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Recycling construction waste is a promising way towards sustainable development in construction. Recycled aggregate (RA) is obtained from demolished concrete structures, laboratory crushed concrete, concrete waste at a ready mix concrete plant and the concrete made from RA is known as RA concrete. The purpose of this study is to apply multiple linear regressions (MLRs) and artificial neural network (ANN) to predict the mechanical properties, such as compressive strength (CS), flexural strength (FS) and split tensile strength (STS) of concrete at the age of 28 days curing made completely from the recycled coarse aggregate (RCA).

MLR and ANN are used to develop a prediction model. The model was developed in the training phase by using data from a previously published research study and a developed model was further tested by obtaining data from laboratory experiments.

ANN shows more accuracy than MLR with an R²-value of more than 0.8 in the training phase and 0.9 in a testing phase. The high R²-value indicates strong relation between the actual and predicted values of mechanical properties of RCA concrete. These models will help construction professionals to save their time and cost in predicting the mechanical properties of RCA concrete at 28 days of curing.

ANN with rectified linear unit transfer function and backpropagation algorithm for training is used to develop a prediction model. The outcome of this study is the prediction model for CS, FS and STS of concrete at 28 days of curing.

This paper aims to examine how character strengths have an important dual role in mental health in both promoting well-being and mental wellness and also in reducing symptoms and suffering. While there are many studies that have touched upon variables that character strengths can enhance for mental well-being or reduce for suffering, the author actually knows very little about how character strengths might relate to or impact mental health.

A large-scale study of 12,050 individuals was conducted to explore the self-perceived character strengths that are most helpful for mental health, for handling physical adversity, for handling social adversity and for fostering psychological well-being.

Some character strengths showed a general effect – showing a strong perceived impact across multiple domains – such as love, perspective, kindness, hope, humor and curiosity. Other character strengths showed a specific effect in that there was a strong perceived impact in one domain, such as perseverance and self-regulation for physical health, spirituality and social intelligence for social health and creativity for mental health. A strength-based approach to understanding and managing emotions was substantially more preferred than cognitive or behavioral approaches. Other findings examined the character strengths most desired to be improved upon for mental health.

The research strategy was cross-sectional, thereby causality cannot be determined. Because of the large sample size, researchers are encouraged to consider examining the findings in intervention studies.

This study indicates that character strengths are highly relevant for mental health, all 24 character strengths are possible pathways to impact mental health (some more than others) and individuals can readily connect ways they can use their character strengths to positively improve their well-being and manage their suffering.

Character strengths and their substantial positive potential provide an avenue for public impact on a large scale.

To the best of the author’s knowledge, this is the first known study to directly examine multiple intersections among mental health and character strengths in a large sample.

This paper explains why some firms manage to capture disproportionate value from their network of relationships, leading to superior performance. The paper examines how a firm's dependencies affect its value appropriation potential (VAP) in economic networks.

The paper follows the axiomatic method and the embeddedness perspective of firms to develop an index called nodal power, which captures the power that accrues to a firm in exchange-based economic networks. Thereafter, using the formal method and simulation, it shows nodal power reflects a firm's VAP in economic networks.

The study analysis and findings prove that a firm's dyadic level exchange relations and the embedded network structure determine its VAP by affecting the nodal power. A firm with lesser nodal power is likely to appropriate less value from its relations even if it equally contributes to the value creation. This finding explains how the structural and relational characteristics of a firm's network enable disproportionate value appropriation.

Nodal power furthers the scope of analyzing firms' economic relationships and changing power equations in dynamic networks. It can help firms build optimal strategic networks and manage the portfolio of relationships by predicting the impact of changing relations on firms' VAP.

The paper's original contribution is to explain, through formal analysis, why and how the structure and nature of relations of firms affect their VAP. The paper also formalizes the power-dependence principle through a dependency-based index called nodal power and uses it to show how interfirm dependencies are key to value appropriation.

Employees play a vital role in the success of a corporation. While boards of directors are created to protect shareholders’ interests, it is unclear if these directors also ensure employee welfare. In this vein, our paper examines the relationship between board leadership structure and employee well-being.

The authors employ several analysis techniques, including univariate analysis, ordinary least squares (OLS) regressions, two-stage least squares (2SLS) regressions, propensity score matching methodology, the Heckman Selection model and difference-in-differences analysis. The sample comprises USA public firms for the period 1998–2018.

Our findings indicate that having an independent chairperson can significantly benefit the welfare of employees, especially for firms with overly powerful chief executive officers (CEOs) and during times of financial distress.

Independent leadership structure is one of the crucial board characteristics that have not been examined to explain employee welfare at firms. We find that an independent chairperson can mitigate the negative effect of overly powerful CEOs on employee benefits. Importantly, independent chairpersons are beneficial for employees in difficult times and when CEOs are busy with daily activities.

The purpose of this paper is to describe various aspects of the visco-elastoplastic (VEP) behavior of porous-hardened concrete samples in relation to standard tests.

The problem is formulated on the basis of the rheological-dynamic analogy (RDA). In this study, changes in creep coefficient, Poisson's ratio, damage variables, modulus of elasticity, strength and angle of internal friction as a function of porosity are defined by P and S wave velocities. The RDA model provides a description of the degradation process of material properties from their peak state to their ultimate values using void volume fraction (VVF).

Compared to numerous versions of acoustic emission tracking developed to analyze the behavior of total wave propagation in inhomogeneous media with density variations, the proposed model is comprehensive in interpretation and consistent with physical understanding. The comparison of the damage variables with the theoretical variables under the assumption of spherical voids in the spherical representative volume element (RVE) shows a satisfactory agreement of the results for all analyzed samples if the maximum porosities are used for comparison.

The paper presents a new mathematical-physical method for examining the effect of porosity on the characteristics of hardened concrete. Porosity is essentially related to density variations. Therefore, it was logical to define the limit values of porosity using the strain energy density.

This chapter explores the writings of Pakistani sociologist Hamza Alavi, especially on the post-colonial state, ethnicity, peasantry and kinship relations. In contradistinction to most (partial) uptakes of Alavi, I evaluate his work as a whole in order to shed light on its continuities and discontinuities. I demonstrate both the strengths and pitfalls of Alavi's theorisation of the post-colonial state, mode of production and ethnicity by placing him in context of wider Marxist debates at the time. I then suggest that Alavi's other work (e.g. on the peasantry and kinship relations) may serve to complement the weaknesses of the former. Thus, by reading Alavi contra Alavi, I advocate for an ‘integral’ perspective on the relations between civil and political society, arguing for a conjunctural awareness of mediations between the same, and their imbrications with differentiated relations of class, ethnicity and kinship.

The purpose of this study was to examine how well a strength-based program grounded in positive psychology principles can advance the practical critical thinking skills of those pursuing the teacher training course.

This study used a single-group pre-test post-test design with 35 teacher-trainees from the Bachelor of Education course. The two-and-a-half-week strength-based program used the values in action survey to identify strengths. Pre- and post-test scores, measured with the Cornell Critical Thinking Test – Level Z, underwent Statistical Package for Social Sciences analysis including paired samples t-test for subcomponent and overall composite analysis.

Analysis of the pre- and post-test scores demonstrated a statistical significance in the critical thinking scores obtained by the teacher-trainees. Post-test scores were consistently significant. Out of the elements of critical thinking, induction, meaning, observation and credibility were more prominent. Deduction and assumption identification were also having a significant effect.

Most critical thinking programs focus on evaluating specific teaching methods for improving critical thinking skills. In education, positive psychology studies often center on students’ well-being, attention spans and academic success, aligning with wellness programs. Despite the importance of strengths in positive psychology, there is a lack of research on using a strength-based approach to boost critical thinking skills. This study aims to enhance teacher-trainees’ critical thinking by leveraging their individual strengths, moving away from traditional instructional strategies.

To understand differences in visitors' travel motivations, this study investigates the relations between personal values and travel motivations as well as the moderating effects of visit experience, age and gender on values–motivations relations among Australian visitors visiting Indonesia.

The multigroup confirmatory factor analysis (MGCFA) was performed using Analysis of Moment Structures (AMOS) to assess the constructs' validity across groups (potential vs repeat visitors; younger vs older visitors; male vs female visitors). A group model comparison thus was run in the multigroup analysis to test whether any differences in values–motivations relationships were significant across the groups.

This study shows that travel motivations are associated with values in a systematic way, and values–motivations relations can vary by age, gender and visit experience. Specifically, self-enhancement values are associated with escape-seeking motivation and conservation values are associated with assurance-seeking motivations. Whilst, there is no associations found between openness to change values and novelty-seeking motivations and between self-transcendence values and interaction-seeking motivations. Further, values influence travel motivations for potential but not repeat visitors and for younger but not older visitors.

Tailoring marketing strategies to align with visitors' personal values and travel motivations is crucial. Further, acknowledging the moderating influences of visit experience, gender and age in values–motivations relations enables destination marketers to create more effective and targeted approaches for diverse demographic groups in marketing, promotions and destination development.

This study for the first time provides a better explanation on how the travel motivations are formed in relation to values, age, gender and visit experience.

With the technological progress, high-performance materials are emerging in the market of additive manufacturing to comply with the advanced requirements demanded for technical applications. In selective laser sintering (SLS), innovative powder materials integrating conductive reinforcements are attracting much interest within academic and industrial communities as promising alternatives to common engineering thermoplastics. However, the practical implementation of functional materials is limited by the extensive list of conditions required for a successful laser-sintering process, related to the morphology, powder size and shape, heat resistance, melt viscosity and others. The purpose of this study is to explore composite materials of polyamide 12 (PA12) incorporating multi-walled carbon nanotubes (MWCNT) and graphene nanoplatelets (GNP), aiming to understand their suitability for advanced SLS applications.

PA12-MWCNT and PA12-GNP materials were blended through a pre-optimized process of mechanical mixing with various percentages of reinforcement between 0.50 wt.% and 3.00 wt.% and processed by SLS with appropriate volume energy density. Several test specimens were produced and characterized with regard to processability, thermal, mechanical, electrical and morphological properties. Finally, a comparative analysis of the performance of both carbon-based materials was performed.

The results of this research demonstrated easier processability and higher tensile strength and impact resistance for composites incorporating MWCNT but higher tensile elastic modulus, compressive strength and microstructural homogeneity for GNP-based materials. Despite the decrease in mechanical properties, valuable results of electrical conductivity were obtained with both carbon solutions until 10^–6 S/cm.

The carbon-based composites developed in this research allow for the expansion of the applicability of laser-sintered parts to advanced fields, including electronics-related industries that require functional materials capable of protecting sensitive devices against electrostatic discharge.

This study aims to examine whether and why subsidiary-unit managers’ prior international work experiences across multinational enterprises’ (MNEs) home and host countries impact their subsidiary-unit performance, considering the mediating effect of their advice networks.

A survey on 222 subsidiary-unit managers (154 parent country nationals [PCNs] and 68 host country nationals [HCNs]) of a Korean MNE operating in China, Vietnam, Thailand, Singapore, Hungary and Slovakia was conducted. The authors analyzed the data using partial least square structural equation modeling, multigroup analysis and bootstrapping techniques.

PCN subsidiary managers with more prior international work experience manage better-performing units due to the strength of the manager’s advice networks across local parties. However, for HCN subsidiary managers, this study did not find such mediating roles of the size and strength of their advice networks in the MNE home country.

This study provides novel insights and empirical evidence about the effect of the length of prior international work experience of subsidiary managers on their advice-seeking networks and subsidiary-unit performance. In addition, it draws on and add to social capital theory about how international work experience impacts dealing with local businesses and the relationship with corporate headquarters.