Structures Definition and 350 Threads

I have uploaded the picture of the structures because I couldn't figure out how to type. Its vinyl chloride. According to me the order should be I>III>II because I has no charge so it must be most stable in II we have Cl an electronegative element bearing positive charge which makes it...

Hello, The problem I came up with deals with the structures that can be obtained by joining squares side to side or corner to corner. Specifically to this problem, structures, that are symmetrical to each other, are regarded the same. Ideally, I am looking for a formula that will tell how many...

Specialized 3D printers can now produce small optical elements: Described here. There is also a company that makes light shaping diffusers (for lamps) that control the light by controlling the interference patterns of the light due to microscopic structures on the surface of the diffuser film...

Hello everyone (and sorry for my average english), I have to make a report on an energy harvesting system from vibrations with piezoelectric elements. During my research, i always read that there two cases in a piezoelectric harvesting system which are : weakly coupled strucutre and strongly...

Homework Statement Homework EquationsThe Attempt at a Solution [/B] As this is an indeterminate structure with degree of redundancy 2, I have released support B & C. I then draw the BMD M0 of the Primary structure as well as BMD m1 and m2 of unit load system acting on B & C as follow: I...

It appears the oldest structures don't go father than 4500 BC. I was wondering if it's possible that were are structures that go beyond 4500 BC that we just haven't discovered yet? I doubt that there are buildings that can last for 500,000 years before falling down. However, is it possible that...

Hi There, My apologies, there was an error...in a previous question, which I POSTED ....last week. This question has now been withdrawn, & replaced with the following : ----------------------------------------------------------------------------------------------------------------- a) Show...

Hi, Maybe someone remembers how to determine the necessary conditions for a static structure to be stable and not to roll over. I know about the method when you imagine the structure has been rotated back an forth, and depending on how the center of mass takes higher or lower state the...

I suspect this is either amazing, marketing manipulation or crackpottery? "Scientists studying the brain have discovered that the organ operates on up to 11 different dimensions, creating multiverse-like structures that are “a world we had never imagined.”...

https://phys.org/news/2017-01-cosmologists-closer-quantum-gravity.html Researchers from the University of Portsmouth have revealed quantum imprints left on cosmological structures in the very early Universe and shed light on what we may expect from a full quantum theory of gravity. Dr Vincent...

I'm in Cegep in Canada, which is basically between high school and University. I strongly liked chemistry in the past, and I was very strong. Last semester, our chemistry class was Chemistry of Solutions (covering equilibrium, kinetics, acids-bases, etc), and this semester we have to take...

Not sure if this is the best place to ask this question but forums on this seem to be limited, can anybody explain how one would discover if a steel pole lighting structure is being effected by harmonic resonance? I do not know what tools and methods would be used, if anyone can provide some...

Hello, I am The Maker. I am here because I want professional feedback on my work. I have been building things with K'NEX and popsicle sticks since I was little and as a future engineer, I wanted real engineers to evaluate my potential. Please be honest, I am trying to improve my engineering...

Hello, Sorry if this is a rather basic question, but my memories of solid-state chemistry are a bit rusty. Basically I'm trying to predict new crystal structures. I understand the crystallographic aspects quite well and know that at given external temperature and pressure the most stable...

We were going over the structures of crystalline structures and the professor seemed to struggle to represent it nicely in 3D. I'm not sure if it is a common problem for students (I didn't think it was so hard to picture), but I decided to make a 3D representation of it that I thought would...

Has somebody a paper, text, (whatever), which explains the Lagrangian Coherent Structures ? I want an explanation by words and not all the mathematical stuff. All I can find about LCS is 1. They organize flow 2. you can detect them with the Lyapunov exponents. But I want to understand what LCS...

Hi, I was wondering which course will be more beneficial to take first for a first year student majoring in computer science? Note: I tend to dislike proofs and theories. Discrete Structures - An introduction to the basic concepts of statistical analysis with special emphasis on engineering...

After Dark Energy will tear our Universe apart, every Hubble sphere would contain only 1 or 0 gravitationally bound structures. What is an average size of such structures? (As I understand, galaxy clusters are the "seeds" of such remnants?)

I've been looking after some good books dealing with structural engineering of rockets and spacecraft s in general. I know that Rocket Propulsion Elements is a good book on rocket science, but I'm looking not only for propulsion but more specifically for structural design (loads, stress...)...

Hi, Just curious if someone knows of any Characteristic class used to determine if a manifold allows a Complex structure? It seems strange that Complex Space C^n is topologically Identical to R^{2n} yet I believe not all R^{2n}s ( if any) allow Complex structures. Thanks for any comments, refs...

What is the effect of a high frequency, where high is say 1MH to 100MHz on a bar of steel say 1 foot in length? A GW passes at the speed of light with a wavelength much longer than any acoustic response of the bar and well above any resonance. Intuitively (which I don't give much weight in this...

Homework Statement Given connected, directed and weighted (positive weights) graph. Find the shortest cyclic path for each vertex. Cycles have back edges and can also be self loops. 2. The attempt at a solution I need some clarifications for this problem related to implementation in C. After...

So from what I seem to understand up until now, Maxwell's equations usually work while assuming that the fields are continuous and smooth instead of the actual complexity at the atomic scale. However, as we move more and more towards the microscopic realm, a point comes when we cannot ignore...

Hi! I am looking for a textbook that explains/describes for moving mechanical structures (such as linkage mechanism, engines, ... and not buildings, bridges, ...) the stresses, deformation, wear, temperature change, ... due to operating. E.g. Linkage mechanism: what are/defines the stresses...

Homework Statement So I'm getting an error when I try to compile my C++ code: Debug Error Abort() has been called I have commented the code reasonably well, but the idea of the program is to take a file, separate the contents in each line to a part of a structure containing: Product Lookup...

Hi, everyone! I saw this on Phys.org and thought it was interesting. Any comments?

i know that a node cannot have more than one parent given that these parents have common ancestor (because this is undirected cycle and a tree must have no cycles). but can a node have more than one parent given that these parents don't have common ancestor (which will produce an unrooted tree i...

So, like the title says, I'm doing another project. The kicker this time is that I don't even know how to start. Last time I was able to post some code I had already messed around with (and messed up) but this one I'm not even sure how to begin. I've already done some of the work with...

I've been searching for a while, but all the knowledge related to this field seems to be developed on field, so, does people here has any data related to such kind of repair ? I'm mechanical engineer whiling to relocate my field of actuation to this area, repair and reinforcement of structures...

Homework Statement Homework Equations number of alpha hydrogens= number of no bond resonating structures The Attempt at a Solution option 1: 3 option 2: 6 option 3: 8 option 4: 9 So the answer should be 4, right?

Hello, I was wondering, if the de-Broglie-relation for particle waves already includes relativistic effects? Suppose I want to resolve an atomic structure of about, say, 0.1 nanometers. For an attempt using particle waves I would need a certain momentum p=h/0.1nm, at least. Now comes the...

Hello there, In this semester I'm studying the vibrations course. In this course we get questions like calculating the total stiffness, set up differential equations and so on. The book that we use (Theory of Vibrations) has not been very useful, our exams give beam spring structures related...

Homework Statement Explain and compare two efficient implementations of a priority queue using binary tree. Ilustrate this on an example of ascending priority queue that is created when elements 15, 38, 45, 21, 8, 55,20 are inserted and the two largest elements are deleted. Homework Equations...

i have a simulation problem about a fuel assembly, after running this warring pop up:- " non-lattice cell in lattice universe "; and visual editor crash with one warning message " warning. 2 surfaces were deleted for being the same as others." So, what may be the problem with the input?

Homework Statement Write a program that reads data about n number of books. Sort data about books lexicographically by title (if the title is the same, sort by publish year), and then for every book sort data about authors. Then, read name and surname of one of the previously read authors, and...

Homework Statement What are simple molecular structures?Homework EquationsThe Attempt at a Solution Simple molecular structures consist of molecules containing fixed numbers of atoms joined by strong covalent bonds. I'm getting confused with all the different structures in chemistry. How...

Homework Statement Homework Equations Tree data structures. I think it might also have something to do with minimax algorithm, but it was only mentioned once and never discussed extensively in class so I doubt it is required. The Attempt at a Solution [/B] If both players play as well as...

so I am hatching an idea for a system of equipment which requires a focussed wavelength which will not greatly widen over distances of less than a mile. Also the waveform needs to be sensible by receiver antenna or something of a similar nature. It is necessary that the waveform be able to...

I read that vinyl or aryl carbocations do not have resonance stabilization but I can't understand why that is the case. Below I have drawn some resonance structures for aryl and vinyl carbocations: Aryl carbocation: https://imgur.com/QwiHJg8 Vinyl carbocation: https://imgur.com/rKBs57d In both...

So I get that when starting at Eigenstate A all super-positions wave functions are collapsed do to entanglement with "observed eigenstate A. My theoretical question is since sub-atomic particles are entangled in there "eigenstate" space-time positions, wouldn't that mean that complex structures...

Hello, I'm a student in mechanical engineering and right now, we're studying non Linear Calculation of Structures. We have a project which consists on evaluating one of the solutions to stop a tourism aeroplane CESSNA 172, like a cable to stop it when it lands. So we started our study with a...

What books of solved problems (free in pdf) would you recommend for data structures and algorithms in C (linked lists, trees, sorting and searching algorithms, graphs, recursion, files)? Note: I am not looking for theoretical books, but books of solved problems. Thanks for replies.

[PLAIN]http:// I am having trouble with this truss problem. I have attached my work so far. I used the entire structure as a system first and did the sum of the forces equals zero but I don't know how I can finish the moment at a because I don't know the x and y distances for the 500N force...

Homework Statement Look I have an exercise about trusses in vector mechanics. It's the following: https://scontent-lax3-1.xx.fbcdn.net/hphotos-xfp1/v/t1.0-9/12003339_1645511085733429_8210043018491702007_n.jpg?oh=4955534403fb6f3f5f9a40c9c0b8ecbc&oe=569761ED I have to determine the forces in...

So, I'm a fellow civil engineering from Portugal pretending to get a masters in structures. Would like to hear some opinions on getting a masters from an university out of my country, becasue sadly, in Portugal, there a are very few jobs for new civil engineers, and the ones we got are mostly in...

Hi, I have to make a project for school about the topic on the title. It must be a personal work, i mean i can't choose a difficult subject cause then all my presentation could be just a simple documentation. Also, the project could include just one or two of the topics in the title. I thought...

Hi people of this forum, I have a serious issue at hand right now. I am currently a 3rd year Bachelor student of the Aerospace Engineering at SRM Universty, India. I will be entering my Master's in Aerospace Engineering at the University of Dayton in the fall of 2016 under a Dual-Degree program...

I'm beginning a science fiction novel that begins a billion, or possibly several billions, of years in the future. Given the best quality structures humans can make out of the longest lasting materials we have, what would buildings and other structures look like after that long of a period of...

Thank you for taking the time to stop by this thread. I am in a Computer Science Engineering course and have just finished my first year. I don't think the first year was very fulfilling in terms of quench in my thirst for knowledge. But that's alright because it was largely unrelated to my...

Like asteroid clusters or any kind of what-not thought to be part of our solar system?