Motori Elettrici Lineari ad Elevata Spinta per Applicazioni Navali

Gli attuatori oleodinamici usati per timonerie e pinne stabilizzatrici sviluppano elevate coppie a basse velocit\ue0. Viene presentato, in alternativa, un innovativo motore elettrico lineare ad elevata spinta alimentato da inverter per azionamenti diretti a bordo nave, che offre grandi vantaggi in termini di compattezza, manutenzione, efficienza, e tolleranza al guasto

Spazio pubblico e attrattività urbana. L'Isola e le sue piazze

L’Isola e le sue piazze è un progetto di valorizzazione urbana integrata promosso nel gennaio 2015 da Comune di Milano, Regione Lombardia e Distretto urbano del commercio Isola, volto a promuovere l’identità del quartiere Isola, attraverso la realizzazione di arredi temporanei, eventi e un piano di comunicazione. Entro tale contesto, un gruppo multidisciplinare di ricerca del Politecnico di Milano afferente ai dipartimenti di Architettura e Studi Urbani e di Design, attraverso mappature e rilievi, osservazione diretta e interviste, ha condotto un lavoro di accompagnamento e monitoraggio della proposta risultata vincitrice del bando pubblico. Il volume restituisce gli esiti della ricerca: descrive lo sfondo entro cui è maturato il progetto, racconta le specificità del quartiere, la qualità del suo spazio pubblico, le geografie dell’offerta economica. I testi degli autori della ricerca si intrecciano alle voci di abitanti, di testimoni privilegiati, di rappresentanti delle istituzioni e dell’associazionismo locale che a vario titolo sono stati coinvolti dal progetto, con l’obiettivo di riflettere sulle molteplici dimensioni dello spazio pubblico e dell’attrattività urbana: dagli usi formali e informali ai servizi commerciali di prossimità, dagli eventi che hanno avuto luogo nel periodo osservato alle dinamiche che hanno innescato, fino agli esiti di un inedito bando e alle opportunità della sua replicabilità

Analytical Computation of End-Coil Leakage Inductance of Round-Rotor Synchronous Machines Field Winding

3noThe computation of end coil leakage inductances of electric machines is a challenging task due to the complicated leakage flux 3D distribution in the winding overhang region. In this paper the problem is addressed of computing the field circuit leakage inductance of round-rotor synchronous machines. The proposed method is fully analytical and descends from the symbolical solution of Neumann integrals applied to the computation of self and mutual inductances combined with the method of mirror images to account for core effects. With respect to existing analytical approaches, the methodology requires neither numerical integral solutions nor discretizing the end-coil geometry into small straight elements. The accuracy of the proposed technique for computing the mutual inductance between two single end turns is assessed against measurements on a dedicated experimental set-up. The extension of the method to the computation of the entire field-circuit end-coil leakage inductance is assessed by comparison with 3D finite element analysis (FEA).Pubblicato online nel settembre 2015 e pubblicato su carta nel febbraio 2016partially_openopenBortolozzi, Mauro; Tessarolo, Alberto; Bruzzese, ClaudioBortolozzi, Mauro; Tessarolo, Alberto; Bruzzese, Claudi

Statistics for the analysis of molecular dynamics simulations : providing P values for agonist-dependent GPCR activation

Molecular dynamics (MD) is the common computational technique for assessing efficacy of GPCR-bound ligands. Agonist efficacy measures the capability of the ligand-bound receptor of reaching the active state in comparison with the free receptor. In this respect, agonists, neutral antagonists and inverse agonists can be considered. A collection of MD simulations of both the ligand-bound and the free receptor are needed to provide reliable conclusions. Variability in the trajectories needs quantification and proper statistical tools for meaningful and non-subjective conclusions. Multiple-factor (time, ligand, lipid) ANOVA with repeated measurements on the time factor is proposed as a suitable statistical method for the analysis of agonist-dependent GPCR activation MD simulations. Inclusion of time factor in the ANOVA model is consistent with the time-dependent nature of MD. Ligand and lipid factors measure agonist and lipid influence on receptor activation. Previously reported MD simulations of adenosine A2a receptor (A2aR) are reanalyzed with this statistical method. TM6-TM3 and TM7-TM3 distances are selected as dependent variables in the ANOVA model. The ligand factor includes the presence or absence of adenosine whereas the lipid factor considers DOPC or DOPG lipids. Statistical analysis of MD simulations shows the efficacy of adenosine and the effect of the membrane lipid composition. Subsequent application of the statistical methodology to NECA A2aR agonist, with resulting P values in consistency with its pharmacological profile, suggests that the method is useful for ligand comparison and potentially for dynamic structure-based virtual screening

Protection of vaccine preventable diseases in a population of hiv-infected children: A 3 years prospective study

Human Immunodeficiency Virus (HIV) infected children have a 30–70% chance of being incompletely immunized and may not respond serologically with the same magnitude or durability as uninfected children. The aim of the study was to describe the rate of protective antibodies titre and the persistence of the response against four recommended vaccinations in HIV infected children and adolescents. A two-phase observational study was performed in which protective IgG antibodies to measles, mumps, rubella and hepatitis B were determined and monitored for 12 and 24 months, in 26 perinatally HIV-infected children. The rate of protection for rubella and hepatitis B was significantly lower in the HIV group compared to the control group (92% vs. 65% for rubella and 78.4% vs. 45.4% for hepatitis B; p < 0.05). Children who received primary vaccination after initiating combination antiretroviral therapy (cART) had a higher rate of response. Seronegative patients who received a booster dose of vaccine had a good immunological response. HIV infection is associated with a lower response to vaccines against rubella and hepatitis. The beginning of cART before vaccination may be associated with a better response. The evaluation of the serological response is crucial in children with HIV infection in order to evaluate the protection of vaccine preventable diseases

Experimental and Theoretical Analysis of Non-linear Vibrational Relaxation of Polyatomic Molecules Strongly Excited by Resonant Laser Radiation

We present a very simple theoretical model aimed at the analysis of non-linear relaxation processes in molecular gases in the presence of partial molecular dissociation induced by vibrational–vibrational exchange between highly excited molecules. The model has a phenomenological character, since it analyzes the behavior of a system of anharmonic diatomic molecules, which is a very rough approximation of a polyatomic molecule such as SF6. Nonetheless, it provides an interesting key for the interpretation of a number of peculiar features characterizing our experimental observation, with which a comparison is made. In particular, the model takes realistic account of the influence of dissociation processes on the relaxation time