Friday, December 30, 2005

Candle lit vigil

Today the students in the campus have decided to have a candle lit vigil in front of the main building. It is a geture we carry out to pay homage to the souls who are no longer around us and for spreading the message of peace. It was a very peaceful gathering of 150 students. The director, prof. Balram was as usual very inspiring but appeared really weary, of course because of the unusual circumstances he faced. We condoled the sudden demise of Prof. Puri, and hoped for a faster recovery of those who are recovering in the hospital. After the vigil we had put the candles at the steps wher J. N. Tata is standing tall. The glowing light carried a promise to walk ahead and and remeber the Prof. Puri. At the end the gathering was asked to speak a few words but the silence was talking; We all despised this heinous act.

Thursday, December 29, 2005

Attack inside IISc !!!?

This is the same J. N. Tata Auditorium where the peace ambassador Desmond Tutu talked about peace in this part of the world. This is the place where we saw “Keepers of the flame”, the life documentary on Tatas and we were shown future path of our country, and yesterday we encountered the path which we are traveling through. Few cowards with automatic Kalashnikov has fired indiscriminately on delegates of an international conference in front of J. N. Tata auditorium. When I heard the shooting sound from the lab it was like firecrackers which lasted for 30 sec. In my worst nightmare i haven’t seen such act. Though jolted by the news, frantic calls and ambulances really perturbed the campus, life became normal in the night It was really shocking, we all mourned at the demise of prof. M. C. Puri, and we wish a fast recovery of the others injured in the shootout. Prof. Vijay chandru is a quite known figure in the campus and we hope he’ll be back on his feet very soon.
Inside the campus we always get bugged when a byke’s accelerator crosses some limit, no doubt this incident perturbed the campus but within one and half hours only TV channels were busy discussing it, most of the student had gone back to work. It’s a busy life in the campus; the spirit always carries through day and night in silence. It a shame on the guys who attacked un-armed delegates and researchers. I don’t know their purpose, whatever it is we believe there is no novel cause which can justify such acts. If they have strong will they should come forward and fight not with arms, it is cowardly and if they had thought they will hit a weak zone, certainly they have chosen the wrong place. They should come to the campus and see that nothing has changed except some physical marks they left here yesterday evening. I don’t know whether this/these guy(s) will be caught or not, but it is sure, in India we have learnt to live with it. So if someone wants to create an impact, they better find some new tricks!

Saturday, December 24, 2005

The big controversy in cricket

Probably the biggest controversy in the recent times in cricket has hit the media. Nup! not Saurav or Greig, its with the greatest spinner Murlitharan and Shane Warne. After the controversial stament by Shane where he indiacted to a famous bowler (presumably Murli) in the world cricket captured lot of wicktes playing against minnows like bangladesh an Zimbabwe. Well Arjuna Ranatunga the fighter fought back saying that Shane's most of the wicketes came from the teams like South Africa and England and Westindies, who doesn't play spin well, not against India the masters against spin (thank god they didn;t forget it). Most of his wickets came as tail enderes and he is an overrated bowler. i am sure there going to be huge discussions about it statistics has been already popping up, but seeing the statistics i was wondering both the partys should keep quite if their performence is kept agains Kapils performence, who never played against Zimbabwe or bangladesh, and he was a Fast bowler from India! if we take out 150 wickets from both of these bowlers, Statistics from Kapils career would look certainly brighter. May be they should stop at this because both of these spinners are really greats and their bowling it is always a treat to watch, perhaps its a time they along with their friends keep quite because we can put Kapil ahead of them :D

Friday, December 23, 2005

nanomechanics and Prof. John Pethica

Mechanics although sounds mechanical but its starts from the chemistry of atoms and you have mechanics when two atoms comes close to each other. This is how Prof. John Pethica looked at mechanics. Prof. Pethica is a big name in the field of contact mechanics and became quite popular in the campus. His cv is all over the web and I don’t want to write it here.
When two bodies come close to each other there are attractions and repulsion which act on them, and probably this is the first time I saw somebody really, experimentally showing the typical energy plot that we find in all basic material science book Prof Pethica and his group has done it using AFM. He explained the mechanism which drives an atomic force microscope to read the atoms. The striking technology is in the resolution. A laser goes through the tip and reflects back and by detecting the multiple reflections that is coming back, through which it was possible to achieve atomic level resolution in AFM. The probe for AFM can be used as a tool for striking the antom and calculating bond strength between the atoms. So you can literally feel the chemistry of the atoms. It’s really fascinating. So Prof. Pethica’s group in Dublin is working with some technique, developed most probably by them, which is called modulated amplitude AFM technique, this is very effective in measuring the single tip surface bond, the mechanism is bit complicated but it has responses coming in femto seconds and there are advantages over the other tips used for this purpose. After mesmerizing the audience with his measurements in the atomic scale he shifted to some interesting studies on molecules. No, it’s not the big organic molecule, it is water molecule. When the water molecules are kept in between two plates with sufficiently closer (less than nanometer) you start seeing some changes such as viscosity and those change are because of the contacts between the water molecule and the surface. It’s an interesting study from the point of view of biologist as inside a cell the length scale in which water molecules sits is almost similar in order. Prof. Pethica, at the end of his lecture showed few slides of the nano science building at the heart of the town in Dublin. He really wanted to convey the importance of the nano science and technology, but I had a feeling that he has reached beyond that!

Saturday, December 17, 2005

Space Research

Discovery of vacuum was a revolution, its helping someway or other the poor souls like ours, but life moves on. Once we have vacuum we can do lots of model experiments, that will gives us a clue of what can happen in the space above us, but, hold on, you can not get rid of the gravity so easily until you cross the field and go in to space. The amount of effort that goes in behind the space research is huge but now research in space invoked a great deal of interests among the researchers. Presently NASA and ESA has carried out quite a few experiments in space and believe me they are really fascinating.
Experiments in space were started probably through sputnik-3 in 1969, which sent mostly some geophysical information. Until very recently, experiments were concentrated mostly on the atmospheric or geophysical studies but the scenario has changed quite rapidly. Experimental research had leap when Mir was placed in space in the year 1986, and from year 1989 till it was abandoned in 1999, there was always a human being in space. The Venture, International Space Station, took the lead there after. Scientists from all over the world including Russia are participating in this program.
The idea of carrying out experiments in a space station appears bizarre to many people, mostly because of the cost and the futuristic nature as we can not see the application. The fact is someway different; these experiments are mostly carried out for advanced technology. I found one nice example; an experiment on flame. The flames coming out of some nozzle appears like a fluid drop due to the gravitational force resulting in an air flow. Now if these experiments are carried out in space under microgravity atmosphere the flame breaks in to balls, the experiment is known as Lwis SOFTBALL experiments. For this combustion the fuel required is extremely low, which is a process all automotive engine companies will look for, as the hydrogen or hydrocarbon based combustion engines requires these informations. This was an example for a direct application to technology. However, the fundamentals for the basic science are getting major benefits from the zero gravity experiments. Imagine a human brain, which has been modeled to function under gravity, when it is exposed to the microgravity condition, the systems response to this change. It is therefore an interesting area for study. Again we know the plants grows in the direction of light, its roots also grows in the direction of gravitational force, hence it is interesting to know how the plants grow in such conditions.
Materials research did achieve much scope to carry out experiment although levitation experiments for solidification of metals have drawn interest. The constraints are mostly forming the experimental module and control over the experiments, the results is unknown till the specimens come back to earth. Among the other materials research semiconductor crystal growth has been quite a revelation. Near perfect crystals can be grown under microgravity, under surface tension driven flow in the melt. A control in the defect concentration in the crystal is also possible, but its is not so straight forward as the density driven flow and surface tension driven flow complicates the process. The container free melt will have hardly a site for defect nucleation hence these processes are really useful.
Every scientific advance comes with a price tag and we had to pay it through the lives of astronauts who were killed the Columbia explosions. These were the part of NASA’s STS -107 program, more than 70 experiments were carried out in space. We have lost Kalpana Chawla, the only Indian female astronaut.
Efforts are on as many other countries are coming up with ideas and launch vehicles for carrying out experiments. Indian space research also as an individual progressed a lot and one day we will also be able to carry out our own experiments in space.

I found infornation from the following places

Future Materials Science Research on the International Space Station (1997), National Academy publishers

NASA

European Space Agency

Russian spaceweb

News about ISRO

Tuesday, December 13, 2005

spread your wings and fly eagle.. Desmond Tutu

The notice on a pink colour A4 paper remained un-noticed in the campus, and it gave some of us an opportunity to listen to Desmond Tutu the Nobel Peace prize winner for the year 1984. I miss most of the Nobel laureate lecture in the Institute because I reach late and the halls will be completely filled, this time it was in J. N. Tata auditorium and because of mentioned reason I could hear this piece of lecture. The presence of sniffer dog/bitches from the police near the stage gave really a wrong introduction to right event.
The speaker of the 7th and the last J.R.D Tata memorial lecture, organized by NIAS was Arch Bishop Desmond Tutu from South Africa. He was really humble at the beginning of the talk. He spent almost 10 min. in thanking us, the Indians. I rarely hear someone talking about Mahatma Gandhi with such emotions. If I am hurting someone, then let me confess I heard very few of them. He sounded more like a Global Spokesman of peace than an arch bishop from Capetown, who fought apartheid and the man behind the reconciliation mission. Of course, South Africa has moved ahead from the apartheid era, but still I wonder how this reconciliation is done; atrocity must be at a level where punishment is the solution. His talk was a reminder of the last century’s blood bath all over the world, and the born of so called super powers who carried that legacy to the next century in the name of west vs. Islamic terrorism. He criticized the America and Britain for their unwanted and unnecessary invasion in Iraq where thousands of people were still getting killed. If the description of the talk is becoming serious then let me put down that he also had a humorous touch in his talk and he mixed them really well. He described the incidents, one about the women who came to the reconciliation court and was requested for forgiveness, and the other of the hotel manager in Washington who mistook him as a chauffer, with equal intensity! There were parts of the lecture where he talked about the oppression, quite depressing but when I read his Nobel lecture, I found he actually didn’t talk about oppression much. Surely, he followed his talk titled “is there hope for humanity?”. Arch Bishop Tutu, is in a UN committee called alliance of civilization and he is carrying out the job for getting together the civilizations around the world, according to him, we can prosper only when we are together. Human being lives in the world of Gandhi, Mother Teresa, and Martin Luthar King (junior), and they are like eagles that fly towards the rising sun and disappears. It was a quite unusual lecture for us but hats off to the man from Capetown!

Few links!

His Nobel lecture

His peace centre

Friday, December 09, 2005

memory under freeze

...Saswata has kept a hard disk inside a freeze to retrive data from it :D, First time i had laughed like this. Although he is famous for humourus activities but this time i was fooled as i found people have found it as a good technique for retriveing data from the "failed" hard disk. So just take the HD and keep it inside a freeze for couple of hr. and fix it back, if you are lucky then you'll get your data back. Sounds like a cool trick. May be Semiconductor guys can put some light on it, and from materials scienctist point of view its really interesting.

You want to succeed ?

You want to succeed? You need to be a good leader; you have to learn how to “manage” people. We hear these line so many times from our childhood that at some point it really becomes a fact. There is nothing which is absolute, from my childhood this is the one thing I have learnt. If you say when, well there is always plus and minus. If you say this is the end, then there is nothing call end, an end marks a beginning. I used to wonder and now always feel something that eludes me is an understanding of these facts. I always knew if I buy a chocolate I have to give the price the shopkeeper asked, but never realized why there was a bargain when I wanted to buy a T-shirt. I can not remember how many times I was directly and indirectly told that there is no fixed price for something, we can always “adjust”, this is an understanding and a balance. Then comes the big institutes, if you see the instructions booklet, you as a student will find the class room as the safest place on earth and if your actions are put under microscope you will break numerous rules each day, if you think they are strict rules then you always live under guilt, but there are guys, who know there is no rule, you can break them to any extent and get away with it, of course if you are a good “manager”. There is a third way become indifferent about the happenings around you. Once my friend Pratap in an argument pointed out that if one always go straight without any diversions, then all lives will be parallel, no interaction and hence no society, its the society who kept you alive not the individual. He has a point and any discussion in this matter boils down to one fact, small adjustments which don’t make much difference are ok, after all you are in a society. So take help from individuals don’t even bother to thank him, because you are going to return it to the society, the return need not be in the same magnitude as nobody can compare potato and apple. Everyone adjusts, compromises; human beings are small creatures even the earth has compromised her shape, its not completely spherical, sphere has been slightly tapered at the poles: a small adjustment but enough to keep us alive, but I am rigid M who will never understand this simple logic.
It’s a pleasure of not being argued in the middle of cribbing so that I could put down quite a few lines of my own here. Disclaimer: this post is not pointing towards any individual or organization :)

Sunday, December 04, 2005

Cricketing memories

.....Its a quite old event, i mean its 3 months old event, before i broke my finger and before we faced all kind of problems. This was our first match in league and we won it as we had won the last one. These are the big stars of IISc cricket team, and the small stars are at the bottom. partha got 6 wickets and I scored 75 in that match. Most of the team performed in similar fashion in other matches but unfortunately Sandeep's camera couldn't catch them. Kapil the caps is not here. ViveK, Mahesh are also missing.




Srini, Sachin, Partha, Atul, Kumar, Venu (star faculty), Jackie (Santanu)
Sandeep, Uncle (Surinder), OP, Saru(Sarendra) and me




Me and Partha

Friday, December 02, 2005

in CHENNAI for NMD

I feel sometimes myself like the Shepard in Alchemist. Though I don’t dream about pyramids, but I always grab opportunities to visit places whenever possible. This time it was Chennai, and NMD-ATM, annual technical meeting of metallurgist from all over India. Along with the meeting I actually wanted to visit IIT-Chennai. So now I have seen two IITs. ATM followed FDM, the international conference on future of materials where Atul presented a paper, and I was fortunate enough that he had put my name in it! Thanks Atul! Before ATM I have to mention NMD because on that day Dr. Phanikumar got the young metallurgist award and I want to congratulate him.
I heard before the conference that ATM is a low profile conference, but was elated to find that a portion of the talks were really good. The participation was really huge, posters as well as speeches. A whole gamut from materials and metallurgical research came here. Truly speaking conference was very general and I had to find talks of my own interest. There were three parallel sessions. I was especially interested in the mechanical behaviour of materials, some functional stuffs and then Ceramics of course. I had attended few sessions on mechanical behaviour of materials. First day, 15th Nov. I found some interesting stuffs about Spark Plasma Sintering processes. ARCI is currently doing lots of work on that, with Dibyendu around I would also try something! Guru’s rafting was as usual good and I guess serendipity is knocking his door. There was a talk by Vendervort, the king of metallography and also days end Vikram mesmiriesed audience with a 10 min talk on wear. Second day it was bit hectic, as I wanted to attend the talk on metallic glasses, it was interesting session, Krishanu presented his paper on non-equilibrium solidifation which was good, better was his answers ( Dr. Dey, from BARC showed some beautiful HREM micrograph of the metallic glasses, again the controversy begun whether there is crystallization at the shear bands, Prof Ramchandra Rao, pioneer in the field was also present there. Rejin, hurried through his beautiful talk! Just for attending Vikram’s lecture, but his experiments for exhibiting Ductile Brittle transition was really good. Vikram was fascinating in his talk on the amorphous ceramics. Its really a magic material only requires good magicians like prof. Jayaram.It was more like our class room, but I wasn’t happy with the explanation he tried to give in support to the densification at high temperatures. The nano grains grow so fast, it is really difficult to differentiate between densification, creep and grain growth processes. I would be unfair If I miss the last talk which a girl from IGCAR delivered. They were using Infrared camera for strain measurement during tensile experiment. Not only the local strain it was possible to measure the stress distribution in the specimen, for large component which may be a good tool to use, but what I understood is that there are limitations in the shape of the resolution of the camera.
Its like writing a summary of Ramyana, I would have loved to describe each of the talks I participated but that’s some other time. What I really want is to thank all the faculty staffs and students, from IIT Chennai, life were really tough for them in that last week.

home "together"

I was standing at the door of the compartment, while the train was slowly crossing the bridge over Krishna. Sky was full of clouds rain drops were piercing through my skin; I was really enjoying it as I was going home. It was dusk and Krishna looked beautiful, with water reaching from one corner to the other and the river met the horizon. I was standing at the door because my seat was occupied by some students from Ramaiya College; I tried to raise my voice but gave in to the teens. I didn’t sleep well in the night, not only because of the extravagant students but also for the unusual bed, but I didn’t complain, as I was going home. Early morning I woke up and the first thing that I heard was that the train is running late by 6 hr. Bad times were still sticking with me! The whole day my walkman was really helpful, the girls and the guys were enjoying a lot and making plans for diwali I found myself an odd man out, realized that I have crossed some stage of my life, but I was happy like others: we were all going home. That whole day I finished a book which “kotts” gave me mentioning that as a mediocre book, “interpreter of maladies” by Jhumpa Lahiri, it’s a collection of short stories and except the name story, I found most of the others quite good. Then came the last night in train, by the time it was running 8 hr. late. I remember one girl was traveling to Patna and she was going to miss her train from Howrah, it was such a helpless situation for her and her family that, her father started travlelling from Patna to Howrah to take he daughter along with him, it didn’t bother me much you know; I was reaching home! Finally the train reached Kharagpur, after a delay of 11 hr. It was a bright sunny day, finally a bright day, I don’t after how many days I was enjoying a bright day. Last four months it really poured heavily in Bangalore. My big bro rented a car and came to pick me, it was a nice time. My house is at a beautiful place called Jhargram, of course to me. This place is just 7 Km. away from my home.



photo courtsey: My bro Debraj

I was really feeling great; Not only “dada”, Chiku also came along with him, we had a ball of a time in the car, and then after 47 hr. after leaving the lab finally I was at this place…


From bro's cell:appears bluish in reality not so much

No prize for guessing, yes! So I was at home !

After the break


I had compre and then I went home, and then I had to start working, where is the time for blogging :D. Along with this fact there is truth and the truth is I was lethargic, but came back powerful.

Tuesday, October 11, 2005

thanks Stuts!

...i know u'll no c this! but this the only way probably i can thank you :). I finished my compre today.

Tuesday, October 04, 2005

grain size refinement in the nano range

The title sounds too technical, but it will go this way as my compre is nearing and I am reading up few things which I thought would put down.
In the end of 20th century people could easily achieve grain sizes in the sub-micron range (<1 micron) in zirconia ceramics, but it wasn't sufficient; there was a strong driving force to refine the grain size to nano range (< 100 nm) of course for obtaining certain advantages, mostly enhanced structural and physical properties. Beginning of this century observed a difference in mechanical behaviour in nano-grained tetragonal zirconia from the sub ┬Ám grained one. This drove scientist to study this mechanical behaviour of nano zirconia whether it is tetragonal or monoclinic. Now the problem associated with density. It was not so difficult to achieve a grain size which is in nm range but with a density as high as 99% of the theoretical density, it was difficult. Currently there are few techniques which satisfies both requirements. Spark plasma sintering (SPS), Microwave sintering, Sinter-forging, HIPing, also the brand new one is crystallization from glass!In the first two processes control grain size is very limited and the sintering mechanism is still not completely understood. In SPS there is a huge current of the order of 1 kA and more is passed through a powder compact and it claimed to form plasma which sinters the material to full density very fast with a very small grain size, but with very little control. In the microwave process, both electric and magnetic field interact with the material, and the absorbed energy actually leads to very fast sintering, again microwave, though, is in industries now, and still is feeding significant no. of researchers around the world. This leaves us with Sinter-forging, an excellent processing technique which was first opted by couple of groups, Rehemans’ and Raj’s, in mid 80s. At high temperatures without any wall constraint if a compact under load is sintered, the sintering rate is enhanced by couple of factors; one is the stress induced diffusion becoming faster and disappearance of big pores by plastic deformation. In zirconia it was observed that instead of the applied stress actually the plastic strain controls the densification. Now here the advantage is that, one can independently play around with two parameters; stress and temperature and you can achieve grain size really in the nano range in a fully dense material. The pictures below are from sinter-forging experiments. One needs to monitor the transverse strain also along with the axial strain and in these experiments, for this specific experiment I used a digital camera in my I.I.Sc lab. These images were taken at 1423 K. Extreme right one is from the final stage of sinter-forging. You may notice that there is very little strain in the transverse direction compared to the axial direction, which indicates densification. I did not put the scale which is a “crime” but take it from me; the height of the specimen is 3.5 mm.



So now we have a nano-grained material, but what is the size? It is difficult to push the grain size of the bulk dense body below 50 nm, this is one shortcoming of sinter-forging. So here comes glass. The idea is like this: you take these oxides to very high temperature and cool it with a cooling rate of the order of 103 to 104 K/min and they may form glass or some amorphous phase, and now if this glass is taken above the transition temperature, the crystallite starts nucleating and the body becomes a dense nanocrsystalline body with a crystallite size may be as low as 15 nm. This processing technique is difficult and there are critical issues involved with density, still it gives you the grain size you want. What else, if I have such material (from 15 -100 nm) in hand, a through mechanical property study is possible. Then I know serendipity will knock my door any day and I will jump and shout…………:D

Saturday, September 24, 2005

Watch out, its coming.....

Costal areas all over the world are prone to attack. Most of the time the attack comes from the sea and in the form of storms. Whether it is India or America, they natural destruction stories remain the same. These monster attackers are named differently all over the world in America it is called Hurricane, in Japan and China it is called Typhoon, In south and south east Asia it is called cyclone. However, all of them form following a similar mechanism. Warm air flowing over the sea suck water as vapour, because the temperature of the air would be as high as 80 oC, these water vapour cools down at higher altitude and releases heat which results in more heated air which is light, this air gains a speed of 200 miles per hour and due to earth rotation the air starts whirling around an eye, this is how it looks.

Red part of the hurricane contains water. These tropical cyclones travels 300-500 km a day,
they loses strength but very slowly and before it tames it hits the costal life. This monster has three weapons. First is of course storm, which hits at a speed of 200 km/hr. it is followed by heavy downpour, much more than that of any low pressure cloud pouring. It has got a disguise also. Once the eye crosses the land the rain and storm stops, it is an warning which people often misses, the storm comes from the opposite direction. It is huge and deadly. The devastation has just started. Almost 90% of the casualties come from the surge of water, the third weapon of hurricane. The sea levels go up by 10 to 30 ft. and in extreme cases it reaches 40 ft.! The surge of water we saw in New Orleans is actually due to this. The storm carries through the coast and may travel till 1000 miles! Slowly loses its pace and die down. The devastation is always quite tragic. It affects the flora and fauna immensely. Moreover, geophysical changes are also come along with them. Discovery.com has posted some before and after Katrina photograph in their web page.
Typhoons and Hurricanes are normally named, although “Katrina” rocked USA, it is not the deadliest ones world has witnessed till now. In India in the year 1999 there was a cyclone hit. Actually there was couple of cyclones that hit costal Orissa. First one hit Andhra Pradesh, Orissa and West Bengal and the second one without warning hit Orissa and India saw the one of the worst cyclone hit. The Cyclone lasted for 2 days and whole state was out of the world. It was said the wind speed reached 310 km/hr with an water surge of 20-30 ft. It completely destroyed the state; there was no account of the death toll as well as the homeless. A huge part of the coast beacame a barren land, with all the trees uprooted. The economy and life was affected such a way that still people are recovering from it.
Science has progressed so much that following the Hurricane is possible from its birth hence it is possible to do the necessary evacuation. Computer simulations following the satellite imaging have done a real miracle, but researches are on in this topic. One big topic is the effect of pollution like global warming in the frequency of the storm. Recently there was an article on hurricane on a work by a group from university of Tennessee in Knoxville. They are studying the Pine trees in coastal US and it was claimed that these trees bear signs of Hurricane, so the frequency of it can be identified at least for last 100 years! We don’t know whether these are signals of destructions that are coming or passing by!

Hurricane
Orissa Cyclone
Hurricane mark in Pine trees.

Thursday, September 22, 2005

Segregation

If you search segregation in google, first few hits will be about racial segregation; strictly speaking I am not going to talk about it. It’s the segregation in materials world is my cup of tea. While working with oxide ceramics defects are something that never left me and now I say I love defects! There are classic effects you get to see due to presence of point and line defects in the materials, whether its semiconductor or any structural applications. Segregation is a results caused by point defects. It has been exploited in many ways. Optoelectronic, Transistor, structural ceramics, there are numerous occasions when segregation is the key. In the ionic solids, the Schottky defects causes ions to go to the interfaces, primarily they require a lattice discontinuity, so this place may be a surface, a grain boundary or any interface. Thus there is a local charge builds up there and a potential difference between the bulk and the surface is generated. The magnitude depends on the defect concentration, temperature. Like colloids there exists an isoelectric point where surface charge becomes zero and then with an increase in temperature or defect concentration it reverses. Segregation is a subject of interest of the structural community as this process retards grain growth. The space charge which forms at the boundary actually pins the grain boundary mobility. Sounds interesting? It has more effects; when you reduce the grain size that is in the nanometer range lot of material properties in oxide ceramics is controlled by segregation, hope you didn’t believe it! Segregation captures a huge part in grain boundary engineering. Si3N4 brittle in nature but it is toughened by adding some dopants, but how it helps was not known till very recently. Last year a paper in nature showed experimentally evidences of La segregation in La doped Si3N4, La actually segregates to the boundary and helps in forming elongated grains which in turn toughens the material. Following figure is actually taken from the paper.



N. Shibata et al. Nature Vol. 428, pp730-33, 2004.

This is an STEM micrograph of a grain boundary in La doped Si3N4, bright fringe in the middle correspond to the amorphous film and the brighter spots in that are actually La. Segregation in YTZ is in discussion for a while and now it is said that nanocrystalline YTZ are more creep resistant that the submicron grain one because of Y+3 segregation. It is known that Y+3 play a role there but it is not understood which role it plays, so lots of questions. Sometimes segregation is detrimental, YTZ although has potential use as bone replacement, can not have an immediate use as Y segregation causes brittleness of the material. There are lots of interesting stuffs in this field and I am happy as I will have jobs in hand till the questions are answered. I really like defects.

Friday, September 16, 2005

A Night Club with difference!

Students from the Department of Metallurgy in IISc are extremely active, and those who work talk really little! It is reflected well for years through TMS night club talk series. Last Wednesday it was the 325th night club talk. In the campus, academic community knows about looking around, Sci forum and newly born CCS, which are perhaps much younger talk series compared to TMS night club talk series, its run by a TMS students’ chapter and apart from the invited talks, all night club talks are delivered by the students and believe me it is one of the longest running TMS Students Chapter in the whole world. We have our own world, we have our own prestigious talks, and we have our own discussions. In a faculty & staff driven institute it is really amazing that without any force (driving I meant) students volunteer to talk. The figure 325 is really huge; and it is an honour to speak in these occasions as they are the milestones for the series. Though I did no have the chance to speak in these occasions, but I have attended more that 150 talks! It covered all spectrums. From bacteria to self assembly, from ALE to casting, from NMR to DSC, from iron making to spintronix, from mobile phones to chips; we heard almost every field of material science. Technology changed, from OHP we shifted to digital projector and from the seminar hall we had shifted to Brahm Prakash Committee Room, but the character remained the same. A legacy we are carrying for a decade and it is like Prof. Ranganathan says(on some other context) “…it is in the memory of the department” . So join us at 9:30 p.m. in BPCR on Wednesday, we will share thoughts and “a cup of tea in the tea board”.

Tuesday, September 06, 2005

Materials, Mimicry and MEMS by Dr. Julia King

It’s all about fans! Prof. Julia King, from rolls royce today delivered really a fascinating talk on aero-engine in our prestigious faculty hall. When I first saw those real huge jet engines, I wondered how much science and technology must have been gone into it. She today talked about the physics, engineering and design of the fans and the engine as a whole!
Her talk started with the general concern on global warming and the contribution of aerospace industries to it. She showed a B-52 bombers emitting considerable amount of un-burnt hydrocarbon. According to her noise pollution due to high engine noise levels is also a cause of concern primarily in cities. So she addressed all the problems in sequence. Her presentation began with an animations on how an engine works. It was evident that materials design is the key for the turbines blades inside the engine! The material they use for the fans are Ni bases super alloys and there is a problem with the randomly oriented polycrystals. The grain boundaries parallel to the air flow is a bad news: they are the site where the fatigue crack initiates under cyclic loading so the blades were processed with oriented grains with boundaries perpendicular to the air flow. Final step towards this grain boundary engineering was to remove the grain boundaries, i.e. use of single crystals! No boundaries so no flaws. It is important to reduce the weight of the blades which is a new field of research and shape memory alloys and metallic foam appeared to be potential material for that. There was a job also for the combustion engineers but from the material scientist point of view it was necessary to talk about the chamber material. Composite materials were shown to have better run for that. When the discussion boiled down to noise she mentioned how the noise is generated from the engine, the solution for that was to have a turbulent mix of two kinds of air coming out of the jet, for that it was observed serrated outer wall of the jet instead of smooth wall is quite effective. The criteria was it should remain close while it is flying at low altitudes (high temp. region) and at high altitude they should open up . In a nice experiment she showed actually how shape memory alloys acts as an actuater under changing temperature; it was really a nice piece of experiment. There was an ineresting info: eagles can fly at a speed of 200 Mph and consume an energy equivalent to only 10% of its own weight. At the end of her talk she showed some video clippings of some testing on the fans. They were amazing! First one was under tremendous water flow, 2nd one was fans performance under cold condition (T= 233 K), 3rd one was what if a single blade breaks? And final one was what happens when birds hit the jet, I am not going to tell you what happens then, you have to listen to Dr. King. I could not put any of her slides which I would loved to post, may be some other day......

Game over!

Time to write some good things! It was really beautiful 4 seasons Yes! I am talking about cricket seasons. It was an opportunity I never thought I will get, but with my luck was shining at its best, I got the chance to play serious cricket after a gap of 4 years. People fall in love, so did I, with this great game called Cricket. I always felt happy when I stayed long in the crease. It won’t be wrong to say that destiny was grinning when I was batting last weekend. That was probably my last serious cricket match where I spend the longest time in the crease!
I met with cricket quite early age of my life. I had a friend called Santanu who had a proper kit; we used to play with cork balls which were extremely hard. We used to play wearing one pad, most of the players were Rightie so they used to tell me to tie the pad in the left leg, I was a natural leftie so it was the wrong leg for me so one ball one day came and straight away hit my front right leg’s sean bone, I was hurt on the my first cricket match and what a consequence, my last day was very similar, i had an injured hand; One day I had started playing it on the other day I left it. I had many friends into my life; some left me some I had left! But this is more than any pain I came accross. By this time if you are reading it you might have gave up on me but believe me its my soul speaking not me :D You had enough fun, leave me now the game is over!

Tuesday, August 23, 2005

The little angel

It happened……

Tear was about to fall, flow through her beautiful cheeks and drop on the ground. The big eyes were looking at the man on the bike. Her eyes were blank, there were no signs of grief, or happiness, it had only indifference; but still the tears were about to fall. Soft sun was falling on the asphalt road in front of the house, the road was empty and there were only two living creature on the street. Her lip was trembling, but she didn’t utter a single word, told lot of things. The guy on the bike was frozen and speechless, his mind was freaking, wanted to escape from the place as the damage was already done, but her eyes glued him to the place. He wished he could rebuild the car she was playing with, which is now laying smashed front of his bike. He was not able to understand why he should wait in the place; he tried to touch the girl with a nice tunic, but her body was stiff as if she is living in some other world. The guy was help less, she was not crying, so that he can console her. To his relief a lady came out of the house but was shocked to see the little girl on road. She rushed to her and was happy to see her untouched. The guy profusely apologized for what had happened was expecting an answer, the lady answered, “she can’t hear you, can’t reply to you; this car was her birthday gift, she received it yesterday,” The guy left the place; he had to reach his office before it’s too late.
It was becoming dark; the little girl was sitting in the small garden eagerly waiting for her mother to come. She was her only friend around and whole day she did not eat only to tell her how bad her birthday was. The car was still with her and she was trying to repair it. The road in front of their house remains deserted in these hours of the day also in the morning when she dared to go to the road. Light were slow coming up as the stars in the sky. She was quite involved with her car. She could not hear the bike coming towards her house. The same bike and the same guy approached the house. She was aware of him when she felt a cold hand on her shoulder, she turned and saw him. The whole memory came to life and this time she couldn’t hold herself, she was crying. The man was prepared, he took out a nice wrapped packet. She stopped crying and looked at it with apprehension, the packet was unwrapped and bright shinning car came out of it. The man handed it over to her. Her tear filled eyes became bright and in the whole day she smiled for the first time. The guy got his life back! Whole day he was under terrible guilt and now he felt relived and the little kid looked like an angel to him. He turned back and stared for home.

Wednesday, August 17, 2005

Jumpstart 2005: an evening with winners


It all started in a rain soaked evening in Gymkhana managing committee room, we were planning for a sports fest and at the end we decided it will be called “Jumpstart2005”. There was a whole spectrum of events held during this literary and sports festival of I.I.Sc Gymkhana. It was Santanu who was the initiator, motivator and supervisor of the show. The events included Chess, Carom, Athletics (the biggest), Swimming, and the literary events (Dumb charades and Quiz), Table tennis. We had clubbed the marathon event along with the freedom run around the campus.
The evening started with a Sharod recital, it was as usual a mesmerizing music! This was followed by a good show put up by “Rythmica” a part Gymkhana Music Club. They were also winners but on different field and different game. Our prize distribution ceremony started in the middle of the music programme. The Satish Dhawan auditorium was completely filled with people. Arjun Deviah an international athelit came as a chief guest for the occasion. The prize distribution started with ladies events. Although the female participation in field events was noticeably less the picture was different in literary events. In the male section in Athletics it was a keen contest, few performed exceptionally well, Hasta in the jumps in short distance races, Arun in short distance Run and Prakash again in jumps and short distance run. Prakash’s long jump of 5.7 m was really watch worthy. In the long distance run Claudy really dominated along with Rejin, Santosh and Sundar around, Kottada and his group came strong in relay. In throwing events Sachin was ahead of all; in discus, javelin, shot put he threw the max. In Swimming again it was “the big boy” Rejin who dominated, won 5 out of 6 swimming events, Anath also gave was a strong contender for him. In Carrom Debabrat won the singles also one doubles event, Atul, Tejaswini also performed well in doubles and in mixed doubles. Rahul played well enough to beat others in classic chess, Sachin kept his mark as a chess player along with a good athelit. Thomas outplayed others in rapid chess section. In TT Debraj showed his class and won the singles tournament, the doubles went to Kartikeyan and Ganesh. MRC lifted the departmental event by beating Physics in the finals. The last in the list were the marathoners; in the first Bangalore marathon held this year, almost 21 guys participated and we had decided to felicitate them on behalf of gymkhana, it was really a good achievement. The concluding part of the prize distribution ceremony was an inspiring speech by the chief guest. Rythmica took over the programme and it got over in an excellent note, as our ‘host’ Srini said all good things come to an end.
We had three category of prizes, first was the track suit upper, second one was t Shirt with Jumpstart logo and third one which I liked the most was the white coffee mug with gymkhana logo as well as jumpstart logo. I hope every recipient liked it!
A huge effort from Viswanath and Vivke for athletics and literary, respectively with Sushil in swimming made this big event a success, but the little man behind the screen has actually done something bigger, yes I am talking about Jackie (Santanu). I hope Jumpstart will not stop and will get some more face lifting next year. So JUMPSTART………

Monday, August 15, 2005

Freedom run


They ran, they ran in huge numbers. Cloudy morning in I. I. Sc. becomes slightly different this morning. This is Independence Day morning. I don’t know since when the freedom run has started in campus, but it is an annual event which is stored in the memory of the institute. “Freedom run” takes place on the occasion of Independence Day on 15th August. The whole spectrum of the strong 3000 community participates in this run, of course not all of them but significantly high in the no. This year the participation was nearly 250, believe me this is one of the highest participation in any athletic events in the campus. The run takes place in marathon format though the total stretch doesn’t match with marathon; the distance is just above 5 km. Starting from kids to senior faculties everyone participates in this run. The route will take you all through the tree covered campus. There was a stretch which literally passes through the jungle in the campus. The best timing was ~20 min and within 40 min. a bulk of the participant had finished their run. Today the weather was beautiful which helped a number of people to complete. The footsteps and the sweats of the great and greats in making made the streets a memorabilia.

Monday, August 08, 2005

The damned Mobile phones

I am an Engineer and I always marvel at the great technological creations of human civilizations, but not this one! I don’t know who got this idea of developing Mobile phone. This is an discovery, I put it in similar to an effect of Rutherford‘s experiments on atoms. The great soul never thought the research will lead to a killing of millions and will give the world a permanent threat. The highly misused mobile phones are of the same order, people who doesn’t need it carry it everywhere, some are real fools! Once in Rex we were watching a movie and one guy was on his phone continuously, so Guru politely requested the guy to go out of the theatre and talk. The first reply he got, “As because u don’t have cell, I cant stop using it!” and that followed with some moron (ish) acts. Even in the work places sometimes it’s a pain. God knows when human will make some more advancement and put a chip in their brains so that they’ll connect the satellite straight away and the majestical, irritating tones will ring inside their brains!

Friday, August 05, 2005

Eden gardens

Lash green out field with a 22 yard land lying bare. from the edge of the field the huge galleries have gone up to the sky. If you are in the middle you will feel like a gladiator and i can' t imagine how it will be when 1oo thousand people chant your name! It is one of my most cherished loacation on earth, I am talking about the world's one of the best cricket grounds: EDEN GARDENS.
The name Eden does not go to any mytholgy, its come from histroy. Legend is calcutta cricket club (CCC) which came to existence in the year 1792 has shifted to this place called parkland in the year 1864. This place was under the supervison of Governor Lord Auckland, and two of her family members called Eden sisters used to take care of this park and probaly from there the name "Eedn gardens" desended. The ambience of the ground was once mesmirising and heaven for the swing bowlers. The breeze from the higcourt end was nightmare for the batsmen.
Edengardens was not only a cricket ground but was a bit of football was played here also.
The first test cricket was played in 1926 at Eden gardens, between MCC vs. India and then on the ball stared rolling, from the Sobers outsanding catches to Salim Maliks devastation, Azhars golden batting and Lakshman 's epical batting, Eden is the dream ground of cricketers accross the world. The attraction is partly because of the crowd. Although breeze doesnot enter the ground still people come to watch then people.
If you happen to appear in front of the CAB office in Eden you may mistake it as the MCC office in London may be better. With the centinary museum coming up, Eden has starting from Indoor practice ground to ultra mordern Gym. Huges stands and Lights in the night. If you come to Kolkata dont miss Eden gardens, my cherished dream ground.

Sunday, July 24, 2005

We the living

I read this novel by Ayn Rand recently, i thought the title of the book will be nice title to start with and i wrote something on the book..........

This novel by Ayn Rand like her previous novels conveys a unique philosophy towards life and her way of describing it is also unique. The novel gets its life in Leningrad (or Pterograd) in Russia and it flows into different corners of Leningrad. The story is around a girl called Kira Argounova, a very strong character with a vision in life. She spends the cream period of her life in a time of political and social turmoil in Russia during the year 1917-1930. After the Bolshevik revolution and demolition of imperialism, it was the time of reconstruction. It was the time when Kira arrives in Leningrad with a new social tag; she was a “burgoa”. With the proletariat government in power, Russia was under going a social change a fresh idealism which carried out by a true proletariat Andrei Taganov. and by Leo Kovalensky(s) a young man rebelling against the totalitarian system. Kira, a character with values, could see the death of values and lack of vision in the new born society; she eventually falls in love with Leo. Kira’s father who was a industrialist now found it difficult to get bread for living. Kira and Leo both were rebellion in their own way, Kira wanted to be in the system and then revolt when she had enough strength; on the other hand Leo was mocking the system by destrying himself. The best part of the novel is the interaction between Andrei Taganov and Kira. Two completely different ideologies meet each other with some common principles and then move on parallel. The consequences of this relation are far fetched. The characters evolved with time with changing social backdrops. Corruption was taking over the regime which was based on idealism. Proletarian were replaced by corrupt escapists. The pace of the novel is fantastic, though the change in the communist reign in Russia took a long time but this book actually describes why the change was necessary. Kira who aspired to become an engineer and built a bridge made of Aluminum continued her struggle but fails. Andrei who dreamt of a society where everyone will have equal rights to live finds himself giving berth to one which lacked everything he had once thought of. Leo who wanted to live life in his own way destroys all the values he lived for. The novel is about a philosophy and it leaves a strong impression about life on you.