Atomically flat and clean metal surfaces exhibit a regime of ultra-low friction at low normal loads. Atomic force microscopy, performed in ultra-high vacuum on Cu(100) and Au(111) surfaces, reveals a clear stick-slip modulation in the lateral force but almost zero dissipation. Significant friction is observed only for higher loads (*4– 6 nN above the pull-off force) together with the onset of w...

A novel technique has been developed to build vessels for liquid xenon ionization detectors entirely out of ultra-clean fluoropolymer. We describe the advantages in terms of low radioactivity contamination, provide some details of the construction techniques, and show the energy resolution achieved with a prototype all-fluoropolymer ionization detector.

Many modern analytical methods deal with the trace-level determination of compounds of interest in highly complex environmental samples by means of chromatographic techniques. The introduction of a “clean” sample into an analytical instrument can make analyses easier and prolongs the equipment life. The use of solid-phase extraction (SPE) has grown and is a fertile technique of sample prepa...

Methane adsorption properties of coal are essential for coalbed methane (CBM) extraction and clean energy utilization. However, the effect nanopores on CH4 in high volatile bituminous...

—This paper addresses the problem of the roadway environment and Non-Line of Sight (NLOS) propagation on localization accuracy in coal mine. Unlike prior localization algorithms, reference nodes are deployed according to the actual environment in coal mine, and Time-of-Arrival (TOA) and Receive Signal Strength (RSS) measurements using UltraWideband (UWB) signals are combined to obtain better l...

This study focused on the evaluation of the machinability of different carburising steel grades by using a cemented carbide cutting tool during semi finishing of steel. The effect of the steel composition, microstructure and inclusion characteristics on the cutting tool wear in the soft part turning was evaluated for a reference steel R (0.028% S, 0.0009% O), a clean C steel (0.003% S, 0.0005% ...