File:Gradient Echo (expand the description below for a detailed explanation).webm
Jump to navigation
Jump to search
No higher resolution available.
Gradient_Echo_(expand_the_description_below_for_a_detailed_explanation).webm (WebM audio/video file, VP8/Vorbis, length 36 s, 256 × 240 pixels, 179 kbps overall, file size: 788 KB)
Captions
Captions
Add a one-line explanation of what this file represents
Summary
[edit]| Description |
English: Field gradients are not just useful for discriminating between signals spatially, they can also be used to create an echo. Here, the RF pulse rotates the protons into the XY-plane. The net dipole starts large, but eventually decays since the protons experiencing the greater magnetic field are precessing faster.
However, later, the gradient changes direction. The protons that were precessing slower and got behind are now the fast ones, while the protons that were fast and got ahead are now slow. Eventually, they become realigned and the net dipole becomes large again, creating another measurable signal called an echo. |
| Date | |
| Source | YouTube: Gradient Echo (expand the description below for a detailed explanation) – View/save archived versions on archive.org and archive.today |
| Author | Tyler Moore |
Licensing
[edit].svg){kind=icon}
This video, screenshot or audio excerpt was originally uploaded on YouTube under a CC license.
Their website states: "YouTube allows users to mark their videos with a Creative Commons CC BY license."
To the uploader: You must provide a link (URL) to the original file and the authorship information if available.
This file is licensed under the Creative Commons Attribution 3.0 Unported license.
Attribution: Tyler Moore
- You are free:
- to share – to copy, distribute and transmit the work
- to remix – to adapt the work
- Under the following conditions:
- attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
|
This file, which was originally posted to YouTube: Gradient Echo (expand the description below for a detailed explanation)(archive), was reviewed on 14 February 2020 by the automatic software YouTubeReviewBot, which confirmed that this video was available there under the stated Creative Commons license on that date. This file should not be deleted if the license has changed in the meantime. The Creative Commons license is irrevocable.
The bot only checks for the license, human review is still required to check if the video is a derivative work, has freedom of panorama related issues and other copyright problems that might be present in the video. Visit licensing for more information. If you are a license reviewer, you can review this file by manually appending |
|
File history
Click on a date/time to view the file as it appeared at that time.
| Date/Time | Thumbnail | Dimensions | User | Comment | |
|---|---|---|---|---|---|
| current | 12:29, 19 June 2018 | 36 s, 256 × 240 (788 KB) | Vislupus (talk | contribs) | Imported media from https://www.youtube.com/watch?v=Rvpa1gqG06g |
You cannot overwrite this file.
File usage on Commons
The following page uses this file: