Detection of Giant Radio Pulses from the Pulsar PSR B0656+14

Giant pulses (GPs) have been detected from the pulsar PSR B0656+14. A pulse that is more intense than the average pulse by a factor of 120 is encountered approximately once in 3000 observed periods of the pulsar. The peak flux density of the strongest pulse, 120 Jy, is a factor of 630 higher than that of the average pulse. The GP energy exceeds the energy of the average pulse by up to a factor of 110, which is comparable to that for other known pulsars with GPs, including the Crab pulsar and the millisecond pulsar PSR B1937+21. The giant pulses are a factor of 6 narrower than the average pulse and are clustered at the head of the average pulse. PSR B0656+14 along with PSR B0031-07, PSR B1112+50, and PSR J1752+2359 belong to a group of pulsars that differ from previously known ones in which GPs have been detected without any extremely strong magnetic field on the light cylinder.Comment: 10 pages, 3 figures, 1 table; originally published in Russian in Pis'ma Astron. Zh., 2006, v.32, 650; translated by George Rudnitskii; the English version will be appear in Astronomy Letter

Detection of Giant Pulses from the Pulsar PSR B0031-07

Giant pulses have been detected from the pulsar PSR B0031-07. A pulse with an intensity higher than the intensity of the average pulse by a factor of 50 or more is encountered approximately once per 300 observed periods. The peak flux density of the strongest pulse is 530 Jy, which is a factor of 120 higher than the peak flux density of the average pulse. The giant pulses are a factor of 20 narrower than the integrated profile and are clustered about its center.Comment: 7 pages, 2 figures, to appear in: Pis'ma v Astronomicheskii Zhurnal, 2004, v.30, No.4, and will be translated as: Astronomy Letters, v.30, No.

Deformation of an Elastic Spherical Shell under the Pressure of Viscous Incompressible Fluid

The deformation of an elastic spherical shell under the pressure of viscous incompressible fluid is considered. Analytical formulas for calculating the components of normal and tangential deflections of the shell middle surface are obtained. A new mathematical model of an elastic spherical shell is offered on the basis of introduction of the Finite Element Method calculations. The comparison of the asymptotic and numerical results is performed

Instantaneous Radio Spectra of Giant Pulses from the Crab Pulsar from Decimeter to Decameter Wavelengths

The results of simultaneous multifrequency observations of giant radio pulses from the Crab pulsar, PSR B0531+21, at 23, 111, and 600 MHz are presented and analyzed. Giant pulses were detected at a frequency as low as 23 MHz for the first time. Of the 45 giant pulses detected at 23 MHz, 12 were identified with counterparts observed simultaneously at 600 MHz. Of the 128 giant pulses detected at 111 MHz, 21 were identified with counterparts observed simultaneously at 600 MHz. The spectral indices for the power-law frequency dependence of the giant-pulse energies are from -3.1 to -1.6. The mean spectral index is -2.7 +/- 0.1 and is the same for both frequency combinations (600-111 MHz and 600-23 MHz). The large scatter in the spectral indices of the individual pulses and the large number of unidentified giant pulses suggest that the spectra of the individual giant pulses do not actually follow a simple power law. The observed shapes of the giant pulses at all three frequencies are determined by scattering on interstellar plasma irregularities. The scatter broadening of the pulses and its frequency dependence were determined as tau_sc=20*(f/100)^(-3.5 +/- 0.1) ms, where the frequency f is in MHz.Comment: 13 pages, 1 figure, 1 table (originally published in Russian in Astronomicheskii Zhurnal, 2006, vol. 83, No. 7, pp. 630-637), translated by Georgii Rudnitski

Property (T)(T) for noncommutative universal lattices

We establish a new spectral criterion for Kazhdan's property $(T)$ which is applicable to a large class of discrete groups defined by generators and relations. As the main application, we prove property $(T)$ for the groups $EL_n(R)$, where $n\geq 3$ and $R$ is an arbitrary finitely generated associative ring. We also strengthen some of the results on property $(T)$ for Kac-Moody groups from a paper of Dymara and Januszkiewicz (Invent. Math 150 (2002)).Comment: 47 pages; final versio

СОВРЕМЕННЫЕ АНАЛИЗАТОРЫ ДЛЯ ОПРЕДЕЛЕНИЯ АЗОТА МЕТОДОМ КЬЕЛЬДАЛЯ

Current review covers all main stages of the quantitative determination of nitrogen by the Kjeldahl method: preparation and acid mineralization of samples, distillation, and various chemical and instrumental options for determining the ammonia released after the treatment of mineralization products with alkali. The review also describes the latest technical solutions used to improve and automate certain stages of analysis such as the usage of block and IR digesters that significantly increases the efficiency of sample mineralization and reduces its duration; the usage of automatic lifts for the mineralized samples, which reduces the work of the operator with the heavy and hot chemical samples as much as possible; the usage of autosampler, which provides the automatic transfer of mineralized samples to the distiller; the automation of distillation and titration processes; the use of software for processing the analysis results. The following technical characteristics of the basic components of automatic analyzers for the nitrogen determination by the Kjeldahl method are systematized: digesters, distillers, and titrators produced by such well-known companies as Buchi (Switzerland), C. Gerhardt, Behr Labor-Technik GmbH and FoodALYT GmbH (Germany), Foss Tecator (Denmark, Sweden), VELP Scientifica (Italy), J.P.Selecta (Spain), Hanon Instruments (China), OOO VPK Sibagropribor and OOO Vilitek (Russia). The data on the characteristics of the analyzers is also provided and includes the number and volume of test tubes (flasks), the time of mineralization, distillation and analysis, mass (volume) of the sample, and the lower limit of nitrogen detection.Keywords: Kjeldahl method, acid mineralization, distillation and quantitative determination of ammonia, automatic nitrogen analyzerDOI: http://dx.doi.org/10.15826/analitika.2019.23.2.002(Russian)E.A. Zauer, A.B. ErshovVolgograd State Technical University, pr. Lenina, 28, Volgograd, 400005,Russian FederationВ предлагаемом обзоре рассмотрены основные стадии определения азота методом Кьельдаля: подготовка и кислотная минерализация проб, отгонка и различные варианты (химические и инструментальные) определения аммиака, выделившегося после обработки продуктов минерализации щелочью. Приведены новые технические решения последних лет по совершенствованию и автоматизации отдельных стадий анализа: применение блочных и ИК-дигесторов, существенно повысивших эффективность минерализации образцов и снизивших ее длительность; использование автоматических подъемников минерализованных проб, максимально сокративших работу оператора с тяжелыми пробами и горячими химическими веществами; автосемплеров, обеспечивающих автоматическую передачу минерализованных проб в дистиллятор; автоматизация процессов дистилляции и титрования; использование программного обеспечения для обработки результатов анализа. Систематизированы технические характеристики основных узлов автоматических анализаторов для определения азота методом Кьельдаля – дигесторов, дистилляторов и титраторов, выпускаемых такими известными фирмами, как Buchi (Швейцария), C. Gerhardt, Behr Labor-Technik GmbH и FoodALYT GmbH (Германия), Foss Tecator (Дания, Швеция), VELP Scientifica (Италия), J.P.Selecta (Испания), Hanon Instruments (Китай), ООО ВПК Сибагроприбор и ООО «Вилитек» (Россия). Также приведены данные об основных аналитических характеристиках анализаторов: числе и объеме пробирок (колб), времени минерализации, дистилляции и анализа; массе (объеме) пробы, нижнем пределе обнаружения азота.Ключевые слова: метод Кьельдаля, кислотная минерализация, отгонка и определение аммиака, автоматический анализатор азотаDOI: http://dx.doi.org/10.15826/analitika.2019.23.2.00

Stable monopole and dyon solutions in the Einstein-Yang-Mills theory in asymptotically anti-de Sitter Space

A continuum of new monopole and dyon solutions in the Einstein-Yang-Mills theory in asymptotically anti-de Sitter space are found. They are regular everywhere and specified with their mass, and non-Abelian electric and magnetic charges. A class of monopole solutions which have no node in non-Abelian magnetic fields are shown to be stable against spherically symmetric linear perturbations.Comment: 9 pages with 5 figures. Revised version. To appear in Phys Rev Let