18 research outputs found
Measurement of the W mass by direct reconstruction in collisions at 172 GeV
The mass of the W boson is obtained from reconstructed invariant mass distributions in W-pair events. The sample of W pairs is selected from 10.65~pb collected with the ALEPH detector at a mean centre-of-mass energy of 172.09 \GEV. The invariant mass distribution of simulated events are fitted to the experimental distributions and the following W masses are obtained: , , . The statistical errors are the expected errors for Monte Carlo samples of the same integrated luminosity as the data. The combination of these measurements gives:
Multilayer chitosan-based open tubular capillary anion exchange column with integrated monolithic capillary suppressor
China Scholarship Council; US National Science Foundation [CHE-0821969]; NASA [NNX11AO66G]We describe a multilayered open tubular anion exchange column fabricated by alternately pumping solutions of chitosan and glutaraldehyde. The column is terminated in an integrally bonded monolithic suppressor cast around a mandrel of a tungsten wire, composed of an acrylic acid (AA)-ethylene dimethacrylate (EDMA) monolith that is made with sufficient porogen for the monolith to function as a membrane. For a 4.5 m long 75 mu m bore column coated with 24 successive layers of the condensation polymer (estimated to contain similar to 72 molecular layers) and coupled to 1 cm length of a suppressor fabricated with 55-60% AA, effective separation of several common anions (F-, Cl-, NO2-, Br-, NO3-, average number of theoretical plates similar to 12,000) and adequate suppression of 1 mM KOH used as eluent was observed at a flow rate of 800 nL min(-1) to obtain sub-picomol detection limits at an operating pressure of similar to 1 bar. The separation is not time efficient but the system can be meritorious in unique niche applications where a small form factor is desired and liquid volume and power consumption are more important than separation speed. (C) 2011 Elsevier B.V. All rights reserved