27 research outputs found
Aquatic biosurvey of the Lovell River on UNH land
We assessed the physical, chemical and biological conditions at two sites along the Lovell River on University of New Hampshire (UNH) -owned conservation land. The discharge was 4.4 m3 s-1 at Site 1 and 5.7 m3 s -1 downstream at Site 2. Canopy coverage ranged from 8-25%. Canopy was dominated by Eastern Hemlock (79-84%). Much of the stream was strewn with large boulders and the substrate consisted of rocks of highly variable sizes ( 3-549 cm dia.). Specific conductivity (22.1-23.3 µS), pH (6.4) and temperature (7.9-8.3 °C) varied little between sites. Macro-invertebrate bio-indices indicated either excellent water quality with no apparent organic pollution (3.0/10) or good water quality with possible slight organic pollution (4.4/10)
Dynamics of nonequilibrium quasiparticles in a double superconducting tunnel junction detector
We study a class of superconductive radiation detectors in which the
absorption of energy occurs in a long superconductive strip while the redout
stage is provided by superconductive tunnel junctions positioned at the two
ends of the strip. Such a device is capable both of imaging and energy
resolution. In the established current scheme, well studied from the
theoretical and experimental point of view, a fundamental ingredient is
considered the presence of traps, or regions adjacent to the junctions made of
a superconducting material of lower gap. We reconsider the problem by
investigating the dynamics of the radiation induced excess quasiparticles in a
simpler device, i.e. one without traps. The nonequilibrium excess
quasiparticles can be seen to obey a diffusion equation whose coefficients are
discontinuous functions of the position. Based on the analytical solution to
this equation, we follow the dynamics of the quasiparticles in the device,
predict the signal formation of the detector and discuss the potentiality
offered by this configuration.Comment: 16 pages, 5 figures Submitted to Superconducting Science and
Technolog
Electrode effects on the conduction mechanisms in HfO2-based metal-insulator-metal capacitors
International audienc
Electrode oxygen-affinity influence on voltage non-linearities in high-k metal-insulator-metal capacitors
International audienc
Tantalum superconducting tunnel junctions for photon counting detectors
This paper presents the fabrication of Ta Superconducting Tunnel Junction detector working at 0.2 K to be used for photon counting instruments in astronomical applications. We would like to operate this type of detectors up to 2.5 Mm with a moderate energy resolution in order to offer innovative instrumental perspectives to the astronomical community. The Ta junction fabrication and characterization as well as photon counting experiments in the near-infrared are presented. Fabrication process improvements are discussed at the end of this paper
Optimizing MIM Device Electrical Properties: Impact of Bottom Electrodes and High k materials
International audienc
Combined spectroscopic ellipsometry and attenuated total reflection analyses of Al2O3/HfO2 nanolaminates
International audienc
High k for MIM and RRAM applications: Impact of the metallic electrode and oxygen vacancies
International audienc