urban plume 

城市尾羽层，也称城市尾烟气层，位于城市的下风向，这一层中的气流、污染物、云、雾、降水和气温等都受城市下垫面及边界层的影响 Located downwind of the city, the air flow in this layer, the pollutants, clouds, fog, precipitation and temperature are all affected urban surface and boundary layer.

Methane is further involved in selected chemical reactions in the urban plume relevant in photochemical smog.

urban plume by haosifeng January 20, 2015

Urban Plumber

The act of taking a nut connected to a bolt, putting it in your butt hole and then taking a wrench and twisting the nut around while the bolt is deep inside. This can be done on oneself, or two people can partake in the activity with one twisting the nut and the other enjoying it.

Me and my girlfriend tried the Urban Plumber for the first time last night, it was going great until she said it was my turn. So I pulled the bolt out of my ass and she put it in hers.

Urban Plumber by PullUpSkr July 18, 2016