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    Academic journals practices

    This can be a general thread that others may discuss their experiences. I have a question to which I couldn't readily find an answer: What does it mean when the editor(in-chief, if it makes a difference) sends you papers to review often, like once a month? The editor even sends that person two...
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    Iron and steel industry flows: A question

    Hello, I have a general question for the flows of steel-making up to the casting process. Is the general flow depicted by the image correct? This specific process relies on natural gas reforming to produce H2, which is then used to reduce iron ore. Are there any corrections that I have to make?
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    Editors of academic journals - Question

    What does it mean when a journal constantly changes managing editors for a revised submission? A journal initially handed down a minor revision for a paper. I became a reviewer after the revision was complete, and saw many shortcomings or mistakes, so I recommended a major revision. It's been a...
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    The merger of engineering and economics

    I couldn't fit it in the title, but I think the merger of engineering and economics is going to be important going forward. I feel most economists look down on engineering economics (just thinking of variable/fixed operational costs and investment costs, etc), and most engineers think that...
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    What's the general perception of the International Journal of Greenhouse Gas Control

    The international Journal of Greenhouse Gas Control. It has an Impact Factor of around 4, but what's the perception? Is it respected? Is it considered a good journal? There isn't a qualitative judgment online. My boss seems to look down on it, but it has a good impact factor.
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    Solving the heat equation with complicated boundary conditions

    Hi, it is easy solving these PDEs with the idealized homogeneous BCs they throw out in class, but I am having some difficulty solving the transient problem posed in the images below. I have tried working through it, but I don't have confidence in the result. I overlook the solution when the...
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    MATLAB Matlab - ADI Method Code

    Hi, I've been having some difficulty with Matlab. I keep getting confused with the indexing and the loops. To set up the code, I am trying to implement the ADI method for a 2-D heat equation (u_t=u_xx+u_yy+f(x,y,t)). I have Dirichlet boundary conditions on the left, upper, and lower...
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    Ideal Vortex

    I need to find the circulation for a flow in a pipe. I'm using the velocity in the angular direction (cylindrical coordinate system). Am I right in thinking that an ideal vortex is one where there is no vorticity? That would mean there is no circulation. It's strange, because the velocity is...
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    Deriving Compatibility Conditions for Differential Equations

    I'm not sure if my thought process is correct. I basically looked at 1-D and 2-D self-adjoint problems to see what conditions were imposed on them, and tried to translate over to this problem. Can somebody tell me if I'm correct? Or at least have the right idea? I have my work linked below to...
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    Index Notation

    I have a general question about index notation. For an arbitrary quantity, a, "a" denotes a scalar quantity. "a_i" denotes a vector. "a_ij" denotes a 2nd-order tensor. So, if I have something like "a_i*e_ij*b_j" Would this be like multiplying an nx1 vector, an mxm matrix, and an Lx1 vector...
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    Solving a System of PDE's Using Maple

    I am solving a coupled system of non-linear PDE's. What am I doing wrong in the procedure? It says, "Error, (in pdsolve/sys) too many arguments; some or all of the following are wrong: [[k(x, y), p(x, y)], {diff(k(x, y), y) = 0, diff(p(x, y), y) = 0}]". I am trying to imposed zero boundary...
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    Has Anybody Been in this Situation Before? (Masters Thesis/Advisor)

    I'm working on a project with a professor for my MS. It's computational, and I am currently stuck at a critical point. I can physically justify some assumptions and get the model to work, but I can't do so mathematically. They would be mathematically arbitrary. I'm working to resolve this...
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    Differentiation Variable

    I'm working out some problems, and I'm ending up with a term similar to the following: du/d(y/u) I'm differentiating with respect to y/u. Both y and u are variables. How can I divide that up to represent differentiation with just one variable (Even if it means expanding the term)? Is it...
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    Turbulent Natural Convection with Condensation

    Hello, I'm thinking about a natural convection problem where you have turbulent flow on a vertical wall. It's compressible flow, and it's a two-phase problem. You have two boundary layers, one for the air-vapor mixture, and one for the condensate. The question I'm pondering is this...
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    Fortran Why Doesn't Fortran Recognize Small Numbers?

    We're not talking very small. Is it the compiler? I'm using gfortran. An example would be: f(y)=1E-5*(y**3) For f(40), that should be 0.64. When I compile and execute, however, it displays 0's. If I make the coefficient 1, the result does come out to be correct. I have an old...
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    COMSOL Multiphyiscs

    Homework Statement How do I set a slope-matching condition in COMSOL? Homework Equations u1x=u2x. The Attempt at a Solution I have used the Dirichlet BC type. I have multiplied and divided by n, the number of equations, on either side of the boundary.
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    How is Finite Difference Method?

    I'm going to take a finite difference linear and non-linear PDE course next semester. I'm wondering how enjoyable the material is, and how difficult it may be. I'm actually looking forward to the fact there may only be one test throughout the semester, if any, and it's a mid-term. The rest of...
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    Fortran I'm Having a lot of Problems with Fortran (77)

    I'm new to this language, and my programming experience is limited (I've only done Assembly). My issues do not necessarily lie in the coding itself, but in the compiling and building. I'm using Eclipse, on which I installed Photran. The syntax recognition and formatting of the GUI is very...
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    1D COMSOL Domain Implementation

    Hello, This is the first time I'm using COMSOL on a problem where I have multiple subdomains within the domain. Previously, I have only been using one domain/one set of equations/Two global sets of BC's. I've been having a hard time thinking of a solution to my problem. I have 3...
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    Shear Stress for Fluids

    Homework Statement I have an empirically-derived equation for the shear stress of a fluid on a surface, given by the equation below. I am supposed to take the derivative of density with respect to distance, and I must use this equation to find an expression for density. Delta = Boundary...
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    Partial Density

    Homework Statement I am trying to integrate the momentum equation in the Navier-Stokes equations, and I need to make sure I have the density formulation correct. I'm unsure of my work because a lot of the terms in the end are canceling out. It's a two-phase mixture, so the sum of the partial...
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    Really complex function to integrate

    Hello, I have a really complex function to integrate (not homework), and I was wondering if there is any software application that can handle it. I have tried MathCAD and Maple, but both can't perform it. I don't think I can do it by hand, with all the integration by parts and expansions...
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    Showing That the Modified Bessel Function of the First Kind is a Solution

    Hello, I am in the process of showing that the modified Bessel function, I_v(x), is a solution to the modified Bessel equation, x^2*y''+x*y'-(x^2+v^2)*y=0 I have differentiated the MBF twice and plugged it in to show that the left hand side is in fact 0. After a good amount of work...
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    Question About Mass and Mass Flow Rate Relations

    Mass is the product of density and volume. Mass flow rate is the product density, velocity, and cross-sectional area. (It's the derivative of mass with respect to time.) Bare with the syntax please... Looking at a sphere within a larger sphere, the volume of the difference is...