Engineering

The riots in Hamburg Germany, for the G20, shows an army of riot police in very heavy clothing, helmets, and facemasks. It is also a hot summer day. The news made no mention of cooling systems inside the clothing of the riot police. How expensive would it be to wear a cooling system?

Why use highly complex rocketry and satellite guidance? If a terrorist wanted to get the job done...well you get the picture. I would think if this were somewhat feasible, it would have happened somewhere or at least been thought of. So my question...is it possible? ~ee

Since we are on the topic of grenades I thought up of a grenade with 360 degree cameras and a gun which when thrown into an enemy trench would randomly pick a path through the trench until it runs out of bullets or batteries. Would this work?

Why does this never get invented? The problem is car cabins can get VERY hot when parked under the sun. The temperature inside a car can get so high it will kill any babies or pets accidentally left inside the car. Even an adult will die inside a closed car in the hot sun, if they are unconscious or disabled. Also, it is very uncomfortable to start a very hot car. All it takes is intake fans in the floor of the car and exhaust fans in the ceiling, and the fans are powered by solar cells on the roof of the car. This would ensure that it could never get hotter inside the car than it is UNDER the car, in the shade, (because that is where the air intake is). Nobody …

Some time ago I saw articles, most probably from car manufacturers, describing the ideas/wishes of some, to use hydrogen as fuel for their internal combustion engines, if the economies turn to it as energy source and thus satisfy the environmental requirements. In my opinion it's not only the environment that has to be protected it's an economical matter too. Internal combustion engines can't get away of an overall efficiency in the low thirties while fuel cells climb to 80%. Huge difference. We understand how admirably the engine manufacturers have perfected them during the past 100 years or so, but they have to do the same with fuel cells and a lot faster,…

warning..this post is going to have some serious ignorance attached to it so I get that the chronology is vacuum tubes > transistors > IC's.... I remember seeing an illustration of a vacuum tube. It had a battery/ power supply connected to the VT. The VT conducted electricity and then sent signals throughout the computer. Why even have the power source (wall outlet basically) connected to the VT, and just hook up the power source up to the computer directly, with little logic gates to get it work send 1's and 0's? ~ee

Hi. Trying to find if there is in the market a mechanism that holds a string under pulling force by pinching and releases it by a solenoid or lever. Or an off the shelf device/gadget that can be re-purposed. String wound ------------------------pinching mechanism------------------------>20 Newton pulling force in a bobbin ^release solenoid^ Have you seen such in everyday items ? Sort of clothesline extender, window blind or something alike... Just trying to reuse instead of re-invent/design. If possible plastic, or non-corroding. Not self-rewinding as a measuring tape.

Hello everybody I'm from Iran and I have an urgent question, I want to find username &password of scientific University such as New York University and McGill and the other famous universities. Pleeeeease help me about finding MD accounts, If you don't have any information about my question, please introduced some forums or sites that they are selling or sharing these accounts... Thank you

It's a rather dumb question, but here it is: My thought of the major factor in efficiency between the two turbines is the amount of variation of temperature within the engine itself. *Does this hold true?* Here's my theory: The more consistent the temperature, the higher the efficiency. Gas turbine: Combustion of gases would have a slightly more temperature fluctuation due to occurrence of incomplete combustion of gases. Steam turbine: External source of heat constantly maintains gases' kinetic energy, keeping the heat consistent. Also water has a higher specific heat. Therefore, the steam turbine would theoretically be mo…

Global Positioning systems are extremely accurate typically <10m, assuming there is good satellite coverage. Satellites have both high and low orbit, Inmarsat coverage is particularly poor. I would like to start a discussion ref the reliability and accuracy of the various GPS networks. I am particularly interested in how the accuracy, or time, of the clocks may be affected if they are in different orbits around the planet, or at different altitudes or orbiting in different directions. For example if in orbit around the equator, at higher latitudes or perhaps orbiting over the poles. The reason the question occurs to me is that I use GPS in navigation off sh…

Might seem like a simple question but when I thought about it, I think how the wheels of the train stay on track needs to be elaborated. Sure, if the train travels only in one track, it has a steep extrusion at the middle of the wheel which allow it to stay in track, but... If it crosses another railway, how can we make sure it stays in track? Go here if you don't know what I mean: https://farm3.staticflickr.com/2513/3874671000_349f1f4b18_z.jpg?zz=1 http://static.panoramio.com/photos/large/58668679.jpg

Hello! What material would be best for condensating steam back to water outside? *To clarify, I am making something which involves turning jets of steam back into water outdoors in the blazing sun (Texas, baby!) and I need a cost-efficient material which I can shoot the steam against and have it condensate quickly back into water.

Please help me find the advantages and disadvantages of flying carinvention to our daily life

Hello, can you suggest me some good project ideas for a civil engineering student?

I have recently discovered that air is not just ionized by nature, but also by electromagnetic radiation. I have two questions: 1) how much electromagnetic power is needed in order to ionize the air (in terms of kw) 2) Does ionized air cause any adverse health effects when the ionization is caused by electromagnetic forces, rather than nature? Thank you

It's almost spooky what a robot will do with just a few simple rules, as with a PID controller. In my project below, at 1:20, all I do is issue a forward-command, and the system moves backward momentarily to tilt the robot forward, and then it moves.

Hi, Any advice on what the best type of heating solution would be for the following scenario? I have seen some large infra red patio heaters and have also looked at some gas panels. I am not sure if the IR will kick out enough heat for what we require. We need a heating panel (can be gas, electric, whatever) that is large and will kick out enough heat so that something left near it will start to singe. Ideally the item (a wood panel) will reach a surface temp of around 400C and stay about there. I remember the old electric bar heaters that were hot enough to set stuff alight if you left things too close.. (my nan's dog regularly ignited its fur by lying too cl…

I am a bit baffled why the Stirling Engine is not more commonly used when we, as a global community, need to turn out engines which are quiet and clean with a lack of heavy pollutants? What are the restrictions stopping the use of this beautiful engine? Link http://upload.wikimedia.org/wikipedia/commons/c/cc/Alpha_Stirling.gif

I didn't calculate anything till now, I don't know if radiation pressure is good enough to propel a spacecraft(My question). Obviously I'm talking about radiation pressure coming from radioactive dregs of nuclear fission! How it works? It's sufficient to release radiation in the space to have a propulsion in the opposite direction: it's conservation of quantity of motion because radiation pressure is a palpable quantity of motion!

Hi all. New to the forums but wanted to share a project I've been working on for a while. Since highschool I've been messing around fusors and other plasma based devices. I recently made a video going over some of the basics of working with these kinds of systems using mostly salvaged parts. Hope you enjoy

gif of girl with amputated hands using bionic hand: https://gfycat.com/VacantRequiredAmethystinepython How does the bionic hand know/recognize nerve signals being sent to the area that would be her hand? Also, how is it calibrated that it provides the right amount of tension with the nerve signal? ~EE

Hello to everyone , i spend 1 year in observing the whole idea an i solved it . my Question is do you think it is worth it to send the blueprints to some university ?

Photographic filter holders are usually metal. Looking for a source of plastic ones, to avoid corrosion. Need is to hold diaphragms instead of optical filters. Can be from any application other than cameras. Sample pictures ----> https://www.aliexpress.com/item/NEW-Camera-Filter-40-5-43-46-49-52-55-58-62-67-72-77-82mm/32655570830.html?ws_ab_test=searchweb0_0,searchweb201602_4_10152_10065_10151_10068_10130_10084_10083_10080_10082_10081_10110_10178_10136_10137_10111_10060_10138_10112_10113_10062_10114_10156_10056_10055_10054_10059_10099_10078_10079_10103_10073_10102_10096_10070_10148_10123_10147_10052_10053_10124_10142_10107_10050_10143_10051,searchweb201603_1,af…

I'm just asking when I woke up in the morning I just remembered a YouTube video about time traveling,a thing or a machine that is faster the the light can cause up time-warping(or time-travel). So a brilliant Idea just come out on my mind to make a sketch plan for a machine that can run fast in a miles but it not possible as well. A bullet train in Japan can run as fast as a sportscar but I need an idea for this (time-travel). In YouTube I just randomly found an interesting video that America has has a secret plan for making a time machine BUT I DON'T BELIEVE AS SOOO. So my point is what machine that can run fast

An oven using electric heating elements creates zones that widely differ in temperature, depending on proximity to the red hot heating element. Some modern units with a fan for circulation of hot air inside, should be considerably better. Microwave ovens deflect radiation into all directions with rotary motion. Can some type of moving 'mirrors' be implemented to incandescent heating elements to spread the radiated heat evenly without air currents ?