Engineering

MORE INFORMATION ABOUT NDE RESIDUAL STRESS The residual stress in a metal do not depend on it hardness, but from the module of elasticity or Young module and from its chemical composition (density). The hardness of a metal indicates its ability to absorb energy elastic, plastic or kinetic energy, but through it not possible to determine the value of residual stress. In a metal with the same hardness we will have a different values of this stress. Therefore, the problem will be to measure the values that vary so exactly proportional to the residual stress values in a given metal. The residual stresses tend to equilibrate themselves in the surface of the material. …

Do you think a Stirling motor can be used to power a small automobile with at least one person inside? Im guessing that with me in it, plus the motor and the body Im drawing out, it will be about 160-180 pounds. Could a stirling motor push that much on wheels do you think? Ive been wondering this question for a while. Im currently making my own stirling motor, and am wondering If you guys think If It would work or not. I beleive that It will, and I will probably still try even If Im told It doesnt work, why not. Im not so much worried about speed, just so long as Its a bit faster than walking, Im cool with it. Im tired of walking 1&1/2 miles to school twice a…

Which of field engineering is most useful & demandable in todays world? Merged post follows: Consecutive posts mergedI think so energy engg. & mechanical engg.

I want to bend some resistor wire into a coil shape and then insulate it electrically. However, the coil will be used to stir and heat liquid so the material must not insulate the heat from the resistor wire. I would also like to experiment with this at home so can it be achievable in a DIY sense? The coil will be no bigger than a hand-held whisk (just for an example of size!) Any ideas welcome Thanks Paul

Is there a material(preferably some sort of clear or white crystal) that will give off light when exposed to low levels of heat(like body temp)?

wasn't sure if this belongs in this section but its here now.. To be clear, this isn't a fanatical thing or talking up the movie. I like most of the more recent movies for what they are, movies, but they have a very logical and real use of the possible technologies we are looking at. wouldn't think I am the first one to think of this so direct a link if anyone knows of anything related. existing technology, ideas, theoretical ideas or trialed technology, etc... the question for discussion is, with the idea that the power source was possible now, in what ways would a suit similar to that in Iron Man be made? in relation to the mechanics of the movement of it,…

Hi everybody I have a question about a solar-assisted cooling system ,used to cool milk The systeme basic components are electric compressors and an absorption machine, When optimizing the compressor cycle, by lowering the temperature in the condensor, an important saving of energy can be made...........this lowering is the result of introducing the absorption machie ............; my question is: how does the lowering of temperature in the condensor influence the electric energy consumption? i mean how could it be calculated? for instance, if the compressor cools a volume of water at 7°C (instead of 9°C) to bring it to 2°C (knowing its capacity (2500kw) effi…

Alright, so I want a small, {inch or two}, sensor of some sort that, when bumbed, {just slightly}, sends out an electrical signal. What should I use and how much is it? Thank you.

Me and my friend have gotten into sword dueling...not serious dueling, we just pick up a couple of sticks or something and see who can hit the other first. Anyway, since I've always been a with Star Wars fan, lightsabers have always captured my attention, specifically how to build one. And ever since we started dueling, I was attracted to the possibility of making a training saber. The way I envision it, it would basically be a piece of metal with some kind of voltage going through it, so that it would give a jolt whenever it came in contact with skin. It would certainly make the match more fun, since the opponent would have to guard himself even against the smallest brus…

you want an object to reach as high as possible in the atmosphere, if it reaches space, even better... how can you do that while attaching it to a balloon? this includes a lot of physics and design, maybe even chemistry, but a LOT of innovation..i have some ideas, but wanna hear yours first.

i am constructing a glider made from biofoam which is flexible and weak in structure and i have made wing of 30cm from that foam.now i should make it stronger by reinforcement with any strong material.what are the choices?

Hey everyone, how's it goin? I have a question. I was reading this article earlier: Link changed to original article http://www.eurekalert.org/pub_releases/2009-04/esa-gei040609.php It's talking about an electric ion propulsion engine. Does this really work? I mean seriously, I thought in order for something to move in space it had to have something to push against???!!!! For real, how does electricity push anything in space? Can someone please explain this for me -SCIFOR

i want the bullet to do high penetration intense damage high velocity wat to do

Hello, I have a project where i need to design a heat exchanger (HE) to reduce the temperature of hot air. The hot air comes in at 700K with a pressure of 1300Kpa, it will come out of the HE with the same pressure but how do i calculate its exit temperature? I know it has something to do with the HE Efficiency, which i do not know how to find. HELP!

First post! Yay! Okay, if you work with nanowires, here's the short version: What methods would you recommend to get them off of the substrate? If you don't work work with them, here's the long version: I grow nanowires around 10 microns in length and 200 nanometers in diameter perpendicularly out of silicon wafers. I then put a layer of PDMS on top, which coats them on top and in between. What I need help on is getting them off of the silicon substrate so I have a bunch of nanowires embedded in PDMS. This is difficult, of course, because of material size and the fact that the nanowires are more strongly bonded to the substrate than to the PDMS. So far, my b…

i'm a production engg. my area of interest r robotics metallurgy operation research mechanics plz someone give me a idea

I've been thinking about switching to a motorcycle because of the fact that they're so much cheaper (both to buy and to maintain) than cars. Well, I've found a nice one here. http://www.hondaofrussellville.com/new_vehicle_detail.asp?sid=03165247X7K11K2009J9I15I55JAMQ2743R0&veh=3424&pov=1184862 I know it doesn't exactly look "macho," but that's the last thing on my mind. Judging from those specs, what do you estimate the fuel efficiency for a 240lb driver would be?

Hi, Could someone please explain me what this component from the drawing means? This is taken from here: http://www.fas.org/spp/guide/china/launch/lm2c/Image2190.gif http://www.fas.org/spp/guide/china/launch/lm2c/2C_Chapter5.htm

Hello. Slowly pouring water onto a very, very hot vessel so there is instant steam production; how is that method called ? -It is not 'flash' distillation- Miguel

One soaked black towel, made of 100% cotton in same test conditions as another black 'towel' made of 100% nylon; under the sun... Which one would evaporate/dry more rapidly ? -Or is there any other better material choice with the same texture- Miguel

hi, i m new to simulation of MANET, is there any priority for Route Request,route reply in Data link layer. because lower layer will consider as the data of the upper layer control packets. pls reply me.

Can we compress gases using ultrasound produced by piezoelectric crystals? Will the vibrations compress the gas column? What will be the excitation voltage required to produce ultrasound using piezoelectric crystal?

Hi ya guys, Here is my question: In a coil with some DC current, one can think of all of the electrons moving inside as a cylinderical electron cloud, spining around the cylinder's axis. Is it equivalent to think of the self induction of a coil as the angular momentum of this electron cloud? The coil's resistance to the current's change is analogous to the resistance of an object's angular momentum to change. What do u think?

I'm trying to build an alternator/generator that has the magnets rotating inside a coil of wire (or stator) to produce HIGH AMPS at LOW VOLTS. So what causes amps vs. volts: number of coils, magnetic field strength, rpm's, what?

Imagine you wanted to send a message to your future relatives, a few paragraphs of information. Thing is, these relatives won't exist for 1 million years! How would you construct a container and place information in it that would exist intact for 1 million years? Rules are; -Has to stay on Earth -Must be self contained (no helpers looking after it) -Money is no Option -Must use available technology -Message can be of any type of material or construction/form etc 1. What materials/technology would you construct the box out of? 2. What materials/technology would you construct the message out of? :-)