"Rail India"

Last couple of weeks I had roamed around a large part of India. I enjoyed Guru’s marriage in Trichy, presented a poster at MRSI-AGM in Lucknow. It was nice to go around few places within such short span of time. I was tempted to write about many things but thought about writing the strong impression I was carrying in mind for quite some time: Indian railways. Ram Guha in one of his famous talk series at CCS in IISc talked about how India as a country is in surviving, her binding and disintegrating forces working inside. One such binding force he mentioned is Indian Rail. The 150 yrs. old transport system has tremendous impact on the Indian society as a whole. One of the longest rail networks in the world is having maximum no. of stations too on her way. I would rather discuss about rail as a mode of conveyance than its commercial impacts. I frequently wonder, in practice what is similar in a life of a guy from Mangalore and one from Manipur. If he is not so cricket lover, which is not uncommon, he or she must identify themselves with railways systems. It is quite amazing how railways maintain similar system working in all corners of the country. The same bell rings with same frequency both in Guntur in AP and Tamna in West Bengal.
Indian rail began its journey in the year 1853 from Mumbai to Thane and within 10 yr. north, South east and West zone had rail tracks in different lengths. Today the total length of the railway track reaches upto 1.1 lakh km. Amazing isn’t it. We have broad gauge, meter gauge and narrow gauge tracks cumulatively making this length. Our rail runs from 20 meter under ground level to nearly 2500 m above mean sea level, which is the highest track after Quinghai- Tibet rail. Locomotives from electric to Disel and Steam can be seen running through track, though the steam locomotives are seen mostly out side the rail station now. Indian rail carries around 13 million people a day. Literally it is an unimaginable task; in order to ensure smooth functioning of this rail road system, Indian railways has become one of the largest recruiter in India. The employment is generated on national basis and people from all over the India travel from one corner to another.
Railway cities all over India have a very different culture as well as people. They are cosmopolitan in nature and the extent of cultural mix is quite significant. Whichever language you speak or whatever you eat, railway station is the safest place in the city (not always in terms of security). My trip from Chennai to Lucknow was quite an experience. Here I met one young couple who went for Honeymoon in Kanyakumar! That too from Lucknow, I asked him why Kanyakumari?, he said “..Because there is a direct train which takes us from Lucknow to Kanyakumari” Now here is a guy who probably would not have seen the tip of our country if there wasn’t this train. Like westerners we also develop some wrong notion about people of some places in our own country, just because we don’t know them haven’t seen them and didn’t know their culture, railways brought these cultures together more often than anybody. I came from Lucknow to Bhopal and from Bhopal I took Smapark kranti express to reach Bangalore. Here my fellow travelers were businessmen from Bangalore. One guy was from AP and another from Mangalore, they have business running from Delhi and both were mentioning how business prospects were different in north India compared to south India and they were pretty happy because of the prospects that were unfolded because of improvement in railway communication.
I was tempted to write more about it and one may find the write up pretty uninteresting since it doesn’t contain information. Well that because I found this group called Indian Railways Fan Club Association (IRFCA) who has already done a splendid job and their home page is really very informative, you can go and look at it, it is much interesting than this blog.
Cricket is almost a religion in India which brings all Indians on same platform, and we call our Indian cricket team as “team India”, probably for similar reason we can call Indian railways as “rail India”.

Few links

IRFCA

Indian Railways

light of life

This photo, was hiding in some corner in my PC. When i took it, didn't have much impact but now i could see the life inside the light :-)

Pass it through nanotube, it'll be quick

When I started working on ceramic membrane I was fascinated by the science. Especially working with the unsupported alumina membrane where you control the pore size at the nanometer level. Its quite tricky playing with these membranes. The problem is associated with filtering. It can filter out very small molecules easily but as the channels becomes smaller the wall friction affects the flow (Hagen-Poisullie equation), thus quite high pressure is required to pass the fluid through filter. Duration of the filtering process due to low fluid velocity also becomes extremely long; certainly from application point of view this is disadvantageous. There is a brighter side of the story! Recently my undergrad seniour, Mainak has published a paper in Nature couple of months back on carbon nanotube membranes, this paper addressed very similar problems. This group from University of Kentucky has made multi walled carbon nanotubes with graphite as the inner core; the average channel diameter is around 7 nm. When water is filtered through these membranes, the fluid velocity was observed to be few orders of magnitude higher compared to the theoretical prediction. The experiment was carried out on few other fluids and the results were very similar, they also observed that the flow rate does not decrease with velocity of the fluid, that’s really an interesting observation. The reason cited for this enhanced flow is the hydrophobic nature of graphite which makes the wall almost friction less to flow. There is also a possibility of forming ordered hydrogen bonds inside the tube. This behaviour is analogous to the biological cells where water passes through the protein wall at considerable pace. Following this claim carbon nanotube will have a huge application coming in, mostly as sensors and filters against corrosive gases. The important part of the question which I felt quite interesting is: if the conventional concept fluid flow in a tube breaks in case of MWCNT, will it hold for other systems? Does nano has any effect here? I f you remember I wrote something about nanomechanics by John Pethica, where he mentioned an increase in viscosity of water molecule when put between very thinly spaced walls. Although these distances are smaller compared to nanochannels, the flow rate must get affected when the pore size is reduced more. That technology is yet to come; we will probably witness subnano effects influencing flow.