Measuring Trace Level Constituents with SEM/SDD-EDS

Trace constituents of Europa’s atmosphere

Predictions for Other Trace Constituents

The Geophysical Fluid Dynamics Laboratory (GFDL) three-dimensional general circulation/tracer model has been used to investigate the stratospheric behavior of N20 under a range of photodestruction hypotheses. A comparison of observations with these simulations shows that the atmospheric N20 lifetime lies between 100 and 130 years. For the three experiments conducted, it was found that the model...

Trace Element Analysis in Geochemical Systems by STEM/EDS

Until recently, measurement of trace elements with ppm concentrations has been inaccessible to STEM EDS. Development of fast SDD detectors with solid angles > 1/2 steradian and faster processors are now making such measurements a reality. STEM EDS measurements already have a low brehmsstrahlung background owing to thin samples. However, the combination of high beam currents required to attain s...

Trace-Level Reuse

Trace-level reuse is based on the observation that some traces (dynamic sequences of instructions) are frequently repeated during the execution of a program, and in many cases, the instructions that make up such traces have the same source operand values. The execution of such traces will obviously produce the same outcome and thus, their execution can be skipped if the processor records the ou...

Sorption of Trace Constituents from Aqueous Solutions onto Secondary Minerals

-Well-characterized American Petroleum Institute clay standards, source clays from The Clay Minerals Society, and other secondary minerals were used to determine the effects of U concentration, temperature, and solution composition on U-sorption properties. Uranium concentrations ranged from about 1.00 x 10 -4 M to 4.00 x 10 7 M, temperatures from 5 ~ to 65~ and solution compositions containing...