Welcome to the lecture series on advanced geotechnical engineering, we are introducing ourselves to module 4 stress strain relationships and shear strength of soils. So this module 4 and this is the lecture 1 of module 4 on the stress strain relationship and shear strength of soils. And we are going to cover this contents of this module in the following way, first we will introduce ourselves to stress strain and then we will try to understand about the Mohr circles and Mohr circle analysis and how to identify a pole and the principal stress space and the stress paths in PQ space and then we will try to discuss about the Mohr Coulomb failure criteria and its limitations and correlations with PQ space. Then it will be followed by the stress strain behavior, isotropic compression and pressure dependency, confined compression and large stress compression and definition of failure, interlocking concept and its interpretations and drainage conditions. Then we will actually introduce ourselves to different types of the shear test which are actually available to determine the shear strength in the laboratory like we have direct shear test and the triaxial test. And the triaxial behavior we will try to discuss in depth and then the stress state and analysis of unconfined compression, unconsolidated undrained, consolidated undrained and consolidated drained triaxial stress with special conditions and the special test particularly the extension test for tension and you know we will be discuss and thereafter we will try to concentrate on the stress paths in triaxial and octahedral plane, elastic modulus interpretations from the triaxial test and how this can be used further in understanding you know analysis of the geotechnical structures. So we have broadly divided this into the following you know contents where in first we will introduce ourselves to Mohr circles and then we will try to do you know the identification of the pole and principal stress space and stress paths in PQ space and failure criteria we will introduce and then you know we will try to look into all these contents in a you know in a systematic manner. The concept of the stress if you look into it if you take a cylindrical sample and if that if you consider this is the so called plane then the stress is actually is you know nothing but defined as a force by area. So defined as the force so this area is you know is collectively from the grain to grain contacts as well as the void area it is also called as the engineering area we have discussed with this while discussing seepage and you know the permeability. So defined as the force per unit area that is force for the that is the internal resistance per unit area so cannot be measured directly and gives no indications how forces are transmitted to the stress material and the manner of transfer of forces in solid crystalline material is different from point to point contact transfer like materials like in material transfer in materials like soil. So the manner of transfer of forces in solid crystalline material is different from point to point grain contact transfer in materials like soil. Now consider here a simple axial stress which actually has been applied with you know the compressive force F on acting on plane PQ in another figure which is there on the right hand side where in a plane PR which is inclined at an angle theta. Now we can actually divide you know we have said that on plane PQ the stress is nothing but sigma is equal to you know F by A but on plane PR if you look into it we get you know the T is equal to F sin theta that means that you resolve F components into horizontal component as with the vertical component then we get T is equal to F sin theta and then with that we actually get the normal force sigma n theta is equal to n by A by cos theta because A by cos theta is nothing but the area of the plane PR because it is inclined at an angle theta so that if A is that area that plane means PR so A by cos theta. So with that we can write that sigma n theta is equal to F by A cos square theta and tau theta is equal to we can write T cos theta that is the shear force acting on the area A with that we can write you know F by 2A sin 2 theta. So with this we actually have got stresses on the plane PR sigma n theta and tau theta and where in the derivation is worked out like this you know the A theta is nothing but A by cos theta and n is equal to F cos theta and n is equal to F cos theta and T is equal to F sin theta that is the F is resolved with an angle theta in horizontal component and vertical component and therefore sigma n theta is equal to which is nothing but the normal force divided by area area is nothing but A by cos theta n by A by cos theta which is nothing but n is equal to F cos theta if you substitute that we get F cos square theta by A. Similarly and tau theta is equal to T by A by cos theta so T is equal to nothing but F sin theta. So we can write F sin theta cos theta by A and with that we can write F sin 2 theta by 2A because sin 2 theta is equal to 2 sin theta cos theta. So we have written tau theta is equal to F sin 2 theta by 2A. Now you know in order to locate the maximum shear stress and we can actually find out you know the angle of the plane over which this mass you know shear stress is maximum. So that we obtain by differentiating this tau theta with theta d tau theta divided by d theta is equal to 0 for maximum value of tau theta we get d tau theta by d theta is equal to F by A cos theta. Now for equal to 0 F by A cos theta is equal to 0 then cos theta is equal to 0 for theta is equal to 45 degrees or 135 degrees and tau theta maximum is nothing but you know F by 2A. So tau theta will be maximum either at 45 degrees angle or you know homogeneous for homogeneous material there will be another failure plane that is orthogonal to that and that is 45 and then plus 90 is 135. So tau theta max occurs on a plane with 45 degrees inclination with sigma and theta plane. So that maximum shear stress occurs you know on a plane which is inclined at 45 degrees you know that is we obtain by differentiating tau theta and equating it to 0 and then for conditions of with cos theta satisfying the conditions of cos theta is equal to 0 we have got theta is equal to 45 degrees or 135 degrees with that tau theta max is nothing but F by 2A. So this variation of the normal stress sigma n theta and a shear stress tau theta with angle of plane theta in cylindrical test specimen is actually plotted here and this is the normal stress normalized here. So you can see that sigma n theta is maximum at theta is equal to 0, sigma n theta is equal to 1 for this is the normalized value which is equal to 1 and 0 at 90 degrees and again subsequently it is maximum at 180 degrees whereas so this is actually variation for how the sigma n theta varies. So this is obtained based on the equation sigma n theta is equal to F by A cos square theta and this is obtained by using the equation tau theta is equal to F by 2A sin 2 theta wherein tau theta is maximum it occurs when theta is equal to 45 degrees. So you can see that this theta is equal to 45 degrees means the F by 2A that is actually is maximum here this is F by A. So the tau theta is maximum which occurs on a plane with theta is equal to 45 degrees and tau sigma n theta maximum on a plane with theta is equal to 0 degrees. Now let us do a small example for the simple axial stress a cylindrical specimen of rock say having 75 mm in diameter and 150 mm in height is subjected to an axial compressive force of 10 kilo Newton. So we need to find out find the normal stress sigma n theta and the shear stress tau theta on the on a plane inclined at 30 degrees to the radial direction and the maximum value of the shear stress and inclination of the planes on which the shear stress tau theta is equal to one of the tau theta max. So the area is nothing but 75 mm diameter so with that we can actually get the pi r square which is nothing but 4.42 into 10 to the power of minus 3 meter square. So sigma n theta which is given by F cos square theta by A so with this you know we can write F into F means 10 cos square and we have been asked to determine and plane 30 degrees to the radial direction. So F cos square 30 divided by area that is 4.40 into 10 to the power of minus 3 so we get 1696 kilo Pascal's and tau theta is nothing but F by 2A sin 2 theta that is nothing but 10 by you know 2 into 4.42 into 10 to the power of minus 3 into sin 60. So with that 979 kilo Pascal's is the tau theta. But if you look into this the tau theta maximum, tau theta maximum which is nothing but which occurs at 45 degree with if it is horizontal which is 45 degrees or tau theta maximum is equal to F by 2A. So F is nothing but here 10 kilo Newtons divided by 2 into 4.14 to the power of minus 3 which that we have got 1131 kilo Pascal's and then we have been asked to find out the inclination of the plane on which the shear stress tau theta is equal to one half of the tau theta max. So this is you know the inclination of the plane at which actually the shear stress is actually the tau theta max is half of one tau theta maximum. So tau theta maximum which is you know tau theta, so tau theta max by 2 is equal to tau theta max sin 2 theta. So with that we actually get sin 2 theta is equal to 1 by 2 so which is nothing but theta is equal to 15 degrees or 75 degrees, theta is equal to 15 degrees or 75 degrees. This is the you know the 15, this is the inclination 15 degrees or 75 degrees the inclination of the planes on which the shear stress tau theta is equal to one half of the tau theta max. Now let us again consider in order to formulate the Mohr's circle you know consider a body which is subjected to number of forces like which is shown here a body which is having in axis passing through O inclined at an angle alpha and subjected to forces F1, F2 and so on to F6 forces acting on a body and in a 2D plane. So the point of the application of force within a soil mass could be on a particle or a void. So the point of application of the force within a soil mass could be on a particle or in a void. As the void cannot support any stress the stress is nothing but F by A where A is the gross cross sectional area which includes both grain to grain contact as well as voids. So which includes both grain to grain contact as well as voids. So as void cannot actually support any stress the stress is F by A where A is the gross cross sectional area both grain to grain contact as well as voids. So what we do is that these resolution of the forces if you do F1, F2, F3 into normal and shear components of acting on a plane passing through point O at an angle. So the expanded view of an element at O is actually shown here, the point O is here and if you consider you know the expanded view of an element and it actually shows like the element ABC where and AB on plane where the vertical force V is acting and which is nothing but you know if this area is say unit area and this is inclined at alpha then the area of this one is nothing but area is equal to 1 cos alpha, this area is nothing but 1 sin alpha. So 1 sin alpha, 1 cos alpha is the areas of AB and areas of BC and areas of AC is 1. So with that what will happen is that the vertical force is nothing but stress into area and horizontal force is nothing but horizontal stress into area. So the horizontal forces are written here and the stresses are also equivalent stresses are also written here, this is the normal force or normal stress and this is the shear force or shear stress. Now here we need to observe here particularly here in this the sign conventions need to be followed consistently. So the compressive stresses are actually positive because in the majority of the geotechnical engineering the stresses are in compression nature. So because of that the stresses are compressive stresses are positive in nature and the tensile stresses are negative and the positive shear stresses produce counter clockwise couple on the element or clockwise moments about a point outside the element. That means that if you are having a shear force acting like this, this is said to be positive if it is producing a counter clockwise moment about a point outside the element. That means that if it is producing a counter clockwise moment about a point outside the element. So if it is a clockwise moment about a point outside the element then the shear stress is said to be positive. So let us consider that if the shear stress is actually acting in this direction downward direction then in that case it will be negative. So the positive shear stresses produce counter clockwise couple on element and or clockwise moments about a point outside the element. So with this what we do is that we try to resolve the forces in horizontal direction and vertical forces and then we try to obtain the equilibrium conditions and then we try to simplify and see that what is the deduction which we are going to get. So at equilibrium the sum of forces in any direction must be 0. So we resolve in horizontal direction and vertical direction with that sigma fh is equal to 0 where h minus t cos alpha minus n sin alpha. That means that the components have been taken h is this horizontal direction is positive because this direction is positive and minus t cos alpha. So that is this portion has been taken t cos alpha that is this force and then we have n sin alpha that is due to the normal force here on the plane Ac. Now similarly sigma fv is equal to 0 where v minus t sin alpha minus n cos alpha is equal to 0. Now by dividing by the respective areas the stresses on the alpha plane that is the plane Ac are the normal stresses sigma alpha and tau alpha. That means that the stresses are here sigma alpha that is the normal stress on the plane inclined at an angle alpha and tau alpha that is the plane inclined at an angle alpha with the horizontal that is AB. Now the stresses on this alpha plane are the normal stresses sigma alpha and tau alpha.  So this is regarded as a by solving a so then we get sigma alpha is equal to sigma x plus sigma y by 2 plus sigma x minus sigma y by 2 cos 2 alpha and tau alpha is equal to sigma x minus sigma y by 2 sin 2 alpha. So we have got sigma alpha tau alpha stresses with the by knowing the application of the stresses the element is experiencing and on a plane which is inclined at alpha. So now these sigma alpha is equal to sigma x plus sigma y by 2 plus sigma x minus sigma y by 2 cos 2 alpha tau alpha is equal to sigma x minus sigma y by 2 sin 2 alpha. So by squaring and adding we get the equation of a circle. So by squaring the sigma alpha and tau alpha sigma alpha square plus tau alpha square and we get the equation of a circle with a radius sigma n x minus sigma y by 2 and at its center at sigma x plus sigma y by 2, 0. So when a circle is plotted in tau sigma space it is known as the so if we are this is actually the definition where when the circle is plotted in a tau sigma space it is known as the more circle of stress it represents the state of stress at a point in at equilibrium and it applies to any material not just soil and note that the scales are for the tau and sigma have to be same to obtain a circle. So whatever from the reduced derivation we actually have obtained sigma alpha and tau alpha in terms of sigma x and sigma y and alpha and by squaring and adding we actually have got a form of equation which is representing the circle and that circle is having a radius of sigma x minus sigma y by 2, sigma x is the stress applied in the x direction, sigma y is the direction applied in this stress applied in the y direction and with a center at sigma x plus sigma y by 2, 0. So when this circle is plotted on tau sigma space it is known as the more circle of stress. So it represents the state of stress at a point at equilibrium and it applies to any material not just soil. So the most stress circle is also called as two dimensional this is in two dimensional this is graphical representation of stress relationship at equilibrium and they are discovered by Cullman in 1866 and developed in detail by Moore in 1882. So this is the development actually goes back into the solid mechanics and then it is used in soil mechanics. So the stresses are represented in the form of a circle so considering any point P x y on the circle equation of the circle can be written as x minus s whole square plus y square is equal to r square where r is the radius of the circle and x and y are the coordinates of point on the circle and s is the horizontal distance of the center of the circle from the origin. So by getting this you can see that this is the circle where this stress is actually sigma 1 so this magnitude from here to here measured is sigma 1 and this is on the tau 0 space and sigma 2 this is this ordinary sigma 2 and this is the radius of the circle so this is called as the Moore stress circle on tau sigma space. Now this deduction can be obtained like this you know the graphical derivation is that once again we can say that normal stress acting on any plane at an angle theta which is nothing but you know in terms of sigma n theta is equal to we can write like sigma x cos square theta plus tau xy sin 2 theta plus sigma y square sin square theta so and using sin square theta is equal to 1 minus cos 2 theta by 2 cos square theta is equal to 1 plus cos 2 theta by 2 and with that we actually get sigma n theta is equal to sigma x plus sigma y by 2 sigma n theta minus sigma x plus sigma y by 2 is equal to 1 by sigma x minus sigma by cos 2 theta plus tau xy sin 2 theta. So shear stress acting on any plane at an angle theta is given by tau theta is equal to half sigma x minus sigma z sin 2 theta plus tau xy sin 2 theta. So tau theta is equal to half sigma y minus sigma x sin 2 theta plus tau xy cos 2 theta. So squaring and adding the equation so again this is actually one form of you know deriving we already reduce this but this also says that you know the equation which is actually reduced to a form of equation of a circle where sigma n theta minus s whole square plus tau theta square is equal to r square and this represents equation of a circle. So sigma n theta minus s that is you know this one plus tau theta square is equal to r square this is nothing but the radius term. So this is represented in the graphical form like this the graphical form when you interpret you will get the number of you know the unknown parameters can be reduced. So this is the circle with radius r at which with a center on tau sigma plot at point sigma is equal to s and tau is equal to 0 that is s is equal to sigma x plus sigma y by 2 which is also nothing but sigma 1 plus sigma 2 by 2. So because this is sigma 1 and this is sigma 2 so this is also given as sigma 1 plus sigma 2 by 2. Now sigma 1 sigma 2 are the principal stresses as tau is equal to 0 on the x axis. So shear less planes are called principal planes so sigma 1 and sigma 2 are the principal stresses as tau is equal to 0 on the x axis. So sigma y and the sigma z and tau z y tau z are the boundary stresses which helps to plot the circle and sigma n theta and tau theta are the normal and shear stresses on a plane at an angle theta to the sigma z plane and sigma n theta and tau theta can be found on more circle by traveling clockwise around the circle from the stress point to a distance 2 theta at the center of the circle and sigma 1 is at an angle alpha to the plane of sigma z. So these are the angle 2 alpha and this is 2 theta which is actually shown here. Now let us consider for some examples of the more circles for different conditions of the stresses that is biaxial compression, biaxial compression and tension and biaxial pure shear. So here when you consider this one with sigma 1 and sigma 2 both are actually compressive stresses acting on an element and the two dimensional conditions have been selected and the more circle represents in a towards the positive side you can see that they center at this particular point and in case here we have a compressive stress and elongation for the element in the horizontal direction that is the tension in the horizontal direction and here there are no normal stresses only the element is actually subjected to biaxial pure shear the element is actually subjected to shear like as shown here. So in this case the more circle is actually symmetrical about this tau sigma axis. So the biaxial compression these biaxial stresses are represented by a circle which plots in positive sigma space and passing through stress points sigma 1 and sigma 2 and on the tau 0 axis. So the biaxial stresses are represented by a circle which plots in positive sigma space that is the circle is actually plotted in a positive sigma space and with stress point sigma 1 and sigma 2 on the tau 0 axis that is these are the points which are actually acting on the tau 0 that this is the this plane on this tau is equal to 0 is tau 0 axis it is called where the stress here at this point where this meets the you know the sigma axis that is called sigma 1 here and where the circle intercepts this point is sigma 2. The center of the circle is located on the tau 0 axis at the stress point that is sigma 1 plus sigma 2 by 2 and the radius of the circle has a magnitude of sigma 1 minus sigma 2 by 2. So the radius of the circle has a magnitude of nothing but sigma 1 minus sigma 2 by 2 and the maximum stress also is sigma 1 minus sigma 2 by 2. So this is the more circle which is so biaxial compression the more circle will be in the on the tau sigma space it will be on the positive sigma space that is the positive sigma space that is this is actually called as positive sigma space. Then the center is located at the stress point that is sigma 1 plus sigma 2 by 2 so the center is actually located at a stress point sigma 1 plus sigma 3 sigma 2 by 2 and the radius of the circle has the magnitude of sigma 1 minus sigma 2 by 2 which is nothing but so the radius of the circle is nothing but the maximum shear stress ordinate which is nothing but the sigma 1 minus sigma 1 minus sigma 2 by 2 that is this is the maximum shear stress located here in the positive side and negative side. And biaxial compression or tension that means the element is actually subjected to both biaxial compression and tension in this case the stress circle extends into both positive and negative sigma space. So the sigma space which is towards the positive side is called as a positive sigma space and sigma space which is actually towards the negative side is called the negative sigma space similarly tau that is the tau space which is above is called as the positive space and below is called the negative space. The center of the circle is located on the tau 0 axis at stress point sigma 1 plus sigma 2 by 2 and has the radius sigma 1 minus sigma 2 by 2 and this is also the maximum value of the shear stress which occurs at the direction at 45 degrees to the sigma 1 direction and the normal stress is 0 in directions plus or minus theta to the directions of sigma 1 where cos theta cos 2 theta is equal to minus sigma 1 plus sigma 2 divided by sigma 1 minus sigma 2 by sigma 1 minus sigma 2. So cos 2 theta is equal to minus of sigma 1 plus sigma 2 divided by sigma 1 minus sigma 2. So for the biaxial compression and shear you can see that this is the compression and this is the tension no shear forces then in that case the Mohr's circle is actually extends to positive sigma space and then negative sigma space also and the center is sigma 1 plus sigma 2 by 2 and the shear force is sigma, exo shear force is sigma 1 minus sigma 2 by 2 and the radius is nothing but sigma 1 minus sigma 2 by 2 and this also the maximum value of the sigma 1 minus sigma 2 by 2 is also maximum value of the shear stress which occurs at the direction 45 degrees to the sigma 1 direction and the normal stress is 0 in direction plus or minus theta to the direction of sigma 1 where cos theta is equal to minus of sigma 1 plus sigma 2 divided by sigma 1 by sigma 2. And now a case of biaxial pure shear in this case the circle has a radius equal to tau xy which is equal in magnitude to tau yz but opposite in sign the center of the circle is at tau 0 and sigma 0 the principal stresses are sigma 1 sigma 2 are equal in magnitude but opposite in sign and they are equal in magnitude to tau zy, so the directions of sigma 1 sigma 2 are at 45 degrees to the directions of tau zy and tau yz. So the circle is represented like this wherein with that you know you have got sigma 1 the major the sigma 1 here ordinate here and sigma 2 here and this is the shear stress that is tau zy and tau z, tau zy and tau yz is represented like this tau yz and tau zy. So this is in case of the biaxial pure shear. Now consider an example where the stress on a circle and a soil mass shown in the following figure we need to determine the principal stresses using Mohr's circle and the element is actually subjected, so this axis is y axis and this axis is z axis and this plane is AB and this plane is AC, so this plane is horizontal plane and this plane is vertical plane and this is an inclined plane inclined at 45 degrees to plane AB and these are the shear stresses and these are the horizontal stresses. So here it is given as 50 kilo Pascal's in horizontal direction compression and this is also compression 100 kilo Pascal's and this shear is 25 kilo per meter square. So the magnitude of the normal and shear stresses on plane AC is shown in the figure, plane AC we need to determine what are the magnitude of the normal and shear stresses on plane AC which is actually shown in the figure here and the magnitude of the principal stresses using Mohr's circle. So the available information is that sigma y that is the stress acting on the horizontal direction that is the 50 kilo per meter square in the y direction and sigma z 100 kilo per meter square that is the stress in the z direction and then tau yz that is tau yz is 25 kilo per meter square the tau yz which is acting the shear acting on this plane is 25 kilo per meter square. So the step one in constructing the Mohr's circle is that mark a point sigma y tau yz and point q that is sigma z, tau zy on the tau sigma coordinate system. So we have a tau sigma coordinate system and we marked actually in the tau sigma space we marked point p and q. Then in the next step is that join p and q with a straight line then draw the circle. So the draw the circle considering intersecting the point of s axis and line pq that is the point o at the center and the distance op as the radius. So with this what we have got is that we have got a circle now that is the Mohr's circle and this is called as Mohr's circle. Now the principal stresses are nothing but the point where this plane where the shear stress is 0 principal stresses where the plane where is the shear stress is 0 that is where the Mohr's circle cross a sigma axis. So by measuring from the graph we can actually get the sigma 1 as 110.36 kilo Pascal's here and sigma 2 here as the 39.64 kilo Pascal's that is from the measurements of the graph. Now we can actually further find out angle 2 alpha that is 2 times the angle between sigma z plane and major principal plane and major principal plane is inclined at 22.5 degrees to the sigma z plane and minor principal plane is inclined at 1, 1, 2.5 degrees to the sigma z plane. So sigma z plane is nothing but the plane on which sigma z acts. So after this then plane inclined at 35 degrees to the sigma z plane and the stresses on the plane at 35 degrees to sigma z plane is obtained by the point so at this point so we need to get if you look into the problem magnitude of the normal and shear stress on plane AC which is shown in the figure. So this plane is inclined at 35 degrees so the 35 degrees is actually represented here 35 degrees to the sigma z plane and this is actually is 70 degrees. So 35 degrees to sigma z plane when you put that this is the point where we get the sigma n theta that this horizontal ordinate is sigma n theta and vertical ordinate is tau theta. So from the measurements of the graphically we can get sigma n theta is equal to 42.96 kilo Pascal's and tau theta is equal to 14.94 kilo Pascal's. So this how you know what we have got is that from the graphical interpretation we actually have got sigma n theta and tau theta for the type of the stresses which are actually given by using the Mohr's circle concept. Now the three dimensional stresses on a cubical element the elements are actually subjected suppose if you consider an element within the soil it is subjected to the following stresses in x and y and z directions and on each plane there will be one vertical stress and two shear stresses. So you can see that on this xy plane we have vertical stress and you know the shear stress tau xy and the tau zx which is actually acting here and similarly on this plane sigma y and then these are the shear stresses which are actually acting and similarly on this plane and on this plane or the stresses are shown on the visible planes clearly. So these are actually represented in the matrix form like this the three dimensional stress at a point can be represented as t alpha t sigma is equal to sigma x tau xy tau zx tau yz sigma y tau yx and tau xz tau xy and sigma x sigma terms are the normal stresses and tau terms are the shear stresses. So please note that sigma terms are the normal stresses the tau terms are the shear stresses and the total six terms are independent and then we have sigma x sigma y and sigma z tau xy tau yz and tau zx and then if the references axis are in the directions of 1, 2, 3 and which is nothing but the direction of the principal stresses then in the geotechnics we are actually suppose if you are having a cylindrical sample or a let's say cubical sample we have if it is in the major vertical stress direction sigma 1 then it is called sigma 1 as the major principal stress and sigma 2 as the intermediate principal stress and sigma 3 as you know minor principal stress. For a sample which is cylindrical in nature the sample will be having a vertical stress that is sigma 1 major principal stress and 2 the stresses parallel to the acting on the plane that is nothing but sigma 2 intermediate principal stress and minor principal stress and the cylindrical sample as sigma 2 is equal to sigma 3 we generally refer it as sigma major principal stress and minor principal stress that is sigma 1 as the major principal stress and the sigma 3 as the minor principal stress and the sigma 2 as the intermediate principal stress. So the Mohr stress circle particularly in the three dimensional stress conditions is a no simple method exist to draw a Mohr circle to represent the general case all normal and shear stresses acting on all the six phases of a cube. So two simple cases can be represented by using the Mohr circles as given below and one is that a cubical element having only normal stresses on its faces and a cubical element which has only normal stresses acting on pair of opposite faces and both normal and shear stresses on remaining two pairs of faces. So with this slide what we wanted to convey is that no simple method exist to draw a Mohr circle to represent a general case and all normal and shear stresses acting on all the six faces of a cube that means that all normal and shear stresses acting on all six faces of cube cannot be represented and two simple cases can be represented by using three Mohr circles, A which is the case A is the cubical element having only normal stresses and another case which is cubical element which has only normal stresses acting on pair of opposite faces and both normal and shear stresses on the remaining two pairs of faces. So it can be proved that the stress conditions on any plane within the element must fall within the shaded area but it is usually sufficient to be able to determine the stresses on planes which are perpendicular to at least one opposite pair of element boundary faces. So stresses on these planes lie on the circle bounding the shaded area so these stresses for the case A where block which is actually having only normal stresses you can say the sigma 1, sigma 2 and sigma 3 are shown here. So in this case the Mohr circle is actually represented as this is the you know circle and with sigma 1 and sigma 3 and sigma 2 is the intermediate stress that is the intermediate principle stress. So here in this case A it can be proved that the stress conditions on any plane with within the element must fall within the shelled area that is this shelled area and it is usually sufficient to be able to determine the stresses on planes which are perpendicular to at least one opposite pair of element boundary faces. So in case B it is represented where we are having normal stresses and at least two faces are actually having the shear stresses then in that case we draw three Mohr circles here this is the Mohr circle 1 and second and then third one. So now here first you are drawing this Mohr circle and then after knowing this as the major principle stress and this as the minor principle stress sigma 2 and sigma 3 then this is the third Mohr circle and the second Mohr circle as once we have this one and that is the minimum stress that is the third Mohr circle. So in case of case B which depicts a cubical element with compressive normal stresses acting on all six faces and shear stresses on two pairs of opposite faces. So again in this case the stresses on all planes within the element lie within the shelled area and with stresses on all planes which are perpendicular to at least one pair of element faces lying on one of the boundary circles. The sequence of drawing the circles consists of first drawing of locating the stress point sigma z tau z y and sigma y and tau z then drawing the circle that means that first we have to locate this sigma z and tau z y and sigma y and tau y z and drawing the circle one that is the first one is the drawing this circle one locating these two points and then dropping here perpendicular and these are the sigma z axis that is measured from here and this is sigma y. So this drawing this points then drawing the circle through these with the center on the tau 0 axis tau 0 axis so this is the first Mohr circle which is drawn the second one locates this locates the principal stresses sigma 1 sigma 2 so once we draw the circle one we have got the opportunity to identify sigma 1 and sigma 2. Then as the third principal stress is known now the circles 2 and 3 can now be circles 2 and 3 2 and 3 can be 2 and 3 can be that is 2 and then finally the third circle that is the with intermediate principal stress sigma 2 can be drawn. So this locates the principal stresses sigma 1 sigma 2 and as the third principal stress is known the circles 2 and 3 are drawn subsequently. So in this case sigma 1 is greater than sigma 2 and then sigma 3 so as it has been told in geotechnics it is actually convenience to use sigma 1 as the major principal stress sigma 2 as the intermediate principal stress sigma 3 as the minor principal stress. So let us look into a problem where in a piece of sandstone is cut into the shape of a cube with 100 mm long edges and the forces of 5 kilo Newton 10 kilo Newton and 20 kilo Newton are applied respectively uniformly and on normal to the three pairs of the faces of the cube. So a piece of sandstone is cut into the shape of 10 centimeter in size you know having the long edges of the size of the edges 10 centimeters and forces of 5 kilo Newton 10 kilo Newton and 20 kilo Newton are applied uniformly and normal to the three pairs of faces of the cube and evaluate the major intermediate and minor principal stresses in the rock and subsequently draw the more circles of the stress and we need to also find out what is the maximum shear stress in the rock. So by knowing the forces the element is actually subjected then you know we can actually calculate what are the you know what is the maximum shear stress within the rock and what are the major and intermediate and minor principal stresses the element which is the sandstone element or a piece of rock is subjected. Now for this you know what we take is that the area of the each face is A is equal to 0.01 meter square wherein there is nothing but 10 centimeter into 10 centimeter 100 centimeter square in terms of meters it is 0.01 meter square. This three principal stresses major principal stress sigma 1 is equal to 20 into 10 to the power of minus 3 divided by 0.01 that is 2 mega Pascal's and intermediate principal stress which is nothing but sigma 2 which is 10 into 10 to the power of minus 3 divided by 0.01 is 1 mega Pascal and minor principal stress sigma 3 is equal to 5 into 10 to the power of minus 3 divided by 0.01 that is 0.5 mega Pascal's. Now we have got sigma 1, sigma 2 and sigma 3 the stresses this we have calculated based on the sandstone which is with nothing but the force which has been subjected divided by that area of the face of that particular sandstone rock piece and with that we have got these major principal stress as 2 mega Pascal's and intermediate principal stress as 1 mega Pascal's and minor principal stress sigma 3 as 0.5 mega Pascal's and with this what we have got is that now on the tau sigma space where the tau the scale which is actually here is you know on the equal scale with the equal scale when you represent and we can write that on the sigma which is here. So the major principal stress being the sigma with this as sigma 1 and sigma 2 that is intermediate principal stress as 1 mega Pascal's so with 1 by 1 mega Pascal's by 2 that is 0.5 mega Pascal's as radius can draw a circle so with that we get this first circle. Then you know once we get this one then with this as sigma 2 that is 1 mega Pascal's and sigma 3 as 0.5 mega Pascal's so 1 minus 0.5 that is 0.25 mega Pascal's as radius we can draw another circle that is the this one and then one more circle is actually possible that is sigma 1 and that is the major principal stress and minimum principal stress that is 0.5 that means that 1.5 you know mega Pascal's as radius so we have drawn circle 1, circle 2 and then circle 3. So in this we can actually see that the maximum shear stress in the element which is actually subjected which is the radius of the largest Mohr circle so the maximum shear stress is nothing but the radius of the largest Mohr circle. So if you look into this the maximum shear stress which is actually given by this circle is nothing but 0.25 mega Pascal's and here this one is nothing but 0.5 mega Pascal's but however if you look into this circle which is having a 0.75 mega Pascal's as the radius so the maximum shear stress is yielded the element is actually subjected is about 0.75 mega Pascal's so what we have done in this particular problem is that we actually by knowing the forces subjected to the by the this the cubical shape sandstone piece we actually have calculated the what are the stresses acting on the major and intermediate and minor principal stresses and then we have drawn the Mohr circle of stress and then we also find out what is the maximum shear stress in the rock piece. So for this what we have done is that we actually have calculated the stresses with force by area and then we plotted of these stresses on the tau sigma space with drawing 3 Mohr circles where in order to deduce the maximum shear stress here the tau max is actually here indicated and this is the this circle actually yields the you know the maximum shear stress so the sum the for the type of forces which are has been subjected the rock piece actually has been subjected to a shear stress of about 0.75 mega Pascal's. So if we are having say this much shear stress and in order to ever to the failure along that particular plane then you know the material should have adequate shear strength. So the shear strength which is actually you know counters the shear stress which is actually resulted due to the external loading system. So in our further lectures what we try to look into is that how further we discuss about on this concept of this Mohr circles and the how to locate a pole and then how this different element conditions can be used in you know understanding about the stress states in a you know for the elements and then we deduce you know we connect ourselves to you know the stress parts in the PQ space.


Hi everybody it's Sam at Mixed Up Craft, thank you for watching today. So my usual what did I get goes up on a Thursday but the stuff that I had coming didn't come till today. So I am filming it not long after I've got it but I had a little kind of play with some of it and I'm really really happy with what I've got. First of all I want to talk about embossing folders. So I shared my designer handbag tutorial this week and I mentioned in the video that I would love to know if anybody can direct me to a large A4. Embossing folder and the lovely Erin, thank you, she shared this link to me, it's from Crafts2. I will share the link below and this one here was actually really good price as well, it was oh where's my, oh I don't know where my invoice is for that one. Anyway like I said it'd be linked below but it was a good one. I haven't opened it yet. I'll take this one out but if you see closely it's just like the Crafters Companion one which was the studded leather but in the middle of these are little hearts. I mean you could still cover it with a flat bat pearl but I like the little hearts there. Now I wanted a large A4 one because I've got a larger size designer handbag tutorial that I want to do so this one is lovely. So yes I know you will need the larger die cutting machine for these ones but those of you that do have it check out the tutorial that will be coming in the next few weeks because I've got a new series starting next week. Then I picked up this one so this was a Gemini the basket weave. So you can see there and this is just lovely for jumpers and it's going to look nice as well on gift bags. So again I will link them below. Honestly guys I've probably had in excess of 60 emails and messages asking for links to the embossing folders. I can't help when things sell out. I can't help if things aren't even available when I use them in my tutorial. It's just how it goes. I'll try and help as far as I can but I get really frustrated myself when I can't share the links with you guys because I know how much you want to be able to do the tutorials but I try to do tutorials that you can still try and use that you can use your own supplies to make. So don't worry if you can't get that exact padded looking embossing folder. Use something else. People have been sharing on mixed up crafters lovely alternatives. Okay so I put out the inspiration there then go look at your supplies and see what you've got then if you do desperately want the same one I've got then yeah I'll try and help you. So that's the embossing folders then I had a voucher for craft stash so I really loved these stamps. These three sets here are by Creative Stamps. Again all the links will be shared below but this one here I really like and it's the Otterly Fabulous range so I'm going to be making a nice card for that. Then I had this one here which is the sweet sloths really really cute and so nice to colour because they're just completely plain so you can do all your shading and stuff. But my favourite one there we go. Now this one is $3.99 it's bargain but the images are so good nothing like I've got so it's the Fabulous 50s A4 stamp set but the one that I really like is I love the boy eating his cake and I love the rocket I think that's wicked. A burger one is really good but my favourite is her because she is going to work through so many things. I can imagine her on the bottom of gift bag and then loads of flowers across the gift bags it's almost like she's kind of opening up her arms and all these flowers are there or a lovely big sentiment there you know saying welcome home or something I don't know I can just see her the way that she is her expression she can be used on so many different things so I really really like it and she is a great size she's probably about four and a half inches I reckon tall. You've got really nice sayings still an old classic I like that one down there with the old car you've got him there cool dude with his tattoo and his like his cream and his what's the real cream and his comb shake, rattle and roll it's just really really good you've got the steak there as well so love it really can't wait to start using that one. So they've got the stamps there and then I got some more kind of essentials I guess I've got the hook and loop this is the 20 mil these are the ones that I do kind of share a lot in my tutorials I pick these up then I also got another one of the silicon foam tapes I love this this is what I kind of use now all the time when I make shaker cards I've got literally that left of my other roll so I can get one little bit out of it so I've just got another one of those I love it and then I've got the last one to complete my set of daisy made designs stamps and dies and this is the daffodil basket so you know my favorite flowers are daffodils and poppies so I had to get this one you've got the beautiful big die there to cut it out you've got a lovely little label to cut out this here and then you can have thank you with love and I know I've got other little stamps there that say happy birthday so I can use this for many many things I think it would make a lovely little get well card as well and you've also got the extra daffodil head so that you can do a little bit of deco parts you can stamp and cut that one and then stick it on top there and it's just really really pretty do go and check out daisy may is Claire Roland she's the illustrator really lovely lady her her kind of style is just beautiful so sweet so yeah go and find her on facebook because she's got some lovely inspirations there then also on my order I picked up the Nuvo hybrid ink pad now I like to use alcohol markers and I like to use watercolor so I have my memento for my alcohol markers and I've got my Versa fine for my watercolor and I'm pretty good with getting them the right way but there have been times when I picked up the wrong one I've gone to them use color and it's bled the hybrid is all in one so this hybrid here this is the black shadow you can use it with your alcohol markers and you can use it with anything water-based and it's well from what I've seen it's brilliant so I've picked this one up here I've taken out the packaging already but that is what you're going to be seeing seeing me use more it says fast drying all surface ink so yeah I can't wait to use that one so that's the hybrid then I've picked up this here I've seen lots of people using this on the crafters companion demos and it's envelope gum so I don't like to lick envelopes and I you know when we get the pre-made ones I will put a little kind of wet my finger or put like a wet sponge across it when I go to seal it so I would still do that with this but basically it will give you a professional finish on your handmade envelopes so when I make a lot of those larger envelopes with my cards I usually use double-sided tape now I can use this so you apply a thin coat of gum to the envelope flaps and bond together so you don't have to use it straight away either so you can let it dry and it'll be sticky so the only thing I would say it's a shame they don't do it in more of a squeezy kind of tube style like these something like that because oh it smells like a nappy they don't tell you what it smells like on the tv oh yeah it's got a bad smell oh I don't like that okay we'll see how we go with this once dry unbonded flaps can be re-moistened to seal the envelope so the people I've seen use it they just put their finger in there and after smelling this I'm not putting my finger in it so I have got the very thin little spatulas you know like the kids glue spatulas I'm going to use that for this so yeah you'll see it come up in the videos but I always like to share it now so that if anybody isn't is interested you can go grab it so there's loads in there as well they did so that it will last a very long time but yeah keep the lid on because it doesn't smell too nice then this is what I'm really excited about it's not brand new it's called the white fluffy stuff by Cosmic Shimmer and this is what it does it's brilliant now my mum actually had this so she's introduced me to this one but can you see here so this is all textured to look like snow so I want it for my Christmas projects now I'm going to do a little demo so I didn't put too much on there but if you so it just goes out like glue okay so I'm going to put a little bit more on this time there we go all right so you just apply it you can see there then I'm going to grab my heat gun now I'm going to turn the volume off okay and you can just watch it hopefully I pick it up in the camera so I'm just going to get this warmed up hopefully that picked that up but can you see look at that look how raised it is you can see it on the side there there we go that gives you a really good idea this is going to look brilliant about this is going to look really good around like windows just to give you that kind of snow effect around the bottom of the Christmas tree it's really good you have to let it cool down so that's quite warm don't you've got to keep the heat moving and don't hold the heat directly for too long because it will end up kind of browning it which could look good for a different kind of effect so I just I'm really pleased it is drying hard now so I mean I wouldn't want to put that I've want to put that in a protected envelope if it was something I was posting because I imagine it could get flattened but it is you know for when you give it to someone they're going to be able to see yeah it's got quite a funny texture it's like rubbery I think it's brilliant so yeah this is called the white fluffy stuff so you can get I think a larger bottle I believe I'm not sure but yeah really really pleased with that and it has you can see how much that's lifted off it does stay stuck like I'd have to really peel that off okay and then lastly I've picked up these John Next Door dies now they do do matching stamps as well but I thought I'm just going to get the dies first then I can decide if I want to get the stamps so the stamps will give you the detail on top of these flower and kind of vines and things but you can add the detail yourself as well so it's entirely up to you but I thought I'll get the dies because at least that way it's cut out quickly rather than me stamping and then having to cut it out if I was to buy them that way so I wanted this so these are the Christmas collection but you do have this is addition dies this is addition dies so these are the three Christmas collection but they're all part of the Christmas collection I think I'm sure they work they're all listed together but you can use this all year round so this one here I believe is called the Christmas Rose and basically every single one of them is a plate so you only you only have to run it through the ones depending on obviously how many you want to do so you have all your elements here so you have to cut them in different colors so that's really nice you haven't got lots of loose dies but just look at the details so I inked these so I die cut them all on white and then I inked the centers in yellow inked the outer parts in pink and then I done all this in the in the middle there now these also work brilliantly with the thin foam flower sheets I don't have any but I have ordered some because I do want to try these with them because especially the orchid here looks so real in the foam sheets so you have more of a foam ranian I can't even get my words out flower so that's the I believe the Christmas flower you can see the little picture there that's actually using the foam and it's on the top of like a gift box topper and then in the background in white they've used this here which is your ivy and this is I love out of probably all of them take away the poppy because poppy is my favorite but I love this because this is going to work brilliantly on so many different things so I can imagine this on my gift bags kind of coming down from like the handle or something it's going to look really nice now you also get all these extra pieces as well so you can really fill it up but you so that's all die cut from one plate okay and you can see again the inspiration on the picture now the stamp I don't know how well it's picking up can you see all that detail that's what the stamp would do but when you kind of distress these with my my little barbarian tool that I've got it creases the card stock to kind of give a bit of a vine like vein sorry look and then you can distress that as well with things I haven't distressed that that's just as it come and then I've used my like I said that little stylus thing but you can see the flowers there and what a lovely topper that would make on a gift box or on the card front and things like that so that's that one there but they don't give you names exactly of what it is it just there's literally I can't see nothing it's just the code so it's got John next door so jnd and then one three three that's one four four so they obviously do stuff by codes here it doesn't actually tell me like that that's the ivy for example but anyway these will all be linked below so that was that one just touched on that one so I went and just die cut it in white and then I distressed the centers with yellow and then I added with a fine pen there just some little black dots and you get three on that one plate so you can make those three there so again if you just you know you you get a lot of flowers with one pass and considering that was all done on white that's all I had to do I just cut that on white inked it up and I got those very quickly so if you want to double or you know make a really big cluster of something isn't going to take you long to do which is what I liked and yeah the poppy is just beautiful so there is my poppy and you can see there again the inspiration of what they've done they've heavily distressed those they've got the black around the outer part also it's got the stamp on it so again if I bring it up you can see all like the vein detail there so you know have a little look because it's well they look lovely either way so really like it and again there's the plate with all of those on it I like these kind of dies this is crafting to me I like to put things together and kind of bring it to life so some people it might be a bit too detailed then that you know that's fine we've we've all got the different things that we prefer but I do like to bring my dies to life especially this I think that looks really quite real actually when I see it in my monitor that looks like a real piece of ivy so you know you do that in different colors and distress it and stuff you can really bring things to life and you're you're definitely going to be seeing me kind of using these I just think they're going to look brilliant and then lastly I've got this one here now you can I think it says well it says Christmas collection but this can certainly be something that you can use you know all year round well I guess more autumnal but you can certainly add it to different things so again it doesn't say what they are initially I see the helicopter seeds when I when I see this though you know off like a sycamore making the maple tree things like that but I also see and I think that's what they've decorated them like here your mistletoe so this is mistletoe so I've put the three together and then I've used some flatback pearls in the center there and I've put that bow on and I've distressed it and everything but if you were to do this in brown and instead of having the flatback pearls had real dark brown almost nuvo drops it would look like the the kind of dead seeds of the helicopters or you could have the nice fresh ones on the trees still still hanging so I like that I could kind of get a bit about that so this is for mistletoe and I will be using this I'm gonna you know that's ready to go on a card really I think it looks really pretty but you also get the then the little fur cones so there's three there and again you can see the picture the inspiration and on the back there how nice does that look on the card that top is beautiful as well that was another thing that I saw they're really really detailed there's just so much going on with them you can see all the different colors you don't have to have light on top you can have dark on you know light on the bottom and yeah just have fun with it they really really are good and I can't wait to do more with them so you can see on that one there there's the plate and you get all your doubles you get the detail and the background the detail background detail background so that's your kind of three parts or six parts really for the whether you want it to be the helicopters or the mistletoe and then there's all your fur cones so yeah I wanted to get some dyes that we're going to work for Christmas but also work all year round you know all these flower ones the orchid I don't have anything like that and I've got poppy stamps because the lovely Kimmy she sent me that beautiful poppy stamp the other day that one there I don't have a flower dye that's so full and has that detail in the center there are one two three that's four little dyes to build that center up and once you add your inks and do all the distressing and stuff it looks beautiful and I've got lots of other leaf dyes and stuff some of the bright rosa ones are going to go really well with this which actually leads me on to these are my bright rosa edge builder dyes and this one here has the lace edge I mean the honeycomb would look love as well but this ledge one looks like lattice work looks like a you know a really nice kind of fence or something in a garden that I've got an idea to have this ivy kind of growing up the side there you could have it as a shaker card which I think is going to look beautiful you could have a couple of these and can you see already how that lovely card's starting to form so yeah I can't wait to start playing around with all these because I think they're just stunning so there you have it that's what I got this week I can't wait to get crafting and really really looking forward to using these flower dyes a bit more and I can't wait to color these lovely images in and yeah just play around with it also you'll see it you know as always in my tutorials I use everything that I buy it doesn't sit there I have an what I call an inbox and in there goes all my new product and that's what I go to so that's my inspiration so I go to it everything is all mixed up so I can think that I go nice with that and I'm going to add that with that and that's what I like and that's why it's called mixed up craft because I mix everything up so anyway hope you've enjoyed what I've got today all the links as always will be shared below and I'll be back actually I think I am going to throw in a tutorial tomorrow Saturday don't usually but I've got so many banked that I think I can need to get a few out actually so yeah you'll probably see me again tomorrow thanks for watching bye


Hello friends, so after understanding about the various components which can be included in integrated paste management, so another component wherein we are much interested to know that is botanicals in integrated paste management. So in this lecture I am going to cover on these subjects, so first what are botanicals, in brief history of botanicals in paste management, important families which are actually various plants in important family which constitutes the botanicals, then properties of botanical, then classification, then how they are going to act on insect paste. So before that let us see what exactly the botanical insecticides, these are naturally occurring chemicals derived from plants or sometimes even minerals, so sometimes they are also called natural insecticides. From the history perspective these botanicals have been used since many years and there is a record about the use of these botanicals in paste management in important Hindu book that is Rig Veda wherein these plants products were used and likewise even this botanical insecticides were also used in China as early as 1200 BC and in India this our own domestic plant that is Nim which the different parts of Nim that is flowers, fruits, leaves, bark and roots they are actually regarded as Panchamruta by Chara Karushi. So similarly these botanicals have been used extensively during 1700 and 1800 before the invention of synthetic insecticides and among them Tobacco and this Deris that is Rotanine products were largely used for the management of various insect paste across the country including India and this Rotanine was much used and afterwards because of its ill effects on fish and another product that is Sabatilla was used for the management of insect test. Similarly another important botanical that is Pyrithram was first used against insect control in USA during 1858 and another important botanical product that is Nim. So which acts as anti-fidant and looking to its importance so many research have been conducted during early days and one important international symposium was held in Germany during 1980. So let us see which are the families actually they contain principal components of insect sites in plants that is first Malaysia which family consists more than 500 plants which are known to be contain the principal products of insecticides similarly Mitacea, Astracia and so and so forth. So why these botanicals they are very much important in pest management because of they easily break down and thereby there is no residual effects on other non-target insects and some of the botanicals they are fast acting on selective insects similarly they are selective and produce high toxicity to target insects similar to insecticides and they leave least to fight toxicity on plants and another most important in one is they are naturally available and locally available and their cost is less. Based on their physiological activity these botanical insecticides can be grouped into six groups. The first one is repellents since most of the botanicals they act as repellents and among them is one is DEET it is commercially available and used against mosquito flies and other insects and next group is feeding deterrents or they are also referred as antifidents. So the one best known example is azidectin which normally acts as antifident and sometimes even repellents also. Some of the botanicals they do act as toxicants and wherein 100 percent mortality is also possible and some of them is eucalyptus. So this can produce up to 100 percent control in stored grain pest like tribolium confusium and normally these botanicals they are used as natural grain protectants in most of the areas even in India also these botanicals they are much used in management of the stored grain pest. So among them it is most of the custard apple wherein 1 to 2 percent kernel powder or aisle is mixed in management of stored grain pest and similarly some of the botanicals they act as chemosterolants or there is I mean they are going to inhibit reproduction in insects. So that is among them is pyratrum, rottanine and also nicotine they are going to inhibit the production of offspring. Next insect growth and development inhibitors so some of the botanicals they do act as isias that is insect growth regulators among them is the neem which is going to affect most of the leptopterne and colapterne larvae. So this table actually shows the different plants and their scientific name and which family they belong and the principal active component which is present in that plant and also which part of the plant that is being used against the management of insect pests. So one example so citrus wherein the principal active component it is limonene or linole wherein it is obtained from peeling the skin of this citrus fruit that is peel extracts effective against some of the insect pests. So these botanical pests so they are used to control different insect pests and this table shows botanical pestisent that is active component and also against which insects they are effective. So nicotine it is very effective against both the sucking pests and also the chiving insects like caterpillars. Many friends in our next class we will continue this botanicals in pest management wherein we will discuss about the various important botanicals which are available and they are used in pest management and afterwards we will discuss their utilization, drawbacks and other things. Thank you.


22 విటణికిఆఆరువవాచిాసక నదినిండిచి. విటిటటుకికాచిసి మానికానికిసిని. క౿టికికినికి. ధతటరికికిఇతికికి. It is a high responsibility and definitely honourable thing that she admitted mistakes and inability to deliver on the mandate and resigned. This indeed indicates how she valued the nation above her personal interests. Following this trust resignation, Rishi Sunak, a member of the British Parliament and Chancellor of the Echequer, who appeared to be more prepared for the position and has a more realistic plan that captures to this United Kingdom economic reality was later appointed as Prime Minister of the United Kingdom. In fact, Rishi Sunak imagined as the first British Prime Minister of East India, that is Indian descent. The lessons that could be deduced from this event and applied domestically as those. For a government to succeed it must first meet the criteria for good governance and be empathic towards the needs of the people. With the problems facing the country, it is accurate to see poor leadership has brought our current problems on us. For instance, the recent ban by the United Arab Emirates proves that our foreign policies and relations have been disrespected and this is the effect of feud diplomatic relations. Not only that insecurity and natural disasters like flooding top the litany of pestilence that brought about by negligence and poor leadership. Democracy is a government for the people, by the people and it is high time we as with the people take this definition to heart by getting it right at the post next year. Those are the hem of affairs should respect the will of the people. It is important for government to listen to the queries out cries of the masses and strike a balance in decision making. In order to build or rebuild our nation from the bottom up we need to have empathic leaders who understand what true development is and can utilize human capacity for the positive change we need. This leader can be anyone irrespective of their ethno-religious identities. Our ethnic or religious diversity should not be our divider rather it should be our common strength and balance. Any Nigerian irrespective of gender, religion or tribe can aspire and be given a chance where necessary to lead effectively. Let me conclude on this note by quoting John Calvin Maxway an American author, speaker and pastor. A leader can give up just anything except final responsibility political candidates beware. They say everything rises and falls on leadership. Everything does. This is quite interesting because there is nothing more important for Nigerians and Nigerians right now than what is going on. Even maybe a bit more than what we are going through what is more important is where we are going to which is the elections in 2023 and we are where we are so far maybe because of the kind of choices we made the last time but my main concern is I don't see us making choices that are any different. Are you a prophet of doom? You know I remember a long time ago when of 2015, well there about 2016 it was a new year, someone called us on the radio let's talk about what we envisage for the year and a prophet of doom Prophet of doom will say it's going to be this, it's going to be that the thing is when something doesn't go in the way we expect, we think it's doom because someone is trying to say the positive motivation movement is a bit too much so this is what I believe in facing the right truth the real situation while projecting your expectation on it what I am seeing we are projecting too much positivity but what I am seeing but I'm sure an agenda is seeing it it's a dicey situation it doesn't look like we are making any the choices we are making are any different because we are still fighting with a Muslim-Muslim ticket is it a northern Muslim ticket that's what we are, the young people want a young person the whole people are not to say you can't vote a non-Muslim that's what's going on that's the conversation is going on right now you can't vote a non-Muslim you can't vote anyone who is non-Muslim so we are not any different from where we came in 2000 1950 we are not any different so let me get you straight you are not a prophet of doom you are only following the indexes basically I think what he is saying if you think about the decision making matrix there is a decision maker there are people that are involved in making the decision there is a chance to be made and then there is consequences so one of the problems that we have is we don't want to be responsible for our decisions we want to be responsible for the consequences unfortunately unfortunately the only choice you have is decisions that you make you cannot choose the consequences because your decisions would have consequences decisions have consequences so which is beyond your control the control that you have stops a decision making which is what he is saying the fact that we have spent 7 it will be 8 years by next year 7.5 years having made certain decisions have we actually as a people moved away from where we are where we were mentally when we made those decisions now that's one part of it the other part of it decision makers at the time the people that made those decisions at the time are they the same people that made the same decisions at this time because you want to ask yourself they say in sanity the definition of sanity is doing the same thing doing different results now if the same set of people are the people making decisions if the decision making falls on the same parameters and the same indexes you would have the same results so it's not a prophecy it's just indices it's just projections it's just mathematics one plus one will continue to be two until something changes to the second one either it becomes half or it becomes two it's simple mathematics so if people if a certain people make certain decisions every four years you have to change two things either you change the decision making process so they can make a different set of decisions or you change the decision making people completely so they make a different set of decisions so that's what I think he is saying that's what I'm getting from what he's saying so like you said then lessons will be learned from everywhere right well in conclusion I believe very strongly that every nation must find a kind of system of government that works for them I don't believe that one size fits all it's almost like what I said about education you gather 20 people in a room accept them to think the same way accept them to take the same courses to pass the same exams the same system of teaching 20 different people with 20 different brains 20 different orientation 20 different backgrounds 20 different trainings so we create this monovercity versus a multiversity it's not even a university to be honest with you it's a monovercity we need to start creating multiversities that have people get rid of the box and start to think outside the box I don't know what's going to happen but I think that it's going to take us a while it's going to take a certain generation or a certain demography of people to shift from decision making process but I believe that next time around it might be better than what was said hopefully it will be better except if the domino effect some of the things that happen now will still stumble they usually do when you are a gentleman you have spoken very well it's good to know that after all you are not a prophet of doom you mean well but you are following the recent current realities so we will just reflect on this that we don't have you can make excuse for everything but not for responsibility we as citizens the masses when we come out of it let's be responsible for ourselves and our make the right choice and then the candidates and those in government should be responsible for making the right choice on doing the right things they should not do the wrong things and be found wanting because whatever the consequences that happens we don't have control and it could be catastrophic if it's not managed properly so let's take responsibility where necessary siege hasn't is nest after the break just stay with us


Thank you, everyone. So my presentation is about Behive and GPU password. So first of all, let me introduce myself. So my name is Corvin Kürner. I'm a software developer and mainly developing for x86 and developing hypervisor technologies. And I'm working for back-of-automation. And back-of-automation does industrial automation and PC-based control. So back-of-does everything for industrial automation. So starting from panels, PCs, I-R controls, drives. And we also provide software. And we're interested in GPU password because since our founding, we are using Windows as operating system. And we integrate our software into the Windows system. And now we want to move on. And don't use Windows to integrate our software anymore. So we decided to use FubiSD. And now we are integrating the software into FubiSD. But our customers are familiar with Windows and they want Windows on the machines. So we're using the Behive hypervisor to start a Windows VM and gives the user a machine which looks like a Windows machine. But it uses FubiSD with the hypervisor. OK, so move on with the interesting part. I will start with a short live demonstration how this GPU password works. Then I will tell what's new because this presentation is a follow-up of my presentation 2021 and the vendor summit. And at the end, I give some instructions for all of you can test the GPU password. OK, for my live demonstration, I'm using a system with an I-Core 7 PC. So it looks like this device. And yes, I'm using the integrated graphics and pass it to the Windows VM. OK, so let's move on with the live demonstration. OK, so for the live demonstration, I've connected a KVM switch to my device. And so I've also prepared an SSH session to the device. So first of all, we can look at all the PCI devices, so with PCI-CONF. And there we got our VGA device, so our GPUs. And because we also want to control this VM, we also are interested in the USB device, so the XHCI device. So we want to pass through both of these devices. OK, so first of all, we have to load the VMM kernel driver. And if we have done this, we have to make sure that no other device uses our GPU and the USB device. So there's a special driver for it in QubesD, so it's called PPT. So we can use DevCTL to detach the driver from the device. So we're interested in PCI device 2 and 20, so we call DevCTL detach for both devices. And after this, we can use DevCTL to set the PPT driver to both devices, so for device 20 and 2. Yeah, and now we're done, so if we can check PCI-CONF again. So now we see that the GPU and the USB device is connected to the PPT driver. And now we can just start Behive. So we add some flex to the Behive core, spend some cores, some memory. And what we need is, we always need the host bridge. Add slot 0, then we need a disk. So I've prepared the Windows disk. Oops, next. So next we add the GPU, so we can just use it at the password device. And there's some special about this GPU, which I will talk later about. So there's a ROM option. And if you add the ROM option, you can add an expansion ROM to the GPU. And here I'm using the GOP driver. And I'm on this later in my talk. So next we need the USB device, the LPC device, a boot, no, SCDIO, lastly the user local chair. Do you have the camera link or do you have? Oh, sorry. We have been lost. OK, what's missing? Boot from user local chair. Do you have the phone? Oh, this. OK, it's all NUEF. So if you're familiar with Behive, there's no special thing about this. We have called except this ROM, but I will talk about later on this. So now you can see that on my device, the hyper-vital starts up and you immediately get graphical output from the VM. And now the Windows VM starts. Yeah, we know so it's taken a while. So we were in this device, is it weird at the moment? At the moment it's in our country and there we have a small rack. And we have connected the KVM switch to it so that we can see what's happening on the device. Yeah, and if you check the task manager, you will also see that the graphic card is detected by Windows. And there are also some benchmark tools, and now I've installed just one of them to show you that you can even run an accelerated graphics because here you can run different benchmarks, 120. So yeah, DirectX 12 wouldn't work with out-accelerated graphics. So we can just, for example, run this test. And as you can see, the run test starts and it works. So here we can use accelerated graphics. So maybe wait a moment until it really starts. Okay, and there it is. Yeah, it's a bit laggy, but I think it's more issue with the network connection and not the GPU as you saw there was an FPS counter with 400 FPS. Thank you. Okay, so let's continue with the presentation. Yeah, so I've showed you that it works for Windows and I've also tested it for Linux. So for example, here's an Ubuntu VM and there also we can see that we are running in a Behive VM, but the device is detected and also the driver is attached. And yeah, this also works. And the benchmark I've shown you, I've run the complete benchmark and there you can see, yeah, for the 2D benchmark on the left side, there's a Behive VM on the right side is a native system. And if you compare both numbers, you see that you get about 80% of the full GPU performance in the VM. And it's very similar to 3D graphics. So that's even a bit better because you get about 90% of the native GPU performance. Okay, as I mentioned earlier, this is the follow-up of the Windows Summit in 2021. And yeah, the state was that the dedicated AMD graphics, it works on the current branch. Yeah, but integrated graphics don't work. Dedicated in the graphics, I don't know because I never tested them. And so in upstream Behive, with my patches on our system, for example, the integrated Intel GPU works, as you have seen. Okay, so let's start with dedicated AMD graphics cards. So they only require standard PCIe pass-through. But there's an exception for Linux and BSD because the driver there needs the video bios. And yeah, it is part of the PCIe specification, but it wasn't implemented in Behive. But I've added this support. And it's also upstreamed and supported in 30.1. But there's one issue, and that's not Behive related. It's OVMS, so boot room related. Because the video bios is a bit special because the bios have to shadow this video bios. And the operating system searches for the shadow copy. And if OVMS doesn't do it, the guest VM wouldn't find the video bios and can't use it. So yeah, it's supported on the Behive side but not on the guest side, sadly. And yeah, that's the current state for AMD graphics. And for integrated graphics, I don't know what is required. I've tried it and I hadn't success until yet. I've also tried to pass-through it on other hypervisals like QEMO, which often has some more features. But even on QEMO, I wasn't able to pass-through the integrated graphics of my devices. So yeah, I don't know what they're missing. And the next device is the dedicated Intel graphic devices. But as I mentioned earlier, I haven't tested it yet. I don't know if they work or if not. Yeah, we have to see. And the integrated graphics for Intel, they work on Linux and BSD in upstream, but not for Windows. And if you want to know what's missing, the problem is that the integrated graphics have some non-standard PCI resources. And you have to handle them. And yes, the Linux and BSD driver don't care. And I don't know. Maybe they don't use them. But the Linux driver does. So first of all, there's a so-called graphics store memory. And we have to make sure that this memory is allocated and in some way assigned to the device. And there's also the so-called operation. And you also have to allocate and assign it. But you also have to use the host operation because there are some information about the configuration, which should be used for the graphic card. And this has to match with the host configuration otherwise it don't work correctly. And the last one, the last common graphic cards are from Nvidia, those dedicated graphic cards. But I have tried it a bit, but didn't work much on it. So it's still work in progress. OK, so if we look how we continued. So on the vendor summit, only dedicated AMD graphic card works in current. Now they work in 30.0.1. And yeah, this is one exception for Linux and that the guest doesn't work. And the integrated graphic card works for Linux and BSD. OK. So now let's move on how to test this by your own. And I would start with the GodDriver, which I mentioned in my live demonstration.  Then the UEFI tries to find and start the bootloader. And the bootloader tries to find and boot the final operating system. And yeah, this could take up some time. And yeah, all of you know that on normal systems, you can enter your BIOS and modify settings and so on. And responsible for this graphical output is the so-called GodDriver. And so at some point in the UEFI stage, the GodDriver gets started. And it's responsible for graphical output. And then at one time, when the OS starts, the operating system driver will continue. So it is not required to use the GodDriver. But yeah, if you want to get graphical output while you're in the boot stage, you have to use it. So and of course, now the question is how you get the GodDriver. And for AMD and Nvidia, they are dedicated graphic cards. So they have to ship the GodDriver with their video BIOS, which is somewhere on the cards. So there are some ways to dump this video BIOS. But for integrated Intel graphics, there's no really common way. And even Intel with their own Acron hypervisor say that you have to ask your board manufacturer for the GodDriver. Yeah. But for AMD and Intel, so I'm not aware of any method to dump it on FubiSD. But for example, on Linux, they can use this FS to dump the video BIOS on Windows. There's a tool called GPUsZ. And there you have an option to save the video BIOS to a file. And yeah, but maybe it's a bit harder to dump it with it. And there are also some video BIOS files online. And you have to take care that you use the same version, because if there's a mismatch between the version you're using on the host system and the guest system, yeah, I haven't tried it. But I can imagine that it can get you into trouble. And yeah, to add it, it's relatively simple. I've did it in the demonstration. You're just at the ROM option. And yeah, append the pass to your GodDriver. OK, so let's start with specific instructions for the different kinds of graphic cards. So if you want to test GPU pass-through with AMD cards, yeah, just use your pass-through option like you do with any other device. So maybe one hint there, because while you need the operating system driver to get, if you don't use the GodDriver, if you want to install a VM, so on Windows, there's mostly no driver.  Or yeah, if you have a VM, you can set up a remote desktop so that you can remotely connect to the VM. And then attach the graphic card and install the graphic cards driver. OK, but yeah, so on Linux and DSD, it doesn't work it on upstream. So you have to do some patches to the OVMF. And on back off, we have a GitHub repository. And there we have an EDK2 talk. And yeah, I have a branch which is called FabCorp and K. And then the release date of the EDK2. And you can use this branch to build your own OVMF, which works for GPU pass-through. Or I also have an open patch on Fabricator. And there is also a binary file, so you don't have to compile the OVMF by your own. You can just download it. And then, yeah, you have to attach your own modified OVMF to the boot ROM option. And of course, yeah, you have to append the ROM option to your pass-through line. OK, and the steps for integrated integrated graphics are very similar, so you also have to use the patched OVMF. But you also have to rebuild Behive. And then you also have the option to either use my Fabricator patch, or you can use our GitHub repository and get the same Behive version, which I'm using. But there are some things you take care of, if you want to start CVM into CPUs. So first of all, you have to use the ICPI tables, which are built from Behive. Because normally, if you run a boot from, they are used from the EDK2, but they don't match. So yeah, the Windows driver won't be able to use the GPU device. And you also have to take care of the slot of the way to attach the GPU, because it's an integrated GPU, and Intel always attached it at slot 2. So there are many drivers, which they all, the integrated graphics is always on slot 2, and they don't check for any other devices. And there are also some issues on Windows, if you don't use slot 31 for the APC device. And lastly, you have to use the boot room. So things like Behive load or grab to Behive won't work. Yeah, this GPU pass through. OK, and yeah, of course, it's not required, but if you want POS output, you have to attach the GOP driver. Yeah, the Intel and BSD side is a bit easier, because you can just, like you normally do, attach the Intel GPU pass through the device. And this also works on Upstreet. And yeah, so as a short summary, if you want to test these, all these things, you can take, first of all, take a look at my fabricator patch. Then you can also check our guitar repository from back off. And yeah, from 3BSD and ADK2. And if you have some questions, you can also mail me. OK, so thank you all for your attention. If you have any questions, just grab a picture of us, people. There is a vegan version available if you need this. But if not, I'm sure there's lots of questions, but I'm here, so I'm going to ask my first, what's blocking this landing? Like what do we need to do to get it into the video? Yeah, so it's a complicated topic and it's also a bigger patch. And yeah, and so it's a bit more complicated to merge all of this stuff. And also, I think on QEMU, the whole GPU pass through with integrated Intel devices is a bit complicated because they don't like to merge some of the patches because Intel does something a bit strange because it's an integrated GPU. So it's always there. And so you can include some drivers in the BIOS instead of providing a good video BIOS for the integrated and so on. And so it's a bit hard. I thought even the Linux community don't want to merge some of those patches. OK. Is there any other? Yes. I guess to talk, I feel it's amazing that you start with the demo of the landing. Thank you. Thank you very much. Thank you. Yeah? So for the two, it is important because, yeah, as I mentioned, some driver use the slot two for the Intel GPU. So it's a fixed value and they don't scan the whole PCI bus. But for the 20, it is not important. It was just a choice from my side. Yeah. Maybe I can take a step back here. So here I'm marked. I don't know if you see that this is green, the two. Yeah, so this 31 is important. And this two is important to work properly in Windows VMs. Yeah, I'm not sure. So I'm always using slot two to don't have any issues. So I don't test it much. I know that the God driver has problems if it isn't attached to two. I don't know if the operating system driver has problems. Yeah, but I always attach it just to two and then I don't have any problems. Yeah? How are your users connecting to those workstations? Are they physically less connected to the experience or is it to VMC? Well, you mean how I managed to see the live demonstration? No, I think we mean how I use those. The end users that are using it is their Windows workstations How do they access it? They have a show on there or VMC or is it that physical thing?  Yeah. And then you go to the first slide. They show our devices. They cannot be seen. No, something like that. And on the left side, this is a penalty scene. And this is the use case for our GPU pass through to sell this device to a customer. Run BST on it for our win time, OK? And give the display output from Windows and the pass through the GPU. So it is passed through to the Windows machine. And so actually the end user will access the Windows in the background there, so I can get running the time stuff. OK. Thank you. But the need for this is automated. Yeah, you can just sample this drone and drone as an attribute option. And there you can just say, add reboot. Run this behave command. So if your machine boots up, you see for a short moment the previously screen, and then the VM starts up, and you get your VM screen. Yes? Can you switch back to the previous ones, the previous ones? So like, you turn on the Windows and you get the relighted back to the previous ones? Not yet. But this is not a problem of behave. This is a problem of the Intel driver, because if you attach the Intel GPU driver, everything is fine. If you detach it, everything is fine. If you attach it a second time, the system crashes. And the problem is normally you boot up a boot up, you have your Intel driver, then you detach it to use it for your Behive VM.  And I've also talked to someone who is working on the DMK mod port, and he's also aware of this issue, but there's no solution yet. Before the Intel driver? So I'm not sure what the problem is. I once take a look in the core DOM and it looks like there was an issue with the driver naming because the Intel driver tries to attach a driver a second time with the same name, and then it crashes. And yeah. Yes, because there's our signature child device, it's probably doing it twice here, so we need to attach it. Great, thank you very much. Pull it. Thank you.