RPMDrate: Bimolecular chemical reaction rates from ring polymer molecular dynamics

We present RPMDrate, a computer program for the calculation of gas phase bimolecular reaction rate coefficients using the ring polymer molecular dynamics (RPMD) method. The RPMD rate coefficient is calculated using the Bennett–Chandler method as a product of a static (centroid density quantum transition state theory (QTST) rate) and a dynamic (ring polymer transmission coefficient) factor. The computational procedure is general and can be used to treat bimolecular polyatomic reactions of any complexity in their full dimensionality. The program has been tested for the H+H2, H+CH4, OH+CH4 and H+C2H6 reactions.United States. Dept. of Energy (Office of Basic Energy Sciences under the Energy Frontier Research Center for Combustion Science (Grant No. DE-SC0001198))United States. Dept. of Energy (Energy Frontier Research Center for Combustion Science, Combustion Energy Research Fellowship)King Abdullah University of Science and Technology (Award No. KUS-I1-010-01

Efficient method for quantum calculations of molecule - molecule scattering properties in a magnetic field

We show that the cross sections for molecule - molecule collisions in the presence of an external field can be computed efficiently using a total angular momentum basis, defined either in the body-fixed frame or in the space-fixed coordinate system. This method allows for computations with much larger basis sets than previously possible. We present calculations for 15NH - 15NH collisions in a magnetic field. Our results support the conclusion of the previous study that the evaporative cooling of rotationally ground 15NH molecules in a magnetic trap has a prospect of success

A new approach to use of oral mucosa in reconstructive urethral surgery: micrografts

Introduction. Treatment of patients with complex urethral strictures is an actual problem of reconstructive urology. After multi-staged urethral surgery with multiple revisions the new reconstruction is limited by paucity of plastic material (for grafts and flaps). In-thing, new materials for urethral reconstruction (various auto, allo and xenografts) are still being developed in reconstructive urethral surgery.Purpose of the study. To study the possibility of using oral mucosa micrografts to form the urethral plate in the multi-stage surgery for patients with extended urethral strictures.Materials and methods. In the experimental study, male Wistar rats (22 individuals) weighing 300 – 400 g underwent a full-thickness skin wound after intramuscular sedation. We used the wound chamber (12 mm diameter) to exclude the wound contraction. The oral mucosa graft was harvested (6 mm in diameter). After pre-fabrication, the graft was minced to fragments < 1 mm2. Micrografts with fibrin-thrombin glue were applied to the wound. By day 45, the epithelial plate was excised for histological examination. In the clinical study, 4 patients with recurrent penile urethral strictures were treated with staged urethroplasty with urethral plate formation using oral mucosa micrografts. The average length of the stricture was 7.5 ± 1.2 cm (with extremely narrow and obliteration sites). The urethral plate was formed as the first stage. The preparation of the graft bed and oral mucosa grafts harvesting was carried out according to the standard procedure. Micrografts preparation and implantation was carried out as in experimental part of this study. After 6 months, neourethra tubularization was performed. The patients were evaluated every 3 months after the final stage of urethroplasty (uroflowmetry, ultrasound, X-ray, PROM-USS). The median follow-up was 9 months (3 – 18 months).Results. On day 15, in the experimental study, in 16 of 22 (72.7%) rats, the wound chambers had focal growth of the oral mucosa epithelium. On day 45, the wounds healed completely healed with oral mucosa. The final area of the plate was 78 ± 12 mm2. In the clinical study, 6 months after the first stage, all patients (n = 4) had a urethral plate covered with an oral mucosa epithelium without scar formation and sufficient for neurethra tubularization. All patients underwent urethral tubularization. After catheter removal, all men urinated. After 9 months (median follow-up, n = 3), the Qmax was 22.7 ± 4.2 ml/s, the post-void residual urine was 34.8 ± 2.2 ml, the total PROM-USS score was 7.4 ± 1.2, urethral lumen is preserved. All patients showed high satisfaction with the treatment.Conclusion. The oral mucosa micrografts showed good take in heterotopic transplantation (72.7%) with the formation of an epithelial layer on the wound surface. The final mucosal plate area 3 times exceeded the initial micrografts area. This initial clinical experience of using oral mucosa micrografts shows the new possibility of this technology in reconstructive urethral surgery, especially in patients with complex urethral strictures

Optical Identification of Four Hard X-ray Sources from the Swift All-Sky Survey

We present the results of our optical identifications of four hard X-ray sources from the Swift all-sky survey. We obtained optical spectra for each of the program objects with the 6-m BTA telescope (Special Astrophysical Observatory, Russian Academy of Sciences, Nizhnii Arkhyz), which allowed their nature to be established. Two sources (SWIFT J2237.2+6324} and SWIFT J2341.0+7645) are shown to belong to the class of cataclysmic variables (suspected polars or intermediate polars). The measured emission line width turns out to be fairly large (FWHM ~ 15-25 A), suggesting the presence of extended, rapidly rotating (v~400-600 km/s) accretion disks in the systems. Apart from line broadening, we have detected a change in the positions of the line centroids for SWIFT J2341.0+7645, which is most likely attributable to the orbital motion of the white dwarf in the binary system. The other two program objects (SWIFT J0003.3+2737 and SWIFT J0113.8+2515) are extragalactic in origin: the first is a Seyfert 2 galaxy and the second is a blazar at redshift z=1.594. Apart from the optical spectra, we provide the X-ray spectra for all sources in the 0.6-10 keV energy band obtained from XRT/Swift data.Comment: 9 pages, 6 figures, will be published in Astronomy Letters, 38, No.5, pp.281-289 (2012

The LOFT perspective on neutron star thermonuclear bursts

This is a White Paper in support of the mission concept of the Large Observatory for X-ray Timing (LOFT), proposed as a medium-sized ESA mission. We discuss the potential of LOFT for the study of thermonuclear X-ray bursts on accreting neutron stars. For a summary, we refer to the paper.Comment: White Paper in Support of the Mission Concept of the Large Observatory for X-ray Timin

Thin-Film Coatings of Mg-Al Spinel on Dielectric Substrates: Synthesis, Structure and Lattice Dynamics

Thin-film coatings based on Mg-Al spinel possess high thermal, chemical and radiation durability. Thus, they make it perspective for nano- and optoelectronic applications, where those factors are critical.Работа выполнена в рамках Госзадания ИГГ УрО РАН (№АААА-А18-118053090045-8) с использованием оборудования ЦКП "Геоаналитик", дооснащение которого поддержано грантом Минобрнауки РФ (№075-15-2021-680). Получение тонкопленочных покрытий выполнено в рамках грантов РНФ № 21-12-00392, РФФИ № 20-42-660012 и госзадания 2020-0059

Technical Design Report for the PANDA Solenoid and Dipole Spectrometer Magnets

This document is the Technical Design Report covering the two large spectrometer magnets of the PANDA detector set-up. It shows the conceptual design of the magnets and their anticipated performance. It precedes the tender and procurement of the magnets and, hence, is subject to possible modifications arising during this process.Comment: 10 pages, 14MB, accepted by FAIR STI in May 2009, editors: Inti Lehmann (chair), Andrea Bersani, Yuri Lobanov, Jost Luehning, Jerzy Smyrski, Technical Coordiantor: Lars Schmitt, Bernd Lewandowski (deputy), Spokespersons: Ulrich Wiedner, Paola Gianotti (deputy

Feasibility studies of the time-like proton electromagnetic form factor measurements with PANDA at FAIR

The possibility of measuring the proton electromagnetic form factors in the time-like region at FAIR with the \PANDA detector is discussed. Detailed simulations on signal efficiency for the annihilation of $\bar p +p$ into a lepton pair as well as for the most important background channels have been performed. It is shown that precision measurements of the differential cross section of the reaction $\bar p +p \to e^++ e^-$ can be obtained in a wide angular and kinematical range. The individual determination of the moduli of the electric and magnetic proton form factors will be possible up to a value of momentum transfer squared of $q^2\simeq 14$ (GeV/c)$^2$. The total $\bar p +p\to e^++e^-$ cross section will be measured up to $q^2\simeq 28$ (GeV/c)$^2$. The results obtained from simulated events are compared to the existing data. Sensitivity to the two photons exchange mechanism is also investigated.Comment: 12 pages, 4 tables, 8 figures Revised, added details on simulations, 4 tables, 9 figure

Feasibility studies of time-like proton electromagnetic form factors at PANDA at FAIR

Simulation results for future measurements of electromagnetic proton form factors at \PANDA (FAIR) within the PandaRoot software framework are reported. The statistical precision with which the proton form factors can be determined is estimated. The signal channel $\bar p p \to e^+ e^-$ is studied on the basis of two different but consistent procedures. The suppression of the main background channel, $\textit{i.e.}$ $\bar p p \to \pi^+ \pi^-$, is studied. Furthermore, the background versus signal efficiency, statistical and systematical uncertainties on the extracted proton form factors are evaluated using two different procedures. The results are consistent with those of a previous simulation study using an older, simplified framework. However, a slightly better precision is achieved in the PandaRoot study in a large range of momentum transfer, assuming the nominal beam conditions and detector performance

Physics Performance Report for PANDA: Strong Interaction Studies with Antiprotons

To study fundamental questions of hadron and nuclear physics in interactions of antiprotons with nucleons and nuclei, the universal PANDA detector will be built. Gluonic excitations, the physics of strange and charm quarks and nucleon structure studies will be performed with unprecedented accuracy thereby allowing high-precision tests of the strong interaction. The proposed PANDA detector is a state-of-the art internal target detector at the HESR at FAIR allowing the detection and identification of neutral and charged particles generated within the relevant angular and energy range. This report presents a summary of the physics accessible at PANDA and what performance can be expected.Comment: 216 page