The flattenings of the layers of rotating planets and satellites deformed by a tidal potential     

Hugo A. Folonier  Sylvio Ferraz-Mello  Konstantin V. Kholshevnikov 《Celestial Mechanics and Dynamical Astronomy》2015,122(2):183-198

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Existence of a class of irregular bodies with a higher convergence rate of Laplace series for the gravitational potential     

Konstantin V. Kholshevnikov  Vakhit Sh. Shaidulin 《Celestial Mechanics and Dynamical Astronomy》2015,122(4):391-403

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Local polynomials for data detrending and interpolation in the presence of barriers     

Alexander Gribov  Konstantin Krivoruchko 《Stochastic Environmental Research and Risk Assessment (SERRA)》2011,25(8):1057-1063

We discuss features of local polynomial interpolation (LPI), focusing on the problem with unstable solutions of the LPI system of linear equations. We develop a new diagnostic based on condition number values. Also, a variant of Tikhonov regularization is proposed, which allows the production of continuous predictions and prediction standard errors nearly everywhere in the data domain. This variant of LPI can be used in the presence of barriers defined by polylines. LPI model is a good candidate for real time automatic mapping of the data regularly collected from the environmental monitoring networks. We illustrate the LPI usage with both simulated data and real data.  相似文献   

Mapping of underground cavities by the passive seismic standing waves method: the case study of Barsukovskaya cave (Novosibirsk region,Russia)     

Konstantin V. Fedin  Yury I. Kolesnikov  Luckymore Ngomayezwe 《Geophysical Prospecting》2021,69(1):167-179

This article presents the results of mapping a karst cave by the passive seismic standing waves method. Barsukovskaya cave is located about 100 km southeast of the city of Novosibirsk (Russia). The total length of the cave's passages and grottoes is estimated at about 200 m, the maximum depth from the earth's surface is about 19 m. The method for studying underground cavities used is based on the effect of the generation of standing waves by microtremor in the space between the earth's surface and the cave roof. The accumulation of amplitude spectra of a large number of microtremor records makes it possible to determine the frequencies of the first few modes of these waves. Areal passive seismic survey on the earth's surface above the cave made it possible to construct a map of the lowest mode frequency distribution over the cave roof. Since no standing waves were observed at other points, this map reflects the cave structure in plan, which confirms the comparison with the cave diagram drawn up earlier by one of the speleologists. A schematic map of the depth of the cave roof was constructed using the longitudinal wave velocity V_p = 3120 m/s determined by the rock samples selected near the entrance to the cave. This map at a qualitative level also agrees with the data of speleologists, which indicate that the cave, on average, gradually becomes deeper from the entrance to its dead‐end branches. The shallower depths in comparison with the data of speleologists are apparently explained by a very low estimate of the velocity determined from a rock sample taken near the entrance to the cave. The reliability of the obtained cave mapping results is confirmed by the numerical simulation results using the finite‐element method.  相似文献   

Variscan potassic dyke magmatism of durbachitic affinity at the southern end of the Bohemian Massif (Lower Austria)     

Helga Zeitlhofer  Bernhard Grasemann  Konstantin Petrakakis 《International Journal of Earth Sciences》2016,105(4):1175-1197

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Micro-mechanical failure analysis of wet granular matter   总被引：1，自引：1，他引：0  

Konstantin?MelnikovEmail author  Falk?K.?Wittel  Hans?J.?Herrmann 《Acta Geotechnica》2016,11(3):539-548

We employ a novel fluid–particle model to study the shearing behavior of granular soils under different saturation levels, ranging from the dry material via the capillary bridge regime to higher saturation levels with percolating clusters. The full complexity of possible liquid morphologies Scheel et al. (Nat Mater 7(3):189–193, 2008. doi: 10.1038/nmat2117) is taken into account, implying the formation of isolated arbitrary-sized liquid clusters with individual Laplace pressures that evolve by liquid exchange via films on the grain surface Melnikov et al. (Phys Rev E 92(022):206, 2015. doi: 10.1103/PhysRevE.92.022206). Liquid clusters can grow in size, shrink, merge and split, depending on local conditions, changes of accessible liquid and the pore space morphology determined by the granular phase. This phase is represented by a discrete particle model based on contact dynamics Brendel et al. (Contact dynamics for beginners. Wiley-VCH, Weinheim, 2005. doi: 10.1002/352760362X.ch14), where capillary forces exerted from a liquid phase add to the motion of spherical particles. We study the macroscopic response of the system due to an external compression force at various liquid contents with the help of triaxial shear tests. Additionally, the change in liquid cluster distributions during the compression due to the deformation of the pore space is evaluated close to the critical load.  相似文献   

The Revised Sunspot Record in Comparison to Cosmogenic Radionuclide-Based Solar Activity Reconstructions     

Raimund Muscheler  Florian Adolphi  Konstantin Herbst  Andreas Nilsson 《Solar physics》2016,291(9-10):3025-3043

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The appraisal of surface orbital vibrators with buried geophone array for permanent reservoir monitoring     

Sinem Yavuz  Roman Pevzner  Sofya Popik  Konstantin Tertyshnikov  Todd Wood  Michelle C. Robertson  Julia Correa  Barry Freifeld 《Geophysical Prospecting》2022,70(1):108-120

Time-lapse seismic is one of the main methods for monitoring changes in reservoir conditions caused by production or injection of fluids. One approach to time-lapse seismic is through permanent reservoir monitoring, whereby seismic sources and/or receivers are permanently deployed. Permanent reservoir monitoring can offer a more cost-effective and environmentally friendly solution than traditional campaign-based surveys that rely on temporarily deployed equipment while facilitating more frequent measurements. At the CO2CRC Otway Project, surface orbital vibrators were coupled to a buried geophone array to form a permanent reservoir monitoring system. These are fixed position seismic sources that provide both P and S waves using induction motor-driven eccentric masses. After an initial injection of CO₂ in February 2016, five months of continuous seismic data were acquired, and reflection imaging was used to assess the system performance. Analysis of the data showed the effects of weather variations on the near-surface conditions and the sweep signatures of surface orbital vibrators. Data processing flows of the continuous data was adapted from Vibroseis four-dimensional data processing flows. Ground roll proved a significant challenge to data processing. In addition, variations in the surface wave pattern were linked to major rainfall events. For the appraisal of surface orbital vibrators in imaging, a Vibroseis four-dimensional monitor survey data with similar geometry was also processed. Surface orbital vibrators are observed to be reliable sources with a potential to provide a repeatable signal, especially if the ground roll should fall outside the target window of interest. To guide future permanent reservoir monitoring applications, a repeatability analysis was performed for the various key data processing steps.  相似文献   

The distribution of late-Quaternary woody taxa in northern Eurasia: evidence from a new macrofossil database     

Heather A. Binney  Katherine J. Willis  Mary E. Edwards  Shonil A. Bhagwat  Patricia M. Anderson  Andrei A. Andreev  Maarten Blaauw  Freddy Damblon  Paul Haesaerts  Frank Kienast  Konstantin V. Kremenetski  Sergey K. Krivonogov  Anatoly V. Lozhkin  Glen M. MacDonald  Elena Y. Novenko  Pirita Oksanen  Tatiana V. Sapelko  Minna Väliranta  Ludmila Vazhenina 《Quaternary Science Reviews》2009,28(23-24):2445-2464

We present a database of late-Quaternary plant macrofossil records for northern Eurasia (from 23° to 180°E and 46° to 76°N) comprising 281 localities, over 2300 samples and over 13,000 individual records. Samples are individually radiocarbon dated or are assigned ages via age models fitted to sequences of calibrated radiocarbon dates within a section. Tree species characteristic of modern northern forests (e.g. Picea, Larix, tree-Betula) are recorded at least intermittently from prior to the last glacial maximum (LGM), through the LGM and Lateglacial, to the Holocene, and some records locate trees close to the limits of the Scandinavian ice sheet, supporting the hypothesis that some taxa persisted in northern refugia during the last glacial cycle. Northern trees show differing spatio-temporal patterns across Siberia: deciduous trees were widespread in the Lateglacial, with individuals occurring across much of their contemporary ranges, while evergreen conifers expanded northwards to their range limits in the Holocene.  相似文献   

Study of air-ventilated cavity under model hull on water surface     

Konstantin I. Matveev  Tyrel J. Burnett  Alex E. Ockfen 《Ocean Engineering》2009,36(12-13):930-940

The use of air cavities beneath ship hulls can lead to significant drag reduction. A study of air-ventilated cavities under a simplified hull has been undertaken. Experiments with a 56-cm-long stepped-hull model were carried in an open-surface water channel at flow velocities 28–86 cm/s. The air-cavity parameters were measured at different model positions. Different cavity forms, a strong growth of the cavity length with the flow velocity, and an optimal trim angle for the largest air-cavity area were identified. Numerical studies were conducted using a linear potential-flow method and the finite-volume viscous code Fluent. The computationally inexpensive three-dimensional potential-flow modeling predicted air-cavity shapes and provided qualitative agreement with the measured average length of the air cavity. Two-dimensional viscous modeling reasonably predicted macroscopic features and viscous effects in the air-cavity flow, while exaggerated the mixed-phase flow regions.  相似文献