https://community.wolfram.com RSS Feed for Wolfram Community showing questions tagged with Material Sciences sorted by most viewed. https://community.wolfram.com/groups/-/m/t/441203 (*Axialsimmetric Problems) I write the physics laws,There is shaft mounted with rim for interference with a flywheel. The three costant C1,C3,C4 I find them by imposing the boundary conditions: I don't know because Mathematica give me this error,that i've published in the picture. I try the solution exact of the three costant C1,C3,C4....... Thank you and good day!!! Giovanni Ferdina 2015-02-12T15:48:37Z https://community.wolfram.com/groups/-/m/t/171121 Many sub-fields of materials science are interested in understanding interfaces: if I deposit a layer of germanium on top of silicon, how is the germanium lattice distorted?  A challenge for any cellular automata-like model of this process is that the size of the lattice/grid changes: silicon atoms aren't the same size as germanium atoms.  Much searching of the Wolfram site has found a few CA models of deposition, but none that incorporates this somewhat critical aspect.  So...  Is it even possible to build a cellular automata with non-uniform cells, or does that put me into more traditional modeling domains?  More generally, any pointers to people using Mathematica to model crystal growth? At this point I'd be interested in any level of sophistication, from hard spheres all the way up, simply because there doesn't seem to be a whole lot out there.  Thanks!  Katherine  Katherine Derbyshire 2013-12-14T20:55:23Z https://community.wolfram.com/groups/-/m/t/520537 I am a materials scientist studying the microstructures of alloys of tungsten, iron, and nickel processed using liquid-phase sintering. The alloys produce microstructures full of spheroid tungsten particles, some of them connected to other particles, within a matrix of iron-nickel alloy. In places where two particles connect, they form a "neck" between them, which appears as a solid-solid boundary extending in two directions to "triple-points" where the solid-liquid boundaries of the surfaces of the respective connected particles both intersect. The angles formed by the respective orientations of the three intersecting boudaries are known in literature as "dihedral angles" and are indicative of the respective energies of the boundaries that form them. The relative differences in boundary surface energies has dominating effects on the evolution of the microstructures of these alloys through the processing/sintering time, and so it is important to have tools that can take automated measurements of them as they appear in digital micrographs so that large samples of measurements may be accumulated to provide a large sample and more accurate estimates of the population statistics. I have developed Mathematica code that will binarize the grayscale images that I have, and refine these binary images so that they closely represent the shapes and contours of the surface boundaries of particles. Also, I have used the ImageCorners operation to identify the triple-points in the images with good success. This leaves me with the task of taking measurements of the angles at these triple points. Most of the discussion that I have seen so far involves measurements of angles at "branches" where vertexes are identified and numbered and then used to find the angles using the "VectorAngle" operation. This approach may work, but the closest that I have come to isolating branches in my images is by using the Perimeter function to make an image of just the pixels at the particle boundaries and their intersections. This leaves me with a bit of code left to do, and I am just starting out in Mathematica and not quite up to that task yet. Any help is appreciated. Phillip Green 2015-06-30T00:28:07Z https://community.wolfram.com/groups/-/m/t/125080 So I was wondering if it's possible to use Mathematica for the following: I have an arbitrary shape that I would like to cut out from a big piece of square material of fixed dimension. I was wondering if Mathematica can help to calculate the number of such arbitrary shapes whose dimensions I will specify that can be cut out from the bigger piece of material? jtherlio 2013-09-17T09:18:52Z https://community.wolfram.com/groups/-/m/t/134057 Hi Everybody, I just stumbled upon a problem and cannot move forward, so I'd kindly appreciate your expertise and help. I am trying to perform a simultaneous fit of functions, which are a solution of a set of differential equations. One of the parameters of the fit enters also as a parameter for a starting value in NDSolve ad thus I get an error (initial condition being non-numeric). The fitting is performed by constructing and minimizing a function (a sum of squares). Here's the code below. The function is defined here:[mcode]ClearAll[Ae, A2e, Ah, A2h, DE, T]; Ts = 10; funk[Ae_?NumberQ, A2e_?NumberQ, Ah_?NumberQ, A2h_?NumberQ, DE_?NumberQ, Tx_?NumberQ] := Block[ {uu, nx, nd, nxp, nxm, n2x}, uu = NDSolve[{ nx[T]' == -Ae nx[T] - Ah nx[T] + A2h nxp[T] + A2e nxm[T] + Exp[-(DE/(2 kbev T))] nd[T] - Exp[DE/(2 kbev T)] nx[T], nd[T]' == -Ae nd[T] - Ah nd[T] + A2h nxp[T] + A2e nxm[T] - Exp[-(DE/(2 kbev T))] nd[T] + Exp[DE/(2 kbev T)] nx[T], nxp[T]' == -Ae nxp[T] - A2h nxp[T] + A2e n2x[T], nxm[T]' == -A2e nxm[T] - Ah nxm[T] + A2h n2x[T], n2x[T] == -A2e n2x[T] - A2h n2x[T], nx[Ts] == Exp[-(DE/(2 kbev Ts))], nd[Ts] == Exp[DE/(2 kbev Ts)], nxp[Ts] == nx[Ts], nxm[Ts] == nx[Ts], n2x[Ts] == nx[Ts]/2}, {nx[T], nd[T], nxp[T], nxm[T], n2x[T]}, {T, 10, 100}][[1]]; {nx[T], nxp[T], nxm[T], n2x[T]} /. uu /. {T -> Tx} ];[/mcode]This is data (for tests only):[mcode]osT = {10, 25}; daneX = {1, 0.8}; daneXp = {0.9, 0.3}; daneXm = {1, 0.8}; dane2X = {0.5, 0.1};[/mcode] And this is the function to be minimized:[mcode]sse[Ae_, A2e_, Ah_, A2h_, DE_] := Apply[Plus, (funk[Ae, A2e, Ah, A2h, DE, osT][[1]] - daneX)^2 + (funk[Ae, A2e, Ah, A2h, DE, osT][[2]] - daneXp)^2 + (funk[Ae, A2e, Ah, A2h, DE, osT][[3]] - daneXm)^2 + (funk[Ae, A2e, Ah, A2h, DE, osT][[4]] - dane2X)^2];[/mcode] I can evaluate sse, but running FindMinimum results with the error:NDSolve::ndinnt: Initial condition 0.+0.5` 2.71828^(-580.248 DE) is not a number or a rectangular array of numbers. Any ideas would be much appreciated, Cheers EB Elwood Blues 2013-10-03T11:28:36Z https://community.wolfram.com/groups/-/m/t/410320 I have a problem with NMinimize function that does not seem able to use the 8 processors of my machine (16 kernels with hyperthreading) to calculate the function to be minimized. If I calculated for given values of the parameters the same function Mathematica uses several processors. To do that I use ParallelTable function. But when I use NMinimize my computer use only one processor. here is the function to minimize : func = Total[ ParallelTable[(mmoyen0[datamhtcor[[j, 1]], datamhtcor[[j, 2]], datamhtcor[[j, 3]], -10, 0., 2, 2, 2] - datamhtcor[[j, 4]])^2, {j, 1, Length[datamhtcor]}]] *where mmoyen0 is another function which diagonalize matrices. It depends on variables (b, db, t) and parameters (dist,ee, gx,gy,gz) datamhtcor are a list of experimental data {magnetic field B, small variation of B,Temperature, axial anisotropy, rhombic anisotropy, Lande factor x, Lande factor y, Lande factor x} SetAttributes[mmoyen0, Listable] mmoyen0[(b_)?NumericQ, (db_)?NumericQ, (t_)?NumericQ, (dist_)? NumericQ, (ee_)?NumericQ, (gx_)?NumericQ, (gy_)?NumericQ, (gz_)? NumericQ] := Module[{i, mm}, mm = Table[ msurh0[b, db, t, dist, ee, gx, gy, gz, cossintetaphi[[i, 1]], cossintetaphi[[i, 2]], cossintetaphi[[i, 3]]], {i, 1, Length[cossintetaphi]}]; Total[mm, {1}]]/Length[cossintetaphi]; msurh0 is the following function msurh0[(b_)?NumericQ, (db_)?NumericQ, (t_)?NumericQ, (dist_)? NumericQ, (ee_)?NumericQ, (gx_)?NumericQ, (gy_)?NumericQ, (gz_)? NumericQ, (cos_)?NumericQ, (sincos_)?NumericQ, (sinsin_)? NumericQ] := mx20[b, db, t, dist, ee, gx, gy, gz, cos, sincos, sinsin] sincos + my20[b, db, t, dist, ee, gx, gy, gz, cos, sincos, sinsin] sinsin + mz20[b, db, t, dist, ee, gx, gy, gz, cos, sincos, sinsin] cos and mx20 is mx20[(b_)?NumericQ, (db_)?NumericQ, (t_)?NumericQ, (dist_)? NumericQ, (ee_)?NumericQ, (gx_)?NumericQ, (gy_)?NumericQ, (gz_)? NumericQ, (cos_)?NumericQ, (sincos_)?NumericQ, (sinsin_)? NumericQ] := Module[{kk, nak, \[Beta], i, som1, som2, en1, en2}, nak = 8.314282370753999 10^7; \[Beta] = 4.66864374 10^-5; kk = 0.695054; (*calcul de la dérivée suivant l'axe x*) som1 = 0; som2 = 0; en1 = Sort[Eigenvalues[ matx20[b, db/2, gx, gy, gz, dist, ee, cos, sincos, sinsin, \[Beta]]]]; en2 = Sort[Eigenvalues[ matx20[b, -db/2, gx, gy, gz, dist, ee, cos, sincos, sinsin, \[Beta]]]]; som1 = Total[Exp[-en1/(kk t)]]; som2 = Total[Exp[-en2/(kk t)]]; nak t (Log[som1] - Log[som2])/db/5585]; To calculate the function func Mathematica use several processors but when this function is used in NMinimize, Mathematica use only one processor Do you have any suggestions to force Mathematica to use several processors to calculate the func function. It is really a pity to see that Mathematica only use 6% of power of my computer (I have 16 possible kernels on my machine) Regards Yves Yves Journaux 2014-12-19T13:58:53Z https://community.wolfram.com/groups/-/m/t/106133 I'm attempting to fit a model to my numerical dataset.  Unfortunately, the model contains rather complicated integral that cannot be solved analytically, but it can be solved numerically. Since the fitting is a numerical calculation, Mathematica should be able to find values for my fit parameters?  My attempts have been unsuccessful.  I either get errors saying it can't do the numerical integration because some of the parameters are not numbers, or I get the cell evaluating for days with no results (presumably because it's trying to find an analytical solution during each iteration of the fit).  My Mathematica knowledge is limited to just the basics. I've tried a few combinations of Integrate/NIntegrate and FindFit without any luck. I'm sure someone out there can help me. Here are some details: Data is intensity values in 2-D: {x, y, intensity}. [mcode]model = S0*Integrate[Exp[(-\[Gamma])*(Sin^2)[\[Theta]]]/(1+(a*(x-x0)*Cos[\[Theta]] + b*(y-y0)*Sin[\[Theta]]*Cos[\[Phi]])^2),{\[Theta], -(Pi/2),Pi/2}, {\[Phi], 0, 2*Pi}][/mcode]The parameters to fit are S0, gamma, a, b, x0, y0.  Theta and Phi will be integrated out of the model... assuming the numerical integration will be done.  All parameters and variables are real numbers. S0, gamma, a, and b, are all positive numbers. Do you have any ideas on how to execute this fit? Nick D 2013-08-22T20:38:00Z https://community.wolfram.com/groups/-/m/t/398240 Dear friends I need to define and plot a 6-piecewise function but the software only accept 3 and when i try to add more, the font color changes to red and the program does not execute. Can anyone help me? All the best Philip Majnooni 2014-11-28T11:39:53Z https://community.wolfram.com/groups/-/m/t/908230 Hello! I'm trying to make a table of "Polymers" and get the following Data: "Name", "MolecularFormulaDisplay", "Resistivity" "DielectricConstant". I also plan to sort the table by DielectricConstant and filter Missing data. I just started as a Research Assistant at school, so I'm pretty new here. This is what I have so far, and I'm getting only Missing[NotAvailable]. I don't know whether the filter isn't working or DielectricConstant is inexistent for the class "Polymers". Short[DeleteCases[ Table[ChemicalData[#, prop], {prop, {"Name", "MolecularFormulaDisplay", "Resistivity", "DielectricConstant"}}] & /@ ChemicalData["Polymers"], {_, _, _, _Missing}], 4] vals = Table[ ChemicalData[#, prop], {prop, {"Name", "MolecularFormulaDisplay", "Resistivity", "DielectricConstant"}}] & /@ ChemicalData["Polymers"]; Text[Grid[ Prepend[vals[[1 ;; 10]], {"Name", "MolecularFormulaDisplay", "Resistivity", "DielectricConstant"}], Frame -> All, Background -> {None, {{{LightBlue, White}}, {1 -> LightYellow}}}, Alignment -> Left]] Henrique Padilha 2016-08-19T03:46:16Z https://community.wolfram.com/groups/-/m/t/572327 Hi, I have a data set (X, Y) such that Y = f(X, a, b). I want to fit the data point with this equation to determine the values of a and b. I am having following issues - 1. First, I want to know how to insert a table with 2 columns having values (x1, y1), (x2, y2).... with headers "X" and "Y" known to mathematica, as only then I can use a function like FindFit with X and Y defined. 2. If some other method could be easier, please let me know. Here is a parallel example to explain my problem - There is a (X, Y) data set (2, 5), (4, 9) (5, 16), (7, 28) ..and so on. i know that Y = aX+b. Now I want to fit the data point to determine the values of a and b. thanks a lot S G 2015-09-28T17:48:11Z https://community.wolfram.com/groups/-/m/t/606280 Hi guys, I am working with a theoretical civil engineering work and I am encountering a problem when I want to calculate the product of two DiracDelta under the integration, However according to a published scintific paper, the product of two DiracDelta could be considered as a constant multiply by the diracdelta, so that mathematica is able to calculate the integration. But the problem is the calculation of the integral of the product of the derivative of two diracdelta, and unfortunately there is no suggestion for substitution. Because mathematica does not yield anything if you try the above expression under integral. I would be eternaly greatful for any suggestions. Mohsen Rezaee 2015-11-05T11:07:12Z https://community.wolfram.com/groups/-/m/t/501859 I am trying to set the default directory in FileNameSetter. If I simply do:`FileNameSetter[$UserDocumentsDirectory]` hitting the Browse button will start in the the defined directory, but in the following code: SetDirectory[ToFileName[{$HomeDirectory, "Desktop"}]]; DialogInput[{filename = ""}, Column[{"Either type your file name (in quotation marks and with the \ file extension) or browse for your file:", InputField[Dynamic[filename], String, FieldHint -> "Enter your file name"], FileNameSetter[Dynamic[filename], "Open", {"text files" -> {"*.txt"}}, Method -> "Preemptive"], DefaultButton[DialogReturn[filename]]}]] I can't figure out how to add a default directory option (in this case I would like: ToFileName[{$HomeDirectory, "Desktop"}]). Anywhere I add it seems to mess up the definition of FN[ct] and/or filename. I would appreciate any advice you may be able to provide. Thanks, Matty Matty Mookerjee 2015-05-21T19:49:23Z https://community.wolfram.com/groups/-/m/t/548980 Hello all, I am trying to solve time dependent coupled differential equations with know initial conditions. I am just a beginner in terms of coding so can someone please suggest the best possible function that can be used for this purpose? I am currently trying NDSolve and NDSolveValue to see if I can get any reasonable solution. Also, I would really appreciate if someone can give me an example of this kind. Thanks a lot! Sid D 2015-08-18T15:56:04Z https://community.wolfram.com/groups/-/m/t/1126696 I am trying to solve the Heat Equation in 2D for a circular domain and I used the example attached, however, for some reason I do not get any answer from it, and in principle, it seems that I am following the same steps as in the original document from wolfram tutorials. Any help will be much appreciated. I am using version 11.1.1 David Quesada 2017-06-23T17:34:18Z https://community.wolfram.com/groups/-/m/t/546253 I am curious with the right sets of data in place from a number of sources would Mathematica be able to help (along with additional algorithms and such) help police in the aid of finding missing persons from around the world?(using real time data and other data inputed by search and rescue etc) eric caron 2015-08-12T06:30:36Z https://community.wolfram.com/groups/-/m/t/307233 Hey Wolfram Community, I would like to use Mathematica's image processing functionality to visualize the difference between these two images. Here's what's going on here: I am heating the pins, and the hot air rising from the pins is distorting the randomized background. My goal is to visualize the air plumes resulting from heating the pins. Thus far I have tried to use ImageFeatureTrack on the two images, which gives me a list of points, but I don't know how to turn these points into a meaningful visualization on top of the original image. My ideal visualization would be lines drawn from their position in the first image to their distorted position in the second image, perhaps colored as a function of their length (i.e. areas with more distortion would have a more intense color). I've spent about two days watching tutorials and to learn the Wolfram Language, but I'm not able to figure out which functions to use, and I keep getting errors about data types passing from one function to the next. Even an explanation of the right strategy for achieving this would be really helpful. Attached is a notebook with the two images, and my attempts so far. Thanks, Alexander Alexander Jacobson 2014-07-29T19:55:16Z https://community.wolfram.com/groups/-/m/t/551131 Hello all, If I have a DensityPlot of a function, how can I extract the data in .txt format? Here is a simplistic version of what I have: F = x^2 + y^2; DensityPlot[(F), {x, -20, 20}, {y, -20, 20}, ColorFunction -> "Rainbow", PlotPoints -> 100, PlotRange -> Full, PlotLegends -> Automatic] Thanks a lot! Sid D 2015-08-21T16:38:18Z https://community.wolfram.com/groups/-/m/t/1021169 I'm currently trying to solve a mass balance useful in metallurgical processing. There are 4 ingoing streams (streams "c", "f","h" and "o") and 3 outgoing streams ("m", "e" and "s") and 5 chemical elements: Cu, Fe, S, O, and Si. The components are written as moles/100g of the respective stream. The compositions of streams "m", "s", "o", "f" and "h" are known, but the Fe, Si and O content of stream "e" is unknown. The O content of it can be obtained by charge balance, given that the oxidation states are: Cu =+1, Fe= x (+2<x<+3), Si=+4, S= -2, O = -2. Note: The vector "A" is the vector of atomic weights, useful because the dot product of it and the composition vector of any stream must be 1 (i.e the sum of mass % of all components must be 100%). The factor "R" is the (known) iron/silicon ratio of stream "e" The equation I am trying to solve is the following lineal system: Fee = Sie*R Oe = (Cue*1 + Fee*x + Sie*4 - Se*2)/2 m = {Cum, Fem, Sm, Om, Sim } e = {Cue, Fee, Se, Oe, Sie } c = {Cuc, Fec, Sc, Oc, Sic } f = {Cuf, Fef, Sf, Of, Sif } h = {Cuh, Feh, Sh, Oh, Sih } s = {0, 0, Ss, 2 Ss, 0 } o = {0, 0, 0, Oo, 0 } A = {ACu, AFe, AS, AO, ASi } Solve[{Mm*m + Me*e + Ms*s == Mc*c +Mf*f +Mh*h +Mo*o, Mm + Me + Ms == Mc +Mf +Mh +Mo , e.A == 1}, {Mm, Me, Mf, Mh, Ms, Mo, Sie}, Reals] Unfortunately, the program does not run, even after a week of trying to symplify/rearrange the equations. I cannot find the mistake, it should run as a system of 7 equations with 7 unknowns. Perhaps there is some (implicit) unknown variable or equation redundant or missing in the system of equations. The unknown variables should be the following: Mm, Me, Ms, Mo, Mf, Mh = masses Mi of the streams "m", "s", "o", "f" , "h" and "e" Sie = silicon concentration in stream "e" Thank you in advance for your help, Alberto Alberto Silva Ariano 2017-02-25T23:21:42Z https://community.wolfram.com/groups/-/m/t/245435 The emissivity of Nifethal doesn't find it. It's weird because the emissivity of Kanthal can find it. When I search the emissivity of Nifethal says [b]'data not available'[/b] [b][/b]It would be great to see the result in the near future because I'm trying to search it and I haven't found it yet. Thanks. Kleiber Osoga 2014-04-30T01:32:36Z https://community.wolfram.com/groups/-/m/t/78859 Hello World; I have been trying to make an animation for my research. I have a bunch of prototype output files so called output1.txt         output2.txt output3.txt output4.txt ...etc When I feed those files one at a time, I get stay images. What I would like to do is feed all the files in order in every 0.5 seconds, so I will have 2 frames per second but I cannot figure out how to update the file sequences in mathematica.This is what I have so far and I am looking for the coding to update the files automatically. [mcode]Graphics3D[<< output1.txt] Graphics3D[<< output2.txt] Graphics3D[<< output3.txt] Graphics3D[<< output4.txt][/mcode]If you have any ideas, please let me know. Thank You. -P. Aung P Aung 2013-07-26T20:59:42Z