Structure Definition and 1000 Threads

What are the reasons behind the different microstructures of steel at different temperatures? I don't understand why steel at high temperatures (austenite phase) would favor an FCC crystal structure while steel at lower temperature (ferrite) would favor a BCC crystal structure.

My question is that can we use properties of quantum mechanics and thermodynamics to alter size of a non biological object such that properties like its density,optical activity, conductance etc remains same... For instance we know that cooling down a substance considerably reduces its size and...

This i know sounds like a really odd question, but thinking along the Lines that i am.. i guess it has a sense of validity. Could it be Possible, that Planets exist with Dual cores that internally orbit inside a Planet.. or partially joined. Thinking along the lines of Cell structure and how...

Hi. What are superconductor ions? Are they naturally occurring ions inside the lattice structure of a superconductor when it's manufactured or are they ions introduced artificially to a superconductor's lattice ? And do the ions have spin?

What about the structure of glass allows light to pass through, lose 10% of its energy then keep on going when all other object seem to absorb light. what makes clear objects structures so special. When the lights goes through the (regular) glass and loses energy is it losing energy in the form...

Does atom really looks and behaves like as that explained in quantum mechanical model? Or is it just a Mathematical Tool to express the observations? Is it like that that scientist were unable to find any clue about real atomic structure and just created a mathematical tools following the...

I want to write a octave code(It can be another language I want to know how should I think to write a such a code ) to obtain graphene structure like in the figure. This code should give me a graphene sheet which in size I want when I enter the position of the atoms in the lattice.I think that...

I need help to visualize the geometry involved here, How can I visualize the last paragraph? Why is the surface of fixed r now an ellipsoid? Also for r = 0, it is already a disk? I've tried searching for the geometry of these but I can't find any image of the geometry that I can just stare...

Assume the following set of instructions: 1. i = 0 2. if i < n, goto line 6 3. if A [ i ] = = x, goto line 7 4. i++ 5. goto line 2 6. return false 7. return true Assume that line i take Ci time, where Ci is a constant. The worst case total time of running this block of code can be calculated...

Homework Statement Homework Equations N/a The Attempt at a Solution Hi all, For part a) I simply discussed the fact that the contributions to the fine structure arise from the Darwin term, relativistic corrections to the kinetic energy, and the spin-orbital coupling with a bit of detail...

Hi, is there any software that I can use for drawing a crystal structure from atoms coordinates ?

I obtained the black hole solution whose the metric function f(r) and scalar function ##\varphi(r)## are ; ##f(r)=\frac{1}{4}+\left(\frac{Z^{2}}{2r^{2}}\right)^{2}-\frac{1}{3}\Lambda r^{2}## ##\varphi(r)=\pm\left(\frac{1}{\sqrt{2}l}\right)r## where ##Z##, ##\Lambda## and ##l## are just...

I was doing more reading in John Lee's "Introduction to smooth manifolds" and he mentioned that for every n \in \mathbb{N} such that n \neq 4 , the smooth structure that can be imposed on \mathbb{R}^n is unique up to diffeomorphism, but for \mathbb{R}^4 , there are uncountably many smooth...

I saw this antenna matrix on the north coast of California this week on vacation (a couple miles north of Half Moon Bay). It's located about 1/4 mile from the beach on Highway 1. There is a powerline running past it, but it looks to just be getting much of its power from a trickle charge from...

Homework Statement Define a structure VEHICLE which contains producer, model and chassis number. Store the content of a structure in binary search tree such that the key for storing contains all fields of a structure (producer has the highest priority, and chassis number has the lowest). Print...

Are certain DNA (genetic) strands structurally better build for survival than others? If yes, is there a term for this? For example, is there a specific order of nucleotides that is harder to destroy than another? Or if there is a specific order/combination of nucleotides that would have...

Hi, I've been working on a problem for some time now and I can't figure out why exactly this happens, and I've been looking for some insight. The phenomenon can be seen in this video. We can see that the oil rearranges itself due to a high-voltage electric field. Thinking about this, my...

hi guys i've really been struggling with this question but I still can't get any glimpse of idea on how to solve the problem, so the conditions are given in the table and what the question is asking for is the axial force acting in each members of the structure. ah, almost forgot to tell you...

Hello, I'm Harry. I'm new here, hope not breaking any posting rules in any ways :) I have a question and would like to ask for some suggestions and information. The question is about general relativity or gravity and structure of the Universe in general; I know there are definitely quite a...

I am wondering if there is any consensus on the structure terminology of the brain. 1 - I've heard that the brain has the reptilian, mammalian(limbic) and neocortex parts that overall perform specific functions and evolved in that order. - On that note, would reptiles have had any really...

So I have to do this question and I attempted this. Can anyone go over this and see if I did it correctly. Another student from my class told me I had to use the torque in order to calculate Fab but I don't see how I would do that.

Homework Statement Book says "Substances with a simple molecular structure do not conduct electricity. This is because they do not have any free electrons or an overall electric charge". Homework EquationsThe Attempt at a Solution I think the statement is a generalization because water is a...

I often encounter situations in my professional development like if ( condition1 ) { // do this } if ( condition2 ) { // do that } if ( !condition1 && !condition2 ) { // do something else } and I handle it in exactly that manner. (Note: this is not an if-elseif-else situation...

I want to do an experiment where I follow the particle in all trajectory until it hits the wall of the box, then I want to draw out this box's structure based on the particle collision. One thing would be that the particle does not need to go in all trajectory, but I would like to know how to...

Consider the Dirac equation for bounded electron in hydrogen atom. I am trying to get a clear physical explanation for all mathematical terms that appear in the Hamiltonian and energy spectrum. Kinetic and Coulombic potential and rest energies are the first terms and easy to identify. Then we...

I'm teaching myself how to do DFT for my master's project, where I want to use it for calculating band structures for different heterostructures. Now to learn DFT I am on one hand reading a book on the basic theory, on the other hand using different freeware packages to try and calculate the...

I know how to calculate band structure of two dimensionaI sheets by tight binding. I am looking for a reference to learn thoroughly how to calculate band structure of 2d-ribbons (Graphene nanoribbon, Silicene nanoribbon,...) using tight binding method. Could anyone please help me?

The commutation relations for the ##\mathfrak{so(n)}## Lie algebra is:##([A_{ij},A_{mn}])_{st} = -i(A_{j[m}\delta_{n]i}-A_{i[m}\delta_{n]j})_{st}##.where the generators ##(A_{ab})_{st}## of the ##\mathfrak{so(n)}## Lie algebra are given by:##(A_{ab})_{st} =...

I have some qualitative questions about the relation between band structure, density of states, and Fermi energy (or Fermi level). 1) Say you have a given electronic band structure (energy as a function of k) obtained by any method. How do you relate this to the Fermi energy (or Fermi level) ...

I almost "get" it, but not quite. Can someone help? Here is my current understanding. Say you solve the Kronig-Penny model. You find that you get bands of N closely spaced energy levels, with large gaps between them. Under normal conditions, electrons fill the band to some level (let's say we...

Homework Statement Let (S,\cdot ) be an algebraic structure where the operation \cdot is associative and commutative and also the following axiom is satisfied: \forall x,y\in S,\exists z\in S: zx = y\ \ (1) Prove that if for every a,b,c\in S, ac = bc, then a=b. Homework EquationsThe Attempt...

I've been reading about the Dirac equation, and most authors eventually make some statement to the effect that the fact of spin and antiparticles falling out of the equation reflects a deep connection to the structure of spacetime. Is the implication that the math requires four particle states...

The structure factor in solid state physics (https://en.wikipedia.org/wiki/Structure_factor) apparently gives information on the scattered ray from a lattice. How exactly does it do that? Does a structure factor of zero at certain points imply that rays cannot be scattered in those...

Hello! I've been trying to figure out what the most stable structure of inositol is, but I keep running into conflicting information. I'm not sure whether the most stable conformation is the myo-inositol form or the scyllo-inositol. All of the stereoisomers can be seen on wikipedia at this link...

I have done my research and understand why quantum tunneling happens and I fully understand that there is no point at which the particle examined ever actually intersects with the barrier. The only part at which my knowledge feels fuzzy is at the mathematic equations. If a large object, such as...

Homework Statement If we take the average radius of the electron wave function in the ground state of hydrogen to be the Bohr radius, calculate the average potential energy of the electron due to the Coulomb interaction with the nucleus. State answer in eV. Homework Equations I think the...

Do any band structure (in absence of any external field) in general, is symmetric with respect to k? In other words, do we always have E(k)=E(-k).

Does "quasi-two-dimensional structure" of cuperates mean that a cuperate material is regarded as a stack of thin layers and there is almost no structural interaction among the layers? BTW, is Meissner effect meaningfual to a thin film superconducting material? Thank you.

Is the claim that all definitions are biconditionals, true? Is the converse statement true as well, that all biconditionals are defintions?

Take a prime order cyclic group. I want to take that as the additive group of a finite field. Since every finite field of the same order is isomorphic to one another, does the isomorphism define a multiplicative group structure on my cyclic group elements?

Hi I have a few questions that I have been working on but I don't get the right answer. After drawing the Lewis dot structure of HOClO2, pick the incorrect statement of the following. A. The oxygen bonded to the hydrogen has two lone pairs B. the oxygens not bonded to hydrogen have three lone...

Hi All A mathematical structure : is A set with an Object ( structure ) and there are generally two types of mathematical structure , which are algebraic structure and space ( geometric structure ) Eaxmples of algebraic structure are rings , fields , modules vector spaces ... act Examples of...

Homework Statement I have the following code which manipulates with basics of structures. There are function like reading and sorting data from structures. Now, I don't know how to write a function that reads name and surname of an author of a book, and then prints data about books that are...

Trying to reverse-calculate an equation to achieve one of the original variables when not present. 1) You have a number... A (which is always a positive number) 2) A is multiplied by 1.75% 3) This result is then added to A, and the resulting sum being B, i.e. (A x 0.0175) + A = B In my...

I just saw the following news and thought this could have quite an impact on our current models and views of the Universe: The GRBs that make up the newly discovered ring were observed using a variety of space- and ground-based observatories (the sample is listed in the Gamma Ray Burst Online...

I am in the final stages of the project I've been working on: Taking a Dynkin diagram and deriving the structure factors for the Lie algebra it represents. Yay me! However. I am confident in my work but it would still be really nice to be able to check them. Does anyone know where to find a...

Simpel question: does an atom consists of matter and charge? Yes/no?? If no Then what?

Homework Statement Calculate the surface density (planar density) of the Silicon diamond structure in the [1 0 0],[1 1 0],[1 1 1] planes. Given a = 5.431 A (latice constant) Hint: For the (111) plane, it should help you to think of the diamond lattice as two interpenetrating FCC lattices.2...

Hello. I use a MC12079 as UHF divider by 256. Unfortunately this IC was oscillating at about 10 MHz. To correct this problem I insert a 47 k resistor between non inverting input and Gnd as Inverting input is used for signal to divide. It works, but I would like to know if this can have unwanted...

Dear forum people I consider four atomic orbitals of the silicon atom: s, px , py and pz , thus Hi,j is a 4*4 matrix. Hi,i is the expression of the diagonal matrix and Hi,j is the expression off-diagonal matrix where the expression for Hi,i and Hi,j is attached. But I can not calculate the...