1,721,208 research outputs found
Variable geometry and waste-gated automotive turbochargers: measurements and comparison of turbine performance
No full textPRIMO SVILUPPO COMUNICATIVO-LINGUISTICO IN BAMBINI PRETERMINE SENZA DANNO NEUROLOGICO.
No full textThis study aimed to explore the early comunicative and language development in 10 Italian preterm infants without central nervous system insults and in 10 Italian full-term infants. All participants were assessed longitudinally
through the questionnaire “Il Primo Vocabolario del Bambino” (PVB), administered to the mothers monthly between 10 and 18 months of age.To reterm infants both chronological age and age correction for prematurity were applied. The measures derived by PVB were: gestures production, words comprehensionand production in each age.
Results – on the basis of chronological age – indicated that
preterm infants exhibited an initial and transient delay and disharmonic profiles in all aspects examined, with scores within the lower limits of typical development range. Otherwise, on the basis of age correction, preterm infants show performaces, since the first observations, on or over the mean value. In conclusion using the age correction for prematurity the communicative and language abilities of preterm infants were overestimated and the initial delay
of language development was underestimated. Findings are discussed considering the role of gestational age on early language development and the utility of correct age on the assessment of preterm infants during the second year of age
Restyling della stazione Vanvitelli. in dal duemila al futuro. architettura e infrastrutture per lo sviluppo a napoli e in campania.
No full textEffects of rail pressure control on fuel consumption, emissions and combustion parameters in a turbocharged diesel engine
No full textThe influence of rail pressure control on fuel consumption, emissions and combustion in an automotive downsized turbocharged diesel engine was investigated, considering different operating modes in three-part load working conditions. These modes were selected according to the results of a previous step of the study, where low NOX and fuel consumption levels were obtained managing a hybrid exhaust gas recirculation (EGR) system and the turbocharger variable nozzle turbine (VNT). Aiming at limiting observed soot penalties, increased values of rail pressure were applied, deepening the interactions with engine-controlled sub-assemblies and the related variations in operating, environmental, energy and combustion parameters. At low levels of engine speed and load, major reduction in NOX emissions and fuel consumption were observed, with acceptable soot and noise combustion increase, while turbocharger speed was also enhanced. No variations in fuel consumption were achieved at higher load and speed, while soot penalty remained significant. A simplified method to describe and model engine behaviour and combustion process was also developed, defining linear relationships between rail pressure and engine quantities, including a wide set of combustion parameters derived from in-cylinder pressure diagrams and heat release curves
Experimental analysis of the influence of diesel-used cooking oil methyl ester blends on efficiency, emissions and combustion process in a diesel engine
No full textAn extended investigation on the application of blends between diesel oil and used cooking oil methyl esters (UCOME) was developed on an automotive turbocharged diesel engine. Two commercial diesel oils were considered as reference fuels, the first with the conventional content of biodiesel (7%), the second with an increased amount (15%). Then, increased levels of UCOME were added, on a volumetric basis (20%, 40%, 55 or 60%), to analyze the influence of biodiesel content on engine behavior. Three part load engine operating conditions were selected for tests, measuring average engine parameters and indicated pressure diagrams. Their processing allowed to calculate the most important operating, energy and environmental engine quantities, rate of heat release and related combustion parameters. A proper management of the exhaust gas recirculation circuit, variable nozzle turbine and injection system was applied thanks to the availability of an open electronic control unit. An optimal UCOME content (40%) was identified, leading to highest values of brake thermal efficiency (with maximum increase around 5% referring to baseline fuels) and lowest levels of NOX emissions. Soot emissions were always reduced when increasing biodiesel content
Un metodo per il calcolo del lavoro d'attrito prodotto dallo stantuffo delle macchine alternative
No full text
On the approximation by product rules of weakly singular double integrals over the square
No full textDouble integrals with algebraic and/or logarithmic singularities are of interest in the application of boundary element method, e.g. linear theory of the aerodynamics of slender bodies of revolution and in many other fields, for example computational electromagnetics. Therefore, the numerical evaluation of such type of integrals deserves attention. In this connection we propose here product interpolatory rules based on suitable Jacobi zeros, giving numerical tests to show the goodness of the proposed algorithm as well as from a point of view of convergence also for the simplicity of implementation
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