1,553 research outputs found
Carbon nanotube sensor for vibrating molecules
The transport properties of a CNT capacitively coupled to a molecule
vibrating along one of its librational modes are studied and its transport
properties analyzed in the presence of an STM tip. We evaluate the linear
charge and thermal conductances of the system and its thermopower. They are
dominated by position-dependent Franck-Condon factors, governed by a
position-dependent effective coupling constant peaked at the molecule position.
Both conductance and thermopower allow to extract some information on the
position of the molecule along the CNT. Crucially, however, thermopower sheds
also light on the vibrational levelspacing, allowing to obtain a more complete
characterization of the molecule even in the linear regime
Tool for efficient intermodulation analysis using conventional HB packages
A simple and efficient approach is proposed for the intermodulation analysis of nonlinear microwave circuits. The algorithm, which is based on a very mild assumption about the frequency response of the linear part of the circuit, allows for a reduction in computing time and memory requirement. Moreover. It can be easily implemented using any conventional tool for harmonic-balance circuit analysi
Possible Clinical Failure of Artemether-Lumefantrine in an Italian Traveler with Uncomplicated Falciparum Malaria.
Artemisinin-combination therapies (ACTs) are recommended for the treatment of uncomplicated malaria in endemic areas with multidrug resistant Plasmodium falciparum. We report a case of possible artemether-lumefantrine clinical failure in an Italian traveler with uncomplicated P. falciparum malaria imported from Democratic Republic of Congo
Inelastic and elastic collision rates for triplet states of ultracold strontium
We report measurement of the inelastic and elastic collision rates for
^{88}Sr atoms in the (5s5p)^3P_0 state in a crossed-beam optical dipole trap.
This is the first measurement of ultracold collision properties of a ^3P_0
level in an alkaline-earth atom or atom with similar electronic structure.
Since the (5s5p)^3P_0 state is the lowest level of the triplet manifold, large
loss rates indicate the importance of principle-quantum-number-changing
collisions at short range. We also provide an estimate of the collisional loss
rates for the (5s5p){^3P_2} state.Comment: 4 pages 5 figure
Influence of Winemaking Procedure and Grape Variety on the Colour and Composition of Young Red Wines
The influence of winemaking procedure and grape variety on the colour and composition of young redwines was evaluated. For this purpose, Tannat, Syrah and Merlot wines were elaborated in Uruguay in2011. Traditional maceration (TM), the addition of pectolytic enzymes (ENZ) and cold pre-fermentativemaceration before traditional maceration (CPM) were the alternative procedures of winemaking tested.Two batches of grapes (70 kg each) were employed for each winemaking procedure. Tannat wines hadthe highest colour intensity, red colour (a*), and anthocyanin, proanthocyanidin and alcohol content,and the lowest luminosity (L*) and pH values. CPM increased the colour intensity and total polyphenol,anthocyanin and proanthocyanidin content in Tannat and Merlot wines. Pectolytic additions enhancedcolour intensity and red colour and decreased the luminosity in all wines. Meanwhile, enzyme additionsenhanced proanthocyanidin content in all cases. Pectolytic enzyme significantly increased the methanollevels of the wines. Nevertheless, the amounts of this compound are far within maximum acceptable limits.Principal component analysis of the data shows significant separation between the wines of each variety,since the colour and composition are largely related to the cultivar and the vintage, despite the effect of thewinemaking procedures
An electrical probe for mechanical vibrations in suspended carbon nanotubes
The transport properties of a suspended carbon nanotube probed by means of a
STM tip are investigated. A microscopic theory of the coupling between
electrons and mechanical vibrations is developed. It predicts a
position-dependent coupling constant, sizeable only in the region where the
vibron is located. This fact has profound consequences on the transport
properties, which allow to extract information on the location and size of the
vibrating portions of the nanotube.Comment: 11 Pages, 12 color figures, accepted for publication on Physical
Review
On-wafer I/V measurement setup for the characterization of low-frequency dispersion in electron devices
Large-signal dynamic modelling of 111-V FETs
cannot he simply based on DC i/v characteristics, when
accurate performance prediction is needed. In fact,
dispersive phenomena due to self-heating and/or traps
(surface state densities and deep level traps) must be taken
into account since they cause important deviations in the
low-frequency dynamic drain current. Thus, static drain
current characteristics should he replaced with a suitable
model which also accounts for low-frequency dispersive
effects. The research community has proposed different
modelling approaches and quite often a characterisation by
means of pulsed i/v measurement systems has been suggested
as the more appropriate for the identification of lowfrequency
drain current models. In the paper, a new largesignal
measurement setup is presented which is based on
simple low-frequency sinusoidal excitations and it is easily
reproducible with conventional general-purpose lab
instrumentation. Moreover, the proposed setup is adopted in
the paper to extract a hackgating-like model for dispersive
phenomen
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