bluuebunny/crossref_metadata_2025_split huggingface dataset:
Express calibration method for a mathematical model of interaction between the underground pipeline and the surrounding frozen ground
Authors: Гунар Алексей Юрьевич , Хилимонюк Ванда Здиславовна , Хрусталев Лев Николаевич , Пелих Эдуард Александрович , Коротков Алексей Александрович 
Published: June 2021

Вопрос повышения точности прогнозных расчетов при тепловом моделировании взаимодействия инженерных сооружений и вмещающих их многолетнемерзлых грунтов остается актуальным несмотря на то, что выбор программных продуктов, позволяющих проводить соответствующие расчеты, сегодня крайне велик. Точность прогнозного расчета определяется прежде всего исходными данными, закладываемыми в математическую модель. В этой связи первоочередной задачей является подбор адекватного набора исходных данных или калибровка математической модели. Авторами разработан экспресс-метод калибровки математической модели взаимодействия подземного трубопровода с многолетнемерзлым грунтом, позволяющий осуществлять калибровку, в том числе при отсутствии специальных наблюдений в системе «трубопровод - окружающая среда». В основу экспресс-метода положено решение обратной задачи Стефана методом эквивалентной температуры, сокращение количества исходных данных за счет замены многочисленных климатических параметров их интегральной характеристикой, а также использование аналитического математического аппарата модели вместо численного. Описанный в статье алгоритм может быть реализован несложной компьютерной программой, что позволит осуществлять многошаговый процесс калибровки в автоматическом режиме за считанные минуты.
The issue of improving the accuracy of predictive calculations in the thermal modeling of the interaction between engineering structures and the surrounding permanently frozen grounds remains relevant, despite the fact that the choice of software products that allow the relevant calculations today is extremely wide. The accuracy of the predictive calculation is determined primarily by the initial data inputted in the mathematical model. In this regard, the primary task is to select a suitable set of initial data or to calibrate the mathematical model. The authors have developed an express calibration method for a mathematical model of interaction between the underground pipeline and the permanently frozen ground, which allows carrying out calibration, including in the absence of special observations at the site in the "pipeline - environment" system. The express method is based on the solution of the inverse Stefan’s problem by the equivalent temperature method, reducing the amount of initial data by replacing numerous climatic parameters with their integral characteristic, and using the analytical mathematical apparatus of the model instead of the numerical one. The algorithm described in the article can be implemented by a simple computer program, which will allows the multi-step calibration process in automatic mode within minutes.
Improvement of the methodology assessment of reliability heat supply systems at the facilities of main pipelines
Authors: Ильина Марина Николаевна , Ларюшкин Дмитрий Васильевич 
Published: June 2021

Источником информации о техническом состоянии трубопроводов тепловых сетей объектов магистральных нефтепроводов ПАО «Транснефть» являются результаты их обслуживания и ремонта, технического освидетельствования, гидравлических испытаний и т. д. На основании этих данных проводятся расчеты показателей надежности, по итогам анализа которых осуществляется планирование дальнейшего технического обслуживания и ремонта. Однако при оценке надежности систем теплоснабжения необходимо учитывать не только срок эксплуатации и величину амортизационного износа, но и реальное состояние в конкретных условиях функционирования. Учесть многообразие факторов, которые влияют на работоспособность трубопроводов системы теплоснабжения, и тем самым повысить точность расчетов при оценке их остаточного ресурса позволяет применение кластерного анализа в дополнение к используемой методике оценки надежности тепловых сетей. В рамках настоящей работы оценка надежности объектов АО «Связьтранснефть» с применением кластерного анализа проведена на примере равнозначных участков тепловых сетей двух узлов связи, расположенных в Краснодарском крае и Республике Саха (Якутия).
Currently, information about technical condition of pipelines of heat supply systems at the facilities of the main oil pipelines of PJSC Transneft is formed based on the results of maintenance and repair, technical inspection, hydraulic tests, etc. Upon these data, calculations of reliability indicators of heat networks are carried out, based on the analysis of calculations further maintenance and repairs are planned. However, when assessing the reliability of heat supply systems, it is necessary to take into account not only the service life and the amount of depreciation wear of heat network elements, but also their real state in specific operating conditions. The use of cluster analysis in addition to the currently used method of heat network reliability assessment allows us to take into account the variety of factors that affect the operability of pipelines of the heat supply system, and thereby increase the accuracy of calculations when assessing their residual resource. Within the framework of this work, the reliability assessment of Svyaztransneft JSC facilities using cluster analysis was carried out on the example of equivalent sections of heat networks of two communication nodes located in the Krasnodar Territory and the Republic of Sakha (Yakutia).
Penilaian Kesehatan Bank (Studi Pada PT. Bank Muamalat Indonesia, Tbk. Tahun 2016- 2019)
Authors: Permata Citra Puspa 
Published: June 2021

This study aims to determine the financial health of PT. Bank Muamalat Indonesia, Tbk from four aspects in RGEC which is Risk Profile, Good Corporate Governance, Earnings, and Capital. This research is a descriptive study with a quantitative approach. The main data of this study comes from the Annual Report of PT. Bank Muamalat Indonesia, Tbk. from 2016 to 2019, the so-called secondary data were analyzed using the RGEC method. The results showed that in the period 2016-2019, the risk profile aspect of PT. Bank Muamalat Indonesia with the NPF and FDR Indicator on average is in a healthy financial condition, but the CR indicator showed unhealthy financial conditions. The GCG aspect using self-assessment showed a fairly healthy financial condition, the earnings aspect. with NOM, ROA and average ROE showed unhealthy financial conditions, as well as the capital aspect with average CAR and PR ratios is in very healthy financial conditions.
Relato de experiência de ensino de álgebra nos anos finais do ensino fundamental com atividades de cooperação
Authors: Pinheiro Bruno Reuber Maia 
Published: June 2021

Essa pesquisa aborda o ensino e aprendizagem da álgebra sob a perspectiva de um relato de experiência com atividades de cooperação nas turmas do 8º ano de uma escola pública no município de Quixadá-CE. Tem como objetivo contribuir na atuação docente com uma metodologia do ensino de álgebra através da sua aplicação, resultados e impactos. A pesquisa também traz a concepção de currículo em relação à álgebra, os desafios do ofício considerando o contexto escolar e sala de aula. A metodologia de ensino utilizada nesse trabalho é baseada na Aprendizagem Cooperativa que incide na aprendizagem a partir de trocas de experiências entre alunos e professor, em grupos, com discussões. A técnica de grupos cooperativos inclui a interdependência positiva, interação cara a cara entre os estudantes, responsabilidade individual e utilização de habilidades interpessoais e grupais. A atividade descrita é semelhante ao Team Assisted Individuation, pois combina atividade cooperativa com a instrução individualizada. A aplicação é motivada após se refletir sobre as dificuldades nas aulas, tanto pela dificuldade de interação quanto ao pensamento algébrico, mais especificamente em usar equações do primeiro grau para resolver situações-problema. O objetivo da atividade é que todos atinjam a habilidade para interpretar e resolver os problemas considerados difíceis. A estratégia coloca os alunos na posição de interação trabalhando empatia, usando a afinidade como fator favorável. A aplicação da atividade teve resultados positivos, combatendo a indisciplina, gerando debates, fixação do conteúdo e companheirismo, melhorando o andamento dos próximos conteúdos, assim como a adesão desse método por outros professores da escola.
Palavras-chave: Aprendizagem cooperativa; Álgebra; Currículo; Relato; Ensino Fundamental.
Influence of Rheological Characteristics and Stability of Water-Based YSZ Suspensions on the Morphology of Plasma Sprayed Thermal Barrier Coatings
Authors: Yaghtin Maryam , Yaghtin Amirhossein , Tang Zhaolin , Troczynski Tom , Tang Zhaolin 
Published: June 2021

Abstract
In suspension plasma spraying (SPS); the use of water based suspensions provides a cheaper; safer and more environmentally friendly alternative to organic liquids. However; due to the physical properties of water; producing a water based SPS coating with desirable microstructure has so far been elusive. In this study; the effects of pH and dispersant on the rheology and stability of YSZ water based suspensions were investigated. PEI; PBTCA and α-Terpineol were used as dispersant polymers. The stabilized suspensions were deposited by Axial III plasma spray system and the relationship between suspension parameters and the atomized droplet size and the final coating microstructure was studied. The results showed that a combination of Terpineol dispersant with pH adjustment to 2.5; could lead to a SPS coating with columnar microstructure having 17.4 vol.% porosity.
Ensemble Methods for APS In-Flight Particle Temperature and Velocity Prediction Considering Torch Electrodes Ageing
Authors: Yu K.R. , Cojocaru C.V. , Ilinca F. , Irissou E. 
Published: June 2021

Abstract
In an atmospheric plasma spray (APS) process, in-flight powder particle characteristics, such as the particle velocity and temperature, have significant influence on the coating formation. The nonlinear relationship between the input process parameters and in-flight particle characteristics is thus of paramount importance for coating properties design and quality control. It is also known that the ageing of torch electrodes affects this relationship. In recent years, machine learning algorithms have proven to be able to take into account such complex nonlinear interactions. This work illustrates the application of ensemble methods based on decision tree algorithms to evaluate and to predict in-flight particle temperature and velocity during an APS process considering torch electrodes ageing. Experiments were performed to record simultaneously the input process parameters, the in-flight powder particle characteristics and the electrodes usage time. Various spray durations were considered to emulate industrial coating spray production settings. Random forest and gradient boosting algorithms were used to rank and select the features for the APS process data recorded as the electrodes aged and the corresponding predictive models were compared. The time series aspect of the data will be examined.
Cold Spray MCrAlY Coatings on Single-Crystal Ni-Base Superalloys: A Substrate Perspective
Authors: Guo Deliang , Jodoin Bertrand , Zhao Linruo 
Published: June 2021

Abstract
The hot-section components of modern gas turbines (e.g., turbine blades and vanes) are typically manufactured from Ni-base superalloys. To develop the γ/γ' microstructure that imparts superior thermomechanical and creep properties, Ni-base superalloys usually require three distinct heat treatments: first a solution heat treatment, followed by primary aging, and finally secondary aging. To achieve oxidation resistance, MCrAlY coatings are applied on the superalloy components as either environmental coatings or bond coats for thermal barrier coatings. In this study, the effects of different processing sequences on MCrAlY coating characteristics and short-term isothermal oxidation performance were investigated. Specifically, cold spray deposition of NiCoCrAlTaY coatings was carried out on single-crystal Ni-base superalloy substrates that underwent various degrees of the full heat treatments prior to being coated. The remaining required heat treatments for the superalloy substrates were then performed on the coated samples after the cold spray deposition. The microstructures of the CMSX-4 substrates and NiCoCrAlTaY coatings were characterized after each heat treatment. Isothermal oxidation performance of the coated samples prepared using different sequences was evaluated at 1100°C for 2 hours. The results suggested a promising procedure of performing only solution heat treatment on the superalloy substrate before coating deposition and then primary aging and secondary aging on the coated samples. This processing sequence could potentially improve the oxidation performance of MCrAlY coatings, as the aging processes can be used to effectively homogenize coating microstructure and promote a thin thermally grown oxide (TGO) scale prior to actual isothermal oxidation.
Using a DOE Approach to Optimize a LVPS Bond Coat and APS Top Coat for TBC Systems
Authors: Loza Jose J. , Laul Komal , Carroll Mickey , Pike Bobby 
Published: June 2021

Abstract
Acquisition of a new LVPS and APS coating system at Delta Air Lines necessitated optimization of the coating parameters on both systems, especially for application of bond coat (LVPS) and top coat (APS) for a TBC coating system. To expedite the coating optimization, it was determined that a design of experiments (DOE) approach would best enable the establishment of the operating window for the two systems. Samples prepared were primarily evaluated for their performance while exposed to a cyclic oxidation cycle. Samples were also evaluated for the microstructure and composition using energy dispersive spectroscopy (EDS) analysis. Samples from the ceramic coating DOE were also evaluated for their erosion characteristics. Results indicate a low correlation between the individual bond coat parameters evaluated to the furnace cycle life. However, the top coat spray parameters were found to have a greater correlation to furnace cycle life and erosion performance.
Cold Spray Sn Coating on the Carbon Fiber Reinforced Polymer
Authors: Sun Jiayu , Yamanaka Kenta , Chiba Akihiko , Ichikawa Yuji , Saito Hiroki , Ogawa Kazuhiro 
Published: June 2021

Abstract
Because of their high specific strength, carbon fiber reinforced plastics (CFRPs) are widely used in the aerospace industry. Metallization of CFRP by cold spraying as a surface modification method can improve the low thermal resistance and electrical conductivity of CFRP without the need for high heat input. Herein, we cold spray a Sn coating on cured CFRP substrates and examine the Sn/epoxy interface. The results suggest that the Sn coatings are successfully obtained at a gas temperature of 473 K and indicate no severe damage to the CFRP substrates. The stress and plastic strain distributions at the cross-section of the Sn/CFRP interface when a Sn particle is impacted onto the CFRP substrate are obtained using the finite element method.
Novel Liquid Fuel HVOF Torches Fueled with Ethanol: Optimization and Erosion Wear Response of Cr3C2-NiCr Coatings
Authors: Liu Shaowu , Moliere Michel , Liao Hanlin 
Published: June 2021

Abstract
In this work, a novel liquid fuel HVOF process fueled with ethanol was used to prepare 75wt%Cr3C2–25wt%NiCr coatings on AISI304 stainless steel substrate. Taguchi method was employed to optimize the spray parameters (ethanol flow rate, oxygen flow rate, powder feed rate and standoff distance) to achieve better erosion resistance at 90° impact angle. The results indicated that ethanol flow rate and oxygen flow rate were identified as the highly contributing parameters on the erosion wear loss. The important sequence of the spray parameter is ethanol flow rate &gt; oxygen flow rate &gt; standoff distance &gt; powder feed rate. The optimal spray parameter (OSP) for minimum erosion wear loss was obtained under ethanol flow rate of 28slph, oxygen flow rate of 420slpm, powder feed rate of 76.7 g/min and standoff distance of 300mm. The phase composition, microstructure, hardness, porosities, and the erosion wear behaviors of the coatings have been studied in detail. Besides, erosion wear testing of the optimized coating was conducted at 30°, 60° and 90° impact angle using air jet erosion testing machine. The SEM images of the erodent samples were taken to analyze the erosion mechanism.
Hybrid Additive Manufacturing Technology—Induction Heating Cold Spray
Authors: Ortiz-Fernandez R. , Jodoin B. 
Published: June 2021

Abstract
This present work investigates the effect of electromagnetic fields on cold spray processes by means of an induction-heating cold spray (IHCS) system. Aluminum powder was cold sprayed onto inductively heated Ti6Al-4V (Ti64) substrates. These materials were selected to minimize the mechanical contribution to coating adhesion. As a result, changes in coating adhesion strength can be attributed to improved metallic bond formation due to the effect of the electromagnetic field. Four different initial substrate surface temperatures were used in the study to assess the role of initial temperature as well. Deposition efficiency and adhesion and tensile strength measurements were recorded and are used to characterize the hybrid coating process and compare it with traditional techniques.
Investigation on Microstructural Characteristics and Mechanical Properties of Thermally Sprayed Fe-Base Composites Reinforced with Different Ceramic Particulates
Authors: Azarmi Fardad , Tangpong X.W. 
Published: June 2021

Abstract
Three different coatings were deposited using the Detonation Gun Spraying (DGS) technology from steel powders alone, and steel powers mixed with Fe3C and SiC particles, respectively. The microstructural characteristics of these coatings were examined and the hardness of each type of coating was studied. The morphology and structure of the feedstock powders were affected by the exposure to high temperature during the spraying process and rapid solidification of steel powders that resulted in the formation of an amorphous structure. The unreinforced steel coating had the highest hardness among the three types of coatings, possibly due to a higher degree of amorphization in the coating compared to the other two samples. The microstructural observation confirmed the formation of dense coatings with a layered structure with good connectivity between layers with minimum defects and porosities in the interfacial regions.
Influence of the Low-Pressure Cold Spray Operation Parameters on Coating Properties in Metallization of Ceramic Substrates Using Copper and Aluminum Composite Powder
Authors: Yu Minjae , Saito Hiroki , Bernard Chrystelle , Ichikawa Yuji , Ogawa Kazuhiro 
Published: June 2021

Abstract
The low-pressure cold spray (LPCS) technique could be an attractive method for copper metallization of ceramic substrates to power module applications due to its one-step quick and low-temperature process. However, manufacturing pure copper coating on a ceramic substrate by LPCS is still challenging due to its low deposition efficiency and poor adhesion strength. Our previous study successfully demonstrated the possibility of obtaining a zirconia substrate's metallization by using a feedstock powder mixture of copper and aluminum. However, the copper content in the coating was not high enough for power module applications. Therefore, in this study, we aim to improve the copper content in the coating layer composed of the composite powder deposited by LPCS on alumina and zirconia substrates. The influence of the gas pressure and standoff distance on the copper content and coating thickness are evaluated. The coating build-up with a high copper content and thickness is highly dependent on the kinetic energy of particles, enhanced by high gas pressure and short stand-off distance.
Effect of Secondary Component Properties when Cold Spraying Mixed Metal Powders on Carbon Fiber Reinforced Polymers
Authors: Liberati Andre C. , Che Hanqing , Yue Stephen , Vo Phuong 
Published: June 2021

Abstract
In previous studies at McGill University, tin was successfully cold sprayed onto carbon fiber reinforced polymers (CFRPs). A “crack-filling” mechanism was described as the deposition mechanism that allowed deposition of tin onto the CFRP. Improving the coating conductivity for lightning strike protection (LSP) purposes was achieved by adding other metal powders (aluminum, copper, zinc) to tin and cold spraying on the CFRP. At the same time, it was noticed that the addition of this secondary component (SC) provided an increase in deposition efficiency (DE), tamping was initially hypothesized to explain this improvement, thus prompting a study solely on the effect of SC hardness, which is reported elsewhere in this conference. However, it is recognised that other powder characteristics may also be influencing the DE. Thus, in this study, SCs with a wider variety of particle sizes, morphologies, densities and hardness values were mixed with tin and sprayed on CFRPs. The effect of SC properties on tin deposition is discussed and an optimal combination of SC properties for cold spraying of tin is suggested.
Effect of Pre-Treatment on Substrates for Metal Coatings Fabricated by Low Pressure Cold Spray Technique
Authors: Saito Hiroki , Ebihara Hiroaki , Ichikawa Yuji , Ogawa Kazuhiro 
Published: June 2021

Abstract
Low pressure cold spraying is an attractive technique for onsite metal coating fabrication due to its compactness and portability. However, the bonding strength of the coating prepared by low pressure cold spraying is generally low, which restricts the further applications in engineering and industrial fields. To improve the bonding strength, pre-treatment on substrate surface can be an effective procedure. In this study, a low-temperature plasma treatment was applied to a pretreatment technique, and the effect of the treatment on particle bonding was compared with that of a laser treatment. Copper coatings on aluminum and copper substrates were selected and studied as basic metal materials. The SEM observation results show that the particle adhesion rate significantly increases by the laser and plasma treatments, due to the removal of the native oxide films on the substrates. The particle bonding on the plasma-treated substrate reveals better interfacial adhesion with less gap compared with the laser-treated one. The pre-treatment by low-temperature plasma can be an attractive technique to assist the cold spraying process due to the oxide removal ability and no thermal effect which can apply a wide range of materials.
Wear and Corrosion Behavior of Cold Gas Sprayed Stainless-Steel Coatings Using Solution-Hardened AISI 316L Powder
Authors: Lindner Thomas , Kutschmann Pia , Grimm Maximilian , Löbel Martin , Fiebig Jochen 
Published: June 2021

Abstract
Due to their excellent corrosion resistance, austenitic stainless steels are suitable for surface protection applications. However, the application potential is often limited by the low wear resistance. An interstitial hardening of the surface layer area can solve this problem for massive wrought alloys. Further potential for improvement lies in the transition to surface technology. For this purpose, powder feedstock of the stainless-steel grade AISI 316L was gas nitrocarburized at low temperatures. The formation of a metastable expanded austenitic phase was achieved. Subsequently, the processing was carried out by cold gas spraying. Due to the simultaneously high process kinetics and low thermal load, dense coatings were produced while maintaining the metastable state of the feedstock. When compared to solid reference systems, the scratch resistance saw a marked improvement.