Magnetic Flux Leakage Method: Large-Scale Approximation

We consider the application of the magnetic flux leakage (MFL) method to the detection of defects in ferromagnetic (steel) tubulars. The problem setup corresponds to the cases where the distance from the casing and the point where the magnetic field is measured is small compared to the curvature radius of the undamaged casing and the scale of inhomogeneity of the magnetic field in the defect-free case. Mathematically this corresponds to the planar ferromagnetic layer in a uniform magnetic field oriented along this layer. Defects in the layer surface result in a strong deformation of the magnetic field, which provides opportunities for the reconstruction of the surface profile from measurements of the magnetic field. We deal with large-scale defects whose depth is small compared to their longitudinal sizes---these being typical of corrosive damage. Within the framework of large-scale approximation, analytical relations between the casing thickness profile and the measured magnetic field can be derived.Comment: 12 pages, 3 figure

Ancient steroids establish the Ediacaran fossil Dickinsonia as one of the earliest animals

The enigmatic Ediacara biota (571 million to 541 million years ago) represents the first macroscopic complex organisms in the geological record and may hold the key to our understanding of the origin of animals. Ediacaran macrofossils are as “strange as life on another planet” and have evaded taxonomic classification, with interpretations ranging from marine animals or giant single-celled protists to terrestrial lichens. Here, we show that lipid biomarkers extracted from organically preserved Ediacaran macrofossils unambiguously clarify their phylogeny. Dickinsonia and its relatives solely produced cholesteroids, a hallmark of animals. Our results make these iconic members of the Ediacara biota the oldest confirmed macroscopic animals in the rock record, indicating that the appearance of the Ediacara biota was indeed a prelude to the Cambrian explosion of animal life.The study is funded by Australian Research Council grants DP160100607 and DP170100556 (to J.J.B.), Russian Foundation for Basic Research project 17-05-02212A (A.I. and I.B.), and the Max-Planck-Society (C.H.). I.B. gratefully acknowledges an Australian Government Research Training Program stipend scholarship, and B.J.N. acknowledges a Geobiology fellowship of the Agouron Institute

Rapid selection of BRCA1-proficient tumor cells during neoadjuvant therapy for ovarian cancer in BRCA1 mutation carriers

Ovarian carcinomas (OC) often demonstrate rapid tumor shrinkage upon neoadjuvant chemotherapy (NACT). However, complete pathologic responses are very rare and the mechanisms underlying the emergence of residual tumor disease remain elusive. We hypothesized that the change of somatic BRCA1 status may contribute to this process. The loss-of-heterozygosity (LOH) at the BRCA1 locus was determined for 23 paired tumor samples obtained from BRCA1 germ-line mutation carriers before and after NACT. We observed a somatic loss of the wild-type BRCAI allele in 74% (17/23) of OCs before NACT. However, a retention of the wild-type BRCA1 copy resulting in a reversion of LOH status was detected in 65% (11/17) of those patients after NACT. Furthermore, we tested 3 of these reversion samples for LOH at intragenic BRCA1single nucleotide polymorphisms (SNPs) and confirmed a complete restoration of the SNP heterozygosity in all instances. The neoadjuvant chemotherapy for BRCA1-associated OC is accompanied by a rapid expansion of pre-existing BRCA1-proficient tumor clones suggesting that continuation of the same therapy after NACT and surgery may not be justified even in patients initially experiencing a rapid tumor regression. (C) 2017 Elsevier B.V. All rights reserved.Peer reviewe

Control of fingering instability by vibrations

In applications involving the injection of a fluid in a porous medium to displace another fluid, a main objective is the maximization of the displacement efficiency. Displacement fronts moving in porous media are subjected to hydrodynamic instability when a liquid of low viscosity displaces a high-viscosity liquid and consequently finger-like structure forms along the interface. This finger instability is usually undesirable in technical applications and natural filtration processes. We discuss the external periodic forcing as one of the promising ways to control the instability and perform numerical simulation of an initially spherical drop in a porous media under vertical vibrations. The drop is a favorable object to study since in this case one can observe the effect of vibrations on fluid interface domains inclined by different angles with respect to vibration axis. It is shown that under vibrations small-scale perturbations of interface are suppressed and in the case of vibrations of large enough intensity the drop becomes stable. The stability criterion is derived

Numerical studies of the combustion of fuel oil in the boiler furnace at reduced load

Relevance of the work due to the need to assess the effectiveness and reliability of the boiler units on reserve fuel after reconstruction associated with a change in the base fuel and approaches of numerical analysis. Analysis of physical and chemical processes in the furnace volume of boiler BKZ–210–140 operating on reserve fuel and rated load when using the Euler and Euler combined and Lagrangian modeling approaches. Results of the numerical modeling of the processes of aerodynamics, heat exchange, and combustion in the furnace volume

Numerical studies of the combustion of fuel oil in the boiler furnace at reduced load

Relevance of the work due to the need to assess the effectiveness and reliability of the boiler units on reserve fuel after reconstruction associated with a change in the base fuel and approaches of numerical analysis. Analysis of physical and chemical processes in the furnace volume of boiler BKZ–210–140 operating on reserve fuel and rated load when using the Euler and Euler combined and Lagrangian modeling approaches. Results of the numerical modeling of the processes of aerodynamics, heat exchange, and combustion in the furnace volume

The data for figures in the paper "Phase-field modelling of gravity-capillary waves on a miscible interface"

The data is for figures in the paper &quot;Phase-field modelling of gravity-capillary waves on a miscible interface&quot; to be published in European Physical Journal E.</span

Phase-field modelling of gravity-capillary waves on a miscible interface

Using the approach of direct numerical simulations we investigate the gravity-capillary waves induced on a horizontal interface between two slowly miscible liquids. It is assumed that the liquids are just brought into contact, and thus the interface is slowly smeared by the action of interfacial diffusion. It is also assumed that the initial shape of the interface is distorted by harmonic perturbations, which results in development of the gravity-capillary surface waves. The evolution of the binary mixture is modelled on the basis of the phase-field method. Our results show that in the limiting case of negligible diffusion the classical dispersion relations for immiscible interfaces can be reproduced. Although, for the waves with shorter wavelengths such an agreement is more difficult to obtain. The interfacial diffusion brings an additional dissipation to the fluid system, strongly damping the development of the shorter waves. We also show that the mixing (or the transition of a binary system to the state of thermodynamic equilibrium) is intensified by the presence of the surface waves, and this effect is more important when the liquids are slowly miscible, i.e. when the interfacial diffusion is weak

Figure 2 in Oldest shrimp and associated phyllocarid from the Lower Devonian of northern Russia

Figure 2. Archangeliphausia spinosa sp. nov. A, holotype (PIN 4983/1a: right) and associated specimen (PIN 4983/1b). B, largest specimen found (PIN 4983/35), with relatively thick cuticle. C, juvenile specimen (PIN 4983/37). E, specimen with dorsoventrally compressed telson and uropods (PIN 4983/28; see also Fig. 4C). D, posterior part of abdomen with well preserved 6th pleosomite and telson (PIN 4983/8).Published as part of &lt;i&gt;Dzik, Jerzy, Ivantsov, Andrey Yu. &amp; Deulin, Yuriy V., 2004, Oldest shrimp and associated phyllocarid from the Lower Devonian of northern Russia, pp. 83-90 in Zoological Journal of the Linnean Society 142 (1)&lt;/i&gt; on page 87, DOI: 10.1111/j.1096-3642.2004.00121.x, &lt;a href="http://zenodo.org/record/10114602"&gt;http://zenodo.org/record/10114602&lt;/a&gt

Instability of an average flow in an annulus at rotational vibration

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