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This paper aims to investigate the effect of laser energy density on the fretting wear properties of TC4 alloys prepared by selective laser melting to enhance their service life.

The friction test used a ball-to-plane contact structure and simulated the actual working conditions by applying a linear reciprocating motion. In the experiments, the authors prepared TC4 alloys using different laser energy densities and performed fretting wear tests with D = 100 µm on a friction machine, as well as comparative analyses with conventional cast TC4 materials. 3D optical microscope, scanning electron microscopy and energy spectrum x-ray spectrometer were used to analyze the surface morphology and elemental content of the samples.

The results indicate that the friction coefficient and wear volume of selective laser melting (SLM)-TC4 are lower than those of cast TC4, demonstrating superior wear resistance. As the laser energy density increases, the grain size of the SLM-TC4 samples gradually coarsens, leading to an initial improvement followed by a decline in friction coefficient and wear resistance. Among the samples, ET3 (42 J/mm³) exhibits the lowest friction coefficient and wear volume, with the friction coefficient ranging from 0.67 to 0.7 and the wear volume being only 9.92% of that of cast TC4.

The main contribution of this work is to provide a new reference for improving the wear resistance of TC4 prepared by selective laser melting. By studying the effect of different laser energy densities on the wear resistance of TC4, it provides a theoretical basis for the preparation of SLM-TC4 alloys for industrial applications.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-11-2024-0414/

The purpose of this study is to simulate the temperature distribution during an electron beam freeform fabrication (EBF³) process based on a fully threaded tree (FTT) technique in various scales and to analyze the temperature variation with time in different regions of the part.

This study presented a revised model for the temperature simulation in the EBF³ process. The FTT technique was then adopted as an adaptive grid strategy in the simulation. Based on the simulation results, an analysis regarding the temperature distribution of a circular deposit and substrate was performed.

The FTT technique was successfully adopted in the simulation of the temperature field during the EBF³ process. The temperature bands and oscillating temperature curves appeared in the deposit and substrate.

The FTT technique was introduced into the numerical simulation of an additive manufacturing process. The efficiency of the process was improved, and the FTT technique was convenient for the 3D simulations and multi-pass deposits.

This study aims to explore the mediating effect of organization culture (OC) in the influence of emotional intelligence on the high-performance leadership of Chinese woman leaders.

A quantitative study to analyze survey data from 290 women leaders in the Ning Xia Hui Autonomies Region private and public sectors based in Northwest China.

The results indicate that emotional intelligence has a positive influence on woman leadership performance in China. woman leaders with higher emotional intelligence may have higher leadership performance. Further, emotional intelligence positively influences organization culture; OC also positively influences high-performance leadership. And the study also indicates OC mediates the relationship between emotional intelligence and woman leaders’ high-performance leadership in China, which means that OC promote and reinforce the relationships between emotional intelligence and high-performance leadership in China. Therefore, organizations should pay more attention to the construction of OC to help Chinese woman leaders and organizations succeed.

This study may catalyze positive social change in leadership development and management by helping women leaders implement effective leadership performance in a complex and global workforce. And to help women leaders increase their understanding of emotional intelligence, OC and its influence has on their performance. The proposed model of this study may help Chinese leaders put emotional intelligence, OC and high-performance leadership of woman leaders into a careful and integrated consideration. Professionals could use these results as a catalyst to develop a set of management plans and career development plans to improve woman’s understanding of the relationship between leadership performance and emotional intelligence. OC is critical to help women leaders present an effective leadership performance. Hence, this study may help women leaders successfully get more opportunities for growth and promotion in the organization.

Through the first-hand verification of organization culture, this study provides an essential theoretical and background contribution to the impact of emotional intelligence of woman leaders on high-performance leadership. In addition, the study also has forward-looking thinking, that is, the second-order reflection-reflection model of OC and high-performance leadership of woman leaders, which will provide a new vision for variance-based partial least squares-structural equation modeling.

Although scholarly inquiry into entrepreneurial stress has existed for nearly 40 years, little is known about how events drive stress responses in entrepreneurs, and how entrepreneur coping responses impact their well-being, relationships, and venture performance. In response to these deficiencies, the authors propose a stress events theory (SET) which they apply to an entrepreneurial context. The authors begin by providing a brief review of existing literature on entrepreneurial stress, which highlights unique stressors and events that entrepreneurs encounter. The authors then introduce event systems theory as developed by Morgeson, Mitchell, and Liu (2015). From this foundation, the authors develop SET, which describes how entrepreneurs react to particular event characteristics (novelty, disruptiveness, criticality, and duration). Additionally, the authors propose that how entrepreneurs interpret events drives coping choices, and that the accuracy of these coping choices subsequently differentiates the quality of entrepreneur well-being, interpersonal relationships, and venture-related consequences. The authors conclude with a discussion of contributions and areas of future research using our proposed theory.

This paper aims to investigate the thermal oxidation behavior of trimethylolpropane trioleate (TMPTO) base oil when exposed to Fe surfaces.

Samples of TMPTO bulk oil were placed in Fe vessels and heated in an oven to accelerate the oxidation at different time intervals, while others were placed in glass vessels and used as experimental controls. Subsequently, the physicochemical properties of the oxidized TMPTOs, including the kinematic viscosity and acid value, were measured and a structural analysis was conducted using the Raman and Fourier transform infrared (FTIR) techniques.

The results demonstrate that the TMPTO bulk oil exhibited an exponential increase in the kinematic viscosity along with the increasing acid value over the oxidation time. The Fe surface significantly increased the kinematic viscosity of TMPTO, while only mildly impacting its acid value compared with the experimental controls. The structural analysis results of the TMPTO suggest that the C = C and = C-H bonds were the vulnerable sites. Furthermore, the results suggest that the Fe surface evidently accelerates the chemical reactions of the C = C and the = C-H bonds, and less alcohols and more carbonyl products were identified in the oil samples that were heated in the Fe vessels.

The results demonstrate that the Fe surfaces affected the oxidation behavior of the TMPTO base oil, and an interaction mechanism between the Fe and the TMPTO is developed.

The purpose of this paper is to propose a new approach for aerodynamic parameter identification of hypersonic vehicles, which is based on Pigeon-inspired optimization (PIO) algorithm, with the objective of overcoming the disadvantages of traditional methods based on gradient such as New Raphson method, especially in noisy environment.

The model of hypersonic vehicles and PIO algorithm is established for aerodynamic parameter identification. Using the idea, identification problem will be converted into the optimization problem.

A new swarm optimization method, PIO algorithm is applied in this identification process. Experimental results demonstrated the robustness and effectiveness of the proposed method: it can guarantee accurate identification results in noisy environment without fussy calculation of sensitivity.

The new method developed in this paper can be easily applied to solve complex optimization problems when some traditional method is failed, and can afford the accurate hypersonic parameter for control rate design of hypersonic vehicles.

In this paper, the authors converted this identification problem into the optimization problem using the new swarm optimization method – PIO. This new approach is proved to be reasonable through simulation.

The purpose of this paper is to expound the relationship among microstructure, mechanical property, tribological behavior and deformation mechanism of carburized layer deposited on Ti-6Al-4V alloy by double-glow plasma hydrogen-free carburizing surface technology.

Morphologies and phase compositions of the carburized layer were observed by scanning electron microscope and X-ray diffraction. The micro-hardness tests were used to evaluate the surface and cross-sectional hardness of carburized layer. The reciprocating friction and wear experiments under various load conditions were implemented to investigate the tribological behavior of carburized layer. Moreover, scratch test with ramped loading pattern was carried out to illuminate the deformation mechanism of carburized layer.

Compared to substrate, the hardness of surface improved to ∼1,100 HV_0.1, while the hardness profile of carburized layer presented gradual decrease from ∼1,100 to ∼300 HV_0.1 within the distance of the total carburizing-affected region about 30 µm. The coefficient of friction, wear rate and wear morphology of carburized layer were analyzed. Scratch test indicated that the deformation process of carburized layer could be classified into three mechanisms (elastic, changing elastic–plastic and stable elastic–plastic mechanisms), and the deformation transition of the carburizing-affected region was from changing elastic–plastic to elastic mechanisms. Both the elastic and changing elastic–plastic mechanisms are conducive to the wearing course.

Using this technology, hydrogen embrittlement was avoided and wear resistance property of titanium alloy was greatly improved. Simultaneously, the constitutive relation during the whole loading process was deduced in terms of scratch approach, and the deformation mechanism of carburized layer was discussed from a novel viewpoint.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-11-2019-0489/

The purpose of this paper is to propose a novel maximum power point track (MPPT) controller for a type of solar quad-copter to solve the problem of tracking the maximum power point (MPP) when it works in nonuniform environment conditions.

The influence of uniform and nonuniform illumination and different temperatures results in the output characteristics of the solar array arising multiple local MPPs. To track the global MPP of the solar array on the designed solar quadcopter, a type of MPPT controller based on an improved pigeon-inspired optimization (PIO) algorithm is proposed.

A novel type of MPPT controller based on extended search PIO (ESPIO) algorithm, called ESPIO–MPPT controller, is introduced emphatically, which is used to extend the solar quadcopter’s flight time. The simulation experiments show that the ESPIO–MPPT controller can find the global MPP (GMPP) with smaller amplitudes of oscillation and less time cost.

The proposed solar quadcopter with ESPIO–MPPT controller has satisfactory flight performance which can greatly broaden its mission scope.

A type of efficient MPPT algorithm based on ESPIO is proposed for GMPP tracking of solar quadcopters in nonuniform environment conditions.

This chapter explains how and why the knowledge economy will increase the demand for knowledge engineering. It defines and traces the evolution of knowledge engineering. It identifies the two components of knowledge engineering – elicitation and representation. It discusses the increased importance of tacit knowledge, specifically know-what and know-how, for organizations and companies. The increased demand for knowledge engineering calls for increased number of knowledge engineers. Knowledge engineering will expand beyond its current homes in systems development and cognitive science. The MASK methodology is an important intermediary between formal knowledge engineering and the methods needed to develop natural language and conceptual modeling for the knowledge economy.

This paper aims to investigate how organization capital influences different forms of corporate risk. It also explores how the relationship between organization capital and risks varies in the cross-section of firms.

To test the hypothesis, this study employs the ordinary least squares (OLS) regression model using a large sample of the United States (US) data over the 1981–2019 period. It also uses an instrumental variable approach and an errors-in-variables panel regression approach to mitigate endogeneity problems.

The empirical results show that organization capital is positively related to both idiosyncratic risk and total risk but negatively related to systematic risk. The cross-sectional analysis shows that the positive relationship between organization capital and idiosyncratic risk is significantly more pronounced for the subsample of firms with high information asymmetry and human capital. Moreover, the negative relationship between organization capital and systematic risk is significantly more pronounced for firms with greater efficiency and firms facing higher industry- and economy-wide risks.

The findings have important implications for investors and policymakers. For example, since organization capital increases idiosyncratic risk and total risk but reduces systematic risk, investors should take organization capital into account in portfolio formation and risk management. Moreover, the findings lend support to the argument on the recognition of intangible assets in financial statements. In particular, the study suggests that standard-setting bodies should consider corporate reporting frameworks to incorporate the disclosure of intangible assets into financial statements, particularly given the recent surge of corporate intangible assets and their critical impact on corporate risks.

To the best of the authors' knowledge, this is the first study to adopt a large sample to provide systematic evidence on the relationship between organization capital and a wide range of risks at the firm level. The authors show that the effect of organization capital on firm risks differs remarkably depending on the kind of firm risk a particular risk measure captures. This study thus makes an original contribution to resolving competing views on the effect of organization capital on firm risks.