Overview
The earth's gravitational field produces a 'twisting force' perpendicular to the angular momentum of a spinning mass (such as a spinning top) that causes the mass to 'wobble' around the gravitational field axis in a phenomenon called precession. Similarly, the magnetic moment (μ) of a spinning nucleus precesses due to an external magnetic field directed along the z-axis. The precession of the magnetic moment vector about the magnetic field is called Larmor precession, and theangular frequency of precession (ω) is called the precessional or Larmor frequency, which is directly proportional to the applied magnetic field (B0). The proportionality constant is the gyromagnetic ratio (γ), which is fixed for each nucleus. This is because each nucleus has a unique ratio of magnetic moment to angular momentum on account of its charge and mass. For a hydrogen nucleus (a proton), the value of γ is 2.675 × 108 T−1 s−1. Expressing ω in terms of the operating frequency (ν) of the NMR instrument, rearranging the terms, and multiplying both sides of the equation by Planck's constant yields the relationship between the Larmor frequency and the energy difference between the spin states (ΔE).…
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Embed code vs URL
An embed code allows you to place a JoVE video directly inside of your learning or training environment. Most learning management systems such as Canvas, Blackboard, and Moodle require an embed code for JoVE content to stream.
A URL allows you to place a link in programs such as PowerPoint or Microsoft Word which takes a user to a separate page where they can watch a JoVE video.
Most of the time, you will want to use the embed code. However, there are some environments that don’t support embed codes such as Google Classrooms and MS Teams. In those instances, you can use a URL to still provide access to JoVE videos.
What is an Embed Code?
Basically, it’s a snippet of code that you put on your website that displays as a video. An embed code pulls the video from the original source, allowing you to display a video without having to host the file on your website.
How to embed a video
STEP 1: COPY YOUR EMBED CODE
To generate the embed code, simply click the Copy button above. You can customize it by choosing a specific language for the video, or setting exact dimensions for the video player.
STEP 2: PASTE THE EMBED CODE INTO YOUR ENVIRONMENT
Embed codes can be used in most learning management systems (Canvas, Blackboard, Moodle…), organizational websites, and a host of other tools. The specifics of how to add in an embed code will depend on your environment.
Generally, it involves accessing a text editor, entering the HTML mode on the editor, and pasting in the embed code. Get more details on embedding into specific environments here.