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The purpose of this paper is to analyze two different approaches (Models A and B) for an adiabatic boundary condition at the wall of a channel filled with a porous medium. The analytical solutions for the velocity distribution, the fluid and solid phase temperature distributions are derived and compared with numerical solutions. The phenomenon of heat flux bifurcation for Model A is demonstrated. The effects of pertinent parameter C on the applicability of the Models A and B are discussed. Analytical solutions for the overall Nusselt number and the heat flux distribution at the channel wall are derived and the influence of pertinent parameters Da and k on the overall Nusselt number and the heat flux distribution is discussed.

Two approaches (Models A and B) for an adiabatic boundary condition in porous media under local thermal non-equilibrium (LTNE) conditions are analyzed in this work. The analysis is applied to a microchannel which is modeled as a porous medium.

The phenomenon of heat flux bifurcation at the wall for Model A is demonstrated. The effect of pertinent parameter C on the applicability of each model is discussed. Model A is applicable when C is relatively large and Model B is applicable when C is small. The heat flux distribution is obtained and the influence of Da and k is discussed. For Model A, ϕ_Afin increases and ϕ_Asub, ϕ_Acover decrease as Da decreases and k is held constant, ϕ_Asub increases and ϕ_Afin, ϕ_Acover decrease as k increases while Da is held constant; for Model B, ϕ_Bfin increases and ϕ_Bsub decreases either as Da decreases or k decreases. The overall Nusselt number is also obtained and the effect of Da and k is discussed: Nu increases as either Da or k decrease for both models. The overall Nusselt number for Model A is larger than that for Model B when Da is large, the overall Nusselt numbers for Models A and B are equivalent when Da is small.

Proper representation of the energy equation and the boundary conditions for heat transfer in porous media is very important. There are two different models for representing energy transfer in porous media: local thermal equilibrium (LTE) and LTNE. Although LTE model is more convenient to use, the LTE assumption is not valid when a substantial temperature difference exists between the solid and fluid phases.

Fluid flow and convective heat transfer in porous media have many important applications such as thermal energy storage, nuclear waste repository, electronic cooling, geothermal energy extraction, petroleum processing and heat transfer enhancement.

This work has important fundamental implications.

In this work the microchannel is modeled as an equivalent porous medium. The analytical solutions for the velocity distribution, the fluid and solid phase temperature distributions are obtained and compared with numerical solutions. The first type of heat flux bifurcation phenomenon, which indicates that the direction of the temperature gradient for the fluid and solid phases is different at the channel wall, occurs when Model A is utilized. The effect of pertinent parameter C on the applicability of the models is also discussed. The analytical solutions for the overall Nusselt number and the heat flux distribution at the channel wall are derived, and the effects of pertinent parameters Da and k on the overall Nusselt number and the heat flux distribution are discussed.

The purpose of this paper is to evaluate the impact of minority shareholders’ attendance at shareholders meetings on related party transaction (RPT) proposals.

This paper empirically examines the impact of minority shareholders’ attendance in shareholders’ meetings on the voting results of RPT proposals based on the hand-collected voting data of Chinese listed companies.

The empirical result shows a significant positive relationship between the attendance of minority shareholders and the nonagreeable vote rate of RPT proposals. Moreover, this positive relationship is strengthened when the corporate governance is poor, the negative media coverage is high, and the on-site attendance of minority shareholders is high. Conversely, good corporate governance and high positive media coverage can weaken this positive correlation. The additional analysis reveals that the number of RPTs and better market performance in the future can be significantly reduced when minority shareholders express their nonagreeable voice actively.

This paper analytically and empirically examines the impact of minority shareholders’ attendance in shareholders’ meetings on the voting results of RPT proposals based on the hand-collected voting data of Chinese listed companies. It provides direct and convincing evidence for the impact of minority shareholders’ attendance and exercise of voting rights in shareholders’ meetings on the outcome of RPT proposals. It complements the literature on the governance effects of minority shareholders’ attendance in shareholders’ meetings to exercise their voting rights in emerging capital markets. This study has practical value by guiding minority investors to participate actively in corporate governance.

Power‐electronic systems have been playing a significant role in the integration of large‐scale wind turbines into power systems due to the fact that during the past three decades power‐electronic technology has experienced a dramatic evolution. This second part of the paper aims to focus on a comprehensive survey of power converters and their associated control systems for high‐power wind energy generation applications.

Advanced control strategies, i.e. field‐oriented vector control and direct power control, are initially reviewed for wind‐turbine driven doubly fed induction generator (DFIG) systems. Various topologies of power converters, comprising back‐to‐back (BTB) connected two‐ and multi‐level voltage source converters (VSCs), BTB current source converters (CSCs) and matrix converters, are identified for high‐power wind‐turbine driven PMSG systems, with their respective features and challenges outlined. Finally, several control issues, viz., basic control targets, active damping control and sensorless control schemes, are elaborated for the machine‐ and grid‐side converters of PMSG wind generation systems.

For high‐power PMSG‐based wind turbines ranging from 3 MW to 5 MW, parallel‐connected 2‐level LV BTB VSCs are the most cost‐effective converter topology with mature commercial products, particularly for dual 3‐phase stator‐winding PMSG generation systems. For higher‐capacity wind‐turbine driven PMSGs rated from 5 MW to 10 MW, medium voltage multi‐level converters, such as 5‐level regenerative CHB, 3‐ and 4‐level FC BTB VSC, and 3‐level BTB VSC, are preferred. Among them, 3‐level BTB NPC topology is the favorite with well‐proven technology and industrial applications, which can also be extensively applicable with open‐end winding and dual stator‐winding PMSGs so as to create even higher voltage/power wind generation systems. Sensorless control algorithms based on fundamental voltages/currents are suggested to be employed in the basic VC/DPC schemes for enhancing the robustness in the entire PMSG‐based wind power generation system, due to that the problems related with electromagnetic interferences in the position signals and the failures in the mechanical encoders can be avoided.

This second part of the paper for the first time systematically reviews the latest state of arts with regard to power converters and their associated advanced control strategies for high‐power wind energy generation applications. It summarizes a variety of converter topologies with pros and cons highlighted for different power ratings of wind turbines.

Wind energy has matured to a level of development at which it is ready to become a generally accepted power generation technology. The aim of this paper is to provide a brief review of the state of the art in the area of electrical machines and power‐electronic systems for high‐power wind energy generation applications. As the first part of this paper, latest market penetration, current technology and advanced electrical machines are addressed.

After a short description of the latest market penetration of wind turbines with various topologies globally by the end of 2010 is provided, current wind power technology, including a variety of fixed‐ and variable‐speed (in particular with doubly‐fed induction generator (DFIG) and permanent magnet synchronous generator (PMSG) supplied with partial‐ and full‐power converters, respectively) wind power generation systems, and modern grid codes, is presented. Finally, four advanced electrical‐machine systems, viz., brushless DFIG, open winding PMSG, dual/multi 3‐phase stator‐winding PMSG and magnetic‐gear outer‐rotor PMSG, are identified with their respective merits and challenges for future high‐power wind energy applications.

For the time being, the gear‐drive DFIG‐based wind turbine is significantly dominating the markets despite its defect caused by mechanical gears, slip rings and brush sets. Meanwhile, direct‐drive synchronous generator, especially utilizing permanent magnets on its rotor, supplied with a full‐capacity power converter has become a more effective solution, particularly in high‐power offshore wind farm applications.

This first part of the paper reviews the latest market penetration of wind turbines with a variety of mature topologies, by summarizing their advantages and disadvantages. Four advanced electrical‐machine systems are selected and identified by distinguishing their respective merits and challenges for future high‐power wind energy applications.

This study developed a theoretical model to test the relationship between digital capability and Industry 4.0 (I4.0) and its effect on innovation performance in small and medium-sized enterprises (SMEs).

The proposed theoretical model was evaluated using partial least-squares structural equation modeling and fuzzy-set qualitative comparative analysis. The data were obtained from a sample of 536 SMEs in Chile.

The proposed model presented two dimensions of digital capability: management and information and communication technologies (ICTs). Management models composed of enterprise resource planning and customer relationship management systems are essential for optimizing organizational management. Meanwhile, ICTs facilitate the smooth flow of information within an organization, leading to improved efficiency in production processes. I4.0 is encouraged by exposing SMEs to base technologies such as data analytics. These results confirm that I4.0 influences innovation performance.

SME managers should encourage the development of digital capabilities to transition toward I4.0, as this can make SMEs more competitive and innovative in changing and dynamic scenarios.

I4.0 adoption and the development of digital capabilities can directly affect employment and national economic growth.

Most studies focus on the organizational factors affecting SMEs’ I4.0 adoption. They do not, however, address the role played by current digital capability in I4.0 technology adoption and its effect on firms’ innovation performance.

Este estudio desarrolló un modelo teórico para probar la relación entre la capacidad digital y la Industria 4.0 (I4.0) y su efecto en el desempeño de la innovación en pequeñas y medianas empresas (PYME).

El modelo teórico propuesto se evaluó mediante el uso de modelos de ecuaciones estructurales de mínimos cuadrados parciales y análisis comparativo cualitativo de conjuntos difusos. Los datos se obtuvieron de una muestra de 536 pymes de Chile.

El modelo propuesto presenta dos dimensiones de la capacidad digital: la gestión y las tecnologías de la información y la comunicación (TIC). Los modelos de gestión compuestos por sistemas de planificación de recursos empresariales y de gestión de relaciones con los clientes son esenciales para optimizar la gestión organizacional. Por su parte, las TIC facilitan el flujo fluido de información dentro de una organización, lo que conduce a una mejora de la eficiencia en los procesos de producción. La I4.0 se fomenta exponiendo a las PYME a tecnologías de base como el análisis de datos. Estos resultados confirman que la I4.0 influye en el rendimiento de la innovación.

La mayoría de los estudios se centran en los factores organizativos que afectan a la adopción de la I4.0 por parte de las pymes, pero no abordan el papel que desempeña la capacidad digital actual en la adopción de la tecnología I4.0 y su efecto en el desempeño innovador de las empresas.

Los gestores de las PYMES deben incentivar el desarrollo de capacidades digitales para realizar la transición hacia la I4.0, ya que esto puede hacer que las PYMES sean más competitivas e innovadoras en escenarios cambiantes y dinámicos.

La adopción de la I4.0 y el desarrollo de capacidades digitales pueden afectar directamente al empleo y al crecimiento económico nacional.

This study aims to identify mutually exclusive risk categories and determine whether these categories effectively capture the potential impact of risk disclosures on the initial returns of initial public offerings (IPOs) in the financial and non-financial sectors.

Data were collected from 131 Indian IPO prospectuses (104 non-financial and 27 financial) issued between 2015 and 2021. Content analysis was performed to identify mutually exclusive risk categories, and the effects of these categories on initial IPO returns were assessed by regression analysis

The findings revealed that risk factor disclosures have a significant impact on underpricing, but not all risk factors are relevant. In the current study, in the financial sector, IPO underpricing was mostly driven by technological and competitive risk factors. In the non-financial sector, underpricing was predominantly influenced by operating risk and compliance risk factors.

The limitations of this study include the use of sentence-based context analysis, which does not assess the quality of risk disclosures. The statistical data reduction technique used to generate mutually exclusive risk categories may also be a limitation.

This research has the potential to assist companies in standardizing the disclosure of risks within IPO prospectuses. The insights gained can inform market regulators in designing policies aimed at aiding investors in formulating investment strategies, ultimately enhancing transparency and clarity regarding information disclosure. Moreover, the findings offer valuable guidance to investors in selecting IPOs aligned with their risk tolerance levels.

From a societal perspective, this study represents advancements by guiding regulators towards developing and regulating standardized, mutually exclusive risk factors. Such measures can aid investors in enhancing their decision-making perspectives regarding IPOs, promoting a more informed and confident investment environment.

This study is a pioneering attempt to address knowledge gaps by identifying distinct categories of risk disclosures in IPO prospectuses and examining their potential influence on IPO underpricing in the financial and non-financial sectors in India.