1,044 research outputs found
Local solid-state modification of nanopore surface charges
The last decade, nanopores have emerged as a new and interesting tool for the
study of biological macromolecules like proteins and DNA. While biological
pores, especially alpha-hemolysin, have been promising for the detection of
DNA, their poor chemical stability limits their use. For this reason,
researchers are trying to mimic their behaviour using more stable, solid-state
nanopores. The most successful tools to fabricate such nanopores use high
energy electron or ions beams to drill or reshape holes in very thin membranes.
While the resolution of these methods can be very good, they require tools that
are not commonly available and tend to damage and charge the nanopore surface.
In this work, we show nanopores that have been fabricated using standard
micromachning techniques together with EBID, and present a simple model that is
used to estimate the surface charge. The results show that EBID with a silicon
oxide precursor can be used to tune the nanopore surface and that the surface
charge is stable over a wide range of concentrations.Comment: 10 pages, 6 figure
Elevated levels of adhesion molecules in septic patients with pre-existing coronary artery disease
âVechten met het levenâ:Een kwalitatief onderzoek onder ongedocumenteerde oudere migranten in Nederland
âVechten met het levenâ:Een kwalitatief onderzoek onder ongedocumenteerde oudere migranten in Nederland
Results from the test bench of the Geometry Monitoring System of the ALICE Muon Spectrometer
We present the results obtained with the test bench of the Geometry Monitoring System (GMS) for the ALICE Muon Spectrometer. It consists in a mock up, reproducing at full scale, three half planes of the chambers 6, 7 and 8 of the spectrometer. We show that the GMS is able to measure transverse displacements with an accuracy of 1.5 microm. We show also that the resolution deteriorates by a factor 3 to 4 when thermal gradients are generated
Ruthenium PNN(O) Complexes: Cooperative Reactivity and Application as Catalysts for Acceptorless Dehydrogenative Coupling Reactions
How Population Structure Impacts Genomic Selection Accuracy in Cross-Validation:Implications for Practical Breeding
G Electronics and Data Acquisition (Forward-Angle Measurements)
The G parity-violation experiment at Jefferson Lab (Newport News, VA) is
designed to determine the contribution of strange/anti-strange quark pairs to
the intrinsic properties of the proton. In the forward-angle part of the
experiment, the asymmetry in the cross section was measured for
elastic scattering by counting the recoil protons corresponding to the two
beam-helicity states. Due to the high accuracy required on the asymmetry, the
G experiment was based on a custom experimental setup with its own
associated electronics and data acquisition (DAQ) system. Highly specialized
time-encoding electronics provided time-of-flight spectra for each detector for
each helicity state. More conventional electronics was used for monitoring
(mainly FastBus). The time-encoding electronics and the DAQ system have been
designed to handle events at a mean rate of 2 MHz per detector with low
deadtime and to minimize helicity-correlated systematic errors. In this paper,
we outline the general architecture and the main features of the electronics
and the DAQ system dedicated to G forward-angle measurements.Comment: 35 pages. 17 figures. This article is to be submitted to NIM section
A. It has been written with Latex using \documentclass{elsart}. Nuclear
Instruments and Methods in Physics Research Section A: Accelerators,
Spectrometers, Detectors and Associated Equipment In Press (2007
Projectile fragmentation of 129Xe at Elab=790 AMeV
We have measured production yields and longitudinal momentum distributions of
projectile-like fragments in the reaction 129Xe + 27Al at an energy of Elab=790
AMeV. Production cross sections higher than expected from systematics were
observed for nuclei in the neutron-deficient tails of the isotopic
distributions. A comparison with previously measured data from the
fragmentation of 136Xe ions shows that the production yields strongly depend on
the neutron excess of the projectile with respect to the line of
beta-stability. The momentum distributions exhibit a dependence on the fragment
neutron-to-proton ratio in isobaric chains, which was not expected from
systematics so far. This can be interpreted by a higher excitation of the
projectile during the formation of neutron-deficient fragments.Comment: 21 pages, 8 figures, 1 tabl
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