A43

src/lab/BackgroundPrinciple.html

@@ -108,16 +108,15 @@ <h1 class="text-h2-lightblue">Circular Dichroism</h1><div align="justify" class=
 <p>When the molecules in the medium are chiral (<a href="http://en.wikipedia.org/wiki/Chirality_(chemistry)" target="_blank">http://en.wikipedia.org/wiki/Chirality_(chemistry)</a>), then depending on whether the molecules are right handed or left handed, they affect individual interacting photons in different ways. These effects come under what are called chiroptical phenomena. Essentially, photons are associated with oscillating electric and magnetic fields, perpendicular to each other as well as to their direction of propagation. Since chiral molecules provide a chiral electrical environment they can affect the oscillating electric vectors, associated with interacting photons, in different ways. An ordinary beam of light consists of photons having their oscillating electric vectors uniformly distributed in all possible planes and, though the plane of the vectors associated with individual photons may change because of chiral interactions, the transmitted beam will still have a uniform distribution of the planes. So we can not track the chiroptical effects using ordinary light beams. </p>
 <br>
 <p><b>The phenomenon of polarization of light:</b></p><br>
-<p>However, if we use an optically anisotropic medium, such as a nicol prism, we can filter a beam of ordinary light so that the transmitted beam consists only of photons with associated electric vectors aligned to a particular plane. You are advised to go through the pages provided at the link <a href="http://www.enzim.hu/~szia/cddemo/edemo1.htm" target="_blank">http://www.enzim.hu/~szia/cddemo/edemo1.htm</a>, to understand electromagnetic waves and types of polarization. The following phenomena are explained in greater detail:</p>
+<p>However, if we use an optically anisotropic medium, such as a nicol prism, we can filter a beam of ordinary light so that the transmitted beam consists only of photons with associated electric vectors aligned to a particular plane.</p>
 <p><ul>
 <li>#Types of polarization (linear, circular)</li>
 <li>#Superposition of waves</li>
 <li>#Interference of waves</li>
 </ul></p><br>
 <p><b>Interaction of polarized light with matter:</b></p>
 <br>
-<p>We can detect chiroptical phenomena if we study the interaction of polarized light with matter. We know that interaction of light and matter leads to the phenomena of absorption and refraction. We have also seen above that any plane polarized light can be represented as a combination of two component linear polarized lights oriented horizontally and vertically, respectively, with respect to a reference plane. They can also be represented as a combination of two circularly polarized light components, namely right circularly polarized light (R-CPL) and left circularly polarized light (L-CPL). When plane polarized light travels through anisotropic materials, we can observe birefringence (differential refractive indices for the components respectively) and/or (usually both) dichroism (differential absorbance of the two components respectively). If the anisotropic material is chiral (optically active) then we observe differential refractive indices for R-CPL and L-CPL respectively, and results in a net rotation in the plane of polarization of the incident polarized light. In addition, we will also observe differential absorbance’s for R-CPL and L-CPL respectively, leading to an elliptical polarization of the emergent light, referred to as circular dichroism. These phenomena are nicely explained in the link <a href="http://www.enzim.hu/~szia/cddemo/edemo9.htm" target="_blank">http://www.enzim.hu/~szia/cddemo/edemo9.htm</a>. You are advised to go through the pages.</p>
-<br><p>Based on the principles discussed above, we have three spectroscopic methods for 'seeing' and 'counting' chiral molecules using polarized light</p>
+<p>We can detect chiroptical phenomena if we study the interaction of polarized light with matter. We know that interaction of light and matter leads to the phenomena of absorption and refraction. We have also seen above that any plane polarized light can be represented as a combination of two component linear polarized lights oriented horizontally and vertically, respectively, with respect to a reference plane. They can also be represented as a combination of two circularly polarized light components, namely right circularly polarized light (R-CPL) and left circularly polarized light (L-CPL). When plane polarized light travels through anisotropic materials, we can observe birefringence (differential refractive indices for the components respectively) and/or (usually both) dichroism (differential absorbance of the two components respectively). If the anisotropic material is chiral (optically active) then we observe differential refractive indices for R-CPL and L-CPL respectively, and results in a net rotation in the plane of polarization of the incident polarized light. In addition, we will also observe differential absorbance’s for R-CPL and L-CPL respectively, leading to an elliptical polarization of the emergent light, referred to as circular dichroism. These phenomena are nicely explained in the link</p>
 <p><b><u>Optical rotation</u>:</b> <br>
 This involves the measurement of the rotation of linearly polarized light by the sample.
 </br></p>

src/lab/exp6/Theory.html

@@ -131,8 +131,8 @@ <h1 class="text-h2-lightblue">To Study the effect of Secondary Structure element
 <img height="300" src="fig1.jpg" style="height:300px; width:400px" width="200">
 </img></td>
 </tr>
-</table><p>
-Structure of an amino acid<br> (source:<a href="http://www.bothbrainsandbeauty.com/page/3" target="_blank">http://www.bothbrainsandbeauty.com/page/3</a>)</br></p><br>
+</table>
+<br>
 <p>
 The variation among the amino acids occurs at the R group, which is different in each amino acid displaying different
 physiochemical properties (e.g. polarity, acidity, basicity, aromaticity, ability to from hydrogen bonds etc).