Structure Definition and 1000 Threads

At first I tried solving the problemteh following way: Due to symmetry let the rods connected to the green rod have tension forces in magnitde T1 => mg = 2T1cos(a), where a is half the angle formed by the two rods. From tere I got an expression from the longer rods in the force projected by them...

Homework Statement:: Does Sars-cov-2 Virus have Reverse Transcriptase enzyme for its replication purpose? Relevant Equations:: None I surfed Google for a relevant answer to my query but failed to find one.I just want to confirm whether Sars-cov-2 has the Reverse Transcriptase or...

When we shine an X-ray beam on a crystal, according to Van Laue formulation, for a sharp intensity peak to be observed on the screen there is a specific direction ##\mathbf{\hat{n}}## , in which for all the X-rays with wavelength ##\lambda## and wavevector...

I have been studying overloading [ ]. I understand how it works from the book. I experiment using vector of structure and obviously I can't make it work. I wonder if it is possible to overload [] on vector of structure. Here is what I have and it's not even close to working, what can I do to...

Out of sheer curiosity, would a polymer of the following structure be theoretically possible? Imagine that the "N-methyl" groups are just the bounds of what is shown, and not actual carbon-containing substituents... It doesn't seem to break any elementary bonding rules. However, the C-C bond...

FOOF looks like this: This paper suggests that FOOOF also exists but does not give a structure, although it does state that it's unlikely it takes the F-O-O-O-F structure. "Ignition: An informal history of liquid rocket propellants" claims that this series of compounds, up to FOOOOOOF, can...

Hello! Springs are amazing devices: we take a straight piece of metal wire, we change its shape and get something that can compress or extended a finite length. We could not do that with the straight wire (too difficult to move atoms apart or close to each other in a significant way). Why does...

Hi, I tend to write down questions/thoughts that come to me as I read articles that are interestsing. I'm reading the intro to solution state NMR in a biophysics textbook. Any there any purely theoretical approaches to determine protein structure / dynamics ? The 1 dimensional digital code...

Edit: nevermind, I realized my mistake. Corner atoms don't touch in FCC, so there's just 4 neighbours in each plane which sums to 12.

Hi I have a funky problem I have been working on for over a day, it is supposed to be quite simple, but I have funny result. What the program does is to pick out one of the five records(of structure) stored in the file, modify it and store back into the file in the same position. It supposed to...

Hi, I have a Matlab code for calculating the band structure of graphene nanoribbon which is working fine, but I wanted to convert it to python and I've done it. I guess I made a mistake somewhere because the plot is totally wrong. Could someone check it for me, please?

Hi I am working on Chapter 11 Structure, this is pointer of structure where the structure has a member that is a pointer variable. I just want to run by you guys to make sure my understanding is correct. Below is a program I wrote for verification. It works...BUT I afraid it's like last time...

Precision Microwave Spectroscopy of the Positronium n=2 Fine Structure A nice compact abstract, so I'll just quote it here: Positronium with its two light leptons is the dream of every theorist, that keeps the uncertainties small. The 0.61 MHz experimental uncertainty are the sum of 0.57 MHz...

Dear FEA experts, I'm trying to model the mechanical behavior (static, modal, and buckling analyses) of an underwater floating structure (e.g. submarine capsule or buoy) under hydrostatic pressure by Finite Element Analysis. To obtain feasible results, the structure should be modeled as freely...

Here is the full question. I have already tried to answer the questions and have put a red dot next to the answers I think are right? Here is my working out to get the answers I had above Have I done this question right? Sadly I don't have the answers to check for myself here so I'm...

I'm 3d-printing a part that is 110mm x 40mm (XY-plane). I have to keep it light weight, so I made it thin - 0.6mm (Z direction) and filled the surface with holes to remove as much weight as possible. Then I added a grid of 2,5 mm high "walls" in the XY directions to make it stiffer and a couple...

I have a quesrion about forming the eqaution of moment equilibrium. As shown in the picture at cut 1 there are 2 vertical forces and a bending moment. I expect V=A. If I apply moment equilibrium about the point where the bending moment is, we get that Ay*x = M(1). But how about if I take moment...

an element (we will call it X) got a cofiguration of 1##s^2##2##s^2##2##p^6##3##s^2##s##p^3## what molecule is moste likely to happened between this element and Mg? 1.MgX 2.##Mg_2##X 3.Mg##X_2## 4.##Mg_3## ##X_2## how do i do it?with lewis structure?just check what structure makes the most...

Is this the correct lewis structure for CH2O?

The Example 2 at this site ' http://ocw.ump.edu.my/pluginfile.php/1435/mod_resource/content/2/Chapter%205%20%E2%80%93%20Three%20Pinned%20Arch.pdf ' (page 14): It is parabolic hence the equation is y = (x^2)/10. I used the section method between A-D and applied equilibrium of moment to find a...

When modeling stellar structure and formulating equation of states, I've seen various cases where you have to take into account whether the constituent gas of a star is degenerate or not. But how do you determine if the gas is degenerate or not?

Hello, everyone. :) All I could gather is that, if I'm correct, lattices are spans of the column vectors of the matrix within the "LAT()" notation and the X and Y occurrences are unit placeholders (such as the pixel unit (since this is in the context of image processing)). And, as an attempt...

I have observed a layer like structure (made of plasma) in a cold plasma and wonders what causes it. Following image shows the observation.

Basically looking to find out what the maximum amount of load you could put on the center of a structure like this would be, in theory. Top Beam: The top "Beam" of the assembly in the drawing is 3"x 3"x 3/8" square tubing, 112.5" long Supporting Beams: The beams supporting each end of the Top...

There seems be much understanding of the internal structure the Sun for instance its several layers,thecore, the radiative and convections zones, the corona and so forth. What is known about stars that are not like the Sun? I was particularly thinking blue or red super giants.

Why the air splitted at point a of aeroplane wing's cross section meet at point b simulatneously,

A massive rocky material that is connected open-cell, macro-porous at surface, but 'vesicles' shrink to closed-cell then solid as you drill deeper: What's the technical term for such ?? == Writing a SciFi tale, I'm trying to describe a large, alien-ish rock formation. I've a vague recollection...

The problem of interest at the moment is the solution of a simple damped oscillator problem, xddot+2*zeta*wn*xdot+wn^2*x = 0 Everything seems to work fine provided I include the values of zeta and wn inside the function that defines the derivative values. But zeta and wn are actually calculated...

Summary: The Space Between the Nucleus and Electron Shells? What composes the space between an atom's nucleus and its electron shells?

how can I determinate the electronic structure of a multiband system? for example in the case of the superconductor BaFe2As2 , the electronic properties are as known dominated by 5 Fe d states at the fermi energy, so 5 bands cross the Fermi level and form 5 Fermi surface sheets (if we consider...

Hello All, I am designing a robot that has these dimensions, I need to work out the torques around T1 to T6, I am unsure of the best way to do it, ie do I do a net torque calculation around the torque to be found or is there a better way. W1 to W4 = 0.53955 kN W5 = 14.44032 kN W6 to...

Suppose you have a liquid with high potential energy at a height [H] in a first moment. In a second moment, the liquid loses its potential energy (that is converted into kinetic energy) and fall in a cylinder at height [h] .IF the liquid is incompressible what happens with the molecules in the...

Hello, From wikipedia, this is the partition function for a "classical continuous system": This is the pillar of classical statistical physics, but it can be seen as a mere kind of "mathematical transform" . It can be used even without thinking to statistics or temperature. If we focus only...

first of all, I tried to obtain the energy eigenvalues of the Hamiltonian, by using the equation ##det(\hat H -\lambda \hat I)=0## ##\gamma V\delta(z)(\hat z \times \mathbf{p}) \cdot \sigma=\gamma V\delta(z)(p_x\hat j-p_y\hat i)\cdot(\sigma_x\hat i + \sigma _y \hat j)=\gamma...

I am reading Karl R. Stromberg's book: "An Introduction to Classical Real Analysis". ... ... I am focused on Chapter 3: Limits and Continuity ... ... I need help in order to fully understand the proof of Theorem 3.18 on pages 98-99 ... ... Theorem 3.18 and its proof read as follows: In the...

Hi all. I'd personally consider the De Broglie wavelength λ=h/p, with p being the momentum of the electron beam. I get $$\lambda \simeq 0.6 \times 10^{-18} m $$ and since the radius of a quark is ## \leq 10^{-19} m ##, the proton structure can't be resolved. I'm quite sure there's something...

How does " an axis normal to the plane containing the structure" look like?

How much impact does the presence of the cosmological constant have on the formation of structures in the universe? On a larger scale, is there less structure formation because of the presence of the cosmological constant?

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I understand that the intrinsic spin of an electron causes discrete differences in energy for transitions, due to the interaction of the magnetic dipole moment of the electron. Also, that this in turn creates the fine structure spectra. But what I am currently struggling to picture is why this...

So given a force F that is at r1/2, distances y, r1,r2,and r3. What is x?

Hello, we are studying potato periderm before/after digestion and dewaxing and native vs wounded. One of the techniques is XRD, hence my user name. Among other things we are trying to use XRD to determine the arrangement of fatty acids, esters, and other long-chain aliphatics that are present...

Problem Statement: What's your result of ##X_A##? I find mine is different from the standard answer. Relevant Equations: My answer for $$X_A =5 kN$$ Problem Statement: What's your result of ##X_A##? I find mine is different from the standard answer. Relevant Equations: My answer for $$X_A...

I've been adding some renderings I did of the M87 black hole on a different thread and was asked to elaborate on the source of this technique which was investigating images of the shadow of an atom. You can look up the original experiment on Google, as well as observe the final image. The...

How can I see, by looking at a band structure if the substance in question can be viewed as a free electron gas (FEG) or not? What characterizes a FEG in a bandstructure plot? Thanks in advance!

Over in the thread The eight-queens chess puzzle and variations of it | Physics Forums I discovered that with a toroidal board, one with periodic boundary conditions, the amount of symmetries becomes surprisingly large (A group-based search for solutions of the n-queens problem - ScienceDirect)...

Hi! I never really understood band structure diagrams. I think they represent the energy of an electron, with the given circumstances, at a k vector. Are the electrons only allowed to be on the lines here? Or can they also be in areas enclosed under/between certain lines? What are some...

Is there a text, or set of texts, on how to predict what frequency of photon is released when a particular molecule is brought to an excited state and then relaxes? So for example if you were to put, say, benzene into an electrical tube and excite it what frequency would be released and more...

I'm not sure if this is the correct thread, so please accept my apologies if I've posted in the wrong section. My question is for meteorologists and atmospheric scientists who did their undergraduate degree in different, but related fields, such as physics, chemistry, Earth science, etc. and...

Hi, could you please explain me, how to copmute the yellow parts? Thank you very much.