Abstract
E85 (85 vol% ethanol and 15 vol% gasoline blend) is one of the most promising sustainable fuels for SI engines, thanks to the optimum trade-off between pollutant emissions and cost of ...implementation, starting from a pure gasoline baseline.
From the point of view of engine performance, the most relevant differences from such a baseline are related to the heat of vaporization and to the laminar flame speed. The higher heat of vaporization helps to reduce combustion temperature, thus the risk of knocking, but it also slows down the air-mixing process; the small amount of Oxygen in the fuel molecule leads to a slightly different combustion behavior.
The goal of this study is to compare commercial gasoline (E5, 5 vol% ethanol and 95 vol% gasoline blend) and E85, by means of CFD 1D (GT-Power) and 3D (AVL-FIRE) simulations, using experimentally calibrated models. The reference engine is a single-cylinder, four-stroke, PFI motorcycle unit, with a displacement of 463 cc and a maximum power > 30 kW at 9500 rpm.
After the calibration, carried out on the E5 version, the fuel type is changed to E85 in the 1D model, in order to provide accurate Initial Conditions (ICs) and Boundary Conditions (BNDs) to the CFD-3D analysis. Then, a series of combustion simulations are carried out at maximum power operative point (9500 rpm – WOT), varying spark advance and equivalence ratios.
Results reveal that an increase of fuel flow rate and a new calibration of spark timing are needed when the engine runs on E85 to reach performances comparable to the ones obtained with E5. Simulations also show that, moving from E5 to E85, combustion efficiency can be significantly increased, with a small reduction in engine performance.
An estimation of specific emissions, provided by ECFM-3Z combustion model, show that, using E85, CO and HC emissions can be significantly reduced with a small increase of NO emissions, compared to gasoline case.
The Borexino collaboration has recently released the first simultaneous measurement of the interaction rates of pp, 7Be and pep solar neutrinos. This result was made possible by the unprecedented low ...background of the scintillator during Phase-II, together with new data analysis techniques. We present the data selection strategy of the Borexino solar neutrino analysis: we describe how we select the neutrino-like scintillation events according to event-based cuts which eliminate most of the external and cosmogenic backgrounds. We describe also how the spatial distribution of events and a β+/β− pulse shape discrimination variable are used in a multivariate fit approach to additionally constrain the residual cosmogenic 11C and external backgrounds.
•In laryngeal oncology it is crucial to assess mobility of vocal cord-arytenoid unit.•Current mobility assessment is flawed by weak inter-observer agreement.•Tumor extension assessment by dedicated ...radiologists is recommended.
In clinical practice the assessment of the “vocal cord-arytenoid unit” (VCAU) mobility is crucial in the staging, prognosis, and choice of treatment of laryngeal squamous cell carcinoma (LSCC). The aim of the present study was to measure repeatability and reliability of clinical assessment of VCAU mobility and radiologic analysis of posterior laryngeal extension.
In this multi-institutional retrospective study, patients with LSCC-induced impairment of VCAU mobility who received curative treatment were included; pre-treatment endoscopy and contrast-enhanced imaging were collected and evaluated by raters. According to their evaluations, concordance, number of assigned categories, and inter- and intra-rater agreement were calculated.
Twenty-two otorhinolaryngologists evaluated 366 videolaryngoscopies (total evaluations: 2170) and 6 radiologists evaluated 237 imaging studies (total evaluations: 477). The concordance of clinical rating was excellent in only 22.7% of cases. Overall, inter- and intra-rater agreement was weak. Supraglottic cancers and transoral endoscopy were associated with the lowest inter-observer reliability values. Radiologic inter-rater agreement was low and did not vary with imaging technique. Intra-rater reliability of radiologic evaluation was optimal.
The current methods to assess VCAU mobility and posterior extension of LSCC are flawed by weak inter-observer agreement and reliability. Radiologic evaluation was characterized by very high intra-rater agreement, but weak inter-observer reliability. The relevance of VCAU mobility assessment in laryngeal oncology should be re-weighted. Patients affected by LSCC requiring imaging should be referred to dedicated radiologists with experience in head and neck oncology.
A numerical study is presented where the impact of simultaneous thermal and mechanical loading on a railway wheel tread, as imposed by braking and rolling contact, is reported. A comparison is made ...of two-dimensional (2D) and 3D finite-element simulations of the thermomechanical problem featuring a material model that accounts for thermal expansion and plastic deformations. It is found that 2D simulations give unrealistic predictions of plastic deformations. The 3D simulations demonstrate a significant influence of the thermal loading also in cases of rather moderate temperature increases. In particular, the combination of thermal loading and high traction is found to be very detrimental.
The interaction of the surface plasmons of gold nanoparticles (NP) a few nanometers in size with fluorophores can be used to engineer their fluorescence properties. This possibility can be exploited ...in principle to obtain nanodevices for protein−protein recognition. We studied different types of constructs based on gold NPs on which derivatives of fluorescein were bound. The interaction of this fluorophore with the gold surface plasmon resonances, mainly occurring through quenching, affects its excited-state lifetime that is measured by fluorescence burst analysis in standard solutions. The binding of proteins to the gold NPs through antigen−antibody recognition further modifies the dye excited-state lifetime. This change can therefore be used to measure the protein concentration. The data reported here indicate that one can measure the concentration of bovine serum albumine in solution with an apparent limit of detection of 5 ± 2 pM.
About 99 per cent of solar energy is produced through sequences of nuclear reactions that convert hydrogen into helium, starting from the fusion of two protons (the pp chain). The neutrinos emitted ...by five of these reactions represent a unique probe of the Sun's internal working and, at the same time, offer an intense natural neutrino beam for fundamental physics. Here we report a complete study of the pp chain. We measure the neutrino-electron elastic-scattering rates for neutrinos produced by four reactions of the chain: the initial proton-proton fusion, the electron-capture decay of beryllium-7, the three-body proton-electron-proton (pep) fusion, here measured with the highest precision so far achieved, and the boron-8 beta decay, measured with the lowest energy threshold. We also set a limit on the neutrino flux produced by the
He-proton fusion (hep). These measurements provide a direct determination of the relative intensity of the two primary terminations of the pp chain (pp-I and pp-II) and an indication that the temperature profile in the Sun is more compatible with solar models that assume high surface metallicity. We also determine the survival probability of solar electron neutrinos at different energies, thus probing simultaneously and with high precision the neutrino flavour-conversion paradigm, both in vacuum and in matter-dominated regimes.
Inflammatory pseudotumour (IPT) is an uncommon disease with undefined pathogenesis. It is often characterized by local aggressiveness with compressive and displacing effects on surrounding ...structures. It may appear in different regions of the body, rarely involving perineural structures unilaterally. We present a case of a bilateral IPT around trigeminal branches in a patient with a long-term history of periorbital swelling and proptosis.
A search for the solar neutrino effective magnetic moment has been performed using data from 1291.5 days exposure during the second phase of the Borexino experiment. No significant deviations from ...the expected shape of the electron recoil spectrum from solar neutrinos have been found, and a new upper limit on the effective neutrino magnetic moment of μνeff<2.8×10−11 μB at 90% C.L. has been set using constraints on the sum of the solar neutrino fluxes implied by the radiochemical gallium experiments. Using the limit for the effective neutrino moment, new limits for the magnetic moments of the neutrino flavor states, and for the elements of the neutrino magnetic moments matrix for Dirac and Majorana neutrinos, are derived.
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