Loss Definition and 841 Threads

  1. T

    Why Choose IGBT Over MOSFET for Low-Frequency Applications?

    Apologies upfront, I have a backlog of PF threads I have created not replied to...I will endeavour to do so when I can. So I've read that IGBTs are more efficient than MOSFETs for lower than 20kHz frequencies (and are capable of use for high voltage rating and better performance than ordinary...
  2. G

    Possible webpage title: Troubleshooting Synchro Signal Voltage Loss in System A

    Hi, I am currently having an issue and hope someone can help me out! I have a Digital to Synchro card on my server that will transmit the synchro signal voltage to various component. For this issue in facing, System A takes in 4 sets of data. Thus, there will be 4 sets of S1 S2 S3. At System A...
  3. M

    Liquid volume loss during pressure test

    Hi, I'm doing a pressure test with a liquid medium. I have a fixed volume and I know the pressure drop, and temperature change - how do I calculate volume of liquid lost in a leak?
  4. A

    Heating a small greenhouse - heat loss

    I have to build a small green house and to calculate if one heating wire is enough (or even too much...) Just for my curiosity I would like to understand the physics implied in this. The starting point is the desired dimensions: two modules of greenhouse with the following dimensions: 60 cm...
  5. Runei

    Why do leaving groups detach from molecules?

    Hi, My question is short and very simple: Is the loss of a leaving group primarily a random event? What is the actual mechanism that initiates that a specific leaving group.. leaves? Thanks in advance :)
  6. physea

    I Head loss in a circuit of pump and pipes

    Hello! In an experiment (I don't have the details) the predicted head loss in a circuit of pump and pipes was higher as the flow rate increased, than the actual head loss (pressure differential). Can you tell me please what could result in that? What systematically acting factor created an...
  7. jedishrfu

    The Loss of Creativity as Technology Rises

    Sadly, yes. https://www.livescience.com/15535-children-creative.html and the actual study is here: https://www.nesacenter.org/uploaded/conferences/SEC/2013/handouts/Kim_Creativity-Crisis_CRJ2011.pdf My experience is from working with kids over the years and comparing notes. I grew up without...
  8. K

    Calculate the rate of potential energy loss of water in a pipe

    Homework Statement Question: what rate does the water lose gravitational potential energy? Data: I have a pipe that water is flowing through and the pipe has 2 sections. In section 1: - the pipe is 11.9m above section 2 so, h = 11.9m - the velocity of water is $$v_1 = 0.3240ms^{-1}$$...
  9. P

    I The physics of a missile with uniform rate of fuel loss

    Hello everyone! I'm at a loss trying to figure out the specific force that pushes a missile at rest off the ground, to the high sky. Considering a missile with constant mass, and an independent initial total fuel mass. The rate of fuel mass being expelled out of the missile is constant, in...
  10. Oscar Gonzalez

    How to calculate flow loss between 90 and 45 degree fittings

    Hi everyone. Let me give a little bit of background on the problem I need help understanding. I want to plumb an aquarium that has a sump and move the water from the sump to the main aquarium using a pump and 1" PVC pipe. The total system pipe length is going to be roughly 10 feet total with...
  11. M

    Speed at the top of the loop with energy loss from friction

    Homework Statement If the car is going 30 m/s half way up the loop and loses energy due to friction at a rate of 2.0J per meter of track, how fast will it be going at the top? (this is question related to the loop of roller coaster track, with radius 20m.) Homework Equations 1. Ki + Ui = Kf +...
  12. MacLaddy

    Pressure loss in an HVAC system

    I'm working on my first engineering project in the real-world and I'm hitting a bit of a snag. It's regarding pressure loss analysis in an HVAC system. We have a system that is capable of providing a maximum of 2.0-in.wg pressure at the air handler, but we are finding very little air movement at...
  13. H Tomasz Grzybowski

    A Dependence of loss factor tan(δ) upon H in MnZn ferrites

    There is ηB constant given as a hysteresis material constant. But there is the question: what is the limit of applicability of the formula Δ(tan(δ)) = ηB⋅ΔB⋅μe? In particular I think I want to use ferrite with μi = 2000 or so. Up to what H value will tan(δ) increase linearly with B ?
  14. K

    A A question about the information loss paradox

    In the information loss paradox, people say that in quantum mechanics , time evolution is unitary. They usually do not say anything about the measurement process of if they do, they briefly say that the measurement process does not violate unitarity either if one takes into account the...
  15. D

    Is the mass of Liquid N2 and its rate of mass loss related?

    Homework Statement So I'm doing an experiment at uni which I have to find out the specific heat capacity of given small solid cylinder. We are given an insulated canister(a dewar flask) standing on a scale where we have to pour Liquid Nitrogen(hereafter will be referred as LN2) in. A cork with...
  16. longz

    Pressure loss to double wall pipe (ventilation)

    Hi every body, I need help to calculate the pressure drop to double wall pipe with information as below, i understand need calculate pressure loss to the straight pipe, elbows and supports but I don't know exactly how. - Fluid : air - Double wall pipe (stainless steel) with outer pipe...
  17. T

    Need to figure out heat loss as water passes thru a pipe....

    But not for the reason or application you might think...lol I live in SE Texas, just south of Houston. It is hot as balls here in the summer. (Which accounts for three of our seasons here) My neighborhood is on a "community well" type water system, and the well is in the back of the...
  18. P

    Understanding sound transmission loss (TL)

    In considering a sound wave (in air) incident on a wall, the transmission loss (TL) is calculated by the equation TL (dB) = 10*Log (W1/W2) where W1 = sound power incident on wall W2 = sound power transmitted through wall Based on this understanding of TL, I wish to determine the extent to...
  19. R

    Heat Loss Through a Short Cylinder

    Homework Statement A short metal cylinder 145 mm in diameter and 145 mm high at 1045 K is suddenly exposed (all sides exposed) to a room air temperature at 300 K with h=25 W/m².K. Assume that for the metal k=40W/m.K, den=7800 kg/m3 and Cp=c=600 J/kg.K. Estimate (a) the time required for the...
  20. D

    Free Space Loss at Low Frequencies: Is It Really Zero?

    I know that path loss is proportional to the square of the distance between the transmitter and receiver AND is also proportional to the square of the frequency in use but what does it mean when a free space calculator shows a negative number? How is it possible to get zero loss? For instance...
  21. T

    Heat gain (or Loss) in steady state from Metal Rod

    Hello, I got this problem but I don't know How can Find Heat loss (or gain) - Q3 - from the curved surface of the metal rod to the surrounding. This is the problem: A metal rod, of diameter (d) and length (L), runs between two hot walls at temperatures, T1 (Wall 1) and T2 (Wall 2)...
  22. R

    Size expansion vessel to reduce pressure loss

    Hi all, Given: I have a pressure vessel of 1000M^3 filled with water with 8 bar pressure. On this pressure vessel I have installed a valve and a expansion vessel on top of the pressure vessel. The expansion vessel is prepressurized to 8 bar as well. Question: when I open the valve i lose 20...
  23. S

    Loss of Significance: Why Does Bisection Method Fail for Large Intervals?

    Homework Statement Hello! I am not sure if this is the best place to ask this question, but I need some help. So i use the bisection method to find the zeros of a function. When I do it for sin(x), with the initial interval being ##[10^6 \pi, (10^6+1) \pi]##, the program enters an infinite loop...
  24. B

    How can I calculate heat loss from a pipe system in a building with 9 floors?

    halo every one... i have question . if i have pipe inside building with 9 floor's length ,and i have calorie meter between the incoming and outgoing pipe's. how i can calculate the losses of pipe if i now that temperature inside building is 22. i want to be sure that the system working normal. i...
  25. K

    Finding Depth of Water Loss Using Surface Area

    Homework Statement A city with 30,000 residents lies next a lake which is their only source of water. The average family of four in this city uses 1100 liters of water per day. Neglecting rain and evaporation, how much depth would the lake lose per year if it covered 40 square kilometers...
  26. Blank_Stare

    Electric conductivity loss due to weather on electric fence wire?

    Greetings Denizens!, I'm building a small "zapper" for the purpose of keeping critters away from a deer feeder. Other than volts and amps ratings, I believe it is, for all intents and purposes an electric fence, just in a unique configuration (shape, not electrical specs - those are within the...
  27. B

    B Big Crunch, Big Bang and information loss

    In compression of information, once any patterns have been 'condensed' as much as is possible, the information appears entirely random. Any further compression produces loss of information and the quantity of information required to encode it is increased. In one theory it is supposed that all...
  28. R

    Calculating Heat Loss in a Series Circuit

    Homework Statement Determine the heat loss in the circuit that is connected in series with two batteries (12 V and 6V) and two resistors (6ohms and 4 ohms). Homework EquationsThe Attempt at a Solution I used the difference in P = V^2/R, the power dissipated in the circuit, to calculate the...
  29. F

    Calculating Heat Loss in Pipes with Air Flow and Water Surrounding

    I am new and have a math and finance background. Because of my work I am starting to get into engineering related questions, specifically in piping. I flyfish a lot and can give pointers to anyone that helps me with my questions. Say I have a 5-10' length of pvc, metal or copper pipe that is 4...
  30. Timothy Schablin

    B Volume Compression in Cylinders: Does Diameter Affect Rate of Loss?

    Say we have 2 cylinders with the same volume capacities, but different radii, and a plunger to 'squeeze' the contents. We apply the same force to each plunger. Will the cylinder with the larger radii lose volume faster? Or will they be equal?
  31. Kevin Shen

    Electrical Power Loss Equations Confusion

    Why is the equation Power Loss = I^2*R rather than Power Loss = V*I? What I mean is why use I/R to represent V? Also if Power Loss is equivalent to V*R, doesn't step up transformers which creating higher voltage also cause Power Loss to increase which contradicts to textbooks stating that power...
  32. Chronos

    I Testing the information loss problem

    This paper; https://arxiv.org/abs/1704.08613, Entropy evolution of moving mirrors and the information loss problem, discusses a proposed method to test the information loss paradox posed by black hole evaporation. Several possible outcomes are discussed, including a firewall scenario...
  33. Benoit

    Eddy current loss in solenoid half-filled with magnetic core

    Hey ! Let's say I have a solenoid that is only half-filled with a magnetic core. Now I want to know what is the loss due to Eddy currents. First, I want to find the magnetic field with Ampere's law. With this kind of geometry, I'm not even able to apply Ampere's Law ! have of picture here of the...
  34. hemakorn

    How can i find energy loss from acceleration vs time graph

    I use accelerometer for find an acceleration vs time graph from drop test. how can i find energy loss from acceleration vs time graph thank you
  35. Frov_ken

    Friis Path Loss on a Segmented Path Derivation

    Let's say we have a path Length AC. Point A transmits a signal at Ptransmit. From Friis' Path Loss formula: (assumming Gain for receiver and transmitter antennae are 1.) ##P_{received} = P_{transmit} (\frac{λ}{4π* LengthAC})^2## ,when point C contains the receiver. What if I divided this into...
  36. T

    Energy Loss During Total Internal Reflection

    When a laser beam reflects during total internal reflection, how much of its intensity is lost? I can't the use Fresnel equations as this is for total internal reflection.If you don't know the answer to the above question, what about the same question, but for mirrors instead? What are the...
  37. X

    Calculate the power loss in electrical cable

    Hi I'm trying to calculate the power loss over an electrical cable. The information of the system is: Maximum current of 20.92 A per unit at 34.5kV The cable has the following properties: DC Resistance at 25 deg C (0.1672 ohms/1000 ft) AC Resistance at 25 deg C (0.1672 ohms/1000ft) The length...
  38. M

    Relationship of discharge and minor loss coefficient

    What is relationship between discharge coefficient and minor loss coefficient. Am I right with that equations? hl – minor head loss k – minor loss coefficient ρ – air density A – pipe cross section area Cd – discharge coefficient Δp – pressure drop u – air velocity m – mass flow here is...
  39. D

    How Do You Calculate Insertion Loss in a T Network?

    Homework Statement [/B] I am trying to follow a given example as part of my notes. The example is described below Using the equation below calculate the insertion loss of the T network of figure 20 (figure 20 is in the attachment) given the values in the table. I am given a transmission...
  40. ScottAllenRauch

    Fluid Flow Loss Analysis Using Real Gas Properties

    I am trying to model fluid flow and losses through a component (e.g., pipe) using REAL GAS properties since 1) I have access to RefProp from NIST, and 2) I am dealing with refrigerants, which are far from ideal. I have seen nowhere an analysis of fluid flow losses (e.g., drag, friction...
  41. S

    Estimation of material loss through electrical resistivity

    Hi all, I'm doing a little project about the wear of materials for tools for cutting machines.Yesterday, I was reading wikipedia page about electrical resistivity and I thought if it might be possible to evaluate the estimate the material loss of the tool through the measure of electrical...
  42. J

    Is there a loss of electrons in a generator circuit?

    I have studied electrical engineering, and I've seen some discussion about this question in general. However, the question that I have on potential loss of electrons in a generator circuit is a little more specific. Is the energy that is transferred/generated purely produced by the movement of...
  43. B

    B How to calculate the gain or loss percentage in short sell?

    A stock, in the first year, cost 128 dollars; in the second, cost 64... D - Price 1 - 128 2 - 64 3 - 32 4 - 16 If I buy 100,000 dollars of this stock @ 128 dollars / share, so, in the second year I will lost 50,000 dollars (50% of 100K). In the third... ok, ok, easy... When I buy stock, my...
  44. H

    What is the grid loss problem for fusion?

    Hello, I would like to ask for a definition the grid loss problem for fusion in inertial confinement fusion methods using fusors, and what it involves. Also, it was to ask what the main solutions being currently researched are, as it is very difficult to find papers on this field. Many thanks...
  45. A

    Understanding pipe ''head loss''

    Homework Statement I am trying to understand a problem that I made for myself (although this is based on other problems I've encountered). We have a tank (reservoir) 2.9534 m in height and a head loss of 2.88 m from beginning to end; the loss is due to friction etc. There is discharge to...
  46. Gary Weller

    Is there permanent size loss in metals from contraction?

    I install automatic pool covers for a living. The tracks that our cover rides on are composed of extruded anodized aluminum. These tracks come in 22' lengths. Usually there is more than one section of track, set end to end, on a given side of the pool. We drill and anchor these sections to...
  47. danihel

    B How does black hole merger cause loss of mass?

    I’ve heard that the black holes that merged together and were the source that triggered gravity wave detector, have lost three solar masses. I understand to a very limited degree the basic notion of energy conversion like is the case in nuclear fusion/fission, annihilation, chemical energy...
  48. A

    Calculation of heat loss by Degree C/minute.

    Hi i was thinking about how to calculate the temperature lost by Degree Celsius per minute and was wondering if you had the surface area of the object, its initial temperature, a constant flow rate of air around the object and probably also need some coefficient of heat loss based on the...
  49. Greg Bernhardt

    Stopping door heat loss with curtain

    I got an original side door from 1922. Needless to say it's all warped and dented around the sides. My best attempts to weatherize have failed. It's extremely drafty. Various weather strips have not worked and the storm door helps very marginally. I was about to give up and just plastic wrap it...
  50. B

    Singular pressure loss in a bend

    Hello everyone, I have difficulties estimating the singular pressure drop coefficient of a 90° bend of radius ratio 1.5, based on literature. For example, if I look at the Idel'Cik book, I find a value of 0.17. If I take a different reference: "TRW Fluid Designers Handbook", I get a coefficient...
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