bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of turbulence intensity on aerodynamic characteristics of extended trailing edge airfoil
Authors: Livya E. , Nadaraja Pillai S. 
Published: May 2022

Purpose
This paper aims to study the extended trailing edge airfoil for a range of angle of attack at different intensities of turbulence.

Design/methodology/approach
In this paper, an experimental study on NACA 0020 airfoil with thin extended trailing edge modification of amplitude of h = 0.1c, 0.2c and 0.3c at the Reynolds number of 2.14 × 105 are tested. The research was carried out for an angle of attack ranging from 0° = α = 35° for the turbulence intensity of 0.3%, 3%, 5%, 7% and 12%. From the experimental readings, the surface pressures are scanned using a Scanivalve (MPS2464) pressure scanner for a sampling frequency of 700 Hz. The scanned pressures are converted to aerodynamic force coefficient and the results are combined and discussed.

Findings
The airfoil with the extended trailing edge will convert the adverse pressure gradient to a plateau pressure zone, indicating the delayed flow separation. The CL value at higher turbulence intensity (TI = 12%) for the extended trailing edge over perform the base airfoil at the post-stall region. The maintenance of flow stability is observed from the spectral graph.

Practical implications
A thin elongated trailing edge attached to the conventional airfoil serves as a flow control device by delaying the stall and improving the lift characteristics. Additionally, extending the airfoil's trailing edge helps to manage the performance of the airfoil even at a high level of turbulence.

Originality/value
Distinct from existing studies, the presented results reveals how the extended trailing edge attached to the airfoil performs in the turbulence zone ranging from 0.3% to 12% of TI. The displayed pressure distribution explains the need for increasing trailing edge amplitude (h) and its impact on flow behaviour. The observation is that extended trailing edge airfoil bears to maintain the performance even at higher turbulence region.
Does attention mechanism possess the feature of human reading? A perspective of sentiment classification task
Authors: Zhao Lei , Zhang Yingyi , Zhang Chengzhi 
Published: May 2022

PurposeTo understand the meaning of a sentence, humans can focus on important words in the sentence, which reflects our eyes staying on each word in different gaze time or times. Thus, some studies utilize eye-tracking values to optimize the attention mechanism in deep learning models. But these studies lack to explain the rationality of this approach. Whether the attention mechanism possesses this feature of human reading needs to be explored.Design/methodology/approachThe authors conducted experiments on a sentiment classification task. Firstly, they obtained eye-tracking values from two open-source eye-tracking corpora to describe the feature of human reading. Then, the machine attention values of each sentence were learned from a sentiment classification model. Finally, a comparison was conducted to analyze machine attention values and eye-tracking values.FindingsThrough experiments, the authors found the attention mechanism can focus on important words, such as adjectives, adverbs and sentiment words, which are valuable for judging the sentiment of sentences on the sentiment classification task. It possesses the feature of human reading, focusing on important words in sentences when reading. Due to the insufficient learning of the attention mechanism, some words are wrongly focused. The eye-tracking values can help the attention mechanism correct this error and improve the model performance.Originality/valueOur research not only provides a reasonable explanation for the study of using eye-tracking values to optimize the attention mechanism but also provides new inspiration for the interpretability of attention mechanism.
Modeling and forecasting United States oil production along with the social cost of carbon: conventional and unconventional oil
Authors: Kazemzadeh Emad , Ahmadi Shadmehri Mohammad Taher , Ebrahimi Salari Taghi , Salehnia Narges , Pooya Alireza 
Published: May 2022

Purpose
The USA is one of the largest oil producers in the world. For this purpose, the authors model and predict the US conventional and unconventional oil production during the period 2000–2030.

Design/methodology/approach
In this research, the system dynamics (SD) model has been used. In this model, economic, technical, geopolitical, learning-by-doing and environmental (social costs of carbon) issues are considered.

Findings
The results of the simulation, after successfully passing the validation test, show that the US unconventional oil production rate under the optimistic scenario (high oil prices) in 2030 is about 12.62 million barrels/day (mb/day), under the medium oil price scenario is about 11.4 mb/day and under the pessimistic scenario (low oil price) is about 10.18 mb/day. The results of US conventional oil production forecasting under these three scenarios (high, medium and low oil prices) show oil production of 4.62, 4.26 and 3.91 mb/day, respectively.

Originality/value
The contribution of this study is important in several respects: First, by modeling SD that technical, economic, proven reserves and technology factors are considered, this paper models US conventional and unconventional oil production separately. In this modeling, nonlinear relationships and feedback loops are presented to better understand the relationships between variables. Second, given the importance of environmental issues, the modeling of social costs of CO2 emissions per barrel of oil is also presented and considered as a part of oil production costs. Third, conventional and unconventional US oil production by 2030 is forecast separately, the results of this study could help policymakers to develop unconventional oil and plan for energy self-sufficiency.
Dispersity, stability and tribology behavior of modified nanoserpentine in lubricating oil
Authors: Yan Yanhong , Yan Xiaocui , Yang Chengwen , Zhou Yanfei , Jia Zhining , Hao Caizhe 
Published: May 2022

Purpose
The purpose of this study is to improve the dispersion of nanoserpentine modified with OA, KH550 and KH550/oleic acid in lubricating oil. The main aims are to analyze the influence of the dispersion and stability of nanoserpentine modified by different modifiers on the friction properties of lubricating oil.

Design/methodology/approach
The nanoserpentine particles obtained by ball-milling were modified by silane coupling agent KH550, OA and KH550/OA, respectively. The dispersity and stability of nanoserpentine in base lubricating oil were characterized by the absorbance value method, centrifuge precipitation rate method and static observation method. The MMU-5G screen display friction and wear tester was used to evaluate the tribological properties of C45E4/C45E4 friction pairs in corresponding lubricating oils. The surface morphology of the friction pairs was observed by scanning electron microscopy and energy dispersive spectroscopy.

Findings
The results showed that the dispersity and stability of nanoserpentine particles in lubricating oil were best modified by OA, followed by the KH550/OA and finally, the KH550. Nanoserpentine particles modified with oleic acid showed optimum tribological properties as lubricant additives.

Originality/value
This study can improve the dispersion stability of nanoserpentine particles in lubricating oil, increasing the antiwear and antifriction performance of lubricating oil, which has great significance in economic and military aspects.
The influence of manufacturing contexts on additive manufacturing-enabled competitive capabilities
Authors: Khorram Niaki Mojtaba , Nonino Fabio , Tafakkori Keivan , Torabi S. Ali , Kazemian Iman 
Published: May 2022

PurposeThis paper presents a contingency analysis of additive manufacturing's (AM) impacts, proposes a novel form of AM-enabled competitive capabilities and explores manufacturing contexts (including product-operation-organization-related factors) influencing those capabilities.Design/methodology/approachA theoretical model incorporating manufacturing competitive capabilities and contingency concepts is developed and validated using an empirical study on 105 manufacturing firms using AM. Structural equation modeling is applied for statistical data analysis.FindingsThe results indicate that the production volume and material type have contingency effects on AM-enabled product quality, cost reduction and green capabilities. Besides, it has been demonstrated that the degree of a country's economic development and the firm's experience have contingency impacts on AM's capabilities as well.Research limitations/implicationsThe contextual settings employed in this study are limited. A future contingency analysis requires further exploration of other factors (e.g. different AM technologies or application sectors) through in-depth case studies. Future studies can also be built upon the proposed framework to generalize the model for analyzing other emerging manufacturing technologies.Practical implicationsUncertainties around AM implementation and its consequences place the context of evaluation as an essential facet. The derived insights aid practitioners in aligning the firm's internal characteristics (i.e. manufacturing and organizational contexts) with AM's promising competitive capabilities.Originality/valueThe study is among the first analysis to empirically and rigorously establishes the contingency effects of manufacturing and organizational factors on competitive capabilities related to AM, using a representative sample of manufacturers spanning different countries, firm sizes and other investigated manufacturing contexts.
Employer and internal branding research: a bibliometric analysis of 25 years
Authors: Saini Gordhan K. , Lievens Filip , Srivastava Mukta 
Published: May 2022

PurposeIn the past 25 years, employer and internal branding have grown significantly. Prior reviews tended to focus on either one of these domains. This study aims to map the intellectual structure of research on both employer branding and internal branding, thereby identifying impactful authors and journals, current and evolving themes and avenues for future research.Design/methodology/approachUsing VOSviewer and Biblioshiny software packages, a bibliometric analysis of 739 articles was conducted using various methods such as citation analysis, bibliographic coupling, cluster analysis, keyword analysis and three-field plot. The Scopus results were further validated using 297 articles produced by the Web of Science data set. It ensured the robustness of the results and generalizability of the findings across bibliometric data sets.FindingsThe findings first report the impactful articles, authors and institutions of employer and internal branding research, along with popular keywords used in this area. Next, the analysis reveals four major clusters and seven subthemes (i.e. employer brand and job seekers, employer brand and employees, employer brand and international human resource management (HRM), third-party employer branding, internal branding – conceptualization/review, internal branding – antecedents and consequences, internal brand management). Early research focused more on “corporate brandings,” whereas current research deals more with “employer branding: antecedents and consequences,” “employer branding conceptualization/review,” and “internal branding” and its subthemes. The employer and internal branding clusters have evolved largely independent from each other. This study offers future research directions and practical implications per cluster.Originality/valueTo the best of the authors’ knowledge, this study is the first comprehensive bibliometric analysis of both employer and internal branding research.
Solar rooftop adoption among Indian households: a structural equation modeling analysis
Authors: Kumar Vikas , Kaushik Arun Kumar 
Published: May 2022

Purpose
This study aims to examine factors influencing purchase intentions of households toward solar rooftops, using diffusion of innovation theory.

Design/methodology/approach
Six dimensions from the diffusion of innovation theory have been contemplated to assess households’ purchase intentions toward solar rooftops. Primary data was collected from 863 respondents by using a purposive sampling technique from different parts of India. The study used structural equation modeling analysis to examine the data.

Findings
Results confirmed that the dimensions, namely, relative advantage, compatibility, complexity, innovations and observability, positively influence households’ purchase intentions of solar rooftops, except for the trialability dimension.

Research limitations/implications
Data for the study is based on a purposive sampling technique that restricts the representation of the whole population. There may be variance in public perception from place to place due to demographic and psychographic differences.

Practical implications
The present study would facilitate devising a roadmap to improve the quality of the environment. Policy planners, researchers and professionals would find the implications of this study helpful in developing critical strategies.

Originality/value
The research practically explores households’ intention to purchase solar rooftops by filling the gap in previous literature. Findings of the study can equip firms with several advantages. Through the present study, one gets to know that developed and developing economies have similar energy usage issues. Further, it empirically examines the applicability of diffusion of innovation theory in the solar rooftops context.
A vertical coupling dynamic analysis method and engineering application of vehicle–track–substructure based on forced vibration
Authors: Li Guolong , Gao Mangmang , Yang Jingjing , Wang Yunlu , Cao Xueming 
Published: May 2022

PurposeThis study aims to propose a vertical coupling dynamic analysis method of vehicle–track–substructure based on forced vibration and use this method to analyze the influence on the dynamic response of track and vehicle caused by local fastener failure.Design/methodology/approachThe track and substructure are decomposed into the rail subsystem and substructure subsystem, in which the rail subsystem is composed of two layers of nodes corresponding to the upper rail and the lower fastener. The rail is treated as a continuous beam with elastic discrete point supports, and spring-damping elements are used to simulate the constraints between rail and fastener. Forced displacement and forced velocity are used to deal with the effect of the substructure on the rail system, while the external load is used to deal with the reverse effect. The fastener failure is simulated with the methods that cancel the forced vibration transmission, namely take no account of the substructure–rail interaction at that position.FindingsThe dynamic characteristics of the infrastructure with local diseases can be accurately calculated by using the proposed method. Local fastener failure will slightly affect the vibration of substructure and carbody, but it will significantly intensify the vibration response between wheel and rail. The maximum vertical displacement and the maximum vertical vibration acceleration of rail is 2.94 times and 2.97 times the normal value, respectively, under the train speed of 350 km·h−1. At the same time, the maximum wheel–rail force and wheel load reduction rate increase by 22.0 and 50.2%, respectively, from the normal value.Originality/valueThis method can better reveal the local vibration conditions of the rail and easily simulate the influence of various defects on the dynamic response of the coupling system.
Integrating disaster resilience into green rating systems – a modification of the Sri Lankan green building rating tool
Authors: Abeysinghe Sonali , De Zoysa Chandula Jithmi , Siriwardana Chandana , Bandara Chaminda , Dissanayake Ranjith 
Published: May 2022

PurposeThe purpose of the study is to mainstream the disaster risk reduction (DRR) and disaster resilience measures into the GreenSL® building rating system in Sri Lanka to demonstrate a more holistic approach in achieving sustainability with resilience.Design/methodology/approachFirst, a comprehensive literature review was carried out on green building practices and rating tools, natural hazards and DRR and global and local frameworks. Next, criteria were developed incorporating the disaster resilience aspects through eight expert committee meetings and included the rating tool in three levels. Finally, 11 green-certified buildings from the Green Building Council of Sri Lanka were reevaluated using the new disaster resilient GREENSL® rating system for built environment as a validation for the new tool and to analyze the new certification levels.FindingsAll the green-certified buildings in hazard-prone areas dropped their certification by one level while the buildings in nonhazard-prone areas remained in the certification after being evaluated by the new DRR-incorporated rating system, which recommends the use of new tool for the buildings in hazard-prone areas. But due to the rapid changes in climate and the unpredictable trends of natural hazards, the use of new DRR incorporated GREENSL® rating system for built environment for the certification of buildings is highly endorsed.Originality/valueThis is the first research study based on the GREENSL rating system. And it is the first effort to incorporate DRR aspects to any rating tool in Sri Lanka. The projects that were evaluated for the validation of the new tool are the actual projects which obtained green building certification. Also, it is apparent that this study has gone some way towards enhancing the understanding of blending the sustainability and resilience in rating systems for built environment.
HighMHCdiversity confers no advantage for phenotypic quality and reproductive performance in a wild bird
Authors: Pikus Ewa , Dunn Peter O. , Minias Piotr 
Published: May 2022

AbstractGenes of the major histocompatibility complex (MHC) encode antigen‐binding molecules and are an integral part of the acquired immune response of vertebrates. In general, high individual MHC diversity is expected to increase fitness by broadening the spectrum of pathogens recognized by the immune system, in accordance with the heterozygote advantage mechanism. On the other hand, the optimality hypothesis assumes that individuals with optimal (intermediate), rather than maximum, diversity of the MHC will achieve the highest fitness because of inherent costs associated with expressing diverse MHC alleles.Here, we tested for associations between individual diversity of the MHC class I and class II genes (binding antigens of intra‐ and extracellular pathogens respectively) and a range of fitness‐related traits (condition, ornament expression and reproduction) in an urban population of the Eurasian cootFulica atra.Contrary to our expectation, we found that high within‐individual allelic diversity of MHC genes (both class I and II) was associated with poorer condition (lower blood haemoglobin concentrations), weaker expression of the putative ornament (smaller frontal shield), later onset of breeding and smaller clutches. An analysis of functional MHC allele clusters (supertypes) provided further support for negative associations of MHC diversity with phenotypic quality and reproductive performance, but most of these relationships could not be explained by the presence of specific maladaptive supertypes. Finally, we found little empirical support for the optimality hypothesis in the Eurasian coot.Our results suggest that the costs of high MHC diversity outweighed any benefits associated with broad MHC repertoire, which could be driven by depauperate pathogen diversity in an urban landscape. To the best of our knowledge, this is one of the first studies providing consistent evidence for negative associations of MHC diversity with a range of fitness‐related traits in a natural avian population.
Competition mediates understorey species range shifts under climate change
Authors: Sanczuk Pieter , De Lombaerde Emiel , Haesen Stef , Van Meerbeek Koenraad , Luoto Miska , Van der Veken Bas , Van Beek Eric , Hermy Martin , Verheyen Kris , Vangansbeke Pieter , De Frenne Pieter 
Published: May 2022

Abstract

Biological communities are reshuffling owing to species range shifts in response to climate change. This process inherently leads to novel assemblages of interacting species. Yet, how climatic change and local dynamics in biotic interactions jointly affect range shifts is still poorly understood.

We combine a unique long‐term transplant competition‐exclusion experiment with species distribution models (SDMs) to test the effects of biotic interactions on understorey species range shifts under climate change in European temperate forests. Using a time series of 18 years of individual‐level demographic data of four common understorey plant species transplanted beyond their cold range edge to plots with and without interspecific competition, we built integral projection models (IPMs) and analysed the effects of competition on five key vital rates and population growth (λ). We assessed the results of the transplant experiment in the context of the modelled species' current and future potential distributions.

We find that species' population performances in the transplant experiment decreased with lower predicted habitat suitability from the SDMs. The population performance at the transplant sites was mediated by biotic interactions with the local plant community: for two species with intermediate levels of predicted habitat suitability at the transplant sites, competition effects could explicitly differentiate between net population growth (λ > 1) or shrinkage (λ < 1).

Synthesis. Our findings contest the long‐standing idea that at cold range edges, mainly abiotic factors structure species' distributions. We conclude that biotic interactions, through acting on local population dynamics, may impact species distributions at the continental scale. Hence, predicting climate‐change impacts on biodiversity redistributions ultimately requires us to also integrate dynamics in biotic interactions.