bluuebunny/crossref_metadata_2025 huggingface dataset:
Pleuraempyem
Authors: Wachowiak Robin , Mayer Steffi , Lacher Martin
Published: June 2021

Das Pleuraempyem bei Kindern ist meist Folge einer Pneumonie. Aus einem anfänglich klaren Exsudat können sich ein fibropurulentes Stadium mit Fibrinpräzipitaten und Septierungen sowie im organisierten Stadium eine dicke fibröse Membran auf der Lunge entwickeln. Husten, Fieber und Dyspnoe prägen die klinische Symptomatik.

Die Therapie des Pleuraempyems ist abhängig vom Stadium und wird kontrovers diskutiert. Im Stadium I sollte das Empyem bei symptomatischen Kindern und/oder einem Erguss > 2 cm drainiert werden. In fortgeschrittenen Stadien werden über die Thoraxdrainage zusätzlich Fibrinolytika appliziert. Obwohl gegenwärtig keine Studien existieren, die eine Überlegenheit dieses Verfahrens gegenüber einer chirurgischen Therapie zeigen konnten, sind operative Strategien wie die videoassistierte thorakoskopische Chirurgie (VATS) oder die offene Dekortikation in den Hintergrund getreten. Sie kommen nur noch bei Versagen der Fibrinolysetherapie und damit selten zum Einsatz. Eine antibiotische Behandlung ist immer indiziert.
Outcomes of colonoscopy with non-anesthesiologist-administered propofol (NAAP): an equivalence trial
Authors: Alburquerque Marco , Smarrelli Antonella , Montesinos Julio Chevarria , Carreño Sergi Ortega , Fernandez Ana Zaragoza , García Alba Vargas , Frontado Cesar Ledezma , Vidal Lluís , Francesch Montserrat Figa , Lladó Ferrán González-Huix
Published: June 2021

Background and study aims Efficacy and safety of NAAP for gastrointestinal endoscopy have been widely documented, although there is no information about the outcomes of colonoscopy when the endoscopist supervises the sedation. In this context, the aim of this trial was to determine the equivalence of adenoma detection rate (ADR) in colorectal cancer (CRC) screening colonoscopies performed with non-anesthesiologist-administered propofol (NAAP) and performed with monitored anesthesia care (MAC).

Patients and methods This was a single-blind, non-randomized controlled equivalence trial that enrolled adults from a national CRC screening program (CRCSP). Patients were blindly assigned to undergo either colonoscopy with NAAP or MAC. The main outcome measure was the ADR in CRCSP colonoscopies performed with NAAP.

Results We included 315 patients per group. The median age was 59.76 ± 5.81 years; 40.5 % of patients were women. The cecal intubation rate was 97 %, 81.8 % of patients had adequate bowel preparation, withdrawal time was > 6 minutes in 98.7 %, and the median global exploration time was 24.25 ± 8.86 minutes (range, 8–70 minutes). The ADR was 62.9 % and the complication rate (CR) was 0.6 %. Analysis by intention-to-treat showed an ADR in the NAAP group of 64.13 % compared with 61.59 % in the MAC group, a difference (δADR) of 2.54 %, 95 %CI: −0.10 to 0.05. Analysis by per-protocol showed an ADR in the NAAP group of 62.98 %, compared with 61.94 % in the MAC group, δADR: 1.04 %, 95 %CI: −0.09 to 0.07. There was no difference in CR (NAAP: 0,63 vs. MAC: 0.63); P = 1.0.

Conclusions ADR in colorectal cancer screening colonoscopies performed with NAAP was equivalent to that in those performed with MAC. Similarly, there was no difference in complication rates.
Rowell Syndrome Triggered by Pregnancy
Authors: Yuce Inel Tuba , Demirci Yildirim Tuba , Erez Yesim , Can Gercek
Published: June 2021

Rowell syndrome (RS) is a rare disorder associated with lupus erythematosus
and erythema multiforme (EM)-like cutaneous lesions. This article presents a
21-year-old female patient who had been followed up for two years with a
diagnosis of systemic lupus erythematosus (SLE) and developed RS in the
second trimester of pregnancy. Our patient, whose disease exacerbated with
skin findings during pregnancy, recovered on cyclosporine treatment without
systemic involvement and delivered a healthy baby at term.
A Diastereoselective Route to Benzoannelated Bridged Sultams
Authors: Sokolov Victor V. , Klochkova Anastasiia A. , Rassadin Valentin A.
Published: June 2021

A practical diastereoselective method for the synthesis of benzoannelated tri- and tetracyclic bridged sultams has been developed. The synthetic route employs widely available, substituted o-iodoanilines and is based on intramolecular Michael addition followed by cycloalkylation with α,ω-dihaloalkanes, or vice versa. The target compounds were isolated in good yields and the diastereoselectivity of the reaction could be easily controlled by the order of Michael addition and cycloalkylation steps.
Pandemics and protectionism: evidence from the “Spanish” flu
Authors: Boberg-Fazlic Nina , Lampe Markus , Pedersen Maja Uhre , Sharp Paul
Published: June 2021

The impact of COVID-19 on recent tendencies towards international isolationism has been much speculated on but remains to be seen. We suggest that valuable evidence can be gleaned from the “Spanish” flu of 1918–20. It is well-known that the world fell into a protectionist spiral following the First World War, but scholars have almost exclusively ignored the impact of the pandemic. We employ a difference-in-differences strategy and find that the flu had a significant impact on trade policy, independent of the war. In our preferred specification, a one standard deviation increase in excess deaths during the outbreak implied 0.022 percentage points higher tariffs subsequently, corresponding to an increase of one third of a standard deviation in tariffs. Health policy should aim to avoid the experience of the interwar period and consider the international macroeconomic impact of measures (not) taken.
Understanding, engineering, and modulating the growth of neural networks: An interdisciplinary approach
Authors: Raj Vidur , Jagadish Chennupati , Gautam Vini
Published: June 2021

A deeper understanding of the brain and its function remains one of the most significant scientific challenges. It not only is required to find cures for a plethora of brain-related diseases and injuries but also opens up possibilities for achieving technological wonders, such as brain–machine interface and highly energy-efficient computing devices. Central to the brain's function is its basic functioning unit (i.e., the neuron). There has been a tremendous effort to understand the underlying mechanisms of neuronal growth on both biochemical and biophysical levels. In the past decade, this increased understanding has led to the possibility of controlling and modulating neuronal growth in vitro through external chemical and physical methods. We provide a detailed overview of the most fundamental aspects of neuronal growth and discuss how researchers are using interdisciplinary ideas to engineer neuronal networks in vitro. We first discuss the biochemical and biophysical mechanisms of neuronal growth as we stress the fact that the biochemical or biophysical processes during neuronal growth are not independent of each other but, rather, are complementary. Next, we discuss how utilizing these fundamental mechanisms can enable control over neuronal growth for advanced neuroengineering and biomedical applications. At the end of this review, we discuss some of the open questions and our perspectives on the challenges and possibilities related to controlling and engineering the growth of neuronal networks, specifically in relation to the materials, substrates, model systems, modulation techniques, data science, and artificial intelligence.
Nonlinear wave equation in a cosmological Kaluza Klein spacetime
Authors: Wang Jinhua
Published: June 2021

We prove the global existence for the Cauchy problem of a semi-linear wave equation with an arbitrary quadratic form in a cosmological Kaluza–Klein spacetime, which is the product of a Milne universe with S1. The data prescribed on t = t0 are small, and t0 > 0 can arbitrarily approach the t = 0 singularity. Our proof relies on a decomposition of the wave equation into the zero and non-zero modes, and a crucial nonlinear structure after this decomposition is observed. In addition, we introduce various modified energies and the associated energy identities according to different expectations of decaying estimates.
Cavitation generation and inhibition. I. Dominant mechanism of turbulent kinetic energy for cavitation evolution
Authors: Jin Weiwei
Published: June 2021

Through energy conservation and transformation perspectives, we numerically investigated the physical mechanism of cavitation generation surrounding the two-dimensional NACA 0015 hydrofoil using the mass-transfer cavitation model and modified-RNG k-epsilon model. Cavitation generation is triggered by strong turbulent kinetic energy (TKE) with pressure below the saturation pressure. However, cavitation development absorbs TKE as phase-change energy and decreases kinetic energy in near-wall flow fields, thereby increasing pressure according to the energy conservation law. The increased pressure closes the cavity and generates an attached vortex or re-entrant jet, which causes cavitation collapse, conversely decreasing the pressure to the saturation pressure in the leading edge. Simultaneously, the cavitation collapse releases phase-change energy that increases TKE to a maximum so that a new period begins. Cavitation evolution is an interaction between the vapor and liquid flow fields associated with energy conservation and transformation among TKE, pressure, and phase-change energy. Beyond 50% of the chord length, the TKE and pressure-energy in the near-wall flow fields decrease, resulting in the cavitation instability. Within the cavity, the relationship between the local TKE intensity and the volume fraction of water vapor is quantitatively defined as a linear function. Two designs are proposed for the verification of the mechanism and cavitation inhibition, namely, grooves on the hydrofoil surface and bilateral wings in the tail. Grooves do not affect TKE intensity significantly and hence cannot change the cavitating flows. Bilateral tail-wings transfer TKEs from the leading edge to the wake flows and inhibit the cavitation remarkably. The TKE distribution is the dominant mechanism for cavitation generation and stability.
Characterization of a new SARS-CoV-2 variant that emerged in Brazil
Authors: Imai Masaki , Halfmann Peter J. , Yamayoshi Seiya , Iwatsuki-Horimoto Kiyoko , Chiba Shiho , Watanabe Tokiko , Nakajima Noriko , Ito Mutsumi , Kuroda Makoto , Kiso Maki , Maemura Tadashi , Takahashi Kenta , Loeber Samantha , Hatta Masato , Koga Michiko , Nagai Hiroyuki , Yamamoto Shinya , Saito Makoto , Adachi Eisuke , Akasaka Osamu , Nakamura Morio , Nakachi Ichiro , Ogura Takayuki , Baba Rie , Fujita Kensuke , Ochi Junichi , Mitamura Keiko , Kato Hideaki , Nakajima Hideaki , Yagi Kazuma , Hattori Shin-ichiro , Maeda Kenji , Suzuki Tetsuya , Miyazato Yusuke , Valdez Riccardo , Gherasim Carmen , Furusawa Yuri , Okuda Moe , Ujie Michiko , Lopes Tiago J. S. , Yasuhara Atsuhiro , Ueki Hiroshi , Sakai-Tagawa Yuko , Eisfeld Amie J. , Baczenas John J. , Baker David A. , O’Connor Shelby L. , O’Connor David H. , Fukushi Shuetsu , Fujimoto Tsuguto , Kuroda Yudai , Gordon Aubree , Maeda Ken , Ohmagari Norio , Sugaya Norio , Yotsuyanagi Hiroshi , Mitsuya Hiroaki , Suzuki Tadaki , Kawaoka Yoshihiro
Published: June 2021

Significance

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants are of concern, with the P.1 variants dominating in Brazil. Brazil is now seeing a record number of deaths. Here, we report that the pathogenicity in hamsters of a P.1 variant is similar to that of nonvariant SARS-CoV-2. However, it has an expanded host range as shown by its replication in mice. Prior infection with nonvariant SARS-CoV-2 strains efficiently prevented replication of the P.1 variant in the lower respiratory tract of hamsters upon reinfection. Convalescent sera from patients infected with nonvariants or sera from messenger RNA vaccinees showed comparable neutralization titers among the P.1 and previously circulating strains. These results suggest that previous SARS-CoV-2 infection and vaccines based on the original SARS-CoV-2 will provide some protection against P.1 infection.
Assessment of the potential responses of ecosystem services to anthropogenic threats in the Eten wetland, Peru
Authors: Rojas Tania V. , Bartl Karin , Abad Jorge D.
Published: June 2021

Introduction:
Coastal wetlands are currently threatened by human drivers, such as agriculture, infrastructure development, and urban sprawl. Pressures on these ecosystems disturb their morphology and biogeochemical cycles, resulting in the degradation of ecosystem services. However, little has been done to understand the wetland response to identify proper conservation strategies. Along the Peruvian coast, wetlands present a diversity of landscapes that face similar threats and pressures; however, the ecosystem response in each one may be different.
Objective:
This study aims to assess the environmental impacts on ecosystem services based on the understanding of geomorphic features and the status of the Eten coastal wetland (Peru).
Methods:
The methodology combines the application of open-source GIS tools and the collection of field data to characterize the geomorphic settings and to analyze the changes in environmental parameters. Then, the main threats and pressures on the Eten wetland are defined and related to impacts on ecosystem services using a cause-effect model.
Results:
Overall, the results indicated that the river plays a vital role in defining the wetland landscape and functions. The biological diversity of aquatic habitats is disturbed by hydraulic structures and agricultural activities. Current land use affects supporting and regulation services, such as water regulation.
Inverse moving source problem for time-fractional evolution equations: determination of profiles
Authors: Liu Yikan , Hu Guanghui , Yamamoto Masahiro
Published: June 2021

This article is concerned with two inverse problems on determining moving source profile functions in evolution equations with a derivative order α ∈ (0, 2] in time. In the first problem, the sources are supposed to move along known straight lines, and we suitably choose partial interior observation data in finite time. Reducing the problems to the determination of initial values, we prove the unique determination of one and two moving source profiles for 0 < α ⩽ 1 and 1 < α ⩽ 2, respectively. In the second problem, the orbits of moving sources are assumed to be known, and we consider the full lateral Cauchy data. At the cost of infinite observation time, we prove the unique determination of one moving source profile by constructing test functions.
Operation of the inductively coupled array (INCA) discharge as a para-array
Authors: Lütke Stetzkamp Christian , Tsankov Tsanko Vaskov , Czarnetzki Uwe
Published: June 2021

The inductively coupled array (INCA) discharge is a plasma source with a tailored electric field configuration that allows efficient stochastic heating of the electrons. The desired field configuration is realized by an array of small planar coils. This discharge configuration offers dense plasma production at pressures as low as 0.1 Pa and option for upscaling to square meter sizes. The theoretical works, which led to the development of the INCA discharge, propose two different electric field configurations—the ortho- and the para-configuration. The initial experimental work (P. Ahr et al 2018 Plasma Sources Sci. Technol.
27 105010) studied the ortho-configuration. Here we investigate the performance of the alternative configuration, the para-array, and compare it to the ortho-configuration. The results show similar behaviour of the electrical and of the plasma parameters. However, on first sight the ortho-array appears to perform better. The differences disappear when the power actually coupled to the plasma is considered. For both configurations the electron density follows the same linear trend with the power coupled into the plasma and the electron temperature remains nearly constant as prescribed by the energy balance equation of the electrons. The power coupling efficiency for both configurations increases with the plasma density, approaching 60% at a plasma density of 1 × 1017 m−3. No signs of saturation are observed. The variation of the electron distribution functions with the pressure shows that in the para-configuration the transition into the stochastic heating mode occurs at a pressure twice lower than that for the ortho-array in a very good agreement with the theoretical expectations. Based on the comparison of the discharge parameters and its performance, the advantages and the shortcomings of using one or the other configuration are outlined.
Piezoresistive textile layer and distributed electrode structure for soft whole-body tactile skin
Authors: Lee Hyosang , Park Kyungseo , Kim Jung , Kuchenbecker Katherine J.
Published: June 2021

Tactile sensors based on electrical resistance tomography (ERT) provide pressure sensing over a large area using only a few electrodes, which is a promising property for robotic tactile skin. Most ERT-based tactile sensors employ electrodes only on the sensor’s edge to avoid undesirable artifacts caused by electrode contact. The distribution of these electrodes is critical, as electrode location largely determines the sensitive regions, but only a few studies have positioned electrodes in the sensor’s central region to improve the sensitivity. Establishing the use of internal electrodes on a stretchable textile needs further investigation into piezoresistive structure fabrication, measurement strategy, and calibration. This article presents a comprehensive study of an ERT-based tactile sensor with distributed electrodes. We describe key fabrication details of a layered textile-based piezoresistive structure, an iterative method for choosing the current injection pathways that yields pairwise optimal patterns, and a calibration process to account for the spatially varying sensitivity of such sensors. We demonstrate two sample sensors with electrodes located only on the boundary or distributed across the surface, and we evaluate their performance via three methods widely used to test tactile sensing in biological systems: single-point localization, two-point discrimination, and contact force estimation.
Magnetars and axion-like particles: probes with the hard X-ray spectrum
Authors: Fortin Jean-François , Guo Huai-Ke , Harris Steven P. , Sheridan Elijah , Sinha Kuver
Published: June 2021

Quiescent hard X-ray and soft gamma-ray emission from
neutron stars constitute a promising frontier to explore
axion-like-particles (ALPs). ALP production in the core peaks at
energies of a few keV to a few hundreds of keV; subsequently, the
ALPs escape and convert to photons in the magnetosphere. The
emissivity goes as ∼ T
6 while the conversion probability is
enhanced for large magnetic fields, making magnetars, with their
high core temperatures and strong magnetic fields, ideal targets for
probing ALPs. We compute the energy spectrum of photons resulting
from conversion of ALPs in the magnetosphere and then compare it
against hard X-ray data from NuSTAR, INTEGRAL, and XMM-Newton for a set
of eight magnetars for which such data exists. Upper limits are
placed on the product of the ALP-nucleon and ALP-photon
couplings. For the production in the core, we perform a calculation
of the ALP emissivity in degenerate nuclear matter modeled by a
relativistic mean field theory. The reduction of the emissivity due
to improvements to the one-pion exchange approximation is
incorporated, as is the suppression of the emissivity due to proton
superfluidity in the neutron star core. A range of core temperatures
is considered, corresponding to different models of the steady heat
transfer from the core to the stellar surface. For the subsequent
conversion, we solve the coupled differential equations mixing ALPs
and photons in the magnetosphere. The conversion occurs due to a
competition between the dipolar magnetic field and the photon
refractive index induced by the external magnetic
field. Semi-analytic expressions are provided alongside the full
numerical results. We also present an analysis of
the uncertainty on the axion limits we derive due to the
uncertainties in the magnetar masses, nuclear matter equation of
state, and the proton superfluid critical temperature.
Searching for dark matter particles using Compton scattering *
Authors: Wang Shang , Fu Changbo , Dai De-Chang , Wang Hongwei , Fan Gongtao , Cao Xiguang , Ma Yugang
Published: June 2021

The dark matter puzzle is one of the most important fundamental physics questions in the 21st century. There is no doubt that solving the puzzle will be a new milestone for human beings in achieving a deeper understanding of nature. Herein, we propose the use of the Shanghai laser electron gamma source (SLEGS) to search for dark matter candidate particles, including dark pseudoscalar particles, dark scalar particles, and dark photons. Our simulations indicate that, with some upgrading, electron facilities such as SLEGS could be competitive platforms in the search for light dark matter particles with a mass below tens of keV.
Pile load tests at the deepest foundation piles in Germany
Authors: Katzenbach R , Werner A , Fischer S
Published: June 2021

Since 2001 the so called Hafencity arises in Hamburg, Germany. Currently it is europes biggest urban development project. So far the most famous building of this area is the well known Elbphilharmonie. Now another impressive building is in planning – a huge skyscraper. The new skyscraper will get an over all height of 245 m. Due to the little bearing capacity of the ground a deep foundation is needed. To found the building Germanys deepest foundation piles, with length up to 75 m, will be executed. In advance, to determine the bearing capacity of the surrounding soil, four testpiles, with lengths up to more than 110 m, have been executed.
Impact of a deep foundation on enclosing wall structure of excavation
Authors: Ter-Martirosyan Z G , Vanina Yu V
Published: June 2021

The article provides a solution to the problem of the stress-strain statement of a soil mass with excavation, under the impact of a deep foundation. The solution to the problem is obtained by integrating Melan’s solution. The final expressions for the stress-strain statement components are presented. Isolines of stresses in the soil massif and reactive forces of enclosing wall structure are also given.
Non-destructive method for preliminary assessment of deformation modulus of dispersive soils
Authors: Antipov V V , Ofrikhter V G
Published: June 2021

Modern non-destructive techniques of wave analysis can be applied for the express preliminary geotechnical soil assessment. One of them is Multichannel Analysis of Surface Waves (MASW) which allows obtaining velocities profile of shear waves and the initial shear modulus for the upper section promptly and at minimal labour costs. However, the soil deformation properties assessment requires the deformation modulus that is obtained by the direct technique of plate load test (PLT). The purpose of the study is to assess the correlation between the PLT deformation modulus and the initial shear modulus determined with MASW.
Forecasting of slope stability at the object “Redevelopment of the territory “Mill of Emelyan Bashkirov and his sons”
Authors: Gandelsman I A , Gandelsman A I
Published: June 2021

The article analyzes the current state of the landslide slope of the river Oka, an assessment of landslide risks was made. Various models of ground base behavior in flat setting in the current state and taking into account prospective development are considered. A geometric model of the slope was simulated, using the software complexes “Plaxis” and “GeoStab,” factor of safety and critical sliding surfaces were determined, various anti-landslide designs for maintaining the stability of the slope were considered, technical solutions for performing landslide control were proposed.
Geotechnical properties of hemihydrate and dihydrate phosphogypsum
Authors: Saenko Y V , Shiranov A M , Nevzorov A L
Published: June 2021

The article presents the results of analyses of more than 500 samples of phosphogypsum, which is the waste in the process of phosphorous fertilizers production, consisting of calcium sulfate with admixtures of sulfuric and phosphoric acids, silica and other substances. The characteristics of hemihydrate phosphogypsum (CaSO40,5H2O), in which cementation bonds form as the hydration process proceeds, were studied on undisturbed samples taken in 1 and in 6 months, 1, 5 and 10 years after the material was dumped. It is characterized by low strength and insignificant frost-resistance, which is typical for all building materials and products based on gypsum. The cementation bonds have not been formed in dihydrate phosphogypsum (CaSO4-2H2O) and it remains a non-cohesive granular substance in the dump, so its properties were determined by the methods used in a geotechnics for sands and silty soils. The artificially prepared samples with the relative compaction of 0.80, 0.90 and 0.95 were tested. While the obtained values of the internal friction angle, cohesion and hydraulic conductivity were characteristic for fine sands, the compressibility of this material due to the solubility of the particles was substantially higher. The utilization of phosphogypsum as ground material may have limited use, provided that water protection measures are taken and the acids contained in it are neutralized.
Experimental study results of the strip foundation fragment action underpinned by a drill-injection pile with widening low end
Authors: Samokhvalov M A , Paronko A A , Matyukov A A
Published: June 2021

The article presents the results of static load tests of a strip foundation fragment (bearing plate) underpinned by a drill-injection pile, which has a widening low at its lower end. The static load tests were carried out at the experimental site in the city of Tyumen. A drill-injection pile with widening low end is an injector that has a rubber membrane-glass at its lower end. With the help of a hydraulic packer, the solution is injected into the rubber membrane-glass. After the solution has cured, a widening low end of the required volume is formed at the lower end of the injection pipe. To assess the results obtained, static load tests were also carried out both for a strip foundation fragment without underpinned using a drill-injection pile with widening low end, and a separately located drill-injection pile with widening low end. Based on the data obtained during static load tests in the course of the experimental study, graphs of dependencies were formed: the settlement of a strip foundation fragment on the pressure under its base and the settlement of the drill-injection pile with widening low end on the static load. As a result, it was found that the use of a drill-injection pile with widening low end to underpin a strip foundation fragment allows increasing the bearing capacity by an average of 30%.
Determination of the excess excavation ratio from the data of geodesic monitoring
Authors: Ter-Martirosian A Z , Isaev I O , Almakaeva A S
Published: June 2021

Introduction: During constructing tunnels by trenchless method using the shield driving method soil surface subsides. Buildings and structures which fall into the zone of influence of new construction receive additional settlements. To determine it in the calculations it is necessary to take into account the excess excavation ratio. The purpose of the study is to determine the excess excavation ratio for increasing the sample and determining the normative values of the ratio for application in design.

Materials and methods: in the article there is examines the construction of a tunnel in the city of Moscow. Calculations are carried out using the PLAXIS software package in two-dimensional and three-dimensional formulations. In the calculations the normative excess excavation ratio was included and a backward calculation was also carried out in order to determine the actual excess excavation ratio according to the data of geodesic monitoring. Results: the results showed that the excess excavation ratio varies from 0.1% to 1.2%. It is much less than the values that are included in the project according to the regulatory documentation.

Conclusions: due to the fact settlement is less than the calculation settlement, the cost of building tunnels can be reduced by reducing the cost of protective measures for buildings and structures, as well as reducing the number of buildings that can receive excess settlement.
Common mistakes made under facility construction in cramped conditions
Authors: Sokolov N S , Viktorova S S , Maguskin V V , Malyanova L I
Published: June 2021

Construction of facilities in cramped conditions requires a special approach connected with the development and implementation of measures to ensure safe operation of the surrounding buildings within the geotechnical influence. Builders often neglect the impact of a new facility construction technology on possible negative effects resulted in the existing buildings (cracks on the facades due to uneven settlement, tilts, etc.). So far the concept of a minimum price has been used when erecting a building part below the zero mark. This approach completely ignores the notion of engineering viability. At the same time builders resort to every kind of trick to reduce the cost of construction. Such an irrational method may eventually result in a substantial increase in the cost of the zero building part construction. As a rule, it can increase the construction time (agreement on a new project when replacing it with another geotechnical technology, and undergoing new expert review). This paper examines a negative case from the geotechnical practice of constructing a 16-storey residential house next to the existing five-storey one.
Development of shell structures in geotechnics and increasing their reliability and safety in modern conditions
Authors: Kasharin D D , Kasharina T P
Published: June 2021

In the interests of sustainable development of the country, improving the quality of the living environment of the population, ensuring environmental safety, it is necessary to create scientific and technological potential, which is noted in the Decree of the President of the Russian Federation and the Resolution of the Government. Based on the foregoing, this article discusses the issues of improving shell structures, composite nanomaterials, their reliability, longevity and stability in natural climatic, technogenic, social and environmental factors. A feature of the above shell structures is their ability to maintain their design shape after various influences, which is laid down in the design and technological processes. The use of shell structures made of various composite (fabric, metal-cord and rubber-fabric, etc.) materials was most widespread in the 70s and 80s of the previous century, which is characterized by the creation of various scientific schools: Sergeev B I - soft hydraulic structures; Petrakov B I -pneumatic dams, pneumatic formwork; Blinov Yu I - awning structures; Ermolov - pneumatic building structures; Stepanovich G Ya, - retaining structures for mine workings, etc. Significant successes in the creation of composite materials were made by foreign firms (Japan, Italy, USA, England, etc.).
Main reasons for strengthening foundations and base soil stabilizations of used buildings
Authors: Polishchuk A I , Semyonov I V , Demchenko V A
Published: June 2021

The paper considers main reasons of strengthening foundations and base soil stabilizations of used buildings. We analyzed more than 120 buildings with various design solutions, which were operated mainly on clay soils, identified reasons and divided them into four groups. The first group is reconstruction of buildings, including their restoration and complete overhaul. The second group is the material destruction of the foundations and a decrease in their waterproofing qualities. The third group is a violation of the stability conditions of foundations during the operation of buildings (structures). The fourth group is the development of significant deformations of buildings during their operations.
Dependence sandy soil thermal conductivity on grain-size composition
Authors: Zakharov A V , Makhover S E
Published: June 2021

The development of renewable energy sources technologies is relevant. Sun radiant energy, wind energy, water energy, earth low-potential energy are main renewable energy sources. Energy foundations are used for earth low-potential energy extraction. The research results this paper presented can be used for energy foundations calculations. It is necessary to know soil thermal characteristics to the energy foundations calculations. At the moment, there are many calculation methods for determining soil thermal characteristics, but none of them take into account their grain-size composition. The research purpose is to assess the dependence sandy soil thermal conductivity on grain-size composition. According to the research results, firstly, the influence of the density and moisture content of the soil on its thermal conductivity was confirmed, and secondly, it was established that, at the same moisture content and density, the size of the soil grains matters. Particle size distribution affects the sandy soil thermal conductivity. With an increase in the particle size, sandy soil thermal conductivity increases.
Features of clay soil deformation under triaxial block regime cyclic loading, taking into account the formation of micro and macro-cracks
Authors: Mirsayapov I T , Sharaf H M A
Published: June 2021

The main purpose of this paper is to study the parameters of strength and deformation of clay soil in conditions of triaxial compression under block regime cyclic loading. To date, there are no data on the results of studies under this loading mode. Theoretical and experimental studies of the strength and deformability of clay soil of triaxial compression 0^02=03 under block regime cyclic loads are carried out. A distinctive feature of the experimental studies is that they were carried out in devices of triaxial compression of a prismatic shape with an aspect ratio of 100x 100x200mm. In the study of vibration creep deformations and changes in the fatigue resistance to the destruction of clay soils under triaxial regime block cyclic loading. It is established that the stress-strain state, deformation, and fatigue strength of soil vary depending on the sequence of alternating blocks with different values of the maximum load of the cycle. The developed and obtained equations describing the deformation of the soil under these conditions with the development of micro-cracks observed in experiments of hardening and softening effect of inhibition at different stages of cyclic triaxial compression allow to accurately estimate vertical deformation (settlement) bases under regime loading and to obtain reliable and economical design solutions.
Method for calculating the settlement of ring pile foundations of tanks
Authors: Polishchuk A I , Shmidt O A
Published: June 2021

Annotation. A method for calculating the settlement of ring pile foundations of reservoirs on clay soils is considered. The proposed method provides for a separate calculation of the settlement of the central part of the tank (bottom draft) and a reinforced concrete ring pile foundation arranged along its edges (foundation ring settlement). The bottom of the tank is not rigidly connected to the ring foundation. The method of M I Gorbunov-Posadov and others for a flexible round foundation on a linearly deformable base was used. When calculating the settlement of the pile ring, the method of A A Bartolomey was used for strip pile foundations. The work takes into account the assessment of the additional settlement of the bottom and pile ring caused by repeated loading and unloading of the base of the tanks.
The choice of a metal sheet piling for the construction of the foundation pit
Authors: Nazarova E V , Kaloshina S V , Zolotozubov D G
Published: June 2021

Sheet piles are often used for fencing deep excavations. This is due, among other things, to the fact that when they are pressed, there is no negative impact on the surrounding buildings. In the course of the study, a technical and economic comparison of the domestic sheet pile L4 and its foreign analogue VL603K was carried out. The relevance of the study is confirmed by the fact that during the construction of underground parts of buildings and structures, great attention is paid to engineering measures to prevent the ingress of groundwater into the pits, as well as to strengthen the walls of the excavations from the possibility of collapse in unstable and water-bearing soils. It is also taken into account that the choice of the foundation pit construction depends on its depth, the level of groundwater and the structural scheme of the underground part of the structure, it is also necessary to carry out a static calculation to determine the thickness of the fence and its immersion depth. The analysis of sheet piles also revealed their disadvantages and advantages.
Advantages of using BIM (BIM-technology) for the design and construction of subsoil use industry buildings and structures
Authors: Shenkman R , Ponomaryov A
Published: June 2021

The article provides information about the advantages of using information modeling technologies in the design and construction of facilities for subsoil use enterprises. The data on the state of the art of studying the aspects of the application of information modeling technologies in the field of industrial construction are presented. Recommendations for planning methods and the development of information models of buildings and structures of subsoil use objects are presented on base of the study of existing research. The article also provides information on the test information models of subsoil use industrial facilities which are necessary for the development of recommendations for the choice of levels of the attribute information of elements, for the correct and effective use of models at all stages of the object’s life cycle.
Numerical analysis and practical application of methods for strengthening foundations with piles during reconstruction process
Authors: Polischuk A I , Petukhov A A
Published: June 2021

The article describes the reconstruction of the historical stone building basements. It provides a brief description of the constructive solution of the buildings under consideration and summarizes information about their technical condition. The article highlights the importance of analyzing information about the construction and operation of buildings during the entire history. This article lists the main tasks of the reconstruction of historical buildings: area augmentation due to the reconstruction of previously unexploited basements, deepening of basements, expansion of existing openings in the walls and construction of new ones, arrangement of new entrance nodes into the basements of a building, etc. Besides, the article gives a brief description of the soil conditions of the reconstructed buildings sites, which are typical for historical buildings in Tomsk. It points out the need for thorough engineering and geological examinations with additional geotechnical examination of the soil base. Additionally, the paper clarifies the necessity to examine the characteristics of supporting layer foundation soils, changed due to their compaction by the weight of the building during the period of long-term operation. The results obtained during the examination and assessment of the technical condition of foundations and overhead building structures will be presented. Also, this study proposes classification of methods for strengthening natural foundations (freestanding, strip, slab and massive) using piles. In particular, it talks about piles that are installed without soil extraction - displacement piles (pressed and injected), as well as examples of numerical modeling of the work of detached and strip foundations reinforced with the use of piles when the basement floor elevations are lowered. Finally, it shows he experience of scientific and technical support for the reconstruction of buildings.
Electron-deficient N-oxyl radicals – new reagents for selective oxidative functionalization of organic substrates
Authors: Krylov I B , Budnikov A S , Lopat’eva E R , Segida O O , Paveliev S A , Terent’ev A O
Published: June 2021

N-oxyl radicals are well known as one of the richest classes of long-living free radicals. They are widely used as redox catalysts, mediators of living polymerization, contrast reagents for tomography applications, spin labels for biomacromolecule studies, components of organic batteries and magnetic materials. In the last decade, less stable but more reactive electron-deficient N-oxyl radicals have been harnessed as reagents for oxidative functionalization of organic substrates via selective C-H bond cleavage or radical addition to C = C bonds. Wide array of C-O coupling products can be achieved employing N-oxyl radicals as O-reagents for oxidative C-O coupling. Selected examples of methods for oxidative functionalization of organic substrates by N-oxyl radicals developed in our group are summarized in the present paper.
Semi-empirical evaluation of linear coefficient of thermal expansion of metals
Authors: Palii N A , Belousov O K
Published: June 2021

The paper considers various semi-empirical methods of the linear coefficient of thermal expansion (CTE), a, calculation. Debye-Grüneisen model was used as a basis and adjusted by taking account of thermodynamic (molar heat capacity, enthalpy) and elastic (Young, bulk, and shear moduli, Poison ratio) characteristics of metals. The formulas for numerical calculations of CTE are derived using: (1) elastic longitudinal modulus, (2) microscopic constants, and (3) enthalpy. CTE were calculated for 25 metals, Ge and Si, and five hexagonal single-crystals in directions perpendicular and parallel to the principle crystallographic axis. Theoretical values of a show good agreement with the experimental ones.
Apparatus and technological design of the production process of activated highly porous carbon material
Authors: Popova A A , Shubin I N
Published: June 2021

The possibility of developing activated highly porous carbon materials with a maximum specific surface area is shown. Their classification, the main stages of research and the results obtained are considered. A schematic diagram of the production of a material with a BET specific surface in the range of 2400-3600 m2 / g is presented. The main stages in the production of an activated highly porous carbon material have been determined, including the preliminary carbonization of carbon raw materials, its alkaline activation and post-processing of the resulting material (from the pre-preparation of the components and the preparation of the reaction mixture to the subsequent isolation and drying of the finished product). The composition of the equipment and the possibility of a large-scale transition of the instrumental and technological design of the production process from laboratory to pilot industrial have been established. The obtained activated highly porous carbon material can be used as sorbents in gas media purification systems and in gas accumulators, as well as for solving various environmental problems.
Research of the efficiency of scientific and technical results in the field of chemical safety based on big data analysis
Authors: Pronichkin S V , Mamai I B
Published: June 2021

The search and extraction of targeted information about promising and breakthrough technologies for ensuring chemical safety is an important element in the analysis of large volumes of unstructured scientific and technical data. Existing approaches to processing large amounts of unstructured data can lead to distortion of the original information. New approaches to the search and extraction of target information based on the typification of the display of visualized large volumes of data of scientific and technical programs are proposed. It is proposed to overcome the disadvantages of existing approaches by using the representation of multi-attribute objects based on the multiset formalism, which allows one to simultaneously take into account all combinations of attribute values, as well as a different number of values for each of them. Multi-feature objects presented as multisets are proposed to be divided into relevant and irrelevant in terms of similarity to the reference multiset based on various metrics. This approach makes it possible to level the features of the initial data and opens up opportunities for solving new problems of studying large volumes of unstructured information of various nature. The results of the computational experiments in the chemical engineering field have shown the effectiveness of the proposed methodological approaches to the search and extraction of target information from large volumes of unstructured data of scientific and technical programs.
Effect of the grain composition of the initial silicon carbide powder on the structure and properties of reaction-sintered silicon carbide
Authors: Tomkovich M V
Published: June 2021

The paper shows the effect of different dispersed compositions of initial silicon carbide powders on the microstructure, strength, and crack resistance of reaction-sintered silicon carbide.
Dynamics of the number of aphids-vectors of viruses in the vertical zoning of the North Caucasus
Authors: Gazdanova I O , Gerieva F T
Published: June 2021

Viral diseases are recognized as the most dangerous potato diseases due to the fact that their development can bring significant economic losses. Viruses infecting potatoes carry a significant number of vectors. Aphids are carriers of viral diseases. The results of studying aphidofauna showed that the most important carriers of potato viruses in the North Caucasus are aphids-peach, leguminous, large potato, common potato.
The plasma atomization process for the Ti-Al-V powder production
Authors: Kalayda T A , Kirsankin A A , Ivannikov A Yu , Konushkin S V , Kaplan M A , Sevostyanov M A
Published: June 2021

The paper presents brief information on the characteristics of the spherical powder of the Ti-Al-V alloy, produced by the method of plasma atomization of the wire. The scheme of the equipment and the results of studying the powder of the Ti-Al-V alloy are shown.
Introduction of in Vitro Grapes of Interspecific Origin
Authors: Akimova S V , Kirkach V V , Radjabov A K , Panova M B , Voskoboinikov Yu V , Ermorlina M A , Ter-Petrosyants G E
Published: June 2021

During clonal micro-propagation of grapes of interspecific origin of the Aleshenkin variety, it was revealed that the optimal type of explants for initiating a sterile culture are meristematic apexes 100 – 150 μm in height, which are advisable to be planted in test tubes on a nutrient medium according to the prescription of Quorin Lepuavr (QL) (Quoirin & Lepoivre, 1977) enriched with the following substances (mg/l): thiamine (B1), pyridoxine (B6), nicotinic acid (PP) – 0.5 each; 6-BAP – 0.1; inositol – 100; sucrose – 30,000, agar-agar – 7,000 and incubate for 70 days in a light room at an illumination intensity of 2,500 lux, a 16-hour photoperiod and a temperature of 20 – 22 C. At the multiplication stage, with two consecutive passages of 40 days of sub-culturing on a nutrient medium according to the prescription of Murashige and Skoog (MS) (Murashige & Skoog, 1962), enriched with the following substances (mg/l): thiamine (B1), pyridoxine (B6), nicotinic acid (PP) – 0.5 each; 6-BAP – 0.1, inositol – 100; sucrose – 30,000, agar-agar – 7,000, the advantage of this type of explants has been shown. Since in terms of the coefficient of multiplication, regenerant plants introduced into culture in vitro by meristematic apexes after the first passage were 2.3 times and after the second passage 1.4 times higher than the plants introduced into culture by micro-cuttings.