"schlieren photography" meaning in English

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  "lang_code": "en",
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          "name": "Photography",
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        "Any of several techniques used to record regions of different refractive index in a fluid; especially used to visualize the flow of air around objects"
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        "schlieren photography"
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  "word": "schlieren photography"
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  "lang_code": "en",
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        "Any of several techniques used to record regions of different refractive index in a fluid; especially used to visualize the flow of air around objects"
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