Sumários
Evolution of magnetization in the rotating frame after a Pi and a Pi/2 pulse
13 maio 2019, 13:00 • João Luís Maia Figueirinhas
Solution of the Bloch equations in the rotating reference frame after the application of a Pi and Pi / 2 RF pulses . Measurement of spin-lattice T1 and spin-spin T2 relaxation times.
Bloch equations
7 maio 2019, 15:00 • João Luís Maia Figueirinhas
Bloch equations in the laboratory and in the rotating reference frames. Solution of the Bloch equations in the rotating reference frame in the resonance condition and in the presence of the radio frequency field B1.
Introduction to Nuclear Magnetic Resonance techniques applied to the study of liquid crystals
6 maio 2019, 13:00 • João Luís Maia Figueirinhas
Energy levels of a nuclear spin in the presence of an external induction field. Magneto-gyric relationship. Movement of a magnetic moment in the presence of an external induction field. Larmor precession frequency.
X-ray diffraction patterns in liquid crystalline phases
30 abril 2019, 15:00 • João Luís Maia Figueirinhas
Analysis of the X-ray diffraction patterns obtained in polydomain samples and partially aligned samples in different liquid crystalline mesophases; nematic mesophase (N), smectic A (SA) and C mesophases for different molecular alignment types. Columnar mesophases.
X-ray diffraction by non-crystalline samples
29 abril 2019, 13:00 • João Luís Maia Figueirinhas
X-ray diffraction in terms of the electron density function, relationship between the diffraction pattern and the electron density autocorrelation function.