Nuclear magnetic resonance | Wikipedia audio article
Channel: wikipedia tts
Date: 2018-12-08

This is an audio version of the Wikipedia Article:
Nuclear magnetic resonance


00:04:12 1 History
00:06:26 2 Theory of nuclear magnetic resonance
00:06:37 2.1 Nuclear spin and magnets
00:10:44 2.2 Values of spin angular momentum
00:12:10 2.2.1 Spin energy in a magnetic field
00:12:29 2.2.2 Precession of the spin magnetization
00:15:42 2.2.3 Magnetic resonance and radio-frequency pulses
00:18:01 2.2.4 Chemical shielding
00:19:25 2.3 Relaxation
00:21:38 3 NMR spectroscopy
00:24:15 3.1 Continuous-wave (CW) spectroscopy
00:25:48 3.2 Fourier-transform spectroscopy
00:28:19 3.3 Multi-dimensional NMR spectroscopy
00:30:53 3.4 Solid-state NMR spectroscopy
00:33:28 3.5 Sensitivity
00:36:41 3.6 Isotopes
00:39:55 4 Applications
00:44:45 4.1 Medicine
00:45:17 4.2 Chemistry
00:46:49 4.3 Purity determination (w/w NMR)
00:49:16 4.4 Non-destructive testing
00:52:04 4.5 Segmental and molecular motions
00:52:48 4.6 Data acquisition in the petroleum industry
00:53:41 4.7 Flow probes for NMR spectroscopy
00:56:16 4.8 Process control
00:56:48 4.9 Earth's field NMR
00:58:07 4.10 Zero field NMR
00:59:55 4.11 Quantum computing
01:00:57 4.12 Magnetometers
01:01:21 4.13 SNMR
01:01:45 5 Makers of NMR equipment
01:02:18 6 See also



Listening is a more natural way of learning, when compared to reading. Written language only began at around 3200 BC, but spoken language has existed long ago.

Learning by listening is a great way to:
- increases imagination and understanding
- improves your listening skills
- improves your own spoken accent
- learn while on the move
- reduce eye strain

Now learn the vast amount of general knowledge available on Wikipedia through audio (audio article). You could even learn subconsciously by playing the audio while you are sleeping! If you are planning to listen a lot, you could try using a bone conduction headphone, or a standard speaker instead of an earphone.

You can find other Wikipedia audio articles too at:
https://www.youtube.com/channel/UCuKfABj2eGyjH3ntPxp4YeQ

You can upload your own Wikipedia articles through:
https://github.com/nodef/wikipedia-tts



"The only true wisdom is in knowing you know nothing."
- Socrates



SUMMARY
=======
Nuclear magnetic resonance (NMR) is a physical phenomenon in which nuclei in a strong static magnetic field are perturbed by a weak oscillating magnetic field (in the near field and therefore not involving electromagnetic waves) and respond by producing an electromagnetic signal with a frequency characteristic of the magnetic field at the nucleus. This process occurs near resonance, when the oscillation frequency matches the intrinsic frequency of the nuclei, which depends on the strength of the static magnetic field, the chemical environment, and the magnetic properties of the isotope involved; in practical applications with static magnetic fields up to ca. 20 tesla, the frequency is similar to VHF and UHF television broadcasts (60–1000 MHz). NMR results from specific magnetic properties of certain atomic nuclei. Nuclear magnetic resonance spectroscopy is widely used to determine the structure of organic molecules in solution and study molecular physics, crystals as well as non-crystalline materials. NMR is also routinely used in advanced medical imaging techniques, such as in magnetic resonance imaging (MRI).
All isotopes that contain an odd number of protons and/or neutrons (see Isotope) have an intrinsic nuclear magnetic moment and angular momentum, in other words a nonzero nuclear spin, while all nuclides with even numbers of both have a total spin of zero. The most commonly used nuclei are 1H and 13C, although isotopes of many other elements (e.g. 2H, 6Li, 10B, 11B, 14N, 15N, 17O, 19F, 23Na, 29Si, 31P, 35Cl, 113Cd, 129Xe, 195Pt) have been studied by high-field NMR spectroscopy as well.
A key feature of NMR is that the resonance frequency of a particular simple substance is usually directly proportional to the strength of the applied magnetic field. It is this feature that is exploited in imaging techniques; if a sample is placed in a non-uniform magnetic field then the resonance frequencies of the sample's nuclei depend on where in the field they are located. Since the resolution of the imaging technique depends on the magnitude of the magnetic field gradient, many efforts are made to develop increased gradient field strength. 
The principle of NMR usually involves three sequential steps:

The alignment (polarization) of the magnetic nuclear spins in an applied, constant magnetic field B0.
The perturbation of this alignment of the nuclear spins by a weak oscillating magnetic field, usually referred to as a radio-frequency (RF) pulse. The oscillation frequency required for significant perturbation is dependent upon the static magnetic field (B0) and the nuclei of observation.
The detection of the NMR signal during or after the RF pulse, due to the voltage induced in a detection coil by precession of the nuclear spins  ...