Transformation of internal solitary waves at the "deep" and "shallow" shelf: satellite observations and laboratory experiment

An interaction of internal solitary waves with the shelf edge in the time periods related to the presence of a pronounced seasonal pycnocline in the Red Sea and in the Alboran Sea is analysed via satellite photos and SAR images. Laboratory data on transformation of a solitary wave of depression while passing along the transverse bottom step were obtained in a tank with a two-layer stratified fluid. The certain difference between two characteristic types of hydrophysical phenomena was revealed both in the field observations and in experiments. The hydrological conditions for these two processes were named the "deep" and the "shallow" shelf respectively. The first one provides the generation of the secondary periodic short internal waves – "runaway" edge waves – due to change in the polarity of a part of a soliton approaching the shelf normally. Another one causes a periodic shear flow in the upper quasi-homogeneous water layer with the period of incident solitary wave. The strength of the revealed mechanisms depends on the thickness of the water layer between the pycnocline and the shelf bottom as well as on the amplitude of the incident solitary wave

ИССЛЕДОВАНИЕ ВЛИЯНИЯ СТРУКТУРНОГО СОСТОЯНИЯ РАСПЛАВА НА КРИСТАЛЛИЧЕСКОЕ СТРОЕНИЕ И МЕХАНИЧЕСКИЕ СВОЙСТВА ФАЗ СПЛАВА AL-50 МАС.%SN МЕТОДОМ НАНОИНДЕНТИРОВАНИЯ

Nanoindentation is used to measure Young's modulus, the hardness, the plasticity, and the yield strength of the phases in Al-50 wt % Sn alloy samples prepared by a traditional method and using liquid-state homogenization. The effect of an increase in the cooling rate by an order of magnitude and alloying with 0.06 wt % Ti or 1 wt % Zr on the mechanical properties of the phases in the Al-50 wt % Sn alloy is studied. The most substantial effect on Young's modulus of the phases in the Al-50 wt % Sn alloy is found to be exerted by the homogenization of the metallic liquid and the introduction of zirconium in the alloy melt: the metal forming of an ingot is improved substantially. © 2013 Pleiades Publishing, Ltd

Особливості взаємодії 3-(2-амінофеніл)-6-R-1,2,4-триазин-5(2H)-онів та циклічних ангідридів несиметричних дикарбонових кислот

The peculiarities of the reaction between 3-(2-aminophenyl)-6-R-1,2,4-triazin-5(2H)-ones and cyclic anhydrides of non-symmetric (2-methylsuccinic, 2-phenylsuccinic and camphoric) acids have been described in the present article. The influence of electronic and steric effects of substituents in the anhydride molecule on cyclisation processes has been discussed. The results have shown that the interaction of 3-(2-aminophenyl)-6-R-1,2,4-triazin- 5(2H)-ones mentioned above with 2-methylsuccinic and 2-phenylsuccinic acid anhydrides proceeded non-selectively and yielded the mixtures of 2-R1-3-(2-oxo-3-R-2H-[1,2,4]triazino[2,3-c]quinazoline-6-yl)propanoic acids and 1-(2-(5-oxo-6-R-2,5-dihydro-1,2,4-triazin-3-yl)phenyl)-3-R1-pyrrolidine-2,5-diones. It has been found that low regioselectivity of the acylation process may be explained by insignificant electronic effects of substituents (of the methyl and phenyl fragment) in position 2 of the anhydride molecule on the electrophilic reaction centre. It has been also determined that the reaction between 3-(2-aminophenyl)-6-R-1,2,4-triazin-5(2H)-ones and camphoric anhydride proceeds regioselectively and yielded 1,2,2-trimethyl-3-(3-R-2-oxo-2H-[1,2,4]triazino[2,3-c]quinazolin- 6-yl)cyclopentan-1-carboxylic acids. Regioselectivity of the interaction mentioned above may be explained by the steric effect of the methyl group. Identity of compounds has been proven by LC-MS, the structure has been determined via a set of characteristic signals in 1H NMR, 13C NMR spectra and position of cross peaks in the correlation HSQC-experiment. Mass spectra of the compounds synthesized have been also studied, the principal directions of the molecule fragmentation have been described. The structure of 1,2,2-trimethyl-3-(3-methyl- 2-oxo-2H-[1,2,4]triazino[2,3-c]quinazolin-6-yl)cyclopentane-1-carboxylic acid has been proven by X-ray analysis.Описаны особенности реакции между 3-(2-аминофенил)-6-R-1,2,4-триазин-5(2H)-онами и ангидридами несимметричных дикарбоновых кислот (2-метилянтарной, 2-фенилянтарной и камфорной) кислот. Проведено обсуждение влияния электронных и стерических эффектов заместителей на процессы цик- лизации. Результаты показали, что взаимодействие приведенных выше 3-(2-аминофенил)-6-R-1,2,4- триазин-5(2H)-онов с ангидридами 2-метилянтарной и 2-фенилянтарной кислот протекало не региоселективно с образованием смесей 2-R 1-3-(2-оксо-3-R-2H-[1,2,4]триазино[2,3-c]хиназолин-6-ил)про- пановых кислот и 1-(2-(5-оксо-6-R-2,5-дигидро-1,2,4триазин-3-ил)фенил)-3-R1-пиролидин-2,5-дионов. По- казано, что низкая региоселективность процесса ацилирования может быть объяснена незначительными электронными эффектами заместителей (метильного и фенильного фрагмента) в положении 2 молекулы ангидрида на электрофильный реакционный центр. Также установлено, что реакция между 3-(2-аминофенил)-6-R-1,2,4-триазин-5(2H)-онами и ангидридом камфорной кислоты протекает регио- селективно и приводит к образованию 1,2,2-триметил-3-(3-R-2-оксо-2H-[1,2,4]триазино[2,3-c]хиназолин- 6-ил)циклопентан-1-карбоновых кислот. Селективность реакции в данном случае может быть объяснена стерическим эффектом метильной группы. Индивидуальность соединений подтверждена ме- тодами LC-MS, структуру установлено по положению характеристических сигналов в 1H ЯМР и 13С ЯМР-спектрах и по положению кросс-пиков в корреляционном HSQC-эксперименте. Также были иссле- дованы масс-спектры синтезированных соединений и описаны основные направления фрагментации молекулярных ионов. Структуру 1,2,2-триметил-3-(3-метил-2-оксо-2H-[1,2,4]триазино[2,3-c]хиназолин- 6-ил)циклопентан-1-карбоновой кислоты было доказано с помощью рентгеноструктурного анализа.Описані особливості реакції між 3-(2-амінофеніл)-6-R-1,2,4-триазин-5(2H)-онами з ангідридами несимет- ричних дикарбонових кислот (2-метилбурштинової, 2-фенілбурштинової та камфорної) кислот. Обго- ворено вплив електронних та стеричних ефектів замісника у молекулі ангідриду на процеси циклізації. Результати показали, що взаємодія наведених вище 3-(2-амінофеніл)-6-R-1,2,4-триазин-5(2H)-онів з ангідридами 2-метилбурштинової та 2-фенілбурштинової кислот перебігала нерегіоселективно з утворенням суміші 2-R1-3-(2-оксо-3-R-2H-[1,2,4]триазино[2,3-c]хіназолін-6-іл)пропанових кислот та 1-(2- (5-оксо-6-R-2,5-дигідро-1,2,4триазин-3-іл)феніл)-3-R1-піролідин-2,5-діонів. Показано, що низька регіосе- лективність процесу ацилювання може бути пояснена незначними електронними ефектами замісників (метального та фенільного фрагменту) у положенні 2 молекули ангідриду на електрофільний реакційний центр. Також встановлено, що реакція між 3-(2-амінофеніл)-6-R-1,2,4-триазин-5(2H)-онами та ангідридом камфорної кислоти перебігає регіоселективно та приводить до утворення 1,2,2-триметил-3-(3- R-2-оксо-2H-[1,2,4]триазино[2,3-c]хіназолін-6-іл)циклопентан-1-карбонових кислот. Селективність за- значеної вище реакції може бути пояснена стеричними ефектами метальної групи. Індивідуальність сполук підтверджена методом LC-MS, структуру встановлено за положенням характеристичних сигналів у 1H ЯМР та 13С ЯМР-спектрах та за положенням крос-піків у кореляційному HSQC-експерименті. Також були досліджені мас-спектри синтезованих сполук та описані основні напрямки фрагментації молекулярних іонів. Структуру 1,2,2-триметил-3-(3-метил-2-оксо-2H-[1,2,4]триазино[2,3-c]хіназолін-6-іл) циклопентан-1-карбонової кислоти було доведено за допомогою рентгеноструктурного дослідження

Non-Oberbeck-Boussinesq effects in turbulent thermal convection in ethane close to the critical point

As shown in earlier work (Ahlers et al., J. Fluid Mech. 569, p.409 (2006)), non-Oberbeck Boussinesq (NOB) corrections to the center temperature in turbulent Rayleigh-Benard convection in water and also in glycerol are governed by the temperature dependences of the kinematic viscosity and the thermal diffusion coefficient. If the working fluid is ethane close to the critical point the origin of non-Oberbeck-Boussinesq corrections is very different, as will be shown in the present paper. Namely, the main origin of NOB corrections then lies in the strong temperature dependence of the isobaric thermal expansion coefficient \beta(T). More precisely, it is the nonlinear T-dependence of the density \rho(T) in the buoyancy force which causes another type of NOB effect. We demonstrate that through a combination of experimental, numerical, and theoretical work, the latter in the framework of the extended Prandtl-Blasius boundary layer theory developed in Ahlers et al., J. Fluid Mech. 569, p.409 (2006). The latter comes to its limits, if the temperature dependence of the thermal expension coefficient \beta(T) is significant.Comment: 18 pages, 15 figures, 3 table

2,3,4,6,7,8,9,10-Octa­hydro­pyrimido[1,2-a]azepin-1-ium 2-cyano-1-(2,6-dimethylanilino)-2-(phenyl­sulfonyl)ethenethiol­ate

In the title compound, C9H17N2 +·C17H15N2O2S2 −, the Csp 2—N bonds in the tetra­hydro­pyrimidine ring of the cation are delocalized. The negative charge is localized on the S atom of the thione group. Cations and anions are linked by N—H⋯S inter­molecular hydrogen bonds

The transcription factor dFOXO controls the expression of insulin pathway genes and lipids content under heat stress in <i>Drosophila melanogaster</i>

The insulin/insulin-like growth factor signaling (IIS) pathway is one of the key elements in an organism’s response to unfavourable conditions. The deep homology of this pathway and its evolutionary conservative role in controlling the carbohydrate and lipid metabolism make it possible to use Drosophila melanogaster for studying its functioning. To identify the properties of interaction of two key IIS pathway components under heat stress in D. melanogaster (the forkhead box O transcription factor (dFOXO) and insulin-like peptide 6 (DILP6), which intermediates the dFOXO signal sent from the fat body to the insulin-producing cells of the brain where DILPs1–5 are synthesized), we analysed the expression of the genes dilp6, dfoxo and insulin-like receptor gene (dInR) in females of strains carrying the hypomorphic mutation dilp641 and hypofunctional mutation foxoBG01018. We found that neither mutation influenced dfoxo expression and its uprise under short-term heat stress, but both of them disrupted the stress response of the dilp6 and dInR genes. To reveal the role of identified disruptions in metabolism control and feeding behaviour, we analysed the effect of the dilp641 and foxoBG01018 mutations on total lipids content and capillary feeding intensity in imago under normal conditions and under short-term heat stress. Both mutations caused an increase in these parameters under normal conditions and prevented decrease in total lipids content following heat stress observed in the control strain. In mutants, feeding intensity was increased under normal conditions; and decreased following short-term heat stress in all studied strains for the first 24 h of observation, and in dilp641 strain, for 48 h. Thus, we may conclude that dFOXO takes part in regulating the IIS pathway response to heat stress as well as the changes in lipids content caused by heat stress, and this regulation is mediated by DILP6. At the same time, the feeding behaviour of imago might be controlled by dFOXO and DILP6 under normal conditions, but not under heat stress

Micro-CT-based analysis of fibre-reinforced composites:Applications

The paper presents an overview of cases in which the analysis of the internal structure and mechanical properties of fibre reinforced composites is performed based on the micro-computed X-ray tomography (micro-CT) reconstruction of the composite reinforcement geometry. In all the cases, the analysis relies on structure tensor-based algorithms for quantification of the micro-CT image, implemented in VoxTex software

Isolation of two strains of West Nile virus during an outbreak in southern Russia, 1999.

From July to September 1999, a widespread outbreak of meningoencephalitis associated with West Nile virus (Flavivirus, Flaviviridae) occurred in southern Russia, with hundreds of cases and dozens of deaths. Two strains of West Nile virus isolated from patient serum and brain-tissue samples reacted in hemagglutination-inhibition and neutralization tests with patients' convalescent-phase sera and immune ascites fluid from other strains of West Nile virus

ВЛИЯНИЕ МИКРОГЕТЕРОГЕННОСТИ И УСЛОВИЙ КРИСТАЛЛИЗАЦИИ РАСПЛАВА Al–50%Sn НА МЕХАНИЧЕСКИЕ СВОЙСТВА ФАЗОВЫХ СОСТАВЛЯЮЩИХ СЛИТКА

There were determined regularities of the influence of microheterogeneity and crystallization conditions of Al–50wt.%Sn melt on the mechanical properties of ingot phase constituents (Young modulus and nanohardness). The measurements of given characteristics were performed by means of nanoindentation method. Results of investigations allowed revealing the mechanism of microheterogeneity and crystallization conditions of melt on the ingot machinability by metal forming.Установлены закономерности влияния микрогетерогенности и условий кристаллизации расплава Al–50мас.%Sn на механические свойства фазовых составляющих слитка: модуль Юнга и нанотвердость. Измерения данных характеристик проведены методом наноиндентирования. Результаты исследования позволяют выяснить механизм воздействия микрогетерогенности и условий кристаллизации расплава на обрабатываемость слитка давлением

Radiative corrections to the cross section of e−+p→ν+ne^-+p\to \nu+n and the crossed processes

Born cross section and the radiative corrections to its lowest order are considered in the frame work of QED with structureless nucleons including the emission of virtual and real photons. Result is generalized to take into account radiative corrections in higher orders of perturbation theory in the leading and next-to leading logarithmic approximation. Crossing processes are considered in the leading approximation.Comment: 11 pages, 1 figur