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Endwall film cooling protects vane endwall by coolant coverage, especially at the leading edge (LE) region and vane-pressure side (PS) junction region. Strong flow impingement and complex vortexaa structures on the vane endwall cause difficulties for coolant flows to cover properly. This work aims at a full-scale arrangement of film cooling holes on the endwall which improves coolant efficiency in the LE region and vane-PS junction region.

The endwall film holes are grouped in four-holes constructal patterns. Three ways of arranging the groups are studied: based on the pressure field, the streamlines or the heat transfer field. The computational analysis is done with the k-ω SST model after validating the turbulence model properly.

By clustering the film cooling holes in four-holes patterns, the ejection of the coolant flow is stronger. The four-holes constructal patterns also improve the local coolant coverage in the “tough” regions, such as the junction region of the PS and the endwall. The arrangement based on streamlines distribution can effectively improve the coolant coverage and the arrangement based on the heat transfer distribution (HTD) has benefits by reducing high-temperature regions on the endwall.

A full-scale endwall film cooling design is presented considering interactions of different film cooling holes. A comprehensive model validation and mesh independence study are provided. The cooling holes pattern on the endwall is designed as four-holes constructal patterns combined with several arrangement choices, i.e. by pressure, by heat transfer and by streamline distributions.

This paper investigates the challenges and opportunities for the deployment of whistleblowing as an accountability mechanism to curb corruption and fraud in a developing country. Nigeria is the institutional setting for the study.

Adopting an institutional theory perspective and a survey protocol of urban residents in the country, the study presents evidence on the whistleblowing program introduced in 2016. Nigeria’s whistleblowing initiative targets all types of corruption, including corporate fraud.

This study finds that, even in the context of a developing country, whistleblowing is supported as an accountability mechanism, but the intervention lacks awareness, presents a high risk to whistleblowers and regulators, including the risk of physical elimination, and is fraught with institutional and operational challenges. In effect, awareness of whistleblowing laws, operational challenges and an institutional environment conducive to venality undermine the efficacy of whistleblowing in Nigeria.

The study presents a model of challenges and opportunities for whistleblowing in a developing democracy. The authors argue that the existence of a weak and complex institutional environment and the failure of program institutionalization explain those challenges and opportunities. The authors also argue that a culturally anchored and institutionalized whistleblowing program encourages positive civic behavior by incentivizing citizens to act as custodians of their resources, and it gives voice to the voiceless who have endured decades of severe hardship and loss of dignity due to corruption.

Because of the significant differences in the features and requirements of specific products and the capabilities of various additive manufacturing (AM) solutions, selecting the most appropriate AM technology can be challenging. This study aims to propose a method to solve the complex process selection in 3D printing applications, especially by creating a new multicriteria decision-making tool that takes the direct certainty of each comparison to reflect the decision-maker’s desire effectively.

The methodology proposed includes five steps: defining the AM technology selection decision criteria and constraints, extracting available AM parameters from the database, evaluating the selected AM technology parameters based on the proposed decision-making methodology, improving the accuracy of the decision by adopting newly proposed weighting scheme and selecting optimal AM technologies by integrating information gathered from the whole decision-making process.

To demonstrate the feasibility and reliability of the proposed methodology, this case study describes a detailed industrial application in rapid investment casting that applies the weightings to a tailored AM technologies and materials database to determine the most suitable AM process. The results showed that the proposed methodology could solve complicated AM process selection problems at both the design and manufacturing stages.

This research proposes a unique multicriteria decision-making solution, which employs an exclusive weightings calculation algorithm that converts the decision-maker's subjective priority of the involved criteria into comparable values. The proposed framework can reduce decision-maker's comparison duty and potentially reduce errors in the pairwise comparisons used in other decision-making methodologies.