Gap formation in helical edge states with magnetic impurities

Helical edge states appear at the surface of two dimensional topological insulators and are characterized by spin up traveling in one direction and the spin down traveling in the opposite direction. Such states are protected by time reversal symmetry and no backscattering due to scalar impurities can occur. However, magnetic impurities break time reversal symmetry and lead to backscattering. Often their presence is unintentional, but in some cases they are introduced into the sample to open up gaps in the spectrum. We investigate the influence of random impurities on helical edge states, specifically how the gap behaves in the realistic case of impurities having both a magnetic and a scalar component. It turns out that for a fixed magnetic contribution the gap closes when either the scalar component, or Fermi velocity is increased. We compare diagrammatic techniques in the self-consistent Born approximation to numerical calculations which yields good agreement. For experimentally relevant parameters we find that even moderate scalar components can be quite detrimental for the gap formation.Comment: 6 pages, 6 figure

Tailoring Chirp in Spin-Lasers

The usefulness of semiconductor lasers is often limited by the undesired frequency modulation, or chirp, a direct consequence of the intensity modulation and carrier dependence of the refractive index in the gain medium. In spin-lasers, realized by injecting, optically or electrically, spin-polarized carriers, we elucidate paths to tailoring chirp. We provide a generalized expression for chirp in spin-lasers and introduce modulation schemes that could simultaneously eliminate chirp and enhance the bandwidth, as compared to the conventional (spin-unpolarized) lasers.Comment: 4 pages, 3 figure

Minimum entropy production principle from a dynamical fluctuation law

The minimum entropy production principle provides an approximative variational characterization of close-to-equilibrium stationary states, both for macroscopic systems and for stochastic models. Analyzing the fluctuations of the empirical distribution of occupation times for a class of Markov processes, we identify the entropy production as the large deviation rate function, up to leading order when expanding around a detailed balance dynamics. In that way, the minimum entropy production principle is recognized as a consequence of the structure of dynamical fluctuations, and its approximate character gets an explanation. We also discuss the subtlety emerging when applying the principle to systems whose degrees of freedom change sign under kinematical time-reversal.Comment: 17 page

Dissociative electron attachment and vibrational excitation of CF3Cl\mathbf{CF_3Cl}: Effect of two vibrational modes revisited

We present a study of dissociative electron attachment and vibrational excitation processes in electron collisions with the CF$_3$Cl molecule. The calculations are based on the two-dimensional nuclear dynamics including the C-Cl symmetric stretch coordinate and the CF$_3$ symmetric deformation (umbrella) coordinate. The complex potential energy surfaces are calculated using the ab initio R-matrix method. The results for dissociative attachment and vibrational excitation of the umbrella mode agree quite well with experiment while the cross section for excitation of the C-Cl symmetric stretch vibrations is about a factor of three low as compared to experimental data.Comment: 24 pages, 7 figures, submitted to Physical Review

Minimally-invasive technologies in the treatment of choledocholithiasis complicated by biliary pancreatitis

Minimal invasive endoscopic technologies are used in the treatment of patients with biliary pancreatitis with complicated cholangitis and biliary sepsis. 56 patients were treated for the period 2014 - 2018, aged 65.5 ± 15.18 years. ERCP was performed in 31 (55,3%) patients, in 13 (23,2%) - surgical intervention was performed without contrast of extrahepatic bile ducts. Papillotomy in 52 cases (96,4%) was performed by string papilloma and in 4 (7,1%) - by needle. In all cases, subtotal papilloprotectomy was performed [1], supplemented by balloon sphincteroplasty. In the I group, the patients included patients with biliary pancreatitis clinic, in group II patients with clinic of biliary sepsis, in the III group patients with purulent cholangitis clinic, biliary sepsis and septic shock. In the 1st and 2nd groups of patients, mortality was not observed. In the 3rd group, 3 patients died (37,5%). The rest of the patients are discharged from the hospital in a satisfactory condition. A decrease in the level of markers of hepatitis cytolysis (AlAT, AsAT, GGTP, L-FABP) was observed during surgical procedures without ERCP, indicating the toxic effect of contrast on the liver parenchyma. L-FABP is a highly informative marker for hepatocyte cytolysis and can be used as a criterion for hepatic insufficiency and prognosis of biliary sepsis. The high efficiency of transpacillary endoscopic surgical techniques in the treatment of biliary pancreatitis and biliary sepsis was noted

Minimally-invasive technologies in the treatment of choledocholithiasis complicated by purulent cholangitis

Minimal invasive endoscopic technologies are used in the treatment of patients with choledocholithiasis with complicated cholangitis and biliary sepsis. 56 patients were treated for the period 2014 - 2018, aged 65.5 ± 15.18 years. ERCP was performed in 31 (55,3%) patients, in 13 (23,2%) - surgical intervention was performed without contrast of extrahepatic bile ducts. Papillotomy in 52 cases (96,4%) was performed by string papilloma and in 4 (7,1%) - by needle. In all cases, subtotal papilloprotectomy was performed [1], supplemented by balloon sphincteroplasty. In the I group, the patients included patients with acute cholangitis clinic, in group II patients with clinic of biliary sepsis, in the III group patients with purulent cholangitis clinic, biliary sepsis and septic shock. In the 1st and 2nd groups of patients, mortality was not observed. In the 3rd group, 3 patients died (37,5%). The rest of the patients are discharged from the hospital in a satisfactory condition. A decrease in the level of markers of hepatitis cytolysis (AlAT, AsAT, GGTP, L-FABP) was observed during surgical procedures without ERCP, indicating the toxic effect of contrast on the liver parenchyma. L-FABP is a highly informative marker for hepatocyte cytolysis and can be used as a criterion for hepatic insufficiency and prognosis of biliary sepsis. The high efficiency of transpacillary endoscopic surgical techniques in the treatment of cholangitis and biliary sepsis was noted

Fuel Summary for Peach Bottom Unit 1 High-Temperature Gas-Cooled Reactor Cores 1 and 2

This fuel summary report contains background and summary information for the Peach Bottom Unit 1, High-Temperature, Gas-Cooled Reactor Cores 1 and 2. This report contains detailed information about the fuel in the two cores, the Peach Bottom Unit 1 operating history, nuclear parameters, physical and chemical characteristics, and shipping and storage canister related data. The data in this document have been compiled from a large number of sources and are not qualified beyond the qualification of the source documents. This report is intended to provide an overview of the existing data pertaining to spent fuel management and point to pertinent reference source documents. For design applications, the original source documentation must be used. While all referenced sources are available as records or controlled documents at the Idaho National Engineering and Environmental Laboratory (INEEL), some of the sources were marked as informal or draft reports. This is noted where applicable. In some instances, source documents are not consistent. Where they are known, this document identifies those instances and provides clarification where possible. However, as stated above, this document has not been independently qualified and such clarifications are only included for information purposes. Some of the information in this summary is available in multiple source documents. An effort has been made to clearly identify at least one record document as the source for the information included in this report

Z-graded weak modules and regularity

It is proved that if any Z-graded weak module for vertex operator algebra V is completely reducible, then V is rational and C_2-cofinite. That is, V is regular. This gives a natural characterization of regular vertex operator algebras.Comment: 9 page

Origin Of The Far Off-Axis GRB171205A

We show that observed properties of the low luminosity GRB171205A and its afterglow, like those of most other low-luminosity (LL) gamma ray bursts (GRBs) associate with a supernova (SN), indicate that it is an ordinary SN-GRB, which was produced by inverse Compton scattering of glory light by a highly relativistic narrowly collimated jet ejected in a supernova explosion and viewed from a far off-axis angle. As such, VLA/VLBI follow-up radio observations of a superluminal displacement of its bright radio afterglow from its parent supernova, will be able to test clearly whether it is an ordinary SN-GRB viewed from far off-axis or it belongs to a distinct class of GRBs, which are different from ordinary GRBs, and cannot be explained by standard fireball models of GRBs as ordinary GRBsComment: 5 pages, 6 figures, updated data in Fig. 3, Corrected GRB angular distance used in Fig.