Response surface methodology box-behnken design to optimise the hydrothermal synthesis of gadolinium nanoparticles

Gadolinium (Gd) nanoparticles (NPs) are increasingly considered as a viable alternative to clinically employed Gd chelates in magnetic resonance imaging (MRI). The utilisation of these materials as contrast agents offers several advantages including lower toxicity, prolonged circulation time, and a sufficiently high Gd content, thereby...

Experimental and numerical study on lateral resistance of frictional sleeper with arrowhead groove

To enhance the stability of continuous welded rail (CWR) tracks, frictional sleepers have been developed. The frictional sleepers are new types of sleepers with grooves on the bottom, and different bottom grooves improve lateral resistances at different magnitudes. In this study, single sleeper push test (SSPT) and its model with discrete...

Rheology study of ballast-sleeper interaction with particle image Velocimetry (PIV) and discrete element modelling (DEM)

Ballast rheology is a phenomenon that describes movements of ballast particles due to the discrete nature, which eventually leads to the ballast bed fluid deformation after a long-time service. In most cases, ballast rheology is the main reason of track irregularity that leads to some track defects, e.g., hanging sleeper and mud spots....

Glacier mass balance in the Nyainqentanglha mountains between 2000 and 2017 retrieved from ZiYuan-3 stereo images and the SRTM DEM

Mountain glaciers are excellent indicators of climate change and have an important role in the terrestrial water cycle and food security in many parts of the world. Glaciers are the major water source of rivers and lakes in the Nyainqentanglha Mountains (NM) region, where the glacier area has the second largest extent on the Tibetan Plateau....

Lateral resistance of polyurethane-reinforced ballast with the application of new bonding schemes: Laboratory tests and discrete element simulations

To mitigate the ballast flight risk in the high-speed railway, this paper presents three new polyurethane bonding schemes which have negligible influence to tamping operations. With the application of these bonding schemes, a series of laboratory tests indicated that the polyurethane-reinforced ballast exhibited much larger lateral resistance...

Experimental and numerical investigations on the shear behaviour of recycled railway ballast

Ballast degradation is frequently observed under cyclic loading, and results in bearing capacity and drainage problem of ballast track. To keep the stability and safety, periodical maintenances are needed, such as cleaning and replacement, which produce a huge amount of wasted ballast. Thus, reusing the deteriorated ballast can become a...

Filtering the NPP-VIIRS nighttime light data for improved detection of settlements in Africa

Observing and understanding changes in Africa is a hotspot in global ecological environmental research since the early 1970s. As possible causes of environmental degradation, frequent droughts and human activities attracted wide attention. Remote sensing of nighttime light provides an effective way to map human activities and assess their...

Interface Investigation of Core-annular Flow

The transport of highly-viscous oil in the core-annular flow regime in a horizontal pipe is investigated with a numerical simulation study. In this flow type the viscous oil is lubricated by a water annulus along the pipe wall. The Launder-Sharma low-Reynolds number k-ε turbulence model is used with the Volume-of-Fluid solver in interFOAM. Three...

A new method to estimate changes in glacier surface elevation based on polynomial fitting of sparse ICESat—GLAS footprints

We present in this paper a polynomial fitting method applicable to segments of footprints measured by the Geoscience Laser Altimeter System (GLAS) to estimate glacier thickness change. Our modification makes the method applicable to complex topography, such as a large mountain glacier. After a full analysis of the planar fitting method to...