Section Definition and 733 Threads

Homework Statement Hi, I'm currently carrying out a computing project on Resonant Scattering and when I have identified a resonant state, I need to examine whether it has a "particular signature". However, I'm not really sure what this means... Homework Equations The differential...

Hi. I'm trying to make a pointer point to sections of a rank-2 array given by specific values of it's second index. I other words: given a table I wan't a pointer to point to specific columns, making of it a "filtered" table. The method I was trying was like DOUBLE PRECISION...

Wondering if anyone who has a passing understanding of the law would care to enlighten me about online libel law. Section 230 protects 3rd party content-providers from the claims of their users. What are implications upon an online community service whose /intent/ was to encourage...

Homework Statement I do need to calculate the mean free path for an ion with a radius of 9 x 10‐8 cm in pressures of 10‐8 Torr, 10‐6 Torr, 10‐4 Torr and 10‐2 Torr Homework Equations There are different equations I found but the most one is λ= 1/Nσ N gas number density which I do not...

Homework Statement Calculate the differential cross section for A+B---> C+D with an invariant matrix element Homework Equations See attachment The Attempt at a Solution I have no idea how to even begin this problem. The course I am taking is an undergraduate course in intermediate modern...

Homework Statement A cmedium carbon steel rod has a rectangular cross section and must cope with a tension of 29 430 Newtons . The thickness of the rod is 15 mm calculate the siz of the cross section? Homework Equations A=P/Ok [b]3. The Attempt at a Solution [/b O = UTS = 750...

Attempting Problem 1 of Arnold: ODEs, Ch. 1, section 2.2, it seems I'm not understanding something pretty basic about what he means by "the solution of a differential equation". This is the kind of equation he's talking about: \dot{x} = \mathbf{v}(x) \enspace\enspace\enspace (1) where, if...

Homework Statement Outer Integral: From zero to one dy Inner Integral: from zero to y^2 dx Function is: 3y^3 * e^(xy) Homework Equations None The Attempt at a Solution Have tried numerous u substitutions on e^(xy), but taking me nowhere. I am clearly doing something wrong...

The following question pertains to programming, but I have posted it here because I want the views of mathematicians (also of physicists and engineers), not those of computer scientists (which i already know) and I do not know how many of the former category care to look into programming...

Hello Dears! I've just registered here. It sounds nice! :smile: As I've seen in different solution manuals here in my country, there are several realizations of how to cut the section we've got, to compute the resultant shearing tension of a shear loading. For instance, as you see in the...

hi how to calculate the traces of product of Dirac matrices in QED. i want caculate crossection of process scattering in QED. a program to calculate it

Does anyone know how SolidWorks calculates the stresses for this simulation. Can anyone give me an idea, is it second moment of area? y/r = m/i? Thanks Richard.

For a direct sum of Mobius band, it is trivial if it has two linear independent nonvanishing sections. I have the following as my sections： s1=(E^(i*theta), (Cos(theta/2), Sin(theta/2)) s2=(E^(i*theta), (-Sin(theta/2), Cos(theta/2)) Clearly, the above sections are linearly independent and...

I am just wondering, in all of my professor's office, they have a huge collection of textbooks. Did they purchase them or did the university provide the books for them. I am actually thinking of keeping some o mf textbooks and not selling them

Hi guys, Basically I'm working through Jan Smit's book, http://books.google.com/books?id=pFgUFfG7JygC&printsec=frontcover&dq=introduction+to+quantum+fields+on+a+lattice&hl=en&src=bmrr&ei=mabWTOjtMoK4hAfh0eGGBQ&sa=X&oi=book_result&ct=result&resnum=1&ved=0CDIQ6AEwAA#v=onepage&q&f=false , and I'm...

Homework Statement (sorry i have not learned latex to display the maths) Integrating to find the proportion of the area of a sphere that is within the section described by the bounds of theta. theta is longitude axis angle -(pi)/9 <= theta <= pi/9 thi is lattitudal axis angle 0 <= thi <= 2...

In the second degree equation of a conic section (ellipse/hyperbola), I have seen many books following this method to find out the centre of the conic section- 1) Differentiate the equation w.r.t x treating y as constant 2) Differentiate the equation w.r.t y treating x as constant. 3) Solve...

Hey there, I am going to by building a chassis and i am wanting to find out if 33.7mm dia X 4mm thickness circular hollow section or 40mm X 40mm X 2.5mm Square Hollow Section is stronger these two weight around the same per meter thanks Ian

Photon interaction cross section? What?!? Hey guys-- I'm practicing for the GRE, and I came across a question that has stuff that's not even in my textbook! I haven't found much from googling either. Here is the question: My instinct was to guess (C) because graphs I had seen of the...

wikipedia is full of errors

Professor is now teaching us to draw isothermal sections of a Ternary Phase Diagram... Isothermal Section: A “horizontal” section of a ternary phase diagram obtained by cutting through the space diagram at a specified temperature I am so confused... I have big trouble in picturing the...

Homework Statement Suppose there is a Conical section (of a right circular cone) of total height 'l' and radii 'a' and 'b' (a>b). How do we derive the formula for the radius at a height 'h' (h<l) ?Homework Equations The Attempt at a Solution

Homework Statement a) Define the differential cross section \frac{d\sigma}{d\Omega} in “experimental” terms, i.e., in terms of the number of scattered and incident particle. b) Show that for a situation in which there is a scattered wave f^+\left(\theta\right)\frac{e^{ikr}}{r} asymptotically...

design a tension member w/ cross section... Homework Statement You are to design a tension member (square rod) with a cross section to carry a mass of 575 000 kg with a safety factor of 2 against yield and a safety factor of 3 against static fracture (overload). a) What is the design...

Homework Statement Homework Equations know dot product The Attempt at a Solution PART A PART B not sure what's it asking for help would be great

Hi, Has anyone tried using the HFSS software to get the extinction cross section of a particle? I've been told that the extinction cross section of a particle is the imaginary part of the radar cross section in forward direction, so I did exactly what the RCS tutorial from HFSS did, except...

Homework Statement This seems to a reasonably basic question to go through but yet I seem to have a bit of a mental block on it. so any help in the right direction would be great.. An I-beam is 10mm thick on the web and flange, is 6m high and has a Young's modulus of 200 GN/m2. The design must...

I would like to divide the body of my document into two columns. In the left column go the section headings and in the right column go the section text. My attempt is to make a new command: \newdimen\sectionwidth \newdimen\resumewidth \sectionwidth=0.25 \textwidth \resumewidth=0.75...

What's the process that needs to take place to be able to graph the following equation (not-using a graphing calculator): x2 + 12xy + 36y2 + 2x - 3y - 9 = 0 I know to use the B2 - 4AC formula to identify the equation as being parabolic, though I don't understand the formula... Looking at...

I wanted information on the 18F production rates of 18O(p,n)18F compared to 20Ne(d,alpha)18F. I found a 1979 graph that showed some nice curves between 2.3 and 22 MeV but I wanted to see what things looked like between 1 MeV and 2.5 MeV. So I went here...

Homework Statement the prism is made from glass, and its cross section is an equilateral triangle. the indices of refraction for the red and violet light are 1.662 and 1.698, respectively. the angle of incidence for both the red and violet light is 60 degrees. find the angles of refraction at...

Homework Statement I need to calculate the differential cross section in order of Mandelstam variable t, instead of the angle \theta. My problem is with the change of variable not the amplitude of the process. I'm getting a global minus sign which can only be wrong. It seems I'm making a very...

It strikes me that this may well be fairly easy, but i can't quite get my head round the correct way to lay this problem out (at least in a mathematical sense). If you are considering a neutron flux onto a fully understood material, and you also know the neutron interaction cross section of...

I need help with my beam structure in abaqus. The beams I need to model are hollow and elliptical. This is not included in abaqus' library or profiles. So I want to make a Meshed beam cross section as described in the manual. However, the manual is quite difficult to understand. Can someone...

Hi! There is no structural/civil section! Is structural/civil not highly regarded in America? For you civils/structurals: What would you recommend as a good speciality in civil/structural engineering, and why? I'm not looking for the usual listings of specialities, but if anyone has any...

Hey guys I am new here i was wondering if anyone can help me understand this problem better Homework Statement The base of a certain solid is the circle x^2 + y^2 = 9. Cross sections of the solid with planes perpendicular to the y-axis are semicircles with their diameter in the base of the...

Ok. There are 2 universal beams. One is 500mm deep and the other one is 400mm deep. For both beams, the top and bottom flanges are 200mm wide x 10mm deep. [SPAN of the beams is not given] Questions is..If the maximum bending moment capacity of the 400mm deep universal beam is 200 kn.m. What...

What's the relation for the Compton cross section? I remember it going as 1/(1-cos(theta)) but can't remember the rest. I searched for a derivation but can't find one at the moment.

if there is a torque on a channel section twisting it axially what stresses do u expect to be on a side face..??

if there is a torque on a channel section twisting it axially what stresses do u expect to be on the side face ??

Hi This is a long story, I make it short: I am working in a project where I need to find a matrix defined by a third degree polynomial, the solution can be found iteratively using a gradient descent technique, I am using the golden section line search already implemented in MATLAB (with the...

Homework Statement I need to find the values of thickness (t), mean diameter (D) and mean length (L) that will give the minimum area for the streamlined section, given that it's moment of inertia is 5.42 in^4. Homework Equations (the I's and A's after all K's here are meant to be subscripts...

hi We all know when velocity of fluid increases then cross section decreases for same mass flow rate and this can be well seen at water flowing from a height as in waterfalls. But why this doesn't happen when water flows down through a vertical held pipe of constant cross section. Well you may...

Hey folks, i am currently making myself familiar with the path integral in high energy physics by reading Lewis Ryder's QFT book. I do have a question however, since i do not really understand the connection between the path integral and the cross section of a process. Are they only related...

The Wikipedia article Divergence, in the section Application to The Wikipedia article Divergence, in the section [i]Application to Cartesian coordinates, says of the del-dot formula for divergence, "Although expressed in terms of coordinates, the result is invariant under orthogonal...

I am trying to write a program to numerically calculate RCS using geometrical optics (or some form of it). Basically my idea was to cast a bunch of rays from an emitting object (in my code it is a 1 m^2 plate), find where they intersect a surface, reflect the rays off of this surface and see if...

This was pretty cool. I had to draw the cross section of a quad seal (on CAD). It’s basically an O-ring with a cross section that looks like a deformed square with these lobes on the corners. It looks like this: http://www.daemar.com/images/Quad-Ring-PartingLine.jpg But I don’t have...

for the following cross section the ratio Eb/Ep=30 find the shear centre of the cross section ------------------------------------------- first of all i need to find the equivalent cross section, which will be the same except that the horizontal parts will be of length n*L=30*1=30cm...

So, I've been going through Spivak's Calculus, section I, and I'm having some trouble proving 1.1.iii. Also, I'd like to check 1.1.ii and ensure that I did 1.1.i right. So, first, I'm restricted to these nine properties: a+(b+c)=(a+b)+c <P1, addition associative> a+0=0+a=a <P2, additive...

Any comments you have on section 8 of http://arxiv.org/pdf/1005.1057 are welcome and could be helpful. Section 8 "Spin Foams with Matter" begins on page 42 of Marcolli's latest paper. ==quote from ToC== 8. Spin foams with matter: almost-commutative geometries 42 8.1. The noncommutative...