[ sound] Hello everybody.[ vocalized-noise] So, welcome back to theclass once again, so where we are talking about the asbestos fibers. And what we have seen[ vocalized-noise] thatone particular motley, that aims, one particular group can be useful[ vocalized-noise] formaking these particular type of fibers[ vocalized-noise ]. So, the purpose of this determining is that wecan have a diaphragm, we know that a particular type of filtration process can be achievedthrough[ vocalized-noise] a diaphragm. Diaphragm can be a piece of cloth also[ vocalized-noise ]. So, chlor alkali diaphragm layers wherewe can use it can have a conventional call as the sheath also[ vocalized-noise ]. So, the chlor alkali process we already seenearlier in our one of our previous classifies, several categories mostly[ vocalized-noise] we have discussed the chlor alkali process.So, the chlor alkali diaphragm sheath[ vocalized-noise] used for making the chlorine. So, there we can use that special diaphragmand these diaphragm is likely to be[ vocalized-noise] made of your this specific asbestos cloth.[ vocalized-noise] Then we can use this asbestos material as vinyl flooring tiles, because these are the correspondingsupport material because the original material can be of vinyl polymer, but the vinyl polymercan is in favour on the asbestos textile[ vocalized-noise ]. So, vinyl storey tiles we know that the differenttypes of floor tiles or the floor expanses we mostly use[ vocalized-noise] which is foldablealso .[ vocalized-noise] Then the flooring expanse alsotiles are very hard and attended their most thickness is also very high.[ vocalized-noise] Then sometimes the vinylbased cements are also there, where some amount of asbestos is there.[ vocalized-noise] Then as a very useful fire proofing material, so we can have the fireproof for your wallsof the residence,[ vocalized-noise] then any other places where we can have some chances of catchingfire even in the laboratories[ vocalized-noise] or service industries,[ vocalized-noise] becausethis particular information the asbestos will not very quickly take fire or take fire.[ vocalized-noise] So, one such example isyour gauntlets that which are capable of bear a very high temperature, because it can have alsothe insulation material[ vocalized-noise ]. So, gloves, a gauntlet made of your asbestosmaterial which can withstand a very high temperature also you can positioned that gauntlet and we can holdsome hot rod likewise[ vocalized-noise ]. So, it can have a good hot fighting aswell as it can have a ardor proofing substance too because this with this glove[ vocalized-noise] you are eligible to hold any open fire too[ vocalized-noise ]. Then different kinds of industrial and marinegaskets we can use.So, the different types of industrial andmarine gaskets because that[ vocalized-noise] whether we can have some division, that represents, industrial gaskets which is filling some place[ vocalized-noise] or which in some you canhave some valves.[ vocalized-noise] So, valves we are able to have somegaskets we know that most of the time it is the rubbery material,[ vocalized-noise] butthe asbestos can also be a very good material for as the gaskets. Because that asbestos strands we know[ vocalized-noise] that we can put in the plumbing also in for the water lines likewise[ vocalized-noise] wecan use this as the corresponding yarn .[ vocalized-noise] Then different types of thermal pipe insulation, because the thermal tube is there and we dontwant to go for loss in that special temperature of the thermal hose.[ vocalized-noise] So, we situated this particularcovering with that of your asbestos cloth.[ vocalized-noise] Then filters of removingfine particles, just now what we have seen in case of your preparation of your chlorineas the sheath reaching process, or the diaphragm constructing process. So,[ vocalized-noise] if we can uniformlyput those corpuscles or those fibers that is asbestos fibers then we are able to have some threadingof those asbestos fibers,[ vocalized-noise] so fine mesh sizing can be generated such thatonly big corpuscles of a particular mesh such as your 10 or 20 mesh immensities can passthrough that special sheath others will be retained. So, it can be used as a filtering materialthat means, the ocean; that signifies, the cellulose located filter newspaper cannot be useful sometime[ vocalized-noise ]. So, asbestos located filtering information, filteringmembrane or diaphragm can also be useful sometime[ vocalized-noise ]. Then one more important thing is that thedrilling fluid supplements, because when we drill that skin-deep of our earth to get irrigate, to get oil, to get gas, we use some drilling fluid. So, teaching flowing is likely to be mingled with theseasbestos fabric. So, it has some good advantage for additionof this specific asbestos textile, asbestos fiber or powder sometime[ vocalized-noise] to get a good type of these teaching supplements for this your instructing flowing. Then HVAC flexible duct connector. Because nowadays for[ vocalized-noise] thiscommon the heating, that vacuum-clean, then ac thing in the apartment or the lab or the industryplaces,[ vocalized-noise] we can have the in live concluding of the heating process, vacuumof that particular that means, we want to evacuate some time and that the natural acprocess[ vocalized-noise] that planneds, cooling of the breath or the heating of the breath is required, and we can supply fresh air from the outside[ vocalized-noise] we can supply through someduct to the different laboratories, different rooms and different cavities mostly .[ vocalized-noise] So, we can have the flexibleduct and the majority of them passages are made of with these asbestos information. So,[ vocalized-noise] very useful use andthe consumption of these making this resilient canal connector is with that for stimulating thedifferent HVAC groups.[ vocalized-noise] Then what we see that we can have four important asbestos forms. What we can find now[ vocalized-noise] thatwe can have four important asbestos characters and these asbestos types what we have seenthat[ vocalized-noise] by reputation we can have,[ vocalized-noise] so chrysotile, crocidolite, anthophyllite and actinolite.So, these are the refers basically and sometimesit can be very difficult too to remember.[ vocalized-noise] But if we think in termsof their correspond substance structure[ vocalized-noise] will always be interestedas an inorganic chemist that what should be your correspond compound piece ofthese four different ranges.[ vocalized-noise] So, first one mostly the chrysotile, chrysotile basically the chrysotile is your typical materialwhich is basically magnesium silicate. As we all know what we use day-to-day as difficultdifferent types of talcum powder. What is talc?[ vocalized-noise] Talc or the talcum powderis nothing but your hydrated magnesium.[ vocalized-noise] So, this is also that sortof hydrated magnesium silicate of different structure.[ vocalized-noise] So, chemical compositionof information materials of this asbestos type is typically that of your talc or talcum powder[ vocalized-noise] is basically made up of your simply magnesium silicate which is hydratedof different level.[ vocalized-noise] Then crocidolite, crocidolite is basically is correlating one where you have iron youdont have any magnesium you have sodium and iron along with a huge silicate structure .[ vocalized-noise] So, all these materialsare a very complex silicate structure. So, mostly these are silicate materials.[ vocalized-noise] So, we are studying we arestill continuing with those silicate cloths of very helpful in the different purposes.[ vocalized-noise] Then anthophyllite anthophyllite is again we bringing the first category of magnesium theniron,[ vocalized-noise] and of different types of the silicate material and the large numberof hydroxy groups are there[ vocalized-noise ]. So, those hydroxy radicals is likely to be the terminalone attached to your silicon or can be attached to your the correspond metal ions center.[ vocalized-noise] Then actinolite, actinoliteis basically based on your calcium magnesium thing.[ vocalized-noise] So, when you find this chemical arrangement, we will always fantasize or talk about the differentstructures,[ vocalized-noise] and those different organizes of these materials are of differenttypes[ vocalized-noise ]. So, chrysotile and amphibole asbestos havea considerable[ vocalized-noise] force on their physical properties.[ vocalized-noise] So, the arrangement andthe structure will tell us that no it can have a different physical quality as wellsuch that you can have a different structure. So, it can[ vocalized-noise] basically modifyits characteristics or the physical properties or the physical behavior[ vocalized-noise ]. So, chrysotile asbestos fibers consists ofbundle of hollow micro fibers.What are those?[ vocalized-noise] Those are packets of hollowmicro fiber, so those that is why these are interesting to know what are known as thedifferent types of micro fibers, we known as fibrils. So, these are the normal term what we usein the biological statement also[ vocalized-noise] in the bio organic chemistry or the biochemistrywe know the the protein fibrils.[ vocalized-noise] So, the fibrils are hollowmicrofibers nothing but this. So, “youve had” the very small channel.So, these are the hollow microfibers[ vocalized-noise] of fifteen to 40 nanometer in diameter. So, diameter is also not very much it is onlywithin 50 nanometer[ vocalized-noise ]. So, when we go for these asbestos fibers, so we can have a particular process. So, industrial distillation or industrial isolation[ vocalized-noise] can be used through a cool process. How it starts? It began with mashing and tightening or batchesof[ vocalized-noise] the raw asbestos materials which are coming out of the stone .[ vocalized-noise] So, the stone textile isa starting cloth. So, the amount cliff textile we can go for theloosening[ vocalized-noise] of those boulders with the jaw crushers. So, mouth is there. So, the jaws we are familiar[ vocalized-noise] thatthe mouths can take out and then remove those fibers or the[ vocalized-noise] correspondingmicro fibers also.[ vocalized-noise] So, one of the following options that makes two things we use mostly the jaw crushers, these arethe common instruments industrially beings use all the time one is the jaw crusher[ vocalized-noise] another is the double roll mills[ vocalized-noise ]. So, the jaw crusher will separate and doubleroll mills can roll. And bundle of those special type of asbestosmaterial like that of our jute fabric what we get which is also a plant material. So, bush substance which we can settled as isa very good fiber. So, asbestos is like of that of your jute, and we use it in the double roll mill[ vocalized-noise] to for their rolled we can consider thisas the wheel mills too.[ vocalized-noise] So, one particular process is known as the soaking process.When we follow this particular wet processfor determining these it is an opportunity to for narrower fiber portion distribution to be obtained foramphibole asbestos. So, when we become these amphibole asbestos, so we basically pass narrower fiber segment dissemination. So, the rationing so everything is notuniform,[ vocalized-noise] but most of the time we will find that one particular varietyof fiber section and its spread was essential[ vocalized-noise] to give a characteristicpattern and the characteristic structure.[ vocalized-noise] So, we separate it fromthe stone textile how by mash or the crushed potpourrus by using a hydro cyclone and the longerand shorter fibers are separated with a rotary pan. So, we have a rotating sieving[ vocalized-noise] mechanism such that the longer one will be separated from the shorter one.So, shorter are likely to be[ vocalized-noise] separatedat one point and the longer are separated out from that particular segregation process.[ vocalized-noise] Now, once we have the differenttypes of these fibers, their microfiber designs, their segment, and all these things are usefulbecause a particular type of behavior or special type of use or special asset of thoseasbestos cloths are dependent upon the type, what asbestos type “youve had”, what asbestostype we are getting from the natural mood[ vocalized-noise] or from the natural cloth .[ vocalized-noise] Then where from we get that special type of deposit like that of your geographicalorigin or geographical origin of that particular cliff collection.[ vocalized-noise] Then certainly, the chemicalcomposition when you go up to that end,[ vocalized-noise] either you have magnesium, whether you haveiron and how much of silicon is there, and the silicon design.[ vocalized-noise] Then the fiber section as we have seen just now the shorter length and the longer lengthwe can separate it out, so we can use for one particular purpose the shorter fiber duration ,[ vocalized-noise] and the longer one for the other purpose,[ vocalized-noise] then degreeof rotting if we want to degrade this. If we want to get the powder material outof those fabrics, so it can also be dependent on the strength of that special material, and how quickly we can cheapen this specific[ vocalized-noise] material for our use.So, the largest quantity of these asbestosare the different types of asbestos composites we are able to reach. So, what we see now that we can use that wecan throw those asbestos fabric in some other material like that we know that in metal scienceor the polymer science[ vocalized-noise] that we attain some composite information, where thebasic material is your polymeric textile. And we set something else such that we canincrease the strong, the durability, the structure, the its corresponding affinityfor paying different influences will be changed.[ vocalized-noise] So, when we use asbestos as a composite substance or composite piece to get the composites isknown as asbestos composites.[ vocalized-noise] So, these asbestos compositesare utilized, the most important application is our cement application, because we willbe seeing maybe in our today’s class or in the next class how we stimulate plaster is the most[ vocalized-noise] handy cloth what we utter the inorganic pharmacists keep the correspondingindustrial sector because we use it large amount of cement we use it, but the basicidea or constructing up all these things is your conventional knowledge of inorganic chemistry[ vocalized-noise ]. So, how we get that cement cloth? So, right now when we are talking about thisasbestos cloth tell us know how we can improve the strength of that special plaster information. So, if we settled that wants, you can have a composite, why we realise these composites again including lingo, these are the general terminology.[ vocalized-noise] The buttres that aims, we are increasing the strength of that particular cloth such “that were going” have some impregnatedthing[ vocalized-noise] that like that of our linchpin type of thing, where reference is positioned therod in the concrete, it varies the corresponding backbone of this piece of the building.So, in some other form, the reinforcementfor the concrete substance not only by the addition of the gravels or the beach,[ vocalized-noise] but the add-on of the asbestos material will giving you the correspond cement[ vocalized-noise] as the asbestos plaster.[ vocalized-noise] Then some organic materialwe can put inside it. So, the organic material when capturing thisasbestos cloth as the[ vocalized-noise] ring-binder substance as the organic binder thatmeans the polyvinyl chloride[ vocalized-noise] then other synthetic rubber or the naturalrubber such as that of your neoprene rubber.[ vocalized-noise] And some of the duromersthat implies, the polymeric items having higher stability is known as duromers[ vocalized-noise ]. So, duromers can have your ring-binders which cantrap those asbestos to use these composites.[ vocalized-noise] So, where we use basicallythats why the reinforcement can be achieved for cement,[ vocalized-noise] can be achievedfor PVC, can be achieved for rubber, and can be achieved for the duromers. Then how we define a particular type of compositeany kind of composite is a general expression.[ vocalized-noise] So, the composite when wethink in terms of the asbestos, we can consider it as asbestos composite[ vocalized-noise ]. So, we supply the fiber the asbestos fiber. When we supply these asbestos fiber to thecement material, plaster is the powdery species what we will see[ vocalized-noise] in ournext class maybe that the gunpowder fabric when is mixed with liquid and we allow it forsome defining duration, we get something but we can get the plaster of some building[ vocalized-noise] or we get some the correspond concrete[ vocalized-noise ]. So, when asbestos as the correspond fiberis given, so we take one very useful or well known cement type[ vocalized-noise] is knownas the portland plaster .[ vocalized-noise] So, this portland cementcan be reinforced with up to a 10 to 20 percent[ vocalized-noise] preface of the asbestosmaterial and chrysotile asbestos is added such that you can improve the correspondingcement substance when we go for its harmonizing met as the correspond concrete realizing orany other type of use. So, we see now that how we make this asbestoscement. So, if we get that, because this is a drymaterial that asbestos itself is a baked fabric,[ vocalized-noise] after dehydration like thatof your zeolite heavines we envision[ vocalized-noise] that we can get this asbestos for this particularpurpose[ vocalized-noise] that you can have this asbestos cement. So, you get that the slurry of the cement. So, asbestos will be put inside[ vocalized-noise] with asbestos fibers is filtered. So, slurry of cement with asbestos fibersis filtered placed under mildews at a very high pressure and left to set for 24 to 48 hours.So, you interpret within 1 or two days it will beset. So, asbestos cement substance or asbestos concretematerial can be established[ vocalized-noise] if we have the add-on of asbestos substance tothe slurry of plaster.[ vocalized-noise] So, different types of consumer products we can make out of this asbestos cement, wherethis asbestos impregnated cement very to meet the different types of boards, differenttypes of roof singles; that means, asbestos ceilings we all know that we can use as the asbestossheets for roofing,[ vocalized-noise] then the different kinds of tubes and the moldedproducts. So, one such is your the corrugated type ofasbestos sheet, what we can use as the ceiling cloth for meeting rooms. So, we gets the idea that asbestos materialis a frequently fiber cloth. So, we get a general period for this cementis the fiber cement.[ vocalized-noise] So, what is that fiber cementfiber cement is therefore a composite building[ vocalized-noise] or creation textile[ vocalized-noise] used in roofing and facade makes that implies, you can have the plasterof the[ vocalized-noise] walls likewise because of his persuasivenes and durability.So, we can improve. So, is a mostly a value addition we canimprove the corresponding caliber of the cement because we know will see likewise that large typesof a large[ vocalized-noise] number of different types of plasters are there, where your silicacontent is different, where iron oxide content is different, our alumina material is different[ vocalized-noise] or also the corresponding addition of slags giving you the slag cement[ vocalized-noise ]. So, if we have a pure variety of that cementpowder and cement gunpowder we putting sea we get the slurry and that is fixed[ vocalized-noise ]. Now, after the additive of this asbestos fiber, we get the fiber cement which have[ vocalized-noise] higher persuasivenes comparison with your originalstructure what can be obtained from the powder plaster.[ vocalized-noise] Then we will see something as your glass fibre, which is also a very useful fiber inorganicfiber what we can must be considered[ vocalized-noise] and we can use this or we can induce those fiberslike that of your textiles also.So, we can put in the textile substance alsoor the textile like of these fibers we can have,[ vocalized-noise] like that of yourplastic material. So, the polymeric information the nylon fabric[ vocalized-noise ]. So, the plastics could be reinforced by glassfiber. So, some plastic material if we can placed orif we can put inside the correspond buttres textile as your glass fibre,[ vocalized-noise] you can have a different type of textile we can obtain[ vocalized-noise ]. So, large number of this type that necessitates, the glass fiber in pregnant plastics or the textile fibers in can have[ vocalized-noise ]. And now to simplify that nomenclature of allthese things instead of leaving a complicated word of geological source,[ vocalized-noise] we can have the typical A, B, C, D type of nomenclature[ vocalized-noise ]. So, the first range is known as E-glass. What is E-glass, E-glass is nothing but yourtextile fiber glass[ vocalized-noise ]. So, E-glass will be made of a particular typeof glass, which is calcium aluminum boron silicate glass, because the glass we knowa particular variety of[ vocalized-noise] your sand silicon dioxide merely. So, when we leant boron in it, we get the borosilicateglass[ vocalized-noise ]. Then sometimes a better quality of that particularglass can be improved by the addition of aluminium as well as calcium. And it can be used for your polymer reinforcementand work is in the typically in the electrical sector,[ vocalized-noise] becauseif “were having” this glass substance we can have the insulation that conveys, the[ vocalized-noise] corresponding plastering of the simple wire.The electrical cable basically, because wewant to have the normal isolation of the electrical cable for high-pitched voltage transmissionalso. So, the electrical engineering industry canbe very much dependent on this particular type of E-glass variety for its reinforcementin the polymer[ vocalized-noise] for membrane of the cables[ vocalized-noise ]. Then the next one is the -Aglass, -Aglassis the very basic glass what we know that which is obtained from your sodium silicates ,[ vocalized-noise] which your soda-lime glass. So, sodium silicate as well as some calciumbased lime is added,[ vocalized-noise] calcium oxide is added or calcium carbonate is supplemented. So, is it can have the little expecting application, but you can have the very basic material you can make for making this soda lime glass forit[ vocalized-noise ]. So, the third one is basically apart fromyour lime and alkali that entails, soda and lime you articulated boron, boron previously we know[ vocalized-noise] that boron can improve the quality of the correspond glassy information[ vocalized-noise ]. So, it will have a high chemical resistancethat is why the borosilicate glasses we use that that of your corresponding, where theglass cables for our laboratory utilization or manufacture used to support industrial chemicals[ vocalized-noise ]. Then you can have the D-glass, another varietyafter C is the D for high-pitched dielectric requirements[ vocalized-noise ]. So, you vary simply by the correspondingglass type[ vocalized-noise] then we can have R-glass, S-glass and all different sorts ofglasses we can have,[ vocalized-noise] where you can have a high mechanical requirement at hightemperature.So, it is feasible have high-pitched persuasivenes mechanical strengthwill be more and it can withstand a high temperature likewise[ vocalized-noise ]. Then the other assortment what we can think ofthat one is known as alkali-resistant glass, which is known as air glass[ vocalized-noise ]. So, you can gave once “were having” seen thatit can have a very high temperature bear if we use zirconium dioxide or zircon[ vocalized-noise ]. So, zircon containing glass with improvedresistance to alkali. So, we can have all smorgasbords, one can beof acid defiance,[ vocalized-noise] one can be of alkali resistant, one can be oftemperature resistance[ vocalized-noise ]. So, these things can be very useful and somewill be simply chemical resistant that represents, any other kind of chemical[ vocalized-noise] can be handled with the use of that special material for becoming of any type of tube orany type of[ vocalized-noise] other flexible textile for implementation[ vocalized-noise ]. So, the other one other most interesting oneis our use of your optical fibre, so that glass fiber what we know that optical fibercable[ vocalized-noise] in the communication sector, through electronics engineering peopleand electronics manufacture as well as the telecommunication industry is very much dependent on this particularfiber,[ vocalized-noise] but it has a usual parentage of inorganic cause[ vocalized-noise ]. So, the industrial in organic chemistry canalso be benefited from the knowledge of fixing of optical fibre,[ vocalized-noise] how industrycan start for making this particular type of glass fibre[ vocalized-noise ]. So, what is that optical fiber, why it isspecially mentioned and specially crafted[ vocalized-noise ]. So, it can have a core glass arrangement. So, so the core of this material the fiber, it can have a good core[ vocalized-noise] and this core is basically made up of glass[ vocalized-noise] with a high refractive index that entails, germanium dioxide or phosphoruspentoxide narcotic quartz glass, is a special variety of glass,[ vocalized-noise] we maynot get it ah naturally from the market[ vocalized-noise ]. So, it is a special variety of glass and theprice of this glass would be therefore, emphatically higher,[ vocalized-noise] because you improvethat to its implementation of its now high-pitched refractive index[ vocalized-noise] such that you can have thetotal internal thoughtfulnes[ vocalized-noise ]. You can have a material prism like materialand you go for total internal thoughtfulnes[ vocalized-noise ]. So, total internal reflection will carry theinformation, carry the light-footed, carry the meaning with that of your optical fiber[ vocalized-noise ]. And one is your cladding glass that claddingglass is shielding your core glass. So, the cladding glass will have a lower refractiveindex. So, any other kind of[ vocalized-noise] normallyused glass, what we use in the laboratory too can be used[ vocalized-noise] such thatyour borosilicate glass or the fluorosilicate glass[ vocalized-noise ]. Sometime we can use the plastic material evenalso,[ vocalized-noise] like silicon resins likewise and the different types of fluoropolymersalso, “its not” that[ vocalized-noise] you can you have utilized other glass also,[ vocalized-noise] but your core is of different types. So, core glass is the important factor formaking this particular type of optical fiber[ vocalized-noise ]. So, we are able to have two steps mostly for it, one is your step index fiber, so two types they are; so step index fiber and anotheris the pointed index fiber. So, step index fiber you reform the indexof your refractive index in a stepwise manner. So, constant refractive index in the fibercore[ vocalized-noise ]. So, you cannot change that special refractiveindex and another is the evaluated indicator fiber[ vocalized-noise] continuously decreasingthe refractive index from the fiber core to the outside of the fiber[ vocalized-noise ]. So, whatever refractive index you have atthe core which is decaying down, when you reach to the outer surface of the fiber,[ vocalized-noise] so that is the particular type of idea and special type of technique can be usedfor making this particular type of glass fiber[ vocalized-noise ]. So, step index fibers what we consume or whatwe make are manufactured by which way[ vocalized-noise ]. So, step index fibers are manufactured byusing the perch and tube or the double crucible process.So, the process of making this particularstep index fiber is by perch tubing or the double crucible process[ vocalized-noise ]. In which particular process the core and thecladding glasses, because we have seen that we can have two different types of glass; one is thecore glass, another is the cladding glass; one is that the core and another is coveringit[ vocalized-noise] or in the molten state.And they find themselves in the molten state separatelyfrom ultra pure gunpowder, because[ vocalized-noise] pollutant will be a detrimental thing for allmaking of all these things. So, the purity is very high that is why[ vocalized-noise] the cost of these glasses are very high, apart from its involvement of Ge O 2 or P 2 O 5[ vocalized-noise ]. The piety questions too, because we are dealingwith something of high-pitched accuracy material.So, this high precision material you can haveonly if you have 99.999 percentage piety with respect to a particular variety[ vocalized-noise] or a particular material[ vocalized-noise ]. So, the core of this particular one is formedfrom the ultrapure pulverize we its utilization and that ultrapure pulverizes are transferred into twocrucibles. So, you should have a very good idea or verygood knowledge about what is known as crucibles we know[ vocalized-noise ]. The very small crucibles, the nickel crucible, the porcelain crucible, the[ vocalized-noise] sintered base glass crucible, use in the day-to-daylaboratory classifies in all chemistry laboratory categories we use[ vocalized-noise ]. So, if we use it in a bigger size, it willbe of semi industrial scale;[ vocalized-noise] but if we go for a much bigger size, it willbe of industrial flake[ vocalized-noise ]. So, your container for doing all these reactionswill definitely be the crucible[ vocalized-noise ]. So, this particular case we can have two differenttwo types of crucibles we can have with a concentric orifice. So, you can have a crucible type of structurethat will see in our next class that what sort of these particular crucibles we canhave[ vocalized-noise ]. But the thing is that in the molten requirement, because you can set the temperature high-flown[ vocalized-noise] for those working crucibles. So, the material within this crucible willbe in the molten statu,[ vocalized-noise] and formerly you allow it to pass through someorifice. So, you can have the concentric orifice throughone “il be going” that special core glass textile, and on the outside will allow to pass thecorresponding cladding glass textile[ vocalized-noise ]. At the bottom of that special crucible, so crucibles are not having no outside channel at the bottom, but it will have the passagefrom the bottom[ vocalized-noise ]. And when it is transferred, it is then coolingand the coldnes thing of this fiber is giving you the correlating preparation of thisoptical fiber[ vocalized-noise ]. So, it is coming out as a thread out of this. So, one strand “ve come” at the core threadcovered with the cladding glass and which will be coming out at the bottom of that particularcrucible[ vocalized-noise ]. So, next day in our next class will considerthe corresponding design of that special crucible and how we utilize these things aretwo moltens situations within two concentric crucibles can be implemented[ vocalized-noise] for acquiring of this particular type of optical fiber ok.Thank you very much ..