Welcome to course on advanced geotechnical engineering, in the yesterday's lecture we have introduced ourselves to different modeling techniques in geotechnical engineering and we narrow down to a technique which is called as physical modeling or geotechnical physical modeling. This lecture is a continuation of geotechnical physical modeling topic. So this comes under module 7 lecture 2 on geotechnical physical modeling. So yesterday we have discussed that if a physical model can be model at full scale then we did not have to worry about the scale factors or scaling relationships. But if the model is not constructed at one is to one scale then we need to have some idea about the way in which we should extrapolate the observations. That means if you look from the material behavior point of view linear and homogeneous for the loads applied in the model if the material is linear or if the material behavior is linear and homogeneous for the loads applied in the model then details of the model can be predicted to prototype without much of you know worries. That means that still with the help of dimension analysis we can do that. But if the material behavior is non-linear or if the geotechnical structure has several materials which interact with each other then it requires understanding about more into dimension analysis and similitude relationships between parameters influencing model and prototype. So this dimension analysis basically it is a method for reducing elements of the form of a theoretical relationship from consideration of the variables and parameters that make up the relationship. The dimension analysis is now a method for reducing the relationship among variables which are influencing a particular phenomenon and these variables can be you know dependent variables and independent variables and dependent variable is the one where which grants the entire phenomenon and independent variables are the one which influences the phenomenon. So if any change in the independent variable then there is an influence on the independent variable. So dimension analysis of a problem leads to a reduction in the number of variables that must be studied in order to understand the problem. So by doing dimension analysis we will be able to lead to a reduction in the number of variables that must be studied in order to understand the problem. So the governing dimensionally homogeneous equation have to be deduced among the key variables influencing the special phenomenon. So for this purpose we have two methods. One is Rayleigh's method or we also call as method of product of powers. The other one is Buckingham's pi theorem. In the Rayleigh's method if you are having say variables like q1, q2, q3, q4, so qn if they are influencing a particular phenomenon by expressing as a method of product of powers and expanding the infinite series of terms and by satisfying the condition of dimensional homogeneity we can prove that the dimension of q1 is to be equal to dimension of q2 to the raise a1, q2 to the raise a2 so on to qn to the raise an. Where in n is nothing but here the number of variables. So by adjusting by writing the indical equations we can actually get the values of a1, a2, a3 so on to an. And by getting these values we will be able to get a relationship among the dependent variable and independent variable. But this method fails if you are actually having more number of variables. Let us say more than 7 variables then this method the operation involves tedious and converting one solution to another solution involves the algebraic adjustments. In such situations the Buckingham's pi theorem is a viable option and where in if you have got let us say q1 to so on to q2, q3 so on to qn then here and r dash and r double dash and r triple dash if there are these dimensionless ratios then we can actually reduce in the term of pi terms as pi1 is a function of pi2 so on to pi3 so on to pin and r dash and r double dash and r triple dash. So here what it implies is that when from the similar procedure we will be able to get this but in order to get the number of dimensionless products what we need to do is that in the Buckingham's pi theorem we have to arrange these variables in such a way that you get the non-singular matrix towards the right hand side of the matrix of the dimensional matrix. Once we solve this dimensional matrix and determine the rank of a matrix then we can actually ascertain the number of pi terms. Let us say the number of variables are say 10 and if you have got say rank of that matrix as 2 then number of dimensionless products possible for that particular phenomenon the consideration is equal to n minus r that is 10 minus 2 8. So after having obtained ascertain the number of pi terms and writing by writing linear algebraic equations and by putting pi1 to pi8 in the matrix of solutions and satisfying those equations which are reduced based on the dimensional matrix coefficients we can actually write get the pi1, pi2 so on to pi8 in the given example. So the Buckingham's pi theorem is used for reducing dimensional products and dimensionless dimensional analysis does not reveal the form of relationship between dimensional products but the correct use of dimensional products make parametric studies more efficient by revealing which variables are truly independent which variables are insignificant and also basis for the also forms the basis for extrapolating from one scale of observation to other scale of observation. So after once we get the pi terms let us say we have got say set of 5 pi terms so our similarity between model and prototype what we say is that the particular phenomenon which actually has been modeled is influenced by pi1, pi2, pi3, pi4, pi5 this implies that pi1 is a function of pi2, pi3, pi4, pi5 for similarity between model and prototype if you are actually not modeling at one is to one scale then for one is to n model small scale model for pi1 to be equal to model and prototype that is pi1 in model to be equal to pi1 in prototype we have to satisfy pi5 in model is equal to pi5 in prototype, pi4 in model is equal to pi4 in prototype so on up to pi2 in model equal to pi2 in prototype. If you are not able to achieve the complete similarity in satisfying all the pi terms then we say that the partial similarity is achieved then we need to investigate that particular effect of not modeling not satisfying this particular this thing have to be verified by experimental investigations. So let us take an example of buried flexible conduit so this is a example of a geotechnical structure which deforms under the conditions of plane strain. So plane strain in the sense that if a long body is subjected to transverse loading and it is cross section and loading do not vary significantly in the longitudinal direction a small thickness in the loaded area can be treated as subjected to plane strain. So here in this particular slide what we are seeing is a underground conduit having diameter D and H is the embedded depth and EI by B is nothing but flexural rigidity of this conduit per unit width that per B units of widths and gamma is nothing but the unit weight of the soil and ES is nothing but the soil stiffness or elastic modulus of the soil and P by B is the line load which is at a certain distance if it is at this particular point it is right on top of that and P by B is at a certain distance and X and Y are the coordinates in the X direction and Y direction and perpendicular to this is say is the Z axis. So the plane strain condition when we say that these conditions are satisfied for this type for example like retaining wall or slope of a highway embankment or railway embankment embankment dam or levee section they are examples of plane strain or a strip foundation of a footing of a strip footing of a typical foundation which extending for number of columns in one line and these are all examples of plane strain. So epsilon Z is equal to the shear strain in Z direction shear strain in ZX direction shear strain in Y Z direction will be equal to 0 that means that the strain in this direction that is ZX plane and YZ plane will be 0 and similarly the shear stress in YZ direction shear stress in the ZX direction will be 0. So only it will have in XY direction and deformations and as well as the strains will be there in these directions. So this particular structure is an example of plane strain structure so what we see is that the load P by B which actually causes in a bending moment per unit width let us say. So depending upon the loading the bending moment per unit width will per B unit width will increase or decrease. So let us say that an important parameter would be bending moment per unit width that is M by B resulting in the wall of the conduit due to construction procedures and surface traffic loading. So the example of say line load what we have considered is let us say a boundary wall and or a railway track the structural property that will influence the bending will again be a flexural rigidity per unit width that is EI by B. So in addition moments will be influenced by diameter D that is internal diameter H that is embedded depth of a conduit gamma that is the density surrounding the conduit and P by B that is the loading which is applied. So the interaction between the conduit and the soil will be influenced by the stiffness of the soil that is ES at a typical depth H that is the interaction between the conduit and the soil will be influenced by the stiffness of the soil ES at a typical depth. So what we have got is that bending moment that is M by B and we have parameters like EI by B it is a conduit parameter and loading parameters are nothing but P by B and again conduit parameter D and soil parameters are H that is the embedded depth and that is the geometry configuration and gamma is nothing but the unit width of soil and ES is nothing but the stiffness of the soil. So by solving by using the Buckingham's pi theorem and by writing dimensional matrix by influencing the variables and the solving the matrix of writing the matrix of solutions we get M by B gamma DQ is equal to a function of H by D P by B by gamma HD EI by B ESDQ P by B D square by EI by B. So if you look into this this particular arrangement has been made such a way that we can lead to some important discussion by using this problem. There can be different arrangements are possible depending upon the type of repeating variables which we have chosen but one solution to other solutions can be transformed by doing the algebraic adjustments for the pi terms because if you are having a pi 1, pi 2, pi 3, pi 4 influencing the phenomenon if these are pi terms which are say dimensionless if pi 1 is pi term pi 1 by pi 3 is also dimensionless. So depending upon the requirement without changing the number of pi terms which are used originally we can transform and get the new pi terms of choice. If you are having a particular variable and if that variable needs to be more than say if it is appearing in more than three pi terms if that variable needs to be eliminated can be eliminated by doing the adjustments what has been said but it has to be seen that the first pi term or the principal pi term used only once. So m by b by gamma d cube which is function of this thing so here there are stress and stiffness related quantities in the loading spread over the cross section of the conduit p by bd and the stress in the ground at the mid height for example here this is gamma h represents the vertical stress in the ground at the mid height of this thing and here this is the conduit stiffness and soil stiffness you know you can see that the conduit stiffness and soil stiffness are related here and so the flexural rigidity a by b and corresponding soil stiffness which is actually related. So let us discuss further you know how we can actually reduce you know different relationships. So here further the continuation of the solution for the example for buried flexible conduit now what we do is that we have said is that when you have got set of pi terms and by for similarity you know so and so pi term let us say pi 3 in model has to be equal to pi 3 in prototype. So if all these are satisfied then only the primary or principal pi term that is involving bending moment will be satisfied. So with p by b in model divided by gamma hd in model equal to p by b in prototype divided by gamma hd in prototype. So here we can actually get two situations what we said is that if you are not modeling at full scale you know then if you at one is to one that p by b in model is equal to gamma hd in model both are same you know in model and prototype are same. But when you are actually modeling at a scale different than one is to one that is say small scale model one is to n. Let us say the environment what we have is that same soil is used as that in the prototype with that we can say that gamma m is equal to gamma p by with for gamma m is equal to gamma p and one is to n small scale model what we get is that p by b in model to p by b in prototype is equal to one by n square. So that is nothing but what we have done is that by bringing this term here and bringing this term there gamma m and gamma p one hm by hp is equal to one by n dm by dp is equal to one by n by substituting that in this we get p by b in model divided by p by b prototype is equal to one by n square. So m suffix indicates model and p indicates prototype which is nothing but one by n square. Let us assume that we have got a situation where gamma m is equal to n gamma p is possible that means that there is a let us say there is a requirement which actually has come and we are able to in a physical model we are able to enhance the unit weight of the soil by n times. So that means that if you are having you know 20 kilo Newton per meter cube of a soil at by enhanced with enhanced n we get gamma m is equal to 20n and for n one is to n scale model we get by substituting in a similar way with gamma m by gamma p is equal to n we get p by b in model is equal to p by b in prototype is equal to one by n. So we can see that if you are having gamma m is equal to n gamma p we are actually getting p by b in model by p by b in prototype as one by n. Now with p by considering another pi term so what we do is that once after having obtained the line load scale factor in model in prototype with gamma m is equal to gamma p for a one is to n small scale model gamma m is equal to n gamma p for one is to n scale model by considering another pi term which actually has got p by b and e i by b terms by using this particular pi term and this relationship and for gamma m is equal to gamma p and d mm by d p is equal to one by n and we have deduced in the previous slide p by b in model is equal to p is equal to one by n square times p by b in prototype by substituting this we get e i by b in model by e i b in prototype is one by n to the power of 4. So please note that this is one by n to the power of 4 that means that whatever we are having you know the value of flexural rigidity per b widths will be one by n to the power of 4 that of in the one by n to the power of 4 times of that. So that means that if you are having a a by p p value which has to be one by n to the power of 4 times smaller similarly with gamma m is equal to n gamma p and d m by d p is equal to one by n and p m p by b in model by p by b in p is equal to one by n this is one by n with that we will be able to get a by b in model is equal to one by n cube times e i by b in prototype. So now we have understood that the flexural rigidity with p by b in model by p by b in prototype is equal to one by n with that we will be able to get this particular scale factor. Now what we do is that by using this you know term which involve flexural rigidity and flexural this soil stiffness term e i by b in model divided by e s d cube in model is equal to a b b prototype by e s d cube by prototype by with gamma m is equal to gamma p and d m by d p is equal to one by n and e i b in model by a by b in prototype is equal to one by n to power of 4 if you put this in the substitute in this what we get is that with gamma m is equal to gamma p and a small scale model and with the deduction what we reduce to here for e i by b scale factor for one is to n scale model with gamma m is equal to gamma p we get the soil stiffness in model is one by n times smaller than the soil stiffness in the prototype whereas when you have a gamma m is equal to n gamma p environment with d m by d p is equal to one by n we can actually get e i by b in model by a by b in prototype as one by n cube and by using this we get the soil stiffness in model prototype is equal to one. So this actually has got you know very high strong relevance that means that in in modeling a particular prototype behavior if you are actually having a simulation of a identical stiffness as that in the prototype the response of a particular structure for example in this case a buried flexible conduit in model so this implies that if you are actually having an environment like gamma m is equal to n gamma p and even for a small scale model we can actually maintain you know the same stiffness as that in the prototype. If you are actually having the same stiffness as that in the prototype that implies that the identical stress strain behavior of a you know in the prototype can be captured very well in a model which is actually tested in a small scale model which is reduced by one is to n tested at gamma m is equal to n gamma p. So this is very important as far as you know the physical model geotechnical physical modeling particularly with gamma m is equal to n gamma p consideration point of view. So let us now consider an example like slope in cohesive soil and assume that we actually have got a saturated clay under undrained conditions so it actually has got undrained conditions and gamma as the unit weight of the soil and d is the depth below the base that is the base layer depth and h is the height of the slope and beta is the slope inclination. So if you look into it the stability of a slope it actually depends upon the parameters like Cu, gamma, beta, h and d. So when you list of the variables we actually have got factor of safety is a function of h that is nothing but the slope height beta that is the slope inclination Cu undrained cohesion gamma and d. So by again by using this can be done by using Rayleigh's method or by using Buckingham's Pytheism and while writing dimensional matrix if you are having terms like this we can actually use force and length approach that means that force is expressed as mLt-2 the dimensions of force mLt-2 and L as L and the stress is nothing but f by L square and unit weight is nothing but f by L cube and by using this we will get two algebraic equations and by solving them and by writing matrix of solutions we can actually get relationship among the variables now here 1, 2, 3, 4, 5, 6, 6 variables are there and we get the rank of the matrix of the dimensional matrix will be 2 so 6-4 so 1, 2, 3, 4 pi terms. So in this out of these two are already dimensionless terms one is factor of safety another one is beta that is the angle or slope inclination. So here what it actually says is that the factor of safety is a function of beta d by h and c by gamma h e. Now from the similarity point of view what we say is that factor of safety for factor of safety in model and prototype to be same if at all we are modeling this particular situation of a slope in cohesive soil for factor of safety in model and prototype to be same what we say or what we have to do is that beta in model and prototype to be same that means that the slope inclination model and prototype to be same and d by h that is the ratio between the d that is the depth below the you know toe of the slope to the height of the slope d by h ratio in model and prototype to be same. If you are and then c by gamma h in model and prototype will be same if all these pi terms are same in model and prototype for a one is two n scale model then we can say that the factor of safety in model and prototype will be same. So if at all you know let us see by looking into the you know the different combinations we say that how this is actually possible. Now one thing we can actually look is that according to Taylor's 1948 theory the Taylor actually has given for slope inclination greater than 53 degrees we can say that it is independent of d by h factor depth factor then we can write factor of safety is equal to function of c u by gamma h and beta. So here the number of variables that need to be considered only two it implies that it is required to maintain the same margin of safety in model and prototype not only the geometry but also c u by gamma z should be so constant. So this implies that for similarity between model and prototype for a we actually have to you know for maintain the same margin of safety in model prototype not only the geometry that is the sloping inclination but also c u by gamma h should be constant. The c u by gamma h should be constant means how that is possible means let us say that we actually have constructed a small scale model h is reduced by h by n. If you look into it somehow let us say that the sloping inclination is achieved then the c u by gamma h in model and prototype to be constant what it implies is that for a slope which is reduced by one by n times the c u by gamma h to be same what it says that the term to be same the c u by gamma has to be reduced by one by n times. If that is reduced by one by n times then only it is possible that you know it will be able to make the similarity possible. So if you look into this if the g can be you know one of the alternatives if you see that you know by reducing the cohesion in this particular term for similar to be achieved what we can say is that by maintaining identical unit weight as that in prototype like gamma m is equal to gamma p and the c u in model and prototype let us say that it is reduced by one by n times then we can actually say by maintaining identical gamma in model and prototype we can reduce c u in the model and prototype one by n times that means that the cohesion of a soil is reduced by one by n times that in the prototype if you are able to do that when you reduce you know h by n and c u by n then they get cancelled then possibility that they will be same. But you know by you know this is you know topic to be discussed the stress strain behavior of a soil which is actually having a cohesion of one by n times the cohesion of that in the prototype and actual cohesion of say c u the both you know the stress strain behavior is drastically different for this can be explained through an example let us consider that in a prototype we are actually having a 50 kilo Pascal's of cohesion and we are actually trying to reduce this by say five times that means that a cohesion of a soil in the model is 10 kilo Pascal's. So the stress strain behavior of a soil under undrained conditions for you know yielding a 10 kilo Pascal's of cohesion and 50 kilo Pascal's of cohesion is different. So this implies that the change in soil behavior which says that this implies that the change in soil behavior and the response of a model will not be you know as similar as that in the prototype. So the change in soil behavior cannot be you know accepted but one thing you know in the in this particular you know approach the scaling down of CA implies that the change in soil behavior. But another option is that we have discussed in buried conduit example is that making gamma n times that means that the soil the self weight of the soil n times heavier that means that gamma m is equal to n gamma p and the maintaining identical cohesion as that in the prototype. If we are able to achieve a situation wherein gamma m is equal to n gamma p and Cu is identical in model under undrained. Even with that also what we are saying is that the Cu by gamma term is 1 by n times that of the Cu by gamma term is reduced. So with that we can actually say that Cu by gamma h in model prototype will be satisfied in that situation what is actually we are doing is that if you are not able to reduce the cohesion for satisfying the similarity point of view then another option another viable option it appears to be as that by enhancing the unit weight of the soil gamma m is equal to n gamma p with that we can actually maintain Cu by gamma h in model prototype identical. So this is explained in this particular slide. So what we said is that for a small scale model if h is reduced and gamma remains unchanged the strength of the soil must be reduced in the same proportion. So this implies that what we are actually discussing the change in soil behavior. Another option what we actually said is that the enhancing gamma, gamma is nothing but if you define this term gamma unit weight of the soil as rho into g where rho is nothing but the mass density let us say in this case of soil mass density of the soil and g is nothing but acceleration due to gravity. So rho which is mass density is a function of packing of particles for a soil or is a basic property of a metal and g can be changed from one celestial body to another body. By using this particular concept and assuming that you know the variation of g is possible we have examples like on the moon acceleration due to lunar gravity is about 20% of the acceleration due to gravity at the surface of the earth. Similarly the Jupiter g on the Jupiter planet is 33% more than the earth. So with that allied thinking we say that this gamma m is equal to n gamma p is possible where gamma is equal to rho into g where by maintaining identical mass density as that in the prototype that is rho m is equal to rho p and gm is actually say increased by n times we can say that gm is equal to ngp with that gamma model and prototype the scale factor for unit weight gamma m is equal to n gamma p is possible that means they provided the g sustained g is actually induced to the model which is in this example a slope in a cohesive soil it makes actually possible for us to achieve that gamma m is equal to n gamma p condition. With that what we said is that the dimensionless term Cu by gamma h in model and prototype will be identical without changing the soil properties. So that means that when you are actually having you know if any parameter which is actually influence in the model and prototype this you know it is governed by a relationship called rm, rm is nothing but physical quantity in model, rp is nothing but the physical quantity in prototype, lambda is the proportionality constant. So the relationship so the physical quantity can be time, velocity, acceleration or force or it can be stress, it can be strain so it is established by you know the relationship need to be established for each and every variable so that for a similitude to achieve between model and prototype which is not scaled which is not tested at 1 is to 1. Now let us consider another example which is you know let us say circular footing on sand. So if you look into this we have got a footing of diameter D resting on the sand having you know dry sand and gamma is the unit weight of the sand and E is the void ratio and phi is the angle of inter particle friction between sand grains that is the angle of internal friction is pi, sigma c is nothing but inter particle cohesion between the sand grains. Then the sand grains interact with each other at the inter particle cohesion generated between the sand grains is indicated by sigma c, sigma g is nothing but the crushing strength of the grain material that means that depending upon the composition of the grain they have different crushing strengths. So sigma g is nothing but the crushing strength of the grain material similarly depending upon the type of grain material we have different modulus of elasticities so E g is nothing but the modulus of elasticity of grains. Now by taking sigma c, sigma g and E g as the material properties of the you know the grains which are actually involved we can and then D g is nothing but the average particle size. So now if you look into it if you are actually having a situation of modeling this at 1 is to 1 scale and by for a given value of delta by D we and by using Buckingham we can get P by gamma D is equal to function of E phi sigma c by gamma D sigma g by gamma D E g by gamma D and D g by D. So here this is the particle size and this is a particle size to the diameter and E g by gamma D and that is nothing but the you know modulus of elasticity and unit weight of the soil multiplied by D diameter of the footing similarly we have got this terms like this. Now for P by gamma D to be model and prototype to be same what it says is that D g by D in model to be equal to D g by D in prototype similarly this pi term has to be same in model and prototype and this pi term has to be same in model and prototype and this pi term that is sigma c by gamma D in model to be same in prototype and friction angle in model to be prototype and void ratio the particular arrangement to be same in model and prototype. Now we can actually say that if you are modeling the situation in 1 is to 1 and all these pi terms will be identical. But if you are having a 1 is to n model and with gamma m is equal to gamma p condition then what we have is that let us see what will happen when you wanted to compare these pi terms. Let us assume that we are actually could able to achieve brought the same soil and void ratio and friction angle are achieved then E model in prototype and phi model in prototype are same. But being these are material properties and by identical gamma but diameter of the footing is reduced by d by n. So this term is not equal to model sigma c by gamma d model is not equivalent to sigma c by gamma d prototype which is nothing but sigma c divided by gamma d by n. So this is different from you know what we are actually need to be obtained. Then similarly sigma g by gamma d similarly E g by gamma d similarly d g by d. So if you look into is for similarity if you look in the deviation 1, 2, 3, 4 pi terms are deviating from the similarity that means that we are actually having very weak similarity as far as similarity is considered with gamma m is equal to gamma p for 1 is to n scale model. So in a similar situation let us say that by you know enhancing the gravity if you are able to impose a condition for this similar problem gamma m is equal to n gamma p. If you are able to do gamma m is equal to n gamma p for a small scale physical model which is 1 is to n is reduced by 1 by n times then what we can see is that again with the same assumption of so with sigma c sigma g and E g as material properties we can say that gamma is increased by n times and d is decreased by 1 by n times sigma c divided by n gamma divided by d by n. So they get cancelled sigma c by gamma d in model and prototype will be identical and sigma g by gamma d in model and prototype will be identical similarly E g by gamma d in model and prototype will be equivalent. But here we are going with an assumption that identical soil as that in the prototype that means that the particle sizes are constant and we have reduced in this case also d by n. So here what we have is that 1, 2, 3, 4, 5 pi terms are identical so the strong similarity is achieved except one pi term that is dg by d by n. In case of gamma m is equal to n gamma p also we are not able to in a capability not able to scale down the particles that lead to an effect what we call and we are going to discuss is called particle size effect. So what we need to do is that how this particle size effect can be eliminated that is what in the dimensionals is if any parameter or any variable or any dimensionals product deviates from the similarity then we have to see by maintaining by satisfying certain conditions how that particular parameter is insignificant in influencing the particular phenomenon let us say for making p by gamma d in model and prototype identical. So with those this discussion we understood that circular footing on sand and slope in coju soil and buried flexible conduit examples what we said is that by for a small scale model which is not tested at 1 is to 1 but which is tested at 1 is to n it implies that gamma m is equal to n gamma p condition fulfills and has actually got the superiority over gamma m is equal to gamma p and 1 is to n scale 1 is to n physical model. Now in order to enhance gamma m is equal to n gamma p there are also some attempts late 1960s by Jelikson. So this was actually introduced based on the total stress is equal to effective stress plus pore water pressure. So if you look into this you know the change in the geostatic stresses with the flow of water to the soils are possible. So introducing the hydraulic gradient symmetry method so here let us consider if water is actually flowing to the soil we know that it exerts drag forces called seepage forces on individual grains of the soil and the presence of seepage forces which causes changes in the direction of flow will cause changes in the pore water pressure and effective stresses in the soil. So by using this concept Jelikson 1969 has come out with a method called hydraulic gradient symmetry method which actually has got you know as a possibility that gamma m can be maintained as n gamma p by doing that what actually we get is that the stress and the stress strain behavior of the soil can be maintained identical as that in the prototype. So let us consider the two cases the case one is that you know hydrostatic condition when no flow takes place in this particular condition as there is no head of loss that is delta h is equal to 0 because the no flow condition then we actually have this is called hydrostatic condition where you have got you know this is the total stress and this is the pore water pressure and this is the effective stress where effective stress is nothing but gamma dash h at this particular point and this particular point it is 0. So here also in this level it is 0 and then it is 0 at this point and then here at this point the ordinate is gamma dash h so no flow head loss delta h is equal to 0 and no change in the effective stress. So this is you know the case one case two you consider where this limb is actually brought down by h and if you look into this here because of this the water flows from you know downward direction. So the water flow is actually shown here in this case and h w is the height of water column and h is the thickness of the soil sample. So we can actually write the total stress as you know nothing but sigma which is here the total stress and the depth here we can write gamma w h w and gamma w h w plus gamma sat h but here what we can actually write is that this is gamma w h w because water flows from this point to this point there is a head loss which actually takes place the pore water pressure drops by gamma if the no flow condition what we have got is gamma w is equal to h w plus h.  Now by taking total stress by computing for effective stress that is total stress minus pore water pressure what we get is that gamma dash h plus h gamma w. So at this particular point we can actually write gamma dash h plus h gamma w and where the h is nothing but the head drop that is over a length h. So hydraulic gradient which is actually you know if you it will be something like a triangle which is actually having an ordinate h here and over a height of h the slope of that triangle is i, i is nothing but h by h that is small h by capital H. So for h is equal to substituting i times capital H we can write gamma dash h plus i h gamma w. So if you see the downward flow of a water increases effective stress in soil. Similarly in case 3 let us say if this limb is taken upwards then what we see is that effective stress decreases the down so we buy this in the hydraulic gradient symmetry method this particular that increase in the effective stress in the direction of flow is taken as you know as a concept and then this particular method is developed. So further developing on this method so we know that in the hydraulic in the in geotechnical engineering a small scale model test are sometimes used to study the complex nature of soil response and soil structure interaction. But it is well known that now the soil response depends upon the level of effective stress within the soil especially for granular materials. If you look into that for granular materials the soil response depends on the level of effective stress within the soil mass. So granular materials at a given density can at different stress levels behave in either as a contractive or a dilatative behavior. So they can actually have contractive behavior or they come are dilatative behavior. So the small scale model test conducted 1G often fail to reveal or represent the phenomenon that may exist at the prototype stress level. So that is what actually we have discussed it from the problems like buried flexible conduit or from the footing resting on the sand. We actually have said that the small scale model test conducted at 1G often fail to reveal or represent the phenomenon that may exist at the prototype stress levels. To overcome this it is desirable to perform small scale model test at field stress conditions and for that what we said is that gamma m is equal to n gamma p is required. So let us say that if you are actually having at a depth h we are having say unit weight of soil say gamma then the prototype we are having vertical stress at a depth h is total stress is nothing but sigma v is equal to gamma h. Now if the same depth which is actually model in 1 is to n scale model with gamma m is equal to gamma p and hm by hp is equal to 1 by n the stress there is sigma v model is equal to gamma h by n that is 1 by n times smaller than the stress which is actually there in the prototype. Now the same situation when it is say modeled with gamma m is equal to n gamma p or nothing but gamma is equal to rho ng condition with that what we can actually get is that with gamma m is equal to n gamma p and hm by hp is equal to 1 by n we get sigma v in model is equal to that is gamma m that is n gamma p into h by n which is nothing but gamma h. So what we actually say that the stress in model in prototype will be identical if you are actually having you know gamma which is actually n times the gamma in prototype. Now we will see how that is actually simulated by Jelikson. So Jelikson proposed method that employs a high hydraulic gradient within the granular soil to create a high body force and high stress levels approximating the field conditions. So we have discussed that self weight forces and the seepage forces they are treated as body forces and the based on that concept and you know the direction what we actually made sigma dash is equal to gamma dash h plus gamma w h with i is equal to h by h what we have what we can say is that sigma dash is equal to gamma dash h plus i gamma w h. So here with the sigma dash is equal to gamma dash h plus gamma w h and by substituting i is equal to h by h what we can write is that gamma dash h plus i gamma w h by dividing throughout by h we can write sigma dash by h is equal to gamma dash plus i gamma w. If you look into it the effective unit weight sigma dash by h is called as effective unit weight is increased by term i gamma w, i gamma w is nothing but the seepage force magnitude seepage it is increased by the term of which is equivalent to the seepage force magnitude in the direction of the flow. So this equation one implies for a model that is subjected to downward vertical gradient i that the effective unit weight of the soil will be increased by seepage force of the magnitude i gamma w. So this is from the basis what we actually discussed we what we have reduced we said that the sigma dash by h is written as gamma m that is the effective unit weight of the soil which is increased by the seepage force term that is i gamma w. Now by writing sigma dash by h is equal to gamma m is equal to gamma dash i gamma plus i gamma w and now we can write the unit weight scale factor and hydraulic or hydraulic gradient scale factor as gamma m by gamma p, this is gamma p. So gamma p is equal to total or submerged unit weight of the soil depending upon the ground water conditions of the prototype. So gamma p is nothing but the total or submerged unit weight of the soil depending upon the ground water conditions in the prototype and for saturated condition it can be gamma p is equal to gamma dash p. So from scaling laws the model will simulate a prototype structure scale n is to n where bm by bb is equal to 1 by n. Also from scaling laws we can say that the model will simulate a prototype structure scale n is equal to n where bm by bb is equal to 1 by n. When a 1 by n scale model test is performed under hydraulic gradient scale factor or unit weight scale factor n capital n is equal to small n the stress due to self weight of soils at homologous points of model prototype will be same. So when a 1 by n scale model test is performed under hydraulic gradient scale factor or unit weight scale factor capital n is equal to small n the stress due to self weight of soils at homologous points of model and prototype will be same. So that means that sigma v in model is equal to gamma m z m where when we substitute the gamma m that is the effective unit weight of soil as gamma dash plus i gamma w z m we can write as by using gamma m by gamma p is equal to n we can write that n gamma p into z p b n there is nothing but sigma v in model is equal to sigma v in prototype. So if the same soil is tested in the model as well as in the prototype and the same stress path is followed the strain in the model prototype will be expected to be same that is epsilon m by epsilon p is equal to 1 while the displacements of the prototype will be larger than the model by a factor n is equal to capital n. So with that what actually implies is that by maintaining a hydraulic gradient which is you know by higher with differential pressures between top and bottom of the soil we can actually ensure that identical stresses as that in the prototype. So in this slide we can actually see that a model with a soil sample of height l m say 0.3 meter is subjected to water pressure difference of say delta p is equal to 300 kilo Pascal's p t is the pressure on the top of the soil p b is the pressure on the bottom of the soil so p t minus p b delta p is equal to 300 kilo Pascal's.  So what we can write i is equal to 1 plus h by l m and we can write for h delta p by gamma w that is the differential pressure by gamma w is the weight of water into multiplied by l m is nothing but the length of the sample. So we can get that i is equal to 1 plus 300 divided by 10 into 0.3 where gamma w is equal to 10 kilo per meter cube and it is 101 that i hydraulic gradient is about 101 with gamma w is equal to 10 kilo per meter cube and gamma p is equal to gamma saturated is say 20 kilo per meter cube we can write and we can get n as 10 plus 101 into 10 divided by 20 with that we will be able to get 50 scale factor that is implies that if these conditions are maintained if the differential pressure of p t minus p b as 300 kilo Pascal's is maintained for a with gamma m is equal to gamma p is equal to 20 kilo per meter cube we can say that l p is equal to 50 into 0.3 that is 15 meters of the length of the soil which is actually represented in the field. So this is interesting technique wherein this is possible and similarly when with gamma p is equal to gamma dash is equal to 10 kilo per meter cube with n is equal to gamma p is equal to gamma dash that is with 10 kilo per meter cube under submerged unit weight conditions it actually says that it is 100 is equal to 100 that means it is about 50 meters. So but the relation n is equal to gamma m by gamma p if you write that gamma dash plus i gamma w in model gamma dash plus i gamma w in prototype for all practical purposes gamma w is equal to gamma dash that is you know the submerged unit weight and unit weight of water we are most identical and i is equal to 0 in the prototype then in that case we can write n is equal to 1 plus i is equal to 1 plus delta p by l m into gamma w. So this is the expression what we actually use for reducing the hydraulic gradient method. So in the hydraulic gradient similitude method which can be applied for granular soils particularly here you know the conditions are that you know where we can actually do the applications like testing of footings on sand and particularly testing of footings on sand with either concentric loads or eccentric loads or recently it has been applied for testing of piles in calculating the uplift capacity of pile in the soil embedded in sandy soil saturated soil profile where in you know so here one of the demerits is that you know the control of this particular you know delta p differential pressure need to be maintained and second thing that the surface has to be horizontal under those conditions this possible that if you are able to do then it actually simulates and satisfies the condition that gamma m is equal to n gamma p and identical stress in model prototype can be achieved. So the applications involved you know can be applied for piles in embedded in sandy soils or footings resting on sand or anchors embedded in sand particularly to the vertical or inclined pullout. So these are the possible applications of this technique and this technique actually has got merits and demerits in its application. So this you know technique with this particular limitations not extended further but the technique what we have discussed is that by manipulating the changing the G that enhancing the G and reducing for a small scale model and thus that technique what we have defined or what we have named as the centrifuge physical modeling centrifuge based in physical modeling. So the centrifuge based in physical modeling technique evolved as very powerful tool for geotechnical engineers for understanding the geotechnical behavior of structures. So centrifuge based physical modeling technique is a physical modeling technique in which a small scale model that is reduced by one is to n subjected to a rotation about a vertical axis in a horizontal plane. By doing this then identical stresses in model prototype can be maintained by with that the stress fields can be maintained as those in the prototype. This actually is possible to understand and you know the behavior of the number of geotechnical structures.


Here's going to be David Scheidermeyer, who is a specialist in palliative care and practices at the FEDA Care Palliative Care Program in Nina, Wisconsin. David maintains a compassionate doctor-patient relationship as a focus, and he champions effective teamwork and collaborative care. He's the author of Putting the Soul Back in Medicine, Reflection on Compassion and Ethics. And a couple of years ago, he gave what I thought was one of the most brilliant presentations we've ever heard at one of the McLean talks, where he combined narrative and storytelling, patient stories, poetry and music. And I think judging by the setup here, we're going to see something of that type of ilk here. And so David's going to talk about the Jack of Hearts. Thank you so much. Mark asked me to delve into this Dylan in the Jack of Hearts. I spoke the first verse for you using this blues riff backing, Muddy Waters type backing. Instead of the original sing-songy chords and melody, that's because I suspect Dylan didn't like the... He's saying this song only once in concert. Just for comparison, he's sung positively four-screet over a thousand times in concert. And no wonder with this stunning chord. But I'm not saying Dylan didn't like the words of the Jack of Hearts song, or that the song isn't important to him. I think it's one of his most important songs. He authorized two screenplays based on the story, but neither came to light. In fact, I think this song is the key to understanding Dylan's fascination with loving and leaving. But I admit that I'm going to tell you a bit of a shaky dog story. Suppose we started the Fox Valley Humane Association where, just to stay sane, my dad and I volunteer every Friday afternoon. Our job is matchmaking. We show our dogs and cats to potential adopters. Many of our animals are strayed, but most are surrendered. Over the years, we've learned that people have all kinds of reasons. No time is the most important and common reason, no time. Can't afford allergies, didn't get along with the other animals. When they're moved, can't take the dog, owner is sick, can't take care of the animal. And our policy, of course, is just to take the animal in and say, thank you. For the stray animals, of course, we have to think of a new name.  Only someone like Bob Dylan.  And here's where the story gets interesting. Dylan gave Hamlet as a gift to bass player Rick Danko and the band when he was recording with him at their house in Woodstock. But Hamlet was no gift. Bob didn't give him to the band. He had to get rid of him. Bob surrendered him. Bob left him. According to Barney Hoskins, who chronicles Dylan and the band in his book, Small Town Tales, Hamlet and Bob weren't getting along too well. He writes that Danko told him, I pulled up to Bob's one day.   He writes that Danko asked, so the truth is, like the people who bring their dogs into our shelter, Bob had to part with his dog for both of their sakes. If he would have brought Hamlet into our shelter, maybe he would have told us, no time for the animal. And thankfully, like most of the dogs in our shelter, Hamlet actually had a happy ending. His new life with Danko and the band was reportedly a good one. He's in their best publicity photos. And it's obvious that he liked wearing top hats. In fact, he fit right into the dress style of Rockabilly 1967. And speaking of former ankle biters, I remember a shelter dog named Solo, a long-haired Chihuahua, and particularly a nasty little dude. When we passed by his kennel, he curled his teeth, and he growled. He kind of bared his lip. He was unadoptable, a ferocious little junkyard dog. Imagine the coincidence when I found that that Solo was my palliative care patient's dog. The man was dying of cirrhosis, and he had to surrender Solo a week or two earlier. The man's mother came into the shelter to adopt Solo. She was then reconciled to her son, whom she hadn't seen in years, so they asked her to bring Solo up to see him in the hospital. My patient was ecstatic to see that his mother had adopted his dog. Solo was a perfect little gentleman up in the hospital, surprising all of us. And then the next day, Solo died. The man never knew it. He died the same day, too. They were both knocking on heaven's door at the same time. What's special about our work in ethics, consultation, and palliative care is also what's special. You can't judge the heart of a person or a dog or cat by how they look, not the veins save. It's said they got off with quite a haul, darkness by the riverbed, it was back in town, but it couldn't go no further. The Jack of Hearts is not only the head of a bank robbing gang, he's a callous lover. At the shelter, the adopter, who is like the Jack of Hearts, is someone without the time for compassion or connection. The Jack of Hearts wants a pet who will please him or her right now. A perfect animal, a pet who will accept being left alone and lonely. A pet which won't need any help or extra love. I remember a funeral home director who wanted a dog. As he said, just to make my funeral home look homey. Not a bad idea, really, because Lord knows funeral homes lack that homey feeling. My dad and I brought him a dog with a crooked tail, which is just about as homey as it is. And, you know, it just wouldn't do. And it was a lovely dog, really. The nicest in the kennel. The kind of smart and gentle dog we see only once or twice a year. He left without a dog. The Jack of Hearts in Dylan's song leaves town without making any permanent connections. Two women, of course, Lily and Rosemary, a fallen corn, and Rosemary kills Jack, Jack's rival, who's called the King of Diamonds. Rosemary kills the King of Diamonds for him, and she hangs.  But, you know, he leaves Lily lonely. Lily was empty now, a sign set closed for repairs. Lily had already taken all the dye out of her hair. She was thinking about her father, who she very rarely saw, and she was thinking about Rosemary. So when he wrote this song, Dylan had already left Joan Baez, and then he left his wife, and he was living with his young Mr. Son in 88-year farm in Minnesota. He then left her as well. Much was going wrong. Talk about me, tangled up in glue. I said, I really don't blame him for surrendering, handling that. I only bring up this shaky dog story, because it's the key to understanding Lily, Rosemary, and the key to the song, and perhaps to Dylan's love life at the time, is to recognize what a drag it was to be Dylan's dog back then. It's a simple and complicated as well. He didn't bond with them. He left them, and he also left them. Now, Hamlet wasn't perfect either, but you show me a perfect dog, and I'll show you a perfect person. I've learned from working at the shelter that you don't love them and leave them. I want to talk to a perfect person or a perfect dog. You know, when you're family, you accept and deal with imperfections. You adapt. You keep. You're surprised by joy. Dylan, who's a true team of both lyrics and chords, well-deserving of the Nobel Prize, understands that this is the central tension of all of our lives, this accepting, dealing, staying versus dreaming, losing, leaving. He knows that for all of us, every evening's empire has returned into sand, vanished from our hands, left us blindly here to stand. Oh, and just one more thing.  My advice would be, most often, once you get them home, you let them pee on this nice patch of grass instead of the concrete at the shelter.  In other words, you show him that you love him, like really loved the Jack of Hearts. Well, you know, you'll find that a dog like him, like he's not so shaggy after all. And just maybe in the jingle-jangle of the next morning that I'm biting you in the ankle, maybe he'll come following you. This is a cigar box guitar that I made. Speaking of which, at the party, tonight we could sure use somebody that would play the piano a little bit for us and guitar if anybody has those skills, please come on down. So this is, it costs only a couple, maybe 20, 30 bucks to make you get yourself a cigar box and this is a hinge. These are doggie bones. My dog likes it. These are strings and my cat likes it. You know, you get what you pay for. Or do you, you know, cats are free at our shelter. And they are priceless to the person that loves them. Any questions or? How much do dogs cost? Dogs, we prorate them on how old they are. So I always adopt old dogs because as a palliative care doc I don't mind seeing them put to sleep. So I've adopted a 12-year-old that was, I think 80 bucks. The puppies we can get about 350 for. Kittens are also, I think they're 125. You get money for kittens, but not cats. I so appreciated this morning's, the early morning's talks and you know, there's a certain resonance of it, I don't mean to compare, but with the animals there's a certain resonance also. With feeding them we have, we too have a food drive at the shelter. Yes. Oh, sorry. Yes. No, what's, you know, this is a three string and I will reveal that I built one for Mark. And you know, if you start, I started with the one string. If you play the air guitar, you start with one. So Mark, I got a one string for you and we're gonna work you up. But three strings that's tuned GDG, so it's the resonance and. We're full deal, yeah. They actually need six strings, too.


I would like to introduce Sidney as the idea was to have to be a talk in his department which is potentially Sidney's old original department. He was, I was telling you, the first full-time member of the class, effectively the founder of the department. He came here in 1943, which is nice. And stayed on his head of the department and saw Sidney. And then I put somebody who was a member of the department on question, took over from 1952. And so, 1952. Yes, well done. Then he did, dealt with, took over from 1992 until 1999. He took his own qualities and he couldn't come and see the change in the place he had not seen. Then became class progress and I took over from 1999 until then. So it's a great pleasure that we have Sidney here. He's a founding member of the department to give a talk about the history of his work. Thank you. Let's go to talk about the history of the HPA after the matter. Medical physics. I've seen through the eyes of some of you who've been through it. And I'm going to talk about the last 60 years, simply because 60 years ago the HPA was formed. But I shall say a lot about the past 30 years. You know much more about that than I do. I retired in 1978 at the age of 60. Simply getting all five rules up that makes me 85 at the moment. So you know much more about the later part than I do. But the only part I'll be talking about mostly. I've always been interested in history. And now somewhat to my surprise I found myself part of it. So first part myself. I took my London B.S.C. in June 1941. Having already decided on a career in medical physics. Soon after I went to see Professor Maynard of what was then the Royal Cancer Hospital Precious Free. And those days of course the hospitals, almost all of them, had to find their own finance, raise their own money with no NHS. And the more eloquent traffic you had through a hospital more likely would give away funds. So it was the Royal Cancer Hospital Precious Free. Many of them have nothing to offer you, but comment is in those days the hospital physicist was worth his weight in radium. He referred me to Professor Russ at the middle sex who was running a team to enable a physicist to be available to any hospital in London requiring a physicist, but without one because of the war. The business has been imposed through uncracked karma. That's what he professed in Newcastle. That's from the time he would become a lecturer in the medical school. I was appointed to understudy him and take over from him. In those days the work of a hospital physicist was almost entirely concerned with the treatment of cancer. Involving the colouration of x-ray-cellable machines and also the use of radium, which was respected and done because of danger upon it. Generally, radium was then stored in a borehole like that of the little sex that we put across small quantities locally, but especially made as a type of steel container. It's about a foot in diameter and about two feet in height. It has a hole two inches in diameter, right down to the middle. And with a brass container, something like 10-10 metres long, was clipped at the bottom of the screw head with many, many turns to see the term. A type on the key is that wood is arsenal when they were designing it, it makes for a bomb and explodes it, and it just bounce beautifully. So it's likely probably alright as far as radium. It was permissible to use radium clinically in those days only if the patient could be nursed in a relatively secure area, which at that time here was the basement of the private patient's wing. Actually, a bomb exploded in one region of one of London's hospitals and the whole building immediately collapsed on top of it. A long search found one of the two radium containers, no two steel containers, in the rubble. This plate was found with a bomb that could explode close to the second container. We put it blowing it across the courtyard and into the opposite wing and collapsed on top of it. But all radium tubes were undamaged in way of clinical use. Radium had been widely used before the war, namely for interstitial and intra-travetary treatments. To reduce the hazards from bombing, some four grams of radium, I think in London terms, that's come about 150 gigavekarels, as radium bromide leaks the arsenic from the floor to the tunnel, part of an old lime kiln in the Chiltern Downs near Luton. This was then a part, in which the first product used for post-proliferation of radium, the gas radon, could be extracted daily and sent to hospitals all over the country. The gamma radium it is of course exactly the same as the radium we used, but the half time was about four days instead of some 1,600 years. Until December I spent some time each week at the Radon Centre and the rest of the middle sex understudying Frank Farmer. Now Professor Russ, and in one of the fundamentals of the British Experiment Radium Protection Committee in 1921, he became a professor in 1919 by the way. The recommendations of this committee were the first in the world on the subject of radiation protection. Even by 1941, radiation protection was still of minor concern compared with today. There was certainly no legislation or code of practice and few recommendations. In diagnostic radiology it was accepted that any patient would only get excreted very occasionally and then over-receive an open accessible dose of radiation. Then he had to death for a warm up before his next examination. I was asked to mention the radiation received by some such patients. The quickly found that the brightening the high doses received by some. Fairly a few patients, for example, often received doses to the back in pen for grad and the highest I missed was about 300 grads. If the larger you put it off, it is then being carried out without any intensification of the image and also not being carried out digitally quickly. I also found that one particular projection of patients in their pregnancy could result in the dose of the gonad of the fetus reaching tens of grads. I was left by one of three people in Britain who were making such measurements and this began to cause concern over the amount of radiation that could be received by diagnostic excreted patients. During my time at the Little Six where I was working with Frank Farmer he was consistent with his work on electronic instruments and measuring the ionizing radiation. He first contained the electron at the valve for a very long time, the total length of high-inflation glass with a good connection at the end. This is, of course, long holidays of transistors. After this time the conventional method of measuring the strength of radioactive source involved in using this instrument which you may or may not have seen will be electrocuted. We have to be fairly expert in making sure that these are properly prepared and so on. I must say I found much more convenient not to have too much of a gold bead. A gold bead means a glass either covered in graphite and much that you see that in the fetus get much better for measuring where things work. I don't suppose these are used much nowadays, are they? So they still pick up in the degree that the, what is it now, pay levels. So anyway, they just have to be used in those days. The thought was that it was based on the gold electroscope. Well, sorry, it's really different from the electroscope and then the gold leaf views and so on and the ratio from two tubes to give you the ratio of the contents and so on. Other things they need groups, they weren't always. I have no idea how much radiation we received during this course, but it must have been quite substantial. The time taken was appreciable and shielding minimum. During this time, the idea was limited that it might be possible to build an electronic metal detector to assist the search in the room for the metallic carbon bodies. It was longer than all days of transistors and commercial metal detectors and also in the early days we stood ahead with our receivers. Everyone then knew that the movement near the coils of a tuned circuit of a radio receiver could alter the frequency that it caused, the ultimate, yeah, howls. But they were visited to us and they were not free to go. Together with the fact that I played about with this project and decided that it was not likely to be then useful, we published a brief note about it in the long term. In 1942, I saw an article in the region cited by an American surgeon who said how useful such a machine had been in their hospital after the Pearl Harbor attack. I wrote him asking about the incident. He replied convincingly, he had no intention whatsoever letting me know how it worked. A couple of years or so later, the further letter offered one free if you wanted it. He would get a sense of what next time an American bomb was coming across this factory with supplies for war-torn Britain. It usually arrived, but at that time, Frank had moved to Newcastle and I had moved to UCH, so he reckoned that we owned the machine jointly. We were once with one of us and if you ever needed it was sent on the next main line at LNER Express to be collected from the guard personnel. It was good at detecting the harnesses of very poor for non-magnetic metals and useless for anything else like a clasp. I had never seen operations with electronic bodies last for hours, with a metal lock found at the end. With this machine, such operations were then much faster, almost always satisfactory. He had the past in such operation, I witnessed, took 17.5 seconds by the theatre clock from a spinning station to removal. The American machine, and we've got a slide of that, some un-mattled cases. It had a carriage core, as part of the two machines that were located in here, which came right to the end here, and the rubber sheath, this rubber sheath had to cover the whole thing, make it sterile for operation purposes. It was a locator, not really a detector. I've been interested to see recently that commercial metal locator now being used to determine the presence of the carriage core and body. But this was a locator, not just a detector. There was one here at UCH when I left in 1962. I don't know what's happened to it since, but... Good. Thank you again afterwards, John. In 1941, in London, the blitz was coming to an end, but still were there rates almost every night, a lot in that day as well. The big London teaching hospitals were decorated to place it in the home counties, where a safety home for an underused mental hospital had ground sufficiently large for the required walls from the botherers to be installed as prefabricated structures. I visited one during my time as a middle-deck to calibrate the output for the two commercial expectations of the machine being used by a dermatologist for treating skin cancers. In the early days of radio therapy, there have been three units of radiation zones, some of which you may have come across. The threshold had a theme of those. It was one of the very early ones, and the pastile dose was also used in the very early days. Early on, it was very effective because the very effective carbide, of course, had a very pronounced quality dependence. And here is the run for dose, the Argyle dose, the 1920s definition, much more satisfactory. Now, the dermatologist asked me if I'd bought my pastiles. I said no, but I'd bought a victory army to which I had doses in rough news. He said he didn't mind so long as I told the radio about how many pastile doses there were to one Argyle dose. I replied that for the radiation he was using, about 300 arguments to run pastile doses. The range of gamma rays was typically more than 10,000. When I finished, I was packing up, and the radio asked for help. The dermatologist had told her to select the medical students and treat for 1,000 feet of diameter air with the upper arm because there was what I said was going to cause a pattern of the virus. He'd be on the next day and see from the skin redening whether I'd done my calibration properly. The visit to another such hospital was to search for two small radium units. To insert the radium into tissues would be packed into a pattern of tube about 2 millilitres in diameter and up to 10,000 feet of long. She was a gold golder. A superficial intra-privatory application to practice similarity was much shorter and some 5 millimetres in diameter. His patients had a cancer for this, and three small people had inserted some days previously. He was of low intelligence, found the needles irritating and pulled two of the three out. When this was discovered, the staff searched the ward without success and then called for help. I got there to see that I shall never ever see again. The medical superintendent, the hospital administrator and the hospital maintenance put all together searching the patient's face trying yet again to find the missing needles. There were no bagged counters in those days, and the search instruments just known as the clutching pen told me that there was radiation present. He turned out to be from the third needle still in the patient sitting quietly beside his bed. He moved away, no further radiation detected. Half where the floor sweepings would go into the incinerator. This time turned out to be just this working, corrugated iron structure half buried in the ground at the furthest corner of the estate. I can tell the gamma radiation was coming from the snuff for the contact to be waked out. Although there had been a gardener on the estate before the war, he came to help. There was a very, very strong smell. Half an hour had passed while I examined one bundle of the field raked out and found one of the two missing needles. When he figured everything out there was still radiation from the area in the middle of the incinerator. The last last needle was found buried in the earth's floor under an upturned half quarter. Fortunately, the incinerator was slow burning and low temperature and both needles were still intact and ready for further use. In the last few days I had letters from three people from the early days who regrettably were unable to be here called the Ristio Tully from HAL. He told me that for this purpose he used an iron station chamber because the sensitivity of detection was very poor in those days to have a very large iron station chamber the news of standard methods of spin. One hot day in the middle of August 1942 on a Friday afternoon about 4 p.m. a professor was on holiday in the Lake District and I was all of nine months experienced behind me who was the C. Lim member of the staff actually in the department. Perville's Clifford Walker later as Exeter was planning out a research project for the professor on people with good luminescence and illuminating dials with pots. He would all be to a large Victorian house in Hastings which he used to illuminate him taking test samples from all the folk working there. The results were quite crazy. He was then far more redirected than he expected. It turned out that on the Monday the director of the outfit had taken delivery of some 50mg of bacon in a large amount as bromide in HBR solution in a glass cuban made pot. He put it on his personal research he was then called to the phone and then turned out to lunch and so on he was asked the part of him to turn around and said, do you know what happened? Ah, crazy. But it was not on his fence. The first reveal of the dead pot ends. Now this is the middle of a heat wave. He knew of course he found out that he had a case of unaccustomed tidiness. He'd taken the tube out of the dead pot melted looked at it coffee water then he opened the window and put it on the wilting flowers in the garden. That was Monday. Unfortunately there was a thunder storm. This was Friday afternoon. I went to the premises and was very worried about the ground where the radium had been poured. Since in wartime any vacant land had to be used to growing vegetables. So we dug out as much of the soil as we could from there loaded into a garage near by not finished using almost midnight the periodic shaft to put that light out. He was the professor who said we should call him the MDL for those days were the forearms of the NRPB. They came and all the soil that we'd collected and dug out put into the lower tens. A few days later I went to see if all was now well to be approached by one of the staff who took me to a magnificent drawing room. This was the room where she did her loonash. There was a desk on the shelf behind the desk. So this was the room. They also used an easy sort of common room for the folk who had been on the premises. But that's all right. I said no. I'm looking through some old papers. I came across a story dating from 1925. A long or 50 milligram radio tube was found to contain much less from that. It was temporary making but it was found that only about half the number of contents were still there. This tube was one of those which had been filled after the First World War with a range of replaying from limited dials from armaments. It was used to filter this range of replays of the radio tubes needed for hospitals. And it was all done using the soluble radium bromide to facilitate handling. However, the seal on this particular tube was inadequate and there was fluid inside. It appeared that the body fluids of innumerable patients had leaked in and dissolved out some of the radium. It was impossible to present and trace those patients but for all the reasons that in all of the country's hospitals the constant recalls can be kept as insoluble radium sulfate to stop that thing ever happening again. In 1943 Prof. Rasmussen called a meeting of the physicists in the hospital he knew about to discuss setting up an association hospital for physicists at the HPA. Only about 60 of us in the country at the time. In history it was the informal society of people interested in the subject. I'm sorry about this. It's been sort of a professional matter it didn't start clear this time until the NHS was being set up in 1945 and 1948. In those days few of the measuring instruments needed could be purchased and then they had to be made in-house. When I moved to U.C. in 1943 I was a physics department for my first three years for the victory in our meter, the lathe, the solving iron every time radio was used in the operating space. I was required to be there with my shaft, my table, and my slide rule. After the size and position of the growth had been determined I would have given about five minutes to calculate the number of the strength of needles required in distribution and a length of pigment time required to give the described dose as uniformly as possible to the target volume. In doing the x-ray films after it I usually found there had been three ideas one was mine after calculation was finished the second was out of the surgeon asking the surgeon from the dose of what the x-ray shows. There was sometimes a similarity between the three. About 1944 I was asked to measure the radius of the steam by the start of the X-ray department. There were no personal monitors available at all in those days so I had to adopt a gentle film but after recovering it was dead I took the first weeks results and went down and called for Dr. X Ah, Dr. X I had the results of last week's radiation measurements who only got so much?  Unfortunately these films offered a needed target to brokers. Yes, unfortunately these films had it prepared me for this. This was on the relationship to the month of December to a senior registrar who went to his control of the funds on the 1st of January and that would come to trace the audience. When I was at UCA I was required to run the firebomb squad our job was to move any of the articles from the roof down to the road or whatever else when I displayed my page to get them off the roof and the screen for any words before your heart could take hold depending on due service if not The hospital then existed but I think it does now on 5 sites with roads between them for a 15 over 100 is any one part 3 per site We could choose where we slept but to leave the crew on the balcony of an extra wall on the fourth floor underneath the glass roof for a bit of an attack which deepens the sub-basement and leaves the hospital playing water intake What are the bonds that ever got on the hospital while I was on UCA? When did you have to have a drink of any agent, please? You need to go after the wall of the general election at which we were once a party with the church and with the beaters and can adapt you to go to the prime minister and one of the election promises was the national health service He chose as the director of health one under Alan Devon a very strong willed character which led to a lot of apprehension In the following 3 years the intense lobbying and negotiating arrangements were reached that seemed to promise well for the future especially for the medical profession and even more especially for hospital specialists after then as a general rule in the modern pre-hospital there was not one by local authority or other public body consultants were on the way and unpaid for their hospital duties but they were allowed to earn their living by treating private patients and the private patients being and charging fees In the following years that restriction sails the drawn up and agreed preparatory for many groups of health service workers and the victim machinery set up each hospital or group of hospitals that were quite arbitrary I started in 1941 at 200 pounds a year about the end of the work requested at 550 pounds which is indeed and we were able to get knowledge and buy our first house at 1150 pounds I looked for the finance office at one of London's richer hospitals and they spent a third of all their income on advertising for further donations The finance department of the hospital was very much a money raising concern usually they still had a pre-war unit for external gamma ray therapy containing about 6 grams of radium called mostly a radium bomb The treatment head was built with sufficient security and natural radium for the patient under treatment as of all those times the radium was kept in the safe due to the head biotechable tube The bomb entertaining the radium was moved dramatically from safe to head for treatment and then back similarly after treatment the tube was disconnected from the safe every night on the safe spot On Monday morning the tubing was wrongly connected the ring on the end of the flexible tubing being left cross-faded on the fitting in the safe As soon as the fans started the air pressure built up blowing the tubing off to the safe allowing the bobbins to describe a graceful parabola to finish under the sink in the corner for room After planning what we're going to do while they care for this we put it back in the safe and the tubing connected properly this time It was probably in the late 50s when I had a phone call from the sub-optimal visible servant I should say about that no, I'm sorry it comes here again Soon after setting up the NHS the visits took her for fellowship of all waiting in hospitals to supply and then charge off to the vent of whatever region they had It's not too ominous for small-radio needles that it involved this charge for the six gram of our so-called radium on I found out that we could replace this region by cobalt-60 and replace it again every three years for a substantial smaller sum So we got the required cobalt-60 and told the minister to supply we no longer needed their radium this was not well received in private Probably in the late 1950s when I had a phone call from the sub-optimal visible servant we gave the task of compiling a suitable answer to a parliamentary question asked by an MP Essentially the question asked how it was that it's a new dirty so-called nuclear cobalt form for a service property being used in some UK hospitals for the treatment of cancer I've went out of the cobalt and found in the familiar name that these radio-friendly treatments had incorporated cobalt-60 and nothing was ever to do with thermonuclear device incorporated in the case of a cobalt I've been struck to see that MP's face and my answer was red Again, with the war we heard about the atomic bombs used on Japan and took steps to find out what we could about them As I'm after, we heard that the wartime airfield at Harville was being used for experimental work on cobalt crops He soon announced that work was underway to get fleet going about low energy experimental power Further, among other things small quantities of radio-assets for research projects and medical services could be available I'd like to know if this task would give every health to any request for radio-asset for medical or medical research work I went to see Deep and discussed ideas with the staff to react to as a middle of what had been an aircraft hangar in case of an immense wall and roof of concrete So as a ladder, we climbed up and walked around on the top and several people conducting experiments some of pieces of equipment they loaded things down into the corn and pulled the luggage In the late 1940s the government decided that the top brass was for free services needed no hunting about the scientific background of the atomic bomb and a double van of one-beat coal


Hey guys, it's Liam from Tinnitus Treatment. I hope you can hear me properly speaking in this microphone, but I got a fan on me right now. But in this video, I'm going to break down how long does Tinnitus last. And this comes from experience for my own life and the lives of other people, but I've helped completely eradicate their Tinnitus. And before we get started, I just want to show you guys some testimonials of the people who've emailed me and just told me about their stories and how this system is helping them. So just for the sake of keeping this video short in length time, I'm going to put up the testimonials and you can pause them if you want to read them. So let's quickly go through them. Okay, so if you didn't pause it, then you can go back and pause it later. It's absolutely fine. So we're going to talk about, as I said, how long does Tinnitus last? Now, I always stand by the evidence that I've seen and the science behind it that fasting is always the best way to get rid of Tinnitus no matter how you got it, no matter how long your pattern for it, no matter how severe it is, no matter how old you are, no matter what gender you are. But this video is for the guys. So there's one other factor that is very, very important for men to understand. It's not testosterone or anything like that, even though it's somewhat linked and it's really just, it's about stress, okay? So it's about stress. And here's an interesting thing about stress. What do most doctors and people and people online and friends and family and people on YouTube and whatever who have no idea what stress is and have no idea about the chemical reaction of stress or anything like that. And they just feel like they can give advice on it. What do they say is the best way to get rid of stress? What are they going to advocate? Meditation, talk therapy, going for a walk, exercising, nutrition. These are lots of things that I say as well, okay? But you need to understand that you have to solve the actual problem. And what I see a lot is a lot of men, this is about men making excuses to me as to why they can't follow the problem.  Or related to the job or something about leadership, okay? Now, let me just backtrack. I'm not a psychologist. I'm not a therapist. I'm not trained in either of those things.  I can't even probably name 15 to be honest. But here's the thing, when it comes to tonitis, sounding cliche, forget about it, okay? When it comes to tonitis, I know what works and I know what helps people, okay? And you shouldn't be threatened or jealous of that. If you're like, I don't know what to do. I'm just worried about everything. I don't know. Because it took me a long time to figure out too. But here's the thing with men, okay? I'm gonna tell you guys a few stories about how to release the stress of the situations and it has nothing to do with meditation, therapy, supplements, you know, or anything like that, okay? So let's go through a few stories of my own life. Now, actually, if you've seen a story of my entire life which goes through about three hours, you would have known that I went through, excuse me, Thailand, Belizea, no, Thailand, Romania, then Belizea, okay? And I actually recently went back to all those places and now I'm back to my third time in Thailand because I went and visited some friends I made in those places and I just love those countries so much because they're so different. Anyway, so let me tell you a few stories. So when I was in Belizea, Georgia the very first time, I was staying in a rough, rough, rough neighborhood, windows barred, you know, big bolt lock on the door. And so here's the thing, I was in Belizea and there was this cup, there was two guys and a girl and there was one guy, it was like 21, one guy was 30 and one woman was like 45. It was the most random group of people you could ever imagine. And they kept talking and yelling outside my window at each other or something, I don't know what for.  So I went outside and just said, hey guys, sorry, look, can you please be quiet? And they were just like, yeah, yeah, that's fine, we'll be quiet. Go back to my room, five minutes later they start up again. So I just walk outside and said, hey guys, like, would you mind just moving down? They were in the car park right outside, would you move down and just basically stop doing this please? They didn't understand that much English and they were like, go back to your apartment. Like, we'll be quiet, we promise. Okay, go back into my apartment. Third time they said I'll be getting even louder, okay? So walk back outside, close the door, it's freezing, put on my jacket, I've got nothing on under my jacket, jacket and tracky pants and my timberlands.  And this might seem completely extreme to you guys, but let me finish the story.   And then they leave. So that's, at least they leave at that stage. They probably realize that they've, you know, done something they probably shouldn't have done and then they go out and even if they lived in the building.  I've like, got kicked in the hair while I was down. It was pretty bad.  So I just got throttled basically. Anyway, got back into my apartment, basically had a shower to wash the blood off, went back to bed and I felt amazing, okay? And here's the reason why. What would most people do in that situation? They let their fear get the better of them, get the best of them. They let their fear of what could happen get the best of them, okay? And this fear has been put in, and this is specifically for men because I wouldn't expect a woman to go out and fight two guys and a girl and maybe you would but this is, you know, you're probably more likely to get seriously hurt or worse. So anyway, and I felt amazing because you've got to tackle the stress head on, okay? You have to actually see what the problem is and go and solve it. And the second thing is don't be worried about what other people think of you. But here's the thing and here's the thing with that. Like, okay, let me just back back again. So let's imagine I stayed in bed. They probably would have stayed out of the whole night.  It's such, it's so obvious what the right answer is.  I've been in a few fights before but I can take a punch to the face, it's fine. It's not a problem for me. I've taken a few in the face but you know, I would say don't do this, okay? The second thing is I wanna ask you guys a question and it's very important to the men and that's do you care what other people think about you? Just have a think about it for a second.  And here's the interesting thing. The answer is always yes.  We're still running off the brain, the brainstem and the reptilian brain if you will, off of thousands of thousands of years ago where basically social isolation, so social rejection, so doing something wrong or weird that results in you being ostracized and kicked out of the clan of maybe 15 people, you would definitely die. There's no way that you wouldn't die. You wouldn't have any shelter, friends, you know. A group, everyone has a role in a group of 15 people back down in the savannah. Some person takes care of the kids, someone goes and gets the food, someone builds the houses, someone's the shaman back then, whatever they had, their medicine if you will, you can't do all that stuff on your own. Now you can, these days you can do that, but we're still running off those brains. So here's the thing, you might think, well, you know, sometimes I don't care what people think about me. You know, for example, if you might say, well, Jack and Leonardo DiCaprio cares what, you know, some person thinks about him. Well, here's the thing. If somebody, it goes both ways.   But you also gotta think, do you care if people like you? And the thing is you actually can't avoid that feeling of, it's an emotional chemical response, okay? Because the feeling of social rejection, sorry, the part of your brain, the neural pathway of social rejection is wired in with physical pain, okay? And I was speaking to a guy from the UK about this, he's actually located in Singapore at the moment. If you're watching this right now, I'm sorry if I forgot Singapore or Dubai. Sorry, I can't remember. But we're talking about this, and it's very interesting. And that's why guys are worried about talking to pretty girls, because they're worried about something that's not even a problem anymore. And that's the second thing about myself as well. And this is an interesting story too. All of the girls that I've dated in the past, probably five years or so, I've not met them through friends or social dating sites. I don't do that stuff. I meet them from on the street. So if I see a pretty girl, go up and talk to them, and if it goes well, we might meet up later, then later in the week for a coffee. Most men look at that and think about that and go, oh, that's silly, that's ridiculous. You could never do that, girls don't like that. That's the fear happening again. You're not addressing the problem in the moment. This is why people go for the easier path of dating apps and hiding behind this stuff. And this has to do with Tinnitus as well, and I'll explain why in a second. But if you're not addressing the problem in the moment when it arises, so if you see a pretty girl walking down, I don't know, some shopping mall or something and you don't have the balls to go and talk to her, there's a problem there, okay? But it's not your problem. It's a biological problem that's happening because of our ancestry. You need to address that. I'm kind of going on a rant now, but you need to address that problem. And you can't, I see so many guys and so many of my friends who, and here's the thing I'm scared when I talk to girls as well. When I go up and talk to a really gorgeous girl, I'm like, oh my God, okay, I'm gonna do it. I'm gonna do it. Men are all the same. No one is different. No one is unique, okay? We're all the same. And as soon as you can get that out of your head that you're special or you need special treatment or something like that, then you really go steamrolling ahead.  So it's always on our minds. There's not, this isn't some PC talk. It does not pretend it doesn't happen, okay? So why, how does this relate to tinnitus? And I'll tell one more story in a second, but how does it relate to tinnitus, okay? When you get stressed out or you overthink something, okay, you pump up cortisol, okay? And cortisol actually causes an insulin spike, believe it or not, because it's hormonal. Cortisol is hormonal, adrenal glands and insulin is hormonal from the pancreas, beta cells. You don't want insulin. That causes lots of problems in your body. Too much insulin. You can get hyperinsulemia. You can actually get, you can make pre-diabetes worse type two. All sorts of problems, okay? And cortisol effects basically is one of the biggest causes of tinnitus, because it's your fight or flight. It correlates to your fight or flight mechanism, your sympathetic nervous system. But if you would just go and take that action, if you would have that awkward talk with your parents, if you would quit your job, if you would start a business you wanted to start, start a business you wanted to start, ask that girl out, get that tattoo you wanted, get that tattoo removed, start going to the gym, start a weight loss regime for yourself. Fast for two days, like Liam says you should do. Ask for my help, email me and ask for my help. If you do all these things that you're worrying about so much, it's like a cesspool, it's building inside of you. And it doesn't matter what the result is, you still feel good, okay?   And the benefit was they walked away and I got to sleep as well. And I woke up with a hella low pain, but that's not the point. The point is I felt better than if I would have just been by a sook. And I feel like men these days, they're getting, I know this is kind of of tinnitus, but it's very important you understand this. Men these days, they're having their masculinity taken away from them, they're having all sorts of problems happening with them. And no, it doesn't benefit anybody. Women don't like weak men. Weak men don't like themselves, okay? No one's winning. Don't like, go and don't do this, okay? But go get in the fight. Go have an argument with somebody. Don't hurt anyone, okay? But you know, like, I have to say again, don't do this, but I'm just trying to put it out there that you have to deal with the stressful situation in the moment as soon as it arises. Don't let it brew inside of you because you're gonna get stressed out. And that makes tinnitus so bad, okay? So, so, so bad. So I wanna tell you one more story as well. And this relates to men and women, but I'm gonna make a video about women too because I get a lot of women contact me and their situations are so similar. It is uncanny. It is insane.  I can see it every time. So I'm gonna make a video about that. But I'll tell you just one story my friend happened to my friend. He had his parents when he was young. His dad was the money maker and his mom was a stay at home mom and they had two kids and they had a third kid and the kids grew up and the youngest kid was like 12 or something like that. It was like 12, 13, 15, I don't know, something like that. Anyway, so the dad was making the money. What happened was they started to get a bit tight with the cash because they had so many kids, right? Like one boy and two girls and the youngest boy was my friend. And what happened was the dad, wanted the mom to go back to work, but he was too worried about asking her because he was worried that she would get annoyed. Remember that wiring was social rejection widening with physical pain. Makes no sense, right? They're married for God's sake. He didn't ask her for a whole year. And when he finally brought it up to her and said, look, the kids are old enough to like stay at home by themselves after school. Would you be able to get a part-time job just like a, you know, whatever? I don't know. I think she ended up being like a paralegal or something. And when he brought it up to her, she said, yes, like I would love to do that. Like, you know, I know we need more money and I'm just sick of taking care of the kids all the time. So she wanted it too. Most of the time, if the situation calls for something and it just logically calls for it, everybody wants it. But because of that social wiring with physical pain, nobody wants to say it first, okay? You need to be the first person to say it. So if you wanna know more about, this video is about men and how men get stressed and how they can help themselves. I recommend you read a few books. I recommend you read Alpha Male 2.0. Horrible book title, I know, but it's amazing. Go read Alpha Male 2.0. I think it's called The Unchained Man, actually. But read that book, terrible name, read it anyway. And go and read The Male Brain by Luanne Brizendine, who's an actually fantastic author. She wrote The Male Brain and The Female Brain. And also, guys, if you wanna just understand stress and understand a bit more how the world works and how you can do more than just get by and reduce your stress, I recommend that you read lots and lots and lots and lots of books about everything. I read about a book a week at the moment, and I really read it. I take about three hours every day and read a book. I love it. But it might be a bit hard for you because you have tinnitus and it's distracting. Put some music on in the background, just get it done. Okay, so let me just tie this back in with tinnitus, okay? So, excuse me, for those of you guys who have tinnitus, let me explain something. This is my theory and what I'm finding. It's getting proven more and more every day. If you just check the testimonials at the start of this video, okay? So, let's say that you fast, probably, like I tell you guys to do, dry fasting and water fasting, and you add the right chemicals to the water. Let's say you fast and you don't address these issues head on, you'll still get rid of tinnitus by just fasting, but it will take a long time, okay? Now, let's say you address these issues head on and you learn how to get good with women because that's how your brain is designed. You actually, you stop wishing the world was a different way. You start realizing the way it is and start optimizing your lifestyle to make the best use of it and be happy, basically. If you just do that stuff and don't fast, you won't get rid of tinnitus. That's the one I'm finding anyway. You really need to add it all in. And this is the fasting and the diet and everything else, okay? So, I've been doing this for a long, long, long time. Years and years and years. I'm from Melbourne, Australia. I was raised by very, very good parents. They're very supportive out of my friends. We just basically, you're not a sook in Australia, or you just get pounded by life, okay? So, I was doing that, but I still got tinnitus because I wasn't, I didn't have all this in check. I didn't have, my diet was awful. I was drinking coffee all the time. Alcohol, it was eating all day long. I wasn't spending any days not eating. So, that's how this correlates. But doing this properly will combine these and dispute it all up. So, I hope that makes sense. If you have any questions, comment below. I'd love to hear your questions. I'll be doing another, I'll be doing a shorter video next time about the actual what to do, A, B steps per day with tinnitus. But this is just something that's really important. And I will be doing a video for women as well, because that's very, very important, as I said. And it does connect more with women who have had kids, because it's such a common story that I only would ever speak about things that I personally have experienced or I've seen again and again and again, enough to be a pattern that needs to be spoken about, okay? So, this is Liam from Tinnitus Treatment, and I'll talk to you guys soon.