2,571 research outputs found
Measuring the Temperature of a Mesoscopic Quantum Electron System by means of Single Electron Statistics
We measure the temperature of a mesoscopic system consisting of an
ultra-dilute two dimensional electron gas at the interface in a
metal-oxide-semiconductor field effect transistor (MOSFET) quantum dot by means
of the capture and emission of an electron in a point defect close to the
interface. Contrarily to previous reports, we show that the capture and
emission by point defects in Si n-MOSFETs can be temperature dependent down to
800 mK. As the finite quantum grand canonical ensemble model applies, the time
domain charge fluctuation in the defect is used to determine the temperature of
the few electron gas in the channel.Comment: 4 Figures (color
The dynamical nature of time
It is usually assumed that the "" parameter in the equations of dynamics
can be identified with the indication of the pointer of a clock. Things are not
so easy, however. In fact, since the equations of motion can be written in
terms of but also of , being any well behaved function, each
one of those infinite parametric times is as good as the Newtonian one to
study classical dynamics. Here we show that the relation between the
mathematical parametric time in the equations of dynamics and the physical
dynamical time that is measured with clocks is more complex and subtle
than usually assumed. These two times, therefore, must be carefully
distinguished since their difference may have significant consequences.
Furthermore, we show that not all the dynamical clock-times are necessarily
equivalent and that the observational fingerprint of this non-equivalence has
the same form as that of the Pioneer anomaly.Comment: 13 pages, no figure
An efficient and versatile synthesis of new Trojan-horse cephalosporins
A useful synthesis of new dual-action cephalosporins is reported. These molecules could represent a fascinating tool for treatment of bacterial infectious diseases, since they display a possible inhibitor activity towards beta-lactamase-expressing bacteria. The major advantage of this 3-step synthetic approach lies in its versatility, which allows the systematic preparation of a wide pool of new molecules
Observation of electro-activated localized structures in broad area VCSELs
We demonstrate experimentally the electro-activation of a localized optical
structure in a coherently driven broad-area vertical-cavity surface-emitting
laser (VCSEL) operated below threshold. Control is achieved by
electro-optically steering a writing beam through a pre-programmable switch
based on a photorefractive funnel waveguide.Comment: 5 Figure
Acute Treatment with Renal Denervation in a Patient with Resistant Hypertension and Hemorrhagic Stroke
A 49-year-old man with refractory hypertension was admitted
to our hospital in a coma caused by hemorrhagic stroke. Severe
hypertension was observed during hospitalization despite a full
antihypertensive therapy. Considering the risk of enlargement of
the intracranial hematoma, the decision was made to perform renal
denervation (RDN). A significant blood pressure reduction was
obtained after RDN. The patient had a progressive improvement of
general conditions and came out of the coma after a few days. This
case underlines the safety and the feasibility of RDN in a critically
ill patient
An approach based on VR to design industrial human-robot collaborative workstations
This paper presents an integrated approach for the design of human-robot collaborative workstations in industrial shop floors. In particular, the paper presents how to use virtual reality (VR) technologies to support designers in the creation of interactive workstation prototypes and in early validation of design outcomes. VR allows designers to consider and evaluate in advance the overall user experience, adopting a user-centered perspective. The proposed approach relies on two levels: the first allows designers to have an automatic generation and organization of the workstation physical layout in VR, starting from a conceptual description of its functionalities and required tools; the second aims at supporting designers during the design of human-machine interfaces (HMIs) by interaction mapping, HMI prototyping and testing in VR. The proposed approach has been applied on two realistic industrial case studies related to the design of an intensive warehouse and a collaborative assembly workstation for automotive industry, respectively. The two case studies demonstrate how the approach is suited for early prototyping of complex environments and human-machine interactions by taking into account the user experience from the early phases of design
Gender differences in cyclists\u2019 crashes: an analysis of routinely recorded crash data
Previous research on gender differences in road crashes has focussed uniquely on car drivers and there has been little research examining such differences among cyclists. In this study, we investigated gender differences in bicycle crashes, using routinely recorded crash data. The present paper focussed on characteristics related to the type of crashes (type of collision and opponent vehicle), the infrastructure (road type and type of road segment), the environmental (season, road surface condition and weather) and time period (time of the day and day of the week). Results revealed that, compared to women cyclists, men cyclists were more likely to be involved in a crash regardless the cyclists\u2019 age. Moreover, we found gender differences in terms of type of road segment, type of opponent vehicle, type of manoeuvre of the opponent vehicle and of the cyclists, type of collision, time of the day, day of the week and season
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