What is Transient: Definition and 200 Discussions

ECHELON, originally a secret government code name, is a surveillance program (signals intelligence/SIGINT collection and analysis network) operated by the United States with the aid of four other signatory states to the UKUSA Security Agreement: Australia, Canada, New Zealand, and the United Kingdom, also known as the Five Eyes.Created in the late 1960s to monitor the military and diplomatic communications of the Soviet Union and its Eastern Bloc allies during the Cold War, the ECHELON project became formally established in 1971.By the end of the 20th century, the system referred to as "ECHELON" had evolved beyond its military and diplomatic origins into "a global system for the interception of private and commercial communications" (mass surveillance and industrial espionage).

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  1. M

    Transient Response of Straw Filling with Water

    Okay, since the most fluids I've studied are from the Euler equation in the context of plasma physics I may be asking a trivial question, but here goes anyway. What I am wondering about is why there is a transient response when I cap a straw with my finger, place the straw in water (while still...
  2. M

    How Do You Calculate Transient Current with Given Circuit Components?

    Homework Statement Battery Voltage = 12 V, C = 1uF, R = 1Kohm, L = 0.2H. Find Transient Current. See Fig for more details. Homework Equations i = Cdv/dt. The Attempt at a Solution (I think the problem doesn't make sense)
  3. S

    Transient Tank Filling Problem (Related Rates?)

    Homework Statement "Consider the tank and water supply system as shown in the figure below. The diameter of the supply pipe, D1 = 20 mm, and the average velocity leaving the supply pipe is V1 = 0.595 m/s. A shut-off valve is located at z = 0.1 m, and the exit pipe, D2 = 10 mm. The tank...
  4. B

    Help with transient mass balance for desalination by destillation

    Homework Statement Homework Equations ordinary mass balance The Attempt at a Solution So far I have gotten: d[rhob*V]/dt = Min - ?
  5. C

    Gear strength service factor / transient load calc

    Hey guys, I have searched for information, but I'm looking for an explanation on the difference between a safety factor and a service factor for gearing, and how you would use the latter of the two in calculation (i.e. does it work like a safety factor?). Does anyone have any references that...
  6. K

    Engineering Transient current in inductance circuit

    Homework Statement I have posted my complete question http://imagebin.org/110458" [PLAIN]http://imagebin.org/110458. It is about a DC circuit with an inductor and a static magnetic field applied on a part of the circuit loop. An expression for the transient current needs to be found. My...
  7. D

    Capacity Matrix - transient heat

    Initial Nodal Temperatures Please Help, I am learning how to do 2-D time-dependent linear heat conduction for Finite Elements, and am progressing but have a question with nodal heat values. I am using the explicit Euler Forward Difference algorithm and as such need to set initial nodal...
  8. F

    Transient heat transfer in heat exchangers

    Considering an engine generating thermal heat at 140 kw and when the generation starts the thermal equilibrium of the engine will be distrubed , a radiator is installed to cool the engine this radiator cool the engine through flow of water and water is cooled inside a heat exchanger with air ...
  9. M

    2D Finite Element Transient Heat Problem

    Hi everyone, I'm currently working on coding a finite element heat problem in Matlab that is as follows: I have a cross section of a beam made of an isotropic material (concrete) that is placed in a furnace, and the outside temperature is raised at a constant rate. I am interested in...
  10. M

    Transient analysis (RC) question problem

    hello friends... i am having following problem in this question. first i don't understand how they have calculated R equivalent=5/6.i think its value should be 25Kohms. will it be different at 1ms and 4ms or same ?\\ i shall be thanks to u . in one picture is the problem n in other...
  11. K

    Transient response of a control system.

    Hi guys. I am a Mechanical Engineering Student but we've a course called Control systems. My question is why does any system(physical like fan,motor or electronic like amplifier) have a TRANSIENT RESPONSE and specially why do electronic components like amplifiers,diode or for that matter any...
  12. W

    Medical The effects of high blood pressure transient

    If the blood pressure jumps from a long term pre-hypertension stage (140/90) to 175/110 for ten hours, and then calms down to pre-hypertension stage again, are there any long term effects on the body for sustaining such high blood pressure? From what I've been able to find out, high blood...
  13. P

    Eddy Current transient problem

    Homework Statement For my internship I need to solve a problem with eddy currents involved. The problem shows a U-shaped aluminum slider (see attachment) with steel plates on the left and right side mounted on it. In this aluminum slider there are 10 magnets (5 at each side) with a...
  14. N

    2D transient analysis for heat conduction

    I need a fem code either in MATLAB or fortran to refer to as I am stuck at some places. Please help.
  15. A

    Transient Heat Transfer Gods?

    Hi Anyone with experience with transient heat transfer please can you help me. I have attached an image that is a simple stirling engine schematic. One half is essentially a pipe that is heated from one end and kept at room temperature at the other end. Inside it is a displacer that is not...
  16. R

    Transient (Time domain) in transmission lines

    Hello. I am watching this video: https://www.youtube.com/watch?v=xIQtnQ9XPbE and he says there: I see that the wave turns into a "normal" sinus in the end, but it's not constant. I think, that even on an unmatched transmission line, the waves should go back and forth, but eventually...
  17. S

    Modeling Transient Dynamics (Equilibration Processes)

    Hi, I am trying to find some texts (and/or journal articles) related to the mathematical modeling of transient dynamics. I am a civil engineer and figured physicists/applied mathematicians could tell me where to look. The systems I am looking at are finite dimensional and tend to equilibrate...
  18. S

    Newton-Raphson Iteration in Transient Thermal Analysis

    Hi, I have been quite confused about this for sometime now. It has not been mentioned clearly in the books/references that I have looked into. In transient thermal analysis using FEA with implicit scheme or the Crank Nicolson scheme, are there Newton Raphson iterations based on the...
  19. A

    Designing a Heat Pipe for an Indoor Solar Cooker: Tips and Fluid Recommendations

    Hi, I am studying the heat transfer in a stirling engine. The basic situation is a pipe blocked off at both ends, with air inside, and a displacer also inside, that moves backwards and forwards inside. It is not tight against the walls of the pipe, and air can pass around it. One end of...
  20. S

    Force Matrix for Transient Thermal Analysis

    Hi, I have developed a 2D transient thermal analysis FE code which doesn't seem to be correct. I am sure there is a conceptual problem in the formulation itself which I have not been able to understand and could not find concrete information in books. I am putting up the question in a...
  21. C

    Transient solution for a semi-infinate solid from a pipe

    Does anyone have a solution for the heat transfer from a pipe into a solid. I am looking for the temperature in the solid based on radius and time and also the heat transfer based on time. The temperature in the pipe (surface of the solid) is constant. The solid has a constant lower temperature...
  22. N

    Finding Velocity from Force, Comsol Multiphysics (transient)

    Hi, I am using Comsol Multiphysics to model a magnetic plug surounded by water in a tube. The plug interacts with a magnet and a force is induced. Since I am using the ALE moving mesh option, i have defined the boundaries of the geometry to move with the velocity of the plug. This...
  23. L

    Engineering Overdamped Series RLC Circuit Transient Response

    Homework Statement Find the voltage across each component is an overdamped RLC circuit. The circuit is powered by a square wave of peak voltage 2 V. The square wave is used to model a DC source. Homework Equations Vs(0)=-2 (Everywhere else in the transient response, Vs=2)...
  24. I

    Comsol Transient Vibration Analysis

    hi all.. How can i describe initial conditions or initial forces in comsol(like wave forms such as ramp or parabolic)? I couldn't find it in the manual. in ansys, i do it in time steps(in solution options).(like t=0, F=10 t=0.001 F=0) I tried to give initial displacements to the points but...
  25. W

    Laplace help on a DC transient RC circuit

    Laplace help on a DC transient RC circuit ? PLEASE -------------------------------------------------------------------------------- I HAVE A RC CIRCUIT WHERE R1=100Kohm and R2=1Mohm and C=2.1micro farads with a Vin =10V, In order to calculate the voltage through the capacitor I...
  26. W

    Engineering Laplace help on a DC transient RC circuit ? PLEASE

    I HAVE A RC CIRCUIT WHERE R1=100Kohm and R2=1Mohm and C=2.1micro farads with a Vin =10V, In order to calculate the voltage through the capacitor I deduce the following formula, Vc(s)=V/S {(((R2×1/Cs)/(R2+1/Cs)))/(((R2×1/Cs)/(R2+1/Cs)+R1) )} I then need to produce a laplace transform...
  27. J

    Transient heat transfer problem in cylinderical coordinates

    y Could some one please help me. My professor for a lower level programming class (in labview) has given the class the following assignment. This is not a heat transfer class and he has not spoken/taugh us anything related to heat transfer. He emailed us a few pages from a heat transfer...
  28. R

    Changing the time step in a 2D transient heat transfer

    Homework Statement I am working on a Matlab code that will solve a temperature grid for a 2D transient heat transfer problem. The code seemed to be working well but when I changed the timestep (to find timestep independance) I noticed that the larger the timestep, over the same duration, the...
  29. MathematicalPhysicist

    Reccurent vs. Transient in Stochastic proccess.

    I have a few quetions which I'm trying to answer, hope someone can hint me to the right answer. 1.Prove/disprove that there doesn't exist a Markov Chain with transition matrix which all of its entries are positive and which it has infinite transient states and infinite reccurent states. 2...
  30. P

    Solve Transient Analysis Problem: Find I0

    i was trying to solve this question(file attached), but i can only come up with the answer: i assumed iL=0 at t=0, hence arrived at this: IL(t) = 6mA(1 - exp(-100000t)) i can't figure out how Io came about. can someone come it my rescue and tell me how the I0 came into play. Kind...
  31. C

    One dimensional transient heat flow of a hoop

    1. Problem: derive the energy balance from first principles of a hoop of inner radius ri, outer radius ro. the hoop material has a density of rho (p), heat capacity of c and thermal conductivity k. the center of the hoop has a temperature of T1 and the gas inside the hoop has a convection...
  32. B

    Transient inviscid incompressible pipe flow

    Hello I am trying to better understand transient fluid dynamics in pipes. First, I am attempting what I believe should be relatively simple problem. I have a constant area horizontal pipe partially filled with a stationary incompressible inviscid fluid. The part of the pipe that is filled is...
  33. Q

    Understanding Output Value and Rise Time in Transient Response Analysis

    hello..can anyone help me? i have the figure in the attachement, and i need to determine the final output value and the rise time..can first anyone explain to me what do we mean by output value and rise time..then what is the formula to calculate them?or we must use MATLAB commands to do it...
  34. T

    How to Resolve Singular Matrix Error in COMSOL Transient Solver?

    I am currently just running a normal 3D incompressible flow problem in COMSOL 3, and end up with the following error: Error: Time 0: Error in residual computation: The_relative_error_is_greater_than_the_relative_tolerance For the direct solver. Last time step is not...
  35. J

    Engineering First Order Transient: RC Circuit

    Homework Statement http://i.thespiffylife.com/files/1/trans1.jpg i have to find Vc(t) Homework Equations I know that Vc(0+) = Vc(0) = Vc(0-) and Vc = Vs*e^(-t/RC) The Attempt at a Solution What I'm unsure on is what the equivalent resistance of the circuit would be so I could find the...
  36. P

    Understand Electrical Fast Transient (EFT) Meaning

    Can anyone explain to me the meaning of the terms : Electrical Fast Transisient (EFT)? Thanks
  37. R

    Transient conduction with finite element analysis

    Homework Statement Hi, I've got a civ engineering problem relating to conductive heat flow using finite element analysis. I'm investigating the dissipation of heat from square and circular pile foundations. I'm applying a thermal load to the centre of the concrete pile which induces heat...
  38. R

    Transient conductive heat flow using finite element method

    I'm looking at project investigating thermal dissiplation around circular and square concrete piles, resting in a homogeneous material (soil) using two-dimensional finite element analysis. I'm applying a transient thermal loading cycle to the centre of the concrete pile over a 7-day test...
  39. M

    Explore Alternative Transient Analysis Codes for Neutronic Operations

    At the moment I'n involved with a project that is using the S3K transient analysis code. I was wondering if anyone knows of a different code that will perform transient neutronic operations. Thanks in advance
  40. L

    How to Solve 1-D Transient Heat Transfer for Constant Temperature Surfaces?

    I am a little confuse here. I am trying to solve the 1-D Transient Heat Transfer for a Constant Temp. Surfaces "wall". The PDE is \frac{\partial T}{\partial t}=\alpha \frac{\partial ^2 T}{\partial x^2} T(to)=200*x I am not so sure about how I'm suppose to get the Temperature profile any...
  41. P

    Femlab transient n-s problem

    Homework Statement I have to solve transient n-s equations using femlab for a plenum, inlet of which is connected to a compressor, now at compressor exit i know values of axial velocity coefficient at different time steps using which i can generate a Fourier interpolation function which i need...
  42. H

    MOS capacitor transient response

    Hello. Suppose we have a MOS capacitor (n-substrate). When we give negative voltage the majority carrier (electrons) are repelled from the oxide-substrate interface and move towards the bulk. Say the bias is -0.3 volts. The substrate is depleted and in steady-state. Suddenly if the bias...
  43. M

    1D/2D Transient Heat Conduction (Diff. Eqs)

    Homework Statement My problem is not necessarily the 2D problem, it's getting the answer in one dimension (I have the y-direction). The problem is the boundary conditions...anyways. Solve for the temperature of a 1D transient metal bar, with the following boundary conditions. Imposed...
  44. D

    Transient thermal problem

    Let's say I have a box, mounted to a plate in a vacuum (pure conduction). The system is initially at a steady state at temperature Ti. The plate then begins cooling at a rate of 3 C/min. The box is going to cool at some rate, and with some time constant. For this test, I have place a...
  45. RadiationX

    Engineering First order Transient Circuit

    I'm having serious trouble understanding how to solve this problem using the differential equation method ( I MUST use this method). I provided the answer but my solution attempts are not producing the same result. Here is the problem...
  46. RadiationX

    Analyzing First Order Transient Circuits Using Differential Equations

    Please click the image to make it larger: http://img360.imageshack.us/img360/2049/82009866sy5.th.jpg To solve this circuit I'm going to use the differential equation approach. I'm concerned with the voltage across the capacitor at V_c(0^-) and V_c(0^+) At position 1 before the switch...
  47. S

    MATLAB Matlab code for transient 2 D thermal problem

    hi i want MATLAB coding for transient 2D Thermal problem pls help
  48. dav2008

    [Thermodynamics] Transient Analysis of an air-filled tank

    Hey I think I'm missing something fundamental in this problem. The problem reads: a 1 m3 tank initially contains air at 300 kPa, 300K. The air slowly escapes until the pressure drops to 100 kPa, via a process where pv1.2=constant (v being specific volume) Find the heat transfer for a...
  49. Ivan Seeking

    What Are Transient Lunar Phenomena?

    http://www.planetfusion.co.uk/~pignut/tlp.html also see http://www.guardian.co.uk/life/farout/story/0,13028,1315487,00.html When I saw this I thought about the Astronaut who while orbiting the moon saw a flashing light on the dark side. He reported the light and was told to watch on the...
  50. Ivan Seeking

    Rare transient luminous event photographed in upper atmosphere

    http://news.nationalgeographic.com/news/2003/06/0625_030625_atmospherethunder.html
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