Recent content by ireland01

  1. I

    Is it possible to see newton rings in CT (xray) images?

    I have seen what looks like newtons rings interference pattern in transverse CT images of 2 solid water block on top of each other. My understanding is that newtons rings occur in visible light eg photography or scanners. Can anyone shed some light on this? :)
  2. I

    Calculation of peak acoustic intensity (in water)

    If we know the max. pressure (p) is 2.5 MPa and T = 20 C. Peak intensity, I = p^2 / rho * c where rho = density of water: 0.9982E03 kg/m^3 and c = speed of sound in water: 1482.3 m/s at 20 C I = (2.5E06 [Pa])^2 / 1.4796E06 [kg/m^2/s] = 4.2241E06 W/m^2 Is this correct?
  3. I

    Bayesian stats: how to update probability?

    I am trying to use Bayesian methods (Bayes rule) to predict further datapoints (at point n,n+1,n+2 etc..)... I begin by generating a normal pdf using previous 75 datapoints (prior: n-75 to n-1) with mean value, μ: 1.25 and standard deviation, δ: 3.67. Note: previous datapoints range from...
  4. I

    Thickness of lead required for 200 keV x-rays?

    I found that factor online.It said to get intensity to < 1% but by my calculations, for 200 KeV beam using formula: HVL = 0.693/u need 7 HVL layers to get to 0.8% which is 4.48 mm. where u = 10.15 cm^-1
  5. I

    Thickness of lead required for 200 keV x-rays?

    is this correct? mass attenuation coeff. = 8.636 cm^2/g 8.636 * (density of lead: 11.3 g/cm^3) = 975.868 per cm thickness (mm): t= 9.21 / 975.868 = 0.009 cm = 0.09 mm
  6. I

    Can following trigonometric equation be simplified:

    yes. thanks. corrected above.
  7. I

    Can following trigonometric equation be simplified:

    yeah. thats it. thanks.
  8. I

    Can following trigonometric equation be simplified:

    Yes. I mean variables are arbitrary. I just want to know if the left side of the eqn can be simplified at all.
  9. I

    Can following trigonometric equation be simplified:

    Fx = sin [ 90 - theta ] * [ dX - [tan (theta) * dY ] ] ??
  10. I

    Electron in magnetic field equation

    equation for radius of curvature of relativistic electron in magnetic field? is this correct: R = gamma * m * v / e * B where gamma is lorentz factor, m is electron mass, v is velocity, e is electron charge and B is magnetic field strength.
  11. I

    What ACTUALLY causes a magnetic field to be generated when there is a current?

    Here's a question for you: Why is there SOMETHING and not NOTHING? Think about it!
  12. I

    Box Muller transform

    Can i use box muller transform to generate a distribution with two different sigma (i.e. sigma_x and sigma_y)? I want to generate a random gaussian angle (C) relative to z axis on circle plane, then set the angle relative to the x, A and y axis, B, wrt to the original angle. However, I want...
  13. I

    Help understanding the Del operator

    del is partial differentiation operator in x/y/z. It's for 3 dimension.
  14. I

    How to rewrite 2D Gaussian eqn in terms of x?

    yes sorry i mean solve for x let f(x,y) = y = 2. say
  15. I

    How to rewrite 2D Gaussian eqn in terms of x?

    http://upload.wikimedia.org/math/1/9/8/1983171154842b0b061fc42aa5eb7642.png" [Broken] How to rewrite this 2D Gaussian eqn in terms of x? i need to calculate the x and y values. let x0=0 and y0=0. is it complex?
Top