Rain drops....

Author Topic: Rain drops....  (Read 583 times)

Offline irina

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Rain drops....
« on: May 05, 2015, 04:36:11 PM »
Rain drops before hitting the ground have no smell but the moment they hit the ground and interact with dirt, the fresh and almost sweet fragrance comes out.

The smell is called "petrichor," that is derived from the Greek words "petra", meaning "stone", and "ichor", which refers to the fluid that flows like blood in the veins of the gods.

"They talked about oils emitted by plants, and certain chemicals from bacteria, that lead to this smell you get after rain following a long dry spell," said Cullen Buie, assistant professor of mechanical engineering at the Massachusetts Institute of Technology in Cambridge.

When a raindrop hits a porous surface it traps tiny pockets of air.

These bubbles speed upward before breaking the drop's surface and releasing microscopic particles, called aerosols, into the air.

Now, researchers think these aerosols carry the rainlike aroma.

The researchers observed the process with a system of high-speed cameras, reported LiveScience.

Depending on the speed of the droplet, and the properties of the soil, a cloud of hundreds of aerosol droplets might be dispersed in as little as a few microseconds.

The new research "brings the conversation of bubble-induced aerosol formation from the ocean over to the land," said James Bird, assistant professor of mechanical engineering at Boston University.

"This paper provides an elegant mechanism by which these microbes can be propelled past the stagnant layer of air around them to a place where the breeze can take them elsewhere," Bird concluded.

The findings were published in Nature Communications.

Offline Tahsina

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Re: Rain drops....
« Reply #1 on: May 06, 2015, 09:31:30 AM »
Dear Irina Madam, this is so interesting! From our childhood we have had this smell of 'shoda gondho' from the soil after rain. This has been researched by a group of people!! The explanation makes sense too. Thanks for sharing.
Tahsina Yasmin
Associate Professor
Department of English, DIU

Offline Shampa Iftakhar

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Re: Rain drops....
« Reply #2 on: May 06, 2015, 03:44:52 PM »
WOW!!! The title of your topic is really amusing!! Rain drops..

The rest of the article is worth reading and  interesting, too.

Offline Afroza Akhter Tina

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Re: Rain drops....
« Reply #3 on: May 12, 2015, 10:33:54 AM »
The topic along with the research result is truly worth reading ma'am!!! I agree with Shampa ma'am. Interesting!




Afroza Akhter Tina
Senior Lecturer,Dept.of English
Daffodil International University

Offline nujhat.eng

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Re: Rain drops....
« Reply #4 on: May 12, 2015, 01:55:03 PM »
wow just a pleasure reading this post
Nujhat Afrin
Senior Lecturer
Department of English