Identification and assessment of geohazards affecting pipelines and urban areas

The paper addresses methods and criteria of risk assessment associated with land subsidence threatening pipelines, buildings, and constructions. Currently, there are some practical issues relating to geohazards that should be taken into account while constructing a pipeline. The article provides comparison data on the effects of Spitak earthquake and the natural disaster in Neftegorsk in terms of geohazards impact on the pipeline systems. The suggested risk assessment procedure embraces a wide range of aspects: from soil properties to economic and management issues

Финансирование общедоступной медицинской помощи населению Российской Федерации: сохранять многоканальность или переходить на систему единого плательщика?

The subject of the research is the models of collection and consolidation (pooling) of resources for payment of public (free at the place of delivery) medical care to the population in developed countries and in the Russian Federation. The purpose of the study is to develop practical recommendations on the development of a system for financing medical guarantees for the population of the Russian Federation. The relevance of the study is due to the lack of resources to pay for public health care for the entire population in our country. The scientific novelty lies in the comparison of single-channel and multichannel pooling models used by developed countries in terms of their financial-economic and medico-social efficiency with the conclusion about a higher level of costs of the multichannel model with a comparable level of coverage with medical services of the population and indicators of its health compared to the model single payer. The research methodology is based on the use of complex, statistical, comparative and retrospective analyzes. It was concluded that the use of a multichannel pooling model in the financing of healthcare in the Russian Federation with the participation of competing insurers and the use of different channels of budgetary financing for different groups of the population is an important reason for the low efficiency of the Russian healthcare system. The prospect of further research is in the formation of a scientific and methodological justification for replacing the multichannel pooling model, which has historically developed in healthcare in Russia, with a single-channel model of a single payer represented by the Federal Compulsory Medical Insurance Fund (hereinafter- CMIF).Предмет исследования — модели сбора и консолидации (пулинга) ресурсов для оплаты общедоступной (бесплатной по месту оказания) медицинской помощи населению в развитых странах и в Российской Федерации. Цель исследования — разработка практических рекомендаций по развитию системы финансирования медицинских гарантий населению Российской Федерации. Актуальность исследования обусловлена дефицитом ресурсов для оплаты общедоступной медицинской помощи всему населению в нашей стране. Научная новизна заключается в проведенном сравнении используемых развитыми странами одноканальной и многоканальной моделей пулинга с точки зрения их финансово-экономической и медико-социальной эффективности с выводом о более высоком уровне расходов многоканальной модели при сопоставимом уровне охвата медицинскими услугами населения и показателях его здоровья по сравнению с моделью единого плательщика. Методология исследования основана на использовании комплексного, статистического, сравнительного и ретроспективного анализов. Сделан вывод: использование в финансировании здравоохранения Российской Федерации многоканальной модели пулинга с участием конкурирующих страховщиков и разных каналов бюджетного финансирования для различных групп населения представляется важной причиной низкой эффективности российской системы здравоохранения. Перспектива дальнейших исследований — в формировании научно-методологического обоснования замены исторически сложившейся в здравоохранении России многоканальной модели пулинга на одноканальную модель единого плательщика в лице Федерального фонда обязательного медицинского страхования (далее — ФФОМС)

On the Convergence of Kergin and Hakopian Interpolants at Leja Sequences for the Disk

We prove that Kergin interpolation polynomials and Hakopian interpolation polynomials at the points of a Leja sequence for the unit disk $D$ of a sufficiently smooth function $f$ in a neighbourhood of $D$ converge uniformly to $f$ on $D$. Moreover, when $f$ is $C^\infty$ on $D$, all the derivatives of the interpolation polynomials converge uniformly to the corresponding derivatives of $f$

Soft X-ray harmonic comb from relativistic electron spikes

We demonstrate a new high-order harmonic generation mechanism reaching the `water window' spectral region in experiments with multi-terawatt femtosecond lasers irradiating gas jets. A few hundred harmonic orders are resolved, giving uJ/sr pulses. Harmonics are collectively emitted by an oscillating electron spike formed at the joint of the boundaries of a cavity and bow wave created by a relativistically self-focusing laser in underdense plasma. The spike sharpness and stability are explained by catastrophe theory. The mechanism is corroborated by particle-in-cell simulations

X-ray harmonic comb from relativistic electron spikes

X-ray devices are far superior to optical ones for providing nanometre spatial and attosecond temporal resolutions. Such resolution is indispensable in biology, medicine, physics, material sciences, and their applications. A bright ultrafast coherent X-ray source is highly desirable, for example, for the diffractive imaging of individual large molecules, viruses, or cells. Here we demonstrate experimentally a new compact X-ray source involving high-order harmonics produced by a relativistic-irradiance femtosecond laser in a gas target. In our first implementation using a 9 Terawatt laser, coherent soft X-rays are emitted with a comb-like spectrum reaching the 'water window' range. The generation mechanism is robust being based on phenomena inherent in relativistic laser plasmas: self-focusing, nonlinear wave generation accompanied by electron density singularities, and collective radiation by a compact electric charge. The formation of singularities (electron density spikes) is described by the elegant mathematical catastrophe theory, which explains sudden changes in various complex systems, from physics to social sciences. The new X-ray source has advantageous scalings, as the maximum harmonic order is proportional to the cube of the laser amplitude enhanced by relativistic self-focusing in plasma. This allows straightforward extension of the coherent X-ray generation to the keV and tens of keV spectral regions. The implemented X-ray source is remarkably easily accessible: the requirements for the laser can be met in a university-scale laboratory, the gas jet is a replenishable debris-free target, and the harmonics emanate directly from the gas jet without additional devices. Our results open the way to a compact coherent ultrashort brilliant X-ray source with single shot and high-repetition rate capabilities, suitable for numerous applications and diagnostics in many research fields

High order harmonics from relativistic electron spikes

A new regime of relativistic high-order harmonic generation is discovered [Phys. Rev. Lett. 108, 135004 (2012)]. Multi-terawatt relativistic-irradiance (>1018 W/cm2) femtosecond (~30-50 fs) lasers focused to underdense (few×1019 cm-3) plasma formed in gas jet targets produce comb-like spectra with hundreds of even and odd harmonic orders reaching the photon energy of 360 eV, including the 'water window' spectral range. Harmonics are generated by either linearly or circularly polarized pulses from the J-KAREN (KPSI, JAEA) and Astra Gemini (CLF, RAL, UK) lasers. The photon number scalability has been demonstrated with a 120 TW laser producing 40 μJ/sr per harmonic at 120 eV. The experimental results are explained using particle-in-cell (PIC) simulations and catastrophe theory. A new mechanism of harmonic generation by sharp, structurally stable, oscillating electron spikes at the joint of boundaries of wake and bow waves excited by a laser pulse is introduced. In this paper detailed descriptions of the experiments, simulations and model are provided and new features are shown, including data obtained with a two-channel spectrograph, harmonic generation by circularly polarized laser pulses and angular distribution

Parental growth media of Siberian diamonds - relation to kimberlites

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Growth medium and carbon source of unusual rounded diamonds from alluvial placers of the North-East of Siberian Platform

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