Improving mechanical properties and sustainability of high-strength engineered cementitious composites (ECC) using diatomite

High-strength engineered cementitious composites (ECC) typically require higher cement content, which is negative from the sustainability point of view. To alleviate this problem, herein a low-cost and eco-friendly high-strength ECC (with a compressive strength of over 100 MPa) was developed, and diatomite was used to replace a small amount...

RAST: Risk-Aware Spatio-Temporal Safety Corridors for MAV Navigation in Dynamic Uncertain Environments

Autonomous navigation of Micro Aerial Vehicles (MAVs) in dynamic and unknown environments is a complex and challenging task. Current works rely on assumptions to solve the problem. The MAV's pose is precisely known, the dynamic obstacles can be explicitly segmented from static ones, their number is known and fixed, or they can be modeled with...

A Mode-Switching Based Phase Shift Control for Optimized Efficiency and Wide ZVS Operations in Wireless Power Transfer Systems

This article proposes a mode-switching-based phase shift control (MS-PSC) for wireless power transfer (WPT) systems, which is able to achieve power regulation, load matching, and wide ZVS operations simultaneously without using additional dc-dc converters. Based on the mode transitions between the full-bridge, mixed-bridge, and half-bridge...

Exploring Decision-Making Complexity in Major Infrastructure Projects: A Case Study From China

The goal of this study is to identify, classify, explore, and understand decision-making complexity elements in major infrastructure projects (MIPs). This article puts forward systematic definitions of decision making, decision-making quality, and decision-making complexity. Based on literature reviews and an in-depth case analysis of Hong...

Contractor cooperation mechanism and evolution of the green supply chain in mega projects

The large scale of construction in mega projects leads to significant environmental and socioeconomic impacts; thus, the projects should also exhibit greater social responsibility. Adopting green supply chain management in the construction process is an important way to realize the goal of sustainable development of mega projects. Because the...

Achieving economically sustainable subcontracting through the hotelling model by considering the spillover effect

In the process of internationalization of construction contractors, international enterprises as main contractors (IMC) need to consider whether part of the contract should be subcontracted to local subcontractors (LSC) to gain a competitive advantage when competing with local main contractors (LMC). The involvement of local subcontractors...

Incentive mechanism of prefabrication in mega projects with reputational concerns

As one of the most important sustainability project management practices, prefabrication has been drawing increasing attention to project construction practitioners. However, due to the needs of high technology and large capital investment, there is a great challenge for suppliers to adopt prefabrication in mega project construction....

Erosion potential of the Yangtze Delta under sediment starvation and climate change

Deltas are widely threatened by sediment starvation and climate change. Erosion potential is an important indicator of delta vulnerability. Here, we investigate the erosion potential of the Yangtze Delta. We found that over the past half century the Yangtze's sediment discharge has decreased by 80% due to the construction of >50,000 dams...

A plasmonic spanner for metal particle manipulation

Typically, metal particles are difficult to manipulate with conventional optical vortex (OV) tweezers, because of their strong absorption and scattering. However, it has been shown that the vortex field of surface plasmonic polaritons, called plasmonic vortex (PV), is capable of stable trapping and dynamic rotation of metal particles, especially...

Risk analysis on cascade breaching of the Tangjiashan landslide dam and two smaller downstream landslide dams

The 2008 Mw 7.9 Wenchuan earthquake triggered at least 257 landslide dams, most of which formed in series along rivers. The failure of an upstream dam could cause the failure of dams downstream one after another. The cascade dam breaching may result in sharp increase of flood and more serious damage downstream. This paper aims to analyze the...