Carrying a full cup of coffee from the kitchen to the dining room can be precarious1 for a sleepy-eyed caffeine addict2 who might accidentally send a wave of java sloshing over the rim3. But add a bit of foam4 to the TOP and the trip becomes easier. Scientists have found that just a few layers of bubbles can significantly dampen the sloshing motion of liquid. The research, reported in the journal Physics of Fluids, from 人工智能P Publishing, may have applications far beyond breakfast beverages6, including the safer transport of liquefied gas in trucks and propellants in rocket engines.Emilie Dressaire, now an assistant professor of mechanical and aerospace7 engineering at the New York University Polytechnic8 School of Engineering, remembers first thinking about foam as a damping mechanism9 when she was handed a latte at Starbucks and told she probably would not need a sTOPper to keep it from spilling. When Dressaire began working in the complex fluids group at Princeton University, she learned that her colleagues had noticed a similar phenomenon with a different foamy10 beverage5: beer.While I was studying for my Ph.D. in the south of France, we were in a pub, and we noticed that when we were carrying a pint11 of Guinness, which is a very foamy beer, the sloshing almost didnt happen at all, said Alban Sauret, who is currently a researcher at the French National Center for Scientific Research .The scientists took their observations from the coffeehouse and the pub to the laboratory, where they built an apparatus12 to test the damping power of foam more systematically13. They constructed a narrow rectangular container made of glass, which they filled with a solution of water, glycerol and the commercial dishwashing detergent14 Dawn. By injecting air at a constant flow rate through a needle located at the bottom of the rectangular cell, the team created uniform layers of 3-millimeter-diameter bubbles. The dishwashing foam is very stable, which allowed us to conduct the experiments without the bubbles disappearing, said Franois Boulogne, another member of the team.
点击收听单词发音
1 precarious adj.不安定的，靠不住的；依据不足的 参考例句： Our financial situation had become precarious.大家的财务情况已变得不稳定了。 He earned a precarious living as an artist.作为一个艺术家，他过得是朝不保夕的生活。
相关文章推荐
