Structures Definition and 324 Threads

I was asked what a bundle structure is in a PM. I'm posting my reply here, to give others a chance to add comments. I didn't get to see the exact sentence in which the term "bundle structure" was used. I would guess that it was used informally to say that some smooth manifold is the total space...

This is a concept I have never really understood. I mean to say is how can we include such a thing in a theory? How can we use them if we know that they don't actually exist? Are they some sort of calculation tool?

For violet phophorus,it seems that the crystal structures given by two websites are not the same.In Openstax CNX,the link is http://cnx.org/contents/f46e8679-ee00-4073-9f5e-a87ca9955a9e@25.9:67/Chemistry_of_the_Main_Group_El and the Figure 12 displays it as follows: But in Chemwiki,the link is...

See attached image. I have never heard that before. Why wouldn't one be able to implement a data structure that stores a matrix by its columns using C? Is that true?

Hey! :o I have the main function of a program in a .c file. The main function uses data structures which are defined in an other .c file. And the main function uses also a .txt file to get some inputs. Is it possible to run the program if the main function is an other file as the definition...

Here attached is a question from my exam. My TA removed 1 point out of 7 for a reason. Can anyone decipher for what? There's the writing in red but it is illegible to me. I don't understand to what he refers by 8 and 6 t or +, or whatever he wrote. http://imgur.com/igpyp8V Or can anyone write...

Hello, There are three different orders of traversal that we learned about ##\bullet## pre-order traversal ##\bullet## in-order traversal ##\bullet## post-order traversal Anyone know of any easy ways of remembering these 3 and how to order them? I have posted my lecture slides, but I could...

Hi, I'm an engineering student in Civil/Structural engineering and am interested in structures. As well as fixed structures I am also interested in mobile structures like ships. Can I get a job designing vehicle structures after graduating from a degree focused on civil structures? Would the...

So i have a book that covers the fundamentals one needs to know before starting C++. I'm self teaching myself so i don't have to take the intro programming class at school. Anyways, our professor sent us all a email that among a few other other topics (such as arrays and functions and loops), we...

Please look at the pictures. I do not understand why they have not included the resonance structure for that molecule for which all the double bonds are displaced is not included.

Homework Statement In general, when presented with a problem such as write out all the primary alcohols/amines/ketones/aldehydes with this formula ________, how do I actually go about systematically figuring them out? I have seen problems with up to 8 different structures for me to figure...

Homework Statement Are these structures equivalent? Here's the professor's rendering: http://i.minus.com/jnojtCx6wYvqD.png The Attempt at a Solution Here's my rendering. The molecule is 1-chloro-2-ethylcyclohexane. I had projected the chlorine out of the page and the ethyl group into the page...

Hi All, Greetings..! I am a master student in nanoelectronics from India. I wish to know how to generate nanostructures (for example as shown in figure attached) using programming (C/Python). Are there any algorithms or literature that discuss how some random structure of...

Homework Statement Is N triple bond O with a radical on oxygen a valid LS for the nitric oxide molecule? Homework Equations Max number of valence electrons in a shell - 2n2. Oxygen is in second row of periodic table. Max valence electrons: 2(2)2 = 8. The Attempt at a Solution I...

So 3 days ago I had a chemistry test and part of the test included Lewis dot structures. I counted my valance electrons and distributed them equally but I have no Idea why I got these wrong.The second one I know why I got wrong but the rest of them look fine to me. I would really appreciate it...

Hi everyone, a couple of technical questions : 1) Definition: Anyone know the definition of the induced orientation of a submanifold S of an orientable manifold M? 2)Dividing sets in contact manifolds: We have a contact 3-manifold (M3,ζ ). We define a surface S embedded in M3 to be a convex...

Interstellar travel is mostly a though experiment at this stage (although NASA will be launching the solar sail SunJammer in a couple of years). My question is a very broad one about what type of materials would be well-suited for structures to support interstellar travel. Any human habitat...

I was reading this article from Wikipedia on resonance structures: http://en.wikipedia.org/wiki/Resonance_(chemistry ) What I do not understand is, what is meant by potential energy in terms of chemistry? In physics, potential energy is defined by location in a force field. What is it that...

Homework Statement A structure is made of 3 members, AD, AC, and BD (as shown in the attached image). A and B are NOT directly connected. There is also a pulley attached to D with radius 0.15 m. 1 end of the cable is attached to a 500 N weight, the other on is fixed in a horizontal sense. A is...

In modern buildings (I'm talking about taller structures, apartments, etc. not houses) that have a reinforced concrete framework are the internal / external walls (usually brick, masonry etc.) ever load bearing? In the sense is the strength / integrity of the structure ever depending or...

My professor had given us a lecture on the RNA World Hypothesis. He provided evidence for this hypothesis by citing the in-vitro selection experiments carried out on RNA. The outcome of one (or more) of these experiments resulted in the "creation" of an RNA polymerase ribozyme which totally...

Hi, When drawing the resonance structures for ClO-, two exist. One where the O has a formal charge of -1 and there is then a single bond. The other structure is Cl with -1 for formal charge. Why is this second structure an equal resonance structure (why does the Cl have a negative formal...

I`ve started reading up and practically making various resonance structures of various molecules. Though in the book I am reading I have only been subsituted with the information that it can be very necessary for chemical mechanics later on in the book. Is this correct? Also, the book doesn`t...

I have been studying topology and abstract algebra for some years, and for a lot of time I have been having a hard time trying to understand the definition and concept of "preservation of mathematical structures". For instance for binary operators a Homomorphism is said to preserve...

How to find chiral centres of rings structures?For example take the following ringhttp://img203.imageshack.us/img203/7994/8vmq.jpg How to calculate no. of chiral centres?? thanks

Homework Statement I'm supposed to draw VSEPR structures showing all valence electrons for the molecule. Draw in the partial charges δ+ and δ- if they exist. Classify the molecules as ionic, polar covalent or non-polar covalent. Some molecules may be of hypothetical existence. Homework...

How does one interpret band structures (i.e. E,k solution pairs for a given Hamiltonian) for a non-primitive cell? I was looking at these slides: http://www.tcm.phy.cam.ac.uk/castep/CASTEP_talks_06/clark2.pdf Slide 9 has the "normal" silicon band structure obtained with a primitive cell...

I need to write the lewis dot structure along with the 3 resonance forms for CH3CNS. This is what I had but it was wrong. Not sure what to do. Thanks.

Except for the work of Torsten I am not aware of any paper which discusses these topics. Some ideas: 1) all theories for QG I am aware of do either use manifolds and smootheness (string theory, geometrodynamics, shape dynamics, ...) or are constructed from them (LQG, CDT, ...) 2) in some...

I am trying to understand what is meant when people say space itself is expanding. When I hear that, I imagine a 3-d Cartesian coordinate system in which every axis gets scaled at a given rate (like in an animation). What I don't understand is, if everything gets scaled, then how can...

URGENT ! Mathematical Logic and Structures Hey guys, i need a HUGE favor, i need the resolution for this 5 questions, its a question of end this year my degree or stay one year just with a subject. Please I am begging, who knows the resolution please say me something. Part 1...

URGENT ! Mathematical Logic and Structures Hey guys, i need a HUGE favor, i need the resolution for this 5 questions, its a question of end this year my degree or stay one year just with a subject. Please I am begging, who knows the resolution please say me something. Part 1...

Hello! Excuse me for my very basic understanding of math. I'll try and present my idea and problem clearly. I'd like to devise a payout structure for a tournament. 20% of the entrants will be paid. The payout will be an exponentially sloping function. The payout is in percentages that equal...

Attached is a picture of the truss. I am trying to calculate the member forces. I know a moment is = force * perpedicular distance, but in this case, for example, if i am taking moments about A, Would the equation be -(1*2KN)+(1*c) = 0 or using an alternative perpedicular distance...

I have seen many data structures like stacks, queue, binary search tree, avl tree etc. Except stack and queue do we actually use these data structure outside the field of computers? Suppose I want to store by books(or any other stuff) according to some priority I would not use a binary heap...

A cylinder is constructed from a super insulator. The dimensions of the cylinder are Length L: 1 M; inside diameter i.d.: 12 mm. The entire Length of the cylinder contains copper (cases described below). Heat (T > 100C) is continuously applied to the copper on one end of the cylinder...

Could we have close-packed structures with bases? Or, is it possible in close-packed structures that atoms of bases have arbitrary sizes? For example could we have a fcc close-packed structure with a two-atomic base (of any types of atoms)? If yes, what would happen if sizes of the bases be...

In molecular orbital theory, only the electrons are considered and from that we draw conclusions about molecular shape and such. I was thinking just now, what about the nuclei? If we apply QM to the nuclei as well, wouldn't that mean that we can't know where the atoms are? or is the...

Hello, I am having difficulty discerning which resonance structures are considerable enough to include and which are so unimportant that they should be discarded. There seems to be no general rule on this that I can find, so I was wondering if such a rule existed or if someone can lead me in...

I am not a theoretical physicist but I have heard of Schrodinger's cat. It is a fact that stresses and strains measured along a structure are directional i.e the stresses and strains vary according to the direction you orient your strain gauge in. Does this have any connection with the 'observer...

On all manifolds dimension 1-3, there is only one differential structure per manifold, yet in higher dimensions it seems to follow no pattern. Is there a physical reason why you can construct a certain number on any given dimension? Also, what is it about dimension 4 that is so strange? Using...

I have written a C program that produce a structure, give it's elements their initial values and change these values when neccessary.I can compile my program but when I try to run it,error:"segmentation fault(core dumped)" appears.I commented different parts of my program and I underentood the...

Would I be in over my head taking COT3100 (Computational Structures) before taking COP2220 (Computer Science I)? Here are the catalog entries for both: COT3100: Prerequisite: MAC 2311 (Calc I) or MAC 2233. Applications of finite mathematics to CIS. Sets, relations, functions, and number...

How to "amalgamate" a family of structures? Given a collection of structures all using the same language, is there a way to come up with a structure C such that each given structure is, in any sense, a "subobject" of C? Right now I'm looking at coproducts to see if that will help. Please...

"In the minutes following the explosion, protons and neutrons collided in nuclear fusion reactions to form hydrogen and helium." I found this bit of text in an article...and it got me thinking. What were the conditions the first atoms formed? Further more..what were the conditions that...

why don't we see wind harnessing structures (like tiny fan-like structures) mounted on vehicles to capture the relative motion of the wind against the moving vehicle? I had one guess that mounting such structures would increase the surface area of the vehicle and thus the air drag acting on it...

Hey guys, let's say I were to define a new mathematical object, a novel type of number for example, and I am trying to determine its various properties (arithmetic, exponential, logarithmic, etc). Now, let's say I am able to use these numbers to produce solutions that agree with expected...

Hi, suppose I want to look up the crystal structure of a pure element (for example, the structure of pure Tellurium), is there an online database or reference to easily find this information? Thanks.

I am an undergraduate student studying Computer science and engineering (2nd yr). I have studied the basics of C programming and have started studying data structures. But I find it oddly difficult to get hold of a good book that explains basics and the algorithms used for various data...

I've written a code for the problem but I'm contantly getting segmentation fault, core dump error, kindly help. I'm using gcc from ubuntu 12.04, Here is my code... #include<stdio.h> //#include<conio.h> #include<stdlib.h> struct node { int ind; int ele; struct node *next...