8,106 research outputs found
A state-of-the-art review on torque distribution strategies aimed at enhancing energy efficiency for fully electric vehicles with independently actuated drivetrains
© 2019, Levrotto and Bella. All rights reserved. Electric vehicles are the future of private passenger transportation. However, there are still several technological barriers that hinder the large scale adoption of electric vehicles. In particular, their limited autonomy motivates studies on methods for improving the energy efficiency of electric vehicles so as to make them more attractive to the market. This paper provides a concise review on the current state-of-the-art of torque distribution strategies aimed at enhancing energy efficiency for fully electric vehicles with independently actuated drivetrains (FEVIADs). Starting from the operating principles, which include the "control allocation" problem, the peculiarities of each proposed solution are illustrated. All the existing techniques are categorized based on a selection of parameters deemed relevant to provide a comprehensive overview and understanding of the topic. Finally, future concerns and research perspectives for FEVIAD are discussed
Diboson search and multivariate tools in the ppÂŻâ lΜ + heavy flavor channel at CDF
This paper describes the application of machine learning techniques to the diboson search in the lepton plus neutrino plus heavy flavor jets channel at CDF. Three different aspects of this challenging search are analyzed: multijet background rejection with the use of a support vector machine discriminant, light/heavy flavor jets separation with a 26 input variable neural network and b-jet
specific energy corrections, where a resolution improvement is obtained feeding a neural network with both calorimeter and tracking information
Autonomic pain responses during sleep: a study of heart rate variability
The autonomic nervous system (ANS) reacts to nociceptive stimulation during sleep, but whether this reaction is contingent to cortical arousal, and whether one of the autonomic arms (sympathetic/parasympathetic) predominates over the other remains unknown. We assessed ANS reactivity to nociceptive stimulation during all sleep stages through heart rate variability, and correlated the results with the presence of cortical arousal measured in concomitant 32-channel EEG. Fourteen healthy volunteers underwent whole-night polysomnography during which nociceptive laser stimuli were applied over the hand. RR intervals (RR) and spectral analysis by wavelet transform were performed to assess parasympathetic (HF(WV)) and sympathetic (LF(WV) and LF(WV)/HF(WV) ratio) reactivity. During all sleep stages, RR significantly decreased in reaction to nociceptive stimulations, reaching a level similar to that of wakefulness, at the 3rd beat post-stimulus and returning to baseline after seven beats. This RR decrease was associated with an increase in sympathetic LF(WV) and LF(WV)/HF(WV) ratio without any parasympathetic HF(WV) change. Albeit RR decrease existed even in the absence of arousals, it was significantly higher when an arousal followed the noxious stimulus. These results suggest that the sympathetic-dependent cardiac activation induced by nociceptive stimuli is modulated by a sleep dependent phenomenon related to cortical activation and not by sleep itself, since it reaches a same intensity whatever the state of vigilance
Unexpected one-pot synthesis of highly conjugated pentacyclic diquinoid compounds
A new class of pentacyclic diquinoid compounds
has been synthesized with a facile one-pot reaction of
two molecules of 2-hydroxynaphthoquinone and 1-bromoalkanes
in the presence of ferrocene. These molecules were
isolated as enol tautomers that exhibit intramolecular hydrogen
bond and extended electronic conjugation as proved by the
intense absorption spectrum with a broad band between 400
and 600 nm. The spectroscopic and electrochemical characterization
of this new class of compounds has been performed.
One of the synthesized diquinoid derivatives showed a
significant cytotoxicity with IC50 values of 25−50 μM against
Cisplatin-Resistant SKOV3 and colon carcinoma SW480 cell
lines. The results of our study provide a valuable tool to a one-pot synthesis of highly conjugated polyquinones, analogous to
important biological systems, with significant antitumoral activity
Three-dimensional superimposition for patients with facial palsy: an innovative method for assessing the success of facial reanimation procedures
Facial palsy is a severe condition that may be ameliorated by facial reanimation, but there is no consensus about how to judge its success. In this study we aimed to test a new method for assessing facial movements based on 3-dimensional analysis of the facial surfaces. Eleven patients aged between 42 and 77 years who had recently been affected by facial palsy (onset between 6 and 18 months) were treated by an operation based on triple innervation: the masseteric to temporofacial nerve branch, 30% of the hypoglossal fibres to the cervicofacial nerve branch, and the contralateral facial nerve through two cross-face sural nerve grafts. Each patient had five stereophotogrammetric scans: at rest, smiling on the healthy side (facial stimulus), biting (masseteric stimulus), moving the tongue (hypoglossal stimulus), and corner-of-the-mouth smile (Mona Lisa). Each scan was superimposed onto the facial model of the "rest" position, and the point-to-point root mean square (RMS) value was automatically calculated on both the paralysed and the healthy side, together with an index of asymmetry. One-way and two-way ANOVA tests, respectively, were applied to verify the significance of possible differences in the RMS and asymmetry index according to the type of stimulus (p = 0.0329) and side (p < 0.0001). RMS differed significantly according to side between the facial stimulus and the masseteric one on the paralysed side (p = 0.0316). Facial stimulus evoked the most asymmetrical movement, whereas the masseteric produced the most symmetrical expression. The method can be used for assessing facial movements after facial reanimation
Measurement of Dielectric Suppression of Bremsstrahlung
In 1953, Ter-Mikaelian predicted that the bremsstrahlung of low energy
photons in a medium is suppressed because of interactions between the produced
photon and the electrons in the medium. This suppression occurs because the
emission takes place over on a long distance scale, allowing for destructive
interference between different instantaneous photon emission amplitudes. We
present here measurements of bremsstrahlung cross sections of 200 keV to 20 MeV
photons produced by 8 and 25 GeV electrons in carbon and gold targets. Our data
shows that dielectric suppression occurs at the predicted level, reducing the
cross section up to 75 percent in our data.Comment: 11 pages, format is postscript file, gzip-ed, uuencode-e
Arago (1810): the first experimental result against the ether
95 years before Special Relativity was born, Arago attempted to detect the
absolute motion of the Earth by measuring the deflection of starlight passing
through a prism fixed to the Earth. The null result of this experiment gave
rise to the Fresnel's hypothesis of an ether partly dragged by a moving
substance. In the context of Einstein's Relativity, the sole frame which is
privileged in Arago's experiment is the proper frame of the prism, and the null
result only says that Snell's law is valid in that frame. We revisit the
history of this premature first evidence against the ether theory and calculate
the Fresnel's dragging coefficient by applying the Huygens' construction in the
frame of the prism. We expose the dissimilar treatment received by the ray and
the wave front as an unavoidable consequence of the classical notions of space
and time.Comment: 16 pages. To appear in European Journal of Physic
Sublingual immunotherapy: administration, dosages, use
Allergen extracts for sublingual immunotherapy (SLIT) are currently marketed by several manufacturers, with administration schedules and amount of allergen(s) quite variable in the different products, although almost all are standardized biologically or immunologically. The allergen extracts for SLIT are available in two main pharmaceutical forms: solution to be delivered by drop-counters, pre-dosed actuators (mini-pumps) or disposable single-dose vials; tablets with appropriate composition that allows a slow (1-2 minutes) dissolution in the mouth in contact with saliva. In Europe, SLIT is prescribed in general for one or a few allergens, and mixtures are less used, though there is no immunological contraindication to give multiple allergens. SLIT traditionally involves a build-up phase and a maintenance phase with the top dose. The build-up phase has usually the duration of 4 - 6 weeks. The patient must start with the lowest concentration and gradually increase, using the different dosage preparations, until the maintenance dose is reached. Rush and ultra-rush inductions have been introduced, based on the safety profile of SLIT that is very favorable. For these reasons it has been suggested that an updosing phase maybe even not necessary. The no-updosing approach would result in a treatment that is more patient-friendly and convenient to manage. Indeed, the most recent randomized trials were performed with the no-updosing regimen and their results in term of safety were as favorable as the studies performed with the traditional updosing approach. The currently recommended duration of SLIT is comprised between 3 and 4 years depending on the clinical response in single patients
The three-dimensional wake behind an obstacle on a flat plate
Three dimensional incompressible wake behind blunt obstacle located at leading edge of flat plat
Signaling about norms: socialization under strategic uncertainty
We consider a signaling model where adults possess information about the dominant social norm. Children want to conform to whatever norm is dominant but, lacking accurate information, take the observed behavior of their parent as representative. We show that this causes a signaling distortion in adult behavior, even in the absence of conflicts of interest. Parents adopt attitudes that encourage their children to behave in a socially safe way, i.e. the way that would be optimal under maximum uncertainty about the prevailing social norm. We discuss applications to sexual attitudes, collective reputation, and trust
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