117 research outputs found

    Extension of Low Temperature Emission Test to Euro 6 Diesel Vehicles

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    The European Commission Regulations No 692/2008 and No 715/2007 set the regulatory framework for type-approval of motor vehicles with respect to emissions from light passenger and commercial vehicles (Euro 5/6). One of the applicable tests is the low temperature emission test (Type VI), which is conducted at sub-ambient temperature conditions (-7°C). The low temperature emission test is currently required only for vehicles with positive ignition engines. However the Type VI test to diesel vehicles is under consideration, mainly because of the introduction of the new technologies in diesel engines in order to comply with the Euro5/6 emission standards, of which the efficiency in controlling emission may strongly depend on the ambient temperature. This is especially true for Exhaust Gas Recirculation (EGR) systems and after-treatment systems for Oxides of Nitrogen (NOx) that are deactivated or not operate in cold weather conditions, may result in elevated NOx emissions. The review should consider whether to extend the low temperature emission test to Euro 6 diesel vehicles and whether emission limit should be introduced in the future. This report provides a picture of the low temperature emission performances of late technology diesel vehicles The main results of the experimental activity carried out at JRC to investigate the behaviour at low temperature of Euro 5/6 diesel passenger cars are summarised and discussed.JRC.F.8-Sustainable Transpor

    Review of the European Test Procedure for Evaporative Emissions: Main Issues and Proposed Solutions

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    The current European legislation on evaporative emissions dates back to the Directive 98/69/EC (Euro 3-4 standards). Since then neither the emission limits nor the test procedure have changed. As stated in several legislative documents the European Commission has now the obligation to review the evaporative emissions test procedure in order to improve control of evaporative emissions. In this report the main issues related to real world evaporative emissions and to the impact of ethanol used as transport fuel on the same emissions are addressed. In addition, modifications to the current European legislation to improve the control of real world evaporative emissions and to minimize the impact of ethanol are proposed. Moreover, this report provides an overview on evaporative emissions from passenger cars and on the effect of ethanol on them. A comparison between the European and US legislation is also provided.JRC.F.8-Sustainable Transpor

    Physical Characterization of Exhaust Particle Emissions from Late Technology Gasoline Vehicles

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    The study assesses the feasibility of introducing the regulated particle number measurement procedure for the regulation of gasoline vehicles, focusing on the established cut-off size of 23 nm. A range of late technology gasoline vehicles were tested under regulated and unregulated test conditions. The results indicated a distinct emission behavior of Direct Injection Gasolines (G-DI), Port Fuel Injection gasolines (PFI) and Diesels equipped with Particulate Filters (DPF), that differed both in terms of the absolute levels but also with respect to the fraction of undetected nano-sized non-volatile particles. The latter was found to be around 20% (based on comparisons with a Condensation Particle Counter (CPC) having a 50% cut-off size at 4.5 nm) for three G-DI vehicles tested, but ranged between 40 and 70% for the two PFIs measured. Interestingly, a relatively large fraction of undetected nanosized was also observed for two late technology DPFs, ranging between 30 and 50%. To a large extent these differences originate from differences in the size distributions and the relatively blunt shape of the counting efficiency curve of PMP compliant CPCs. Under conditions favouring nucleation mode formation in the dilution tunnel, excessive particle concentrations were detected by the low cut-off size CPCs, and especially the one with a d50 at 4.5 nm, that could exceed those of the PMP compliant CPC by up to one order of magnitude. However, the concentration of these nano-sized particles was found to decrease with increasing the dilution ratio in the first stage of the Volatile Particle Remover (VPR), indicating that this is rather a volatile artifact possibly originating from re-nucleation of evaporated material downstream of the VPR. The study also investigated the potential offered by a range of available approaches to effectively control particle emissions from G-DIs. These included the use of a Gasoline Particulate Filter (GPF), the introduction of ethanol in the fuel but also an advanced engine concept combining port and direct fuel injection. The GPF system was found to very efficient in controlling particle number emissions under all driving conditions, having no visible impact on carbon dioxide emissions. The use of fuel with hi-ethanol content (75-85%) was also found to be beneficial especially at high engine loads (up to 97% reduction of non-volatile particle numbers ) and during cold start operation (up to 70% reduction). The tests with the “hybrid” G-DI-PFI vehicle indicated that there exists the potential for significant reduction of PM formation through engine measures. The non-volatile particle number emissions of this vehicle remained below the diesel limit over all hot start tests.JRC.F.8-Sustainable Transpor

    Particle Emissions from a Euro 5a Certified Diesel Passenger Car

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    The particle emissions of a Euro 5 technology DPF-equipped diesel passenger car were characterized under regulated and unregulated conditions. More specifically, the vehicle was tested under the New European Driving Cycle but also under the Common Artemis Driving Cycles. Measurements were conducted at 22°C and -7°C test cell temperatures. The particle characteristics investigated included PM mass emissions as well as “non-volatile” particle number emissions. The PMP compliant particle number measurement system was supplemented with two additional CPCs allowing for the quantification of unregulated sub-23 nm particles in the size bins of 4.5 to 10 nm and 10 nm to 23 nm. The DPF regenerated actively thrice during the measurement campaign providing some information on the emission performance of the vehicle under these conditions.JRC.DDG.F.9-Sustainable Transport (Ispra

    Consumption patterns of energy drinks in university students. A systematic review and meta-analysis

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    Energy Drinks (EDs) use is promoted to stimulate mental and/or physical activity, and over the years their popularity increased, especially among young people. However, the use of EDs is often improper and can induce some adverse effects for human health. The purpose of this systematic review and metaanalysis was to analyse the literature to characterize prevalence of ED consumption and motivations to use among undergraduate students. Furthermore, adverse effects and health-related behaviors associated to ED use were explored. This systematic review was carried out according to the PRISMA Statement and the databases PubMed, Scopus and Web of Science were used for data research. 71 articles published between 2007 and 2021 met the inclusion criteria and were included in the review. The estimated overall prevalence of ED consumption was 42.9% in undergraduate students (95% CI:42.5%-43.3%), with significant heterogeneity among studies (Q test: p<0.001; I2 =99.4%) . The main reasons for their use were engagement in study, projects or examinations, to stay awake or alert, physical activity/sport engagement. Sleep disturbance and increased heart rate or blood pressure were the most commonly reported adverse effects. ED consumption was frequently associated with alcohol use and smoking. These findings suggest that inappropriate use of EDs and related unhealthy behaviors should be early identified and addressed through effective educational interventions

    Echocardiographic nomograms for chamber diameters and areas in Caucasian children

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    BACKGROUND: Although a quantitative evaluation of cardiac chamber dimensions in pediatric echocardiography is often important, nomograms for these structures are limited. The aim of this study was to establish reliable echocardiographic nomograms of cardiac chamber diameters and areas in a wide population of children. METHODS: A total of 1,091 Caucasian Italian healthy children (age range, 0 days to 17 years; 44.8% female) with body surface areas (BSAs) ranging from 0.12 to 1.8 m(2) were prospectively enrolled. Twenty-two two-dimensional and M-mode measurements of atrial and ventricular chamber diameters and areas were performed. Models using linear, logarithmic, exponential, and square-root relationships were tested. Heteroscedasticity was tested by the White test and the Breusch-Pagan test. Age, weight, height, and BSA, calculated by the Haycock formula, were used as the independent variables in different analyses to predict the mean value of each echocardiographic measurement. The influence of various confounders, including gender, type of delivery, prematurity, and interobserver variability, was also evaluated. Structured Z scores were then computed. RESULTS: The Haycock formula provided the best fit and was used when presenting data as predicted values (mean ? 2 SDs) for a given BSA and within equations relating echocardiographic measurements to BSA. Confounders were not included in the final models, because they did not show significant effects for most of the measurements. CONCLUSIONS: Echocardiographic reference values are presented for chamber area and diameters, derived from a large population of healthy children. These data partly cover a gap in actual pediatric echocardiographic nomograms. Further studies are required to reinforce these data, as well as to evaluate other parameters and ethnicities

    Prognostic role of BNP in children undergoing surgery for congenital heart disease: analysis of prediction models incorporating standard risk factors.

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    BACKGROUND: The routine use of brain natriuretic peptide (BNP) in pediatric cardiac surgery remains controversial. Our aim was to test whether BNP adds information to predict risk in pediatric cardiac surgery. METHODS: In all, 587 children undergoing cardiac surgery (median age 6.3 months; 1.2-35.9 months) were prospectively enrolled at a single institution. BNP was measured pre-operatively, on every post-operative day in the intensive care unit, and before discharge. The primary outcome was major complications and length ventilator stay \u3e15 days. A first risk prediction model was fitted using Cox proportional hazards model with age, body surface area and Aristotle score as continuous predictors. A second model was built adding cardiopulmonary bypass time and arterial lactate at the end of operation to the first model. Then, peak post-operative log-BNP was added to both models. Analysis to test discrimination, calibration, and reclassification were performed. RESULTS: BNP increased after surgery (p CONCLUSIONS: Our data indicates that BNP may improve the risk prediction in pediatric cardiac surgery, supporting its routine use in this setting

    Testing the 2018 NIA-AA research framework in a retrospective large cohort of patients with cognitive impairment: From biological biomarkers to clinical syndromes

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    Background According to the 2018 NIA-AA research framework, Alzheimer's disease (AD) is not defined by the clinical consequences of the disease, but by its underlying pathology, measured by biomarkers. Evidence of both amyloid-beta (A beta) and phosphorylated tau protein (p-tau) deposition-assessed interchangeably with amyloid-positron emission tomography (PET) and/or cerebrospinal fluid (CSF) analysis-is needed to diagnose AD in a living person. Our aim was to test the new NIA-AA research framework in a large cohort of cognitively impaired patients to evaluate correspondence between the clinical syndromes and the underlying pathologic process testified by biomarkers. Methods We retrospectively analysed 628 subjects referred to our centre in suspicion of dementia, who underwent CSF analysis, together with neuropsychological assessment and neuroimaging, and were diagnosed with different neurodegenerative dementias according to current criteria, or as cognitively unimpaired. Subjects were classified considering CSF biomarkers, and the prevalence of normal, AD-continuum and non-AD profiles in each clinical syndrome was calculated. The positivity threshold of each CSF biomarker was first assessed by receiver operating characteristic analysis, using A beta-positive/negative status as determined by amyloid-PET visual reads. The agreement between CSF and amyloid-PET data was also evaluated. Results Among patients with a clinical diagnosis of AD, 94.1% were in the AD-continuum, whereas 5.5% were classified as non-AD and 0.4% were normal. The AD-continuum profile was found also in 26.2% of frontotemporal dementia, 48.6% of Lewy body dementia, 25% of atypical parkinsonism and 44.7% of vascular dementia. Biomarkers' profile did not differ in amnestic and not amnestic mild cognitive impairment. CSF A beta levels and amyloid-PET tracer binding negatively correlated, and the concordance between the two A beta biomarkers was 89%. Conclusions The examination of the 2018 NIA-AA research framework in our clinical setting revealed a good, but incomplete, correspondence between the clinical syndromes and the underlying pathologic process measured by CSF biomarkers. The AD-continuum profile resulted to be a sensitive, but non-specific biomarker with regard to the clinical AD diagnosis. CSF and PET A beta biomarkers were found to be not perfectly interchangeable to quantify the A beta burden, possibly because they measure different aspects of AD pathology

    FORTMED | International Conference on Modern Age Fortifications of the Mediterranean Coast

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    FORTMED© è l’acronimo di Modern Age Fortifications of the Mediterranean Coast. Il principale obiettivo di FORTMED© è lo scambio e la condivisione di conoscenze, valorizzazione, gestione e fruizione della Cultura e del Patrimonio sviluppatisi lungo la costa del Mediterraneo nell’Età moderna, prendendo anche in considerazione i fenomeni che hanno avuto luogo oltremare. La disseminazione dei risultati costituisce una risorsa fondamentale per conseguire tali obiettivi
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