases, the main difficulties in mobilizing the pancreatoduodenal complex arose due to anatomical disorientation and the absence of standard (familiar) topographic and anatomical landmarks for the surgeon.Conclusion. In all patients with tumors of the biliopancreatoduodenal zone, a detailed assessment of the vascular anatomy of this area is required before surgery, with the study of the course of the main visceral vessels and their large branches using multispiral computed tomography in vascular mode. If heterotaxy syndrome is suspected, additional examination is necessary to identify hidden developmental anomalies, which allows surgeons to be prepared for an unusual situation. Gastropancreatoduodenal resection or total pancreatectomy in situs viscerum inversus is a technically complex intervention and should be performed in large multidisciplinary medical institutions, and the operating team should have extensive experience in operations on the organs of the biliopancreatoduodenal zone

The soft and the hard pomerons in hadron elastic scattering at small t

We consider simple-pole descriptions of soft elastic scattering for pp, pbar p, pi+ p, pi- p, K+ p and K- p. We work at t and s small enough for rescatterings to be neglected, and allow for the presence of a hard pomeron. After building and discussing an exhaustive dataset, we show that simple poles provide an excellent description of the data in the region - 0.5 GeV^2 < t < -0.1 GeV^2, 6 GeV<sqrt(s)< 63 GeV. We show that new form factors have to be used, and get information on the trajectories of the soft and hard pomerons.Comment: 27 pages, 9 figures, LaTeX. A few typos fixed, and references correcte

Quasi-Two-Dimensional Dynamics of Plasmas and Fluids

In the lowest order of approximation quasi-twa-dimensional dynamics of planetary atmospheres and of plasmas in a magnetic field can be described by a common convective vortex equation, the Charney and Hasegawa-Mirna (CHM) equation. In contrast to the two-dimensional Navier-Stokes equation, the CHM equation admits "shielded vortex solutions" in a homogeneous limit and linear waves ("Rossby waves" in the planetary atmosphere and "drift waves" in plasmas) in the presence of inhomogeneity. Because of these properties, the nonlinear dynamics described by the CHM equation provide rich solutions which involve turbulent, coherent and wave behaviors. Bringing in non ideal effects such as resistivity makes the plasma equation significantly different from the atmospheric equation with such new effects as instability of the drift wave driven by the resistivity and density gradient. The model equation deviates from the CHM equation and becomes coupled with Maxwell equations. This article reviews the linear and nonlinear dynamics of the quasi-two-dimensional aspect of plasmas and planetary atmosphere starting from the introduction of the ideal model equation (CHM equation) and extending into the most recent progress in plasma turbulence.U. S. Department of Energy DE-FG05-80ET-53088Ministry of Education, Science and Culture of JapanFusion Research Cente

The Uses of Chiral Anomaly for Determination of the Number of Colors

The $N_c$-dependence of the vertices $PPP\gamma$, where $P$ is a pseudoscalar meson and $N_c$ is the number of colors, is analyzed with regard for the $N_c$-dependence of the quark charges. It is shown that the best processes for the determination of $N_c$ are the reactions $K\gamma \to K\pi$ and $\pi^pm\gamma\to\pi^\pm\eta$ as well as the decay \eta\ra\pi^+\pi^-\gamma. The measurement of the cross section \sigma(\pi^-\gamma\ra\pi^-\eta) at the VES facility at the IHEP agrees with the value $N_c=3$.Comment: 7 pages, 1 figure; accepted to Phys. Atom. Nucl., references adde