performances of an orc power unit for waste heat recovery on heavy duty engine

Abstract Reciprocating internal combustion engines (ICE) are still the most used in the sector of the on-the-road transportation, both for passengers and freight. CO2 reduction is the actual technological driver, considering the worldwide greenhouse reduction targets committed by most governments. In ICE more than one third of the fuel energy used is rejected to the environment as thermal waste through the exhaust gases. Therefore, a greater fuel economy could be achieved, if this energy was recovered and converted into useful mechanical or electrical power. This recovery appears very interesting, in particular for those engines that run at almost steady working conditions, like marine, agricultural, industrial or long-hauling vehicle applications. In this paper, an ORC-based power unit was tested on a heavy duty diesel engine. Energetic and exergetic analyses have been carried out in order to assess the real performances of the ORC unit and to individuate differences with the theoretical ones. A single stage impulse axial turbine has been tested in this work, complete with an electric variable speed generator and an AC/DC converter. The tests demonstrated that the energy conversion chain is not negligible at all and an overall net efficiency of the power unit was around 2-3 % with respect to a 10% of thermodynamic efficiency

Correlation between Migraine Severity and Cholesterol Levels.

INTRODUCTION: Several studies have documented increased cardiovascular risk factors, particularly hypercholesterolemia, in the migraine population with respect to controls. However, no studies have investigated the possible relationship between headache severity parameters and lipid serum levels. METHODS: This study evaluated the lipid asset in 52 migraine patients (17 with and 36 without aura) before and after treatment with drugs for migraine prophylaxis for 3 months. RESULTS: High frequency (HF, ≥ 8/month) and intensity (HI, ≥ 5 Numeric Rating Score) vs. low frequency (LF, < 8/month) and intensity (LI, < 5) of crises were associated with significantly higher cholesterol levels, both total (TC, HF vs. LF, P < 0.0001; HI vs. LI, P < 0.0001) and LDL (LDL-c, HF vs. LF, P < 0.0001, and HI vs. LI, P < 0.0001). In treated patients, a significant decrease in number and intensity of crises was associated with a significant reduction of TC and LDL-c (P < 0.001). A direct linear correlation was also found between frequency and intensity of crises and lipid levels (TC/frequency, P < 0.0001; TC/intensity, P < 0.0001; LDL-c/frequency, P < 0.0001; LDL-c/intensity, P < 0.0001). No significant difference was found in the evaluated parameters for the subgroups of patients with and without aura. DISCUSSION: This study shows a significant positive association between migraine frequency and intensity with total and LDL cholesterol, demonstrating for the first time a significant reduction of these lipid parameters after migraine prophylaxis. However, in view of the retrospective design of the study and the small population size, these results should be considered as preliminary, to be confirmed by future prospective controlled trials

Uprighting impacted mandibular second molar using a skeletal anchorage: a case report

The aim of this case report is to present an innovative combined orthodontic-surgical technique to disimpact mandibular second molar (MM2) using an orthodontic miniscrew and an elastic chain. The impact on the Oral health-related quality of life (OHRQoL) was also evaluated. Using the present techinique, it is possible to expose the impacted tooth, insert a self-drilling miniscrew in the retromolar area, and remove the bud of third mandibular molar. At the same time the orthodontic force is applied with the use of an elastomeric chain that connects the head of miniscrew and vestibular and oral buttons bonded on MM2. A close traction is performed for the whole treatment time without the reactivation of the elastic force. The use of skeletal anchorage allowed the disimpaction of impacted MM2 in a short treatment time (about three months) avoiding the typical biomechanical side effects of traditional orthodontic appliance and increasing the effectiveness of the treatment. Further studies are necessary to evaluate the real advantages and disadvantages of this combined orthodontic-surgical approach

Insomnia symptoms predict emotional dysregulation, impulsivity and suicidality in depressive bipolar II patients with mixed features

Introduction: Insomnia symptoms are very common in Bipolar Disorder. Our aim was to assess the potential association between insomnia, emotion dysregulation and suicidality in subjects with Bipolar Disorder. Methods: Seventy-seven subjects with Bipolar Disorder type II with a depressive episode with mixed features were recruited. Patients were assessed with SCID-DSM-5, the Insomnia Severity Index (ISI), the Difficulties in Emotion Regulation Scale (DERS), the Scale for Suicide Ideation (SSI) while evaluating manic and depressive symptoms. Results: Subjects with insomnia symptoms compared to those without showed higher scores in the DERS scale and subscales, including impulsivity, and in the SSI scale. Insomnia symptoms significantly predicted the severity of depressive symptoms, emotion dysregulation, and suicidality in subjects with bipolar disorder. In particular, insomnia was related to difficulties in some areas of emotion regulation including impulsivity. Emotion dysregulation significantly mediated the association between insomnia and depressive symptoms (Z = 2.9, p = 0.004). Furthermore, emotional impulsivity mediated the association between insomnia symptoms and suicidality (Z = 2.2, p = 0.03). Conclusion: In our study, subjects with bipolar disorder suffering from insomnia experienced a greater severity of depressive symptoms and suicidality compared to subjects without insomnia. Insomnia was associated with emotion dysregulation, impulsivity and suicidality. Further research is necessary to investigate if these latter features may benefit from early insomnia treatment in subjects with bipolar disorder

Albumin supplementation dampens hypercoagulability in COVID-19. A preliminary report

Coronavirus disease 2019 (COVID-19) is characterized by severe acute respiratory syndrome coronavirus 2 (SARSCoV-2) needing mechanical ventilation and intensive care unit (ICU) treatment. In addition to lung disease, clinical features of SARS-CoV-2 include myocardial damage and ischemia-related vascular disease, which are associated with a hypercoagulable state (e.g., high D-dimer levels) predisposing to thrombotic-related complications and eventually death.1–3 Serum albumin levels &lt;3.5 g/dL are detectable in SARS-CoV-2 patients and associated with death4 and elevated D-dimer and thrombotic events,5 which is in accordance with previous studies reporting an association between serum albumin &lt;3.5 g/dL and risk of venous and arterial thrombosis.6 Thus, we tested the hypothesis that albumin supplementation could dampen hypercoagulability in SARS-CoV-2 with serum albumin &lt;3.5 g/dL. This is an observational cohort study performed at a large university hospital located in Rome and Chieti (Italy) and devoted to COVID-19 care

Emergency Department as an epidemiological observatory of Human Mobility: the experience of the Moroccan population

We conducted a retrospective study of the accesses to the Emergency Department registered from January 2000 to December 2014 in 5 major hospitals in the Metropolitan Area of Rome. We extrapolated data relating to patients of Moroccan origin from about 5 million total accesses, so we compared with Italians data which, in the same period, came to ED. The Moroccan population is distinguished by a larger number of diagnoses belonging to the ICD-9 code of Infectious Diseases and, more precisely, to Respiratory Infectious Diseases. There are also no differences in the assignment of such diagnoses to Moroccans with Italian citizenship, and this led to think that this could play an important role in the use of the ED and moreover that enrollment to the National Health Service may reduce its inappropriate use. Regarding to Degenerative Disorders, the result of our analysis is quite emblematic, showing that the accesses to the ED is due to Cardiovascular Diseases: 6.33% of Italians' accesses against 1.81% of Moroccans and 2.36% of Moroccans with Italian citizenship. The main explanation for this difference is, obviously, due to the age of the population: about 60% of Moroccans who accessed to ED was less than 40 years old. It is interesting how, in the field of ​​Cardiovascular Diseases, Moroccans have a lower percentage of diagnosis compared to Italians for acute diseases and a greater percentage of diagnoses for chronic diseases, suggesting once again that accesses to ED for migrants often is due to the inability to use the general services of the National Health Service. In conclusion, from the point of view of the Emergency Department, Migration Medicine still has Infectious Diseases as the main reason for access. Degenerative Disorders remain a prerogative of the Italians, but we could certainly assume that the Moroccan population would develop at some point with the aging

Design and analysis of a sliding vane pump for waste heat to power conversion systems using organic fluids

The current research work assesses the relevance of pumping work in energy recovery systems based on bottoming Organic Rankine Cycles (ORC) and presents the development of a sliding vane pump prototype for small scale units. The novel device was installed on an ORC-based power unit for waste heat to power conversion in compressed air applications in which the heat source was a compressor lubricant while the heat sink was tap water. Tests were performed with R236fa as working fluid at different pressure rises (3.9-9.7) and revolution speeds (500-1300 RPM). The experimental dataset was used to validate a numerical one-dimensional CFD model of the sliding vane pump developed in the GT-SUITE™ environment. The model takes into account the fluid dynamics and friction phenomena that are involved in the pump operation such as vane filling and emptying, leakages as well as dry and viscous friction between components in relative motion. The modelling platform was further exploited to retrieve performance maps of the pump, angular vane pressure evolution as well as to break down leakage and friction losses. The effects of geometrical features on the pump performance were eventually investigated through variations of the aspect ratio. With reference to the best experimental operating point (pressure rise 9.7, revolution speed 1250 RPM), simulations showed that, with a stator 5% bigger than the nominal one and the length almost halved, overall pump efficiency could be increased from the experimental 36.9% to a value of 48.0%. © 2017 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (https:// creativecommons.org/licenses/by/4.0/)

Fuel economy benefits of a new engine cooling pump based on sliding vane technology with variable eccentricity

During a homologation cycle, engine cooling pump operates at off-design conditions that are characterized by low efficiency and, in turn, impacts on the vehicle fuel economy and emissions performances. Furthermore, the conventional centrifugal technology struggles with the need of implementing thermal management strategies. In order to address these issues, the current paper presents the development of an innovative engine cooling pump for automotive applications that is based on the sliding vane technology. The experimental performances of the novel pump were compared with the ones of a conventional centrifugal device through a test bench that reproduced the real operating conditions of a passenger car engine cooling circuit. Characteristic curves and efficiency maps were further used as input data for a comprehensive model that takes into account heat transfer and hydraulic phenomena of a real engine cooling circuit. The simulation platform was eventually used to assess the energy benefits of the sliding vane pump over a centrifugal machine along theWorldwide harmonized Light vehicles Test Cycle (WLTC) with respect to a fixed geometrical configuration and an optimized one achieved through a control on the eccentricity between stator and rotor that tuned up the flow rate on the cooling demand. A mechanical power reduction of 12% was estimated for a sliding vane pump mechanically linked to the engine crankshaft while the benefits reached 22% if the eccentricity actuation was considered. In terms of CO2 reduction, the benefits related to the introduction of the sliding vane pump are of about 0.5 g/km.Dr. Giulio Contaldi, CEO of Ing. Enea Mattei S.p.A. and Marco Benincasa, technical sales director of Meccanotecnica Umbra S.p.A., are gratefully acknowledged for the continuous research funding and technical support

Probing the N = 32 shell closure below the magic proton number Z = 20: Mass measurements of the exotic isotopes 52,53K

The recently confirmed neutron-shell closure at N = 32 has been investigated for the first time below the magic proton number Z = 20 with mass measurements of the exotic isotopes 52,53K, the latter being the shortest-lived nuclide investigated at the online mass spectrometer ISOLTRAP. The resulting two-neutron separation energies reveal a 3 MeV shell gap at N = 32, slightly lower than for 52Ca, highlighting the doubly-magic nature of this nuclide. Skyrme-Hartree-Fock-Boguliubov and ab initio Gorkov-Green function calculations are challenged by the new measurements but reproduce qualitatively the observed shell effect.Comment: 5 pages, 5 figure