638 research outputs found
Experimental Characterization of a Belt-Driven Multi-Phase Induction Machine for 48 V Automotive Applications: Losses and Temperatures Assessments
No full text[134] A. Cavagnino, A. Tenconi, S. Vaschetto, "Experimental Characterization of a Belt-Driven Multi-Phase Induction Machine for 48 V Automotive Applications: Losses and Temperatures Assessments", Conf. Rec. , , ISBN: , 2014, pp. 1165-117
PM fractional machines adopting bonded magnets: effect of different magnetizations on the energetic performance
No full textThe adoption of Permanent Magnets in small brushless machines for automotive applications is becoming frequent. Some research on bonded magnets is being carried on to substitute the ferrites. In the paper the parallel and radial magnetizations are considered: the different process complexity levels are analyzed and the effects on the iron losses and the energetic performances are evaluated by means of a simulation analysis and its experimental validatio
Re: "parity and the risk of Down's syndrome".
No full textRE: “PARITY Doria-Rose e At aNl.D (1 T) HreEce RnItlSyK e xOaFm DinOedW pNar’iSty S aYsN aD riRskO fMacEto”r
for Down’s syndrome and concluded that their data support an
association between parity and Down’s syndrome at any age.
However, as Chan (2) pointed out in the invited commentary
that accompanied this Journal article, the Doria-Rose et al.
paper suffers from some limitations, such as ascertainment of
Down’s syndrome births and lack of data on prenatal diagnosis.Our data confirm a higher risk of a Down’s syndrome
child limited to only those women with a parity of more than
four. However, because this effect is evident for women only
35 years of age or older, its practical impact is null because
these women are usually offered prenatal diagnosis in any
case. However, understanding the mechanisms involved, if
this association is true, is very intriguing and could stimulate
scientific studies allowing better knowledge of the nondisjunction
mechanisms
Evaluation of the magnetization direction effects on ferrite PM brushless fractional machines
No full textPermanent magnets are frequently adopted in small brushless machines for automotive applications. Normally anisotropic ferrites, but some research on bonded magnets is being carried on. Several types of magnetization can be proposed, involving different levels of complexity in the magnetization process. In the paper a comparison between parallel and radial magnetization is described, taking into account on one side the major complexity of the radial process and on the other the small power derating of the paralle
Functionalized dithioester and dithiocarbamato complexes of platinum(II) halides
No full textPlatinum dihalides react with the dithioester EtO2CCH2(CH3)NCS2Me (ESDTM) yielding the complexes Pt(ESDTM)X-2 and trans-Pt(ESDTM)(2)X-2 (X = Cl or Br). In the 1:2 adducts the ligand acts as monodentate through the thiocarbonyl sulfur, whereas it is S,S chelated in the Pt(ESDTM)X-2 species. These complexes release easily methyl halide either in solid or in solution to form species containing the related dithiocarbamato moiety (ESDT, EtO2CCH2(CH3)NCS2-). The first decomposition step in thermal degradation of the Pt(ESDTM)X-2 complexes involves evolution of one methyl halide molecule to form the related [Pt(ESDT)X](n) intermediate and leading finally to platinum metal. In the same conditions the trans-Pt(ESDTM)(2)X-2 complexes undergo demethylation of both ligand molecules, the Pt(ESDT)(2) intermediate being stable up to 250 degrees C. The dithioester adducts and the related degradation intermediates have been characterized by elemental analyses and IR and H-1 NMR spectroscopy. The complex behaviour in Various solvents has been described by proton NMR data
La Milano Moderna di Piero Bottoni 1954 - 2014. Storia e attualità di un patrimonio architettonico e urbano
No full textA sessant'anni di distanza dalla prima edizione dell'Antologia di Piero Bottoni, la selezione di edifici moderni pubblicata nel 1954 continua a costituire una rassegna significativa dell'architettura milanese del primo Novecento. Una rassegna rappresentativa del percorso che ha accompagnato la nascita e l'affermazione del movimento razionalista, ma anche un'illustrazione esemplare della prima storicizzazione di questa esperienza da parte della cultura architettonica del secondo dopoguerra.
Ripercorrere oggi l'itinerario proposto da Bottoni costituisce un viaggio alle radici di quella stagione creativa che ha reso la Milano degli anni Cinquanta e Sessanta un punto di riferimento internazionale per l'architettura e per il design, ma fornisce anche l'occasione di misurare direttamente le trasformazioni che questo patrimonio ha subito in oltre mezzo secolo di vita.
Il senso ultimo di questo libro − frutto del laboratorio Milano Moderna avviato nel 2009 all'interno di un corso di Storia dell'architettura contemporanea del Politecnico di Milano − è infatti quello di sensibilizzare studenti, cittadini e turisti all'uso consapevole di un patrimonio architettonico e urbano che appartiene a tutti e che deve poter accogliere le sfide dell'attualità senza tradire la propria identità materiale e culturale
Direct torque control for dual three-phase induction motor drives
No full textA direct torque control (DTC) strategy for dual three-phase induction motor drives is discussed in this paper. The induction machine has two sets of stator three-phase windings spatially shifted by 30 electrical degrees. The DTC strategy is based on a predictive algorithm and is implemented in a synchronous reference frame aligned with the machine stator flux vector. The advantages of the discussed control strategy are constant inverter switching frequency, good transient and steady-state performance, and low distortion of machine currents with respect to direct self-control (DSC) and other DTC schemes with variable switching frequency. Experimental results are presented for a 10-kW DTC dual three-phase induction motor drive prototype
New Stationary Frame Control Scheme for Three Phase PWM Rectifiers Under Unbalanced Voltage Dips Conditions
No full textA new stationary frame control scheme for three-phase pulsewidth-modulation (PWM) rectifiers operating under unbalanced voltage dips conditions is proposed in this paper. The proposed control scheme regulates the instantaneous active power at the converter poles to minimize the harmonics of the input currents and the output voltage ripple. This paper's novelty is the development of a new current-reference generator implemented directly in stationary reference frame. This allows using proportional sinusoidal signal integrator (P-SSI) controllers for simultaneous compensation of both positive and negative current sequence components. No phase-locked loop (PLL) strategies and coordinate transformations are needed for the proposed current-reference generator. Experimental results are presented for a 20-kV A alternative current (ac)/direct current (dc) converter prototype to demonstrate the effectiveness of the proposed control scheme. A comparison with two other existing control techniques is also performed. Fast dynamic performance with small dc-link voltage ripple and input sinusoidal currents are obtained with this control scheme, even under severe voltage dips operating condition
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