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Tidal turbine arrays have undergone extensive research to determine the optimal spacing for efficient performance and reduced wake generation. Small-scale laboratory tests are typically conducted to analyze wake structures prior to deployment. These tests often result in conditions of extreme blockage due to channel narrowing in comparison to turbine size. The primary objective of this study is to investigate flow behavior around turbines under blockage conditions and their performance close to the free surface, both in current-only and wave-and-current scenarios. The methodology employed a combination of blade element momentum theory and computational fluid dynamics (CFD) integrating a virtual blade model (VBM) code. The findings of this study indicate potential enhancements in tidal turbine array performance of up to 7% in lateral arrangements and 11% in streamwise arrangements under blockage conditions. The wake is significantly influenced by surface waves, which also contribute to increased downstream turbine performance. [ABSTRACT FROM AUTHOR]

This document introduces a novel concept involving an Omni-Directional Guided Vane (ODGV) encompassing a vertical axis wind turbine (VAWT) with the goal of improving its overall performance. Extensive three-dimensional computational analysis of the airfoils used in this novel ODGV structure is conducted to investigate the impact of various geometric parameters. Diverse geometric configurations of the ODGV are explored to analyze wind flow behavior across the turbine utilizing a well-validated computational fluid dynamics (CFD) model. The numerical investigations employ the Reynolds Averaged Navier–Stokes (RANS) modeling approach with the k-epsilon turbulence model. The steady state governing equations are solved using the validated CFD solver STAR CCM+. The study considers three distinct inlet velocities: 3, 6, and 9 m/s, with the aim of improving flow behavior and velocity through the ODGV. Four different modifications of the ODGV are examined, and the accuracy of the CFD model is affirmed through comparison with NACA airfoil data. Integration of the ODGV results in an enhanced self-starting behavior of the VAWT, leading to a reduction in the cut-in speed. Validation results demonstrate a strong agreement with the data obtained from CFD simulations. These results suggest that most shape ratios, except for 0.3 and 0.4 at Tip Speed Ratio (TSR) of 1.3 and 3, contribute to enhancing power and torque coefficients. Furthermore, the findings indicate that with a Sharpe ratio of 0.56, both torque and power coefficients could be improved by up to 48% and 58%, respectively. [ABSTRACT FROM AUTHOR]

Lifetime analyses comprise the techniques dealing with observations obtained from the occurrence of a specified event(s). In most of the situations dealing with lifetime observations, some units are recorded as censored observations. Dealing with censored observations makes these techniques unique. Countless standard statistical tools are available for inference based on censored lifetime observations. These classical techniques consider lifetime observations as precise numbers and ignore the uncertainty of single observations. Whereas in practical applications it is not possible to measure life times as precise numbers, they are always more or less nonprecise. The imprecision in measurements can be covered by neutrosophic set. Fuzzy estimators for life time distributions potentially use neutrosophic system to model and analyze the inherent uncertainties and neutalities present in the data and the parameter estimates. This study aimed to obtain estimators for the Weibull parameters and two exponential parameters based on the up-to-date fuzzy number approach, a special case for neutrosophic set. The suggested estimators incorporate fuzziness in addition to random variation, which makes these estimators more realistic. The same techniques need to be extended to fuzzy and neutrosophic sets. [ABSTRACT FROM AUTHOR]

Increasing contamination of water bodies with antibiotics has necessitated the development of novel mitigation methods. Many studies have applied adsorption and photocatalytic processes using different nanoparticles, metal‐organic frameworks, etc., as sorbents and photocatalysts for antibiotics removal. Among these materials, the development of molecular imprinted polymers (MIPs) is desirable owing to their low cost, structural predictability, detection at deficient concentrations, and versatile applicability. These attributes further encouraged researchers to fabricate hybrid MIP‐based materials to abate antibiotic contamination in wastewater. This review summarizes recent studies that deal with conventional and hybrid MIPs such as MIPs‐hybrid carbon nanomaterials, magnetic nanomaterials, advanced MIP‐based sensors, and photocatalytic materials MIPs for synergic adsorption/separation of antibiotic residuals from wastewater. Economic perspectives of the emerging hybrid materials are also discussed. Some limitations, research gaps, and future potentials for further advancement and efficient remediation results are outlined. [ABSTRACT FROM AUTHOR]

Synopsis The research problem In this study, we examined the effect of an important informal institution, namely, national culture, on audit fees in an international context. Motivation In recent years, extant literature has increasingly focused on country-level differences in the audit environment, as these might have a significant influence on how financial statement audits are conducted across the globe. We contribute to this stream of literature by investigating the impact of national culture on audit fees. The test hypotheses Based on the demand- and supply-side perspectives of audit fees, we hypothesized that national culture dimensions — namely, uncertainty avoidance, power distance, individualism versus collectivism, and masculinity versus femininity — affect audit fees. Target population We used a sample of 27,670 firm-year observations across 22 countries over the 2002–2019 period. Adopted methodology We used ordinary least squares (OLS) regressions as baseline technique and entropy-balanced method (EBM) and system-generalized method of moments (GMM) to address endogeneity concerns. Analyses We examined the impact of Hofstede's four national culture dimensions — uncertainty avoidance, power distance, individualism versus collectivism, and masculinity versus femininity — on audit fees. We also tested the robustness of results using alternative measures of national culture, subsample analyses, and additional firm-level factors. Findings Consistent with our hypotheses, we find that audit fees are higher (lower) in countries with higher uncertainty avoidance, individualism, and masculinity (power distance) scores. Our further analyses reveal that earnings management proxied by abnormal accruals does not impact the relationship; however, country-level creditor rights influence audit fees in high power distance and masculine cultures. We also note that national culture influences auditor choice and audit opinion. Our main findings are robust to alternate proxies and subsample analysis, as well as to address potential endogeneity concerns. Overall, our findings offer important implications for firms operating in global markets and for the audit profession. [ABSTRACT FROM AUTHOR]

This study examines the association between individualistic culture and firm default risk across countries. Using a sample of 15,225 firms across 32 countries over the 2005–2018 period (115,464 firm‐year observations), we find that firms based in countries with high levels of individualism are associated with greater default risk. Our results are robust to a battery of endogeneity and other robustness checks. In additional analyses, we show that risk‐taking behavior is a channel through which individualism impacts firm default risk. We also find that the effect of individualistic culture on firm default risk is weak in countries with stringent bankruptcy laws. Overall, the findings of this study can improve our understanding of the impact of major informal institutions, such as individualistic culture, on manager behavior, which has significant implications for firms operating in global financial markets. [ABSTRACT FROM AUTHOR]

"Controlling the Capital: Political Dominance in the Urbanizing World" by Tom Goodfellow and David Jackman explores the rise of authoritarianism globally and its impact on capital cities. The book focuses on Sub-Saharan Africa and South Asia case studies, examining how authoritarian regimes establish and sustain dominance in capital cities. It discusses the relationship between cities and political dominance, contributing to debates on authoritarianism, urbanization, political contestation, resistance, development, and the prospects for democracy. The book provides historical and contemporary analysis, covering various political matters and highlighting the challenges faced by urban populations. However, it lacks a serious projection of the future of cities and their potential for democracy, and future research should address this issue. [Extracted from the article]