No abstract

A system for' producing 300 us bursts ofi lo1' metal atoms. with 3 'eV .average. energy is described. It is shown that.'-th'i's. system can be successfully used to introduce impurities'into '... .. . : : CTR oriented tokamaks for transport. and con£ inement studi'es .-. .

The limited flux and selectivities of current carbon dioxide membranes and the high costs associated with conventional absorption-based CO2 sequestration call for alternative CO2 separation approaches. Here we describe an enzymatically active, ultra-thin, biomimetic membrane enabling CO2 capture and separation under ambient pressure and temperature conditions. The membrane comprises a ~18-nm-thick close-packed array of 8 nm diameter hydrophilic pores that stabilize water by capillary condensation and precisely accommodate the metalloenzyme carbonic anhydrase (CA). CA catalyzes the rapid interconversion of CO2 and water into carbonic acid. By minimizing diffusional constraints, stabilizing and concentrating CA within the nanopore array to a concentration 10× greater than achievable in solution, our enzymatic liquid membrane separates CO2 at room temperature and atmospheric pressure at a rate of 2600 GPU with CO2/N2 and CO2/H2 selectivities as high as 788 and 1500, respectively, the highest combined flux and selectivity yet reported for ambient condition operation.

On a porous substrate, regular atomic layer deposition (ALD) not only takes place on top of the substrate but also penetrates into the internal porosity. Here we report a plasma-assisted process in which the ALD precursors are chosen to be non-reactive unless triggered by plasma, so that ALD can be spatially defined by the supply of plasma irradiation. Since plasma cannot penetrate within the internal porosity, ALD has been successfully confined to the immediate surface. This not only gives a possible solution for sealing of porous low dielectric constant films with a conformal layer of nm-scale thickness, but also enables us to progressively reduce the pore size of mesoporous materials in a sub-Å/cycle fashion for membrane formation.As device dimensions in semiconductor integrated circuits (ICs) continue to shrink, low dielectric constant (low-k) materials are needed as interlevel dielectrics (ILD) to mitigate issues caused by reduced line widths and line-to-line spacings such as increasing RC-delay. To satisfy the technical requirements established by the microelectronics roadmap (where k values < 2 are ultimately specified), future generation ILD materials must incorporate porosity. However, the pores, typically on the order of angstroms to a few nanometers and interconnected at elevated porosities, can trap moisture, gas precursors and other contaminants in subsequent