Thermal effects on Common Rail injection system hydraulic performance

The effect of the fuel temperature on the hydraulic performance of a Common Rail diesel injector has been investigated with an integrated experimental-numerical approach. An experimental campaign pertaining to single and double injections has been performed for fuel tank temperatures ranging from 28C to 68C. In general, an augment in the injected mass has been observed for increasing values of the fuel tank temperature. Moreover, the interaction between the main and after injection changes with the temperature and the dwell time threshold for fusion-free injections increases with the fuel temperature. The temperature at the injector nozzle has been measured and compared with that obtained with a thermo-fluid dynamics simple model, showing that the real temperature and the estimated one correlate well. The influence of the fuel temperature on the internal injector dynamic has been explored by means of a validated 1D numerical model of the injector thermo-fluid dynamics. The main direct effect of the temperature variation concerns the needle lift, which reaches a larger peak value for a higher fuel temperature: this explains the general increment in the injected mass and the augmented value of the injection fusion threshold for the main-after injections. The obtained results could allow more accurate open-loop control strategies for the injected mass, which include thermal effects, to be implemente

The baryon number two system in the Chiral Soliton Model

We study the interaction between two B = 1 states in a Chiral Soliton Model where baryons are described as non-topological solitons. By using the hedgehog solution for the B = 1 states we construct three possible B = 2 configurations to analyze the role of the relative orientation of the hedgehog quills in the dynamics. The strong dependence of the intersoliton interaction on these relative orientations reveals that studies of dense hadronic matter using this model should take into account their implications.Comment: 4 pages, 2 figures, Proceedings for the Conference Few-Body Systems (APFB2011

Three-dimensional model of an external gear pump with an experimental evaluation of the flow ripple

A three-dimensional model of an external gear pump and a new application of an algorithm for the measurement of the unsteady flow rate in hydraulic pipes are presented. The experimental delivery flow ripple was compared with the outcomes of a simulation under different operating conditions. A comprehensive computational fluid dynamics model of the pump and of the high-pressure delivery circuit was developed in SimericsMP+. The pump model considers the clearances, which vary according to the shaft angle, between the tip of the tooth and the inner surface of the stator, as well as between the flanks of the teeth that are in contact. The pump delivery circuit is constituted by a straight pipe with a fixed orifice at the end to generate the load. The model of the entire system was preliminarily validated in terms of delivery pressure ripple. Subsequently, the simulated flow ripple was contrasted with the instantaneous flow rate, measured by means of an innovative flow meter. It was found that the proposed flow meter is reliable in assessing the flow oscillations under the various working conditions

Studying the Sivers function by model calculations

A formalism is presented to evaluate the Sivers function in constituent quark models. A non-relativistic reduction of the scheme is performed and applied to the Isgur-Karl model. The sign for the $u$ and $d$ flavor contributions that we obtained turns out to be opposite. The Burkardt Sum Rule is fulfilled to a large extent. After the estimate of the QCD evolution of the results from the momentum scale of the model to the experimental one, a reasonable agreement with the available data is obtained.Comment: To appear in the proceedings of Diffraction 2008: International Workshop On Diffraction In High Energy Physics, 9-14 Sep 2008, La Londe-les-Maures, France. Misprints corrected, reference adde

Experimental Investigation on Gasoline—Water Mixture Fuel Impingement Preparation Method and Spray Characteristics with High Injection Temperatures and Pressures

Gasoline–water mixed injections are of great interest because of their advantages for reduced manufacturing costs and improved atomization, with the potential to alleviate engine detonation and reduce emissions. In this work, based on the principle of impinging flow, a real-time gasoline–water mixture preparation system for internal combustion engines was designed and the preparation system performance was compared with the standard swirl mixing technique. An image processing method was established to quantify the uniformity of the prepared mixture. Based on the flash-boiling spray flash-boiling spray experiment, the spray characteristics of different gasoline–water mixtures were analyzed under different injection temperatures (30–160 °C) and pressures (5–15 MPa). The experiments showed that the impinging pressure was the main factor affecting the emulsification performance of the real-time gasoline–water mixture, and that the proposed real-time mixing system could produce a stable gasoline–water emulsion. For temperatures in the 30–160 °C range, the flash-boiling spray flash-boiling spray experiments showed that the spray penetration distance first decreases and then increases with the injection temperature, while the spray angle shows an opposite trend. The turning point corresponded to the flash-boiling point of each gasoline–water mixture

Experimental Measurement and Numerical Validation of the Flow Ripple in Internal Gear Pumps

The flow ripple in an internal gear pump was measured by means of a new instantaneous high-pressure flowmeter. The flowmeter consists of two pressure sensors mounted on a piece of the straight steel pump delivery line, and a variable-diameter orifice was installed along such a line, downstream of the flowmeter, to generate a variable load. Three distinct configurations of the high-pressure flowmeter, characterized by a different distance between the pressure transducers, were analyzed. Furthermore, a comprehensive fluid dynamic 3D model of the pump and of its high-pressure delivery line was developed and validated in terms of both the delivery pressure and the flow ripple for different pump working conditions. For the three examined configurations of the flowmeter, the measured flowrate time histories matched the corresponding numerical distributions at the various operating points. Finally, the validated 3D model was applied to predict the incomplete filling working of the interteeth chambers, and the obtained numerical pressure time histories along the delivery line were used, as input data, to assess the reliability of the flowmeter algorithm even in these severe operating conditions

Identifying New/Emerging Psychoactive Substances at the Time of COVID-19; A Web-Based Approach

© 2021 Catalani, Arillotta, Corkery, Guirguis, Vento and Schifano. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY).https://creativecommons.org/licenses/by/4.0/COVID-19-related disruptions of people and goods' circulation can affect drug markets, especially for new psychoactive substances (NPSs). Drug shortages could cause a change in available NPS, with the introduction of new, unknown, substances. The aims of the current research were to use a web crawler, NPSfinder®, to identify and categorize emerging NPS discussed on a range of drug enthusiasts/psychonauts' websites/fora at the time of the pandemic; social media for these identified NPS were screened as well. The NPSfinder® was used here to automatically scan 24/7 a list of psychonaut websites and NPS online resources. The NPSs identified in the time frame between January and August 2020 were searched in both the European Monitoring Center for Drugs and Drug Addictions (EMCDDA)/United Nations Office on Drugs and Crime (UNODC) databases and on social media (Facebook, Twitter, Instagram, Pinterest, and YouTube) as well, with a content qualitative analysis having been carried out on reddit.com. Of a total of 229 NPSs being discussed at the time of the pandemic, some 18 NPSs were identified for the first time by the NPSfinder®. These included six cathinones, six opioids, two synthetic cannabinoid receptor agonists (SCRAs), two phenylcyclohexylpiperidine (PCP)-like molecules, and two psychedelics. Of these NPSs, 10 were found to be previously unreported to either the UNODC or the EMCDDA. Of these 18 NPSs, opioids and cathinones were the most discussed on social media/reddit, with the highest number of threads associated. Current findings may support the use of both automated web crawlers and social listening approaches to identify emerging NPSs; the pandemic-related imposed restrictions may somehow influence the demand for specific NPS classes.Peer reviewe

Substance use in the club scene of Rome : a pilot study

Date of Acceptance: 28/08/2014 Copyright © 2014 Alessandro Emiliano Vento et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly citedOver the last few years, a wide number of unregulated substances have been marketed on the Web and in smart and head shops; they are usually advertised as legal alternatives to commonly known drugs and are defined as “smart drugs,” “legal highs,” and “novel psychoactive substances” (NPS). Aim of our work is to describe use habits and distribution of NPS in a population of young adults in Rome club scene. Methods. A self-administered questionnaire was proposed to subjects over 18 years of age at the entrance of 5 nightclubs in Rome. Socioeconomic characteristics and substance use were investigated. Results. Preliminary results give evidence that 78% of respondents have a lifetime history of NPS use. In addition, 56% of the sample has consumed illicit drugs in the past and 39% has used psychoactive substances in the 12 hours preceding the questionnaire administration. Conclusions. A significant proportion of subjects report use of novel psychoactive substances; traditional illicit drugs consumption, particularly cocaine, appears to be very high as well in the club scene. These data highlight a serious public health challenge, since pharmacological, toxicological, and psychopathological effects linked to interactions among all these substances may be unpredictable and sometimes fatal in vulnerable individualsPeer reviewedFinal Published versio

The psychonauts' world of cognitive enhancers

© 2020 Napoletano, Schifano, Corkery, Guirguis, Arillotta, Zangani and Vento. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY - https://creativecommons.org/licenses/by/4.0/). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.Background: There is growing availability of novel psychoactive substances (NPS), including cognitive enhancers (CEs) which can be used in the treatment of certain mental health disorders. Whilst treating cognitive deficit symptoms in neuropsychiatric or neurodegenerative disorders using CEs might have significant benefits for patients, the increasing recreational use of thesesubstances by healthy individuals raises many clinical, medico-legal and ethical issues. Moreover, it has become very challenging for clinicians to keep up-to-date with CEs currently available as comprehen-sive official lists do not exist.Methods: Using a web crawler (NPSfinder®), the present study aimed at assessing psychonaut fora/ platforms to better understand the online situation regarding CEs. We compared NPSfinder® entries with those from the European Monitoring Centre for Drugs and Drug Addiction (EMCDDA), and from the United Nations Office on Drugs and Crime (UNODC) NPS databases, up to spring 2019. Any substance that was iden-tified by NPSfinder® was considered a CE if it was either described as having nootropic abilities by psychonauts or if it was listed among the known CEs by Froestl and colleagues.Results: A total of 142 unique CEs were identified by NPSfinder®. They were divided into 10 categories, including plants/ herbs/products (29%), prescribed drugs (17%), image and performance enhancing drugs (IPEDs) (15%), psychostimulants (15%), miscellaneous (8%), Phenethylamines (6%), GABAergic drugs (5%), cannabimimetic (4%), tryptamines derivatives (0.5%) and piperazine derivatives (0.5%). A total of 105 chemically different substances were uniquely identified by NPSfinder®. Only one CE was uniquely identified by the EMCDDA; no CE was uniquely identified by the UNODC.Conclusions: These results show that NPSfinder® is helpful as part of an Early Warning System, which could update clinicians with the growing numbers and types of nootropics in the increasingly difficult-to-follow internet world. Improving clinicians’ knowledge of NPS could promote more effective prevention and harm reduction measures in clinical settings.Peer reviewe