Element Definition and 836 Threads

Hi! Does anybody here have experience with the FEMM simulation software? Its pretty popular in the engg community. I basically use it for simulating magnetostatic problems. If you do (and if this is the right forum, it is EE after all), could somebody tell me how I can do transient...

Hello, I have been trying to figure out the line element on a 3-sphere for my GR class. Problem is that I am trying to go the traditional way of finding dx, dy, dz, and dw, then regroup and find the respective unit vectors and go from there. We are given that the answer as: ds^2 = a^2(d\chi^2...

I would like to derive a relation for shear stress on a conical bore shaped fluid element. Essentially, I have flow going through a converging nozzle. I know variables in this include length of the nozzle, inlet and outlet diameters and pressures and nozzle angle. I've done a force balance on...

Homework Statement A part of one of my physics problems wants me to find the mass of iron. The atomic mass is 56 g/mol. How do you find the mass of iron?? Homework Equations Avagadros # = 6.022E23 The Attempt at a Solution I really am not sure how to solve, although it must...

[SOLVED] Access Matrix Element in Mathematica Alright, so in Mathematica you define a matrix by saying A = {{a11,12,...},{21,a22,...}} for whatever matrix you are making. How do you access a particular element of that matrix? Argh, Matlab is so much better.

How do we Calculate Temperature & Time of Heating Element Heating Wire having the following Data : SWG 16(1.63mm) Specific Resistivity = 1.45 ohms-mm-3 Density = 7.1 gm-cm-3 Resistance = 0.685 ohms/Meter Weight = 15 Gram/Meter (a)In order to Build Heating Element using the above wire for...

Heating Wire having the following Data : SWG 16(1.63mm) Specific Resistivity = 1.45 ohms-mm-3 Density = 7.1 gm-cm-3 Resistance = 0.685 ohms/Meter Weight = 15 Gram/Meter (a)Please help me in this Project to Build Heating Element using the above wire for Making 2.5 KiloWatt heating Element...

Homework Statement Obtain the temperature distribution T(x,y) of the triangular cross section, assuming constant thermal conductivity, k. The triangle is a right-isosceles triangle with the right angle at (0,0). The triangle goes "up" to a, and to the right to a, then diagonally across...

Element 18001 "reactium" Lets suppose that someone created element 18001 (although it would only last less than 1 microsecond), an alkaline metal. Noting that Cs reacts twice more vigorously than Rb and Rb twice more vigorously than K, would element 18001 be thousands of times more powerful as Cs?

i'm at a loss about how to do this type of integration. can some one show me how to evaluate the integral of (d^3)k exp[ik*(x1-x2)]/[(k^2+m^2)(2pi)^3], where "*" is the dot product between the 3 vector k and (x1-x2), which are both 3 vectors. this come from the energy equation used to get the...

Hello, I have found that in some processing cases that additional elements are added to metals which result in increased potential for smaller grain size. Does anyone know why this is so? Am I signiificantly misunderstanding the issue? Thanks, -scott

Is it possible for atoms of the same chemical element to have different chemical properties? My attempt Isotopes of an element differ from one another by the number of neutrons in the nucleus. They have same number of proton in the nuclei so they have the same chemical properties but not...

Hi, I don't know if I have posted in the right area but i read about these new super heavy elements, what are these elements and what can they be used for exactly? http://www.sciencedaily.com/releases/2004/02/040203234610.htm

hello all! If there is a circuit with only one heating element, how do we calculate the power it requires? According to the physics formula P=V^2/R, whenever you increase the resistance, the power it requires falls. However, I don't think that's right. Or is it? When R is increased, so...

This is based on the metric of the surface of a 3D sphere. A and B are constants with dimension (length)^2. Coordinates are x^0 = t, x^1 = \theta, x^2 = \phi ds^2 = -c^2AB^{-1}dt^2 + Bd\theta^2 + Bsin^2(\theta)d\phi^2 It satisfies the Einstein field equations with only one component of...

Can you convert simple current in a wire to mechanical energy with a motor? What type of equipment would this require.

What is the "field with one element"? From the definition of a field, it follows that such a thing does not exist. However a Google search reveals that apparently there is, or at least mathematicians think there ought to be, something that goes by that name. What is it? Is it called a "field"...

Homework Statement Let f(x,y,z)=x^2yz. Express f*dA in terms of u and v. The Attempt at a Solution We're given that x= u+v y= u-v z= u^2+v^2. The main problem I'm having is that I know I need to take partial derivatives in respect to u and v but I'm not sure how. I did an easier...

I'm making a coiled heating element from nichrome wire, and I was wondering how the coiling will affect the current. I have values for current needed for straight nichrome wire, but I believe coiling it will change the resistance. Thanks.

Homework Statement An element X forms both a dicholride( XCl2) and tetrachloride(XCl4). Treatment of 10.0g of XCl2 with excess forms 12.55g of XCl4. Calculate Atomic Mass of X and Identify X Homework Equations no equation needed...but urgent The Attempt at a Solution i try...

Homework Statement An element a of a ring is nilpotent if a^n = 0 for some positive integer n. Prove that R has no nonzero nilpotent elements if and only if 0 is the unique solution of the equation x^2 = 0 Homework Equations I think nilpotent means that not only that a^n = 0 for...

Hi! Anyone know what would the best INTRODUCTION / FUNDAMENTALS of Finite Element Methods oriented text be? I had read O. C. Zienkiewicz’s The Finite Element Method: Its Basis and Fundamentals, 6E, Butterworth-Heinemann … No practice problems at all, un-systematic, etc. Any advice would be...

newbie here, I've been searching many forums and cannot find the questions/answers I am looking for (close, but not quite). so, I am going to ask my question in a very specific, detailed manner. i want to use nichrome wire to make 8 heating elements. they will each be a single strand...

at least 10.. Thank You

My teacher mentioned that if an element has a neutron to proton ratio of 1.2 or higher than the element is radioactive. He also said there is on exception to this when the N/P ratio is lower than 1.2, but i didnt understand him. I cannot find this one exception in my book or on the internet. Can...

I'm working on an algorithm that finds the smallest element among a, b, and c. Here is what I have so far: Input: a,b,c Output: small; smallest element in the sequence a,b,c a = 2, b = 4, c = 3 Small = a If b < small, then small = b If c < small, then small = c Is...

I'm halfway through a question on a past differential geometry exam, and suddenly in comes a matrix g a member of SL(2,C) (where C denotes the complex numbers) Now, I can't remember how to express a general element of this group: I know the matrix must be...

Sorry I don't know how to write in symbols so I'm using Latex codes, anyway, the question is as in title: Is an element of Hom(Lambda^k(V),Lambda^(k+1)(V)) and element of End(Lambda(V))? In words, is an element of the homomorphism between k th grade exterior algebra over V and k+1 th...

Homework Statement A thin square plate of side a has one corner at the origin and two sides along the positive x and y axes. If the density of the plate is given by p(x,y) = xy show that its mass is M=(1/4)a^4 If the distance of the mass element dM = pdS from the origin is r the moment of...

might be more expensive than uranium or plutonium, but storage costs and environmental impact and anti-nuke activism might be muted if there was an isotope of any element, say an isotope of iodine, that when fissioned, gives off energy AND short-lived radioactive isotopes. so, say...

Alright. So you guys already know that the first dimension is simply a line (according to our 3-space perspective). The second dimension extends a line at 90 degrees from the first, creating a plane. Adding yet another line 90 degrees from the first two lends a cube. You may spare no great...

Does X=n? X is the element fraction in a compound, and n is the mole number of an element.

Here is the situation: We have 100w heatload coming from little die which has only 1cm^2 of surface area. We cool it with Ln2 as cold as possible (in normal atmospheric pressure) by using simple round container which is made of 99.99% copper. Let's assume that system is perfectly isolated so all...

Let R^2 be a set containing all possible rows: (a b) when using the 8 axioms to prove whether (a,b) is indeed a vector space, i have to show that there is a zero element and a unit element. Is the zero element 0? or is it in matrix form such that W = (0 0) and W is contained in R^2? Is...

Staight question : Can a radioactive element decay by emmitting more than 1 particles at once? ie. can a radioactive Uranium decay 2 beta and 1 alpha particles at the same time, or it must decay 1 particle (eg beta), itself becomes another elements and then decay further? thanks

Hi, I just saw the premier of "Birth of the Universe" on Naked Science (National Geographic) and had a couple of questions as a result, which I'm hoping somebody could answer. First, they said that the reason we have matter and no evidence of anti-matter is because when energy was converted...

A general orthogonal coordinate system (u,v,w) will have a line elemet of the form: ds^2 = f^2 du^2 + g^2dv^2 + h^2dw^2 I have done a lot of vector calculus, but for some reason I can't figure out what this means! What is a line element? I know about the differential length element and its...

Greetings. I'm a little bit confused about the dimensions of a probability amplitude in a QFT calculation. My understanding a the squared, spin averaged\summed Feynman diagram should be dimensionless. However, if we consider a decay process, say pair creation from a photon or the decay of the...

Using data collected from a spectrometer, with a diffraction grating of 100 lines/mm, I have collected a set of data. From this I have calculated wavelengths for the 1st and 2nd order lines of the three brightest visible colors, which were Blue/Violet, Green, and Orange. To complete my lab I...

im trying to produce about 270degrees celcius and have a 12v 500ma adapter i plug into the wall, I've wound the wire from a toaster round a nail, imn not getting enough heat though. I've tryed 5 small lenghts in parallel a single long piece, a single short piece... so tell me, what...

I want to derive the theory of finite element using my own understanding. With this derivation i want to understand the fea theory of rod element I call the nodes as "points" in a structure. This scenario is for a simple one dimensional displacement of points(that is the single degree of...

I am at loss to understand (from a layman's point of view...with some math-stuff, too) how an element's electron(s) can jump the quantum fence. An element, any element, as shown on the periodic table, has certain characteristics within its 'earthly' domain, the 3-D world we live in. What causes...

i start studying Finite element Methods any one who can help me on this subject, any good refrence book on this topic or other helping book.

what two measurements are made of an element using a mass spectrometer?

There is one metallic element which is normally a solid, but which will melt if you hold it in your hand. Which element is it? Is it Francium?

Could someone please recommend part values for the following components, or tell me if they do not exist: 1. differential op-amp that can source enough current to turn on a BJT and an LED, and also outputs a voltage near the +-5V inputs 2. a BJT that can withstand up to 2V across it 3. An LED...

These are the one with which I am most familiar. There are others, but these are the biggies. We use ABAQUS as well as our own proprietary methods, particularly for dynamic, large strain and nonlinear FEA. ABAQUS (HKS) - for nonlinear Finite Element Analysis (FEA) www.hks.com...

how can I find the highest element of such set: A={\sqrt[n]{n}:n\in{N}} ?

Calculate the nuclear density of Oxygen element.As I know the molar mass number is 15.9994 and the density is mass/volume how can I get the volume inorder to calculate the density?

Im stuck on this question. Isotopes of an element differ in physical properties but not chemical properties. Explain this in terms of structure. I know isotopes have the same number of protons and diff neutrons, but don't know how to answer the question. Thanks!