Structure Definition and 1000 Threads

My question is if fibrous proteins posess secandory or if they posess tertiary structure There is a fiery debate between me and one smart dude from my class.I believe(firmly) that proteins posess secandory structure while he is of that school of thought that believes fibrous proteins have a...

Silicon Band Structure for both ibrav 0 and ibrav 2 I did scf and bands for silicon using both ibrav=0 and ibrav 2 After running the two bands separately I noticed that the band structures for the two (ibrav 0 and ibrav 2) were totally difference but in literature i read that the two (both ibrav...

Hi, Let ##M^3## be a 3-manifold embedded in ##\mathbb R^3## and consider a 2-plane field ( i.e. a Contact Structure) assigned at each tangent space ##T_p##. I am trying to understand obstructions to defining the plane field as a 1-form ( Whose kernel is the plane field/ Contact Structure) Given...

A group of scientists have assembled transmission electron microscopic (EM) images from the serially sectioned brain of a female fruit fly (Drosophila melangaster, a model research organism) to make a database of the detailed structure of its brain. Z. Zheng et al., “A complete electron...

Special relativity says that all clocks will show same time dilation, irrespective of clock mechanism. But Time period of a clock is a formula that must continue to hold even if time dilates. Let us look at a tuning fork clock. Here time period depends on the dimensions of the vibrating...

This of course is speculative, but IF faster-than-light travel (or wormhole tunneling or some other exotic means) was found to be able to communicate information from the future to the present, what would that indicate about the structure of time? Some might argue that indicates a block-type of...

On the topic of structural tubing... It is my understanding that round tubing is stronger than square tubing, or conversely that, that round tubing is lighter for a tube of the same strength. Does it necessarily follow that the best possible use of material when making a tube, is to use it all...

Homework Statement The energy-band dispersion for a 3D crystal is given by $$E(\mathbf k) = E_0 - Acos(k_xa) - Bcos(k_yb) - Ccos(k_zc)$$ What is the value of the effective mass tensor at ## \mathbf k = 0 ##? Homework Equations The effective mass tensor is given by $$ \left( \frac{1}{m^*}...

If caesium 133 frequency for its hyperfine structure is 9 192 631 770, and hydrogen is 1 420 405 751.7667 what are the frequencies for the other elements and their isotopes? Is there a list on line some were because this would be a long list. Any help on where to look on line would be...

Hello! I would love to get help on this particular question that I find extremely difficult to answer. -"Bariumtitanate can under a certain set of conditions crystallize in the given structure. With the help of the compounds symmetries, explain how it is possible for it to achieve such a...

Both the gravitational and electric fields associated with matter are centered on the matter itself. However, for a bar magnet, the magnetic field seems to be emanate from discrete loops, only part of which pass through the matter of the magnet. What causes a magnetic field to have this...

This is the AN/APG-81 AESA Radar antenna by Northrop Grumman currently found in the F-35 (photo from wikipedia article). It seems to have a very different structure than past AESA/PESA antennas. For example the APG-68 from the F-16 looks a lot like stacked, slotted wave guides to me. So...

Hi. I am trying to understand the images that I have posted below. Each layer of Mathematical Structure Hierarchy in the image in this post and Mathematical Space Hierarchy in the image in this post are: statements. 1. What do these statements of each layer of these hierarchies in the...

Homework Statement In a gas of hydrogen under normal conditions, the interatomic spacing is 1.56 × 10^−8 m . Assume the gas is made of atomic, not molecular, hydrogen. For what n-value of the hydrogen atoms is the size of the atom comparable to the interatomic spacing?The value of h bar is...

Homework Statement Consider the NaCl molecule, in which the atomic weights of Na and Cl are 23 and 37, respectively. The internuclear separation is 0.236 nm, and the ”spring constant” for vibrations is k = Mred ω^2 = 1 × 10^9 J/m^2 . Calculate the energy difference between adjacent vibrational...

Homework Statement I've been trying to find the unknown forces for this beam so I can complete an FEA analysis. Homework Equations ∑mz=0, ∑fx=0,∑fy=0 The Attempt at a Solution Attempt is attached

Proposition: Consider an ##n + 1##-dimensional metric with the following product structure: $$ g=\underbrace{g_{rr}(t,r)\mathrm{d}r^2+2g_{rt}(t,r)\mathrm{d}t\mathrm{d}r+g_{tt}(t,r)\mathrm{d}t^2}_{:=^2g}+\underbrace{h_{AB}(t,r,x^A)\mathrm{d}x^A\mathrm{d}x^B}_{:=h} $$ where ##h## is a Riemannian...

Griffith's Introduction to Elementary Particles, if I understand it correctly, states that in QED, the fine structure constant contributes less and less to the strength of the EM interaction as we add more and more vertices since the constant is so small (1/137). However, in QCD, since the...

Homework Statement Draw the Lewis structure and structural formula for: a) HCN b) SO3 2- Homework Equations none The Attempt at a Solution Did I do these correctly? Thanks!

Homework Statement a) Calculate the differences in electronegativity between the elements in each of these compounds. I)CaBr2 II) Na3N III) CH4 b) Predict whether each of these compounds would be an ionic or a molecular compound and justify each prediction. c) Rank the bonds in these compounds...

Homework Statement I am asked to discuss the band structure of diamond. I saw the band structure of diamond has 4 filled valence bands and then 4 conduction bands. Silicon, the same. Homework Equations --- The Attempt at a Solution I'm feeling really silly because I don't understand why it is...

Hi, I forgot a water-filled balloon in my backyard last fall. When my kid brought the frozen balloon in and removed the rubber, we were surprised to see the beautiful structure inside the ball of glass. I remember that glass paperweights used to have similar designs inside them. I used to think...

Would it be possible to build a small 20' X 20' or 30' X 30' building using car tires using maybe one layer tires then black plastic to keep rain out then another layer of tires? If you just stack them vertical for the wall how would you build roof? Stacking them like great pyramids would look...

I came across this pie-in-the-sea concept: (Obviously, the pictured structure would be extremely susceptible to complete catastrophic failure, having no apparent internal means of water-tight seals to prevent complete implosion. Which is why you'd more logically build a city in tube-and pod...

Regarding the recent discovery by Ken Ono and colleagues of the fractal structure of partition numbers for primes: a great lever of intuition would be to see a diagram, or any presentation of the numbers that reveals this fractal structure. Perhaps the fractal structure is somehow hidden in a...

see this diagram of the structure of diamond given in my textbook- I have read in my textbook that each carbon atom in a Diamond crystal is attached to four other carbon atoms by strong covalent bonds.But, in the diagram above I can see that some of the carbon atoms are not attached to 4...

Homework Statement All data are in the image uploaded Homework Equations I don't know how to deal with two confounded loads The Attempt at a Solution I really need fast replies thnak for your attempt

Background The chart above, via Lubos Motl's blog which is standard in any textbook talking about supersymmetry, illustrates the running of the the inverse of the Standard Model (SM) and Minimal Supersymmetric Model (MSSM) coupling constants with energy scale for the electromagnetic force...

I understand that pH affect the tertiary structure as it will change the ionic interactions between the COO- and NH3+ groups, however, as the secondary structure is caused by hydrogen bonds, how does pH affect it? Is it because the change in tertiary structure will alter the shape of the protein...

if n is a positive integer greater than 2 and m the smallest integer greater than or = n, that is a perfect square. Let a = m-n. Show that if n is prime, then a is not a perfect square. Also, is the converse of above true, for any integer n? any guidance, will be much appreciated? Thanks

α decay probably implies that heavy enough nuclei which undergo this decay, consist relatively loosely bound α particles and extra neutrons. I haven't found any theory which views nuclei in this way. I value truth in science, and would like to know it, also regarding stucture of nuclei and...

Which is more correct, teaching the first two valence electrons as paired in the electron dot structure or teaching them as not pairing until forced.

The fine structure constant ##\alpha## is commonly cited as a very important quantity, because it gives the strengh coupling of the electromagnetic force. But it seems that the fine structure constant is not actually constant. It rather changes with the momentum of the (mediating?) particle and...

I have to do a Taylor expansion of the energy levels of Dirac's equation with a coulombian potential in orders of (αZ/n)^2 , but the derivatives I get are just too large, I guess there is another approach maybe? This is the expression of the energy levels And i know it has to end like this:

Homework Statement Draw this formula in line angle structure. CH3CH2OC(O)CH2CC(CH2)3CH(CN)CHO. Homework Equations None. The Attempt at a Solution I'm confused with the CC(CH2)3 part of the condensed formula. I knew I got it wrong the first time I drew it because I couldn't just tag three...

Hello everybody, while I tried to understand the Rubidium level scheme, I realized that I have some issues concerning the energy levels in general... If in addition to the orbital Momentum the spin momentum of an electron is considered for example the p level splits to the 2P1/2-level and the...

Suppose we have an energized conductor say 10m above the ground, my understanding is that E Field at the ground will be 0 v/m. My question is, if we have say 8m tall steel tower approximately 3m from the energized conductor and grounded. What is the electrical field on this grounded steel...

Hello. I have an object that I want to talk about. The object above does not seem to have numbers in a definite pattern, so, I think that this object will not have a single equation that describes the object, but instead there will be multiple number of equations of 'y' in 'x'. Correct?

In quantum mechanics time evolution is defined via a unitary operator $$U(t^\prime,t) = e^{-iH(t^\prime-t)}$$ Now let's forget about the fact that we know this exponential representation and that we know that the U's fulfill the group axioms, i.e. that we can multiply any two U's, regardless...

Homework Statement Hi everybody! Here is the problem: Hyperfine splitting of Deuterium Balmer alpha line: Consider the ##3p_{3/2}## to ##2s_{1/2}## transition in deuterium. Find the number of transition lines and their frequency shifts with respect to the transition without hyperfine...

I am reading "Abstract Algebra: Structures and Applications" by Stephen Lovett ... I am currently focused on Chapter 8: Galois Theory, Section 1: Automorphisms of Field Extensions ... ... I need help with Example 11.1.10 on page 560 ... ...Example 11.1.10 reads as follows: My questions...

Hey all! Undergrad in M.Eng here, building a desktop robotic arm (<12 inches tall, arduino board) for a personal project. I've been looking at materials, and aluminum and wood are both doable, but if possible I'd rather use a lighter material that I can cut without machines, such as a strong...

Homework Statement The problem is, calculate the energy and displacement of the structure. What is the displacement (y) in the middle of the beam? See drawing and variables in attached PDF file. Homework Equations See PDF file. Important: To form the moment function M(x), I use delta...

Hello everybody, I am currently working on desinging a tool, and I would like to get your advice on how to increase it's stiffness. The tool will be used for correct positioning of a component. It consists of 2 parts : And

Forgive my ignorance, I am learning about topics like the geoid, geoid anomalies, gravity anomalies as it relates to lithospheric composition. In my studies, I repeatedly find talk of show wavelengths and long wavelengths having different effects on crustal composition. One example I can give...

I tried to treat FCC lattice with a lattice constant a, as a monoatomic lattice. The reciprocal lattice is a BCC with a lattice constant 2pi/a. And the structure factor is 1. But I can treat FCC lattice with a lattice constant a, as a simple cubic lattice, with 4 atoms in each unit cell. As one...

Homework Statement http://i.imgur.com/Jt3u2uo.png Homework Equations octet structure bond strength bond order The Attempt at a Solution I have no idea why the answer is b... after reading the book... thank you.

Hi everyone, I am new here... please forgive me if my posting is imperfect :p I am planning to purchase a glass aquarium with tank dimensions: 48" (Length) * 24" (Depth) * 22" (Height) I wonder if a wooden stand with only edge support will be able to withstand the weight of the filled...

I am wondering if anyone has determined by experiment or calculation at what rate or even better what frequency the quarks move around at inside a neutron and proton? Do neutrons or protons vibrate at a specific frequency.

Homework Statement Consider the binary structure given by multiplication mod 20 on {4, 8, 12, 16}. Is this a group? If not, why not? Homework EquationsThe Attempt at a Solution I started by constructing a Cayley table, and working things out. It turns out that 16 acts as an identity element, 4...