Several of the fourteen rare-earth element (plus Sc and Y) orthophosphate standards grown at Oak Ridge National Laboratory in the 1980s and widely distributed by the Smithsonian Institution's Department of Mineral Sciences, are significantly contaminated by Pb. The origin of this impurity is the Pb2P2O7 flux that is derived from the thermal decomposition of PbHPO4. The lead pyrophosphate flux i...

Soil tillage practices have a profound influence on the physical properties of soil and the greenhouse gas (GHG) balance. However there have been very few integrated studies on the emission of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) and soil biophysical and chemical characteristics under different soil management systems. We recorded a significantly higher net global warming...

Measurement of greenhouse gas (GHG) fluxes between the soil and the atmosphere, in both managed and unmanaged ecosystems, is critical to understanding the biogeochemical drivers of climate change and to the development and evaluation of GHG mitigation strategies based on modulation of landscape management practices. The static chamber-based method described here is based on trapping gases emitt...

Performed analysis of the flux pinning on nano-sized centers, allowed to receive new results on the critical current problems in the high temperature oxide superconductors. A new model of the interaction pancake vortices with the nano-sized centers is proposed and comparison of obtained results with others pinning forces approaches is presented. The energy balance approach is applied, which lea...

Various inorganic membranes have demonstrated good capability to separate hydrogen from other gases at elevated temperatures. Hydrogen-permeable, dense, mixed proton-electron conducting ceramic oxides offer superior selectivity and thermal stability, but chemically robust candidates with higher ambipolar protonic and electronic conductivity are needed. In this work, we present for the first tim...

To accelerate the commercial application of mixed-conducting membrane reactor for catalytic reaction processes, a robust mixed-conducting multichannel hollow fiber (MCMHF) membrane reactor was constructed and characterized in this work. The MCMHF membrane based on reduction-tolerant and CO2-stable SrFe0.8Nb0.2O3-δ (SFN) oxide not only possesses a good mechanical strength, but also has a high ox...

An array of Pd-metal-oxide semiconductor (Pd-MOS) diodes has been used to monitor the fluence and energy of c~rge-exch~ge neutral hydrogen isotopes striking the wall of the Tokamak Fusion Test Reactor (TFTR). The array was positioned 4 cm behind the graphite-tiled waI1 at the toroidal midplane and exposed to several hundred plasma discharges. Hydrogen isotopes striking the Pd-MOS diodes were de...

It is highly desirable to reduce the membrane thickness in order to maximize the throughput and break the trade-off limitation for membrane-based gas separation. Two-dimensional membranes composed of atomic-thick graphene or graphene oxide nanosheets have gas transport pathways that are at least three orders of magnitude higher than the membrane thickness, leading to reduced gas permeation flux...

To develop an effective process for tantalum powder production, a new preform reduction process (PRP) based on the magnesiothermic reduction of feed preform containing tantalum oxide (Ta2O5) was investigated. The feed preformwas fabricated from slurry, which was made by mixing Ta2O5 powder, flux (e.g., CaCl2), and binder. Various compositions of preform in the form of plates were prepared using...

A mixed-conducting multichannel hollow fiber membrane (MCMHF) based on CO2-tolerant SrFe0.8Nb0.2O3–δ (SFN) oxide has been successfully prepared by phase inversion and sintering technique. The morphology, breaking load, oxygen permeability under CO2 atmosphere, thermal cycling performance and the long-term stability of the membrane were investigated in detail. The prepared membrane has a signifi...