Synthesis, solubility and thermodynamic properties of N-A-S-H gels with various target Si/Al ratios

The synthesis of N-A-S-H gel with high Si/Al ratios (>2) has been rarely reported in the literature, leaving the establishment of a reliable synthesis route as an open challenge. This paper aims to synthesize N-A-S-H gels with Si/Al ratios ranging from 1 to 3 and establish their thermodynamic database. The effects of reaction temperature,...

Modeling dynamic stall of an airfoil with vortex generators using a double-wake panel model with viscous–inviscid interaction

Vortex generators (VGs) have been widely applied to wind turbines thanks to their potential to increase aerodynamic performance. Due to the complex inflow perceived by a rotor and the proneness to flow separation, VGs on wind turbines usually experience highly unsteady flow. While there are models that exist to simulate the steady effects of...

Stability Analysis of Triple Active Bridge Converter with Hybrid Loads and Different Control Strategies

This article investigates the stability of triple active bridge (TAB) converter with different types of loads. In this paper, port2 of TAB converter adopts voltage control to supply a constant power load (CPL), and port3 uses voltage control to supply a resistor or uses current control to supply a battery. Then, an extra element theorem-based ...

A soft start-up method for DC micro-grid based on improved two-level VSC with DC fault ride-through capability

For the black start-up of DC micro-grids, three-phase charging resistors are required to limit the uncontrollable surge current. The main drawback of this start-up method is the difficulty in determining the appropriate resistance value to achieve a rapid start-up and limit the surge current with the change of grid parameters. To address this...

Efficient Variational Bayes Learning of Graphical Models with Smooth Structural Changes

Estimating a sequence of dynamic undirected graphical models, in which adjacent graphs share similar structures, is of paramount importance in various social, financial, biological, and engineering systems, since the evolution of such networks can be utilized for example to spot trends, detect anomalies, predict vulnerability, and evaluate...

Prediction of River Pollution Under the Rainfall-Runoff Impact by Artificial Neural Network: A Case Study of Shiyan River, Shenzhen, China

Climate change and rapid urbanization have made it difficult to predict the risk of pollution in cities under different types of rainfall. In this study, a data-driven approach to quantify the effects of rainfall characteristics on river pollution was proposed and applied in a case study of Shiyan River, Shenzhen, China. The results indicate...

Safety Performance Boundary Identification of Highly Automated Vehicles: A Surrogate Model-Based Gradient Descent Searching Approach

Highly automated vehicles (HAVs) have been introduced to the transportation system for the purpose of providing safer mobility. Considering the expected long co-existence period of HAVs and human-driven vehicles (HDVs), the safety operation of HAVs interacting with HDVs needs to be verified. To achieve this, HAVs' Operational Design Domain ...

On capturing human agency and methodological interdisciplinarity in socio-hydrology research

Socio-hydrology has expanded and been effective in exposing the hydrological community to ideas and approaches from other scientific disciplines, and social sciences in particular. Yet it still has much to explore regarding how to capture human agency and how to combine different methods and disciplinary views from both the hydrological and...

Assessing sponge cities performance at city scale using remotely sensed LULC changes: Case study Nanjing

As a result of high-density urbanization and climate change, both the frequency and intensity of extreme urban rainfall are increasing. Drainage systems are not designed to cope with this increase, and as a result, floods are becoming more common in cities, particularly in the rapidly growing cities of China. To better cope with more frequent...

A first step towards computational design of W-containing self-healing ferritic creep resistant steels

In this work, we combine a generic alloy-by-design model with a novel concept, the nucleation barrier for the formation of Laves phase to fill the creep cavities, in order to develop multi-component creep resistant steels with kinetically tuned self-healing behaviour. In the model the high-temperature long-term strength is estimated by...

From sequentially linear analysis to incremental sequentially linear analysis: Robust algorithms for solving the non-linear equations of structures of quasi-brittle materials

It is difficult to accurately predict the strength of masonry and concrete structures. The most widely used method for simulating their behaviour is finite element analysis with the Newton-Raphson method and arch length control. However, the Newton-Raphson method can diverge and not produce a result, for example in bifurcations or during snap...

Incremental sequentially linear analysis to control failure for quasi-brittle materials and structures including non-proportional loading

Quasi brittle materials, such as un-reinforced masonry or concrete are difficult to analyse because often the traditional Newton–Raphson (N-R) procedure fails to converge. Many solutions have been proposed such as Sequentially Linear Analysis (SLA), but these may fail in case of non-proportional loading with a large prestress. In this paper a...

Analytical and Simulation Study of Sweep Efficiency in Gas-Injection EOR

WAG (Water-Alternating-Gas injection) is a non-thermal EOR process, which was proposed to improve the volumetric sweep efficiency and consequently the oil recovery during a gas injection project. Though miscible gas injection gives fantastic displacement efficiency due to its miscibility with oil, it usually shows very poor volumetric sweep...

On the Refraction of Shock Waves at Fe-Be Interface

The paper aims to investigate the refraction phenomena of shock waves at ferrum-beryllium (Fe-Be) interface. The equations of state of Fe and Be adopt “stiffen gas” formula. For the regular refraction, the shock polar theory is employed. The critical angles of transition of the regular to irregular refraction about the different shock intensity...