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This article develops a benefit curve and a cost curve that relate the strength of a CEO’s social tie to its benefits and costs respectively, and thereby develops a cost-benefit framework for understanding the strengths of CEO social ties. In particular, this framework helps address the basic, yet largely unanswered questions of why one tie is stronger than another and why a CEO utilizes social ties to a greater extent in one context than in another.

As a conceptual paper, this article develops a cost-benefit framework for understanding the strengths of CEO social ties.

This article suggests an important shift of research focus and a different way of thinking regarding tie strength. Specifically, it suggests that the more fundamental question might not be whether a social tie is beneficial or one tie is more beneficial than another, but rather what its optimal strength is, given the underlying relational factors such as resource dependence and demographic similarity. Relatedly, the question might not be whether a CEO’s level of utilization of social ties has a more positive effect on firm performance in one context than in another, but rather what the optimal level of utilization is, given the contextual factors such as environmental uncertainty.

This article addresses a widely accepted, yet potentially misleading understanding of the relationship between a tie’s strength and its benefits (i.e. the strength of weak ties argument). By doing so, it develops a benefit curve that integrates into a coherent, parsimonious function three seemingly conflicting key ideas in the literature (i.e. the overall notion that social ties are beneficial, the strength of weak ties argument, and the liability of strong ties argument). Relatedly, it develops a coherent framework for understanding the strengths of CEO social ties.

Urban planning is the blueprint for the development of urban construction and the basis for management of a city. The urban planning of China’s high-speed modernization has encountered many bottlenecks, and the gap between the daily living needs of residents and the urban planning objectives has attracted particular attention. Harmonious development between man and nature is necessary to build a harmonious society, and urban planning that is close to the needs of residents and more humanized has become the main goal of urbanization. In this paper, urban planning of Zhuhai City was studied for one year. Zhuhai focuses on building transport hub, industrial layout, and urban development in three major patterns. Many problems in the planning and management of Zhuhai City were encountered in the past, because the plans are only heavy concepts that ignore implementation and lack of comprehensive survey. Based on the concept of communication planning, the main features of the public participation in the urban planning model through modern mass media may be suitable for achieving the objectives and satisfying public needs. Urban planning and decision-making in Zhuhai City in recent years are evaluated by SWOT method. Future plans of Zhuhai City are discussed.

The purpose of this paper is twofold: first, determining which factors critically influence asymmetrical trust behaviors in construction projects within the Chinese context; second, proposing corresponding measures to deal with the asymmetrical behaviors of both the owner and the contractor promoting cooperative relationships among participants in construction organizations.

A theoretical model was developed and a questionnaire survey was conducted with 183 professionals. The data collected were analyzed by the structural equation modeling (SEM) technique.

The results identified six critical factors influencing trust asymmetry behavior in construction projects. The power imbalance, information asymmetry and cognitive difference have a positive influence on both upward-trust behavior and downward-trust behavior in the construction organization, while the competence, performance capacity and relationship satisfaction have negative effects.

This paper based on the assumption that trust asymmetry behavior has a negative impact on project performance, which should be further studied. Besides, future research may carry out a comparative analysis among the trusting relationships and behavior of different participants dynamically.

This paper contributes to the literature in three aspects. First, the factors influencing trust behavior in project organization have been identified for the first time. Second, a comprehensive view of trust asymmetry behavior has been theorized by SEM method. Third, the result bridges the existing gap caused by the lack of empirical evidence to understand the genetic mechanisms of trust asymmetry behavior in the construction industry.

This study aims to enhance the resilience of foamed concrete (FC) against carbonation and water absorption (WA) by integrating microorganisms, specifically Aspergillus iizukae EAN605.

The focus was on understanding how variables such as microorganism concentration, concrete density and water-to-cement (w/c) ratio affect these properties. Optimal results were observed under specific conditions—FC density set at 1800 kg/m³, a w/c ratio of 0.5 and an Aspergillus iizukae EAN605 concentration of 0.5 g/L—resulting in significant reductions in carbonation and WA compared to standard FC.

It is observed that fungi not only fill pores with calcium oxalate but also limit carbonation by consuming CO₂ and block water penetration through their mycelial network. A central composite design within response surface methodology was employed for the experimental design, resulting in mathematical models that align closely with the empirical data. The models identified the most effective parameters for minimizing carbonation depth: FC density at 1970 kg/m³, fungal concentration at 0.585 g/L and w/c ratio at 0.470. Further regression analysis showed a high correlation between the experimental data and the predicted outcomes, with a coefficient of determination (R²) of 92.29 and a model F-value of 16.45.

Statistical analysis highlighted the significant roles of density and fungal concentration in these reductions. Besides, scanning electron microscopy provided visual evidence of fungal-mediated mineral formation in FC, supporting the empirical findings. Overall, the study demonstrated the effective use of Aspergillus iizukae EAN605 in enhancing the durability of FC, marking an innovative stride in sustainable construction materials.

This study investigates the association between debt overhang and carbon emissions (both direct and indirect emissions) using a sample of US publicly listed firms.

The study applies generalized least squares (GLS) regression analyses to a sample of 2,043 US firm-year observations over a period of 14 years from 2007 to 2020. The methods include contemporaneous effect, lagged effect, alternative measures of carbon emissions and debt overhang, intensive versus non-intensive analysis, channel analysis, firm fixed effects, change analysis, controlling for credit rating analysis, propensity score matching approach, instrumental variable analysis with industry and year fixed effect.

This study's findings reveal that the debt overhang problem increases carbon emissions. This finding holds when the authors use alternative measures of carbon emissions and debt overhang. The authors find that carbon abatement investment is a channel that is negatively impacted by debt overhang, which in turn increases carbon emissions. This study's results are robust for several endogeneity tests, including firm fixed effects, change analysis, propensity score matching approach and two-stage least squares (2SLS) instrumental variable analysis.

The outcome of this research has policy implications for several stakeholders, including investors, firms, market participants and regulators. This study's findings offer insights for investors and firms, helping them allocate resources effectively and make financing decisions aimed at reducing carbon emissions. Regulators and policymakers can also use the findings to formulate policies that promote alternative sustainable finance practices.

The outcome of this research is likely to help firms develop their understanding of the debt overhang problem and undertake strategies that yield a significant amount of funding to invest in reducing carbon emissions.

The purpose of this study is to use an electric field technique to design novel heat sinks capable of rejecting as much heat as possible in a limited space. Configuration of electrodes in this study can be used for increasing the efficiency of heat sinks.

This study investigates a novel electrohydrodynamic (EHD)-based heat sink for thermal management of electronic devices and thermal systems. The significant part of designing an EHD heat sink is the arrangement of the electrodes. A numerical simulation is performed for a heat sink with two parallel plates to determine the optimum dimensional configuration of electrodes. The upper plate of this heat sink is the ground electrode with a constant atmosphere temperature, and the lower plate of it with flush-mounted high-voltage electrodes has uniform heat flux.

The results show that heat transfer changes by the size of the vortices and the number of them. These vortices are emerged by the electric field, and the number of them increases with increasing the number of electrodes. The interaction of vortices size and number leads to having the lowest average temperature in the optimum case by two high voltage electrodes with widths of 7.5 mm and a 17.5 mm gap between them. In comparison with the case without the electric field, with increasing the applied voltage to 30 kV, the efficiency of this EHD heat sink increases up to 37%.

Improvements in electrical equipment make them more compact with higher heat fluxes. Hence, the amount of heat to be dissipated per area increases and needs thermal management to operate at their design temperatures. Therefore, to improve the performance and life span of electronic components and increase their efficiency, it is necessary to design heat sinks to decrease their maximum (peak) temperature.

With development of the modern electronic and mechanical devices, cooling requirement has become a serious challenge. Innovative heat transfer enhancement methods are generally accompanied by undesirable increase of pressure drop and consequently a pumping power penalty. The current study aims to present a novel and easy method to manufacture a mini heat sink using porous fins and magnetite nanofluid (Fe₃O₄/water) as the coolant for simultaneous heat transfer enhancement and pressure drop reduction.

A three-dimensional numerical study is carried out to evaluate the thermal and hydrodynamic performance of the mini heat sink at different volume fractions, porosities and Reynolds numbers, using finite volume method. The solver specifications for discretization of the domain involve the SIMPLE, second-order upwind and second order for pressure, momentum and energy, respectively.

Results show that porous fins have a favorable effect on both heat transfer and pressure drop compared to solid fins. Creation of a virtual velocity slip on the channel-fin interfaces similar to the micro scale conditions and the flow permeation into the porous fins are the main mechanisms of pressure drop reduction. On the other hand, the heat transfer enhancement is attributed to the increase of the solid-fluid contact area and the improvement of the flow mixing because of the flow permeation into the porous fins. An optimal porosity for maximum convective heat transfer enhancement is obtained as a function of Reynolds number. However, taking both pressure drop and heat transfer effects into account, the overall heat sink performance is shown to be improved at high of Reynolds numbers, volume fractions and fin porosities.

Thermal radiation and gravity effects are ignored, and thermal equilibrium is assumed between solid and fluid phases.

A maximum of 32 per cent increase of convective heat transfer is achieved along with a maximum of 33 per cent reduction in the pressure drop using porous fins and ferrofluid in heat sink.

This study aims to satisfy the thermal management of gallium nitride (GaN) high-electron mobility transistor (HEMT) devices, microchannel-cooling is designed and optimized in this work.

A numerical simulation is performed to analyze the thermal and flow characteristics of microchannels in combination with computational fluid dynamics (CFD) and multi-objective evolutionary algorithm (MOEA) is used to optimize the microchannels parameters. The design variables include width and number of microchannels, and the optimization objectives are to minimize total thermal resistance and pressure drop under constant volumetric flow rate.

In optimization process, a decrease in pressure drop contributes to increase of thermal resistance leading to high junction temperature and vice versa. And the Pareto-optimal front, which is a trade-off curve between optimization objectives, is obtained by MOEA method. Finally, K-means clustering algorithm is carried out on Pareto-optimal front, and three representative points are proposed to verify the accuracy of the model.

Each design variable on the effect of two objectives and distribution of temperature is researched. The relationship between minimum thermal resistance and pressure drop is provided which can give some fundamental direction for microchannels design in GaN HEMT devices cooling.