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This study aims to improve the availability of regenerative braking for urban metro vehicles by introducing a sensorless operational temperature estimation method for the braking resistor (BR) onboard the vehicle, which overcomes the vulnerability of having conventional temperature sensor.

In this study, the energy model based sensorless estimation method is developed. By analyzing the structure and the convection dissipation process of the BR onboard the vehicle, the energy-based operational temperature model of the BR and its cooling domain is established. By adopting Newton's law of cooling and the law of conservation of energy, the energy and temperature dynamic of the BR can be stated. To minimize the use of all kinds of sensors (including both thermal and electrical), a novel regenerative braking power calculation method is proposed, which involves only the voltage of DC traction network and the duty cycle of the chopping circuit; both of them are available for the traction control unit (TCU) of the vehicle. By utilizing a real-time iterative calculation and updating the parameter of the energy model, the operational temperature of the BR can be obtained and monitored in a sensorless manner.

In this study, a sensorless estimation/monitoring method of the operational temperature of BR is proposed. The results show that it is possible to utilize the existing electrical sensors that is mandatory for the traction unit’s operation to estimate the operational temperature of BR, instead of adding dedicated thermal sensors. The results also validate the effectiveness of the proposal is acceptable for the engineering practical.

The proposal of this study provides novel concepts for the sensorless operational temperature monitoring of BR onboard rolling stocks. The proposed method only involves quasi-global electrical variable and the internal control signal within the TCU.

The purpose of this study, thermal radiation and viscous dissipation impacts on double diffusive convection on peristaltic transport of Williamson nanofluid due to induced magnetic field in a tapered channel is examined. The study of propulsion system is on the rise in aerospace research. In spacecraft technology, the propulsion system uses high-temperature heat transmission governed through thermal radiation process. This study will help in assessment of chyme movement in the gastrointestinal tract and also in regulating the intensity of magnetic field of the blood flow during surgery.

The brief mathematical modelling, along with induced magnetic field, of Williamson nanofluid is given. The governing equations are reduced to dimensionless form by using appropriate transformations. Numerical technique is manipulated to solve the highly nonlinear differential equations. The roll of different variables is graphically analyzed in terms of concentration, temperature, volume fraction of nanoparticles, axial-induced magnetic field, magnetic force function, stream functions, pressure rise and pressure gradient.

The key finding from the analysis above can be summed up as follows: the temperature profile decreases and concentration profile increases due to the rising impact of thermal radiation. Brownian motion parameter has a reducing influence on nanoparticle concentration due to massive transfer of nanoparticles from a hot zone to a cool region, which causes a decrease in concentration profile· The pressure rise enhances due to rising values of thermophoresis and thermal Grashof number in retrograde pumping, free pumping and copumping region.

To the best of the authors’ knowledge, a study that integrates double-diffusion convection with thermal radiation, viscous dissipation and induced magnetic field on peristaltic flow of Williamson nanofluid with a channel that is asymmetric has not been carried out so far.

The purpose of this study, 3-aminopyridine, 8-aminoquinoline and some new synthesized 2-aminobenzothiazoles were diazotized with nitrosyl sulfuric acid and subsequently coupled with 5-chloro-8-hydroxy quinoline to synthesize the corresponding heteroarylazo dyes 6–13.

The structures of dyes were characterized by mass, Fourier transform infra red, ¹H proton nuclear magnetic resonance and ultra violet-visible spectroscopic techniques. Absorption spectra of the dyes were measured in acetic acid, ethanol, chloroform, acetonitrile, dimethyl formamide and dimethyl sulfoxide and correlated with the nature of the solvents and substituents. The effects of varying pH on the absorption wavelengths of the azo dyes were also studied. In addition, the acidity constants (pKa) of the dyes were determined using the spectrophotometric method in an ethanol-water mixture (80:20, v/v) at 20–23°C. Besides, density functional theory (DFT) calculations were carried out to compare the energies of proposed azo and hydrazone tautomers of the dyes.

The results showed that the withdrawing chloro groups on the diazo moiety have significant influence (red shift) on the electron absorption spectra of these dyes. In addition, introducing electron withdrawing chloro groups into the benzothiazoles moiety increased the acidic character of dyes.

The synthesized 7-hetroarylazo-5-chloro-8-hydroxy quinoline dyes are new members in the 8-hydroxyquinoline azo dyes family, where very few details regarding the synthesis of such dyes are reported before in the literature. They are unique in terms of synthesis, spectral properties and DFT calculations.

Notable energy losses and voltage deviation issues in low-voltage radial distribution systems are a major concern for power planners and utility companies because of the integration of electric vehicles (EVs). Electric vehicle charging stations (EVCSs) are the key components in the network where the EVs are equipped to energize their battery. The purpose of this paper is coordinating the EVCS and distributed generation (DG) so as to place them optimally using swarm-based elephant herding optimization techniques by considering energy losses, voltage sensitivity and branch current as key indices. The placement and sizing of the EVCS and DG were found in steps.

The IEEE 33-bus test feeder and 52-bus Indian practical radial networks were used as the test system for the network characteristic analysis. To enhance the system performance, the radial network is divided into zones for the placement of charging stations and dispersed generation units. Balanced coordination is discussed with three defined situations for the EVCS and DG.

The proposed analysis shows that DG collaboration with EVCS with suitable size and location in the network improves the performance in terms of stability and losses.

Stability and loss indices are handled with equal weight factor to find the best solution.

The proposed method is coordinating EVCS and DG in the existing system; the EV integration in the low-voltage side can be incorporated suitably. So, it has societal impact.

In this study, the proposed method shows improved results in terms EVCS and DG integration in the system with minimum losses and voltage sensitivity. The results have been compared with another population-based particle swarm optimization method (PSO). There is an improvement of 18% in terms of total power losses and 9% better result in minimum node voltage as compared to the PSO technique. Also, there is an enhancement of 33% in the defined voltage stability index which shows the proficiency of the proposed analysis.

This study aimed to identify the potential for economic activities related to the ocean economy in Brazil to become blue economy (BE) activities, in which the concept of the Sustainable Development Goals (SDGs) is central.

To achieve the aim, the authors collected information on the SDGs and estimated data from the ocean economy sectors for the 256 Brazilian coastal cities. The authors predicted the indices for potential development of territories and sectors in the BE using two parameters: employed persons (EP) and sectoral added value (AV).

The results show that the capitals of coastal states present the highest potential indices for the BE, especially Rio de Janeiro, which accounted for 83.3% of sectoral added value in the Brazilian ocean economy with potential for sustainable development and generated 107,800 active formal jobs (26.9% of the country's total). In addition, restaurants, hotels and similar establishments are, on the Brazilian coast, the most frequent on the coastal zone and have the highest potential for BE activities.

Regarding its contributions, this research innovates by developing an indicator that can help stakeholders understand the similarities and differences between cities and regions, whether through a social, economic, or environmental lens. Therefore, by following this methodological path for measuring the BE, viewing the distinct patterns of sustainable development by area is possible, thereby supporting action plans for the fulfillment of the 2030 Agenda and the implementation of a marine spatial planning process for the country in the context of the Ocean Decade (2021–2030).

The peer review history for this article is available at: https://publons.com/publon/10.1108/IJSE-02-2023-0112

The purpose of this study is to identify the main perspectives and trends in educational data mining (EDM) in the e-learning environment from a managerial perspective.

This paper proposes a systematic literature review to identify the main perspectives and trends in EDM in the e-learning environment from a managerial perspective. The study domain of this review is restricted by the educational concepts of e-learning and management. The search for bibliographic material considered articles published in journals and papers published in conferences from 1994 to 2023, totaling 30 years of research in EDM.

From this review, it was observed that managers have been concerned about the effectiveness of the platform used by students as it contains the entire learning process and all the interactions performed, which enable the generation of information. From the data collected on these platforms, there are improvements and inferences that can be made about the actions of educators and human tutors (or automatic tutoring systems), curricular optimization or changes related to course content, proposal of evaluation criteria and also increase the understanding of different learning styles.

This review was conducted from the perspective of the manager, who is responsible for the direction of an institution of higher education, to assist the administration in creating strategies for the use of data mining to improve the learning process. To the best of the authors’ knowledge, this review is original because other contributions do not focus on the manager.

This paper aims at studying numerically the entropy generation of nanofluid flowing over an inclined sheet in the presence of external magnetic field, heat source/sink, chemical reaction along with slip boundary conditions imposed on an impermeable wall.

A suitable similarity transformation technique has been used to convert the coupled nonlinear partial differential equations to ordinary differential equations (ODEs). The ODEs are then solved simultaneously using the finite difference method implemented through an in-house computer program. The effects of different controlling parameters such as magnetic parameter, radiation parameter, Brownian motion parameter, thermophoresis parameter, chemical reaction parameter, Reynolds number, Brinkmann number, Prandtl number, velocity slip parameter, temperature slip parameter and the concentration slip parameter on the entropy generation and Bejan number have been discussed comprehensively through the relevant physical insights for the first time.

The relative strengths of the irreversibilities due to heat transfer, fluid friction and the mass diffusion arising due to the change in each of the controlling variables have been delineated both in the near-wall and far-away-wall regions, which may be helpful for a better understanding of the thermo-fluid dynamics of nanofluid in boundary layer flows. The numerical results obtained from the present study have also been validated with results published in open literature.

The effects of different controlling parameters such as magnetic parameter, radiation parameter, Brownian motion parameter, thermophoresis parameter, chemical reaction parameter, Reynolds number, Brinkmann number, Prandtl number, velocity slip parameter, temperature slip parameter and the concentration slip parameter on the entropy generation and Bejan number have been discussed comprehensively through the relevant physical insights for the first time.

The purpose of this paper was identification and empirical assessment of the differentiation of consumers' attitudes in Ukraine and Poland to Russian brands and other brands offered on the Russian market after Russia’s aggression against Ukraine on February 24, 2022.

The main research methods include a systematic literature review and the authors' own surveys conducted in November 2022. The research sample comprised 950 consumers – 67% of them were Poles, 30% – Ukrainians and 3% from other countries.

A respondents' country (Poland and Ukraine) does not impact attitudes to brands offered on the Russian market after Russia's invasion of Ukraine on February 24, 2022. Moreover, it does not affect and differentiate emotional engagement in the conflict and assistance to war victims. Cluster analysis resulted in identifying two groups on the basis of consumers' declared emotional reactions to the war. The first group was smaller (N = 353, 37.2%), referred to as “indifferent consumers”, and was characterized by a greater inclination to purchase brands offered in Russia. The other cluster, referred to as “sensitive consumers” (N = 597, 62.8%), comprises those engaged in offering assistance to war victims, showing strong emotions in connection with the aggression and military activities and characterized by a clearly negative attitude to Russian and other offered brands and an inclination to boycott these brands.

A short time horizon, the study confined to two countries, difficulties in reaching Ukrainian respondents due to power failures in Ukraine in the period of conducting the survey (November 2022), a non-representative research sample – overrepresentation of people aged 18–25 years.

The research study contributes to the knowledge about consumer brand attitudes and preferences under unique social, economic and market conditions. These conditions were created by Russia's invasion of Ukraine in 2022, as well as the international and global character of the war in Ukraine. The significant implications of the study refer to brand communication policies and companies' CSR-related declarations. A number of consumers' errors were recorded, resulting from wrong brand retrieval, which were rectified at a later stage as a result of international restrictions imposed on Russia, harsh media criticism and social international embargoes imposed on brands offered in Russia. The marketing communication of contemporary global brands should give consideration to the informative function of CSR activities, and the communication process should be continuous. Critical attitudes and an inclination to boycott brands point to the possible consequences faced by inconsistent and ethically doubtful brand policies. This implication is clearly confirmed by the results of the study.

The authors also wish to highlight the implications for practice and society. As mentioned earlier, Polish consumers involved in providing aid to victims of the war also expressed their opposition to the war by boycotting Russian products and international brands remaining in Russia. Popularization of the research results obtained by the authors can be a form of sensitizing the public to the need for long-term relief, awakening global awareness of the essence and importance of sanctions imposed on Russia, as well as the possibility of expressing opposition through individual purchasing decisions and boycotting brands still present in Russia.

The study allowed for identifying consumers' differentiated brand attitudes in two countries: a country inflicted by war (Ukraine) and a front-line country, strongly supporting Ukraine (Poland). The research contributes to consumer behavior theories and studies of consumer attitudes and preferences from the perspective of international corporations' CSR activities under the unique conditions of war. Also, it contributes to the knowledge of the mechanism of forming attitudes to Russian and international brands offered in Russia among CEE consumers.

The objective was to evaluate the effect of banana peel into cake (a bakery product that may add bananas) and panettone (a product that never is added to bananas) formulations on consumers' acceptance and perceived attributes and the effect on the technological properties of the product.

Bakery products were produced with banana peel in the formulation and control samples without residue. Volunteers scored their acceptance and checked all attributes applied to the four samples in the blind and informed tests. The texture, color, proximate composition and bake properties were measured.

The acceptance of both cakes, with and without banana peel, was not affected when consumers were informed that there was a residue in both cakes. Relative risk indicated that information had no influence on acceptance. Panettone with banana pulp showed a reduction in acceptance when volunteers were informed of the presence of banana peel. Risk analysis showed a significant relative risk of product rejection when consumers were aware of information. The addition of banana peel enhanced panettone chewiness and crumb hardness, reduced bake loss of cakes, reduced the volume of both products and changed some color parameters of both products.

Banana peel is a source of functional compounds, but it is not clear how consumers react when informed that the food presents it.

The purpose of this paper is to study haemodynamic flow characteristics and entropy analysis in a bifurcated artery system subjected to stenosis, magnetohydrodynamic (MHD) flow and aneurysm conditions. The findings of this study offer significant insights into the intricate interplay encompassing electro-osmosis, MHD flow, microorganisms, Joule heating and the ternary hybrid nanofluid.

The governing equations are first non-dimensionalised, and subsequently, a coordinate transformation is used to regularise the irregular boundaries. The discretisation of the governing equations is accomplished by using the Crank–Nicolson scheme. Furthermore, the tri-diagonal matrix algorithm is applied to solve the resulting matrix arising from the discretisation.

The investigation reveals that the velocity profile experiences enhancement with an increase in the Debye–Hückel parameter, whereas the magnetic field parameter exhibits the opposite effect, reducing the velocity profile. A comparative study demonstrates the velocity distribution in Au-CuO hybrid nanofluid and Au-CuO-GO ternary hybrid nanofluid. The results indicate a notable enhancement in velocity for the ternary hybrid nanofluid compared to the hybrid nanofluids. Moreover, an increase in the Brinkmann number results in an augmentation in entropy generation.

This study investigates the flow characteristics and entropy analysis in a bifurcated artery system subjected to stenosis, MHD flow and aneurysm conditions. The governing equations are non-dimensionalised, and a coordinate transformation is applied to regularise the irregular boundaries. The Crank–Nicolson scheme is used to model blood flow in the presence of a ternary hybrid nanofluid (Au-CuO-GO/blood) within the arterial domain. The findings shed light on the complex interactions involving stenosis, MHD flow, aneurysms, Joule heating and the ternary hybrid nanofluid. The results indicate a decrease in the wall shear stress (WSS) profile with increasing stenosis size. The MHD effects are observed to influence the velocity distribution, as the velocity profile exhibits a declining nature with an increase in the Hartmann number. In addition, entropy generation increases with an enhancement in the Brinkmann number. This research contributes to understanding fluid dynamics and heat transfer mechanisms in bifurcated arteries, providing valuable insights for diagnosing and treating cardiovascular diseases.