52 research outputs found
Segmented Hairpin Topology for Reduced Losses at High Frequency Operations
No full textNowadays, one of the key challenges in transport electrification is the reduction of components’ size and weight. The electrical machine plays a relevant role in this regard. Designing machines with higher rotational speeds and excitation frequencies is one of the most effective solutions to increase power densities, but this comes at the cost of increased losses in cores and windings. This challenge is even more pronounced in preformed windings, such as hairpins, which enable higher slot fill factors and shorten manufacturing cycle times. In this work an improved hairpin winding concept is proposed, aiming to minimize high-frequency losses while maintaining the benefits deriving from the implementation of hairpin windings onto electrical machines. Analytical and finite element models are first used to assess the high-frequency losses in the proposed winding concept, namely the segmented hairpin, proving the benefits compared to conventional layouts. Experimental tests are also performed on a number of motorettes comprising both conventional and proposed segmented hairpin configurations. Finally, these experimental results are compared against those collected from motorettes equipped with random windings, demonstrating the competitiveness of the segmented hairpin layout even at high-frequency operations.
© 20XX IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.This paper reflects only the author's view. JU is not responsible for any use that may be made of the information it contains
Sviluppo di modelli FEM 3D per analisi dei fenomeni elettromagnetici peculiari nelle macchine sincrone
No full textL'argomento trattato è la modellazione di un turboalternatore da 470 MVA, si realizzerà un modello 3D che verrà usato poi per il calcolo numerico dei fenomeni elettromagnetici quali correnti parassite, flusso disperso alle testate e forze elettromagneticche dovute alla componente assiale del campo, la difficoltà nella modellazione consiste nel gestire la complessità reale delka macchina e adottare semplificazioni in modo da rendere un modello che non richiede molta onerosita di calcolo e che rappresenti in maniera affidabile I fenomeni
Naši preci u kontekstu književnog stvaralaštva Itala Calvina
No full textItalo Calvino è l’autore di una vasta produzione letteraria che comprende opere di ogni genere scritte in un periodo durato più di trent’anni. Nel corso della sua carriera l’autore ha rivoluzionato più volte il proprio stile e il proprio approccio alla scrittura cimentandosi in esperimenti diversi, dal neorealismo fino al postmodernismo. La sua carriera comincia con 'Il sentiero dei nidi di ragno' (1947), un romanzo che per lo più segue la corrente letteraria neorealista che si è diffusa nel periodo del dopoguerra. Dopo aver tentato invano di scrivere due altri romanzi nello stile del neorealismo, nel 1952 l’autore pubblica 'Il visconte dimezzato', il suo primo romanzo fantastico. Negli anni seguenti Calvino pubblicherà altre due ‘fiabe moderne’, 'Il barone rampante' (1957) e 'Il cavaliere inesistente' (1959), che nel 1960 verranno riunite, con 'Il visconte dimezzato', in un unico volume intitolato 'I nostri antenati'. Lo scopo di questa tesi è di definire il ruolo che la trilogia degli 'Antenati' ha avuto nell’evoluzione dello stile di Calvino, individuando i temi e gli elementi stilistici che vengono riproposti dall’autore nelle sue altre opere e mettendole a confronto con le storie della trilogia. Esaminando 'I nostri antenati' possiamo intravedere già l’inclinazione alla letteratura labirintica e autoriflessiva che porterà Calvino all’avanguardia del postmodernismo negli anni ’60 e che definirà la sua produzione letteraria nei prossimi due decenni con opere sperimentali come 'Le cosmicomiche', 'Le città invisibili', 'Il castello dei destini incrociati', 'Se un una notte d’inverno un viaggiatore' e 'Palomar'. I temi ricorrenti della sua produzione letteraria che vengono sottolineati nella tesi sono: la precaria posizione dell’individuo nella società moderna, la presa di distanza dalla realtà, la demistificazione della scrittura e del linguaggio, e l’impossibilità di trovare risposte certe sul significato e sulla realtà del mondo, usando modelli universali. Questi temi sono già presenti nelle storie degli 'Antenati', ma alcuni di essi vengono elaborati in modi più sofisticati nelle opere seguenti di Calvino; specialmente l’esplorazione dei limiti del linguaggio e dei sistemi razionali classici, che verranno interrogati rigorosamente nelle sue opere degli anni ’70 e ’80.Italo Calvino is the author of a vast literary production that includes works of various genres written over a period that spans more than thirty years. Over the course of his career, the author has revolutionized his style and his approach to writing several times, engaging in various experiments, from neorealism to postmodernism. His career begins with The Path of Spider's Nests (1947), a novel that mostly follows the neorealist literary current that spread in the post-war period. After trying in vain to write two other novels in the neorealist style, in 1952 the author published The Cloven Viscount, his first fantasy novel. In the following years Calvino will publish two other 'modern fairy tales', The Baron in the Trees (1957) and The Nonexistent Knight (1959), which in 1960 will be collected with The Cloven Viscount in a single volume entitled Our Ancestors. The purpose of this thesis is to define the role that the trilogy of the Ancestors had in the evolution of Calvino's style, by identifying the themes and stylistic elements that are reproposed by the author in his other works and comparing them with the stories of the trilogy. By examining our ancestors we can already glimpse the inclination to labyrinthine and self-reflective literature that will lead Calvino to the forefront of postmodernism in the 1960s and that will define his literary production in the next two decades with experimental works such as Cosmicomics, Invisible Cities, The Castle of Crossed Destinies, If on a Winter's Night a Traveler and Mr. Palomar. The recurring themes of his literary production that are underlined in the thesis are: the precarious position of the individual in modern society, the taking of distance from reality, the demystification of writing and language, and the impossibility of finding certain answers on the meaning and the reality of the world using universal models. These themes are already present in the stories of the Ancestors, but some of them get elaborated in more sophisticated ways in Calvino’s following works; especially the exploration of the limits of language and classical rational systems, which will be rigorously questioned in his works from the 70s and 80s.Italo Calvino autor je znatne književne produkcije koja uključuje djela raznovrsnih žanrova napisana u razdoblju koje je trajalo više od trideset godina. Tijekom svoje karijere autor je više puta revolucionirao svoj stil i pristup pisanju, okušavši se u različitim eksperimentima, od neorealizma do postmodernizma. Njegova karijera započinje s romanom Staza do paukovih gnijezda (1947.), koji uglavnom prati neorealističku književnu struju koja se proširila u poslijeratnom razdoblju. Nakon što je uzalud pokušao napisati još dva romana u stilu neorealizma, autor je 1952. objavio svoj prvi fantastični roman, Raspolovljeni viskont. Sljedećih godina Calvino će objaviti još dvije 'moderne bajke', Barun penjač (1957.) i Nepostojeći vitez (1959.), koje će 1960. biti okupljene, zajedno s Raspolovljenim viskontom, u jedan svezak pod naslovom Naši preci. Cilj ovog rada je definirati ulogu koju je trilogija Naši preci imala u razvoju Calvinovog stila, utvrđivanjem tema i stilskih elemenata koje je autor ponovno obradio u svojim ostalim djelima te usporediti ih s pričama trilogije. Ispitivanjem Naših predaka već možemo nazrijeti sklonost labirintnoj i promišljenoj književnosti koja će Calvina 60-ih godina 20. stoljeća postaviti u avangardu postmodernizma i koja će definirati njegovu književnu produkciju u sljedeća dva desetljeća eksperimentalnim djelima poput Kozmikomike, Nevidljivi gradovi, Dvorac ukrštenih sudbina, Ako jedne zimske noći neki putnik i Palomar. Teme koje se ponavljaju u toku njegove književne produkcije koje se ističu u radu su: nesiguran položaj pojedinca u suvremenom društvu, udaljivanje od stvarnosti, demistifikacija pisma i jezika te nemogućnost pronalaženja sigurnih odgovora za značenje i stvarnost svijeta koristeći univerzalne metode. Ove su teme već prisutne u pričama Predaka, ali neke od njih su na vještiji način razrađene u sljedećim Calvinovim djelima; osobito istraživanje granica jezika i klasičnih racionalnih sustava, koje će biti rigorozno dovedene u pitanje u njegovim djelima 70-ih i 80-ih godina
Aspects of sea navigation
No full textThis paper investigates three topics which play a role in the adjustment and testing of offshore navigation data. All these three aspects are more or less related to the NAVGRAV project (NAVigation-GRAVitation) which will take place in 1986. First, the preci si on of various radiopositioning systems is elaborated. For the computation of the precision a design matrix and a covariance matrix are needed. Three different ways to derive a covariance matrix for a hyperbolic system are given, 1) the derivation by Strang van Hees, 2) the derivation by Nicolai and 3) an extended version of these two derivations. Chapter 1 ends with some pictures of the precision of Hyperfix, Hifix/6 Syledis and Pulse/8 in selected areas.Civil Engineering and Geoscience
Hairpin Windings: Sensitivity Analysis and Guidelines to Reduce AC Losses
No full textAbstract— Nowadays, electrification in the transportation sector is one of the most viable solutions to reduce CO2 emissions
and meet fuel economy requirements. Being the electrical machine one of the most important players in this electrification
trend, extensive research is currently being dedicated to the improvement of their efficiency and power density. In
automotive applications, hairpin technologies are widely spreading due to their potential in reducing costs and life cycles
in a mass production perspective, as well as in increasing the torque capabilities of machines. However, several challenges
need to be addressed before the complete replacement of random windings with hairpins can take place. Of these
challenges, the loss produced during high frequency operations is one of the most limiting. This paper aims at studying and
investigating high frequency (AC) losses for different slot geometries and conductor cross sections, which in turn involve the analysis of different slots-per-pole-per-phase / layers-perslot combinations. In addition, the effects on the AC losses of
reducing the slot fill factor are studied, either by removing the closest conductors to the slot opening or by reducing the hairpin legs’ height. Analytical and numerical models are employed to investigate these concepts.
© 20XX IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.This paper reflects only the author's view. JU is not responsible for any use that may be made of the information it contains
Dalle preci alle armi. Un'inedita notizia ecclesiastica su Alessandro Sforza, Signore di Pesaro
No full textThe author studies and publishes three documents from the Libri Annatarum, one of the most important sources of the Camera Apostolica, concerning the archdeaconry obtained from a young gentleman, Alessandro Sforza, future Lord of Pesaro, in Benevento in the 20’s of the 15th century
Lifestyle advertising in magazine Cosmopolitan (January 2008 - December 2008)
No full textBakalaura darbs “Dzīves stila reklāma žurnālā “Cosmopolitan” (2008.gada janvāris – 2008. gada decembris)” pievēršas tādai masu komunikācijas tēmai kā dzīves stila reklāma.
Mūsdienu reklāmas pasaule ir tik dažāda un bagātīga ar patērētāju piesaistīšanas paņēmieniem. Tomēr ir reklāmas formāts, kas pārdod nevis preci, bet gan dzīves stilu. Patērētājs, iegādājoties kādu preci iedomājas, ka iegūst sev jaunu statusu. Tomēr vai tas tā ir? Vai arī reklāma meistarīgi spēlē ar cilvēku prātiem?
Bakalaura darba teorētiskajā daļā tiek apskatīta reklāmas teorija un dzīves stila koncepcija, kā arī tās attēlojumi reklāmā.
Darba pētnieciskā daļa apskata žurnāla “Cosmopolitan” reklāmas 2008. gadā, koncentrējoties tieši uz dzīves stila reklāmām. Pētnieciskā daļa satur kontentanalīzi un semiotisko analīzi.
Atslēgvārdi: Cosmopolitan; reklāma; dzīves stils.The following Bachelor’s paper “Lifestyle advertising in magazine Cosmopolitan(January 2008 – December 2008)” is about one of the mass communication themes - lifestyle advertising.The basic idea of the work was to understand what is lifestyle advertising and how it works and influences consumers.
In the theoretical part of the work author looks at advertising theory un the concept of
lifestyle and its depictions in ads.
The empirical part of the work offers the content analysis and semiotic analysis of the ads
from the magazine Cosmopolitan.
Keywords: Cosmopolitan; ad; lifestyle
Review of the transfer of risk from seller to purchaser under UN Convention on Contracts for the International Sales of Goods
No full textRisks ir viens no centrālajiem un galvenajiem elementiem starp pusēm starptautiskos darījumos. Turklāt tas ir arī viens no sarežģītākajiem darījumu elementiem, kas noteikti 1980. gada ANO Konvencijā par starptautiskajiem preču pirkuma - pārdevuma līgumiem. Darbā tiek analizēta riska pāreja situācijās, kad pārdevējs piegādā līgumam neatbilstošu preci, kā arī gadījumos, kad pārdevējs preci piegādā pirms līgumā norunātā termiņa; autore pievēršas arī risku veidu analīzei; tāpat tiek analizēts arī jēdziens “garantija”, proti, kā garantija ietekmē riskus. Tāpat darbā tiek analizēta un nošķirta riska ietekme uz pircēju un pārdevēju, kā arī tiek apskatīti tiesiskās aizsardzības līdzekļi, ko puses izmanto strīda gadījumos. Atslēgvārdi: atbildība; CISG; riska pāreja; neatbilstoša prece.The risk is one of the central and key elements between parties in international transactions. In addition, it is also one of the most complex elements of transactions, which were established in 1980 in United Nations Convention on the Contracts for the International Sale of Goods (CISG). The transfer of risk is analyzed in situations where the seller delivers goods non-compliant with the contract, as well as in cases where the seller delivers goods before the deadline agreed in the contract; the author also focuses on the analysis of types of risks; the concept “guaranty” is also analyzed, namely, in what way the guarantee affect risks. Similarly, the effect of risk to buyers and sellers is analyzed and separated in the paper, as well as the legal remedies used by the parties in the dispute cases are viewed. Keywords: liability; CISG, risk transfer, unconformity of goods
Influence of Rotor Design on Electromagnetic Performance in Interior Permanent Magnet Machines
No full textCapSeat- Capacitive Proximity Sensing for Automotive Activity Recognition
No full textInattentiveness is one of the major causes of traffic accidents. Advanced car safety systems try to mitigate this by detect-ing potential signs of distraction or tiredness, and providing alerts to the driver. In this paper we present CapSeat- a car seat equipped with integrated capacitive proximity sensors that are used to measure a wide range of physiological pa-rameters about the driver. This can support safety systems by detecting inattentiveness and increase passive safety by facilitating suitable seat adjustments and posture detection. We present a sensor electrode layout suitable for detecting the necessary parameters and processing methods that acquire multiple physiological parameters from sensor data, using a variety of different algorithms. A prototype of the system is presented that was evaluated for all detectable parameters in a proof-of-concept study. We achieved a classification preci-sion between 95 % and 100%. Author Keywords Car seat; capacitive proximity sensing; driver safety; classificatio
- …
