Section Definition and 733 Threads

  1. chengmo

    How to use mdata file data output by mesh card in mcnp software?

    How to use mdata file data output by mesh card in mcnp software? I converted the mdata data using gridconv.exe, but I don't know how to use the data to identify the section graph for the xyz axis? Does anyone know how it's arranged?
  2. qnach

    A Differential cross section, double differential cross section, triple...

    There are differential cross section, double differential cross section, triple DCS. What are the difference, and why is the names? Thanks.
  3. Ranku

    I Cross Section & Mass: Is There a Relation?

    In the sentence "WIMP-nucleon cross sections of 1.2x10-47cm2 at 1 TeV/c2 WIMPs", there is a relationship between cross section and mass. Is there a general formula that relates the two quantities, in that if there is a certain cross section that means it will be associated with a certain mass?
  4. simonjech

    I Lorentz invariant phase space and cross section

    Can someone please explain to me how can we obtain this integral in eq. 5.27 from eq. 5.26? I quite do not understand how is it possible to make this adjustment and why the (p_(f))^2 appeared there in the numerator and also why a solid angle appeared there suddenly.
  5. C

    I A donut electromagnetic core comprises main section + movable section

    There is a short movable section of cylinder shape in a O-ring magnetic core with DC coil, of course, there are 2 air gaps between the movable section and stator main section. My question: if rotate the movable section, is there a bunch of twisted magnetic lines? The rotation does not change the...
  6. greg_rack

    Engineering Analyzing Shear & Bending on Idealized Cross Section

    As you can see from the picture, the cross section to analyze is idealized and the boom areas resulting from this are given. For POINT A) all I did was: for determining the shear forces, integrating the shear flows over the sides to compute the vertical and horizontal contribution of each side...
  7. amilton

    A Problem in Understanding notation of distributional section

    In this post [Observables][1] By Urs Schreiber he denotes the space of distributional sections in defenition 7.9 by ##\Gamma_{\Sigma}^{\prime}\left(E^*\right) ## That is if ##u \in \Gamma_{\Sigma}^{\prime}\left(E^*\right)## than ##u## is a linear functional that takes as argument...
  8. V

    Optimizing with Golden Section Method: Choosing Alpha for Maximum Efficiency

    My function is f(x1,x2)=(x2-x1 2)2+ex1^2 I understand the equation for finding a point is xk+1=xk+αkdk, where dk=(0,1) and x0=(0,1). For the first step I can choose α1=0.618 (GR), but how do we choose α2? In the solution manual I see they chose 0.382, was this just some arbitrary number? My...
  9. F

    A Puzzled about Section 3.12 of Jackson's E&M book

    Hi wizards, I'm working through Jackson's book on E&M (3rd edition) and got stuck in section 3.12 on expansions of Green functions. I have three questions regarding section 3.12: First, why is Jackson trying to find a Green function that satisfies equation 3.156? To my beginner mind, it...
  10. A

    Resistance of this circuit containing a Circular section

    I understand that the two separate parts make 2/3, but where is 1/12 ohm coming from?
  11. LUFER

    What is the Electromagnetic Cross Section in this plasma deposition process?

    What is Electromagnetic Cross Section? (shock section) Hello, I have a question regarding the manufacturing process of electronic components in the case of the silicon deposition and corrosion process. My biggest doubt is the behavior of the plasma interacting in the reactor, I don't know if...
  12. A

    Engineering Representation of a threaded section

    Greetings! I´m trying to solve the following exercice I have done the following drawing for the cross section and I want to know if I need to add a top view or any other additional view? (is the cross section enough) thank you!
  13. PainterGuy

    Why digital electronics section start with analysis of inverter?

    Hi, Both NAND and NOR are considered to be universal gates. For example, NAND gates can be used in combination to perform the AND, OR, and inverter operations. The same could be said of NOR gate. Then, why the digital electronics section of electronics textbooks almost always start with the...
  14. C

    Fixing the position of a number line in section

    I am having trouble with the spacing and positioning of some number line. Sorry for any format problems. \usepackage{tikz} \usepackage{parskip} \subsubsection{Graphing Real Numbers on Number Line} We can graph subsets of real numbers on the number line. The number lines continue forever...
  15. Anava1001

    A Normalized differential cross section

    Hello, I know that this question might be a bit silly but I am confused about plotting a normalized differential cross section. Suppose that I have a histogram with the x-axis representing some observable X and the y-axis the number of events per bin. I want the y-axis to show the normalized...
  16. samy4408

    I don't understand this problem -- Surface area of a section of a solid sphere

    Sorry i don't understand English very well , if someone want to explain to me this problem?
  17. Rlwe

    Capacitance of infinitely long coaxial cylinders of elliptical section

    I've been able to prove the following inequality $$\frac{2\pi\epsilon_0}{\log\left(\frac{b_1b_2}{a_1^2}\right)}\leq C \leq \frac{2\pi\epsilon_0}{\log\left(\frac{a_1a_2}{b_1^2}\right)}$$ but have no clue how to obtain exact value. Can someone check whether this inequality is correct and show how...
  18. Alpha2021

    A General Relativity: Section 5.1 Homogeneity & Isotropy Analysis

    From the section[5.1] of 'Homogeneity and Isotropy' from General Relativity by Robert M. Wald (pages 91-92, edition 1984) whatever I have understood is that - ##\Sigma_t## is a spacelike hypersurface for some fixed time ##t##. The hypersurface is homogeneous. The metric of whole space is ##g##...
  19. neilparker62

    B Cross section (?) of Great Pyramid from drone footage

    Following is a frame carefully chosen from this drone footage. At about 0:29 into the video the drone is directly in front of one of the four faces (if you know Cairo, you will know which one) and moving from left to right. At that point I have paused and 'frame-stepped' till the moment before...
  20. Prinzmio

    Lowering the Golden Ratio: The Impact on Golden Section Search Efficiency

    Currently my task is to count number of iterations of golden section search verus interval bisection search of a function y = x^2. Golden section search took about twice the number of iterations than interval bisection search. If I lowered the golden ratio from 0.618 to 0.5562 , the number...
  21. M

    Feynman rules and the tree level cross section of two scalar fields

    Hi there. I'm trying to solve the problem mentioned above, the thing is I'm truly lost and I don't know how to start solving this problem. Sorry if I don't have a concrete attempt at a solution. How do I derive the Feynman rules for this Lagrangian? What I think happens is that in momentum...
  22. MathematicalPhysicist

    A Some questions about the derivation steps in the Gravitational deflection of light section in Schutz

    In the screenshots below there are the equations (11.49) and (11.53). I don't understand how did he derive equation (11.53) from Eq.(11.49)? From (11.49) I get: ##d\phi/dy= d\phi/du du/dy = (1/b^2-u^2+2Mu^3)^{-1/2}(1+2My)##. It seems he neglected the ##2Mu^3## since ##Mu\ll 1##, so ##y\approx...
  23. grotiare

    Engineering Question about max stress on circular cross section with two moments

    I couldn't fit in the title, but this is with a hollow circular cross section So currently I am trying to figure what occurs when two, perpendicular bending moments are applied to a hollow circular cross section (one about the z axis, and the other about y). I know that if I was dealing with a...
  24. Johnstonator

    What would be the ideal cross section of an axially loaded cantilever beam?

    Pretty much the title. Just some brain teasers I'm trying to figure out. I can't think of how a cross section would come into play when it comes to axial loading. Buckling? Since the critical force for buckling is proportional to moment of inertia, so theoretically if I have a high moment of...
  25. S

    What are typical Pressures in a test section of a shock tunnel?

    I'm writing a Matlab script to calculate various properties in a shock tunnel. While this might sound silly but I am not well acquainted with the subject and have very few resources to compare. For a mach 6 test section is it reasonable to have a freestream pressure as low as 305 Pa?
  26. B

    Round vs Square cross section tubing

    I want to make some beaching legs for my 30ft, 9T yacht... these are supports either side of the yacht that keep it upright when the tide goes out and it sits on its keel without falling from one side or the other. My question is this, would it be stronger to use sguare or round tube to do this...
  27. O

    A On the relationship between Chern number and zeros of a section

    Greetings. I still struggle a little with the mathematics involved in the description of gauge theories in terms of fiber bundles, so please pardon and correct me if you find conceptual errors anywhere in this question. I would like to understand the connection (when it exists) between the...
  28. Amy_93

    I Statistic uncertainties in cross section plots - how to calculate?

    Hi there, I hope I chose the right forum for my question. So, basically, I'm doing an analysis measuring the number of signal particles in a certain momentum bin i, and doing two corrections: Nsig, i=M*(Nmeas, i-Nbkg, i) Here, M is a matrix covering PID correction and PID efficiencies, and...
  29. M

    MHB Show that there is a 1-km section that he covers in 1.5 minutes

    Hey! :giggle: A cyclist, constantly driving forward, covers a distance of $80$ km in exactly $2$ hours. Show that there is a $1$-kilometer section of this journey that he covers in exactly $1.5$ minutes. Hint: Continuity of the inverse function. So we have to define a function $\phi...
  30. S

    Any clues to the origin of this pic (cross section of teeth)

    At [01:02], this video youtu.be/qwbIu2PzCRs?t=62 shows the following picture. I'm guessing it's either Arabic or Persian. Can someone read the text and say if it gives any clues to its age and origin? If it's even of medieval vintage, it would be pretty remarkable, implying that they may have...
  31. D

    I The 1/v law for U-235 cross section

    The cross section for fission of U-235 is much higher for slow, thermal neutrons than for fast neutrons, for which it is similar to the geometric area. The cross section for slow neutrons seems to decrease empirically like 1/v where v is the velocity of the neutron. What is the qualitative...
  32. AHSAN MUJTABA

    Should I Use Dipole or Quadrupole for Calculating Radiation Pattern?

    I am computing the radiation pattern for that I have to calculate the power per solid angle I found $$m( magnetic moment)=I(t)A$$ where then i took the cross product with $n=sin(\theta)cos(\phi)i+sin(\theta)sin(\phi)j+cos(\theta)k$ After that I moved towards computing the E and B which I know...
  33. A

    Equilibrium temperature in a homogeneous section (stationary regime)

    I believe it is just an arithmetic medium, but I am not sure. Could someone explain to me?
  34. Haorong Wu

    I Where does this formula for absorption cross section come from?

    My professor gave us a formula for absorption cross section, but he said he did not remember where he found it. The formula is given by $$\sigma_a =\frac {1} {| \mathbf E_i|^2} \int_V k \epsilon^{''}_r | \mathbf {E} |^2 dV = k \epsilon^{''}_r |\frac 3 {\epsilon_r +2}|^2 V.$$ Where does...
  35. A

    Equivalent resistance of a section of a graphite ring

    I considered that the lengths of pi/4 and 3pi/4 would be in parallel: 1/R = 1/30 + 1/10 R = 7,5 ohm But the answer is 30 ohm. Where am I missing and how do I calculate the potential of the voltmeter.
  36. R

    A Compton Recoil and the Electron Differential Cross Section

    Hi folks, My understanding of the Compton Effect is that maximum energy transfer to the electron takes place when the photon scattering angle is 180 degrees. For the following please reference Evans "The Atomic Nucleus" ...
  37. J

    A Griffith's Elementary Particles Section 9.7 Electroweak Unification

    1. On pg. 343 Griffith's expresses the weak current in terms of left-handed doublets. jμ± = ##\bar χ_L##γμτ±##χ_L## ##χ_L## = ##\begin{pmatrix} ν_e \\ e \end{pmatrix}_L## ##\tau^+## = ##\begin{pmatrix} 0 & 1 \\ 0 & 0 \end{pmatrix}## , ## \tau^- ## = ##\begin{pmatrix} 0 & 0 \\ 1 & 0...
  38. I

    Connecting Two 30x10mm2 Earth Busbars: Min. Conductor Cross Section

    I have two 30x10mm2 Earth busbars in switchboard, both are placed on insulators, but connected through various parts of switchboard (ground terminal, rails, door, mounting plate...) What is the minimal conductor cross section allowed for connecting this two busbars directly?
  39. B

    I Understanding Nuclear Fusion Cross Section Diagrams

    I'm working on programming a particle simulation that visually shows the nuclear fusion reaction rate of deuterium at different densities and temperatures, but I'm having trouble understanding exactly how nuclear fusion cross section diagrams are supposed to be interpreted. (The simulation...
  40. benorin

    Munkres Topology Ch. 1 section 2 Ex #1

    Mostly I need to clear up a few basic things about functions and their inverses, the problem seems easy enough. Ok, so for (a) I have $$f^{-1}(f(A_0))= \left\{ f^{-1}(f(a)) | a\in A_0\right\}$$ but here I’m not certain if ##f^{-1}## is allowed to be multi-valued or not, the text says that if...
  41. JD_PM

    I Understanding the (polarized) cross section for Compton Scattering by electrons

    I have specific questions, but let's first give context. Initially we have an electron with momentum ##p=(E, \vec p)## and spin state ##u_r (\vec p)## and a photon with momentum ##k=(\omega, \vec k)## and polarization state ##\epsilon_s (\vec k)##. Finally we have ##p'=(E', \vec p')##, ##u_r'...
  42. qnach

    A Software for cross section calculations using .cif files

    Is there any software available to calculate cross section using .cif file?
  43. H

    Matrix and cross section of the Xf -> Xf process

    The attempt at a solution follows as an attachment. If you are only interested in the solution without the derivation, look at page 1 and page 9.
  44. imselva

    Conduction heat transfer with varying cross section

    How to modify this Formula? and arrive at the solution. Q = -K(Th-Tc)A/thickness
  45. G

    Determing the center of gravity of a shaded section

    Determine the volume of the shaded area around the Y-axis by using the theorem of Pappus Guldinus, where value of R = 143,3 cm. a) Determine the area of the shaded section. b) Determine the center of gravity of the shaded section. c) Detrmine the volume by using the theorem of Pappus Guldinus...
  46. Math Amateur

    I Subbasis for a Topology .... Singh, Section 1.4 ....

    I am reading Tej Bahadur Singh: Elements of Topology, CRC Press, 2013 ... ... and am currently focused on Chapter 1, Section 1.4: Basis ... ... I need help in order to fully understand some remarks by Singh just before he defines a sub-basis ... .. The relevant text reads as follows: To try...
  47. K

    I Simple explanation for cross section ratio

    Hello! Is there any simple (i.e. using some physics arguments, without actually doing the math) explanation for why $$\sigma(pp \to \pi^+d)/\sigma(np\to\pi^0d)=2$$ where d is the deuteron? Thank you!
  48. Math Amateur

    MHB Linear Transformations & Matrices: Armstrong, Tapp Chs. 9 & 1 - Explained

    At the start of Chapter 9, M. A. Armstrong in his book, "Groups and Symmetry" (see text below) writes the following: " ... ... Each matrix A in this group determines an invertible linear transformation f_A: \mathbb{R} \to \mathbb{R} defined by f_A(x) = x A^t ... ... "I know that one may define...
  49. P

    Easy tool to see a cross section?

    I need to visualize what the cross section is of an oval tube is at angles of 10 degrees, 20, 30 up to 60. Is there an easy way to do this online somewhere or is there a mechanical drawing trick that can be done to see this result?
  50. MichaelRocke

    Trig Identities - Pre-calculus in a Nutshell - Section 4 Question 1

    My latest attempt \begin{align*} \frac{\sin \theta + \tan \theta}{\csc \theta + \cot \theta} = \\ \frac{\sin \theta + \tan \theta}{\csc \theta + \cot \theta} \cdot \frac{\csc \theta - \cot \theta}{\csc \theta - \cot \theta} =\\ \frac{\sin \theta \csc \theta + \tan\theta \csc \theta - \sin...
Back
Top