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The purpose of this paper is to control flow separation over a NACA 4415 airfoil by applying unsteady forces to the separated shear layers using dielectric barrier discharge (DBD) plasma actuators. This novel flow control method is studied under conditions which the airfoil angle of attack is 18°, and Reynolds number based on chord length is 5.5 × 10⁵.

Large eddy simulation of the turbulent flow is used to capture vortical structures through the airfoil wake. Power spectral density analysis of the baseline flow indicates dominant natural frequencies associated with “shear layer mode” and “wake mode.” The wake mode frequency is used simultaneously to excite separated shear layers at both the upper surface and the trailing edge of the airfoil (dual-position excitation), and it is also used singly to excite the upper surface shear layer (single-position excitation).

Based on the results, actuations manipulate the shear layers instabilities and change the wake patterns considerably. It is revealed that in the single-position excitation case, the vortices shed from the upper surface shear layer are more coherent than the dual-position excitation case. The maximum value of lift coefficient and lift-to-drag ratio is achieved, respectively, by single-position excitation as well as dual-position excitation.

The paper contributes to the understanding and progress of DBD plasma actuators for flow control applications. Further, this research could be a beneficial solution for the promising design of advanced low speed flying vehicles.

This study aims to price the risk contribution of general Takaful at the level of tariff cells, considering a spatial dependency framework.

Three different models, including a generalized linear model, a generalized linear mixed model (GLMM) and a spatial generalized linear mixed model (SGLMM), according to the actuarial modeling of general Takaful, are used to price pure risk contribution (PRC).

The results reveal that the SGLMM yields more accurate predictions of the PRC compared to the other models, emphasizing the significance of spatial modeling in this context. Following the estimation of the PRC, the gross contribution according to the mechanism of Takaful models is calculated considering the spatial model.

Considering the similarities between Takaful and insurance, this study addresses the pricing of general Takaful within different Takaful models through a spatial dependency framework, such that the practical implications of the study are applicable for running Takaful's business in both Islamic and non-Islamic countries.

Most studies consider only the social or practical view of Takaful. This study contributes to the broader knowledge and understanding of Takaful by presenting a conceptual understanding of Takaful and then investigates the practical application of pricing risk contribution using innovative modeling of claim frequency and severity at the level of tariff cells.

This paper aims to minimize the total carbon emissions and costs and also maximize the total social benefits.

The present study develops a mathematical model for a closed-loop supply chain network of perishable products so that considers the vital aspects of sustainability across the life cycle of the supply chain network. To evaluate carbon emissions, two different regulating policies are studied.

According to the obtained results, increasing the lifetime of the perishable products improves the incorporated objective function (IOF) in both the carbon cap-and-trade model and the model with a strict cap on carbon emission while the solving time increases in both models. Moreover, the computational efficiency of the carbon cap-and-trade model is higher than that of the model with a strict cap, but its value of the IOF is worse. Results indicate that efficient policies for carbon management will support planners to achieve sustainability in a cost-effectively manner.

This research proposes a mathematical model for the sustainable closed-loop supply chain of perishable products that applies the significant aspects of sustainability across the life cycle of the supply chain network. Regional economic value, regional development, unemployment rate and the number of job opportunities created in the regions are considered as the social dimension.

In today’s era, a country’s economy and society are continuously improved by entrepreneurship that utilizes digital technology. The current study, conducted among university students in Pakistan, examines the roles of digital aspects in moving toward digital innovation (DI) and digital entrepreneurship (DE).

The study is based on quantitative and cross-sectional data. A survey questionnaire was used to obtain responses from respondents recruited through the convenience sampling technique.

The results from structural equation modeling (SEM) analysis suggest significant effects of technology orientation (TO), entrepreneurial orientation (EO), and DI on DE. The impact of DI on DE is also significant. On the other hand, digital technology self-efficacy (DTSE) is not found to be a significant predictor of DI and DE. Moreover, DI is found to be a significant mediator, which mediates the relationships of TO and EO with DE. On the contrary, DI did not mediate the significant relationship between DTSE and DE.

The study’s findings would benefit policymakers and planners in developing policies to encourage the usage of digital technologies to provide solutions in entrepreneurship. The findings also support promoting DE to tackle business challenges and achieve organizational and academic goals.

The study emphasizes the roles of digital technology, innovation, and entrepreneurship in a developing context.