Engineering

I was reading a story on msn Canada that claims automatic transmissions are much faster than manual transmissions So I am wondering why do race car drivers prefer manual? In my time at the track (drag strip) it seems all the pro mods had manual transmissions I think Indy cars also do. So is the claim wrong that automatic transmissions are faster? Is it hard to modify automatic transmissions for custom gear ratios or somthing?

Good evening! Could anybody inform me in which circumstances the reynolds number takes low or negative values? Thank you!

How to solve following five questions in the picture?

Hi all, this is how my lecturer derive exergy: 1st law efficiency=W/Q Carnot efficiency=(T1-T2)/T1 W/Q=(T1-T2)/T1 W=(Q*(T1-T2))/T1 The W above refers to useful work. My question is, when we formulate the 1st law efficiency, do we have in mind that it is a reversible device (that we can equalize it with the Carnot efficiency)?

Graphene is a wonder material with exotic properties. But, zero band gap in graphene hinders its application in logic devices. what are the factors responsible for bandgap opening in graphene? How band gap is opened by hetero atom doping and chemical modification in graphene

I want to find the equation for momentum of gases in thermodynamics. Please help me . I need it urgently. Thanks

Hi, I'm now facing problem on how to calculate the force, frequency and cycle needed for fatigue testing of a test sample. The force is refer to compression and tensile stress. Please kindly advice an solution regarding the above problem. thanks

Hello, Apologies for banging in a question on my first post, but I am at a loss with my research. I am a designer, and am looking at using a ceramic tube as a pressure vessel. This vessel will be pressurised to 5000psi (~340bar). I need to place this ceramic within another material that will contain it in the chance that the ceramic fails catastrophically. I cannot use metals as they are conductive. Originally I have looked at another ceramic tube lined with ptfe (teflon). This worked 2 in 3 times, I need something more fail safe however. Hoping someone can help, Ginge

I want to be able to calculate the force required by a hydraulic cylinder to lift a 3500kg load vertically to a height of 1.2 meters in a time of approximately 3-4 seconds. Can someone help. All comments will be hugely appreciated.

1. Why both L of left hand and right hand figures are different? 2. Why mg is put on the right end, not middle of the bar, in the right hand figure?

what is volume of liquid in partially filled cylinder. Asvolume= (Area of liquid)*(length of cylinder). I came across the following formula for volume of liquid incylinder but i can't understand it. the formula which i came across is: V= A*h = [(pi*R^2)/2- (R^3+R^2*h-3*R*h^2+h^3)/sqrt(2*R*h-h^2)] *L R= radius of cylindrical shell h= height of cylindrical shell L= length of cylindrical shell please tell me how it is derived and what it mean.

From what i've gathered their already patented and have more horsepower than the average combustion engine. Any thoughts on if this might take off or why it hasn't yet?

Hi there Everyone, I am new to this forum but certainly looking forward to some good conversation. Anyway really the question ive had on my mind for years now is "What speed do you need to travel to space at" Why I ask is that, this whole strap a big rocket to your bum and try and go as fast as you can model is good for a lot of things but BAD for most things. (Just imagine a house) Now if i was able to build a structure (the size and shape is not important) and strap a couple of small but adequate rocket engines to it, that would give me a terminal velocity of say 500mph, whats to stop me from just reaching this terminal velocity and then carrying on for li…

Hi, I have been looking about how to do a coil gun and did one with a coil of copper wire. But what would happen if instead a copper wire I use a entire copper cylinder drilling a hole side to side, so you have a air core coil (simple coil). I've read that the more dense is the coil, more power you will get. My question is, how would it effect the coil gun, would it not work because the resistance that gives the cylinder is so low that could make a short-circuit? Another question I have is, could you do an automatic coil gun at a speed of 100m/s? When I say automatic, I say like 60 rounds per second. Regards, Jonathan

The drones together transport a huge sheet of plastic or plywood in the middle of the hurricane, is it possible?

Situation: At the office we make disposable ovens. Temperature? Up to 500 F. Volume? It varies, but up to 60 ft^3. I say "disposable" because we use them to study the reaction of explosives to elevated temperature. Even under the best of circumstances, the ovens never get used twice. Oven construction is for the most part simple, but they are a pain in the arse to insulate. We have historically used fiberglass insulation like you'd put in your house, but it's itchy and difficult to control if the wind is blowing. We'd like something better. And so I wonder if anyone here has any words of wisdom.... Requirements: - Inexpensive. - Easy to w…

As I understand it when low pressure is at one end of a tunnel and high pressure at the other, air is blown down it. Is that right? If it is, then why isen't there wind turbines that operate in a tunnel, say starting at sea level and running up the side of a hill or mountain to create the pressure difference at either end? Surely then there would be a constant breeze to blow them and they would be more productive, unlike the ones I always see doing naff all.

Hi, my name is Ovidiu and are from Romania.De over three years working on an engine gravity , are about to make a functional model. Now gather parts layout. But I hit the indifference of others. do not speak good English, but for those who want more information, please contact me at email removed

Hello, I'm hoping someone here might be able to shed some light on a prehistoric engineering problem that I am struggling with: I'm working with the reconstruction of prehistoric iron smelting techniques. In short, what I do is build a clay furnace and fill it with various amounts of charcoal and iron ore while blowing air into it at the bottom. Coal and ore is transformed into solid iron that stays inside the furnace and liquid slag that runs out of the furnace. When the smelt is over, I pull out the iron and forge it into bars on a large rock. The furnaces are roughtly 30 cm in diameter and 70-100 cm high. One of the major problems is getting the furnace content…

Hello everybody! Several methods are used to control an aerostat's lift force: vary the ballast, leave gas escape, heat air, use propellers... Not always satisfactory, for instance if an airship isto transport cargo or serve as a crane. In 1982 I used a water solution of ammonia in a rigid bottle and a gas pump to extract ammonia from the solution in a separate envelope. That way, I could extract some volume without a big pressure change nor the associated power and energy need. But toxic, sure. Following here is a different idea - perhaps new, I didn't check. ==================================== I propose to control the aerostat's buoyancy through the…

This article got me wondering just how much of the manufacturing of computers ie laptops ,smartphones and tvs are done completly by machine/automation and how much would have to be left to be fully automated in each case. http://www.mnn.com/green-tech/resear...china-obsolete keep in mind the same premise i have stated in this topics beggining about a fuly automated moneyless society http://www.sciencefo...740#entry712740 http://www.ft.com/in...l#axzz2BvglZLwL http://www.wantchina...02&MainCatID=11 http://ifixit.org/2201/rare-look-inside-foxconn-reveals-more-automation-less-repairability/ okay i know the issue with regards to its harder to re…

hello everyone! i need help in iron ore pellet making. more specifically, promoting sufficient porosity in pellets. this is for my research, i need to know how porosity is formed during pelletization. can any1 help me with this. thanks loads.

If hyppothetically if one was to design a society wherein labor intensive work was performed by machinery in order to eliminate money(like star trek) and the need of humans in complex work could be eradicated to allow for the arrival of new incentives for humankind outside of the confines of monatary growth one must look at each sector of the economy in order elimate the need for scarcity and human labour.(in other words Star Trek) I know the agricultural industry can ruled out via hydro/aeroponics in the case of crops(as plants from the size of lettuce to cocoa trees and tea can be done at home or at the site of production.I also know algea can replace cotton,all for…

Hello dear friends! I'd like the cookers to reduce and adjust their power automatically when the liquid in the pan starts to boil, or the oil in the frying pan. Induction cookers, and some others, react quickly enough for it. Maybe they exist already? I suggested it to a Spanish company in 1996. I imagine the sensor could listen to the noise injected by the pan or frying pan in the cooker. Something like a wire could transmit the mechanical noise from the hot area to the vibration sensor working at cool temperature. Then, electronics could first filter the high frequencies or sharp transitions associated with bubbles, then either count the bubbles per time…

I recently purchased a toy for my son on Ebay that runs on salt water I guess it works on a chemical reaction with magnesium. Anyway the description was very broken english and I would like to know what this technology is called and any information you might deem relevant so I can find a "blurb" online in order to explain to him how and why it works and what else it is used for.