Properties Definition and 1000 Threads

Does anyone know of a class or a textbook or anywhere to start doing research on how to start off with a set of desired properties of a material and begin designing that material from a molecular level. A for instance would be say you want a material that is capable to separating oxygen from...

Hi, I need help with some basic Fourier transform properties stuff - its fairly simple though I think I am doing something wrong. So we know from the shifting property if h(x) has the Fourier transform H(f) then h(x-a) has the Fourier transform H(f)ei*2*π*f*a so I have the function cos(2πf0x...

Homework Statement Prove the following property: If m <= f(x,y) <= M \hspace{2 mm} \forall (x,y) \in D, then: mA(D) <= \int\int f(x,y)\,dA <= MA(D) Homework Equations I use a few other known properties in the proof (see below) The Attempt at a Solution First, I should state that this problem...

Hey Folks, I wanted to put together a single spreadsheet of subatomic particles (e-, ν, b, t, π Ξ, Σ, Δ, etc.) and their properties that have been measured (mass, mean lifetime, valence quark content, charge, spin, parity, etc.). I have been looking through the PDG website for some way to...

Homework Statement This problem is very easy, but I'm not sure how best to "prove" it. This part of the question just states: Prove that (1/z)* = 1/(z*) where z* is the complex conjugate of z. Homework Equations The Attempt at a Solution So the complex conjugate of z = x + iy is defined is...

It is often stated and proved in textbooks that the momentum density is also the energy flux. The explanation is often done using the dust model. However, it is possible that in a real fluid, there is heat conduction via particle collision. There is energy flux, but since no molecules are ever...

Homework Statement Let ##f,g## be non-negative Lebesgue measurable functions, and let ##E## be a measurable set. Prove that: ##f\ge g\implies \int_E f d\lambda \le \int_E g d\lambda## Homework EquationsThe Attempt at a Solution I've been trying to apply Fatou's lemma but haven't been getting...

Homework Statement Determine which of the formulas hold for all invertible nhttp://msr02.math.mcgill.ca/webwork2_files/jsMath/fonts/cmsy10/alpha/144/char02.png n matrices A andB A. 7A is invertible B. ABA^−1=B C. A+B is invertible D. (A+B)2=A2+B2+2AB E. (A+A^−1)^8=A8+A−8 F...

Dear all, In one of his lectures,Prof. Susskind mentioned that the event horizon "bulges" forward to meet any incoming radiation or matter; and it is a property of Einstein field equations. I have not come across any such property, and if it exists, shouldn't it belong to the Schwarzschild(or...

Hey everybody; There is something I don't understand. I need to find the properties(E,Poisson's ratio, G) of e-glass fiber 420 gm bi-bias. I find some interesting websites but each time when they give properties, they don't give the basis weight. So if I understand, mechanical properties are...

Hi, let ##h: A \rightarrow A ##be a homomorphism between algebraic structures. Is there a nice result describing the properties of ##Ker h^2 ## , where ##h^2 = hoh ## (composition) ? Clearly , ## ker( h) \subset ker (h^2 )## , but are there some other results relating the two; maybe relating...

Homework Statement from -lnIxI to lnI x^-1I , I try to go from -lnIxI to lnI x^-1I by using some properties. Homework Equations - lnIxI The Attempt at a Solution First I write the -lnIxI as -1*lnIxI and then I use -1 as an exponent to absolute value of x in the natural log that is ln (...

Hi I need help regarding following can I write following partial derivative wrt x multiplied by Ax (∂A[x])Ax =∂(Ax^2)

Hi there I need to know the density, viscosity, heat capacity,and temperature for the oil or crud oil? Also I need to know the wall temperature for pipe? Can anyone help me please ?

How can you tell NH3 is a better base than HOCOO-? I look at the conjugate species in both to determine their relative stabilities. Where NH4+ is the conjugate acid of ammonia and HOCOOH the conjugate acid for acetate. In this case, isn't the NH3 more stable than NH4+ since it is uncharged yet...

When looking at the cage or structure used to carry materials into an oven for the annealing process, what material properties are most important? Lets saying during full annealing of aluminum, the oven is heated to 540 degrees Celsius. A cage is used to carry the aluminum into the oven...

x + 0 = x x - 0 = x x(0) = 0 x(0) = undefined ...is this how you call it or is it no solution? x^0 = ? What is x raised to the zero power? square root of 0 = ? Not sure about this one either. If anyone knows of any other properties of zero I'm leaving out, please feel free to...

If there is a graph that has a discontinuity (e.g. at x = 3) and then the there is a point much lower than the limit at 3, is that point at 3 considered a local minimum? Also, if the graph starts w/ a discontinuity at its "highest point", does it have an absolute maximum?

Due to the blogs being removed, I thought it might be worthwhile posting a few in the forums- From 'Exploring Black Holes' by John Wheeler and Edwin Taylor; can apply to any object falling radially towards a static spherical mass (where the mass of the infalling object is much smaller than...

I beg forgiveness if this should be in chemistry; to me it seems more of a physics problem. This summer I had two Polyethylene terephthalate (PETE) spice bottles deform due to the sun shining on the clear plastic tub, Polypropylene(PP) in which they were stored. The first time the big tub was...

Hello , firs of all I know that every magnet has two poles ad the field lines exit one pole and enter into the other , now if we take a bunch of magnets , for simplicity assume an infinitely long line of magnets each separated by a distance , all of the magnets facing N-S N-S N-S , now do the...

Hi, I'd like to know the log properties when they are the power of a constant. I've searched everywhere but I can't find it. the reason I want to know it is that, when solving a recursion tree problem, my teacher got an result of n^(log4 3) but I got 3^(log4 n). the base of the log haven't...

My prof was going over some definitions and he made a statement about ratios of extensive properties, he said: $$\frac{Extensive}{Extensive}=Intensive$$ But could someone confirm for me that this is only true if I'm doing this with the same extensive property. In other words, as a...

Homework Statement This question being for my physics summer work states "List three properties that all numerical answers must have to be correct" Homework Equations None The Attempt at a Solution 1. must be a numerical value? 2. must show accuracy. 3. must show precision.

Mylar is an insulator, but it is coated with metal. Intuitively it should be possible to wrap a laptop in mylar and insulate the laptop from radio signals... but is there any chance it might affect magnetically the computer and/or its hard drive? I mean a very loose airy wrapping, like in...

Hey guys I'm new here and I've been using MathType for all on-screen math. For some reason PF doesn't recognize the built-in Dirac's bra-ket notation. (i.e. <\psi|) So I've included my equations and solution in the format of images, hopefully it isn't a problem. Homework Statement Proof...

Definition/Summary A Lune is a diangle on the surface of a sphere whose two vertices are opposite points. So the two angles of a Lune are equal, and each of the two sides is half a circumference. The whole surface is a Lune of angle 2\pi. Equations Area of a Lune: 2 r^2 \theta...

What is difference between iron that we use in food...and iron metal

Homework Statement progressive waves are only for transverse waves ? or it can be also for longitidunal waves? Homework Equations The Attempt at a Solution

Homework Statement Delta functions said to live under the integral signs, and two expressions (##D_1(x)## and ##D_2(x)##) involving delta functions are said to be equal if: ##\int _{ -\infty }^{ \infty }{ f(x)D_{ 1 }(x)dx } =\int _{ -\infty }^{ \infty }{ f(x)D_{ 2 }(x)dx }## (a)...

Hi everyone, I need some specific mechanical properties of A516 carbon steel, but as yet I am unable to find it online. Can you help me find the fatigue limit and the relation between yield strength and temperature? Are there tabulated values for this? Thanks! Mark edit: found it! seems i...

Hi - I am currently working on a paper verifying some thermal hydraulic code against experimental test data for subcooled water subchannel flow. I have close to 1000 points in excel all listed with T & P and the process for inputting the corresponding enthalpies for subcooled water by lookup...

Hi. This is something I've been wondering about. If one looks at a phase chart like this: http://en.wikipedia.org/wiki/Phase_diagram#mediaviewer/File:Phase_diagram_of_water.svg you notice something. First off, as the pressure is reduced, the liquid range shrinks and then disappears at...

Hello :) I am Jon and I am conducting an experiment with Quartz Crystals to test their piezoelectric properties. I wanted to ask you a question about my experiment set up. Which type of force is required to be applied for voltage to be produced? Could I apply a compressive force with...

Homework Statement My textbook says any integer greater than 1 is a product of primes. Wouldn't that mean that there are no prime numbers? What is the product of primes that create the integer 23? Homework Equations The Attempt at a Solution

what is the properties of chimcal reaction for carbon and sulfur in gunpowder...and what different reaction happens if the gunpowder have just carbon without sulfur

I have just finished a post on the Linear and Abstract Algebra Forum on Universal Properties, I am having trouble with the following line of Latex: [a_1]_\sim_R , [a_3]_\sim_R , [a_5]_\sim_R , [a_7]_\sim_R, [a_8]_\sim_R The effect that I wanted for each quotient was as follows: Can...

I am reading Paolo Aluffi's book, Algebra: Chapter 0. I am, at present, focused on Chapter 1, Section 5: Universal Properties. I subsection 5.3 on Quotients, Aluffi writes the following: I am uncertain of the nature of the category that Aluffi is constructing. in particular, do the functions...

Why should we bother about Extensive properties in Thermodynamic systems? and Why do we need specific value of some thermodynamic property? and what does it tell us about the system? Eg. specific heat capacity? How density of a thermodynamic system is a intensive property?

This is one of my weakness in Math, to prove an existing fact. please Tell how to go about doing these problem. 1. Prove that when the discriminant of a quadratic equation with real coefficients is negative, the equation has two imaginary solutions. 2. Prove that when the discriminant of a...

Hi I am a HNC student an am having trouble with this question below... A universal I section beam is simply supported at each end and must withstand concentrated shear force of 240kN vertically downwards. if the maximum allowable shear stress in the beam is to be 65MkN/m^2 determine the...

Hi, I am a Bachelor Student of biomedical engineering and I have a question regarding the complex compressive modulus. I am really a newbie in this field, hopefully somebody can help me. I have measured four different hydrogel films to compare with the same conditions using a dynamic...

12a) Sketch the sinusoidal graphs that satisfy the properties below: Period: 4 Amplitude: 3 Equation of the Axis: y = 5 Number of Cycles: 2 So, I know how to graph sinusoidal functions, but I can't figure out the max and min that would satisfy both the equation of the axis and the amplitude listed.

I was wondering is there is a simple way to show electron's wave properties, by using the double slit experiment as a reference. What I think I need: White Board that's reactive of electrons Something with 2 slits Something that can shoot out electrons For something that can shoot out...

I was watching Fay Dowker's "Spacetime and the quantum: united by history" on Youtube, and a question occurred to me. She has the unique ability to combine enough detail with a popularized version to accurately portray some of the big, current issues facing physics. The question is...

I have recently been learning about the microscope properties which dictates electrical resistance. The main equation (resistivity) in my textbook is: \rho = 2m/qN\tau where \tau is the time between collisions of electrons with the atoms, q is the charge of the electron, N is the number of...

If there are real photons it might be considered reasonable to assume that each photon has certain properties. Here I am interested in finding out all known photon properties, initially by means of making a list. I have started a list and would appreciate if any additions are made to it. I would...

hello everyone.. 1) what is the magnetic properties for indium oxide? i hope that it has ferrimagnetic properties (ferrite) so that i can mixed it with ferroelectric material, to form a multiferroic materials. 2) i have planned to use barium titanate as my ferroelectric material in my...

It is well known that a vector can't be divided by a vector, as a direction can't be divided by a direction. Keeping this in mind, I used the equation, v→ = u→+a→t, and wrote it as t = v→ -u→/a→. Now, isn't it wrong to write the equation like this? As , in it, a vector, that is v→ -u→ is being...

Homework Statement ''A rigid insulated container fitted with a paddle wheel contains 5lb of water, initially at 260F and a quality of 60%. The water is stirred until the temperature is 350F. For the water, determine the work.'' How do we know whether the state of the water at 350F is...