182 research outputs found
Data-driven simulation of transient fields in air–coil magnets for accelerators
No full textTime-varying fields in fast-ramping magnets for accelerators are difficult to compute in the range of accuracy required for magnet operation. This is due to the complexity of the dynamic phenomena such as hysteresis and 3D eddy currents. On the other hand, magnetic measurements that intercept all these physical phenomena are often limited to a subset of excitation cycles and restricted spatial domains. The measurement results are therefore difficult to extrapolate without a validated physical model of the device. This paper proposes measurement-updated field simulations to characterize dynamic effects in accelerator magnets. The main idea is to construct a reduced-order model, whose variables are retrievable from measurements by means of a state estimator, and to update the model by minimizing the error between simulations and measurements. The proposed method is applied to a linear, time-transient electromagnetic-field problem of an air–coil corrector magnet with aluminium collars. The proposed method is a first step towards a of an accelerator magnet
Design of Energy-Saving MgB_\rm{2} Ramped Superconducting Magnets for Particle Beam Lines [Design of Energy-Saving MgB2 Ramped Superconducting Magnets for Particle Beam Lines = Design of Energy-Saving MgB]
No full textLarge accelerator facilities in the medium- and high-energy particle range can consume a significant amount of energy to power the resistive magnets in the beamlines. Depending on the magnet duty cycle, new magnet designs based on superconducting configurations have become increasingly attractive as possible alternatives to energy-intensive resistive solutions. High-temperature superconductor coils made in BCO (rare earth copper oxide) and MgB based cables can be used for both static and ramped magnets thanks to their high energy margin due to the large critical temperature. The University of Milan and INFN-Milano LASA lab. research team are currently working on developing superconducting magnet designs to replace the conventional resistive coils without modifications of the iron yoke of the normal-conducting solution. To highlight the potential of these superconducting materials, we present an estimation of the energy consumption reduction achieved in a MgB superferric dipole ramped magnet case study for the CNAO accelerator complex. Two design iterations, optimized at 10 K and 20 K, are compared with the resistive design demonstrating the benefit on total consumed energy and cost of this type of superconducting magnet solutions for large-scale research facilities
Data-driven modeling of nonlinear materials in normal-conducting magnets
No full textAccurate numerical modeling of normal-conducting accelerator magnets requires a reliable characterization of the iron saturation and hysteresis as well as a precise knowledge of the magnet geometry as built. Computations of the field quality are not easily achieving the accuracy required by the accelerator operation, particularly for eddy-current effects in fast-ramping magnets. This paper proposes a (measurement) data-driven model for the nonlinear magnetization of normal-conducting magnets. The model adopts a volume integral formulation compatible with eddy-current simulations. A two-step updating procedure is applied. The first step is the fitting of material parameters directly in the magnet model. The second step is the updating of the magnetization by measurements of the integral field harmonics. The result is a full-order updated model that can be employed in static or dynamic simulations. Finally, the procedure is validated on an iron-dominated, normal-conducting magnet
IRIS. The Italian research infrastructure on applied superconductivity for particle accelerators and societal applications
No full textThe Italian Minister for University and Research has recently funded a large program for an Innovative Research infrastructure on applied Superconductivity in Italy. Based on the LASA lab in Milan it is a partnership among: INFN (leader, participating with 4 labs: Frascati, Genoa, Milan, Salerno); CNR (SPIN institute in Genoa, Naples and Salerno); five Universities: Genoa, Milan, Naples, Salento and Salerno. The infrastructure will expand and coordinate existing infrastructures, with new state of the art instruments for: 1) characterization of new superconducting wires/tapes and cables at high field and large current; 2) for implementing the construction of innovative small scale superconducting magnets or accelerator, beam lines and detectors; 3) developing advanced instrumentation and measurements for magnets and accelerators; 4) for testing large superconducting magnets and high power transmission superconducting lines; 5) for characterization of new superconducting materials and magnetism in matter. IRIS will be a key feature for participation to future projects requiring advanced superconducting technology, like FCC or the Mun-Collider, and also for developing societal applications, especially in the energy domain and the medical sector, of technologies pursued for high-energy accelerators. The paper will illustrate the IRIS project, its 3-year development and the idea to make it an open-access infrastructure
L'Astronomo della Sala Scarlatta del Castello del Buonconsiglio di Trento: Dosso o Fogolino?
No full textL'articolo dimostra la dipendenza di un affresco del Castello del Buonconsiglio a Trento da una incisione delle 'Sorti' di Francesco Marcolini (1540), rimettendone in discussione l'attribuzione a Dosso Dossi
I sardi visti dagli inglesi e le suggestioni anglo-americane sulla classe dirigente risorgimentale
No full textIl saggio di Stefano Pira “I sardi visti dagli inglesi e le suggestioni anglo-americane sulla classe dirigente risorgimentale” ricostruisce il percorso delineato dallo sguardo straniero sugli isolani oscillante tra due estremi: da una parte un cupo pessimismo sulla possibilità che la Sardegna potesse imboccare la via della rivoluzione industriale e della democrazia liberale e dall’altra preda di un facile ottimismo cosmopolita sulla possibile inclusione dell’isola nelle sorti progressive europee. Il filosofo De Maistre, i consoli inglesi nell’isola, i viaggiatori stranieri nei loro libri e articoli veicolavano una visione semplificata dei suoi abitanti chiusi in un arcaismo considerato fuori dalla storia. Nel XIX secolo, per la prima volta, la classe dirigente sarda si oppone alla facile sintesi raggiungendo l’opinione pubblica europea e svelando la complessità di un’isola sfuggita al Grand Tour. Giorgio Asproni, deputato e giornalista, esponente di punta della nuova classe dirigente risorgimentale, attraverso intense collaborazioni a giornali nazionali e stranieri, indicherà per il Meridione e le Isole il modello politico democratico della Gran Bretagna e degli Stati Uniti d’America
Wearable biofeedback suit to promote and monitor aquatic exercises: a feasibility study
No full textAquatic exercises have been demonstrated to benefit the facilitation of motor recovery and the enhancement of well-being in middle-aged adults and the elderly. Personalization, immersiveness, and biofeedback are key for amplifying and accelerating any rehabilitation process in neurological and orthopedic patients. However, a therapist can neither properly visualize nor monitor rehabilitation exercises executed under water, nor can he/she measure them. Therefore, this paper aims to provide adaptive biofeedback during aquatic exercises in order to enhance the training's effectiveness. A wearable biofeedback suit equipped with wearable underwater-resistant sensor nodes has been designed, produced, and tested. A dedicated algorithm for quantitatively extracting joint angles has been developed and validated against the optical tracking system. Multiple biofeedback modalities are proposed based on visual feedback: amplitude control with set target angles; velocity-amplitude control with set target angles and angular velocity; and velocity tutor with set target angles, a frequency value, and a rest period. Joint angles estimated using the sensor network are compared to those estimated using an optical tracking system with the root-mean-squared angle error between the two systems ranging from 4.0° to 6.3° and a significant correlation coefficient that is always greater than 0.99. Pilot tests during aquatic exercises executed in a thermal environment demonstrate the feasibility and usability of the complete system in the final working environment. The relevant angles are correctly calculated and monitored online during the exercises, and the tested subjects understand the implemented biofeedback modalities easily and follow them well as the SUS evaluation indicates
Nonlinear Optimal Control of No-Insulation and Controlled-Insulation HTS Coils and Magnets
No full textThe IRIS project, a recently approved Italian research infrastructure, aims to advance HTS (High-Temperature Superconductors) technology for use in particle accelerators and society applications. Within this project, ongoing research focuses on developing an HTS dipole magnet, with a strong commitment on selecting the most suitable winding technology. Leading contenders include No-Insulation and Controlled-Insulation coils, known for their stability and self-protection features. However, challenges like prolonged charging times persist. This paper explores advanced techniques in Nonlinear Optimal Control theory to address this issue, through an algorithm for optimizing input current profiles using a lumped-parameters model of an HTS device. This theory enables the optimization of virtually any system by defining tailored cost functions that incorporate state variables, inputs, and outputs over time. This paper introduces these concepts to the magnet science community, offering enhanced control and automation capabilities for superconducting magnets, contributing to sustainable technology development for current and future facilitie
SADRŽAJ LIKOPENA U PLODU ODABRANIH SORTI RAJČICE (Solanum lycopersicum L.) I ANTIOKSIDACIJSKA AKTIVNOST EKSTRAKATA LIKOPENA ODREĐENA DPPH METODOM
No full textRajčica (Solanum lycopersicum L.) jednogodišnja je zeljasta biljka iz porodice
pomoćnica (Solanaceae) i potječe iz Južne Amerike. Uzgaja se u toplijim dijelovima svih
kontinenata radi plodova koji se upotrebljavaju svježi, kuhaju, konzerviraju ili prerađuju.
Osim različitih hranjivih tvari rajčica je značajan izvor biljnog pigmenta likopena iz skupine
karotenoida koji joj daje karakterističnu crvenu boju. Likopen ima izraženo antioksidativno
djelovanje te pomaže kod oksidativnog stresa i štiti organizam od djelovanja slobodnih
radikala. U ovom radu utvrđena je količina likopena u plodovima odabranih sorti rajčice
nakon ekstrakcije organskim otapalima. Ekstrakcija likopena provedena smjesom otapala
heksan : metanol : aceton (2:1:1) pokazala je najveći sadržaj likopena u sorti Enterprise od
19,72 mg/kg, a najmanju vrijednost imala je sorta Kendras od 14,24 mg/kg. Količina likopena
u ostalim ispitanim sortama Heinz , Fokker, i Increase bila je u rasponu od 19,62 mg/kg do
15,57 mg/kg. Ispitana je i antioksidativna aktivnost priređenih ekstrakata mjerenjem njihovog
utjecaja na stabilni slobodni radikal 1,1-difenil-2-pikrilhidrazil radikal (DPPH). Najveću
izmjerenu antioksidacijsku aktivnost ima ekstrakt sorte Enterprise od 28,60 ± 1,05%, a
najmanji antioksidacijski kapacitet je pokazao ekstrakt sorte Heinz od 17,52 ± 1,21
Sulla funzione del quaesitor: testi e ipotesi
No full textL’articolo mira a fare luce sulla figura del presidente di giuria nel processo criminale repubblicano.
Assumendo come punto di osservazione privilegiato le orazioni ciceroniane, il tentativo è quello di determinare il reale peso assunto dal quaesitor all’interno delle dinamiche processuali. Una specifica analisi è dedicata alla questione rimasta aperta, relativa alla possibilità per il quaesitor di incidere direttamente sulle sorti dell’imputato esprimendo il proprio voto al pari dei membri della giuria
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