MOSEM 2 in Italy

1. MOSEM2 in Italy Marisa Michelini, Lorenzo Santi, Alberto Stefanel Research Unit in Physics Education University of Udine Michelini, Santi, Stefanel

2. Teacher Seminars in Italy Michelini, Santi, Stefanel

3. Teacher Seminars in Italy • 20 schools in 15 different Italian cities (around Udine. Bolzano, Treviso, Cosenza, Crotone) • 71 teachers (30 women, 41 men). • Udine 5 sessions Feb-May10 & 2 sec. Dec10-Jan11) • Cosenza 3+2 sess. Dec 09-Jan10 & 1 sec May11 • Crotone 3 sess. May11 • Treviso 3 sess. Feb-Mar10 • Bolzano 3 sess. Feb-Mar10. Each session: 3-4 hours. Michelini, Santi, Stefanel

4. Michelini, Santi, Stefanel

5. Teacher Seminars in Italy • CK & PCK questionnaire Michelini, Santi, Stefanel

6. Teacher Seminars in Italy • CK & PCK questionnaire Michelini, Santi, Stefanel

7. Teacher Seminars in Italy • CK & PCK questionnaire Michelini, Santi, Stefanel

8. Teacher Seminars in Italy • From experiment to model • 1) Aim: observing a phemonena design an experiment, compare results and model • Phenomenon (i.e a magnetfalling inside a coil) • Defineaspects to be described (afteridentific. Importantprocess) • Theorethicalreference law • Variables to be measured Michelini, Santi, Stefanel

9. Teacher Seminars in Italy • From experiment to model •  Aim: build a physical model for the phenomenon (i.e a magnetfalling inside a cupper tube) • Starting from experimentalresults: • Defineaspects to be modeled (afteridentific. Importantprocess) • Theorethicalreference law • Variables to be included in the module • Correlationbetweenvariables and map • Implementation of the model (pen and paper; sw-environment • Educational hint Michelini, Santi, Stefanel

10. MOSEM-MOSEM2 material Exhibits Michelini, Santi, Stefanel

11. Experimentation with students in Italy Michelini, Santi, Stefanel

12. Experimentation in:Pigelleto Summer School • 5h (large group activity and little group reflection)+1h (resumen/presentation) • 1) magn intercation; B fiel line (superposiion); magnetic suspenction • 2) levitation of a magnet on a SC • 3) em induction processes • 4) Phenomenological models for Meissner effect • 5) pinning, pinning vs Meissner and MAGLEV Michelini, Santi, Stefanel

13. Worksheets for students Michelini, Santi, Stefanel

14. The students models • Students Group 1 – EM Induction: a magnet fall inside a copper tube • 1.1) free fall t1 vs fall inside the tube t2 • 1.2) answer: why change time? From which parameters is depending? • 1.3) Ein= Pot.En • 1.4) Einterm= Kin En = cost! (unif. Motion) • 1.5) Epot  pass to the copper via em induction process (producing constant field) Michelini, Santi, Stefanel

15. The students models • Students Group 1 – EM Induction: a magnet fall inside a copper tube • 1.6) Extrem case: the magnet will be stopped • 1.7) Many factors: conductivity, magnet parameters (shape, strenght), temperature) • 1.8) “Assuming extreme conditions: if magnet stop DEnp=0  no energy transfer to the tube; the copper tube disperse the generated electric current  the magnet re-start to fall-down". • 1.9) “T affect the state of the mulecules and conductiviti decrease when T decreaese”. Michelini, Santi, Stefanel

16. The students models • Students Group 2 – Pinning. • 2.1) At T=Tamb we put on an YBCO sample a magnet. The field lines are not affected • 2.2) The LN cools YBCO ..flux of electrons in the YBCO that generate a B flusso • 2.3) At T<TLN: the YBCO became SC and for that the B of the magnet produce a flux of electrons. That flus crate the attractive effect. • 2.4) «Resistivity goes to zero: there is no more friction and there is no more resistence. Michelini, Santi, Stefanel

17. The students models • Students Group 2 – Pinning. • 2.5) Differences pinning and Meissner: • Different YBCO (different properities). • The SC do not contrast the B. It has the capability to memorize the distance [between magnet and SC] • There is an «interaction between magnetic fields» Michelini, Santi, Stefanel

18. The students models • Students Group 3 – Meissner. • 3.1) «From observation: teacking YBCO under Tc the field produced by it is opposite to the magnetic field”. • 3.2) “With few tests the magnet stand at equilibrium over the SC”. • 3.3) “We observe with different magnets”. Michelini, Santi, Stefanel

19. The students models • Students Group 3 – Meissner. • 3.4)”The magnet rotates only around his axes” • 3.5) “If we turn the [SC] disk, the disk do not create the counter-magnetism, and the magnet do not remains at equilibrium. Michelini, Santi, Stefanel

20. The students models • Students Group 4 – MAGLEV train. • 4.1) The levitation of the MAGLEV Train is based on pinning-effect • 4.2) Craeting SC interposing a separator between magnet and Sc • 4.3) «At T=Tamb nothing happens». • 4.4) «after fulling the train of LN the disc has brought to SC. With separatormemory of distance. It flows over the track. Friction just by air". Michelini, Santi, Stefanel

21. The students models • Students Group 4 – MAGLEV train. • 4.5) «The train have memory that he must come back» • 4.6) «If the preparation procedure is realized apart: levitation due to Meissner effect; it has problem to come back as the magnet» • 4.7) SC in the everyday life: trains in Giapan and Germany. Michelini, Santi, Stefanel

22. The students models • Students Group 4 – MAGLEV train. • 4.8) Role of the track: Track sud-nord-sud on the transversal direction. Track with the same polariti on the left-right direction («recognized exploring directly with a magnet») Michelini, Santi, Stefanel

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