bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparación de la seguridad al deslizamiento de seis presas españolas. Criterios de diseño empleados frente al estado del arte actual.
Authors: Alonso Pérez Julián , Romera Rodríguez Luis
Published: July 2021

Se ha desarrollado y aplicado un método simplificado para reevaluar de forma más precisa la seguridad al deslizamiento en seis presas de gravedad y contrafuertes en base a los resultados de modelos lineales numéricos, verificando su validez mediante análisis no lineales y medidas experimentales. Se han llevado a cabo sondeos con recuperación de testigo cercanos al tacón aguas arriba para inspeccionar posibles agrietamientos en las interfases hormigón-roca y se han instrumentado con extensómetros para analizar los datos de aperturas. Los resultados obtenidos, demuestran que los criterios de diseño utilizados en los años 50, en algunos casos no cubren el margen de incertidumbre esperado, respaldando así la necesidad de revisar las grandes presas españolas actualizando los análisis tal como rezan las Normas Técnicas de Seguridad de Presas que recientemente ha aprobado el Gobierno.
Collaborative Learning Community Facilitating Inclusive Learning Settings
Authors: Ikuta Shigeru , Takagaki Yu , Sone Reiko , Ozaki Keiko , Abe Shinya
Published: July 2021

One of the authors (Shigeru Ikuta) has organized a collaborative learning community with schoolteachers to provide reasonable accommodations for students with disabilities using newly developed multimedia-enabled dot codes. He created “Post-It-like” sticker icons on which dot codes were printed; each sticker icon could be linked with up to four multimedia mediums, in addition to up to four voices/sounds. Touching a dot code icon with a speaking-pen enables audios to be replayed and touching a dot code icon with a dot-code reader enables multimedia to be replayed. Four software packages to create self-made contents were developed by Gridmark Inc. The sticker icons, a speaking-pen and dot-code reader, and software packages are distributed to schoolteachers for free; they can now create original teaching materials for students in classes. The present newly developed software and tools are quite useful to support the students with various difficulties in inclusive learning settings.
CSR as a Stakeholder to the COVID-19 Pandemic
Authors: Bhardwaj Aashish , Gupta Anu , Kumar Surender
Published: July 2021

Corporates around the world have engaged themselves in a wide range of philanthropic and corporate social responsibility (CSR) initiatives to protect their employees, support communities, and maintain trust in society during the COVID-19 pandemic. This chapter highlights the CSR initiatives by 20 major companies during the COVID-19 pandemic. The contributions relate to technology solutions, support to education and healthcare, support to government initiatives, and support to own employees and customers, etc. Providing free tools for collaboration and the development of chatbots are some innovative solutions that have affected a large segment of the people. Along with this, traditional methods of support like eradication of hunger, healthcare, education, and disaster management have remained a focus for a number of corporates across the globe. The chapter analyses the prominent initiatives and their contribution to society during a pandemic and discusses their sustainability perspective.
Enhanced Innovation Process as a Key Driver of Bakery Performance
Authors: Jeje Kafigi , Naidoo Vannie , Verma Rahul
Published: July 2021

Small and medium-sized enterprises (SME) in the food sector play a pivotal role in contributing to the developing county's economy. In order to improve a small and medium-sized enterprises (SME), one key driver is innovation, and for innovation initiatives to grow and succeed, they depend largely on the leadership and the innovation capabilities of the firm. This chapter will shed more light on the impact of the enhanced innovation process on the performance of small and medium-sized enterprise (SME) bakeries. A qualitative study was conducted on 186 registered bakery owners/managers of bakeries. The results indicated that the relationship between enhanced innovation process and output level in small and medium-sized enterprises (SME) bakeries are significant. It has been revealed that the workforce's professional behaviour, the acquired competency through training, and the rewarding systems moderate the relationship between enhanced innovation process and output level in small and medium-sized enterprise (SME) bakeries.
Impact of Innovative Capital on the Global Performance of the European Union
Authors: Popescu Cristina Raluca Gh.
Published: July 2021

With the main objective of determining the essential factors that incorporate or enhance innovative capital, the present study, based, on the one hand, on the evaluation of the literature, allowed identifying ten potential factors and centered, on the other hand, on the analysis represented by the linear regression facilitated displaying the interdependencies between these factors and performance, thus determining the overall meaning and intensity of their contribution. In order to identify general and essential trends, to eliminate the cyclical influences of innovative capital, the present study was conducted on the basis of public and free access data contained by Eurostat, the transparency and accessibility of information being very important criteria in defining a simple and successful model, applicable for assessing the contribution of intellectual capital, in general, and its most dynamic component of innovative capital to increasing the performance of organizations.
Social Media as a Communication Channel
Authors: Yurder Yigit , Akdol Buket
Published: July 2021

In digital world, people spend most of their time on social media. Social media has gone beyond being just an online communication platform. It has become a channel that users prefer to other online platforms, such as websites, blogs, forums to get information about various businesses, events, and individuals. With Industry 4.0, all devices are connected to online platform, smart devices get more place in daily life. Instead of accessing information through individual applications, consumers prefer to obtain information from the company's social media pages and/or the company's internal and external customers' shared content. The purpose of the chapter is to indicate the importance of social media use, for organizations to interact effectively with all stakeholders, and to explain the benefits of social media usage of organizations in terms of different functions with examples from best cases and results of empirical researches.
Exploring the Effects of Social Media Use on Employee Performance
Authors: Shujaat Asbah , Rashid Ammar , Muzaffar Asif
Published: July 2021

This study provides some clarification and extends literature by investigating the effects of the use of social networking sites by organizational employees on job satisfaction, organizational commitment and employee job performance. A survey was conducted to empirically test the proposed research model consisting of latent constructs: social networking site use, organizational commitment, job satisfaction, and employee job performance. Data of this confirmatory study was collected from 279 employees of various organizations operating in Pakistan. The model was analyzed employing variance-based structure equation modeling. Statistical software was used to assess both measurement and structural models. Results indicate that social networking sites use is not directly associated with employee job performance but with the mediating effects of job satisfaction that is also nested with the mediating effect of organizational commitment. This study is expected to both substantiate existing theories of management, and provide some extensions to social support theory.
Behavioural Evidence Analysis
Authors: Shree Barkha , Dhaliwal Parneeta
Published: July 2021

Recent developments in digital forensics (DF) have emphasized that along with inspection of digital evidence, the study of behavioural clues based on behavioural evidence analysis (BEA) is vital for accurate and complete criminal investigation. This paper reviews the existing BEA approaches and process models and concludes the lack of standardisation in the BEA process. The research comprehends that existing BEA methodologies are restricted to specific characteristics of the forensic domain in question. To address these limitations, the paper proposes a standardised approach detailing the step-by-step implementation of BEA in the DF process. The proposed model presents a homogenous technique that can be practically applied to real-life cases. This standard BEA framework classifies digital evidence into categories to decipher associated offender characteristics. Unlike existing models, this new approach collects evidence from diverse sources and leaves no aspect unattended while probing criminal behavioural cues, thus facilitating its applicability across varied forensic domains.
Development of Entrepreneurship in Universities
Authors: Cervantes-Guzmán Jovanna Nathalie
Published: July 2021

It is necessary for university students to be trained with real cases so that they experience experiential learning, where they have a concrete experience and learn from it. Integrating training, education, and soft skills arm them with the necessary tools to develop an entrepreneurial intention. This will be done by training multidisciplinary work using business models adapted to teaching entrepreneurship. Thus, achieving avoids drifting talent trained in universities, which does not find a stimulus to knowledge to achieve the development of their venture. It should be provided from schoolwork that can lead to potential businesses, through the association of different university careers to generate and enhance multidisciplinary professional student-student relationships.
A Practical Assessment of Modern IT Project Complexity Management Tools
Authors: Morcov Stefan , Pintelon Liliane , Kusters Rob J.
Published: July 2021

Complexity is ubiquitous in modern engineering and project management. It is traditionally associated with failure. Also, complexity works! It delivers functionality, creativity, innovation. Complexity management contributes to the success of high-risk IT projects, helps better project understanding, allows for better prioritization and planning of resources. Managing negative complexity reduces project risk. Positive and appropriate complexity are catalysts for opportunities. This paper is a qualitative longitudinal study based on multiple industry project cases, consisting in the repeated evaluation of a set of complexity management tools. The tools were deployed in a classical process framework: plan, identify, analyze, plan responses, monitor, and control. The evaluated tools red-flag and measure complexity, analyze its sources and effects, and plan mitigation strategies. The study aims to provide project managers with methods for increasing project success rates and reducing failure in complex IT project environments.
FaD-CODS Fake News Detection on COVID-19 Using Description Logics and Semantic Reasoning
Authors: Goel Kartik , Gupta Charu , Rawal Ria , Agrawal Prateek , Madaan Vishu
Published: July 2021

COVID-19 has affected people in nearly 180 countries worldwide. This paper presents a novel and improved Semantic Web-based approach for implementing the disease pattern of COVID-19. Semantics gives meaning to words and defines the purpose of words in a sentence. Previous ontology approaches revolved around syntactic methods. In this paper, semantics gives due priority to understand the nature and meaning of the underlying text. The proposed approach, FaD-CODS, focuses on a specific application of fake news detection. The formal definition is given by depiction of knowledge patterns using semantic reasoning. The proposed approach based on fake news detection uses description logic for semantic reasoning. FaD-CODS will affect decision making in medicine and healthcare. Further, the state-of-the-art method performs best for semantic text incorporated in the model. FaD-CODS used a reasoning tool, RACER, to check the consistency of the collected study. Further, the reasoning tool performance is critically analyzed to determine the conflicts between a myth and fact.
Analyzing Linguistic Features for Classifying Why-Type Non-Factoid Questions
Authors: Breja Manvi , Jain Sanjay Kumar
Published: July 2021

Why-type non-factoid questions are complex and difficult to answer compared to factoid questions. A challenge in finding an accurate answer to a non-factoid question is to understand the intent of user as it differs with their knowledge and also the context of the question in which it is being asked. Predicting correct type of a question and its answer by a classification model is an important issue as it affects the subsequent processing of its answer. In this paper, a classification model is proposed which is trained by a combination of lexical, syntactic, and semantic features to classify open-domain why-type questions. Various supervised classifiers are trained on a featured dataset out of which support vector machine achieves the highest accuracy of 81% in determining question type and 76.8% in determining answer type which shows 14.6% improvement in predicting an answer type over a baseline why-type classifier with 62.2% accuracy.
Optimization of Green Synthesis Approach of Silver Nanoparticles Using Indonesian Wild Honey
Authors: Marsudi Maradhana Agung , Sari Farah Fitria , Wicaksono Pandu Mauliddin , Asmoro Adinda , Basuki Arif , Wibowo Arie
Published: July 2021

In this work, silver nanoparticles have been successfully synthesized using simple and environmentally friendly ‘green synthesis’ method using Indonesian wild honey as mediator. Particle count and size can be optimized by varying the silver nitrate precursor and honey concentration, with the help of sodium hydroxide as pH regulator. Based on X-ray diffraction (XRD) result, crystalline structure of Ag has been confirmed in sample with impurities from AgCl. Based on dynamic light scattering (DLS) and transmission electron microscopy (TEM) results, it was found that the smallest average particles size of AgNPs (117.5 nm from DLS and 11.1 nm from TEM) was obtained at sample with 5% w/v of honey and 0.5 mM of AgNO3.
Tool Wear Characteristics of TiCn/Al2O3 Coated Carbide Inserts while Turning Glass Fiber Reinforced Epoxy Resin under Cryogenic Cooling
Authors: Chanpariyavatevong Amarin , Boongsood Wanwanut
Published: July 2021

The main issue in machining glass fiber reinforced polymers is a rapid wearing of the cutting tool caused by the superior properties of the fiber reinforcement within the matrix. Cooling in machining processes reduces tool wear and extends tool life. Cryogenic cooling is an alternative method for effective, environmentally friendly, clean and safe cooling. This paper studied the tool wear characteristics of carbide inserts coated with TiCN and Al2O3 in turning glass fiber reinforced epoxy resin pipe. The cutting parameters were various, with cutting speed, feed rate, depth of cut and cutting conditions (without cooling and with cryogenic cooling). Not all cutting speeds that were cooled under cryogenics showed good outcomes. However, the experimental results suggest that using high cutting speed at 1800 rpm and high feed rate at 0.13 mm/rev, together with cryogenic cooling, can reduce the flank wear of the tool compared with no cooling.
Effects of Steam Heat and Dry Heat Sterilization on Thermal and Mechanical Properties of Nylon and Policarbonate in Fabrication with Fused Filament
Authors: Fuentes Jorge Mauricio , Unda Omar Flor , Ferrandiz Santiago , Suarez Franyelit
Published: July 2021

In this article presents evidence about performance of mechanical properties of polycarbonate and nylon materials, which are used in the additive manufacturing by deposition of molten material and that have been subjected to sterilization processes by moist heat at 121°C and dry heat at 140°C. This study provides useful information to consider the use of these materials in sanitary and sterile settings. Mechanical tests of tensile, flex, hardness, Izod impact, thermal tests in Differential Scanning Calorimetry DSC, Thermomechanical analysis TMA and Scanning Electron Microscopy SEM were performed. It is concluded that the mechanical and thermal properties have not been altered through the effect of temperature in sterilization processes.
Investigation on Stress and Strain of Ni-Based Single Crystal Super-Alloy Specimen with Single Hole Based on Abacus
Authors: Xue Xiang Zhen , Wen Zhi Xun , Li Wen Xian
Published: July 2021

The Miss stress, Max.principal strain and Magnitude displacement have important influence on the fatigue life of the Ni-based single crystal super-alloy turbine blades. This work investigated The Miss stress, Max.principal strain and Magnitude displacement of Ni-based single crystal super-alloy specimen with single hole along dangerous path under different working conditions by Abacus. The results show that the initial crack length and loading stresses are larger, the crack growth on the specimen is faster, and then, the fatigue life is the shorter. Moreover, for the different stress ratios, smaller stress ratio can lead to lower fatigue life. The result is significant to design turbine of Ni-based single crystal super-alloy of high accuracy, high reliability and high strength.
Defects Reduction in Spheroidal Graphite Iron Casting Process of a Jackscrew Manufacturer
Authors: Muangyai Supachart , Chutima Parames
Published: July 2021

This research focused on defects reduction in spheroidal graphite iron casting process of a jackscrew manufacturer in which graphite nodularity was lower than a given specification (75%). This situation could lead to serious issues and accident to end-users. The Six Sigma approach of DMAIC was employed to identify and eliminate the problems. The result obtained after implementing the Six Sigma showed that the process capability was improved from-0.47 to 2.04, and the average per cent graphite nodularity was increased significantly from 61.49% to 86.43%.
Effect of Ultraviolet Aging on Composition, Structure and Properties of Asphalt
Authors: Li Yong Gui , Zhou Xiang
Published: July 2021

Asphalt aging is a pivotal factor affecting the service performance of asphalt pavement. Previous studies often ignored the influence of ultraviolet radiation on asphalt aging. Coincidentally, there is no standard test method of photooxidation aging that can be applied to guide engineering practice. In this paper, the influence of ultraviolet aging on the composition, structure and properties of asphalt was studied by adopting Bert four-component method, Fourier transform infrared spectroscopy aned dynamic shear rheometer. Bert four-component method elaborates that the content of asphaltene increases and the content of aromatic component decreases after UV aging. Fourier transform infrared spectroscopy indicates that there are obvious peaks of carbonyl and sulfoxide groups after aging, the penetration of asphalt decreases while the softening point and viscosity increase. Moreover, the composite modulus of asphalt increases obviously at low temperature, but has little effect on the composite modulus at high temperature.
Fixed-Bed Adsorption Column Studies for the Removal of Methyl Orange from Water Using Polyethyleneimine-Graphene Oxide Polymer Nanocomposite Beads
Authors: Nolasco Jirah Emmanuel T. , Alvarillo Camille Margaret S. , Chua Joshua L. , Gonzales Ysabel Marie C. , Perez Jem Valerie D.
Published: July 2021

Continuous fixed-bed column studies were performed using nanocomposite beads made up of chitosan, polyethyleneimine, and graphene oxide as adsorbents for the removal of methyl orange (MO) in water. The effects of different operating parameters such as initial MO concentration (5, 10, and 15 ppm), bed height (10, 17.5, and 25 cm), and flow rate (27, 43, and 58 mL/min) were investigated using an upward-flow fixed-bed column set-up. The breakthrough curves generated were fitted with Adams-Bohart, Thomas, Yoon-Nelson, and Yan et al. models. The results showed that Yan et al. model agreed best with the breakthrough curves having an R2 as high as 0.9917. Lastly, design parameters for a large-scale adsorption column were determined via scale-up approach using the parameters obtained from column runs.
Fe/S Co-Doped Titanium Dioxide Nanotubes: Optimization of the Photoelectrocatalytic Degradation Kinetics of Phenol Red
Authors: Lopez Edgar Clyde R. , Saputil Nicole Elyse B. , Loza Lance A. , Camiguing Fiona Fritz G. , Mopon Jr. Marlon L. , Perez Jem Valerie D.
Published: July 2021

Photoelectrocatalysis has emerged as a promising technology to degrade recalcitrant pollutants such as textile dyes in wastewater completely. Titanium dioxide is typically used as a photocatalyst, but its wide bandgap constrains its use to the use of ultraviolet light. To extend its use to the visible-light region, we doped titanium dioxide nanotubes with iron and sulfur. We used them as a photoelectrode for the photoelectrocatalytic degradation of a model pollutant – phenol red. Response surface methodology using a Box-Behnken design of experiments was used to investigate the effects of initial dye concentration, applied potential, and dopant loading on phenol red degradation kinetics. Statistical analysis showed that our reduced cubic model adequately correlates these parameters. The fastest dye degradation rate was achieved at the optimized conditions: initial phenol red concentration = 5.0326 mg L-1, applied voltage = 29.9686 V, and dopant loading = 1.2244 wt.%. Complete degradation of phenol red may be achieved after 11.77 hours of treatment under the optimized conditions in a batch reactor. Our model's robustness enables it to be used for process modeling and a basis for designing scaled-up photoelectrocatalytic reactors.
Highly Active Fischer-Tropsch Synthesis Fe-BDC MOF-Derived Catalyst Prepared by Modified Solvothermal Method
Authors: Rashed Ahmed Elsayed , Essam Kamal , El Kady Marwa F. , Yoshihisa Matsushita , El-Moneim Ahmed Abd , Nasser AL-Hassan Mohammed
Published: July 2021

Fe-MIL-88B was prepared by a method that utilizes ferric nitrate and terephthalic acid (TPA or H2BDC) as precursors. The catalyst was characterized by TEM, SEM, FTIR, XRD, BET, and TGA. The pyrolyzed MOF (Fe-MIL-88B/C) was then tested for FTS at 300 psi, 300/340°C and H2/CO=1 after reduction under flow of hydrogen at 400°C for 4 hours. GC product results show promising FTS performance and stability compared to previously reported Fe-MOF derived catalysts with CO conversion of 96.90% at 340°C for 40 hours and 97.45% at 300°C for 26 hours.
The Effect of Sodium Hydroxide Concentration on the Structure of Iron Oxides@Bacterial Cellulose and their Catalytic Activity for Methylene Blue Degradation in Solution
Authors: Marsudi Maradhana Agung , Hawari Fakhri Arsyi , Parmita Ade Wahyu Y.P. , Triadhi Untung , Ardy Husaini , Wibowo Arie
Published: July 2021

Heterogeneous fenton , although offering promises for large scale wastewater treatment, is still hindered in its practicality due to its modest catalytic activity. The usage of catalyst supportas been demonstrated previously toecrease the overall particle size to improve its catalytic performance. In this demonstration, fenton catalysts were prepared using the sol-gel method and bacterial cellulose (BC) as catalyst support, with varying sodium hydroxide (NaOH) concentrations (0.01; 0.1 and 1 M). NaCl impurities' presence was successfully eliminated by reducing NaOH concentration relative to the previous 4 M concentration. Lower NaOH concentration leads to a more favorable condition for the formation of smaller non-agglomerated particles and magnetite (Fe3O4) as its main crystalline phase. It was found that the best performing catalyst was produced using 1 M NaOH and was able to degrade Methylene blue solution up to 53.8% remaining dye concentration within two hours.
Challenges and Opportunities for the Applications of Unconventional Superconductors
Authors: Ye Cheng Yu , Wang Zhao Ye
Published: July 2021

Since the discovery of superconductors, research has shifted from simple metals to alloys and further to complex compounds. As the record of critical temperature gradually increases, more opportunities and challenges have emerged. The Bardeen-Cooper-Schrieffer theory failed to explain certain observations of unconventional superconductors. However, breakthroughs have been made on the new understanding of unconventional superconductors. This article will introduce various challenges to and opportunities for the application of unconventional superconductors, including the high-temperature superconducting fault-current limiter and the superconducting energy-storage system.
The Structure and Properties of Dispersed Aluminium Composite Compounds Made by Welding Friction with Mixing
Authors: Feofanov A.N. , Ovchinnikov Viktor Vasilevich , Gubin A.M.
Published: July 2021

The use of friction welding with mixing allows to obtain non-defectal compounds of both alloy AL25 and dispersed particles composite aluminum materials. It was found that in addition to changes in the grain structure of the α-Al solid solution, there are changes in the process of the release of particles of intermetallide phases, which can be traced in the morphology, medium size and chemical composition of particles of intermetallide phases of different natures. The change in the morphology of secondary phase particles is due to the difference in thermo mechanical influence in different areas of the formation of the compound when welding friction with mixing.
Comparative High-Field Magnetization Study of (Sm,Er)2Fe17 and Er2Fe17 Compounds and their Nitrides
Authors: Ivanov Lev Aleksandrovich , Paukov Michael , Tereshina Irina , Veselova Svetlana , Akimova Olga V. , Verbetsky Victor , Gorbunov Denis Ivanovich
Published: July 2021

Magnetic properties of the R2Fe17 compounds are sensitive to the atomic substitutions and interstitial absorption of nitrogen. In our work, both were combined and their effect on the magnetization behavior of Er2Fe17 compound in magnetic fields up to 58 T was studied. Er2Fe17N2, Sm1.2Er0.8Fe17N2 and Sm1.8Er0.2Fe17N2.1 nitrides were prepared. Magnetization measurements were carried out, mainly on powder samples (excluding Er2Fe17 single crystal). Nanopowders of Sm1.2Er0.8Fe17N2 were obtained by mechanical grinding. The grinding time was varied from 0 to 60 minutes. The strength of the inter-sublattice coupling in samples is estimated by analyzing high-field magnetization data.
Improvement of Thermal Conductivity for Carbon Fabric Composites Base on the Fabric Structure
Authors: Kyaw Phone Thant , Maung Pyae Phyo , Malysheva Galina V.
Published: July 2021

This paper presents the development of methods for improving the thermal conductivity of fiber reinforcing materials based on the fabric structures. The thermal analysis of fabric structure in thermal load calculation is performed by Fourier’s Law of Thermal Conduction and Steady-State Thermal calculation in Siemens NX. This study leads to the development of thermal conductivity in manufacturing technology of fiber reinforcing materials. Keywords: Thermal conductivity, fabric structure, polymer composite materials
The Patterns of Phase Composition and Properties of High-Calcium Low-Density Ceramics Formation Based on Argillous Raw Materials of Various Chemical and Mineralogical Composition
Authors: Yatsenko Natalia , Yatsenko Aleksandr I. , Vil'bitskaya Natalia A. , Sazonova Olga I. , Savanchuk Rimma V.
Published: July 2021

The post-sintering properties of walling high-calcium ceramics based on clay-containing raw materials in low-temperature roasting depend on the chemical-mineralogical composition of clay with different contents of iron, calcium-containing and alkaline oxides that contribute to the formation of new crystalline phases, which provide for the production of low-density ceramic material with high-strength properties.
Creation of Basalt Plastics with Different Types of Hybrid Matrices
Authors: Kosenko Ekaterina , Baurova Natalya , Zorin Vladimir
Published: July 2021

Basalt plastic, thanks to its complex of valuable operational properties, has a potential variety of applications. the article describes the technology of production of basalt plastics with various types of hybrid matrices, one of the components of which is cured in the molding process, and the second-like a binder in natural materials, retains its viscoelastic state. The viscoelastic component makes it possible to increase the deformation properties in the zones of their location, preventing cracking under increased loads. As a result of the conducted mechanical tensile tests, the average values of absolute breaking forces, tensile strength and elongation during fracture of basalt plastic samples with different types of hybrid matrices were obtained. The addition of viscoelastic components (such as technical wax, anaerobic, and organosilicon polymer materials) to the basalt plastic matrix allows to increase the elongation at fracture by 2...5%. Anaerobic polymer material in the basalt plastic matrix allows to increase the tensile strength of the composite material, as well as significantly reduce the dispersion of the measured values. This provides an effective prediction of the operational properties of the structural material in the design of products. On the basis of microanalysis of the structure of basalt plastics with different types of hybrid matrices, an explanation of the causes of changes in the mechanical properties of the resulting composite materials is given.
New Technologies for Producing Multifunctional Reinforced Carbon Plastics
Authors: Neluyb Vladimir A. , Malysheva Galina V. , Komarov Ivan A.
Published: July 2021

In this article we investigated properties of elementary carbon fibers after their activation and subsequent deposition of thin layers of metal coatings on their surface. For deposition we used copper, titanium and stainless steel. We investigated influence of various technologies of preliminary processing of the fiber surface on the value of the adhesion strength of the metal coating to the carbon tape and on the mechanical properties of elementary fibers. We established that the strength of carbon plastics at interlayer shear increases by 10-30% when using carbon tapes and fabrics with a metal coating.
Specific of the Recrystallization Driving Force Calculation on the early Stages of Thermomechanical Treatment of Aluminum Alloys
Authors: Aryshenskii Evgeniy V. , Hirsch Jürgen , Beglov Erkin D. , Konovalov Sergey , Kargin Vladimir R.
Published: July 2021

The article investigates the effect of the strain rate on the driving force of recrystallization during hot working of the as-cast structure. For the study, we applied previously obtained experimental data of recrystallization kinetics during this stage of thermomechanical treatment. In addition, hot laboratory rolling, followed by saltpeter bath soaking, were performed in order to obtain supplemental data on grain structure size and orientations. Grain structure size was examined by optical microscopy, and its orientation was examined by X-ray texture analysis. The studies demonstrated, that overestimated recrystallization driving force not only results in erroneous kinetics estimation, but also gives excessive number of recrystallization centers and undersized grain structure. Besides, unaccounted effect of recrystallization driving force on grain size leads to distorted predictions of texture composition. In order to avoid this, it was recommended to apply an special exponential accumulated strain dependent coefficient.
Science-Based Technologies in the Manufacture Liquid Rocket Engines Filter Element Channels
Authors: Ryazantsev Alexander , Shirokozhukhova Anna , Shipilova Olga
Published: July 2021

The article discusses the technologies used in the manufacture of liquid rocket engines filter elements. The analysis of the most widely used methods in the aerospace industry for obtaining grooves and holes in metal filters is carried out, as well as progressive methods for their production are proposed. Special means of technological equipment for the fine filter elements manufacture using electroerosion treatment have been developed.
Forecasting of the Possibility of Fragile Destruction Top of Cutting Blade of a Thread Forming Tool
Authors: Selemenev Michael F. , Tarapanov Alexander S. , Frolenkova Larisa Yu. , Novikov Alexander D. , Prasolov Egor A.
Published: July 2021

A model of the magnitude of the stresses of the tip of the cutting blades of a thread-forming tool based on the theory of a homogeneous body is proposed. A model of second-order materials is considered. A description of the stress state is given using two stress tensors independent of each other.
Application of an Ultra-Compact Eddy-Current Transducer for Investigation of Defects in Welded Joints of High-Strength Steel
Authors: Malikov Vladimir N. , Ishkov Alexey V. , Nikonov Leonid
Published: July 2021

This article discusses the results of work on the creation of a flaw detection unit, which is focused on the study of high-strength steels. Welded joints of transformer tanks, which are made of steel grade 08G2B, were selected as the object of research. We chose this grade because of the ultra-low carbon content of this material. This opens up opportunities for the application of eddy current nondestructive testing methods. For practical measurements, a scanning device was designed and optimized. It includes a converter that uses the principles of eddy currents and includes three coils assembled on a ferrite core, grade 80NMZ. The device was tested on samples with model continuity defects (cracks and holes). Also, within the framework of the publication, modeling of corrosion defects in welded joints was carried out.
Optimization of Temperature Regimes of the Hotend for Devices of Additive Manufacturing
Authors: Sinev Andrey Y. , Panasenko Roman A. , Petrenko Valeria V. , Berestov Aleksandr Vasilievich , Bozhko Yuri V.
Published: July 2021

In this work, the authors tried to solve a typical problem of inexpensive 3D printers using FDM technology: material clogging of the hotend. To cope with the problem, it is necessary to solve the problem of optimization the temperature regimes of the hotend. For this, the temperature fields of the heating device were simulated taking into account the physical properties of the printing materials. Modeling was carried out using the ANSYS software package, the verification of theoretical calculations was carried out in a full-scale experiment. The data obtained was used to upgrade the 3D printer hotend.
Structure and Properties of a Local Diffusion Discrete Coating Applied to High Speed Steel
Authors: Chekalova Elena A. , Zhuravlev Andrey V.
Published: July 2021

Investigations of metallographic and mechanical properties of local diffusion discrete oxide coating on high-speed steel Р6М5 have been carried out. It was found that the technology of discrete oxidation makes it possible to increase the hardness by 31% in relation to the uncoated material, and the wear resistance of the cutting tool with oxidation is 1.5-3 times higher than that of the tool hardened by the standard ion-plasma technology.
Stress Simulation of the Structure of a Stretch Die Made by Fused Deposition Modeling
Authors: Koshkina Anastasia O. , Karpukhin Evgeny G. , Morozov Alexander V. , Abramov Alexander E.
Published: July 2021

The paper is devoted to the assessment of the possibility to use a new design of a stretch die made of plastics used for fused deposition modeling (FDM) 3 D printing. Studies were conducted to assess the stress-strain state of a stretch die, from the normal pressure of a deforming sheet blank in a NASTRAN solver, using the finite element method. The convergence assessment of the simulation results was carried out for different quantities and corresponding sizes of finite elements. The optimal thicknesses of the hollow structure of the stretch die were determined by step-by-step calculations of its stress-strain state for acrylonitrile butadiene styrene (ABS) and polyethylene terephthalate glycol (PETG). On the basis of the conducted studies, a general algorithm was developed for the structural design of stretch dies made of plastics used for fused deposition modeling (FDM) printing.
Influence of Mechanical Activation and Mechanical Alloying on the Structure, Phase State of the Fe-Ni-Co-Al-Nb Powder Composition and on High-Entropy Coatings Based on it
Authors: Blednova Zhesfina , Balaev Etibar Yusif O. , Yurkova Anna Pavlovna
Published: July 2021

The article presents the assessment study of mechanical activation and mechanical alloying effect on the structure, phase state of the powder composition and of the coating based on it. The duration of mechanical activation was varied as follows: 1 h, 2 h, 4 h, 8 h, 16 h, 32 h. It is shown that in order to from a high-entropy FeNiCoAlNb alloy on the workpiece surface the duration of mechanical activation must be at least 4 hours. We described the mechanism of mechanical alloying and ways of accelerating this process.
Features of Obtaining Multicomponent Magnetron Targets for the Formation of Non-Porous Transformation-Hardenable Coatings of a Given Composition
Authors: Plomodyalo Roman , Blednova Zhesfina , Dmitrenko Dmitriy
Published: July 2021

The technological process of thin-film sputtering significantly depends on the quality of the target for magnetron sputtering. This paper presents the features of obtaining the multicomponent magnetron target for the formation of non-porous transformation-hardenable coatings by the method of impact electric pulse consolidation. Special considerartion is given to the blend preparation and technological parameters of compaction. Blend powder consolidation under impact electric pulse compaction at different speeds of the striker has been investigated. At high speeds of the drop-hammer striker, the time parameters of the dynamic impact and electric pulse heating of the powder billet are shown to superpose, which leads to the final consolidation of the ceramic blend of the target for magnetron sputtering. The use of the technology of impact electric pulse compaction has made it possible to obtain multicomponent magnetron targets for formation of non-porous transformation-hardenable coatings of a given composition.
Influence of the Structural State of Titanium Alloy on the Depth of Penetration of Ions during Implantation
Authors: Ovchinnikov Viktor Vasilevich , Yakutina Svetlana Viktorovna , Kurbatova Irina Aleksandrovna , Luk'yanenko Elena Vladimirovna , Uchevatkina Nadezda
Published: July 2021

The article presents the results of the influence of the structural state of titanium alloys VT1-0 (α-alloy), VT20 (pseudo-α-alloy), VT6 (α + β) -alloy of the martensitic class) and VT15 (pseudo-β-alloy) on the penetration depth ions of nitrogen, aluminum, copper and the cathode of the alloy 50% Cu – 50% Fe. It is shown that the structural class of titanium alloys selected for the study, when exposed to ion implantation by both gases and metals, does not significantly affect the depth of their penetration.
Investigation of Residual Stresses during Processing of GTE Blades with Microbeads
Authors: Nosov Nikolay V. , Kurguzov Yuri I. , Lyushnya Dmitry A.
Published: July 2021

A method for determining the residual stress through the deformation of a witness sample during pneumatic blasting of gas turbine engine parts with microbeads is proposed. During the study, the processing modes and the diameter of the microbeads were changed. It is shown that with an increase in the diameter of the micro-ball from 0.3 mm to 0.7 mm, the deformation of the samples increased by 2 times, and with an increase in the speed of their movement from 70 m/s to 90 m/s by 50 %. The mechanism of formation of residual stresses and deformations of the treated surface of the witness sample is proposed.
Modeling of the Contact Interaction of the Tool Indenter with the Part Surface when Processing by Surface Plastic Deformation Methods
Authors: Fyodorov Vladimir P. , Nagorkin Maxim N. , Kheifetz Mikhail L. , Polsky Evgeny A.
Published: July 2021

There are results of studying the parameters of the indenter contact interaction with the surface when processing cylindrical parts made of 45 steel of different hardness by surface plastic deformation (SPD) methods with single-indenter elastic tools (diamond burnishing, ball burnishing). There were considered such characteristics as the resistance force when the indenter starts and in the steady state of SDP, the range of force fluctuations during processing, friction factor when the indenter starts and in the steady state, as well as some derivative coefficients. Adequate physical-statistical models for the quantitative estimation of the contact interaction parameters from SPD processing factors are obtained.
Development of Compositions of New Enamel Coatings with Various Operational and Decorative Properties to Protect Steel Architectural and Construction Panels
Authors: Ryabova Anna V. , Fanda A.Yu. , Yatsenko Elena A. , Lee Ming Gin
Published: July 2021

Metal enameling is widely used in construction, which differs enameled products from other building materials: the ability to obtain a variety of colors and surfaces; resistance of the surface under the influence of the atmosphere and sunlight; high corrosion resistance; light weight, lightness and quick installation; fire resistance; ease of cleaning; the possibility of mechanizing the manufacture of parts in serial production. The authors of the article have developed the compositions of enamel coatings and investigated their aesthetic and consumer and technical and operational properties. Also, three compositions of new enamel coatings for architectural and construction panels have been developed and enamel coatings of various colors, including pastel colors, have been obtained on their basis.
Reducing the Emission Activity of Vanadium from Building Materials
Authors: Pugin Konstantin G.
Published: July 2021

The article presents a study of the possibility of controlling the emission activity of heavy metals from building materials and structures. It has been established that the most active emission processes from building materials obtained using industrial wastes placed in aqueous media occur in the first five days in a neutral medium, and in the first ten days in an acidic medium. After that, the concentration of heavy metals in the aquatic environment begins to decrease. The results obtained on particular examples made it possible to establish dependencies that determine the intensity of emission processes under various conditions of contact between building materials and an aqueous medium. These dependencies are of a general nature and can be used to predict and control the formation of anthropogenic load. It is shown that the control of emission processes from building structures is possible by forming the structure of the material in the direction of increasing its hydrophobicity, density, and the content of alkaline compounds.
Investigation of the Peculiarities of Deformation and Fracture of Metals Obtained on the Basis of 3D Printing with Registration of an Acoustic Emission Signal
Authors: Anosov Maksim S. , Kabaldin Yury G. , Shatagin Dmitrii A. , Ryabov Dmitry A. , Kolchin Pavel
Published: July 2021

The paper investigates the features of deformation and fracture of steels obtained using the technology of 3D printing by electric arc surfacing based on the registration of the acoustic emission signal. With a decrease in the test temperature of 07Cr25Ni13 steel, a decrease in the work expended in stretching the specimen is observed, both at the stage of elastic deformation and at the stage of strain hardening. It was found that the most informative characteristic parameters of the AE signal include: the pulse count rate N, the total count NΣ, and the AE signal entropy. With a decrease in the test temperature, there is a significant increase in the intensity of the AE signal, the total number of pulses at all stages of deformation and destruction of steel. The obtained regularities of changes in the characteristic parameters of the AE signal can be used as diagnostic features, both in assessing the stage of deformation and destruction of the material, and the structural state of the material. Fractographic studies have shown a significant decrease in the tough component of 08Mn2Si steel with a decrease in the test temperature. The fracture mechanisms of 07Cr25Ni13 steel change insignificantly with decreasing temperature, however, a significant decrease in the ductility of the metal is observed, as evidenced by a decrease in the size of ductile fracture cups.
Optimization of Compositions and Hardening Conditions of Vibropress Concretes Based on Steel-Making Slag
Authors: Romanenko Igor , Fadin Alexey
Published: July 2021

The purpose of the study is to study the possibility of using secondary resources of metallurgical production, namely: steel-making slag and carbon dioxide in the production of vibropress products for construction purposes. The tests were carried out with the complete replacement of the coarse aggregate in the concrete mixture with steelmaking slag and varying the hardening processes. The optimal condition for strength gain is hardening in carbon dioxide at an increased pressure of 0,2 MPa.
The Structure and Properties of Asphalt Concrete on the Basis of Waste Foundry Sand
Authors: Pugin Konstantin G.
Published: July 2021

The features of the use of waste foundry sand to obtain secondary products are presented. The properties of the surface of mineral particles of waste molding sand are described. It is shown that on the surface of the particles there is a porous layer capable of increasing the adhesion forces of mineral particles with bitumen in the production of asphalt concrete. It has been established that the modified surface of the waste foundry sand contains up to 40% carbon, which provides an increase in the adhesion force between the mineral particles of the waste foundry sand and bitumen. It has been experimentally proven that the use of waste foundry sand in the composition of asphalt concrete can improve its physical and mechanical properties.
Kinematic Error Modeling of Delta 3D Printer
Authors: Kochetkov Andrey V. , Ivanova T.N. , Seliverstova Ludmila V. , Zakharov Oleg V.
Published: July 2021

The development of additive manufacturing requires the improvement of 3D printers to increase accuracy and productivity. Delta kinematics 3D printers have advantages over traditional sequential kinematics 3D printers. The main advantage is the high travel speed due to the parallel movement of the platform from three pairs of arms. Another advantage is the relatively low cost due to the small number of structural components. However, delta 3D printers have received limited use. The main reason is the low positioning accuracy of the end effector. Errors in the manufacture and assembly of components of a parallel drive mechanism add up geometrically and cause an error in the position of the end effector. These formulas can be applied to a 3D printer as well. However, well-known studies consider deterministic models. Therefore, the analysis is performed for limiting size errors. The purpose of this article is to simulate the effect of statistical errors in displacements and arm lengths on the positioning errors of a platform with the end effector. The article effectively complements the field of error analysis research and provides theoretical advice on error compensation for delta 3D printer.