Characterizing the Effects of Al(OH)3 and Mg(OH)2 on Reaction Products and Drying Shrinkage Characteristics of Alkali-activated Slag

This study is undertaken to explore the relationship between the reaction products and the drying shrinkage of alkali-activated slag (AAS) with the varying hydroxide dosage. AAS pastes were firstly produced with either Al(OH)3 or Mg(OH)2 to investigate the effects of hydroxide on the composition of reaction products and the drying shrinkage of...

The Effect of Wet Treatment on the Distribution and Leaching of Heavy Metals and Salts of Bottom Ash from Municipal Solid Waste Incineration

One of the main challenges of bottom ash reutilization is heavy metal and salts' leaching potential. The effect of wet treatment on chemical composition and leaching toxicity of bottom ash were investigated in this study to mitigate this leaching potential. Batch leaching and column leaching tests were first conducted to investigate the...

Quantification of the influencing factors for flood peak discharge increase in the Lower Yellow River

The past decades have witnessed frequent flood peak discharges increase in the Lower Yellow River (LYR). Yet no consensus for its mechanism has been achieved. Here 21 events of the peak discharge increase (PDI) in the period of 1973–2012 are analysed. It is shown that the mean increment of peak discharge increases from 810 m³/s to...

Research progress on geosynchronous synthetic aperture radar

Based on its ability to obtain two-dimensional (2D) high-resolution images in all-time and all-weather conditions, spaceborne synthetic aperture radar (SAR) has become an important remote sensing technique and the study of such systems has entered a period of vigorous development. Advanced imaging modes such as radar interferometry,...

Study on the aging resistance of polyurethane precursor modified bitumen and its mechanism

As an environmentally friendly alternative for the production of high-performance modified asphalt by chemical reactions, a liquid-state polyurethane-precursor-based reactive modifier (PRM) was developed and employed in the asphalt modification. In contrast to the traditional solid bitumen modifier, for example, rubber and thermoplastic...

Laboratory data on wave propagation through vegetation with following and opposing currents

Coastal vegetation has been increasingly recognized as an effective buffer against wind waves. Recent laboratory studies have considered realistic vegetation traits and hydrodynamic conditions, which advanced our understanding of the wave dissipation process in vegetation (WDV) in field conditions. In intertidal environments, waves commonly...

New innovations in pavement materials and engineering: A review on pavement engineering research 2021

Sustainable and resilient pavement infrastructure is critical for current economic and environmental challenges. In the past 10 years, the pavement infrastructure strongly supports the rapid development of the global social economy. New theories, new methods, new technologies and new materials related to pavement engineering are emerging....

Moving Target Detection and Parameter Estimation via a Modified Imaging STAP with a Large Baseline in Multistatic GEO SAR

With the development trends of multistatic spaceborne synthetic aperture radar (SAR), geosynchronous SAR (GEO SAR) employing several formation-flying small satellites also has great potential for remote sensing. The small satellites can cooperate to acquire multi-channel data for moving target detection and parameter estimation in strong...

Formation design for single-pass GEO InSAR considering earth rotation based on coordinate rotational transformation

The single-pass geosynchronous synthetic aperture radar interferometry (GEO InSAR) adopts the formation of a slave satellite accompanying the master satellite, which can reduce the temporal decorrelation caused by atmospheric disturbance and observation time gap between repeated tracks. Current formation design methods for spaceborne SAR are...

Geosynchronous spaceborne-airborne bistatic moving target indication system: Performance analysis and configuration design

Geosynchronous spaceborne-airborne bistatic synthetic aperture radar (GEO SA-BSAR), consisting of GEO transmitter and airborne receiver, has stable coverage for a long time and benefits moving target detection. However, the performance of GEO SA-BSAR moving target indication (MTI) system varies widely between bistatic configurations. The...

Hypericin: Source, Determination, Separation, and Properties

Hypericin is a naturally occurring compound synthesized by certain species of the genus Hypericum, with various pharmacological effects. It is used as a natural photosensitizing agent with great potential in photodynamic therapy. This review discusses the latest results about the biosynthetic pathways and chemical synthetic routes to obtain...

Modeling and Analyzing Impacts of Drifting Anisotropic Ionospheric Irregularities on Inclined Geosynchronous SAR

The sub-satellite track of geosynchronous synthetic aperture radar (GEO SAR) presents the figure "8" or "O", which causes the great changes of platform motion direction and the different projection of anisotropic irregularities along the line-of-sight (LOS) direction. Due to the almost equal angle velocity to that of Earth, the GEO SAR has...

Modeling and quantitative analysis of tropospheric impact on inclined geosynchronous SAR imaging

Geosynchronous orbit synthetic aperture radar (GEO SAR) has a long integration time and a large imaging scene. Therefore, various nonideal factors are easily accumulated, introducing phase errors and degrading the imaging quality. Within the long integration time, tropospheric status changes with time and space, which will result in image shifts...

Deriving vegetation drag coefficients in combined wave-current flows by calibration and direct measurement methods

Coastal vegetation is efficient in damping incident waves even in storm events, thus providing valuable protections to coastal communities. However, large uncertainties lie in determining vegetation drag coefficients (C_D), which are directly related to the wave damping capacity of a certain vegetated area. One major uncertainty is...

Size and Topology Optimization for Trusses with Discrete Design Variables by Improved Firefly Algorithm

Firefly Algorithm (FA, for short) is inspired by the social behavior of fireflies and their phenomenon of bioluminescent communication. Based on the fundamentals of FA, two improved strategies are proposed to conduct size and topology optimization for trusses with discrete design variables. Firstly, development of structural topology...

Assessment of Water Use in Pan-Eurasian and African Continents by ETMonitor with Multi-Source Satellite Data

The Pan-Eurasian and African Continents are characterized by large ranges of climates varying from humid, semi-humid, semi-arid and arid regions, and great challenges exist in water allocation for different sectors that related to water resource and food security, which depends strongly on the water use information. Quantitative information...

A New Quantitative Method for Studying the Vulnerability of Civil Aviation Network System to Spatially Localized Hazards

As an important infrastructure system, civil aviation network system can be severely affected by natural hazards. Although a natural hazard is usually local, its impact, through the network topology, can become global. Inspired by Wilkinson’s work in 2012, this article proposes a new quantitative spatial vulnerability model for network...