 Hello everyone. In the previous lecture, I discussed the applications of radioisotopes in healthcare both in diagnosis and therapy. And I also explained the three main concepts behind these applications. I would like to repeat those three concepts for the sake of continuity. And in the presented lecture, I will discuss the applications of radioisotopes in industry, environment, agriculture and food technology. Though the topic is very fast, I will just take one or two examples in each area to bring home the point. So, as I mentioned previously, the radioisotopes can be used in the form of radio tracers. The radio tracer, you can use to trace the path of an element. So, that finds a lot of applications which will be clear when we will discuss these applications. Radioisotopes are emitting radiations which are highly penetrating. And this can be used like you use x-rays for detecting the practice in human body in the bones. You can use radiations in many applications which will make things very clear subsequently. And the other aspect is that the radiations can kill pathogens, they can generate heat, they can introduce defects in the materials. So, and you can even use polymerization of the materials. So, there are, you know, you open up a new chat, new areas for applications. And this is a kind of one has to do a research, what way you can use radiations in different applications. So, this atoms in the service of mankind, that is the concept we use that not only these radioisotopes when we use, we have to have in mind, what is the benefit? So, the benefit can be in terms of money, you save the money. There can be alternative methods, you can save money, you can save manpower and you can save time. So, unless you have the gain in terms of these three parameters, money, manpower and time, if there is an alternative methodology, then it is no, there is no point using this. So, it should score over other techniques both in terms of all the three aspects that I just mentioned. So, I will just give some examples of each these three previously, one I have mentioned. Radio tracer concept in industry and the list is endless. I will give you some examples also. So, leak detection in buried pipelines and high pressure heat exchangers. So, their pipelines are going thousands of kilometers like from refinery from, you know, Gujarat to Mathura. There is a big line in refinery going, the refineries in Mathura and crude is going from somewhere in Jamnagar. So, there is a leak in this, how you detect the leak. So, and if you have to dig out the whole thousand kilometer, it is a very, very Herculean task. So, that is where the advantage of radioactive isotopes. C-page location in dams and water bodies, you can trace the path of the water by using radio tracers, flow rate measurements, what rate the flow is man, flow it is flowing, time of mixing and blending in the different types of industry, residence time distribution measurement, there are mixers and many chemical reactors, wear rate measurements by, you know, this you can you can produce radio isotope in the machine part and it is wearing out worn out so that radioactive decay as a first of time. You can see how the wear and tear takes place, sediment transport in ports and harbours, effluent dispersion in coastal waters. These are all very big experiments which the enormity of the experiments will be clear when we I will show you some results. Effective management of oil fields. So, oil field, you know, there you are is taking out the oil and then the water will gush. So, how much time we can continue to tap this oil field, there are techniques based on radio tracers, you can do the time management and radioactive particle tracking technique for flow visualization in the reactor which is copied from outside, how the particles or the reagents are moving in the reactor, you can track and you can simulate the the processes that are occurring inside that. These are some of the examples which I wanted to highlight, but I will take some of the from this and give actually illustrate more by these examples. One of them is leak detection in buried pipeline and I will give you the real examples from one of the them is Gas Authority of India Unlimited, there is a pipeline, very short explanation I will give. Suppose you have got a pipeline here and the fluid is flowing from here to here, it can be hundreds of kilometers and suppose there is a leak somewhere here. Now, how do you know, you find out where is the leak, this is the project, you cannot dig the whole line. So, what they do, they first put place the marker sources from the surface like 4W-60 sources from the surface, on the from the surface you just dig them and put above the pipeline, they are outside the pipeline and now you inject the fluid containing the radio acetyl, like methyl bromide. If it is a liquid, you can use bromine VT2 labeled liquid and then wherever there is a leak, the activity will come in the soil and now you take a detector through this pipe at a particular rate. Detector will detect not only the leak, but also the gamma ray from the markers. So, in the output of the detector, you will see these markers that they will tell you the position of these markers. So, you can know, suppose there is a leak here, you will see a broad peak here, this broad peak is due to the leak and you know this is between these two positions. So, in a very short span of time, you can identify at what place the leakage has taken place and you need to dig up only in that area to plug that leakage. So, this way you can save time, effort, money and manpower and this is a typical you know photograph, how people are injecting the radio tracer through this pipeline. Another important application of these radio tracers is residence time distribution. So, there will be many different types of chemical reactors where you mix the reagents A plus B going to some system and there is some process taking place in the system and then there is the output. So, you have an input and the output. Now, inside the reactor from outside it is blind, you do not know what is the dynamics, you know hydrodynamics of the material that is going churning in the system. So, you want to know that how, what is the time during which the reactants stay or the product stay in the reactor. So, you put a detector here, you put a detector here and then you inject the radio tracer. The radio tracer when it goes at inlet, it will show a sharp peak because it is quickly flowing in the system and the outlet you will see you will get a broad peak because inside the reactor the radio isotope leveled the material will take some time. So, for example, you are mixing sand and cement. So, you tag the sand with the radio isotope like Scandium-46 and then you want the homogenized mixer coming out of this blender. So, inside how much time it is residing and what is the informity you can know from this one. So, residence time distributions are utilized in many chemical reactors. The performance of the chemical reactors are equally determined. You can have some even industrial circuits, there can be many other plants, then mixing units, I was telling the mixing units cement and sand or there can be many other industries where you are the chemicals are being mixed. So, how well the reagents are getting mixed you can find out from the residence time distribution. So, residence time distribution is given by like ET is the fraction of species that has spent time between t and t plus dt in the reactor. So, this is the concentration of the particular species that has come in the time t plus dt, t to t plus dt and this is the integration. In the denominator you have the entire concentration total area. So, this is the total area under this graph is the concentration total concentration and at a particular time what is the fraction of activity that is come. So, this is the residence time distribution for how much time the reagent is residing in the reactor this study can be obtained. Then you have flow rate measurements they are all big projects very big projects involving hundreds of crores of rupees and you can see by what experiment one can save so much of money. In fact, sometimes you will find there is no alternative to these techniques. So, for example, if you are having a this is a actually a hydroelectric plant. So, there is a some 3.6 meter pipeline which is taking the water to the turbine. Now, the pump this vertical turbine pumps they are they have a rated capacity that how much water they will throw pump per minute or so. So, that is the capacity of the pump. So, you want to calibrate this because how much is the power consumption of this pump, what is the flow of the pump. So, to calibrate these pumps you require to do investigation and how to investigate the pump capacity the flow rate and all that. So, for this the bromine 82 can be used as a pressure. So, what you do you measure the flow rates of water. So, in water you can mix sodium bromide and so bromine will go with the flow of water. So, you can use this technique and you can put suitable detectors at initial and final stage and you can see the activity that is flowing. So, you can check the calibration of flow meters or you can check if you will flow of any fluid you know stream liquid or gas you can use. So, in fact, these are the pumps made by the industry and when they are selling to this particular thermal power company they want them to calibrate these pumps to to ascertain you have to give a certificate this is the capacity of the pump and this is the wattage of the pump. So, if you want to validate the capacity of the pump, water budgeting and optimize the power consumption then the the industry can come to the the people who are doing this kind of investigation. So, this is actually an example which the department of nuclear energy in fact, solve this problem for the industry partner. Another kind of investigation is silt movement in ports and harbors. So, what is this silt? See in the big ports you know the big ships are coming to the dock and gradually you will find that this dog height will come that the dog that the shore know the level will go up because wherever this there is a movement of the silt in the sea and so what do they do? They do a dredging. Dredging means they remove that silt and park it somewhere in the sea so that the big ships can come to the shore. But over a period of time that silt will again come and you have to do the dredging again and again so it is very time consuming. So, in fact, this is an experiment at Calcutta port. So, what was done actually that the sand particles were labeled with Scandium-46 as a tracer. So, the movement of the sand can be traced using this radioactivity of Scandium-46. So, what they do? They dredge this silt and park it somewhere quite far off and so this is the place where they have placed the dredging sand which is not tagged with the radioactivity. And over a period of time now you map you measure the activity of Scandium-46 in x-y direction and you can see here these are the contours of activity asymmetric points and so essentially this tells that these tracers this tilt can move in these directions. In this direction there is no movement. And so you can identify in which place you should put the dredged sand silt so that does not come to the port or harbor as a function of time. So, these are the kind of mega experiments which you can do. So, they are used to investigate suitability of dumping site for the dredging material and optimization of the dumping operations. So, in what place they should keep placed the dredged sand so that it does not come back to the place from where it was taken out. These are the kind of experiments you would are doing. So, these are the few examples of radio tracer application where you trace the path of a radio isotope and then you can trace the path of sand, you can trace the path of a chemical, anything you can trace the path of a fluid even water body you can trace the path. The other application is penetrative power of where the gamma rays are penetrating through solid material and they follow this exponential decay i equal to i0 raised to minus mu x where mu is the attenuation coefficient. So, these techniques are called non-destructive testing methods NGT. NGT you know very useful in the industry for measurement of thickness, density, defects in the materials. For example, in the high technology materials there is some welding to be done. So, how good is the quality of the welding because they are going to remain in the plant for long long times. If the welding is not proper it will affect the integrity of the system and for that gamma radiography is used extensively in industry. In fact, we train the people who do gamma radiography in the industry. So, there is a training program in the Department of Atomic Energy one can enroll for that and do the certificate course and then you can become a radiographer. So, the non-destructive examination of welds and castings this is not the only example you can have many other examples you require you have a high energy gamma source and low energy gamma source for radiography. If it is a heavy material big bug equipment you require high energy gamma typically a cobalt 60 of 20 kilo 20 curie and if it is a smaller product you know some smaller machine then you need to have low energy gamma emitter and 100 curie of EDM 192. So, like welders pressure vessel ships aeroplane components all can be investigated for their integrity their structure there is no crack inside micro cracks you know there could be micro cracks the NDT the radiography can tell you even micro cracks and so this is a typical example of a a component you know a component which has got thick parts and thin parts. So, when you when this is a this is the area where is thin wall that means it is a doesn't have much thickness. So, when you do gamma radiography with low energy EDM 192 you can see some opaque part but when the same thing you see in gamma in cobalt 60 we don't see that part because gamma energy which cobalt 60 gamma will just pass through. So, by playing with the gamma energy you can investigate the different types of samples small or big and this is a typical gamma camera called roly developed by Brit the board of reducing astro technology BAE. So, this this can be taken and you the the source is kept inside the shield and when you want to do the radiography you take out the source from the shield expose the sample and again after the exposure you take it back to the shield. So, it can be transported in different places for NDT experiments. So, these are the kind of you know big machines radiography of aircraft engine of concrete structures or even the plug valves you know the small as well as a big you know aircraft and the big machines can be done you need to do radiography because you have as a part of the quality control you have to assure the end user that this will meet those requirements. So, when you say an aircraft you know the like the the probability of accident one in billion times how that number comes because they have undergone through tough test flight this kind of testings. Now, I come to the another NDT technique called computer thermography CT CT. So, computer thermography is an advanced version of radiography where you not only do that take the image you get 3D image of the equipment. So, NDT of engineering and industrial specimens you can do even cross sectional images of the internal structure of the object. So, in radiography you just expose the equipment to the gamma rays and you take the film it take a film on which you can take the image of the like you take an x-ray. So, radiography is like x-ray but tomography you know is much more advanced. So, you have an object you put the object here there is a there is a source inside this shielding. So, there you could come as a beam through this collimator and you can do x, y, z movement of the object by a gonometer and then the gamma ray will go and by a collimator will fall in the detector. So, what you do you rotate the object in x, y, z direction in the form of thing. So, you get image cross sectional image of each slice of the object. So, you can you can go take it up you get the circular plates circular images you take in x, y direction you get different cross sectional area and those images are constructed by the computer and develop the 3D image of the machine part. So, this is the more advanced version of radiography in where you you get the 3D image and these 3D images are then you can see you such a crystal clear image you get after computer tomography. So, this is a typically a cold bed test reactor you can see the kind of image that you get by computer tomography the full digital radiograph 3D surface rendering from CT data and representative. So, you can see the kind of dilution that you get because you have a collimated beam of gamma ray and then you get the image. So, as in one scan you will get a particular plane of the system and you have thousands of scan in x, y, z direction. So, that is the kind of dilution that you get, micron levels of fractures you can detect using computer tomography. This is the image of a typical metal or ceramic handicap of electronic equipment. So, again the point I want to emphasize that by computer tomography you get much more well resolved images than the normal pedography. Another application is in gamma scanning. Gamma scanning is another area for troubleshooting investigation. Do you have suppose you have got this what you call as the fractional distillation in the refined region you have big towers and the big towers different heights will have different collections of different types of products of the petroleum products. So, now you this these are you know they are working for long, long time and there is some defect inside is it you are not getting product of desired quality. So, how do you rectify? You see you open it up for maintenance you know it may require shutdown for a week or two and that is huge loss to the industry. So, what you do non-invasively you can do you put one detector you put a source over 60 source here and you put a detector sodium iodide thalium detector and they are they are they are moved synchronously. So, if this source moves detector also moves by the same. So, they can they are joined together. And now what you are getting is the this this attenuation of the gamma ray of over 60 when it is passing through the internal parts of the column. So, this column so this is the cartoon of the column there are different plates inside you know different fittings are there. So, the gamma ray intensity you will see. So, when the gamma ray is passing through a thick object the intensity will be low. So, that tells you the profile of the different objects inside the column. Now, if you have taken this profile in the beginning when the column plant was started and you can periodically monitor. So, as a function of any time suppose there is a problem in the plant you can immediately run the scan and find out there is a flaw. So, this scanning of this column and it is very low cost a cover 60 source and like detector sodium iodide thalium is not at all very costly. So, manpower will be one or two personnel and even a day you can do the whole investigation. So, you save the time money and the manpower and by very very low cost very low short time you can do troubleshooting of the problems that are occurring in the plant. So, the diagnostics of problems in operating columns like fractional distillation, separation, stripping etc. in petroleum plants. So, very quickly many of these defined reason in Lusanne petroleum all many in the petroleum companies employed these techniques to do troubleshooting whenever they have problem in the plant. Now, I come to the another aspect again the penetrative power of the radiation is called the thickness gauge, look newly gauges. So, you can you can determine the density, thickness, level of a compound and so on. So, measuring the and monitoring the thickness of films, sheets and metals and plastics during manufacturing. So, you have a like giving a paper industry. So, the paper industry paper is prepared and it is moving through a conveyor belt and you know the paper quality you say this much you know gram per square meter gsm 100 gsm, 50 gsm and so on. So, how do you maintain that quality control you want to know. So, for that you know you can have a very simple system you have a radiative source outside the this is the paper which is moving above the paper you have a source below the paper you have the geiger ruler counter very cheap equipments and you suppose it is a it is a for example, if we have a metal plate you can put beta, if we have a thicker plate you can put gamma, if it is a thin paper you can put it in all forms and then measure the activity as a function of time. So, suppose it is the thickness is constant you will get constant activity in the counter, but whenever there is a change in the thickness that intensity will change. So, beta and gamma can be used to find out the change in the thickness whereas, alpha in the case of alpha the energy of the for a very thin foils you know micron thick foils you can use the change in alpha energy because alpha intensity will not change as a much thickness, but alpha energy will change. So, for very thin foils micron thick or less than that you can use alpha and for millimeter thick to millimeter you know you can use beta or gamma sources. So, they have the advantage of non-contact movement you can place it even the plant is running you can do continuous measurement accurate save and reliable there is hardly any ventilants the plant need to shut down gauges can be often installed and commissioned without processor down and at the sources and detectors are mounted externally from the vessel or process they are completely unaffected by the chemical and physical property of the plant. So, it is you know non-invasive the plant is running you can do all in the modification in the in this system to determine the thicknesses without affecting the plant that is the kind of advantage with this. Like you know the examples are level gauges oil level in refinery you know refinery the vessels are few thousand very big ones lakhs of liters plants. So, this level level of the fluid you can do you have a source and a detector you will put a source and detector and you can play them. So, when the gamma source is below the level you will see the high attenuation and when it is above the level there is less attenuation. So, you can see there will be a discontinuity at the level. Similarly, you know this when you have the mixers and so there is a uneven level inside like clickers you know they are used in cement industry. We put a source and a detector here and from the attenuation the intensity of the gamma in the detector you can see the level of the material inside the this this plant. The glass furnace the glass the molten glass what is the level of molten glass you do not know from outside but if you put a source and a detector source and detector that attenuation in the primary when it is going to the molten glass there will be more and if it is above the molten glass level it will be less. So, you can again see very precisely you can find out a level of the glass furnace. So, level gauges and similarly you have density gauges and so on. There are many many areas where you can use this radioisotopes. Okay lastly I will discuss the applications based on radiation effects the heating the killing of pathogens and so on and there are I will talk about three areas. One is the agriculture. In agriculture you can do crop improvement by radiation induced mutations. Radiations when they are bombarding the seeds then they can generate normally the seeds are undergoing mutations even our body is undergoing mutations but that is happening at a very very small times 10 power minus 5 minus 6 scale. But by mutations you can accelerate the mutation by radiation acceleration mutation by orders of magnitude 1000 to 10,000 times faster mutations can take place. Food technology the radiations will kill the pathogens you can do disinfestation and you can delay the ripening of the fruits and you can do sterilization of medical products again the pathogens can be killed and also the radiation processing you know radiations can induce polarization in materials. So, like rubber the bulk management of the rubber can be done in your radiations you can hydrogenize the sewage sludge and use it for the manure in cities now it is a big problem of sewage sludge. So, you can make it hygienic by using radiation and then you can use it this manner during of surfaces coatings heat shrinkable forms you know in radiation technology is a past area there are more applications you can modify materials you can graft a compound on a solid support there are a lot of modification processes using radiations because radiations can induce crosslinking in material polymers it can even cause chain season like teflon can be powdered by radiation but the normal polythene become hard by crosslinking. So, I will not touch upon this aspect because I do not have much time I will just quickly give you the example of the first three. So, in agriculture you can do crop improvement by mutation as I mentioned the mutation radiation induced mutations you can enhance the mutation by radiation. So, they irradiate the seeds by gamma rays the gamma ray will cause genetic changes in the seeds and then you will show these seeds. So, apparently we cannot say what will happen to the seeds we cannot selectively generate positive mutation. So, mutation can be negative. So, you you will come to know after you reap the harvest the seeds the mutation can be positive that means the fruits that you generate for out of this mutated plants they can have good traits positive traits or there may not be any mutation no effect. So, once you show them once you harvest them then you pick up the ones which have the positive traits. So, the genetic variation you see and select them and multiply them 5-6 cycles. So, once the genetic changes have become stabilized then the varieties released the government as to their government agencies which will approve that you this is now certified to use by the farmers. So, what are the traits what are the attributes that you can have I yield variety. So, per hectare omniquitans that is a parameter disease assistance this the after genetic modification they have you know the mutations they have become more this is the one adopted they can adopt you know the desired conditions or topic and conditions or better nutritional nutrient value. So, these are the parameters which you can see if they are improved then you know that we have produced a good material. Second is the applications in food technology you can prevent the sprouting of vegetables because the radiation will kill the the the the enzymes and bacteria they will deactivate the enzymes they will kill the bacteria you can extend the self-life of perishable food products because you can delay the growth of the microorganisms you can disinfest the food products spices many products meat products, canned food products you can preserve for longer time and you can delay the ripening of fruits like mangoes. So, this is a typical you know the plant for radiations and so many products have been certified approved for radiation by gamma rays, potato, onion, many several types of food products are now certified for radiation by the gamma rays. So, there is a long list of products I have listed here meat, meat products, chicken, spices, onion, potato, ginger, garlic, shallots, mango, rice, all these products are now certified for radiation to improve their self-life or to do disinfestation. Lastly as I was mentioning you can stabilize medical products using a radiation plant and this you know so you pack the implement the medical devices like you can usually throw types of medical syringes, surgical gloves, tools used in surgery, tweezers, scissors and so on and you pack them in cardboard boxes this these are the cardboard boxes and you put them so there is a source in the plant and this in the conveyor belt this whole the packets will go stay there for some time and after proper dose has been delivered they will be taken out and then sent to the places hospital, sword industry. So, there are several plants in the country now running and one of first plant was Isomet at Trombay for the last month now not three more than four decades it has been working and this industry is very much growing now. Now, people have radiation plants not only for medical sterilization but also for food technology, food preservation. So, combination of medical sterilization and food technology are making the throughput high and many people private people are now developing these radiators for the benefit of mankind. So, that is all I had to say I wanted to bring home the point that not only the research should be done for the understanding the system for underpinning phenomena but the research that is going on the laboratory must reach the land and for that you need to have innovation development of technologies. So, you do the research then develop demonstrate and deploy so any research should be ultimately going to useful for the mankind. Thank you very much.