bluuebunny/crossref_metadata_2025 huggingface dataset:
Empirical treatment of asymptomatic contacts of gonorrhoea: patient views
Authors: McIver Ruthy , Low Sheina , Varma Rick , Vickers Tobias , McNulty Anna
Published: November 2020

Background
The prevalence of Neisseria gonorrhoeae (gonorrhoea) in sexual contacts of gonorrhoea has not been established, but limited data suggest that the majority of contacts are not infected. Contacts of gonorrhoea who receive empirical treatment at the point of testing may receive unnecessary antimicrobial treatment for an infection that is known to have multidrug resistance. This study evaluated patient acceptability of non-empirical treatment.? Methods: We conducted an anonymous cross-sectional survey of patients attending sexual health centres in New South Wales, Australia, on the acceptability of empirical and non-empirical treatment models and patients’ concerns about antimicrobial resistance. Results: Most of the 823 survey participants were willing to wait for treatment until their results were reported; 77% and 53% would agree to wait for treatment if results were available in 2 and 7 days respectively. Participants were less likely to agree to non-empirical treatment if they lived in regional and remote areas compared with those in a major city (odds ratio (OR) 0.5; 95% confidence interval (CI) 0.35–0.73). Most participants (70%) were worried about infections becoming resistant to antibiotics, with heterosexual men and women being less likely than gay and bisexual men to be worried (heterosexual men: OR 0.64, 95% CI 0.44–0.94; women: OR 0.64 95%, CI 0.44–0.92). Conclusions: Non-empirical treatment was acceptable to most participants, but patient preference, ability to return for treatment and timeliness of results are factors that should inform individual treatment decisions.
Designed nanomolar small-molecule inhibitors of Ena/VASP EVH1 interaction impair invasion and extravasation of breast cancer cells
Authors: Barone Matthias , Müller Matthias , Chiha Slim , Ren Jiang , Albat Dominik , Soicke Arne , Dohmen Stephan , Klein Marco , Bruns Judith , van Dinther Maarten , Opitz Robert , Lindemann Peter , Beerbaum Monika , Motzny Kathrin , Roske Yvette , Schmieder Peter , Volkmer Rudolf , Nazaré Marc , Heinemann Udo , Oschkinat Hartmut , ten Dijke Peter , Schmalz Hans-Günther , Kühne Ronald
Published: November 2020

Significance

Protein–protein interactions mediated by proline-rich motifs are involved in regulation of many important signaling cascades. These motifs belong to the most abundant recognition motifs in the eukaryotic genome and preferentially adopt a left-handed polyproline helix II, a secondary structure element that has been notoriously difficult to mimic with small molecules. Here, we present a structure-guided design effort yielding a toolkit of chemical entities that enables rational construction of selective small molecule inhibitors for these protein domains. We succeeded in developing an inhibitor for the Ena/VASP protein family that is active in vivo and reduces extravasation of invasive breast cancer cells in a zebrafish model.
Markov state modeling reveals alternative unbinding pathways for peptide–MHC complexes
Authors: Abella Jayvee R. , Antunes Dinler , Jackson Kyle , Lizée Gregory , Clementi Cecilia , Kavraki Lydia E.
Published: November 2020

Significance

Peptide binding to MHC receptors is part of a central biological process that enables our immune system to attack diseased cells. We use molecular simulations to illuminate the mechanisms driving stable peptide–MHC binding. Our simulation framework produces an atomistic model of the unbinding dynamics for a given peptide–MHC, which quantifies transitions between the major states of the system (bound, intermediate, and unbound). We applied this framework to study the binding of a SARS-CoV peptide to the HLA-A*24:02 receptor. This work revealed the unexpected importance of peptide’s position 4 in driving the stability of the complex, a finding with broader biomedical implications. Our methods can be applied to other peptide–MHC complexes, requiring only a 3D model as input.
The SKI complex is a broad-spectrum, host-directed antiviral drug target for coronaviruses, influenza, and filoviruses
Authors: Weston Stuart , Baracco Lauren , Keller Chloe , Matthews Krystal , McGrath Marisa E. , Logue James , Liang Janie , Dyall Julie , Holbrook Michael R. , Hensley Lisa E. , Jahrling Peter B. , Yu Wenbo , MacKerell Alexander D. , Frieman Matthew B.
Published: November 2020

Significance

The SARS-CoV-2 pandemic of 2020 has highlighted the great need for antiviral therapeutics. In this work, we identify a host factor, the SKI complex, is involved in replication of influenza and coronaviruses. Using computational modeling we were able to identify chemicals that interact with the host factor that display broad-spectrum antiviral activity against influenza, coronaviruses, and filoviruses, all of which cause significant morbidity and mortality. Broad-spectrum antiviral therapeutics are sorely needed to combat known and unknown viral pathogens and the work presented here is our first step to developing antivirals to target the SKI complex.
How to mix
Authors: Torres Cacoullos Rena , Dion Nathalie , LaCasse Dora , Poplack Shana
Published: November 2020

The widespread occurrence of nouns in one language with a determiner in the other, often referred to as mixed NPs, has generated much theorizing and debate. Since both a syntactic account based on abstract features of the determiner and an account highlighting the notion of a Matrix language yield largely the same predictions, we assess how the tenets of each play out in speaker choices. The data derive from a massive corpus of spontaneous nominal mixes, produced by bilinguals in New Mexico, where bidirectional code-switching is the norm. Bilinguals’ choices concern (1) NP status (mixed vs. unmixed); (2) mixing type (limited-item vs. multi-word); and (3) language of the noun (here, English vs. Spanish). Results show that the community preference is for mixed NPs, independent of their theoretical felicity as dictated by determiner language properties. As to mixing type, these NPs are mostly constituted of lone nouns, such that the language of the determiner and any associated verb is perforce that of the surrounding discourse. Finally, the overwhelming choice is for English lone nouns incorporated into Spanish, and hence for a Spanish determiner. The language of the determiner thus proceeds, not from abstract linguistic properties, but instead from straightforward adherence to bilingual speech community conventions.
Light-headed relative clauses in Teramano
Authors: Mantenuto Iara , Caponigro Ivano
Published: November 2020

We investigate an unstudied, rich component of the relative clause system in Teramano, one of the Upper Southern Italian
languages. We focus on light-headed relative clauses – relative clauses that lack a full nominal head and are introduced by only a
Determiner-like or pronominal “light head”. We also briefly describe headed relative clauses in Teramano since the morphosyntactic features
they exhibit are relevant for the investigation of light-headed relative clauses. Last, we highlight commonalities and differences between
light-headed relative clauses in Teramano and Italian. Our paper provides the first systematic in-depth description of light-headed relative
clauses in an Upper Southern Italian language that we are aware of, contributes to the knowledge of Teramano, the study of light-headed
relative clauses crosslinguistically, and the ongoing investigation of microvariation among Italian and Italian languages.
Defining with Simple Vocabulary in English Dictionaries
Authors: Kamiński Mariusz Piotr
Published: November 2020

This book investigates an important but under-researched aspect of dictionary making: the use of a controlled vocabulary in definitions. The main concern of the author is the role of a definition vocabulary in how foreign learners understand and perceive dictionary definitions. The author takes the reader through a detailed historical account of controlled vocabularies and examines definitions in a range of English dictionaries with respect to their vocabulary loads. He performs a series of experiments with university students to reveal merits and shortcomings of restricted vocabularies. This monograph has been written with the aim to fill a gap in the literature on defining vocabulary. It is intended for lexicographers, dictionary editors, course designers, teachers, and students, as well as anyone who wishes to explain words in an intelligible way.
Effect of carbon on the microstructure and element distribution in Ti42Al5Mn alloy
Authors: Tang Hongjian , Li Xiaobing , Xing Weiwei , Ma Yingche , Chen Bo , Liu Kui , Xia Yuanhua , Lin Kun
Published: November 2020

The role of C on microstructure and local chemical composition of an as-cast Ti42Al5Mn alloy was systematically characterised. Results show that C is enriched in α2, less dissolved in γ but depleted in βo phase. Crossing the C-solubility limit, approximately 0.3 at. %, leads to the precipitation of h-type carbides (Ti2AlC). Furthermore, a correlation between the lattice site preference and the C-solubility is rationalised by neutron powder diffraction technique, suggesting that Mn tends to substitute the position of Al site within the γ-phase (L10-lattice) with an occupancy rate of 4.31%. Consequently, fewer Ti6-type sites are formed where C is preferentially located. Finally, the interlamellar spacing and phase evolution as well as the preferential distribution of alloying elements are also evaluated.
Temporal evolution of electron energy distribution function and its correlation with hydrogen radical generation in atmospheric-pressure methane needle–plane discharge plasmas
Authors: Liu Yadi , Zhang Shuai , Huang Bangdou , Dai Dong , Murphy Anthony B , Shao Tao
Published: November 2020

Non-thermal plasmas show great potential in low-temperature activation of methane (CH4) owing to the abundant energetic active species. Motivated by the fact that the chemical reactions in plasma-based CH4 conversion are dominated and regulated by the energetic electrons and various radicals, the temporal evolution of the electron energy distribution function (EEDF) and its relation to hydrogen (H) radical generation in an atmospheric-pressure CH4 needle–plane discharge plasma have been investigated numerically. The simulations are carried out using one-dimensional particle-in-cell Monte-Carlo collision and fluid dynamic models. It can be shown that during the formation and development of the streamer, a characteristic time exists, before and after which the evolution characteristic of the EEDF is reversed. This is mainly attributed to the competition between the energies continuously obtained from the electric field and the increasingly strong inelastic collisions and fast-growing low-energy electron population. When the amplitude of the applied voltage is increased, the fraction of electrons with high enough energy to participate in dissociation or ionization reactions of CH4 increases, leading to an increased H density. Besides, the characteristic time decreases exponentially, and the energy efficiency of the activation of CH4 molecules is decreased. An appropriate electron energy distribution and H radical density should be chosen to ensure acceptable product selectivity and conversion rate without excessive energy consumption; this will depend on the required products. The results presented in this work provide a partial theoretical basis for effectively optimizing the content of high-energy electrons and H radicals.
Modelling of long-term retention of high-fired plutonium oxide in the human respiratory tract: importance of scar-tissue compartments
Authors: Poudel Deepesh , Avtandilashvili Maia , Klumpp John A , Bertelli Luiz , Tolmachev Sergei Y
Published: November 2020

The U.S. Transuranium and Uranium Registries whole-body tissue donor Case 0407 had an acute intake of ‘high-fired’ plutonium oxide resulting from a glove-box fire in a fabrication plant at a nuclear defence facility. The respiratory tract of this individual was dissected into five regions (larynx, bronchi, bronchioles, alveolar-interstitial, and thoracic lymph nodes) and analysed for plutonium content. The activities in certain compartments of the respiratory tract were found to be higher than expected from the default models described in publications of the International Commission on Radiological Protection. Because of the extremely slow rate of dissolution of the material inhaled, the presence of bound fraction is incapable of explaining the higher-than-expected retention. A plausible hypothesis—encapsulation of plutonium in scar tissues—is supported by the review of literature. Therefore, scar-tissue compartments corresponding to the larynx, bronchi, bronchioles and alveolar-interstitial regions were added to the existing human respiratory tract model structure. The transfer rates between these compartments were determined using Markov Chain Monte Carlo analysis of data on urinary excretion, lung counts and post-mortem measurements of the liver, skeleton and regional retention in the respiratory tract. Modelling of the data showed that approximately 30% of plutonium activity in the lung was sequestered in scar tissues. The dose consequence of such sequestration is qualitatively compared against that of chemical binding.
Investigating the UV absorption capabilities in novel Ag@RGO/ZnO ternary nanocomposite for optoelectronic devices
Authors: Hashem Elhussein M , Hamza Mahmoud A , El-Shazly Ayat N , Sanad Mohamed F , Hassan Minatallah M , Abdellatif Sameh O
Published: November 2020

A facile one-pot method was utilized at room-temperature for the synthesis of novel ternary nanocomposite of Ag@RGO/ZnO, which is introduced as a low cost, efficient and reliable UV absorber. The crystalline, morphological, structural, and optical characteristics of the as-synthesized samples were investigated by various techniques such as XRD, FE-SEM, HR-TEM, XPS, and DRS. The measurements confirm the successful fabrication of the Ag@RGO/ZnO ternary nanocomposite. Optical characterization showed the synergetic role of Ag NPs and RGO NSs in the enhancement of the light absorption of the ternary nanocomposite in the UV portion compared to the bare ZnO NPs. Additionally, band-gap narrowing was observed due to the Ag-doping impact where potential applications for the proposed nanocomposite have been suggested.
Three-dimensional simulation of neutral transport in gases and weakly ionized plasmas
Authors: Varshavchik L A , Babinov N A , Zatylkin P A , Chironova A A , Lyullin Z G , Chernakov Al P , Dmitriev A M , Bukreev I M , Mukhin E E , Razdobarin A G , Samsonov D S , Senitchenkov V A , Tolstyakov S Yu , Serenkov I T , Sakharov V I
Published: November 2020

Transport and redeposition of plasma-facing materials in future fusion devices may have a critical influence on performance of in-vessel components. Evaluation of the impurity migration in diagnostic ports is important to predict degradation of in-vessel optics during the main plasma discharges as well as for development of in-situ cleaning maintenance. The Monte-Carlo code KITe was developed for modeling transport of neutral particles in weakly ionized plasma. The code employs advanced neutral particle collision model. The first KITe simulation and experimental validation of sputtered atom transport demonstrate performance of the proposed approach.
HVPE growth of bulk GaN with high conductivity for vertical devices
Authors: Xia Songyuan , Zhang Yumin , Wang Jianfeng , Chen Jihu , Xu Ke
Published: November 2020

The electrical properties of gallium nitride (GaN) substrate are crucial to the performance of vertical power devices. Bulk GaN substrates with carrier concentrations in the range from 6.7 × 1017 to 1.7 × 1019 cm−3 are grown by hydride vapor phase epitaxy. All samples show no obvious tensile stress regardless of the carrier concentration. Moreover, the mobility of Si-doped high-quality bulk GaN is superior to the GaN template with higher dislocation density at the same carrier concentration. The influence of carrier concentration on the performance of ohmic contact on N-face of Si-doped GaN is also carefully studied by circular transfer length measurement and rapid thermal annealing methods. The specific contact resistivity decreases monotonically with increase of carrier concentration, while it increases with the annealing temperature. The N-face contact becomes non-ohmic when the annealing temperature exceeds the limit value, which increases with the carrier concentration. The sample with carrier concentration of 1.7 × 1019 cm−3 still showed ohmic behavior after annealing at 450 °C. These results are not only useful to improve the electrical properties of N-type bulk GaN substrate, but also provide a potential solution for improving the efficiency of vertical devices in the future.
High-speed interrogation of multiplexed fiber Bragg grating sensors for monitoring dynamic strain responses during a flexible plate impact on a water surface
Authors: Wong Kit Pan , Kim Hyun-Tae , Wang An , Kiger Kenneth , Duncan James H , Yu Miao
Published: November 2020

The investigation of fluid-structure interaction during the impact of a flexible plate on a water surface has received much attention. Measurement of highly transient, distributed strain of the plate during the slamming event is of great interest. Multiplexed fiber Bragg grating (FBG) strain sensors provide a promising solution for such measurement since these sensors are inherently waterproof and are immune to electromagnetic interference. However, in order to monitor the highly transient, distributed strain responses (up to 20 kHz), high-speed simultaneous interrogation of multiplexed FBG sensors is required, which is challenging by using commercial optical interrogators. We present a tunable-wavelength-filter-based optical interrogation system for high-speed simultaneous interrogation of multiplexed FBG strain sensors and demonstrate its application for structural monitoring of a flexible plate during the slamming event. The interrogation system employs a piezoelectric-transducer-controlled Fabry–Perot tunable filter. By operating the tunable filter at its resonant frequency and demodulating the sensor signal based on a peak tracing method, we demonstrated an interrogation speed of 100 kHz, an interrogation range of 98 nm, and an interrogation resolution of 5 pm. For proof-of-performance, the interrogation system was used to monitor the vibrational responses of a cantilever plate under impact loading and the measurement of vibration modes up to 6.785 kHz was demonstrated. Finally, the slamming experiments were carried out with six multiplexed FBG strain sensors mounted on a flexible plate. The dynamic strain measurement of the plate during the slamming event was successfully demonstrated by using the high-speed FBG interrogation system.
Universal function of the diffractive process in color dipole picture
Authors: Jalilian Z. , Boroun G. R.
Published: November 2020

In this study, we obtain the universal function corresponding to the diffractive process and show that the cross section exhibits geometrical scaling. It is observed that diffractive theory according to the color dipole approach at small-x is a convenient framework that reveals the color transparency and saturation phenomena. We also calculate the contribution of heavy quark production in the diffractive cross section at high energy that is determined by the small size dipole configuration. The ratio of the diffractive cross section to the total cross section in electron-proton collision is the other important quantity that is computed in this work.
CXRS measurements of energetic helium ions in ASDEX Upgrade plasmas heated with a 3-ion ICRF scenario
Authors: Kappatou A. , Weiland M. , Bilato R. , Kazakov Ye.O. , Dux R. , Bobkov V. , Pütterich T. , McDermott R.M.
Published: November 2020

Fast ion physics is an active field of research in the fusion community, but most studies focus on deuterium fast ions. The generation and investigation of energetic helium in present devices, however, provide significantly more insight on how the fast alpha particles produced from fusion reactions, will behave in future reactor plasmas. Fast helium ion populations can be measured with charge exchange recombination spectroscopy (CXRS) in the wings of the helium spectral line (He II
n = 4–3, 468.6 nm) providing information on their distribution function. CXRS measurements of energetic 3He ions, a first for ASDEX Upgrade, are presented. The 3He ions are accelerated to high energies by a three-ion cyclotron resonance frequency (ICRF) heating scenario in a mixed hydrogen–deuterium plasma. The spectral signature of the energetic helium ions in the charge exchange spectra is presented and compared with the theoretical predictions obtained with the TORIC-SSFPQL code. The magnitude of the predicted charge exchange spectral radiance, obtained via forward-modelling of the spectrum utilising TORIC-SSFPQL distribution functions, and the expected energies of the ions agree well with the measurement, confirming that the spectral feature is due to ICRF-accelerated 3He ions. Comparisons between the experimental measurement and the modelling reveal discrepancies that illuminate details of the velocity distribution function of these ions.
Low-complexity eigenstates of a
ν
= 1/3 fractional quantum Hall system
Authors: Nachtergaele Bruno , Warzel Simone , Young Amanda
Published: November 2020

We identify the ground-state of a truncated version of Haldane’s pseudo-potential Hamiltonian in the thin cylinder geometry as being composed of exponentially many fragmented matrix product states. These states are constructed by lattice tilings and their properties are discussed. We also report on a proof of a spectral gap, which implies the incompressibility of the underlying fractional quantum Hall liquid at maximal filling ν = 1/3. Low-energy excitations and an extensive number of many-body scars at positive energy density, but nevertheless low complexity, are also identified using the concept of tilings.
Calculation of the thermodynamic characteristics of an upward swirling gas flow under conditions of side wind
Authors: Obukhov A G
Published: November 2020

The paper presents the results of numerical modeling of lateral wind effects on three-dimensional unsteady air flows in an upward swirling stream of an artificially created tornado after entering a stationary mode. Under the corresponding initial and boundary conditions, the solutions of the complete system of Navier-Stokes equations in the computational domain in the form of a rectangular parallelepiped are numerically obtained using the explicit difference scheme. At fixed points in time, the gas-dynamic characteristics of air flows are calculated under the action of gravity and Coriolis, as well as taking into account the constant horizontal directional wind speed. Numerical calculations showed that the resulting density, temperature, and pressure gradients lead to significant and asymmetric changes in air flows at different points in time and at different points in the computational domain. The total displacement of the vortex in the direction of the wind, the deformation and increase in the diameter of the vortex, which begin in the bottom part and pass into its vertical part, are established. In the considered range of time changes, the stability of the air vortex under study against wind action and the stable operation of the computational scheme used are noted.
Thermal impact of buried reservoirs with industrial waste of the fuel and energy complex on frozen soils
Authors: Zemenkova M Yu , Mikhailov P Yu , Shabarov A B , Shastunova U Yu
Published: November 2020

The oil and gas industry has been intensively developing in the far north of the Russian Federation. Underground tanks are repositories of waste from processed petroleum products, liquefied gas, condensate, process water, and other waste from the fuel and energy complex. High-quality underground disposal of industrial waste can eliminate leakage of chemicals into the soil and reduce the thermal effect on frozen soil. The article presents an algorithm for calculating the thermal effect of industrial “hot” waste of the fuel and energy industry on frozen soil. Heat fluxes from a 20,000 m3 tank are estimated, an area of soil thawing is calculated. An engineering solution was developed to reduce / eliminate this effect.
Use of collapsible pipelines for joint work with main oil product pipelines
Authors: Melnikov D I , Zemenkova M Yu , Podorozhnikov S Yu
Published: November 2020

The paper describes development stages for dismountable pipelines to work together with the major oil pipeline. Dismountable pipelines are used for transporting refined oil volumes over great distances in any climatic and geographical conditions. A dismountable construction provides technological pipeline schemes for rapid transportation and distribution of refined oil products to storage tanks. Subsequently, these products from containers can be utilized for various purposes.
Development of an algorithm for determining the optimal start time of oil wells to reduce the peak load
Authors: Klyuev R V , Bosikov I I , Tavasiev V Kh , Gavrina O A
Published: November 2020

The subject of this work is the development of an algorithm for determining the start time of wells in the automatic re-activation mode to save power during peak hours. This measure is relevant for the consumer and for the energy-supplying organizations, because the redistribution of load on peak hours or night zones will provide the most economically balanced operation of the enterprise, and will allow the most efficient use of sources of electrical energy supply organization. The algorithm development will provide operational control and management of the operating mode of the considered equipment in automatic mode. Besides, this will reduce the influence of the human factor on the operation of these consumers and minimize deviations in the hourly planning of electricity consumption, as well as reduce the cost of paying for consumed power. The short-term prospect of implementing this development will ensure optimal power consumption of the periodic well stock during peak load hours, and, consequently, will provide savings in the material resources of the enterprise.
Classification and features of projects in the oil and gas industry
Authors: Bovkun A S , Arkhipkin O V , Koroduk I S , Krupchenko A A
Published: November 2020

Project management has been widely used in various fields and sectors of the economy over the past years. Projects implemented in the oil and gas industry have significant differences between them. To choose the optimal approach to managing an oil and gas project, firstly, the distinctive features of the project type should be identified in advance. The use of project classification makes it possible to optimize methods and tools for managing specific projects and increase the efficiency of their implementation. The article analyzes the classification of projects. The main classification features and types of projects most commonly used in scientific literature and practice are identified. In the course of the research, it was found that the presented approaches to the classification of project management do not sufficiently take into account the branch of economy in which they are implemented. Therefore, the classification of projects in a particular sector of economy may have its own classification features applicable only to the specific industry. The oil and gas industry is considered as a separate branch of economy. The article considers the most well-known oil and gas production projects implemented in recent years. The analysis of the projects has shown there is a number of features that are different from other projects. Therefore, for detailed classification of oil and gas projects, the author’s classification features of projects significantly affecting the financial costs and timing of implementation of oil and gas projects are presented.
Preliminary zoning of negative impact of the projected oil waste polygon at the Samotlor field
Authors: Aitov I S , Khudaiberdiev A T
Published: November 2020

This paper provides a comprehensive analysis of the building expediency of a polygon for processing oil wastes in KhMAD-Yugra. Preliminary research has shown the environmentally dangerous impact of its project location relative to Nizhnevartovsk city, village Izluchinsk and village Bolshetarkhovo, as well as other important objects. The method of location estimation based on the main rules of life safety is proposed. Its application will reduce the environmentally dangerous impact and make it possible to choose the most optimal location of the polygon. An environmental pollution assessment scale has been developed, presented in tabular form for convenience. The area of zones of different dangerous influence degrees is calculated. The article describes the increase in the probability of earthquakes, wildland fires and floods in the area of the Samotlor field polygon due to global warming. The article also considers the prospect of using GIS programs in modeling environmental phenomena that affect oil and gas production facilities.
An analysis of the effectiveness of hydraulic fracturing at YS1 of the Northern field
Authors: Karpikov A V , Aliev R I , Babyr N V
Published: November 2020

There are many methods of enhanced oil recovery and stimulation of oil inflow, and in order to find their most effective application, it is necessary to study the object of works, candidate wells, as well as their impacts on these wells. One of the methods of production intensification, which makes it possible to improve profitability of oil extraction, is hydraulic fracturing.
Hydraulically perfect modes of injection of grouting mixtures when isolating absorbing formations
Authors: Chizhov A P , Andreev V E , Chibisov A V , Mukhametshin V V , Kuleshova L S
Published: November 2020

The article deals with a mechanism of isolation of absorbing intervals during the construction of oil and gas wells. Research is based on systemic approaches to complex scientific and technical problems. The results of laboratory and technological experiments aimed at improving the hydromechanical processes of cementation of absorbing rocks are presented. Various technological schemes for injecting hardening solutions into intervals of absorbing formations, the mechanism of interaction between solutions and permeable rocks, hydraulically perfect modes of injection of backfill mixtures and quality and efficiency of insulation works are analyzed.
Probabilistic statistical model for predicting the effectiveness of hydraulic fracturing
Authors: Gabdrakhmanova K F , Izmaylova G R , Samigullina L Z
Published: November 2020

The article studies the effectiveness of single-stage and multi-stage hydraulic fracturing technologies using the mathematical statistics method. The studies are based on the geological and physical characteristics of the Shirotny Priob fields which makes it possible to substantiate the methods for choosing the hydraulic fracturing technology. Based on the probabilistic and statistical analysis of field efficiency data, quantitative criteria for the selection of fracture parameters by length, height and amount of injected propane have been established. They can be used to predict the use of multi-stage and single-stage hydraulic fracturing methods. The productive horizon AS12-3 has a complex geological and physical structure and low filtration and storage properties, which complicates its development and contributes to the active formation of hard-to-recover reserves. The one-stage hydraulic fracturing technology is efficient only for 3-4 years. The multistage hydraulic fracturing technology showed is more efficient in comparison with the single-stage one.
Improving equipment and technology for selective acid treatment of wells
Authors: Khabibullin M Ya
Published: November 2020

This method is based on the following effect. A channel in the selected formation layer or section is formed by sandblasting. The acid solution is pumped into the channel through the nozzle of the perforator. The stream of acidic solution entering the channel prevents this solution from leaving the channel. In order to increase the acid depletion time, i.e. to slow down the reaction rate, it is necessary to add special reagents to the solution. Syntanol DS-10 TU 2483-016-71150986-2012 (a non-ionic surfactant used as an effective surfactant) is a very effective reaction rate reducer. Adding it in an amount of 0.5% (by weight of the volume of the solution) one can reduce the reaction rate by 2.7 times. It is much more difficult to increase the rate of acid solution injection into highly drained formations of low-production wells (up to 5–10 tons of fluid per day) with a low reservoir pressure due to the insufficient capacity of acid aggregates.
Developing the efficiency of low-productivity oil deposits via internal flooding
Authors: Soloviev N N , Mukhametshin V Sh , Safiullina A R
Published: November 2020

The article studies geological and technological parameters’ impact on degree and nature of production wells. The wells influence the water injection into wells in the carbonate reservoirs of the Tournaisian stage of the Birsk saddle. The study presents an algorithm with substantiating technological solutions to increase the efficiency of developing low-productive deposits via internal flooding. It also considers the development of facilities for hard-to-recover reserves with high production costs and low profitability. This is made in order to use the resource base of the Volga-Ural oil and gas provinces more efficiently.
Improved handling of 4x4 vehicles with differential transmission in curved driving on support surfaces with low coupling properties
Authors: Zhileykin M
Published: November 2020

Studying the trends in the development of modern automotive industry, you can see that manufacturers are constantly increasing the level of control over the parameters of the movement of wheeled vehicles, achieving the maximum level of stability and controllability of cars. The purpose of this work is to improve the handling of vehicles with a 4x4 wheel formula with a differential transmission in curved motion on support surfaces with low coupling properties. An algorithm is proposed to improve the handling of vehicles with a 4x4 wheel formula with a differential transmission in curved motion on support surfaces with low coupling properties due to braking of individual wheels. The efficiency and efficiency of the proposed algorithm is proved by the methods of simulation of the movement of two-axle cars with a 4x4 wheel formula with a differential transmission.
Optimization of the flow part of the pump for abrasive-containing liquids by hydrodynamic modeling methods
Authors: Martynyuk O , Petrov A
Published: November 2020

Abstact. In this article the severe operating conditions of pumps for abrasive media, as well as the complexity of obtaining an analytical solution to the wear problem are described. Optimization criteria for such pumps are selected. A mathematical model for calculating a ground pump is presented. The STAR CCM+ software package modeled 15 models with different geometries and identified the main geometry parameters that affect the rate of erosion. A weight function was created that characterizes the success of model optimization based on the selected criteria. According to the accepted parameters, 20 models were modeled and the best geometric dimensions of the flow part were selected. The results are analyzed and conclusions are drawn.
Quasi-static bending of thin-walled beams with different fillers under extreme load for solving the problems of crashworthiness
Authors: Goncharov R , Zuzov V
Published: November 2020

In this paper, there are issues related to the choice of elemental modelling of thin-walled beams with various types of fillers for quasi-static bending loading, which causes washing of beams and filler, as applied to the optimal design. The objects of research are thin-walled beams made of aluminium AMG6 contains fillers made of aluminium foam, epoxy resin and composite (consisting of Poraver balls and epoxy resin). One of the best fillers for solving the problems of crashworthiness is requiring expensive technological equipment for filling. Epoxy resin is a fragile material, but inexpensive, affordable and technologically “convenient”. In addition to the influence of the filler on the mechanical properties of beams, the effects of the constrained behaviour of the material of the filler under the bending loading of beams are investigated with Zwick Z100 (for hollow thin-walled beams made of aluminium and the same beams with fillers).The paper presents the results of numerical calculations and the results of the experiment (the error of calculations does not exceed 8%).The most rational is the ratio between the indicators of energy intensity - the mass is aluminium-foam (with an increase in the mass of the sample by 2,1 times the mechanical properties reach 10 of times). The remaining fillers give significantly worse results for the same parameters. To assess the effectiveness of the use and creation materials for the refinement of the cabins and car bodies according to the crashworthiness.
Overview of methods for optimizing the flow of the centrifugal pump
Authors: Gradilenko N , Lomakin V
Published: November 2020

Abstact. This article is devoted to a review of the flow part of the centrifugal pumps(CFP), as well as methods for its optimization. The components of the flow part (inlet, impeller and outlet) were considered, and methods for their optimization were given. The analysis of the literature was carried out. Conclusions are drawn on the development and improvement of vane pumps.
Thermal processes in the electromechanical mandrel of holes in steel billets
Authors: Morozov A , Fedotov G , Ivanova Y , Khabieva L , Knyurov A
Published: November 2020

The article presents findings on the distribution of temperature fields during Electromechanical mandreling (EMM) of holes in the surface of the workpiece and the tool. The design temperatures significantly exceed the phase transformation temperatures, but the melting of structural components in the surface layer of the workpiece does not occur due to high cooling rates. It is not possible to fix the maximum process temperatures experimentally due to their short duration of action.
Ensuring the performance of equipment during the warranty period of operation
Authors: Kushnarev S
Published: November 2020

Annotation. The problem of increasing the reliability of domestic technological machines and equipment remains relevant and requires a speedy solution in the current conditions of acute competition in the market of equipment and technologies. The low level of reliability of equipment reduces the efficiency of using machines and the quality of their technological processes, increases operating costs. The solution of this problem, as the results of research show, is impossible without participation in ensuring the operability of technological machines and equipment of manufacturers of modern domestic equipment. Providing engineering and technical support for manufactured machines, taking part in technical service, equipment manufacturers have the opportunity to study the reasons for the low reliability of units, units, connections and take measures to exclude their appearance. By setting the wear rate of the working surfaces of the critical interfaces in real-world operating conditions of the machine, it becomes possible to control its reliability and efficiency
Increasing the creative potential of production in the context of prevailing trends
Authors: Ganina G , Mukhin A , Ostrovsky Yu , Yakovleva A
Published: November 2020

Abstact. The article examines the prevailing trends in modern production and their role in forming ideas about further development. It is shown that involvement in the process of understanding the trends of the regularity of labor activity transformation leads to an understanding of the place of self-development in the production strategy. A comprehensive analysis of trends, combined with the use of new approaches to the description of labor activity, helped to reveal and justify a new view of the strategy for improving production. This made it possible to describe at the conceptual level a new type of production systems, namely self-developing production systems. The presence of a model of real transformation of labor activity in the description of such production makes it possible to create a system with an internal self-development device. Such self-developing production systems do not need external influences and are invariant in a variety of social environments.
Variable speed control in centrifugal pumps for closed systems
Authors: Petrov A , Leonardo Gomez Dias Rafael
Published: November 2020

Energy consumption in any type of installation, whether for urban purposes, commercial or industrial, is a very important question; therefore, reducing energy consumption is of great importance. It is very important to control the rotational speed of the pumping equipment in accordance with the required consumption or requirement. For closed circuits (closed systems) it is important to ensure the required flow rate while maintaining the proper pressure or working head in centrifugal pumps. This type of control is ideal for installations with changeable curves, where different work processes are required at the same pressure or different process pressures in centrifugal pumps.
Types of heat exchangers in industry, their advantages and disadvantages, and the study of their parameters
Authors: Edreis Edreis , Petrov A
Published: November 2020

Annotation The heat exchanger as the main element in various types of energy complex is widely studied in technological and production processes. Heat exchangers are classified according to their application. Therefore, in this article we will consider the main types of heat exchange equipment, the choice of a specific type, depending on temperature, flow, pressure drop, and so on. The paper also provides a brief description of software for calculating, modeling and designing CFD, the advantages of each of the methods used to study heat transfer and its efficiency.
Mathematical modeling and analysis of the influence of various regulators on the quality of the transient hydraulic drive with throttle control.
Authors: Protopopov A , Gontarev A , Manenak Ya
Published: November 2020

This article provides an analysis of transients in various hydraulic drive regulators. Hydraulic drives are widely used in a number of areas of power engineering and other types of equipment, which is due to a number of advantages, such as: small size and weight with high energy consumption, high speed, high positioning accuracy, a wide range of operating pressures and speeds of executive bodies.
Austenite to Ferrite Transformation in Fe – 9 %Cr Alloys. II. Determination of Growth Rates
Authors: Mirzaev D A , Yu Okishev K , Lapina I V
Published: November 2020

The paper continues theoretical analysis of austenite to ferrite transformation in an Fe-9 %Cr alloy demonstrating a typical site-saturation behaviour under the condition of diffusionless growth of a phase. In the previous paper the K coefficient in the Avrami equations being the asymptotes of Calm’s solution of the site-saturation transformation kinetics was used that contained a constant activation energy indicating the small value of the work of critical nucleus formation. This approach permitted to determine activation energy of transformation that was found to be equal to about 300 kJ/mole. In the present paper a new method of finding Calm’s equation coefficients from bending point at isothermal curves plotted on double logarithmic scale is proposed. Actually this bending point is the intercept of the two above-mentioned asymptotes of the Cahn’s curve, and equating the formulae describing theses asymptotes allows to find the coefficients in question. Given the average austenite grain size, it permits to find numerical values of growth rates. The activation energy thus acquires the exact physical meaning of the energy barrier at the interphase interface; its value was found to be 286 kJ/mole, which is close to previous results. The growth rates were thus determined as a function of temperature and the TTT diagram for the alloy is calculated that shows close correspondence with experiment.
Investigation of the Effect of Sulfide Inclusions on the Hydrogen Separation of Metal
Authors: Nasibullina O A , Rizvanov R G
Published: November 2020

In the presence of an increased concentration of hydrogen, premature destruction of the metal occurs. Hydrogen brittleness is caused by imperfection of the crystal lattice of metals. Distinguish between hydrogen corrosion caused by molecular hydrogen and hydrogen corrosion caused by atomic hydrogen. The presence of hydrogen in a metal increases the fragility of all metals, without exception. Hydrogen accumulates in traps (vacancies, dislocations). The segregations of carbon and other impurity atoms at grain boundaries enhance the ability of iron to capture hydrogen. Atomic hydrogen resulting from electrochemical reactions penetrates steel at normal temperature, causing it to stratify. Molecular hydrogen generated during the processing of hydrocarbons, electrolysis of water, violation of welding technology, penetrates into steel only at temperatures above 200 °C. The aim of the work was to determine non-metallic inclusions using the metallographic method. The authors also determined the presence of sulfide accumulation in the studied metal of the pipe. It is noted that the amount of sulfide inclusions is approximately the same, both near the metal stratification and on the base metal of the sample.
Rolled Stock Structure Preparation for Cold Forging of Pearlite Steel Grades
Authors: Pachurin G V , Fillipov A A , Mukhina M V
Published: November 2020

Special requirements are applied to the structural-mechanical characteristics of rod bolt products manufactured by cold die forging of pearlite steel class. A very common and productive method of obtaining finished metal products with high mechanical properties is their landing on cold heading (cold-heading) machines made of rolled metal, which must have a certain quality along the entire length: a sufficient ductility, homogeneous structure and parameters of technological properties, absence of any defects. Hardware plants receive the initial blank for the manufacture of various fasteners in the form of hot-rolled steel, which is not possible to use for the landing of high-strength hardware, due to the poor quality structure and surface layer. Therefore, the calibrated rolled stock is subjected to intermediate heat treatment before driving, which should guarantee the quality of the metal products at transitions of the cold heading. Further, the driven products of strength class 8.8 and up, made of alloy steel grades, must be subjected to hardening with subsequent tempering. However, such thermal operation often leads to decarburization of the surface, cracking and warping of finished products, thus increasing labor intensity, energy consumption and, consequently, the final production cost. The paper proposes an alternative method of the rolled stock structural preparation, which includes isothermal treatment of pearlite steel grades 35X and 38X, which excludes from the technological process the recrystallization annealing and quenching with the release of finished bolt products, and which minimizes any appeared scratches, warping and decarburization on the rolled stock and the rolled product. The structure of rolled stock induced in the drawing die, and the surface hardening by reduction, and thread rolling provide the parameters of mechanical properties of M8 bolts and pins, corresponding to the strength class 9.8.