Grid Definition and 222 Threads

  1. ergospherical

    Python How to store a large data-set in a "grid" in Python/NumPy

    Say I have n parameters X1, X2, ..., Xn, and to each "grid-point" X = (X1, X2, ..., Xn) I want to associate a value f(X). So in the end I will have a structure like an n-dimensional matrix. Assume this data-set is going to be very large, i.e. each parameter Xi ranges over hundreds or thousands...
  2. ab200

    What Am I Doing Wrong in Calculating Potential on a Grid?

    Looking at the image, I see that due to symmetry, the bottom-left negative charge and the bottom-right positive charge cancel out, leaving me with a triangle around the center. I'm not entirely sure how to solve for potential at the origin specifically, but I believe that the potential energy of...
  3. D

    ESA's Dual Stage 4 Grid Ion propulsion

    I have found remarkably little information about ESA's Ion Drive in collaboration with Australia: https://en.wikipedia.org/wiki/Dual-Stage_4-Grid https://www.esa.int/gsp/ACT/doc/PRO/ACT-RPR-PRO-IAC2006-DS4G-C4.4.7.pdf Reference...
  4. D

    Is the Dual-Stage 4 Grid Ion Drive the Key to Faster Space Travel?

    My post was removed originally about a designed based on this new engine. I don't know what specific forum rule I broke, I read the entire thing. But I am posting a new threat to ask about the validity of this specific technology. I am asking because there seems to be zero media coverage of it...
  5. BiGyElLoWhAt

    3d plot of interference from 2 wave sources with 2d grid surface

    Desired output similar to image, but without the objects and with better wave interference: I tried plugging the following into wolfram (I specifically want the values to be adjustable): plot z= H*e^(-m*sqrt((x-a)^2+(y-b)^2))*sin(k*(x-a)+k*(y-b) -w*t) +...
  6. James1238765

    I How to do algebra on the Kitaev toric code grid?

    The toric code is a basic computational model as follows: There are 2 operations that can be performed, A and B, on this grid. To compute the value A at each point on the grid, we transform the raw values at each dot (located in between two vertices) according to some predefined operators...
  7. M

    Microsoft Excel background grid color default reverts

    Basically, microsoft excel always has white background cells, and I'd like it to be a different color. Here's what I've tried: I configured the below registry value in my Windows 11 user profile to change the default window color from 255 255 255 (i.e. white) to 192 192 192 (i.e. a not so...
  8. G

    Do personal PV panels make sense considering the grid "cleanliness"?

    Hello Physics Forums! It is only my second post here, so sorry if I am not perfectly following the rules... We were wondering with some colleagues a few hours ago, what is the threshold where PV panels are adding a carbon footprint to the electricity generated on the grid considering the...
  9. shivajikobardan

    HTML/CSS How to build this using CSS Grid?

    I built these using CSS Grids very easily. Source: https://www.quackit.com/css/grid/tutorial/create_a_website_layout.cfm But the first one is different and requires different logic. I can't use grid-template-areas there for whole grid. This is my code for the last layout(I've to edit height...
  10. S

    Misc. What are grid sheets used for on work tables?

    What are these sheets with grids and angle references called, that people use on their work tables?
  11. Arman777

    Creating a grid type 3D data array from data points

    I have a 3 data column ##(X, Y, Z)## ranges from ##(min, max)##. For example, ##X = (0, 5)##, ##Y=(0, 3)##, ##Z=(0, 2)##. By using them I need to create a numpy array in the form of ##[(0, 0, 0), (0, 0, 1), (0, 0, 2), (0, 1, 0), (0, 1, 1), (0, 1, 2), (0, 2, 0)...]## So in total there will be...
  12. JD_PM

    How to determine the minimum grid length | Numerical Plasma Physics

    Summary:: I am learning particle-in-cell (PIC) python 3X code. PIC currently represents one of the most important plasma simulation tools. It is particularly suited to the study of kinetic or non-Maxwellian effects. I am learning particle-in-cell (PIC) python code. PIC currently represents one...
  13. Y

    Considering Earth ground vs floating ground in off grid solar

    Context: I'm building an off-grid, 100% solar powered home. I have a 12 kw solar array wired up to a Sol-Ark inverter and a Fortress 18.5 kwh lithium battery. Question: What is the ideal grounding/earthing scheme? Additional context: where I'm building, there is currently no requirement that...
  14. M

    Turbulence of square fractal grid

    Hi all, Whats the significance/application of square fractal grid turbulence studies?
  15. P

    Calculating Radiation Pattern for a grid of two rows of dipole antennas

    Although problem says sketch, what I really want is the formulae by θ for the radiation. After trying this for a while I cheated and looked at the solution. I still can't figure out the steps on how to get to the solution. the answer is: What I tried: I'll assume that the intensity from a...
  16. jim mcnamara

    What can we learn from Texas' power grid failure?

    https://www.nbcnews.com/science/environment/one-texas-storm-exposed-energy-grid-unprepared-climate-change-rcna289 The link above is an opinion piece that discusses the possible lessons from the experience in Texas. FYI: This was a textbook system wide grid failure, caused by off the charts...
  17. anorlunda

    Grim Day on the Texas Power Grid

    This is an enormous failure, comparable to the "Great Northeast Blackout of 1965". Rolling blackouts are being imposed at a time when millions of residential customers need home heating. The oil refineries shut down. Expect gasoline/diesel shortages and price spikes nation wide in a few days...
  18. BWV

    Exploring the Possibility of 100% Renewable Grid w/ Super Power

    Interesting report on the issues and viability of a 100% wind / solar / battery grid. https://www.rethinkx.com/energy#energy-download The idea of 'super power' as they term it - the large surpluses generated during peak times for wind and solar generation is one of the more interesting aspects
  19. cnh1995

    Is the Indian National Power Grid in danger?

    As COVID-19 is growing exponentially worldwide, a 21-day lockdown is going on in India since 25th March. In this period, only essential services will remain open. To boost the morale of employees working in these essential services, Indian PM had asked all the citizens to show their gratitude by...
  20. Avatrin

    Parametric distance of a line in a grid (Line Integral Convolution)

    Hi, the above image is from the Line Integral Convolution paper by Cabral and Leedom. However, I am having a hard time implementing it, and I am quite certain I am misreading it. It is supposed to give me the distances of the lines like in the example below, but I am not sure how it can. First...
  21. T

    What is the difference between Grid and Cloud Computing?

    Good Morning I have googled this issue (the difference between Grid and Cloud computing, as per subject line), but I find many of the definitions overlap each other and leave a lot of ambiguity. A lot of the examples focus on manipulation of data (versus independent processes). But BEFORE I...
  22. S

    A According to Wilczek, how does quantum mechanics arise?

    According to Nobel laureate Frank Wilczek, the universe emerges from a Grid. This was proposed in his book "The Lightness of Being: Mass, Ether, and the Unification of Forces". He also likes the idea that the universe emerged from a state of "nothingness" (or rather, a quantum vacuum) where...
  23. tech99

    Is reducing energy losses critical for the success of hydrogen in the gas grid?

    A trial has commenced at Keele University in the UK where 20% Hydrogen is injected into the domestic gas supply. In this way it can be stored and then utilised by existing domestic burners. Can this be a quick solution to reducing domestic CO2 emissions? Or is it better to use battery storage...
  24. A

    Modeling PWR Core With Spacer Grid

    Hello everyone, i am Ali a PhD scholar i need some help regarding MCNP, i wand to model a pwr core with spacer grid but i don't know how to model spacer grid can anyone help? Regards
  25. Chandrakanth_balusa

    How is the turbine speed controlled by Grid but not by itself?

    Hello People, Greetings! i am back again with a confusing question for which I thought I could get a correct answer from here. so my question is regarding the speed of the turbine. I learned that the speed of a turbine has to be maintained constant in order to maintain generating frequency...
  26. V

    MHB Number of ways to color a grid

    Hello, Kindly, can anyone solve the following: How many combinations: 8 colors, which each can be used twice in the following grid 1 3 5 7 2 4 6 8 where a color can only appear like this 1 with 5 3 with 7 2 with 6 4 with 8 So, non-valid combinations would be 1 with 2 1 with 3 2 with 3...
  27. jakiul094

    Is It Logical to Use a Generator to Produce and Share Electricity to the Grid?

    Want to produce electricity from a generator by using the motor driven by electricity suppose 10KW. It will be for only once. When the generator is able to provide suppose 60 KVA, among them I want to share 50KVA to Grid and other 10KVA I will use to run the starter motor. Is that logically ok...
  28. Q

    Physics Is going into Smart Grid with a Physics Degree a good move?

    I have a master in Physics and I would have the opportunity to have a fixed term position in a Smart grid company. My question would be whether not having a bachelor in EE or Power engineering might be bad for future job prospect(what if I apply somewhere else) and whether or not the skills I...
  29. H

    MHB Number of ways to divide a square grid in half

    Consider a dotted square grid with $4$ rows and $4$ columns, as shown: By drawing a series of connected straight lines from dot to dot, it is possible to divide the square (which effectively has side length $3$) into two parts of equal area. One way of doing this is as shown: Other examples of...
  30. F

    I Smolyak reduced grid for three dimensions

    Hello everyone. I am dealing with a stochastic optimization problem with three sources of uncertainty and I am using generalized polynomial chaos to solve this problem. The level with I am working is 1 (l=1). There are 3^3=27 realizations to make. I want to use instead a Smolyak reduced grid...
  31. C

    Python 3d interpolation in Python using a mesh grid

    I have four arrays of data xvalues[], yvalues[], zvalues[] and wvalues[] and I want to create, from this data, an interpolated function w = f(x,y,z). Is it easy to do this in python using first a meshgrid and then calling scipy's interpolation? e.g toy set up is something like, where wvalues...
  32. V

    Electrical Designing an off grid power plant

    Hello! I have some plans that i want to share and get some feedback on before i start construction and buying parts. I have some land next to a lake that i can build a dam with head of 30m around 10000m2 and almost 50000m3. I am thinking of solar panels and wind turbine to generate electricity...
  33. L

    Connect grid tied solar inverter to DC+ Bus of VFD?

    What solutions are there to feeding a high DC voltage rated (eg 1000VDC) certified grid tied solar inverter such as a Yaskawa Solectria PVI23-480; from an alternate DC+ bus supply. For instance the 670 VDC input from a solar string; might be replaced by a a 6 pulse rectifier; (possibly from a...
  34. S

    Hydrogen to AC -- From the Fuel Cell to the Grid

    Fuel cells quickly provide electricity from H2 when switched on. But what exact steps get to Grid voltage? Are there many small inverters, and if so, how do they keep the output in step? What sort of efficiencies are there?
  35. P

    MCNP: Scoring Energy Fluence on a Radiograph Planar Grid

    Hello my friends, I would like to ask a question about MCNP. I want to score energy fluence on a rectangular radiograph planar grid. Do you know which tally should I use? I use FIR tally for particle flux. Hope you know an answer to my question :)
  36. G

    AC generator output voltage to grid question

    Hi, In a given area there are different types of power plants , let's assume they are (coal, nuclear, wind and solar) Now as I have learned most of these plants (except solar and some others) use synchronous generators as the last step between mechanical energy conversion into electricity. But...
  37. Pushoam

    What happens to waves with different polarizations in a wire grid polarizer?

    It is said that the wave whose polarization is parallel to the wire, gets absorbed by the wire. But, there is empty space between the wires. So, that part of the above - said wave which passes through the empty space will not get absorbed by the wire. So, the transmitted wave must have the wave...
  38. G

    Power grid & generator questions

    Before I begin I have to note that my last thread of this kind got heavily moderated and closed because the moderators did not like the specific way in which I was formulating my questions, so now I want to clarify and reaffirm some of what I have learned through questions without making any...
  39. M

    MHB Explore the Multiple Grid Method: Get Accurate Solution Faster

    Hey! :o I am trying to understand the multiple grid method. The idea is to use at each step different grids to solve a linear system of differential equations, so that we get the best approximation as possible. It holds that the finer the discretization, the more accurate the solution ist...
  40. F

    Evidence for global magnetic grid or pseudo science?

    In conducting research into historical accounts of Earths magnetic field, I consistently come across proposals of stable planetary magnetic grid systems; many of these theories which have apparently been developed through much time and effort. While I am unaware of any theory that cannot be...
  41. S

    How do I represent grid patterns with a dither matrix?

    Homework Statement PROBLEM STATEMENT: "Represent the grid patterns in the figure with a dither matrix." (Figure: https://www.docdroid.net/OMLUX5v/figure.pdf ) ANSWER (FROM MY BOOK): http://www.wolframalpha.com/input/?i=%7B%7B0,2%7D,%7B3,1%7D%7D Homework Equations...
  42. F

    How to Fix Error: No Periodic Zones Adjacent to Grid Interface in CFD Fluent?

    I have created a savonius turbine model with 2 blades using 3D gambit. I want to simulate the flow of air flowing so as to drive the turbine savonius spin (unsteady, incompressible). Geometry consists of 3 volume boxes (domain tunnel flow), cylinder (domain grid interface), blade savonius...
  43. Delta Force

    Chernobyl Soviet Power Grid Post-Chernobyl

    Did the Chernobyl Disaster have any major effects on the Soviet power grid as a direct result of the accident or due the retrofit and cancellation of RBMK reactors?
  44. X

    How convert a point on an X and Y grid to a angle degree?

    <Moderator's note: Moved from a technical forum and thus no template.> Hello Forum, This post is a spin-off from this post: https://www.physicsforums.com/threads/how-much-would-time-pass-between-watching-the-sun-set.925257/#post-5840279 If I have an X and Y point on a grid that represents...
  45. C

    Rolling Cylinders across a grid of bars

    Homework Statement A cylinder is placed on bars.The separation of each bar is l.The cylinder is then pulled with a force F through its center.Find the terminal velocity of the object.Assume l<<R and the ball rolls without slipping. Homework Equations 1/2 mv^2 +1/2 Iω^2 = kinetic energy Work is...
  46. H

    Energy flow in grid connected PV system

    Hello! Let's say your house is connected to the local distribution grid, and you also have a PV-system on your house that is connected to the grid (no storage): How does the equipment in your house "use" the power from the PV module, and not "from" the grid? Everything is connected, right? If...
  47. 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...
  48. ORF

    How is instantaneous power adjusted in the electrical grid?

    Hello I didn't find a similar question, but if it's redundant, please erase this thread. The instant electrical power is not constant (because of the consumption and of the production). So, how the instant power is adjusted in the electrical grid? There is a similar entry, but it has several...
  49. michiel8888

    Combining 2 grid connections ac to one

    question as grid connections are limited to 450 watts ac 220 v over her i like to combine two of these to one 900 watt grid connection?. power ac comes from the same grid (source) goes trough a meter and connects to my home system. so can i put one more meter there which is feeded from the...
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