Basis Of Method Research Articles

Strain Engineering for Electrocatalytic Overall Water Splitting.

Strain engineering is a novel method that can achieve superior performance for different applications. The lattice strain can affect the performance of electrochemical catalysts by changing the binding energy between the surface-active sites and intermediates and can be affected by the thickness, surface defects and composition of the materials. In this review, we summarized the basic principle, characterization method, introduction strategy and application direction of lattice strain. The reactions on hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) are focused. Finally, the present challenges are summarized, and suggestions for the future development of lattice strain in electrocatalytic overall water splitting are put forward.

Sliding-window cross-correlation and mutual information methods in the analysis of solar wind measurements

Context. When describing the relationships between two data sets, four crucial aspects must be considered, namely: timescales, intrinsic lags, linear relationships, and non-linear relationships. We present a tool that combines these four aspects and visualizes the underlying structure where two data sets are highly related. The basic mathematical methods used here are cross-correlation and mutual information (MI) analyses. As an example, we applied these methods to a set of two-month’s worth of solar wind density and total magnetic field strength data. Aims. Two neighboring solar wind parcels may have undergone different heating and acceleration processes and may even originate from different source regions. However, they may share very similar properties, which would effectively “hide” their different origins. When this hidden information is mixed with noise, describing the relationships between two solar wind parameters becomes challenging. Time lag effects and non-linear relationships between solar wind parameters are often overlooked, while simple time-lag-free linear relationships are sometimes insufficient to describe the complex processes in space physics. Thus, we propose this tool to analyze the monotonic (or linear) and non-monotonic (or non-linear) relationships between a pair of solar wind parameters within a certain time period, taking into consideration the effects of different timescales and possible time lags. Methods. Our tool consists of two parts: the sliding-window cross-correlation (SWCC) method and sliding-window mutual information (SWMI) method. As their names suggest, both parts involve a set of sliding windows. By independently sliding these windows along the time axis of the two time series, this technique can assess the correlation coefficient (and mutual information) between any two windowed data sets with any time lags. Visualizing the obtained results enables us to identify structures where two time series are highly correlated, while providing information on the relevant timescales and time lags. Results. We applied our proposed tool to solar wind density and total magnetic field strength data. Structures with distinct timescales were identified. Our tool also detected the presence of short-term anti-correlations coexisting with long-term positive correlations between solar wind density and magnetic field strength. Some non-monotonic relationships were also found. Conclusions. The visual products of our tool (the SWCC+SWMI maps) represent an innovative extension of traditional numerical methods, offering users a more intuitive perspective on the data. The SWCC and SWMI methods can be used to identify time periods where one parameter has a strong influence on the other. Of course, they can also be applied to other data, such as multi-wavelength photometric and spectroscopic time series, thus providing a new tool for solar physics analyses.

Research on the Reform of the Course “Fundamental Principles of Engineering Structures” in the Context of School-Enterprise Cooperation and Integration of Production and Education

The course “Fundamental Principles of Engineering Structures” is one of the compulsory courses for undergraduate students majoring in civil engineering, structural engineering, and bridge engineering. It mainly introduces the basic concepts, principles, and design methods of engineering structures. The course’s emphasis lies in the integration of theory and practice, aiming to enable students to acquire fundamental theoretical knowledge of engineering structures in the classroom and to consolidate this knowledge through practical activities such as experiments and design, thereby enhancing their comprehensive abilities. Therefore, the teaching reform of the course on fundamental principles of engineering structures should start with improving students’ practical abilities and strive to achieve organic integration of theory and practice. This paper explores how the teaching reform of the course should be conducted against the backdrop of course ideological and political education, mainly focusing on the integration of school-enterprise cooperation and production-education integration. Firstly, the author analyzes the current issues and challenges from the perspectives of school-enterprise cooperation and production-education integration, and then proposes corresponding measures for the reform of course teaching, including establishing a curriculum system in line with modern engineering practices, fully leveraging the role of teaching design, and stimulating students’ interest in learning, among others. It is hoped that this research can provide some reference and inspiration for developing relevant teaching reforms in the course of fundamental principles of engineering structures.

Transformation of interaction between banks and leasing companies in the context of geopolitical challenges

Aim. To develop proposals and practical recommendations on the transformation of interaction between banks and leasing companies, which will allow to increase the volume of their interaction, as well as to improve its efficiency due to additional commission income and increased profitability.Objectives. To study and systematize macroeconomic indicators of the segments of banking and leasing services in Russia; to propose a new model of interaction between a bank and a leasing company, which is aimed at increasing its commission income and profitability; to assess the effectiveness of the developed recommendations and their potential to increase the financial result from the financing of leasing operations by the bank.Methods. The author used a set of existing basic research methods, allowing to ensure the reliability of conclusions, including economic and mathematical modeling, system approach, sample observation, comparison, analysis and synthesis.Results. Leasing is a part of credit activity of many commercial banks, forming their infrastructural elements, and occupies the largest share in the financial market of Russia after bank loans. The interest of domestic banks in financing leasing operations is conditioned by a number of factors: in the conditions of increasing competition in the market of financial services commercial banks have to develop and implement financial innovations in order to obtain additional income, which leasing allows them to do; availability of solid loan collateral in the form of the leasing object and the possibility of obtaining additional commission; availability of ready leasing infrastructure, i.e. rapidly developing market of leasing services and a whole range of effective leasing services; availability of leasing services in the form of the leasing object and the possibility of obtaining additional commission fees; availability of a ready-made leasing infrastructure, i.e. a rapidly developing market of leasing services and a whole range of effective leasing services. Despite the fact that both segments of the financial market the segments of banking and leasing services — are developing, their interaction needs transformation, since the banking business is under-receiving income from the leasing segment. Among the reasons for this situation are the decline in the volume of new leasing transactions under the influence of the geopolitical crisis, which exacerbated the problem of the shortage of leasing items; early termination of a number of large leasing transactions, including those associated with the withdrawal of foreign business from Russia; reduction of net interest margin caused by the outstripping growth of funding costs over the return on assets of the banking sector. The relevance of the research topic is traced in the need to develop measures to transform the interaction between Russian commercial banks and leasing companies in the context of geopolitical challenges, which will be aimed at improving the performance of credit organizations. For this purpose it is proposed to use additional sources of interest and commission income of commercial banks in financing leasing activities: increase in net interest margin by increasing the share of financing small and medium-sized businesses; increase in interest income due to accelerated reimbursement of value added tax (VAT); commission income from insurance business; attraction of small and medium-sized businesses in the regions of Russia, where Islamic traditions prevail in the country.Conclusions. Proposals and practical recommendations concerning qualitative transformation of interaction between banks and leasing companies, assuming the use of additional sources of interest and commission income of commercial banks in the financing of leasing activity, allows to solve the important problem of loss of income of banks in the conditions of geopolitical challenges.

EMPLOYEE JOB SATISFACTION AND EMPLOYEE PRODUCTIVITY IN NIGERIA'S FEDERAL CIVIL SERVICE: AN EMPIRICAL EXAMINATION OF COMMUNICATION AS METRIC FOR JOB SATISFACTION

Purpose: The study examined the effect of employee job satisfaction on employee productivity, assessing the impact of communication as an indicator of job satisfaction in the Nigerian federal civil service. A part of efforts to achieve the eight Sustainable Development Goal of Decent Work and Economic Growth by 2030. Theoretical Framework: Low performance and high turnover rates can result from job dissatisfaction which has been peculiar case in the public and private sector, attempt to deal with it has not been yielding positive result in the civil service in Nigeria (Rinny et al., 2020; Sadiq et al. 2020). Therefore, there is need to empirically investigate the impact of communication on employee productivity in Nigerian federal civil service which lacks sufficient research. Methodology: The study used a survey research design and purposive non-probability sampling where the data are collected through the distribution of 2,836 questionnaires to the staff of 10 Nigerian federal civil services. In order to gather data for the study, Demographic data were analyzed using basic descriptive statistical methods like mean, percentages, and standard deviations, while inferential statistics were analyzed using econometric methods like multiple and logistic regression, as well as Karl Pearson's Product Moment Correlation Coefficients. Findings: Finding of the study showed that employee productivity is strongly and favorably affected by (communication) as proxy for job satisfaction. Nonetheless, in the Nigerian Federal Civil Service, the interaction of work environment moderating between communication had no impact on employee productivity. Research, Practical & Social Implication: The study recommends that organizations should establish transparent and accessible communication channels that involves implementing regular feedback mechanisms to ensure that employees feel heard and valued Originality/Value: It is quite unusual with previous study using communication as proxy for job satisfaction as an independent variable, Also, none of the previous used work environment as mediating variable in the interplay between communication and employee productivity in civil service in Federal Capital Territory Abuja Nigeria.

Modern metaphor research in Russia: Trends, schools and results

This article focuses on various trends and linguistic approaches to metaphor studies in Russia (2019-2023). The latter deal with different types of metaphors, process of metaphor formation and the use of metaphors in discourse. The basic methods of investigation include comparative, inductive, generalization and descriptive approaches. The article summarises new results in modern studies of metaphor on data from Slavic, Romance and Germanic languages. In the paper, we show the role of metaphor both as a trope and a cognitive operation in monolingual and comparative studies. Alongside these traditional areas, we discuss the results of metaphor studies in multimodal texts and corpora. Multimodal texts are frequently constructed on the intersection of mental, semiotic and semantic fields. Corpora, which have proved to be a convenient source of recent and reliable data, present another modern sphere of investigation of metaphoric potential in Russian studies. We discuss such important areas of metaphor studies as the interdisciplinary approach, pluralism of methods, critical attitudes to universalism, emphasis on cultural features of communication and discourse, and the blending of rhetorical and cognitive methods.

Research Progress on the Geomechanical Properties of Block-in-Matrix Rocks.

The differences in geomechanical properties and the uncertainty in the spatial distribution of Bimrock pose significant challenges to the construction and disaster prediction of geotechnical engineering. To clarify the geomechanical characteristics of Bimrock, this paper summarizes the basic concepts and classification methods of Bimrock at home and abroad. It discusses the methods and characteristics of determining the geometric features of Bimrock blocks and explores the influencing factors and laws of failure modes and strength under different stress states of Bimrock. The study finds that the failure mode of Bimrock is mainly influenced by factors such as block proportion, degree of welding between blocks and matrix, strength ratio between blocks and matrix, and geometric properties of blocks. Among these factors, block proportion is the most significant, and the degree of welding is a controlling factor. However, due to the complexity of Bimrock structures, there is a lack of applicable methods and mechanical models for the evaluation of geomechanical characteristics of Bimrock in engineering practice. This article also explores the influence and research methods of the geological characteristics of Bimrock in slope and tunnel engineering and, finally, provides prospects for the future research trends relating to Bimrock.

Study of irrigation aspect in the interconnection system of Telaga Tanjung and Singin Ponds in Tabanan Regency

Interconnection is a channel that links multiple water channel systems with those downstream of a river area. The proposed system will utilize existing canals in Gadungan, Matan, and Unun Irrigation Areas, extending to the Lambuk Reservoir dam system. The problem is that irrigation areas downstream of the Lambuk Reservoir are Lambuk (726 ha), Babakan Anyar (42 ha), and Lanyah (281 ha) experience water shortages (planting intensity of 170% to 200%) during the dry season. The study utilized water balance methods in rice fields, the basic year method for main discharge at weirs, and interconnection channel analysis for water needs calculation. From the water balance analysis, the Singin System cannot make a new interconnection channel to the Lambuk Reservoir because the available water in each reservoir can only irrigate the Matan and Unun Irrigation Areas. From the Telaga Tunjung System, there is still a lot of water available, especially during the rainy season, so that it can supply the reservoir for the Lambuk Reservoir. This means that the interconnection system from this reservoir still needs to be created from the primary channel of the Gadungan Irrigation Area.

Laser‐Induced Breakdown Spectroscopy Online Quantitative Analysis for Laser Processing

Plasma fluctuations, the uncertainty of laser ablation, and bremsstrahlung limit the identification of online element analysis during laser processing and cause difficulty in achieving concentration results with sufficient accuracy and repeatability. A laser‐induced breakdown spectroscopy (LIBS) online monitoring system with plasma spatial filtering and spectral screening is proposed to solve this problem. In this system, the high‐frequency ablation noise component of the plasma is eliminated using a specially designed optical Fourier filtering structure, and a spectral screening system based on plasma time waveform monitoring is used to suppress the influence of plasma fluctuations. Without noise filters or algorithm optimizations and based only on the basic internal standard method, the calibration curves of all nine elements in the alloy sample exhibits a Pearson's R2 value ranged from 0.91 to 0.99, with a mean of 0.94. The relative standard deviations are all in the range of 3.5%–8.4% with a mean of 5.4%. The accuracy and repeatability are comparable to those of typical LIBS systems.

Урожайность сортов яровой пшеницы на фоне разных приёмов основной обработки почвы в засушливых условиях

Abstract. The article provides data on the reserves of productive moisture, the content of nitrate nitrogen, and the yield of spring wheat varieties when grown under different backgrounds of basic tillage. The purpose of the research is to study the response of spring soft and durum wheat varieties to the methods of basic tillage. Methods. The object of research is 3 varieties of spring soft wheat and 2 varieties of spring durum wheat. The experiments were carried out in the central zone of the Orenburg region. For 5 years, two options for basic soil cultivation were studied: plowing to a depth of 23–25 cm and moldless loosening to a depth of 25–27 cm. Scientific novelty. The reaction of spring wheat varieties to the methods of basic tillage, taking into account the reserves of productive moisture and the content of nitrate nitrogen in the soil, in the arid conditions of the Orenburg Cis-Urals was revealed. Results. The reserves of productive moisture during the sprouting phase of spring wheat in a meter layer of soil were satisfactory (less than 130 mm) for four years out of five years of research, and good for one year (150-153 mm). The advantage of non-moldboard tillage was noted in all years of research with the exception of 2019, when the mouldboard background contained 18 mm more soil moisture. Depending on weather conditions, the amount of nitrate nitrogen in the soil varied from very low values in 2022 to high and very high values in 2017 and 2019–2020. The yield of spring wheat, on average according to experience, was 0.6 c per 1 ha higher against the background of moldless loosening. The varietal response to basic soil tillage methods has been established. The Uchitel’ variety did not respond to processing techniques. For other varieties, the difference in favor of non-moldboard tillage ranged from 0.4 centners per 1 hectare for the Tulaykovskaya zolotistaya variety, to 0.7–0.8 centners per 1 hectare for the varieties Ul’yanovskaya 105, Orenburgskaya 10, Bezenchukskaya 210.

Development of Synthesis as a General Logical Method of Cognition in the Process of Teaching Mathematics of Students and Future Teachers

General logical cognitive actions form the basis of almost all cognitive methods. This determines the necessity of their purposeful formation in the process of subject teaching. A special role in the development of cognitive methods belongs to mathematics, in the process of teaching which these actions manifest themselves in the most explicit form. In the article we consider the formation of synthesis as a basic general logical method. The purpose of our study is to develop approaches to the organization of subject-based teaching aimed at the formation and development of synthetic thinking of school students and teacher education students. The methodology of the research is the theory of funding of logical constructions, developed on the basis of the concept of funding in education (V. D. Shadrikov, E. I. Smirnov). The results of the study. Examples demonstrating the main types of synthesis in mathematics learning are considered. These types include: synthesis as a leading action in the construction a mathematical model and synthesis as a representation of a logically justified solution to a problem. The problems of synthesis implementation by students in the process of solving mathematical problems are analyzed. The specificity of educational tasks that contribute to the formation of synthetic thinking is studied. The role of combinatorial tasks as tasks with prevailing logical component in the formation of synthetic thinking of students is described. In conclusion, on the basis of the theory of funding, the typification of types of synthesis in school mathematical education is proposed.

Human capital management – values, competencies, and motivation – concerning Industry 4.0

The article aims to determine the current situation in economic subjects (ESs), what values and competencies are for managers and executives, and what motivational factors are essential for financial entities in the era of Industry 4.0. The article used standard scientific methods, such as analysis, synthesis, induction, and deduction, but also methods, such as content analysis of professional and scientific literature, comparison, modelling, and basic statistical methods, which verified the dependencies between the selected elements. The article processes data from a questionnaire survey conducted in 2020 (905 respondents) and 2021 (561 respondents). The respondents who filled out the questionnaire survey were managers or owners of ESs, which are based in Slovakia and are classified as micro, small, medium, or large enterprises. We found in the study that there is a dependence between the employment orientation of managers and the use of career motivation factors, as well as between the passion for work and the creativity of employees, and between the technological and IT skills of managers and executive employees. It is surprising that ES in Slovakia consider soft skills more important than technological ones despite the pressure to support and develop people’s digital skills.

A two-level fusion model of vibro-acoustic signals for centrifugal fan blade crack detection

Blade crack detection is the key to ensuring the smooth and safe operation of centrifugal fans. However, a single vibration signal is difficult to fully reflect the health state of the blade and is susceptible to noise interference in the industrial field, which makes it difficult to detect blade cracks. Therefore, a two-level fusion model of vibro-acoustic signals is proposed for blade crack detection of centrifugal fans. Firstly, based on the designed correlated degree of cyclostationarity fusion rule, the data-level fusion of multi-source homogeneous vibro-acoustic signals is completed, and the fused signals with more obvious fault features are obtained. Then, a one-dimensional feature pyramid network is proposed to extract the vibro-acoustic features and generate initial decisions. Finally, a basic probability assignment acquisition method based on the precision of the initial classifiers and a weighted average method based on the Pignistic probability distance are proposed to minimize the conflict between multi-source evidence, and the Dempster-Shafer evidence theory method is used to obtain the blade crack detection results. The effectiveness of the proposed method is verified by the centrifugal fan blade crack detection experiments. Compared with other related methods, the proposed method has better detection performance and stronger robustness.

Automata-based Software Engineering for Control System Design and Verification

The automata composition is defined as the basic language construct of automata programming. Incorporating automata composition into an arbitrary programming language allows the development of automata programs in that language. Methods for specification and verification of reactive systems are defined in detail. All kinds of correctness formulas for a reactive system with respect to its specification are defined. In addition, correctness formulas for verification using the full invariant of the reactive system are developed. The Event-B manual begins with a brilliant illustration of the basic Event-B methods using the example of a car traffic control problem on a narrow bridge. However, the latter refinement in this illustration generates a complex cumbersome program. A simpler and shorter solution to this problem was presented in our work [7] using automata programming approach. Our solution was not easy because 4 non-trivial bugs were found by verification in Event-B. This paper describes our third attempt to construct a short simple automata program to solve this problem. Verification of the automata program in Event-B and Why3 systems was carried out. No errors were found. For verification, a reactive system model is built on Why3, which is simpler and more universal than the why3-do model.

Faktor-Faktor Yang Memengaruhi Volume Impor Beras Di Indonesia

<em>Rice is one of the agricultural products that experience many problems in providing national food stocks. Constraints on rice stocks in Indonesia have resulted in price increases, especially for low-income people. Insufficient rice production encourages rice imports by the government to meet national needs. The research aims to determine the factors that influence rice imports in Indonesia. The basic research method is a quantitative descriptive method. Secondary data was used in 1993-2022. Data analysis uses multiple linear regression. The results of the analysis show: (1) Together, the variables of rice harvest area, population, rupiah exchange rate, rice consumption, and rice stock have a significant effect on rice imports. (2) The variables of rice harvest area, rupiah exchange rate, and rice stock do not individually have a significant effect on rice imports. On the other hand, the variables of population and rice consumption have a significant effect individually. (3) The variables of population and rice consumption have a positive and significant influence on rice imports. The government is advised to focus on rice import policies by considering fluctuations in domestic consumption and population which have a significant impact, while also monitoring the stability of the rupiah exchange rate to anticipate potential impacts in the future.</em>

Advanced Fog Harvesting Method by Coupling Plasma and Micro/Nano Materials.

Harvesting fog is a potential and effective way to alleviate the crisis of water resource shortage. A highly efficient and economical fog harvesting method has always been a global and common goal. Here, a promising fog harvesting method by coupling plasma and micro/nano materials is proposed, which can achieve 93% fog collection efficiency with consuming power of only 0.76 W/0.04 m2. The basic method is to utilize nanoparticles to decorate both the discharge electrode and the collecting electrode of the micro/nano electrostatic fog collector. For the discharge electrode, the nanoparticles can achieve an order of magnitude higher electric field strength and a 28.6% decrease in the operating voltage (14 kV decreases to 10 kV). For the collecting electrode, a novel composite structure of hydrophobic/hydrophilic (HB/HL) is proposed. The core advantage is the directional droplet transport at the junction of HB and HL caused by surface tension can adjust the accumulated droplets on the two sides, which avoids the droplet residue and mesh blockage in the general structure. This technology provides an innovative approach for the collection of microdroplets and a new design idea for the fog collector to deal with the water crisis.

Assessing evidence-based practice competencies of undergraduate nursing students using a developed multi-criteria decision-analysis model

AimThe developed multi-criteria decision analysis model was used to identify the inter-influence relationships and key factors affecting the EBP competencies of UNSs, to assess the EBP competencies of UNSs and based on these results, to formulate an improvement strategy to enhance the EBP competencies of UNSs. BackgroundEBP is considered a core competency in international nursing practice. However, few studies have developed EBP evaluation models and applied them to assessing and improving the EBP competencies of UNSs. DesignThis is a quantitative study with multi-criteria decision-analysis model. MethodsFirstly, the questionnaire was designed based on the characteristics of the DEMATEL and VIKOR-AS methods, which was completed by 17 nursing experts from a case hospital in Zhejiang Province, China. Subsequently, the DEMATEL method was used to analyze the inter-influence relationships among various criteria to determine their respective weights. Finally, the VIKOR method is utilized to integrate multiple criteria and their relative weights to assign comprehensive scores to each UNSs. ResultsThe use of the DEMATEL method reveals that “Knowledge (C1)”, “Mastering the basic scientific research methods during the study of the undergraduate courses (C11)”, “Being able to consult clinical experts appropriately when encountering problems in clinical practice (C23)” and “Understanding the importance of reading journals related to the nursing profession regularly (C34)” were critical influencing factors. “Skill (C2),” “Being able to explain the essential roles of the best research evidence in determining clinical practice (C15),” “Being able to apply the collected research evidence to the individual case in nursing care (C25)” and “Paying attention to using the evidence-based nursing practice concept to determine the best clinical practice (C35)” were the most influential factors. According to the VIKOR method, the performance of the UNSs in the case hospitals in terms of EBP competencies from highest to lowest was Student C, Student B and Student A. However, all of these students suffered from deficiencies at the knowledge level. ConclusionsThe application of the DEMATEL and VIKOR methods provides a systematic and comprehensive approach to the assessment of EBP competencies of UNSs. The lack of EBP competencies of UNSs in case hospitals is mainly reflected in knowledge level. To improve UNSs’ EBP competencies, medical schools and hospital educators should propose short- and long-term strategies to improve knowledge.

Forecasting and planning for special events in the pulp and paper supply chains

ABSTRACT Due to global warming, flood is an increasing threat to companies operating in the pulp and paper industry. The impact of this threat needs to be managed. We deploy a qualitative investigation into how paper manufacturers can forecast and mitigate the impact of special events, most notably floods, across their supply chains. A grounded theory approach using semi-structured interviews held with supply chain consultants in three stages allowed for topic categories emerging during previous interviews to be explored. Analysis of these interviews uncovered tactics unique to the pulp and paper industry. The findings are three-fold. First, paper manufacturers should focus on basic forecasting methods which they are capable of, such as subscribing to flood warnings, rather than poorly executing advance machine learning forecasts. Second, planning is of equal importance to forecasting: integrated business planning should guide the process. Third, business execution should involve a proactive approach to decision-making which trusts data and has people that nurture and drive the process.

Ability of Selected Monoterpenes to Reduce Fe(III) Ions Being Pro-Neurodegenerative Factors: Tests Based on a FRAP Reaction Extended to 48 Hours.

Monoterpenes are secondary plant metabolites, and such volatile compounds have antioxidant, antibacterial, antiviral, and enzyme inhibitory properties. These compounds are also able to reduce the potentially pro-neurodegenerative trace metal ions that can be sources of free radicals. One basic method used to evaluate the ability of chemical compounds to reduce Fe(III) is FRAP. To date, most studies based on a FRAP assay were performed within several dozen minutes. However, taking into account the diversity of compounds, it is justified to observe their activity over a much longer period of time. The present study aimed to observe the activity of isopulegol, γ-terpinene, α-terpinene, linalool, carvone, citral, and α-phellandrene over a 48 h period. Our study indicates that the lengthened reaction period enhanced activity from several dozen to several hundred percent. The obtained results also revealed an explicit high correlation of the increase in the activity of compounds with the increase in monoterpene concentration. Due to the hydrophobic character of monoterpenes, the FRAP method was modified by the addition of Tween 20. The highest activity was obtained for α-terpinene and γ-terpinene.

Tomographic Reconstruction of Hypersonic Aircraft Flowfields in Large-Scale Wind Tunnel Experiments

Three-dimensional flowfield features around a hypersonic aircraft model were reconstructed using a computed tomography background-oriented schlieren technique. Datasets of projection images were acquired in hypersonic wind tunnel experiments conducted at the Japan Aerospace Exploration Agency’s 0.5m hypersonic wind tunnel facility, by rotating the test model with an increment of 2° azimuth. A telecentric optical configuration was applied to the background-oriented schlieren measurement at the large-scale hypersonic wind tunnel facility. A basic tomographic reconstruction method, such as filtered backprojection, was used to reconstruct the projection datasets with some combination of denoising calculations. Results showed that the reconstructed flowfield was first noisy without denoising. With the denoising considerations proposed in this study, the flow physics, such as oblique shock waves emanating from the vehicle nose tip and engine lip, were clearly visualized. Therefore, the telecentric optical setup and denoising processes proposed in this study can successfully reconstruct a complex three-dimensional flowfield obtained at a large-scale wind tunnel facility. This setup and denoising process can also apply to other applications in large-scale wind tunnel experiments.