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The purpose of this paper is to present a family of robust metasurface-oriented wireless power transfer systems with improved efficiency and size compactness. The effect of geometric and structural features on the overall efficiency and miniaturisation is elaborately studied, while the presence of substrate losses is, also, considered. Moreover, to further enhance the performance, possible means for reducing the operating frequency, without comprising the unit-cell size, are proposed.

The key element of the design technique is the edge-coupled split-ring resonators patterned in various metasurface configurations and optimally placed to increase the total efficiency. To this goal, a rigorous three-dimensional algorithm, launching a new high-order prism macroelement, is developed in this paper for the fast evaluation of the required quantities. The featured scheme can host diverse approximation orders, while it is drastically more economical than existing methods. Hence, the demanding wireless power transfer systems are precisely modelled via reduced degrees of freedom, without the need to conduct large-scale simulations.

Numerical results, compared with measured data from fabricated prototypes, validate the design methodology and prove its competence to provide enhanced metasurface wireless power transfer systems. An assortment of optimized 3 x 3 and 5 x 5 metamaterial setups is investigated, and interesting deductions, regarding the impact of the inter-element gaps, the distance between the transmitting and receiving components and the substrate losses, are derived. Also, the proposed vector macroelement technique overwhelms typical implementations in terms of computational burden, particularly when combined with the relevant commercial software packages.

Systematic design of advanced real-world wireless power transfer structures through optimally selected metasurfaces with fully controllable electromagnetic properties is presented. The analysis is performed by means of a rapid prism macroelement methodology, which leads to very confined meshes, accurate results and significantly reduced overhead. The selected metamaterial resonators are found to be very flexible and reconfigurable, even in the case of large substrate conductivity losses, whereas their contribution to the system’s total efficiency is decisive.

For smooth running of business affairs, there needs to be a coordination among manufacturer, collector and retailer in forward and reverse supply chain. This paper handles the problem of making pricing, collecting and percentage sharing decisions in a closed-loop supply chain. The purpose of this paper is to examine the effect of responsibility sharing percentage on the profits of a manufacturer, a retailer and a collector. The paper further aims to understand the mutual interactions among decision variables and profit functions. It also determines the optimal selling price, optimal time, wholesale price, sharing percentage and optimal return rate in such a manner that the profit function is maximized.

The authors presented a three-echelon model consisting of a manufacturer, a retailer and a collector in the closed-loop supply chain and optimized the profits of each supply chain member. The authors introduced SRR models for the remanufacturing by providing some percentage of physical and financial support to the collector. Optimization techniques have been applied to obtain optimal solutions. Numerical examples and graphical representations of the optimal solutions are provided to illustrate the model.

This study stresses on profitable value retrieval from returned products, and it discusses how responsibility sharing can improve profitability and reduce the workload of an individual. In total, three main results are found. First, sharing and coordination among chain members can improve collector’s profit. Second, supply chain performance may also improve over time. Third, the profit of each member of the supply chain increases with an increase in sharing percentage up to a certain limit. So, the manufacturer can share the responsibility of the collector under a fixed limit.

The main limitation of this model is that there is no difference between manufactured and remanufactured products. There are many correlated issues that need to be further investigated. The future study in this direction may include multi-retailer, stochastic demand patterns.

It is directly utilized by supply chain industries in which coordination among chain members is still needed to maximize profits. This information enables the manufacturer to assist the collector financially or physically for the proper management of the three-layer supply chain. The present work will form a guideline to choose the appropriate parameter(s) and mathematical technique(s) in different situations for remanufacturable products.

From the management point of view, this study delivers the strongest result to remanufacturing companies and for whom effective and efficient coordination among chain members is vital to the overall performance of the supply chain.

There are very few studies that consider the remanufacturing of used products under a fixed time period. The authors considered selling price-sensitive and time-dependent exponentially declining demand. This model is developed by considering all possible help to a collector from manufacturer to collect used products from consumers. This research complements past research by showing coordination among supply chain members within a fixed time horizon.

This paper aims to focus on research work related to metamaterial-based sensors for material characterization that have been developed for past ten years. A decade of research on metamaterial for sensing application has led to the advancement of compact and improved sensors.

In this study, relevant research papers on metamaterial sensors for material characterization published in reputed journals during the period 2007-2018 were reviewed, particularly focusing on shape, size and nature of materials characterized. Each sensor with its design and performance parameters have been summarized and discussed here.

As metamaterial structures are excited by electromagnetic wave interaction, sensing application throughout electromagnetic spectrum is possible. Recent advancement in fabrication techniques and improvement in metamaterial structures have led to the development of compact, label free and reversible sensors with high sensitivity.

The paper provides useful information on the development of metamaterial sensors for material characterization.

This paper aims to study companies’ strategic responses to regulative institutional pressures on sustainability reporting. Particularly, it investigates the role of multiple stakeholder demands in shaping corporate responses to Law 11/2018 that transposes the EU Non-Financial Reporting Directive in Spain.

Informed by Oliver’s framework, the study analyzes the 2018 non-financial information of Spanish listed companies mandated to report under Law 11/2018 to explore the relationship between adopting a particular strategic response and companies’ stakeholder configuration.

Companies facing multiple stakeholder pressures tend to use a compromise strategy favoring the disclosure of relevant topics to a specific stakeholder type. Specifically, environmentalists are the most influential stakeholder in determining the coverage of sustainability topics to the detriment of other stakeholders when companies suffer from regulatory pressures.

The study contributes to disentangling the factors determining how companies respond to sustainability reporting regulation. Future research could perform longitudinal and large multinational analyses to study the evolutionary process of corporate responses.

The study is relevant to managers and policymakers as it highlights that sustainability reporting regulation should promote the coverage of relevant topics to less influential stakeholders.

The study explores the extent to which current sustainability reporting regulation can increase transparency on sustainability issues for all stakeholders.

In contrast to previous literature exploring the extent to which firms comply with regulation, the study considers that companies can respond more actively to mandatory sustainability reporting requirements.

Due to high speeds, heavy loads, large slide-to-roll ratios (SRR) and other variable operating conditions, some rolling bearings that have been working in harsh conditions may experience flash temperatures in the contact area, which may result in early damage like smearing and then affect service life. This study aims to investigate the flash temperature phenomenon of rolling bearings through theoretical and experimental analysis.

A technology for measuring temperature distribution in rolling ball on disk contact under lubrication was developed. The test-rig can simulate the ball bearing contact. The effects of working conditions such as entrainment speed, load, SRR and lubricating oil viscosity on the flash temperature were investigated.

The results of the theoretical calculation and experiments indicate that the parameters promoting the reduction of film thickness in elastohydrodynamic lubrication are always related with the number of flash points, even film thickness reduced to mixed lubrication. The flash temperature is easier to happen in conditions of high SRR, heavy load, slow entrainment speed and low viscosity oil.

This work conducts an experimental study on the flash temperature phenomenon, providing a test technology for bearing lubrication and failure investigation.

This author has opted into Transparent Peer Review available at: https://publons.com/publon/10.1108/ILT-04-2023-0104

Owing to the importance of the efficiency of commercial banks, the aim of this paper is to find the relationship between capital regulation, monetary policy and the asymmetric effects of the commercial banks' efficiency.

First, the paper makes a static profit model of commercial banks with double constraints and then makes a proposition with numeric simulation.

In this paper, the author finds it unreasonable to calculate the commercial banks' cost and profit efficiency by SFA (DEA) directly, as there is no evidence that indicates the linearity relationship among them. Hence, more complicated solutions should be introduced.

The rate of non‐performing loans (NPL) is inversely proportional to the commercial banks' cost and profit efficiency and capital adequacy ratio (CAR) and statutory reserve ratio (SRR) show a nonlinear relationship between commercial banks' cost and profit efficiency. Hence, the paper defines the different influences of commercial banks' efficiency imposed by CAR and SRR as the asymmetric effects of commercial banks' efficiency.

The nonlinear relationship is found based on improved Kopecky and VanHoose, so excessive regulation has harmful effects on the commercial banks. The reasonable capital regulation and other prudential supervision measures should be emphasized.

First, the paper gets its proposition through the improved KV model, which displays a new perception on analyzing this problem. Second, the nonlinear relationship is discovered by this new model and the empirical results show the nonlinear relationship further.

Managerial decision-making is an area of interest to both academia and practitioners. Researchers found that managers often fail to manage complex decision-making tasks and system thinkers assert that generic structures known as systems archetypes help them to a great deal in handling such situations. In this paper, it is demonstrated that decision makers resort to lowering of goal (quick-fix) in order to resolve the gap between the goal and current reality in the “drifting the goals” systems archetype.

A real-life case study is taken up to highlight the pitfalls of “drifting the goals” systems archetype for a decision situation in the Indian two-wheeler industry. System dynamics modeling is made use of to obtain the results.

The decision makers fail to realize the pitfall of lowering the goal to resolve the gap between the goal and current reality. It is seen that, irrespective of current less-than-desirable performance, managers adopting corrective actions other than lowering of goals perform better in the long run. Further, it is demonstrated that extending the boundary and experimentation results in designing a better service system and setting benchmarks.

The best possible way to avoid the pitfall is to hold the vision and not lower the long term goal. The managers must be aware of the pitfalls beforehand.

Systems thinking is important in complex decision-making tasks. Managers need to embrace long-term perspective in decision-making. This paper demonstrates the value of systems thinking in terms of a case study on the “drifting the goals” systems archetype.

This paper aims to concentrate on research that has been conducted in the previous decade on metamaterial (MTM)-based sensors for material characterization, which includes solid dielectrics, micro fluids and biomolecules.

There has been a vast advancement in sensors based on MTM since the past few decades. MTM elements provide a sensitive response to materials while having a tiny footprint, making them an appealing alternative for realizing diverse sensing devices.

Related research papers on MTM sensors published in reputable journals were reviewed in this report, with a specific emphasis on the structure, size and nature of the materials characterized. Because electromagnetic wave interaction excites MTM structures, sensing applications around the electromagnetic spectrum are possible.

The paper contains valuable information on MTM sensor technology for material characterization, and this study also highlights the challenges and approaches that will guide future development.

Wireless power transfer (WPT) is deemed as an emerging technology with exciting applications, like wireless charging devices, and electric vehicles, whereas metamaterials exhibit exceptional properties. For every WPT system that occupies coupled magnetic resonances, it is also mandatory to involve resonators. The purpose of this paper is to introduce a new interdigitated split-ring resonator (I-SRR) as the basic part of a WPT system, pursuing advanced levels of efficiency.

A novel WPT system, which exploits I-SRRs as its elementary blocks, is comprehensively examined. The analysis investigates the distance between the modules, the distance between transmitting and receiving components as well as the geometrical features of the structure. Several numerical data derived via the finite element method unveil the merits of the featured configuration.

The proposed arrangement reveals a noteworthy enhancement of the power delivered to the load and a promising tuning of the operational frequency via the interdigitated topology. Several parametric studies clarify the principal characteristics of the proposed setup, facilitating the design of high-end systems. In particular, the distance between the resonators and the port loops affect the matching of the input and output ports, allowing optimisation of power efficiency, while the length of the I-SRR gap can determine the operational frequency.

Development of a WPT system, which utilises I-SRRs as its key elements. Incorporation of metamaterials into WPT technology. Efficiency enhancement of WPT systems and alternative design via geometrical modifications. The necessity of lumped elements to implement the WPT resonators is eliminated by utilising split-ring resonators components, enabling compactness in several implementations.

This study aims to evaluate the rheological properties of aviation lubricating oil under conditions of heavy load, high speed and high temperature and the applicability of the classical rheological model under severe conditions.

A Chinese aviation lubricating oil was used and its traction curves were obtained using a new two-disk tribotester. Its rheological parameters were calculated based on empirical formulae. Moreover, the traction force was calculated based on the classical Eyring rheological model.

The traction curves are obtained with respect to contact pressure, temperature and rolling speed. The rheological parameters are significantly influenced by environmental factors, especially viscosity. The traction force calculated using the Eyring model is consistent with the experimental results.

A novel two-disk tribotester was designed using a gas bearing and speed–force closed-loop control to ensure measurement accuracy. The mechanism of rheological properties was analyzed and the applicability of the classical rheological model under severe conditions was verified. It provided an experimental and theoretical basis for expanding the application of classical rheological models under extreme conditions.