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Benjamin Franklin/aide

Cours gratuits > Forum > Forum anglais: Questions sur l'anglais || En bas

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Benjamin Franklin/aide
Message de vincent11 posté le 10-11-2016 à 00:32:21 (S | E | F)
Bonjour tout le monde !
Je fais appel à votre expérience car je présente à des élèves anglais une histoire originale (accompagnée d'un powerpoint) : l'histoire de Benjamin Franklin et la tache d'huile. Le fait est que je me suis appliqué au maximum pour éviter les fautes d'orthographe et de grammaire. Cependant ma piètre confiance en moi vis-à-vis de l'anglais me pousse à demander relecture. De plus, il y a une phrase que j'arrive très bien à formuler en anglais mais que je n'arrive pas à traduire : "Je vous laisse vous poser la question :"Où en serait la médecine si on avait su, 128 ans plus tôt, comment fonctionne une cellule ?"
Le texte est ci-dessous, l'histoire est intéressante ! Je vous suis d'avance très reconnaissant de votre relecture

"The cell membrane
As you know, the cell membrane is mainly composed of lipid.

But this fundamental discovery was possible thanks to many scientific:
• Robert Hooke observed that for the first time a cell through a microscope.
• Antonie van Leeuwenhoek observed for the first time protozoa, bacteria and red blood cells.
• Ernest Charles Overton discovered that the ability of a substance to pass through the membrane depends on its hydrophobicity. He understood that the membrane was composed of lipids.
• Lord Raleigh calculated the thickness of one molecule and more precisely of an oil film on the surface of a body of water.

And now the question is to know : how Benjamin Franklin could have calculated the thickness of a molecule but 128 years before Lord Raleigh.

Who’s Benjamin Franklin ?
You probably know Benjamin Franklin
• for his work on the independence of the USA,
• for his face on hundred dollar bills,
• or for his famous experience of the kite (=cerf-volant) where he proved the electrical nature of lightning.

But Benjamin Franklin is also a great inventor with some of his inventions like
• the lightning rod,
• the glass harmonica,
• the franklin stove
• or glasses bifocals.

The Franklin’s experience
In 1762, Benjamin Franklin went to the lake Clapham. He pours the equivalent of one teaspoon of oil on water (2cm3). He returned the next day. He finds that his oil spill was spread over more than 2000 square meter. He did not try to go further.

The Rayleigh’s experience
128 years later, Lord Rayleigh, poured a little oil in her bathtub. And discovered the size of a molecule.

What Benjamin should have done ?
First of all, he should be curious and ask himself : how is it possible ?
Secondly he should ask himself : how does it work ?
And last but not least , he should understand that if the oil stop increasing size, there is a reason.

He knows the volume (2cm3) of the oil in the teaspoon, he knows the size of the oil on the water (2000 m2) so he could found the thickness of the oil.

Volume = surface area * thickness
So Thickness = Volume/Surface Area = 2*10-3/2*106=2*10-9
And that exactly what Rayleigh did in his bathtub

How does it work ?
A lipid has a hydrophilic head and a hydrophobic tail. To be as stable as possible, lipids orient their head to the water, and tails to the air.
So, all molecules are oriented in the same direction and extend over a large area.

The same phenomenon takes place in the cell membrane"

Par avance merci mille fois de votre sollicitude !
Cordialement.
Vincent.

-------------------
Modifié par lucile83 le 10-11-2016 08:14


Réponse : Benjamin Franklin/aide de here4u, postée le 11-11-2016 à 12:10:54 (S | E)
Hello !
la forme de "plan" est un peu ambiguë à cause de l'ordre des mots ... Il faudra décider si les questions sont posées à la forme directe, ou indirecte, ce qui change beaucoup!

"The cell membrane
As you know, the cell membrane is mainly composed of lipidS.

But this fundamental discovery was possible thanks to many scientific:(nous voulons un nom!)
• Robert Hooke observed (that for the first time a cell = ordre des mots.) through a microscope.
• Antonie van Leeuwenhoek observed for the first time= = en fin de phrase= ne pas séparer un V de son COD!) protozoa, bacteria and red blood cells.
• Ernest Charles Overton discovered that the ability of a substance to pass through the membrane depends on its hydrophobicity. He understood that the membrane was composed of lipids.
• Lord Raleigh calculated the thickness of one molecule and more precisely of an oil film on the surface of a body of water.

And now the question is to know : how Benjamin Franklin could = ordre des mots dans une question? )have calculated= temps!) the thickness of a molecule but 128 years before Lord Raleigh.?(est-ce une interrogative directe ou indirecte?)

Who’s Benjamin Franklin ?
You probably know Benjamin Franklin
• for his work on the independence of the USA,
• for his face on hundred dollar bills, (lucky ones if they've seen so many! = très difficile de se faire accepter des "grosses coupures aux US!)
• or for his famous experience= vocabulaire) of the kite (=cerf-volant) where he proved the electrical nature of lightning.(construction? )

But Benjamin Franklin is also a great inventor with some of his inventions= very clumsy!) like
• the lightning rod,
• the glass harmonica,
the franklin stove ( Lien internet

• or glasses bifocals.( Lien internet
=
The Franklin’s experience
In 1762, Benjamin Franklin went to the lake Clapham. He pours the equivalent of one teaspoon of oil on water (2cm3). He returned the next day. He finds that his oil spill was spread over more than 2000 square meter. He did not try to go further.

The Rayleigh’s experience
128 years later, Lord Rayleigh, poured a little oil in her bathtub. And discovered the size of a molecule.

What Benjamin should have done ?(once again, is it a direct or an indirect question?= word order? )
First of all, he should be curious and ask himself : how is it possible ?
Secondly he should ask himself : how does it work ?
And last but not least , he should understand that if the oil stop increasing size,= clumsy ...) there is a reason.revoir la construction.

He knows the volume(2cm3)of the oil in the teaspoon, he knows the size of the oil on the water (2000 m2) so he could found the thickness of the oil.

Volume = surface area * thickness
So Thickness = Volume/Surface Area = 2*10-3/2*106=2*10-9
And that Verb? / Auxiliary? exactly what Rayleigh did in his bathtub

How does it work ?
A lipid has a hydrophilic head and a hydrophobic tail. To be as stable as possible, lipids orient their headS to the water, and tails to the air.
So, all molecules are oriented in the same direction and extend over a large area.

The same phenomenon takes place in the cell membrane"

You're welcome, Vincent! Good luck!

-------------------
Modifié par webmaster le 11-11-2016 12:35



Réponse : Benjamin Franklin/aide de vincent11, postée le 13-11-2016 à 20:42:47 (S | E)
Merci infiniment pour votre aide !




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