These diffusers, which can be bought at many different department stores, are highly porous. They allow the essential oils to diffuse first into the stone and then into the air. These can be placed or hung wherever they can be most useful, such as high traffic areas or in a doorway. People walking by will cause waves of air to move by the diffusers. You can also place these diffusers in front of a fan.  Once the oil evaporates, you will have to refill it. You can also buy necklaces specifically designed to do this as well, which are worn around the neck. Electric fan diffusers are available in a wide variety of sizes, shapes, and styles. These typically come with pads that are used to soak up the oils. The oils can evaporate quickly on these, but the pads are changeable. Avoid any diffuser that heats the oils unless there are settings on the diffuser that you can set to approximate body temperature. Nebulizers and atomizers are like humidifiers. They break up the oil into smaller droplets so they diffuse more easily. These usually contain two basic components, a base that contains the motor for the nebulizer and a glass or plastic bowl where the essential oil is placed.  Glass is preferable to plastic bowls because essential oils won’t stick to glass as much as they will to plastic. Be careful with the glass bowl, because they can be expensive to replace. There are a number of companies and businesses, both online and in stores, that sell these types of diffusers. See which type seems best to you, and check to see if there are any reviews or customer comments to find the best ones.

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Write a summary of the previous text in Vietnamese:
Dùng vật khuếch tán tinh dầu bằng đất nung hoặc đá sa thạch. Mua quạt điện khuếch tán hương thơm. Dùng máy phun khí dung hoặc máy phát tán không khí.