3,747 research outputs found
Battery choice and management for New Generation Electric Vehicles
Different types of electric vehicles (EVs) have been recently designed with the aim of solving pollution problems caused by the emission of gasoline-powered engines. Environmental problems promote the adoption of new-generation electric vehicles for urban transportation. As it is well known, one of the weakest points of electric vehicles is the battery system. Vehicle autonomy and, therefore, accurate detection of battery state of charge (SoC) together with battery expected life, i.e., battery state of health, are among the major drawbacks that prevent the introduction of electric vehicles in the consumer market. The electric scooter may provide the most feasible opportunity among EVs. They may be a replacement product for the primary-use vehicle, especially in Europe and Asia, provided that drive performance, safety, and cost issues are similar to actual engine scooters. The battery system choice is a crucial item, and thanks to an increasing emphasis on vehicle range and performance, the Li-ion battery could become a viable candidate. This paper deals with the design of a battery pack based on Li-ion technology for a prototype electric scooter with high performance and autonomy. The adopted battery system is composed of a suitable number of cells series connected, featuring a high voltage level. Therefore, cell equalization and monitoring need to be provided. Due to manufacturing asymmetries, charge and discharge cycles lead to cell unbalancing, reducing battery capacity and, depending on cell type, causing safety troubles or strongly limiting the storage capacity of the full pack. No solution is available on the market at a cheap price, because of the required voltage level and performance, therefore, a dedicated battery management system was designed, that also includes a battery SoC monitoring. The proposed solution features a high capability of energy storing in braking conditions, charge equalization, overvoltage and undervoltage protection and, obviously, SoC information in order to optimize autonomy instead of performance or vice-versa
Possible, alternative explanations of the T2K observation of the nu_e appearance from an initial nu_mu
An alternative explanation to the emergence of sin^2(2 theta_13) > 0 is
discussed. It is pointed out that the recorded T2K events might have been due
to some other new physics in the neutrino sector, related to the LSND/MiniBooNE
sterile neutrino anomalies, for which there is nowadays a growing evidence. The
presently running ICARUS detector with the CNGS beam will be able to
distinguish between these two possible sources of the effectComment: 5 pages, 1 figur
A new search for anomalous neutrino oscillations at the CERN-PS
The LSND experiment has observed a 3.8 sigma excess of anti-nu_e events from
an anti-nu_mu beam coming from pions at rest. If confirmed, the LSND anomaly
would imply new physics beyond the standard model, presumably in the form of
some additional sterile neutrinos. The MiniBooNE experiment at FNAL-Booster has
further searched for the LSND anomaly. Above 475 MeV, the nu_e result is
excluding the LSND anomaly to about 1.6 sigma but it introduces an unexplained,
new 3.0 sigma anomaly at lower energies, down to 200 MeV. The nu_e data have so
far an insufficient statistics to be conclusive with LSND's anti-nu_e. The
present proposal at the CERN-PS is based on two strictly identical LAr-TPC
detectors in the near and far positions, respectively at 127 and 850 m from the
neutrino (or antineutrino) target and focussing horn, observing the
electron-neutrino signal. This project will benefit from the already developed
technology of ICARUS T600, well tested on surface in Pavia, without the need of
any major R&D activity and without the added problems of an underground
experiment (CNGS-2). The superior quality of the Liquid Argon imaging TPC and
its unique electron - pi-zero discrimination allow full rejection of the NC
background, without efficiency loss for electron neutrino detection. In two
years of exposure, the far detector mass of 600 tons and a reasonable
utilization of the CERN-PS with the refurbished previous TT7 beam line will
allow to collect about 10^6 charged current events, largely adequate to settle
definitely the LSND anomaly.Comment: 23 pages, 17 figures, added watermark, better referencin
Design, synthesis and biological activity of selective hCAs inhibitors based on 2-(benzylsulfinyl)benzoic acid scaffold
A large library of derivatives based on the scaffold of 2-(benzylsulfinyl)benzoic acid were synthesised and tested as atypical inhibitors against four different isoforms of human carbonic anhydrase (hCA I, II, IX and XII, EC 4.2.1.1). The exploration of the chemical space around the main functional groups led to the discovery of selective hCA IX inhibitors in the micromolar/nanomolar range, thus establishing robust structure-activity relationships within this versatile scaffold. HPLC separation of some selected chiral compounds and biological evaluation of the corresponding enantiomers was performed along with molecular modelling studies on the most active derivatives
Operation of a LAr-TPC equipped with a multilayer LEM charge readout
A novel detector for the ionization signal in a single phase LAr-TPC, based
on the adoption of a multilayer Large Electron Multiplier (LEM) replacing the
traditional anodic wire arrays, has been experimented in the ICARINO test
facility at the INFN Laboratories in Legnaro. Cosmic muon tracks were detected
allowing the measurement of energy deposition and a first determination of the
signal to noise ratio. The analysis of the recorded events demonstrated the 3D
reconstruction capability of ionizing events in this device in liquid Argon,
collecting a fraction of about 90% of the ionization signal with signal to
noise ratio similar to that measured with more traditional wire chambersComment: 9 pages, 7 Figure
Hydraulic interactions between fractures and bedding planes in a carbonate aquifer studied by means of experimentally induced water-table fluctuations (Coaraze experimental site, southeastern France)
International audienceIn aquifers with variable permeability, the water exchanges between high and low permeability regions are controlled by the hydraulic head gradient. Past studies have addressed this problem mainly considering steadystate hydraulic conditions. To study such exchanges during water-table fluctuations, a spring was equipped with a water-gate that creates 10-meter artificial fluctuations of the water table. The water exchanges are discussed with respect to hydrochemical and pressure measurements in the groundwater. With successive water-table fluctuations the mineralization and pH decrease, but the bicarbonate content increases in response to carbon dioxide dissolution . At this scale of single fractures and surroundings, the hydrochemistry allows water flows from low or high permeability discontinuities to be discriminated. During hydraulic head fluctuations, the waters from low and high permeability discontinuities become mixed. During water-table rise, the low-permeability matrix contributed to the refilling of the permeable faults and to the mixing of the waters. Dynamic flows in the opposite direction to the hydraulic gradient can expel mineralized water, pushing it towards permeable discontinuities. This mechanism could be the cause of the peak in the mineralisation recorded in some karst springs at the start of flood events
Undiagnosed vertebral fractures influence quality of life in postmenopausal women with reduced ultrasound parameters.
Osteoporosis, a multifactorial systemic skeletal disease characterized by low bone mass and microarchitectural deterioration of bone tissue leading to increased bone fragility, is a worldwide public health problem. Vertebral fractures affect approximately 20% of postmenopausal women and are a hallmark of osteoporosis, but they may pass unnoticed, although they may lead to long-term immobility and disability.
The aims of the present study were (1) to determine the prevalence and the severity of vertebral fractures in a large cohort of Italian women aged 60 years or older with reduced values of quantitative ultrasound parameters; and (2) to assess whether vertebral fractures and other variables may be associated with health-related quality of life.
A total of 2450 women without back pain aged 60 years or older, after the completion of the Quality of Life Questionnaire of the European Foundation for Osteoporosis QUALEFFO, underwent quantitative ultrasound evaluation of the calcaneus; in those with a stiffness t-score of a parts per thousand currency sign -2 (n = 1194), radiographic evaluation of the thoracic and lumbar spine was carried out and then quantitative morphometry was performed by dedicated software (MorphoXpress). The radiographic analysis was carried out on 885 women who presented films of adequate quality. Multivariate regression was used to adjust for confounding variables.
Of those who underwent radiographic analysis, 681 had no vertebral fractures, and 204 women (23.1%) had one or more previously undiagnosed vertebral fractures. The prevalence of previously undiagnosed vertebral fractures increased with advancing age with more than 30% of women older than 75 years having at least one fracture. Older age, body mass index, and severe vertebral fractures were independently associated with a worse total QUALEFFO score.
We found that approximately one in four women showed evidence of undiagnosed vertebral fractures, and there was a strong age effect trend. Moreover, the severity grade of vertebral fractures, more than the number of fractures, was associated with a worsening of health-related quality of life as assessed by QUALEFFO. These findings confirm the clinical relevance of an early diagnosis of vertebral fractures and seem to support the usefulness of quantitative ultrasound measurements in the stratification of postmenopausal women at increased fracture risk
\u201cWoulda, coulda, shoulda\u201d. Workers\u2019 proactivity in the association between emotional demands and mental health
The present study aimed to explore the mediating role of hostile customer relations in the association between emotional dissonance and workers\u2019 mental health. Moreover, the moderating role of proactive personality as a buffer against hostile customer relations was assessed. Emotional demands become crucial within professions that involve a direct relationship with clients and, if poorly managed, can negatively affect workers\u2019 health and performance. Accordingly, data were collected on a sample of n = 918 mass-retail employees working for one of the leading Italian supermarket companies. Most participants were women (62.7%) with a mean age = 40.38 (SD = 7.68). The results of a moderated mediation analysis revealed that emotional dissonance was related to more hostile customer relations that, in turn, were associated with higher rates of mental health symptoms. Proactive personality emerged as a protecting factor that prevented the onset of conflicts with clients, particularly among workers experiencing high levels of emotional dissonance. The identification of resources enabling management of emotional demands could suggest suitable adaptive strategies for customer-facing roles, thus preventing the occurrence of adverse mental health symptoms
Free electron lifetime achievements in Liquid Argon Imaging TPC
A key feature for the success of the liquid Argon imaging TPC (LAr-TPC)
technology is the industrial purification against electro-negative impurities,
especially Oxygen and Nitrogen remnants, which have to be continuously kept at
an exceptionally low level by filtering and recirculating liquid Argon.
Improved purification techniques have been applied to a 120 liters LAr-TPC test
facility in the INFN-LNL laboratory. Through-going muon tracks have been used
to determine the free electron lifetime in liquid Argon against
electro-negative impurities. The short path length here observed (30 cm) is
compensated by the high accuracy in the observation of the specific ionization
of cosmic ray muons at sea level as a function of the drift distance. A free
electron lifetime of (21.4+7.3-4.3) ms, namely > 15.8 ms at 90 % C.L. has been
observed over several weeks under stable conditions, corresponding to a
residual Oxygen equivalent of about 15 ppt (part per trillion). At 500 V/cm,
the free electron speed is 1.5 m/ms. In a LAr-TPC a free electron lifetime in
excess of 15 ms corresponds for instance to an attenuation of less than 15 %
after a drift path of 5 m, opening the way to the operation of the LAr-TPC with
exceptionally long drift distances.Comment: 15 pages, 10 figures; Accepted for publication in JINS
Hydromechanical modeling of pulse tests that measure both fluid pressure and fracture-normal displacement of the Coaraze Laboratory site, France
21International audienceIn situ fracture mechanical deformation and fluid flow interactions are investigated through a series of hydraulic pulse injection tests, using specialized borehole equipment that can simultaneously measure fluid pressure and fracture displacements. The tests were conducted in two horizontal boreholes spaced one meter apart vertically and intersecting a near-vertical highly permeable fault located within a shallow fractured carbonate rock. The field data were evaluated by conducting a series of coupled hydromechanical numerical analyses, using both distinct-element and finite-element modeling techniques and both two- and three-dimensional model representations that can incorporate various complexities in fracture network geometry. One unique feature of these pulse injection experiments is that the entire test cycle, both the initial pressure increase and subsequent pressure fall-off, is carefully monitored and used for the evaluation of the in situ hydromechanical behavior. Field test data are evaluated by plotting fracture normal displacement as a function of fluid pressure, measured at the same borehole. The resulting normal displacement-versus-pressure curves show a characteristic loop, in which the paths for loading (pressure increase) and unloading (pressure decrease) are different. By matching this characteristic loop behavior, the fracture normal stiffness and an equivalent stiffness (Young's modulus) of the surrounding rock mass can be back-calculated. Evaluation of the field tests by coupled numerical hydromechanical modeling shows that initial fracture hydraulic aperture and normal stiffness vary by a factor of 2 to 3 for the two monitoring points within the same fracture plane. Moreover, the analyses show that hydraulic aperture and the normal stiffness of the pulse-tested fracture, the stiffness of surrounding rock matrix, and the properties and geometry of the surrounding fracture network significantly affect coupled hydromechanical responses during the pulse injection test. More specifically, the pressure-increase path of the normal displacement-versus-pressure curve is highly dependent on the hydromechanical parameters of the tested fracture and the stiffness of the matrix near the injection point, whereas the pressure-decrease path is highly influenced by mechanical processes within a larger portion of the surrounding fractured rock
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