Photoluminescence from Radiative Surface States and Excitons in Methylammonium Lead Bromide Perovskites

In view of its band gap of 2.2 eV and its stability, methylammonium lead bromide (MAPbBr₃) is a possible candidate to serve as a light absorber in a subcell of a multijunction solar cell. Using complementary temperature-dependent time-resolved microwave conductance (TRMC) and photoluminescence (TRPL) measurements, we demonstrate...

Investigation of drying-induced non-uniform deformation, stress, and micro-crack propagation in concrete

Concrete generally deforms and cracks in a non-uniform manner under drying-induced stress. This study used the lattice fracture model to simulate the drying-induced non-uniform deformations, stresses, and micro-crack propagation in concrete. Experiments were designed to validate the lattice fracture model, wherein the drying-induced non...

Effect of relative humidity on drying-induced damage in concrete: A comparative study of digital image correlation and lattice modelling

To assess the effect of relative humidity (RH) on drying-induced damage in concrete, the non-uniform strains and microcracks in concrete under different RH conditions were obtained using the digital image correlation (DIC) technique and lattice fracture model. The simulated non-uniform displacements were consistent with those captured using...

Effect of coarse aggregate size on non-uniform stress/strain and drying-induced microcracking in concrete

Non-uniform stresses, strains and microcracking of the concretes with three coarse aggregate sizes (5–10 mm, 10–16 mm, 16–20 mm) dried under 40% relative humidity (RH) for 60 days were quantified using digital image correlation and lattice fracture modelling. The influencing mechanism of coarse aggregate size on the drying-induced...

Reactions of self-healing agents and the chemical binding of aggressive ions in sea water: Thermodynamics and kinetics

New self-healing agents that can chemically bind seawater ions invading cracked cementitious materials were proposed. The potential of self-healing and binding of seawater ions were investigated by thermodynamic modeling. It was found that CaO-NaAlO₂ and CaO-metakaolin agents can have Cl⁻, SO₄²⁻ and...

Thermodynamic modelling of the reactions of self-healing agents and the chemical binding of aggressive ions in seawater

In this study, a new concept on self healing of cracks that the ingressive ions in the crack is chemically bound to improve the self-healing efficiency was proposed for cracked cementitious materials in a marine environment. Thermodynamic modeling was performed to determine the appropriate masses and ratio of Ca2+ and Al3+ provided by chemical...

The influence of lightweight functional aggregates on the acidification damage in the external anode mortar during cathodic protection for reinforced concrete

Impressed current cathodic protection (ICCP) is an effective corrosion protection and prevention technique for reinforced concrete structures served in chloride-contaminated environment. The acidification damage in the external anode mortar caused by the anodic reactions significantly influences the efficiency of ICCP for reinforced concrete....

Incorporating elastic and creep deformations in modelling the three-dimensional autogenous shrinkage of cement paste

A structure-based modelling framework was established to simulate the three-dimensional autogenous shrinkage of cement paste. A cement hydration model, HYMOSTRUC3D-E, was used to obtain the microstructures and ionic concentrations of the cement paste. A lattice fracture model based on the effective stress and effective modulus was used to...

A 76.5-92.6 GHz CMOS LNA Using Two-Port kQ-Product Theory for Transformer Design

This letter presents a convenient approach based on the two-port kQ-product theory to analyze the influence of interwinding capacitive coupling on the efficiency of the transformer. It is demonstrated that a transformer with proper size can benefit from the interwinding capacitive coupling to maximize its efficiency at a desired frequency....

Bilevel Model for Protection-Branch Measurements-Based Topology Attack Against DC and AC State Estimations

A topology attack, as a special class of false data injection attacks, tampers with topology information of a system to mislead the decision of the control center. This article conducts an in-depth study on topology attacks that aim to interfere with the judgment in topology information and pose potential damage by tampering with measurement...

Unveiling the inequalities in virtual water transfer in China: The environmental and economic perspectives

To alleviate the geographical mismatch between supply and demand of water resources, virtual water trade had attracted extensive attention. Many studies had estimated the virtual water flow and measured the virtual water inequality using Environmental Input-Output (EIO) model. However, EIO model ignores the feedback effect in the trade, which...