Chemo-physical characterization and molecular dynamics simulation of long-term aging behaviors of bitumen

To further explore the long-term aging behaviors of bitumen from the multiscale perspectives, the experimental characterization and molecular dynamics (MD) simulation methods were performed. Series of chemical properties for the virgin and various aged bitumen were evaluated using the TCL-FID, ATR-FTIR, Elemental analysis and GPC tests. The...

The continuous swelling-degradation behaviors and chemo-rheological properties of waste crumb rubber modified bitumen considering the effect of rubber size

The chemo-rheological properties of crumb rubber modified bitumen are always unstable due to the mutable and uncontrollable swelling-degradation degree of crumb rubber in bitumen matrix. The study aimed at exploring the continuous swelling and degradation behaviors of crumb rubber modified bitumen (CRMB) considering the influence of rubber size...

Investigating the role of swelling-degradation degree of crumb rubber on CR/SBS modified porous asphalt binder and mixture

Porous asphalt pavement is widely used due to its adequate water permeability, noise reduction and skid resistance. The study aims at exploring the potential of using the crumb rubber/styrene–butadienestyrene (CR/SBS) modified bitumen as high-viscosity binder for porous asphalt mixture, and investigating the effect of swelling and degradation...

Use of waste oil/styrene-butadiene-rubber blends as rejuvenators for aged bitumen

This study elaborates the influence of blends formulated by waste oil (WO) and styrene-butadiene rubber (SBR) on thermo-mechanical and chemical compositional characteristics of rejuvenated bitumen. The results show that both WEO (waste engine oil) and WCO (waste cooking oil) can compensate viscous component for reclaimed bitumen, and the effect...

ESEM observation and rheological analysis of rejuvenated SBS modified bitumen

Observing the microstructure of bituminous binders with an environmental scanning electron microscope (ESEM) can contribute significantly to reveal the underlying rejuvenation mechanism. In this study, three rejuvenators were selected to regenerate the aged SBS modified binders at five dosages, and their rheology was evaluated using a dynamic...

Multi-scale characterization of lignin modified bitumen using experimental and molecular dynamics simulation methods

Lignin, as a major waste from biofuel and paper industries, could be utilized as a modifier to enhance the relevant performance of bitumen. However, the effects of lignin on the thermodynamics properties and molecular structure of bitumen are rarely studied. Meanwhile, the potential modification mechanism of lignin modified bitumen is still...

Mechanical Parameter Identification of Hydraulic Engineering with the Improved Deep Q-Network Algorithm

During the long-term operating period, the mechanical parameters of hydraulic structures and foundation deteriorated gradually because of the environmental factors. In order to evaluate the overall safety and durability, these parameters should be calculated by some accurate analysis methods, which are hindered by slow computational...

Laboratory evaluation of the effects of long-term aging on high content polymer modified asphalt binder

One of the most widely used polymer-based modifiers in asphalt binders is styrene–butadiene–styrene (SBS), which results in binders of increased modulus, strength, toughness, and resistance to permanent deformation. These properties are further improved with the increase of SBS polymer content in asphalt binders, producing binders such as high...

Microchannel Thermal Management System with Two-Phase Flow for Power Electronics over 500 W/cm²Heat Dissipation

In this article, a microchannel thermal management system (MTMS) with the two-phase flow using the refrigerant R1234yf with low global warming potential is presented. The thermal test vehicles (TTVs) were made of either single or multiple thermal test chips embedded in the substrates, which were then attached to the MTMS. The system included...

Improved aerosol correction for OMI tropospheric NO2 retrieval over East Asia: Constraint from CALIOP aerosol vertical profile

Satellite retrieval of vertical column densities (VCDs) of tropospheric nitrogen dioxide (NO₂) is critical for NO_x pollution and impact evaluation. For regions with high aerosol loadings, the retrieval accuracy is greatly affected by whether aerosol optical effects are treated implicitly (as additional effective clouds)...

Insight into Eu redox and Pr³⁺ 5d emission in KSrPO₄ by VRBE scheme construction

A series of Ln-doped KSrPO₄ (Ln = Ce³⁺, Eu³⁺, Eu²⁺, Pr³⁺) phosphors are prepared through a high-temperature solid-state method. The KSrPO₄ compound is confirmed to possess a β-K₂SO₄ structure with the Pnma group by Rietveld refinement, and the temperature...

Generating sparse self-supporting wireframe models for 3D printing using mesh simplification

Wireframe models are becoming a popular option in 3D printing. Generating sparse wireframe models using classic mesh simplification methods leads to models that require a lot of support structures in the layer-upon-layer additive process. In this paper we present a mesh simplification method that takes into account the overhang angle....

A 0.6V 3.8μW ECG/bio-impedance monitoring IC for disposable health patch in 40nm CMOS

Simultaneous measurement of Electrocardiogram (ECG) and bio-impedance (BioZ) via disposable health patches is desired for patients suffering from chronic cardiovascular and respiratory diseases. However, a sensing IC must consume ultra-low power under a sub-volt supply to comply with miniaturized and disposable batteries. This work presents...

Hydrologic and cryospheric processes observed from space

Ten Dragon 3 projects deal with hydrologic and cryosphere processes, with a focus on the Himalayas and Qinghai – Tibet Plateau, but not limited to that. At the 1st Dragon 3 Progress Symposium in 2013 a significant potential for a better and deeper integration appeared very clearly and we worked out an overview of the ten projects identifying...

Comparison of drift velocities of nighttime equatorial plasma depletions with ambient plasma drifts and thermospheric neutral winds

This is the first study to compare plasma depletion drifts with the ambient plasma drifts and neutral winds in the post sunset equatorial ionosphere using global-scale satellite observations. The local time and latitude variations of the drift velocities of O+ plasma depletions at 350–400?km altitude are derived from the observations of the far...