bluuebunny/crossref_metadata_2025 huggingface dataset:
Prediction of Reservoir Properties from Seismic Data by Multivariate Geostatistics Analysis
Authors: Bezkhodarnov Vladimir V. , Chichinina Tatiana I. , Korovin Mikhail O. , Trushkin Valeriy V.
Published: October 2021

A new technique has been developed and is being improved, which allows, on the basis of probabilistic and statistical analysis of seismic data, to predict and evaluate the most important parameters of rock properties (including the reservoir properties such as porosity and permeability), that is, oil saturation, effective thicknesses of reservoirs, their sand content, clay content of seals, and others; it is designed to predict the reservoir properties with sufficient accuracy and detail, for subsequent consideration of these estimates when evaluating hydrocarbon reserves and justifying projects for the deposits development.

Quantitative reservoir-property prediction is carried out in the following stages:

– Optimization of the graph ("scenario") of seismic data processing to solve not only the traditional structural problem of seismic exploration, but also the parametric one that is, the quantitative estimation of rock properties. – Computation of seismic attributes, including exclusive ones, not provided for in existing interpretation software packages. – Estimation of reservoir properties from well logs as the base data. – Multivariate correlation and regression analysis (MCRA) includes the following two stages: Establishing correlations of seismic attributes with estimates of rock properties obtained from well logs. Construction of multidimensional (multiple) regression equations with an assessment of the "information value" of seismic attributes and the reliability of the resulting predictive equations. (By the "informative value" we mean the informativeness quality of the attribute.) – Computation and construction of the forecast map variants, their analysis and producing the resultant map (as the most optimal map version) for each predicted parameter. – Obtaining the resultant forecast maps with their zoning according to the degree of the forecast reliability.

The MCRA technique is tested by production and prospecting trusts during exploration and reserves’ estimation of several dozen fields in Western Siberia: Kulginskoye, Shirotnoye, Yuzhno-Tambaevskoye, etc. (Tomsk Geophysical Trust, 1997-2002); Dvurechenskoe, Zapadno-Moiseevskoe, Talovoe, Krapivinskoe, Ontonigayskoe, etc. (TomskNIPIneft, 2002–2013).
Specification of the Geological Structure of the Inter-Salt Sediments of the Savichskoye Area Based on the Results of Well N

o

10S2 Drilling and Performing 3D Seismic Surveys in Order to Assess the Prospects for Identifying Hydrocarbons in Low-Permeability Reservoirs
Authors: Tsyhankou Andrei , Kanyushenka Alyaksandr , Hrudzinin Alyaksandr , Kudrashou Alyaksei
Published: October 2021

The results of the well 10s2-Savichskaya drilling, laboratory core research are set out. Based on the results of integration the latest methods of wire line survey, laboratory core samples research, seismic facies analysis, typical lithotypes of the Savichsko-Bobrovichi area rocks were identified, reservoir features were predicted, the prospects of inter-salt deposits for identifying accumulations of hydrocarbons in unconventional reservoirs were substantiated. A perspective zone was identified and recommendations for drilling a pilot bore were given.
Integrating Horizontal Wellbores When Building a Geological Model of an Offshore Field
Authors: Kokareva Oksana Vasilievna , Miryasova Yana Andreevna , Alekseeva Tamara Aleksandrovna
Published: October 2021

With the advent of the equipment for full well logging suite in the horizontal wells, it became possible to evaluate the reservoir's quantitative parameters. However, the original curves are mainly used for this purpose, which leads to significant errors, in particular due to the significant influence of nearby reservoirs on the tools readings in the penetrated deposits.

There is a need to discuss the current issues of interpretation in directional, horizontal and multi-lateral wells with the experts.

3DP module in the downhole software platform* allows to evaluate the overall influence of geometric effects, as well as to adjust logging curves for the influence of several reservoirs on the logging tools responses, which are not still taken into account by conventional methods when processing.

The modeled density image is especially useful for confirming the model geometry, updating the local dip angle, and identifying areas, where additional features, such as thin layers, are to be added. The accounting for density and neutron porosity for layers in the petrophysical analysis increases the efficiency of calculating clay volume and porosity, which affects the saturation.

The authors also proposed a methodology for assessing share of sand component based on RHOB image. Further accounting of NTG, for the correct assessment of the reservoir properties in a heterogeneous reservoir, followed by the data accounting in the geological model.

The results obtained in the course of the work allowed to apply the spatial interpretation of horizontal well in geological modeling, as well as to improve the interpretation algorithm.
Digitization of the Upstream Data Shared from the Private Sector to the Government Sector
Authors: Ashkanani Abdullah , Rashed Hessa , Al-Ohali Dalal , Al-Ansari Bedour , Al-Ibrahim Balqees , Al-Bader Rakan , Sadiq Bashayer , Hassan Mohammad , Abalkhail Haya
Published: October 2021

The Ministry of Oil (MOO) is going with new task to realize the New Kuwait Vision, and so, MOO is on track to shift to a complete digital work environment. Preliminary steps toward the transformation arose with a high concern of connecting with one of the main stakeholders, the Kuwait Oil Company. All in optimism to modernize the data digitally between the Kuwait Oil Company and the Ministry of Oil when it comes to the Technical papers proposal.

Based on such, many more motives appeared to modify the work process from manual to digital. Therefore, crucial plans were established based on calculated plans set by managerial personnel to group delegated tasks. As an outcome, the staff with recognizable capabilities dispersed these tasks and executed most using current applications.

In the ancient systems, papers that used to take around 21 working days to be reviewed from start to finish, now in a days with the digital system, take around 3 days only, saving a lot of time and resources for each technical paper that is submitted through this new and improved system.

Of course, guaranteeing a paperless route brought about many challenges and worries. The most important of them being the reassurance of security measures to protect personnel and the data sharing process. Additionally, the reception of senior workforces to change habits and relearn new procedures of producing daily tasks, as well as, increasing the capability through training courses and supervision. Furthermore, tackling errors exposed within the system through trial and error to boost the experience and optimize workflow.
Efficiency Criteria of Operations in the Marine Resuce Support for Hydrocarbons Production and Transportation in the Arctic Zone of the Russian Federation
Authors: Lapteva Tatyana Ivanovna , Kopaeva Lyudmila Anatolyevna , Mansurov Marat Nabievich , Efremov Vladimir Ivanovich , Ilyuhin Viktor Nikolayevich
Published: October 2021

The creation of an effective system of rescue support (the abbreviation ASO is adopted on the territory of the Russian Federation) in the implementation of the processes of oil and gas production and transportation in the Arctic seas of Russia is an urgent and difficult task. The feasibility of creating such a system for offshore oil and gas production facilities is due to the statistics of accidents and incidents at such facilities, as well as the fact that the Merchant Shipping Code of the Russian Federation, in essence, does not consider the applicability of the existing system of rescue operations on platforms that are exploring and developing mineral and other non-living resources the seabed and its bowels.

The successful solution of numerous problems of rescue support, including the requirements for the quality of the system, indicators and criteria for the effectiveness of the operations carried out, can be significantly increased by using mathematical models that make it possible to identify patterns in the processes of performing urgent work, improve the quality of planning, and, consequently, the efficiency of management of various organizational systems. Applied in many areas of activity, the scientific direction "research of operations" is advisable to use when system generation of rescue support within the framework of improving the system of technical regulation of oil and gas enterprises.

Determining the effectiveness of a purposeful process quantitatively will allow, on a scientific basis, with the involvement of modern mathematical methods, to solve the problem of increasing the effectiveness of the use of forces and means of the marine rescue support, including the functioning of the emergency support system in the mode of daily and emergency activities, as well as the preparation of the necessary forces and means.

The novelty of the presented work lies in the application of the provisions of the theory and the apparatus of operations research to assessing the effectiveness of the system of the marine rescue support, which will further serve as a methodological basis for the development of a number of documents and provisions that are of practical importance: methods, requirements for the system of rescue support, documents in the field of control over the rescue system, etc.
Digital platform for E&P Assets Business Process Optimization with a Module for Estimation and Optimizing of Greenhouse Gases Emissions. Case Study
Authors: Tokarev Denis , Tailakov Dmitry , Ablaev Anton
Published: October 2021

Resume

Due to the increasing requirements for reducing the carbon footprint on the part of end users of hydrocarbons, there is a need to develop a system for automated analysis of the main business processes of oil and gas field development to assess greenhouse gas emissions, as well as for optimization in order to improve environmental safety. The paper describes a prototype of a platform that was developed for decarbonization of oil and gas enterprises using modern optimization tools and up-to-date methods for inventory of greenhouse gas emissions.

The platform is based on the following models:

– simulation model (IM) – simulates the company's business processes, identifying weaknesses and areas of potential development, is a set of mathematical algorithms for solving direct problems; – optimization model (OM) – allows to conduct a comprehensive analysis with a large number of parameters, excluding manual data processing and using automated information exchange between various software that is used in the oil and gas industry for modeling and monitoring of various processes, as well as developing various development options (taking into account geological conditions, geophysical interpretation, etc.). The initial conditions and the specified criteria related to economic indicators allow to solve the problem of finding the optimal parameters for the development of the selected asset.

This paper shows the economic effect of implementing software based on a digital twin, implemented as a platform with the ability to build a model of an oil and gas asset, using various data (SAP, 1C, IPM GAP, Repos, Eclipse, etc.) and targets for the development. In the same way, the possible losses of the oil and gas industry from the introduction of additional carbon taxation and the potential for optimizing processes to minimize these costs are considered. IPCC methods are used to calculate greenhouse gas emissions, and direct, indirect, and fugitive emissions are considered in the calculation. The main conclusion is the need to reduce the costs for oil and gas companies and prepare modern automated digital solutions for accounting for greenhouse gas emissions in advance to achieve a zero-carbon footprint and maintain the competitiveness of the Russian oil and gas industry.

As a result of the work done, the feasibility was justified, and the result was demonstrated to the customer for calculating greenhouse gas emissions based on digital twins of key business processes of oil and gas enterprises. The use of automated systems makes it possible to reduce the potential economic risks associated with the introduction of a carbon fee from large oil and gas consumers.
Direct Energy Minimization Algorithm for Numerical Simulation of Carbon Dioxide Injection
Authors: Khakimova Lyudmila , Isaeva Anna , Dobrozhanskiy Vladimir , Podladchikov Yury
Published: October 2021

We discuss numerical simulation of carbon dioxide injection considered by oil and gas companies. Complex behavior of multicomponent reservoir fluids mixed with carbon dioxide may cause the occurrence of vapor-liquid-liquid equilibria (VLLE), salt precipitation in aquifers, pore-clogging, etc. We propose a simple algorithm for phase equilibria calculations based on the minimization of the multicomponent system free energy. This algorithm can be used to calculate phase separations and component partitioning between the phases under various conditions (critical region, two- and three-phase equilibria, etc.). We demonstrate the applicability of the proposed algorithm in a series of calculations. We consider binary and ternary mixtures that include carbon dioxide and hydrocarbons. We examine the algorithm in two- and three-phase equilibrium calculations and compare its performance with the popular iterative fugacity equilibration technique. We show that both calculation techniques give near-identical results for the considered mixtures. Thus, we show that the free energy minimization algorithm can be used interchangeably with the fugacity equilibration technique for calculating phase equilibria. This algorithm is applicable for VLLE calculations, which is important when considering multicomponent reservoir fluids that include carbon dioxide.
Investigation of CO2 Utilization Processes on Metal-Containing Fillers with Generation of Hydrogen and Hydrocarbons
Authors: Garifullina Chulpan Aydarovna , Ibragimov Ildar Ilyasovich , Indrupskiy Ilya Mikhailovich , Klimov Dmitriy Sergeevich , Zakirov Ernest Sumbatovich , Sakhabutdinov Rifkhat Zinnurovich
Published: October 2021

Continuing consumption of fossil fuels around the world, which has led to an increasing concentration of carbon dioxide CO2 in the atmosphere and global climate change caused by greenhouse gases, has become one of the main challenges for humanity. Heterogeneous catalytic hydrogenation of carbon dioxide in order to obtain valuable carbon-containing products and materials is one of the decarbonization directions. There is much research in the world dedicated to the hydrogenation of CO2 to various hydrocarbons, such as methane, lower olefins, long-chain hydrocarbons, formic acid, methanol and higher alcohols, which are produced by catalytic reactions with various mechanisms. There are still significant challenges associated with the need for an external source of hydrogen, high process temperatures, and the development of active, selective, and stable catalysts that would be suitable for large-scale production.

This paper presents results of research on a CO2 utilization method with hydrogen and hydrocarbons production – the transformation of wastes into a source of energy, which allows solving environmental and energy problems. The method described in this paper consists in the interaction of metallic fillers with water saturated with carbon dioxide in a reactor at low (room) temperatures and further analysis of the resulting gas mixture using a chromatograph.

Qualitative and quantitative evaluation of the produced gas composition, study of the effect of reaction system volume, filler composition and structure, and process temperature on the reaction product yield are presented. The results of theoretical and experimental analysis of the reactions underlying the process are given, and the economic potential of the proposed laboratory method is evaluated.
Investigation of Underground Bio-Methanation Using Bio-Reactive Transport Modeling
Authors: Nikolaev Denis Sergeevich , Moeininia Nazika , Ott Holger , Bueltemeier Hagen
Published: October 2021

Underground bio-methanation is a promising technology for large-scale renewable energy storage. Additionally, it enables the recycling of CO2 via the generation of "renewable methane" in porous reservoirs using in-situ microbes as bio-catalysts. Potential candidate reservoirs are depleted gas fields or even abandoned gas storages, providing enormous storage capacity to balance seasonal energy supply and demand fluctuations. This paper discusses the underlying bio-methanation process as part of the ongoing research project "Bio-UGS – Biological conversion of carbon dioxide and hydrogen to methane," funded by the German Federal Ministry of Education and Research (BMBF). First, the hydrodynamic processes are assessed, and a review of the related microbial processes is provided. Then, based on exemplary field-scale simulations, the bio-reactive transport process and its consequences for operation are evaluated.

The hydrogen conversion process was investigated by numerical simulations on field scale. For this, a two-phase multi-component bio-reactive transport model was implemented by (Hagemann 2018) in the open-source DuMux (Flemisch et al. 2011) simulation toolkit for porous media flow. The underlying processes include the transport of reactants and products, consumption of specific components, and the related growth and decay of the microbial population, resulting in a bio-reactive transport model. The microbial kinetic parameters of methanogenic reactions are taken from the available literature. The simulation study covers different scenarios on conceptional field-scale models, studying the impact of well placement, injection rates, and gas compositions.

Due to a significant sensitivity of the simulation results to the bio-conversion kinetics, the field-specific conversion rates must be obtained. Thus, the Bio-UGS project is accompanied by laboratory experiments out of the frame of this paper.

Other parameters are rather a matter of design; in the present case of depleted gas fields, those parameters are coupled and can be chosen to convert fully hydrogen and carbon dioxide to methane. Especially the well spacing can be considered the main design parameter in the likely case of a given injection rate and gas composition.

This study extends the application of the previously developed code from a homogeneous-2D to the heterogeneous-3D case. The simulations mimic the co-injection of carbon dioxide and hydrogen from a 40 MW electrolysis.
Informative Value and Interpretation Reliability of Wide Frequency Range Acoustic Noise Technique in Operating Horizontal Wells
Authors: Yarullin Rashid Kamilevich , Valiullin Rim Abdullovich , Yarullin Airat Rashidovich , Mihailov Dmitry Nikolaevich , Shako Valery Vasilyevich , Bikkulov Marsel Minullovich
Published: October 2021

This paper is devoted to the problem of informative value and interpretation reliability of wide frequency range acoustic noise technique in operating horizontal wells considering results of laboratory experiments conducted with wellbore mockups. The set of factors affecting the spectrum of acoustic noise recorded in wellbore were experimentally investigated and the necessity for calibrating of noise logging tools to provide results of acoustic measurements in the unified scale is also discussed.
Implementation of Vendor-Independent Stochastic Inversion for Improving Quality and Efficiency of Well Placement on the Field of Novatek Company
Authors: Nemushchenko Danil Andreevich , Shpakov Pavel Vladimirovich , Bybin Petr Valerievich , Ronzhin Kirill Viktorovich , Sviridov Mikhail Vladimirovich
Published: October 2021

The article describes the application of a new stochastic inversion of the deep-azimuthal resistivity data, independent from the tool vendor. The new model was performed on the data from several wells of the PAO «Novatek», that were drilled using deep-azimuthal resistivity tools of two service companies represented in the global oilfield services market.

This technology allows to respond in a timely manner when the well approaches the boundaries with contrasting resistivity properties and to avoid exit to unproductive zones. Nowadays, the azimuthal resistivity data is the method with the highest penetration depth for the geosteering in real time.

Stochastic inversion is a special mathematical algorithm based on the statistical Monte Carlo method to process the readings of resistivity while drilling in real time and provide a geoelectrical model for making informed decisions when placing horizontal and deviated wells. Until recently, there was no unified approach to calculate stochastic inversion, which allows to perform calculations for various tools. Deep-azimuthal resistivity logging tool vendors have developed their own approaches. This article presents a method for calculating stochastic inversion. This approach was never applied for this kind of azimuthal resistivity data. Additionally, it does not depend on the tool vendor, therefore, allows to compare the data from various tools using a single approach.
Applying of Robotic Equipment to Perform Production Logging Operations in Extended Horizontal Exploration Wells Equipped with the Y-Tool System
Authors: Morozov Oleg Nikolaevich , Andriyanov Maksim Alexandrovich , Ivlev Mikhail Sergeevich , Koloda Alexey Vladimirovich , Gabdullin Aydar Razinovich , Agadullin Vadim Akramovich
Published: October 2021

This article describes the implementation process for use of robotic equipment to perform production logging in extended horizontal production wells equipped with a Y-Tool bypass system. The article describes in detail the process of searching for technological solutions from bench tests to the introduction of technology in the field.

The described technology allowed the Company to find a solution to work with the Y-Tool bypass system in the production wells of the Prirazlomnoye field.
Control Over the Fracture in Carbonate Reservoirs as a Result of an Integrated Digital Stimulation Approach to Core Testing and Modeling
Authors: Yudin Alexey , Khan Abdul Muqtadir , Romanovskii Rostislav , Alekseev Alexey , Abdrazakov Dmitry
Published: October 2021

The oilfield industry is rapidly changing towards reduced CO2 emissions and sustainability. Although hydrocarbons are expected to remain the leading source for global energy, costs to produce them may become prohibitive unless new breakthrough in technology is established. Fortunately, the digital revolution in the IT industry continues at an accelerating pace. A digital stimulation approach for tight formations is presented, using the achievements of one industry to solve the challenges of another.

The fracture hydrodynamics and in-situ kinetics model is incorporated in the advanced simulator together with the detailed multiphysics models based on acid systems digitization, including rheology and fluid- carbonate interactions data obtained from the laboratory experiments. Digitization of fluid-rock interaction and fluid leakoff was performed using a coreflooding setup that allowed pumping concentrated acids in core samples at high-pressure/high-temperature (HP/HT) conditions. Varying the testing parameters across a broad range allowed refining the model coefficients in the simulator to obtain high accuracy in the predicted results.

The digital slot concept was used to validate physical models in an iterative experimental approach. The software proved efficient at providing validation of multiphysics models used together with advanced slurry transport in the simulator. The fine computational grid allowed accurate predictions of the fracture geometry, etched width, and channel conductivity, resulting in realistic well productivity anticipations. Since multiple fluid systems of the acid stimulation portfolio were digitized and incorporated into the simulator, it was possible to optimize complex acid fracturing designs in the real field operations that included retarded single-phase and multiphase acid systems, self-diverting viscoelastic acids, and fiber- based diverting systems. Several case studies from multiple areas and reservoirs from Caspian and Middle East areas have demonstrated extremely positive oil and gas production results with reduced acid volumes with the digital stimulation workflow compared to conventionally stimulated offset wells.

The digital stimulation workflow brings a new approach to acid fracturing optimization based on an integrated cycle in which high-resolution data from several sources are processed by powerful computing capacities. Starting from digitizing acid reactions with the core samples, through digitized rheology and particle transport in multiphysics models, an advanced numerical simulator tailors an optimum design from a number of acid system options, pumping rates, additive concentrations, and stage volumes to achieve best geometry of etched channels inside a fracture.
Development of Fracturing Fluids Based on Acrylamide Copolymers and Study of Their Physical and Technological Properties Using the Oscillatory Rheometry Methods
Authors: Kazak Maksim Vasilyevich , Panin Sergey Igorevich , Valenkov Andrei Mikhailovich , Hiliazitdzinau Tsimur Donalovich
Published: October 2021

This work studies the rheological properties of aqueous solutions of acrylamide copolymers. The prevailing role of elastic properties over viscous properties in predicting the proppant suspension capacity of the resulting fracturing fluid is shown. Furthermore, the potential of the use of oscillatory rheometry for studying fracturing fluid stability is demonstrated.
Multistage Hydraulic Fracturing of the Tyumen Suite Reservoirs of Em-Yogovskoye Field: Frac-Design, Practice, Results
Authors: Samoilov Mikhail Ivanovich , Astafyev Vladimir Nikolaevich , Musin Evgeny Faritovich
Published: October 2021

The paper describes a system of approaches to the design and engineering support of multistage hydraulic fracturing:

A method of developing multiple-option modular design of multistage hydraulic fracturing which is a tool for operational decision-making in the process of hydraulic fracturing. Building a Hydraulic Fracturing Designs Matrix when optimizing field development plans. The result was used to build decision maps for finding well completion methods and selecting a baseline hydraulic fracturing design.

The paper also describes how the systematization of approaches, methodological developments, and decision templates can help in optimizing field development by drilling directional and horizontal wells followed by multi-stage hydraulic fracturing. The sequence of events and tasks that led to the development of the methodology, as well as its potential, is briefly described.

The methodologies were developed during the execution of a hydraulic fracturing project at JK 29 reservoirs of the Tyumen Suite of Em-Yogovskoye field, after which they were applied in a number of other projects for the development of hard-to-recover hydrocarbon reserves in West Siberia.
High-Resolution and Multimaterial Fracture Productivity Calculator for the Successful Design of Channel Fracturing Jobs
Authors: Chuprakov Dimitry , Belyakova Ludmila , Glaznev Ivan , Peshcherenko Aleksandra
Published: October 2021

We developed a high-resolution fracture productivity calculator to enable fast and accurate evaluation of hydraulic fractures modeled using a fine-scale 2D simulation of material placement. Using an example of channel fracturing treatments, we show how the productivity index, effective fracture conductivity, and skin factor are sensitive to variations in pumping schedule design and pulsing strategy.

We perform fracturing simulations using an advanced high-resolution multiphysics model that includes coupled 2D hydrodynamics with geomechanics (pseudo-3D, or P3D, model), 2D transport of materials with tracking temperature exposure history, in-situ kinetics, and a hindered settling model, which includes the effect of fibers. For all simulated fracturing treatments, we accurately solve a problem of 3D planar fracture closure on heterogenous spatial distribution of solids, estimate 2D profiles of fracture width and stresses applied to proppants, and, as a result, obtain the complex and heterogenous shape of fracture conductivity with highly conductive cells owing to the presence of channels. Then, we also evaluate reservoir fluid inflows from a reservoir to fracture walls and further along a fracture to limited-size wellbore perforations. Solution of a productivity problem at the finest scale allows us to accurately evaluate key productivity characteristics: productivity index, dimensional and dimensionless effective conductivity, skin factor, and folds of increase, as well as the total production rate at any day and for any pressure drawdown in a well during well production life.

We develop a workflow to understand how productivity of a fracture depends on variation of the pumping schedule and facilitate taking appropriate decisions about the best job design. The presented workflow gives insight into how new computationally efficient methods can enable fast, convenient, and accurate evaluation of the material placement design for maximum production with cost-saving channel fracturing technology.
Initial Experience with Subchondral Stabilization for Bone Marrow Lesions of the Midfoot and Forefoot
Authors: Matthews Michael , Klein Erin , Weil Lowell , Sorensen Matthew , Fleischer Adam
Published: October 2021

Disabling foot pain is often accompanied by MRI evidence of bone marrow edema which may represent early structural fatigue. Emerging evidence suggests subchondral stabilization with injectable calcium phosphate can alleviate pain associated with bone marrow edema in the hindfoot, ankle and knee; however, there is no data supporting its use or safety for midfoot or forefoot lesions. We identified 54 patients who underwent SS of various midfoot/forefoot osseous structures in our practice over a four-year period. All patients proved recalcitrant to standard conservative measures, and all had advanced imaging appreciating BME. VAS for pain at 1, 3, 6, and 12 months postoperatively served as the primary outcome measure. 41 patients were included with a mean age of 54.3 ± 14.9 years and mean follow up of 14.1 ± 6.9 months. Patients saw a significant decrease in VAS pain as early as 1 month postoperatively (p<0.05). Mean postoperative VAS at 12 months was 2.11 ± 2.50, and the mean reduction in VAS pain from preop to 12 months postop was -5.00 (95% CI -3.44 to -6.56, p<0.05). Fourteen patients (34%, 14/41) were pain free at 12 months. Treatment of more than one bone (unadjusted OR 6.23 [95% CI 1.39 to 27.8], P=0.017) was associated with a greater likelihood of not achieving a pain free status at 12 months. Initial experience suggests that SS was both safe and effective in our patient population. Simultaneous treatment of multiple bones should be entered into with caution, and further research on the subject is necessary. Level of Evidence: IV (Retrospective Case Series)
Research on Percolation Threshold of Broadband Electromagnetic Wave Absorbing SiCN (MWCNTs) Composite Ceramics
Authors: Wang Shan , Gong Hongyu , Qi Desheng , Ashfaq M. Zeeshan , Yue Xigui
Published: October 2021

A simple polymer derivation method was applied in this paper to prepare a series of SiCN (MWCNTs) composite ceramics by adjusting the mass ratio of multi-walled carbon nanotubes (MWCNTs). The percolation threshold of the corresponding MWCNTs addition amount when SiCN(MWCNTs) composite ceramics exhibit the optimal electromagnetic wave (EWM) absorption performance was studied, the effect of different addition amounts of MWCNTs on reflection loss (RL), effective absorption bandwidth (EAB), electromagnetic parameters, impedance matching parameters (Z) and attenuation coefficient (α) of composite ceramics was analyzed, and the EMW absorption mechanism of the corresponding composite ceramics when MWCNTs addition amount fix at percolation threshold was discussed. The results showed that composite ceramics exhibited the best EMW absorption performance when the addition amount of MWCNTs reached the percolation threshold (10wt%): the minimum reflection loss (RLmin) was -37.9 dB, and the EAB was 2.8 GHz at a thickness of 2.4 mm; its RLmin was -21.7 dB, and the EAB reached 4.7 GHz at a thickness of 1.7 mm. By changing the sample thickness from 1.0 mm to 5.0 mm, the EAB containing the C, X and Ku bands can be acquired. Therefore, it is expected to be a promising candidate for the new generation of EMW absorbers due to its light weight, high efficiency and broad band.
MEMOIRS OF MEMBERS OF UKRAINIAN MILITARY FORMATIONS IN THE GERMAN ARMED FORCES AS A SOURCE FOR STUDYING THE DAILY LIVES OF SOLDIERS OF WORLD WAR II
Authors: Vovk O. V.
Published: October 2021

The article deals with how the memoirs highlight the peculiarities of everyday life of Ukrainian servicemen who were members of Ukrainian military formations in the German armed forces during the Second World War. Ukrainian combatants published a large number of memoirs, which highlighted the reasons that led them to combine their own destiny with service to a foreign country, described the social and construction conditions in which they found themselves, relations between soldiers, the attitude of Germans to Ukrainians, hopes for future Ukrainian revival. . These memoirs are an important source for studying the daily lives of soldiers during World War II. Although the issue of everyday life of Ukrainian soldiers was considered in the works of researchers, it is of secondary importance. Because of this, there is a problem of a more detailed study of the daily life of soldiers who found themselves in various formations of the German armed forces during World War II, and whose activities were not criminalized by the international community. Significant factual material on this issue provides an analysis of the memories of Ukrainian combatants. The publication provides a critical analysis of the memoirs of P. Hrytsak, M. Kalba, V. Ketsun, R. Kolisnyk, T. Krochak, R. Lazurko, K. Malyi, I. Nahaievskyi, E. Pobihushchyi and others. It was found that the memoirs cover in detail the domestic aspects of the service (military training, leisure, material support, cultural life, morale and mood of the soldiers), relations with the German personnel of the units. The authors’ memoirs contain numerous descriptions of the daily life of soldiers during military training, redeployment and participation in hostilities. Eyewitnesses described the soldiers’ equipment, the content of the instructors’ lectures and talks, the arrangement and plan of the camp, the relations between the Ukrainians and the relations with the Germans, and the peculiarities of the soldiers’ leisure. It is important to describe the transformation of the mood of the Ukrainian soldiers of the Division “Galicia”. These sentiments transformed from optimistic to a complete loss of confidence and growing dislike for German uniforms. Studies of this historical issue indicate that the authors of the memoirs describe the predominantly superior attitude of German personnel towards Ukrainians. It is investigated how the memoirs provide information about relations with the local population in the areas where the Ukrainian units were located. The publication highlights how the memoirs characterize the role of the church and priests in the life of Ukrainian units, which consisted not only in the religious and spiritual care of soldiers, but also in everyday life.
A method to compute detection range for electro optical transducers used for anti-ship missiles guidance
Authors: CLINCI CATALIN
Published: October 2021

In this paper we briefly present a method to compute detection range for electro optical transducers used for naval missiles guidance.
Modal Split of Inland Freight Transport. Study Case: Romania
Authors: Nistor Filip
Published: October 2021

Starting from the fact that over 80% of the global freight transport is using seas and oceans, it’s interesting to know how is splitting the inland freight transport on rail, road and inland waterways. Inland freight transport is dominated by road transport but attempts are being made, by various means, to increase the share of rail and inland waterway transport. The objectives proposed by EU for limiting greenhouse gas emissions require using of less polluting means of transport. The transformations in logistics chains cause by Industry 4.0 impose permanent adaptations of the transport modalities to the market requirements. The present paper proposes an analysis of the share of inland transport modes in the case of Romania and the influence of different factors for each mode of transport
Using regression theory to solve some problems regarding ship repairing and maintenance activities in shipyards
Authors: Emil Manea
Published: October 2021

The owners will always try to reduce the ships maintenance works timeframe clearly aimed at reducing the period during which the ship has no income. In turn, the shipyard also will try to reduce the timeframe for the maintenace works carried out on board of the drydocked ships and alongside berths, clearly aimed at revenue maximizing by contracting a larger number of ships for drydocking. The objective was to find a method (using regression theory) for the ships drydocking and/or berthed maintenance works carried out in the shiprepairs shipyards time frame that exploits the information held by the shipyard in their maintenance and repairs works portfolio performed for various customers over time.
Digital Flashcards in the EFL Classroom
Authors: Raluca Apostol-Mates
Published: October 2021

The starting point of our research has been the assumption that conversation at sea is vital. Broadly speaking, communication arises when there is a lack of information which needs to be filled between the speaker and the listener. The problem with using specialized language in order to achieve this goal has led to a need for alternative teaching approaches meant to facilitate the acquirement and usage of such an intricate lexical domain such as Maritime terminology. Mnemonic educational strategies have proved themselves as useful, beneficial tools for learners of technical English in general and maritime English in particular. Our study aims at highlighting a few aspects pertaining to this topic as well as providing a more practical approach for the ESP classroom.
A Review over AI Methods Developed for Maritime Awareness Systems
Authors: Alexandru Pohontu
Published: October 2021

Due to their operations against illegal activities, maritime threats or collision prevention analysis, maritime surveillance plays a vital role in maritime traffic security and safety management. Today's maritime surveillance and awareness systems can integrate multiple data sources like: coastal, HFSWR and SAR radars, AIS or satellite imagery; and this process produces massive amounts of data. That available data can be processed, with the use of Artificial Intelligence (AI) methods and algorithms, to automatically monitor the maritime traffic and its implications in safety, security, economy and environment. This paper's purpose is to briefly reveal current AI techniques that have been researched and deployed in the industry, and to seize the opportunity of implementing them.
Nonadiabatic nonlinear optics and quantum geometry — Application to the twisted Schwinger effect
Authors: Takayoshi Shintaro , Wu Jianda , Oka Takashi
Published: October 2021

We study the tunneling mechanism of nonlinear optical processes in
solids induced by strong coherent laser fields. The theory is based on
an extension of the Landau-Zener model with nonadiabatic geometric
effects. In addition to the rectification effect known previously, we
find two effects, namely perfect tunneling and counterdiabaticity at
fast sweep speed. We apply this theory to the twisted Schwinger effect,
i.e., nonadiabatic pair production of particles by rotating electric
fields, and find a nonperturbative generation mechanism of the
opto-valley polarization and photo-current in Dirac and Weyl
fermions.
PROSODIC STRESS IN THE THEORY OF RHYTHM BY HENRI MESHONNIK UNDER THE MAGNIFYING GLASS OF EXPERIMENTAL PHONETICS
Authors: BELAVINA Ekaterina M.
Published: October 2021

Henri Meschonnik’s legacy includes diversified, multidisciplinary, interdisciplinary research. The history and theory of literature, philosophy and linguistics underlie his methodology for studying rhythm. To analyze the text, Meshonnik uses the stress system, in particular, the prosodic stress that occurs on the first syllable of a word when its first consonant is repeated in a verse or in a prosaic sentence. The existence of prosodic stress, which is understood in this way, is ignored by phoneticians. The stress in the text is presented in the theory of Madden as a symbolic display of a clot of energy, since initially stress in speech concentrates muscular effort. The article makes an attempt to determine what is the current status of prosodic stress, an important element of A. Meshonnik’s analytical apparatus.
Stress has measurable acoustic parameters (intensity, pitch, duration), so an experiment was carried out (using a Praat speech analyzer). The stress on the first syllable in French phonetics is considered to be additional, depending on the individual implementation, however, Meshonnik, as well as his follower and co-author J. Desson, consider prosodic stress to be a linguistic (phonological) law. The article describes the stage of the experiment when native speakers (students of ENS Paris) were offered the phrase of Flaubert, commented by Madden and Desson in “Treatise on Rhythm”, and the same phrase, modified in two ways, to trace the stress in the absence of sound repetition. In the course of the experiment, most of the participants showed a slight increase in intensity when reading the original phrase, a decrease in intensity when reading a shortened phrase, and in some cases, the intensity increased when reading a phrase with a word modified to avoid repetitions.
Splice Junction Identification using Long Short-Term Memory Neural Networks
Authors: Regan Kevin , Saghafi Abolfazl , Li Zhijun
Published: October 2021

Background:

Splice junctions are the key to going from pre-messenger RNA to mature messenger RNA in many multi-exon genes due to alternative splicing. Since the percentage of multi-exon genes that undergo alternative splicing is very high, identifying splice junctions is an attractive research topic with important implications.

Objective:

The aim is to develop a deep learning model capable of identifying splice junctions in RNA sequences using 13,666 unique sequences of primate RNA.

Method:

A Long Short-Term Memory (LSTM) Neural Network model is developed that classifies a given sequence as EI (Exon-Intron splice), IE (Intron-Exon splice), or N (No splice). The model is trained with groups of trinucleotides and its performance is tested using validation and test data to prevent bias.

Results:

Model performance was measured using accuracy and f-score in test data. The finalized model achieved an average accuracy of 91.34% with an average f-score of 91.36% over 50 runs.

Conclusion:

Comparisons show a highly competitive model to recent Convolutional Neural Network structures. The proposed LSTM model achieves the highest accuracy and f-score among published alternative LSTM structures.
Lactoferrin as a Potent Natural Supplement Exhibiting a Synergistic Effect
with Drugs in Antimicrobial and Anticancer Therapies
Authors: Gajda-Morszewski Przemysław , Brindell Małgorzata
Published: October 2021

:

For many years, natural products have played a crucial role in drug discovery and drug
design as a source of active agents or as inspiration. Lactoferrin (Lf), a glycoprotein found in milk
and mammalian secretions, has been extensively studied in recent years, and numerous antimicrobial,
anti-inflammatory, and anticancer properties of Lf have been demonstrated in the literature.
The use of lactoferrin as a co-agent or supplement to enhance the beneficial effect of drugs, or to reduce
their side effects, arouses the interest of many researchers, especially since Lf is a well-studied,
biocompatible, cheap, and easily accessible protein. In this mini-review, we focus on the
elucidation of the role of Lf in antimicrobial or anticancer therapies, pointing to the possible mechanism
underlying the determined synergism between Lf and commonly used drugs.
Anatomía de la madera de especies de Forestiera (Oleaceae) en México
Authors: Ruiz-Valencia Jesús Alejandro , Vázquez Monserrat , Burgos-Hernández Mireya , Gutiérrez Jorge , Terrazas Teresa
Published: October 2021

Antecedentes y Objetivos: Uno de los enfoques más recientes para delimitar especies vegetales es el uso de caracteres anatómicos de la madera en representantes leñosos que ha sido poco explorado en taxones mexicanos. El género Forestiera (Oleaceae) es un ejemplo de esto, pues solo se ha descrito la madera de dos de las 12 especies distribuidas en México. Con el objetivo de contribuir al conocimiento de la anatomía de la madera del género, así como a la búsqueda de caracteres anatómicos que discriminen entre sus especies, en el presente estudio se describe la anatomía de la madera de ocho especies de Forestiera distribuidas en México con un enfoque sistemático.
Métodos: Se analizaron 42 muestras de madera de ocho especies, provenientes de tres individuos por especie en 14 sitios de colecta. El material se procesó con microtecnia convencional para obtener variables anatómicas cualitativas y cuantitativas. Estas fueron evaluadas con estadística multivariada para determinar cuáles son importantes para formar grupos de especies en Forestiera.
Resultados clave: Algunos atributos anatómicos reportados anteriormente coinciden con los observados en este trabajo. Sin embargo, hay diferencias como la porosidad semianular y la delimitación de marcas de crecimiento sin presencia de parénquima marginal. Los análisis formaron grupos de especies dados por el diámetro de vasos de la madera temprana, longitud de elementos de vaso y fibras, diámetro de las fibras, tipo de radios, abundancia del parénquima marginal y tipo de cristales en los radios. Con base en la anatomía de la madera, se propone una clave taxonómica para identificar las especies estudiadas.
Conclusiones: Mediante los análisis empleados se contribuye al conocimiento de la anatomía de la madera de Forestiera; además, se reconocen caracteres que permiten distinguir grupos de especies. Futuros estudios confirmarán su valor taxonómico.