26 August, 2007
15 August, 2007
Indians - Believe in Yourself
As India continues to rise, the belief in Indians that they are nothing less is important. The dominance of the western world, western names in science and other fields may make a non-westerner start doubting his/her own abilities.
Any student of science/maths gets to hear about more and more western names given the credit for inventions/discoveries. Many voices have been raised by different people in India to claim otherwise on several fronts. But, these voices have not risen to enhance each other collectively but have been raised singularly.
Students of science/maths at 10+ level know about the importance of calculus. One can not imagine about learning Physics without being exposed to calculus. When one learns chapter on gravitation, one can occasionally read that calculus was invented by Newton and Leibniz. One can find the mention of the same names while learning calculus. The following is mentioned in page 319, new NCERT maths eBook for class 11th:
Here is a good news to cherish and to make us believe in our abilities:
Calculus Created in India 250 Years Before Newton: Study
The progress of a civilisation largely depends on the dreams of the people. Dreams are influenced by role models. It is important that the hidden real heroes are brought into the limelight. I hope that revelations like this invoke self-belief, inspire dreams leading towards achievement and contribution.
Any student of science/maths gets to hear about more and more western names given the credit for inventions/discoveries. Many voices have been raised by different people in India to claim otherwise on several fronts. But, these voices have not risen to enhance each other collectively but have been raised singularly.
Students of science/maths at 10+ level know about the importance of calculus. One can not imagine about learning Physics without being exposed to calculus. When one learns chapter on gravitation, one can occasionally read that calculus was invented by Newton and Leibniz. One can find the mention of the same names while learning calculus. The following is mentioned in page 319, new NCERT maths eBook for class 11th:
Here is a good news to cherish and to make us believe in our abilities:
Calculus Created in India 250 Years Before Newton: Study
The progress of a civilisation largely depends on the dreams of the people. Dreams are influenced by role models. It is important that the hidden real heroes are brought into the limelight. I hope that revelations like this invoke self-belief, inspire dreams leading towards achievement and contribution.
01 August, 2007
Determination Of Alcohol Content In Blood
Because blood passes through the arteries in the lungs, an equilibrium is established between the alcohol in one's blood and the alcohol in one's breath. So if the concentration of one is known, the concentration of the other can be estimated.
The test that law enforcement agencies use to approximate a person's blood alcohol level is based on the oxidation of breath ethanol by sodium dichromate. A sealed glass tube is used, which contains the oxidising agent impregnated onto an inert material. The ends of the tube are broken off. One end of the tube is attached to a mouthpiece and the other to a balloon-type bag. The person undergoing the test blows into the mouthpiece until the bag is filled with air.
Ethanol in the breath is oxidized as it passes through the column. When ethanol is oxidized, the red-orange oxidizing agent (Cr2O72-) is reduced to green chromic ion. The greater the concentration of alcohol in the breath, the farther the green colour spreads through the tube.
C2H5OH + Cr2O72-- --------> Cr+3 + CH3COOH
red-orange green
If the person fails this test — determined by the extent to which the green colour spreads through the tube — a more accurate Breathalyser test is administered. This test also depends on the oxidation of breath ethanol by sodium dichromate, but it provides more accurate results. Here, an accurate volume of breath is bubbled through an acidic solution of sodium dichromate. The concentration of chromic ion is measured precisely using a spectrophotometer.
Contributed by: Mr Devender Singh, dev_chem2002@yahoo.co.in .
The test that law enforcement agencies use to approximate a person's blood alcohol level is based on the oxidation of breath ethanol by sodium dichromate. A sealed glass tube is used, which contains the oxidising agent impregnated onto an inert material. The ends of the tube are broken off. One end of the tube is attached to a mouthpiece and the other to a balloon-type bag. The person undergoing the test blows into the mouthpiece until the bag is filled with air.
Ethanol in the breath is oxidized as it passes through the column. When ethanol is oxidized, the red-orange oxidizing agent (Cr2O72-) is reduced to green chromic ion. The greater the concentration of alcohol in the breath, the farther the green colour spreads through the tube.
C2H5OH + Cr2O72-- --------> Cr+3 + CH3COOH
red-orange green
If the person fails this test — determined by the extent to which the green colour spreads through the tube — a more accurate Breathalyser test is administered. This test also depends on the oxidation of breath ethanol by sodium dichromate, but it provides more accurate results. Here, an accurate volume of breath is bubbled through an acidic solution of sodium dichromate. The concentration of chromic ion is measured precisely using a spectrophotometer.
Contributed by: Mr Devender Singh, dev_chem2002@yahoo.co.in .
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