Structure Definition and 1000 Threads

Hi, all, I want to calculate the band structure and there is example such like that: BandLinesScale pi/a %block BandLines # These are comments 1 0.000 0.000 0.000 \Gamma # Begin at Gamma 50 2.000 0.000 0.000 X # 25 points from Gamma to X 20 2.000...

Since pure dark matter apparently does not have charge but has mass, might it be found in the galaxy's edge as something akin to uncharged black holes? Typically, pure dark matter is invoked as particles. Wouldn't they form aggregations under gravity? Extended (i.e., not particulate) dark...

I am in intro to genetics class and I am getting really confused with the terminology: -Is a chromosome made up of 2 sister chromatids? -are the 2 sister chromatids identiical? -what's the difference between chromatins and chromatids? and between the kinetochore and centromere? -gene...

I plan on building shelving using 3/4" pipe and fittings. The general design is a 2 shelf system -180 degrees from each other around a center pole at different heights. I plan on bolting the center pole to a plywood base. Each shelf will hold between 5 and 100 lbs. I want to make sure its...

I was just wondering what the physical interpretation is of 'fine structure effects'? (where alpha is the fine structure constant).

How is fascicle arrangement linked to muscle structure? Does anyone know where I can get videos on fascicles? Thanks

In short, if we consider the group of symmetries of a regular octahedron, we see (or at least, the author of "Groups, Graphs and Trees" saw...) that the group is isomoprhic to Z2\otimesZ2\otimesZ2\otimesS3 - particularly since if we break up the vertices into 3 groups of front-back, top-bottom...

What is the difference between levels of protein structure ( Primary , Secondary , Motifis , Tertiary , Domain and Quaternary )

Problem For Structure of Nuclei -- Enigmatic ! Question :- calculate the distance of closest apprach for a head on collision between 5.30Mev alpha particle and nucleus of a copper atom? Answer The distance of closest approach is given by...

Hi, just a basic question , what are the main methods of determining the structure of a solid in order to test its genuinety i.e. gold... if i were to be given a piece of gold, how would i check that it is genuine gold? could i use x ray diffraction (If so what measurements /tests would i...

Homework Statement The problem is this. We have a structure (see the attached image) and need to make freebodies of all of the members. 150 lbs are applied to the platform being lowered by the strings. We also need to figure internal stresses, but I think I can get those if I can understand...

Could someone explain the relationship between the FSC and the Planck Scale? What are they in relation to each other. I know what the Planck Scale is, and I even have a loose understanding of the FSC, but what of them in contrast and comparison? And how does the FSC affect QM, if at all...

Hi everyone! I wanted to ask if in your opinion is it right to say that band structure calculations (and hartree fock calculations) could live in a framework of the fermi liquid theory where quasiparticles are one-electron states (which could be or not could be the case)...

I don’t understand what our teacher means by this: " Analyze the correctness (or lack of it) of a common approximation made in structural design, which is that the weight of the structure can often be neglected when calculating the loads carried by the members in the structure."

a question in Lewis structure? I know that Lewis structure is so easy to discuss ..but I have this compound : SnCl2 when I drew the Lewis structure of its , I had to make Double bond between the Cl & Sn ..but a teacher told me once that when the Cl is not the central atom it can just make...

i study from some books that the properties of a materials depends on the structure of it, while the structure depends on how it being process..may i know what structure actually it means? i can't get its meaning..does it means the processing methods will influnce whether the materials will be...

Homework Statement Please tell me about NMOS and PMOS, What are their Structure and Application Homework Equations The Attempt at a Solution

hey, how can ı show the reflections over the line do not have group structure? --reflection of the real plane ------

1. Homework Statement Using the powder XRD data below, show that the substance has a face centred cubic structure. (xray lamda = 0.154056 nm) Peak No.------2(theta) 1 -------------38.06 2 -------------44.24 3 -------------64.34 4 -------------68.77 5 -------------73.07 2...

Homework Statement Using the powder XRD data below, show that the substance has a face centred cubic structure. (xray lamda = 0.154056 nm) Peak No.------2(theta) 1 -------------38.06 2 -------------44.24 3 -------------64.34 4 -------------68.77 5 -------------73.07 Homework...

I was asked to draw the resonance structure of nitrous oxide and given some bond length. So i need to eliminate non-probable resonance structure for nitrous oxide. I was able to draw three structure but how do we use the bond length to liminate non-probable resonance structure for nitrous oxide?

Alright. Um. We have 4 sheets of newspaper and 1 meter of masking tape. We have to design a structure to catch four eggs dropped one after another from a point at a height of 6 ft. What do you guys think? We've tried making just a simple 'basket' filled with crumpled paper and it doesn't...

Would the structure of Dinitroacetylene be... NO2-C(triple bond)C-NO2? If the triple bond makes it prone to exploding then woud something like NO2-O-C(triple bond)C-O-NO2 be even more explosive?

Homework Statement It commonly happens that the hyperfine structure in a transition is dominated by the contribution of an s-electron in one of the levels. What property of s-electrons could be responsible for this? A transition of this kind occurs at 494nm in singly ionised 133Cs between a...

Modal realism! 1. All mathematical structure exist necessarily. 2. Our universe/multiverse is a mathematical structure. ------------------------------------------------------- A) Our universe/multiverse exist necessarily. Consciousness 1'. All mathematical structure exist...

Hi all, I was struggling in solving this question which is a part of a practice exam, and I need you to be patient with me and teach me step by step how to figure out the structure and how to read and analyze the spectra. I attached the two 1H NMR & IR spectra so you will be able to know...

Ok as the title suggests I want to clear up my misunderstandings on protein structure. 1. When they say primary,secondary,tertiary and quarternary structure do they mean different stages of a protein. What I mean is do all proteins have a tertiary or quarternary structure and are...

I'm interested in calculating (followed by optimizing) the uniformity of a magnetic field generated by an array of neodymium magnets. Let us assume we have an array of neodymium bar magnets, -each with a constant depth (10mm) and height (2300mm). -Multiple segments (with alternating poles)...

I was reading Hodges' Model Theory when I came across this question in the first chapter: Specify a structure of cardinality w2 which has a substructure of cardinality w but no substructure of cardinality w1. (Working in ZFC) I am assuming w2 means 2w1 but I'm not sure. I haven't really...

There is a space station of the length L and uniformly distributed mass M on the low Earth orbit. One side of it always faces the Sun. Which tension will the structure experience? My attempt of the solution: bottom of the station is L/2 meters below the stable orbit at that velocity...

Just wondering about the "structure" of a determinant... How much can a determinant tell you about the entries of a matrix? How much more if you know the size of the aforementioned matrix? How much more if you know that the matrix is symmetric?(perhaps a silly question). How much more if you...

Dont have to be mean?

Lewis structure (Related! - Please Help!) I have 2 problems, please help me!please! thank you so much! Homework Statement Can you tell me if I am correct?Thank you so much!I tried acd and ac but it's wrong! :( 1. Which of the following are true about the correct Lewis structure of the SeF2...

Many interesting proofs in GR (regarding black holes and singularities, etc.) involve topological methods. However, I don't understand how a theory embodied in Einstein's equations, which appear to me to be local rules of evolution, can ever change the topology since a patch of spacetime...

I understand that the formal structure of QFT has resisted axiomatization (so far) and that what formal structure presently exists is really a set of recipes. Can somebody outline the recipe please.

Homework Statement dB = 12mm (0.012m), dC = 20mm (0.02m), E = 140GPa and the coefficient of thermal expansion, α = 12e-6/°C. Homework Equations δ = (R*L)/(E*A) The Attempt at a Solution Please see picture for my attempt. I don't know how the thermal expansion, which...

Hi all. I am a PhD student in a condensed matter group. Consider: I observe superlattice reflections due to ferrimagnetic order that requires one cell parameter to be multiplied by M, the next by N and the third by O . In other words, the magnetic order is described by a magnetic unit...

Quark physics is completely out of my depths but I was wondering if, in a nucleon, they assume certain orbitals like s,p,d,f, ... Does one quark tend toward the center? Is there a valence quark? Do any symmetries form?

http://img233.imageshack.us/img233/5816/espaotempoquntico1.th.jpg Two pictures of quantum spacetimes... The theory of quantum gravity (LQG) can perform calculations and predictions on the concrete structure of space and time at the Planck scale. Equations formulas that describe...

Homework Statement CH3CH=CHCH3 What's the cis and trans structure name for this formula? Homework Equations The Attempt at a Solution I've drew the ciis and trans structure H\ /H C = C / \ CH3 CH3 this is the cis the tran is similar to...

HI, A chemical has a name of Bis(2-ethylhexyl) 1,6-hexan-1,6-diylbiscarbamate, I wonder which structure is correct (sorry it seems like I can only paste smile strings, You can see the structures by depicting them on http://www.daylight.com/daycgi_tutorials/depict.cgi)...

Homework Statement write lewis structure for SOCl2. Homework Equations The Attempt at a Solution .. .. .. :Cl-S-Cl: .. | .. :O: .. what i did was put S in the middle with a single bond on both side for Cl, each Cl has six dot. S has two at the top. I...

Hi, Could someone tell me please what is the scientific consensus(or some interesting theories) on why do muons decay and what is the mechanism of it? My understanding of particle decay is based on for example neutron wchich decays because a quark in it flips from down to up. But leptons, if...

Hey guys I've got a question and I am not sure how to go about answering it without looking up a table of characteristics of elements! Niobium has an atomic radius of 0.1430nm and a density of 8.57g/cm^3. Determine wheather it has an FCC or BCC crystal structure? Now i think you have to...

Hi, I am searching for a structure that would take a load (150kg). The problem is that I want it not to break (Sigma=P/A) but I want it not to be stiff (K=AE/L). The only parameter I have is the area A but it is opposite in the equations (I can't really change the length and I did not...

Is there a data structure like the union-find data structure, but for intersections (and the sets needn't be disjoint)? I'm looking for a data structure that stores an indexed set of sets A_1, A_2, ..., A_n, and supports the following operations: replace the sets A_i, A_j with their...

Hello! I have noticed that most advanced textbooks on QM start the development of the subject with a long review of linear algebra. In particular, they talk about pre-Banach, Banach, pre-Hilbert, Hilbert spaces and so on. Why is it necessary to invoke such abstract spaces in order to describe...

so with buoyancy and liquid pressure i am pretty sure i know the answer but i just want to confirm (please don't laugh if it's obvious) - upwards buoyancy pressure only acts on the surface of a structure that is faced down - the bottom of the structure that supports all the mass of the...

In another thread Fredrik referenced THE RICH STRUCTURE OF MINKOWSKI SPACE at http://arxiv.org/abs/0802.4345..(The math is NOT simple!) But the introduction got me wondering... around page three is this statement: So what knowledge regarding more exact models of spacetime and the relativity...

In special relativity the clock hands velocity is represented by: V = v0*(1-v2/c2)^1/2 then: What happen with electrons angular velocity in atomic structure? It may be the same?: V = v0*(1-v2/c2)^1/2 if this could be true what happen with matter?