Correction Definition and 202 Threads

  1. Z

    End correction of a closed pipe

    Homework Statement Is there a scientiically approved method for end correction of a closed pipe. Homework EquationsThe Attempt at a Solution The formula used is Delta L = (3d) where d = diameter in cm.
  2. Minka Aduse-Poku

    Temperature Correction: Get Accurate Wall Surface Temperature

    Dear All, I have collected temperature data for a period of about 4 months with a device called ibutton attached to the surface of a concrete wall. My problem is the button is made of Stainless steel 305 and exposed to sunlight. I am interested in obtaining the wall surface temperature and at...
  3. tomdodd4598

    Stokes Law/Drag Force corrections?

    Hi there, I have recently been experimenting with solid metal spheres being let to fall through fluids of different viscosities and have recently been introduced to the 'Ladenburg correction'. This correction multiplies the measured velocity of the sphere to obtain the 'correct' velocity used...
  4. H

    Correction term while switching from inertial to body fixed

    Suppose we have an equation in inertial frame A. \begin{equation}\frac{{}^Ad\bf{H}_C}{dt} = \bf{M}_C\end{equation} Now we want to switch to body fixed frame B. For this need to employ correction factor {}^A\bf\omega^B\times\bf{H}_B. Why do we have this correction factor? How to derive this...
  5. C

    QCD Correction to DIS: Evaluating Trace & Lorentz Invariant Phase Space

    I am considering the following virtual correction to the DIS process between a quark and photon. The process on the left in the attachment is one such QCD correction I can make but the diagram on the right is another (I just changed where the gluon vertices lie). It seems to me that both...
  6. F

    Three-phase power factor correction

    Hello. I have a doubt regarding the following problem: 1. Homework Statement Calculate capacitors' capacity to rephase (cos(φF) = 1) the load ZL Homework Equations The formula to calculate capacity in this case is: CY = P(tan(φi) - tan(φF))/ωVrms2 or CΔ = P(tan(φi) - tan(φF))/3ωVrms2...
  7. Safinaz

    Loop correction for quartic Higgs coupling

    Hi all, Has anyone an idea about the loop correction for quartic Higss coupling? In [arXiv:1507.03618v2 [hep-ph]], equ. (13) it's pointed out that the perturbativity constrains on the quartic couplings in the Higgs potential is ## \lambda^2 < 16 \pi^2 ## Which means that loop factor is ##...
  8. I

    Correction to the Eigenvalue -- doubly degenerate case

    Determine the corerctions to the eigenvalue in the first approximation and the correct functions in the zeroth approximation, for a doubly degenerate level. The solution: Equation \left| V_{nn'}-E^{(1)}\delta_{nn'}\right|=0 has here the form...
  9. I

    Derivation of 1st order correction to energy degenerate spec

    Hello there ! I need to derive the formula of first order correction to the energy in the case of discrete level of wave function with descrete spectrum.
  10. I

    Formula- first order correction to the n-th wave func

    Could anybody explain me why indeed we can express the first-order correction to the n-th wave function \psi_{n}^{1} by linear combination \sum_{m} c_{m}^{(n)}\psi_{m}^{o}
  11. Luminescent

    Critical density: question correction

    Hope I'm in the right section for this question! In the big bang model, the expansion of the universe is slowed down by gravity. If there is enough matter in the universe, then the expansion can be overcome and the universe will collapse in the future. The density of matter that is just...
  12. ognik

    Correction to non relativistic KE

    Homework Statement find series expansion of relativistic energy formula, At what speed is there a 10% correlation to the non relativistic KE. Homework Equations $$ E=\frac{mc^2}{\sqrt(1- \frac{v^2}{c^2})} = mc^2 + \frac{1}{2}mv^2 + ... $$ The Attempt at a Solution I found the series above...
  13. R

    Power Factor Correction: Capacitor Bank

    Typically the power factor penalty that a utility charges is only for inductive lagging power factors or leading ones too? i.e. is the penalty for all PF differences from unity or only on the inductive side? e.g. Say I have a lot of motors which bring the PF down & I add a static capacitor...
  14. W

    Momentum Flux Correction Factor

    I'm a bit confused about the momentum flux correction factor which shows up in the conservation of linear momentum equation for fluids. What I am confused about is when the factor is used. The linear momentum equation has its general form and then a simplified form where the momentum flux...
  15. can12345

    Correction Of Transfer Function

    Hello everyone; My question is regarding to velocity effect on transducer diaphragm. When fluid flow is acting to differential pressure transducer's diaphragm, the diaphragm is osculating(vibrating) and there will be fluid flow which is transverse(opposite flow,back flow) to normal fluid flow...
  16. R

    Fermi/Coulomb correction factor for beta decay

    Hi all, Fermi introduced a multiplicative correction factor in order to correct for the effect of the Coulomb field on the resulting energy distribution of ejected beta particles (i.e., either electrons or positrons) following a beta decay reaction. The result is that positrons are accelerated...
  17. E

    How does Atmospheric Correction work?

    I have been reading about it a lot, but I still cannot grasp the concept and procedure of Atmospheric Correction. If, for example, a have a raw image from a satellite, how does Atmospheric Correction do its processes, and what would be the expected resulting image?
  18. jk22

    Relativistic correction to the gravitational force?

    I considered a free falling object in the Schwarzschild metric at rest at infinity and found as approximation the acceleration : $$\frac{d^2 r}{dt^2}\approx -\frac{GM}{r^2}+\frac{3G^2M^2}{r^3c^2}$$ This would mean if there are no sign error in some sense that the force becomes repulsive at...
  19. J

    Relativistic correction of Schrödinger equation

    Hello there, I've been given the relativistic correction of the Schrödinger equation for a free particle: $$ - \frac{\hbar^2}{2m} \frac{\partial ^2\Psi}{\partial x^2} - \frac{\hbar^4}{8m^3c^2} \frac{\partial ^4\Psi}{\partial x^4} + E_0 \Psi = i \hbar \frac{\partial \Psi}{\partial t} $$ How we...
  20. N

    Complex Wave Orientation Correction

    The configuration and dimensions of any experiment are important in determining wave amplitudes. Then why are the orientations of complex waves not considered when they are added? For example in two dimensions; To find a resulting wave at a point P1 from two paths R1 & R2 we have...
  21. W

    Design of Power Factor Correction Capacitor?

    Hello... kindly help me out in designing of power capacitor to improve the power factor as the given load is 950 KWatt and power factor is 0.7, as i want to improve the power factor to 0.92 then what formula i should use to design the capacitor as the Voltage line to line are 400Volts
  22. K

    Need some help -- Power Factor Correction for a Motor

    < Mentor Note -- thread moved to HH from the technical engineering forums, so no HH Template is shown > Hi there. I am wondering if someone can help me.. Below is a question and answer, I need help with IV . Where does the 0.51 and 0.28 come from? I've tried cos and sin and thitha but doesn't...
  23. Safinaz

    Radiative correction with Feynarts

    Hi all, I'd like to ask how to draw the penguin diagram of b -> s gamma process with FeynArts ? It's the diagram at: http://inspirehep.net/record/832732/plots S.
  24. C

    Hartree-Fock correction to e-e interaction

    The corrections to the energy per electron in a jellium model (uniform distribution of positive ion charge approximation to the regulated long range order ionic array) is given by (in units of Ry) $$E/N = \frac{2.21}{(r_s/a_o)^2} - \frac{0.916}{(r_s/a_o)} + 0.0622 \ln (r_s/a_o) - 0.096 +...
  25. Z

    First order correction of wavefunction in degenerate perturbation

    In first order correction of wavefunction, |ψ(1)n>=∑ψ(0)m<ψ(0)m|V|ψ(0)n>/(E(0)n−E(0)m) when any two of the original states degenerate, we replace the two states with their corresponding "good states" to get a new set of "undisturbed" states (ψ(0)m), AND then we determine the first order...
  26. ORF

    Has a real clock corrections, with respect to an ideal clock?

    Hello In Special (and General) Relativity, has a physical (real) clock corrections, with respect to an ideal (mathematical) clock? For example, the physical clock has mass, so it will affect its own measure. This is only an example I thought, I don't know if there are more corrections...
  27. DataGG

    Perturbation theory, second-order correction - When does the sum stop?

    I've no idea if I should be posting this here or in the general forums. This is not really an exercise as much as an example. I'm not understanding something though: 1. Homework Statement Using perturbation theory, find the exact expression for the energy given by the hamiltonian...
  28. P

    Double Counting Correction in LDA+U: AMF vs. FLL

    Hi there, I'm not sure if someone here can help me because the topic is quite specific. In LDA+U Calculation one have to substract the Double Counting from the DFT functional. There are two main possibilities to do this: 1.) Around Mean Field (AMF) 2.) Fully Localized Limit (FLL) I...
  29. M

    Percent correction for Magnetic Field vs. Electric Field

    Hi guys, In the photo is the problem. We set Fb =Fe to show for E then out E into the Voltage equation to get V=vlB. However, if we won;t ignore the gravity force, what is the percent correction? (Note: q =Electron)
  30. Q

    Power Factor Correction - Capacitor Sizing wrt Motor Speed

    Please have a look at the following links: http://www.eaton.com/ecm/groups/public/@pub/@electrical/documents/content/sa02607001e.pdf (Table 3) http://www.electrical-installation.org/enwiki/Power_factor_correction_of_induction_motors FigL24) - For power factor correction, why would the...
  31. P

    Kinematics Questions: Acceleration, Velocity, and the Speed of Light

    Hi, I have some questions regarding Kinematics: 1. If an object is accelerating at 9.8 m/s^2, how much time does it Need to reach ten percent of the Speed of light? Speed of light: 299 792 458 m / s -> 10% -> 299 792 45,8 m / s t = v/a -> 299 792 45,8 m / s / 9.8 m/s^2 = 3 059...
  32. M

    Exploring Higher Order Relativistic Corrections for Hydrogen Atoms

    For hydrogen atoms, all book take correction up to 1/c^2 where the perturbation is -P^4/8*m^3*c^2. And they go solving it by sandwiching p^4 term where they consider p^2 = 2m*(1+e^2/r). and they square it to solve for p^4. To get a better view of perturbation to first order please see...
  33. A

    Correcting Calculus Derivative: x(t) = A cos(ωt - \varphi)

    I'm brushing up on calculus. I don't see how this derivative works. x(t) = A cos(ωt - \varphi) v(t) = dx / dt = - Aωsin(ωt + \varphi) I get that the derivative of cosx is -sinx. I get that the omega is brought outside the cos function because of U substitution. Why does the the...
  34. K

    How to Calculate the Value of a Capacitor for Power Factor Correction

    Homework Statement A small industry operates from 220 volts supplied by a utility. The small industry represents a load to the utility that represents 22,000 watts and a power factor of 0.8.Determine the value of a capacitor placed at main voltage panel to correct the circuit to unity power...
  35. A

    Quantum yield: fluorescence spectrum correction

    Hello, I hope all is well, I have a few questions regarding fluorescence spectral corrections. I have run into an issue with corrections on the instrument I'm using. I have obtained spectra for a few compounds where the correction was working properly and achieve the results as expected. When...
  36. J

    The one-loop correction in Lehmann-Kallen form

    Hi. I would like to ask a question about Chapter 15 in Srednicki's QFT book. In chapter 15, after eq. (15.12), he compares eq. (15.12) ## \mathrm{Im}\bm{\Delta}(k^2)=\frac{\mathrm{Im}\Pi (k^2)}{(k^2+m^2-\mathrm{Re}\Pi (k^2))^2 + (\mathrm{Im}\Pi (k^2))^2}## with eq. (15.8)...
  37. T

    Alternative to Von Neumann bias correction method

    Hi I have discovered that the Von Neumann bias correction method only works when the bias is 100% stable, for example tossing the same loaded coin again and again. Does anyone know of a bias correction method which can correct an unstable bias? Is this impossible? Edit: Let's say I have a...
  38. C

    Bessel's correction and degrees of freedom

    Wondering about degrees of freedom. So basically let me express my current understanding: Comparing the statistical errors to the residuals, the former involves taking a subset of observations from a population and comparing them to the population mean, while the latter involves comparing the...
  39. Q

    Understanding Reactive Power Flow in Power Factor Correction

    When you connect a capacitor across an inductive load, reactive power (Q) flows back and forth between capacitor and inductor, so (ideally) the generator doesn't need to supply Q to the load. My question is, why doesn't the capacitor supply Q to the generator as well? If only a capacitor were...
  40. I

    Engineering Correction to my academic plan to become a Drilling engineer

    I am currently a transfer student doing a BA in physics and two minors in business. At this time I cannot change my major unless it is advisable to go back and complete a BS in physics instead of completing a BA. I want to be able to secure my chances of landing a entry level Drilling...
  41. C

    Muon Decay Width Correction: Derivation & Origin

    In my class notes, the muon decay width is: \Gamma_\mu=\frac{G^2_F m^5_\mu}{192\pi^3} Yet, in Wikipedia (take that for what it's worth) it says that, once the corrections have been applied, the muon decay width takes the form: \Gamma_\mu=\frac{G^2_F...
  42. J

    Why GRT is the proper correction of gravitomagnetism?

    The best experimental tests of the general relativity: of frame dragging by Gravity Probe B, use calculations from approximation of GRT, called gravitomagnetism: http://en.wikipedia.org/wiki/Gravitoelectromagnetism It was originally introduced by Oliver Heaviside in 1893 as expansion of...
  43. K

    Lande' g-Factor: Is a Reduced Mass Correction Needed?

    Ok. The Lande' g-factor is given as g = g_L \frac{J(J+1)-S(S+1)+L(L+1)}{2J(J+1)} + g_s\frac{J(J+1)+S(S+1)-L(L+1)}{2J(J+1)} Most sources say that g_L = 1 exactly, but Bethe and Salpeter p214 seems to indicate that there should be a correction for reduced mass. g_L = 1- \frac{m_e}{m_i} Is...
  44. N

    (Peskin and Schroeder) Numerator of vertex correction

    Hi I am studying qft with worldwidely used text, written by Peskin and Schroeder, An introduction to qft. I have trouble with the calculation of thr numerator on pp. 192. I got additional term ## 2m(z-xy)(mγ^μ - p^μ) ## between spinors, which seems not vanishing. Is there any idea to treat this...
  45. T

    Power Factor Correction for a 230V Single Phase Lighting Installation

    The problem statement Using the nomogram of FIGURE 10, calculate the size of capacitor bank to give a final power factor of 0.95 for a single phase, 230 V, 50 Hz lighting installation which has a load current of 17.5 A and operates at 0.8 pf. The nonogram gives a value k = 0.44...
  46. M

    Active Power Factor Correction Evaluation Board

    Homework Statement Hi, I'm an electrical engineering degree student from Perlis University, Malaysia (UniMAP) and I'm currently doing a Final Year Project. The title is Active Power Factor Correction. I'm evaluating a Boost APFC Board from STMicroelectronics model EVL6562A-TM-80W. The problem...
  47. A

    Deriving the Correction Factor for Non-Ideal Spring Frequency Equation

    Homework Statement In general, I know that you can use the equation ωn=[k/m]^0.5 to calculate the natural frequency of a hanging spring and mass system. However, for a non-ideal spring (where the mass of the spring isn't negligible) a correction factor is added to the equation and it...
  48. H

    Why do we use Local field correction?

    Knowing the dielectric constant of a medium we can earn the electric field at any point in that medium which is deferent from the applied external electric field. So why do we use the Local field correction?
  49. J

    Perturbation Theory: Calculating for the correction on the ground state energy

    Homework Statement Homework Equations E_{1}=<ψ_{1}|V(r)|ψ_{1}> The Attempt at a Solution That is equal to the integral ∫ψVψd^3r So I'll just perform the integral, correct ? But r is not constant here right? So, I' ll keep it inside the integral? How should I continue? Please...
  50. S

    Why cosmic ray intensity needs correction with pressure?

    Hi guys, I cannot understand why we need to correct cosray intensity with pressure and why the equation that describes the phenomenon is I=Io*exp(-a(Δp))? I want to know the phsyical meaning of this(i assume,experimental) result... Thank you...
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