Engineering

Road reflectors, light posts, rebar, threaded rods and various screen tubing need to be anchored in concrete with epoxy. I'm trying to get an estimate of how many holes need to be drilled/mile of new road. Thanks!

Dear All I have a project to produce two injection-molded parts. One molded part was made of ABS. The other one was made of PP. These two parts contacted with each other. The ABS part rotated on the PP part (10 rpm). So, the ABS part abraded the PP part. After 500 times of rotation, the result was that the PP got serious wear. The rockwell hardness: ABS: R-Scale 110 PP : R-Scale 80 If I use an ABS material with Rockwell Hardness at R-scale 100, does the PP part get less wear? Thank you.

Hello everybody! In June 2015, the European Patent Office (EPO) awarded their European Inventor Award. Franz Amtmann and Philippe Maugars winned the "industrial" category for their contribution to the near-field communication (NFC) technology, and while the EPO's wording was still careful, in the Press it naturally became "they invented the NFC"... So here is my own compilation of some contributors I know of, where logically I'm not forgotten. ---------- Nikola Tesla made experiments and had big ambitions. He may have been the first (or not) as he had invented many more machines based on induction and RF. Though, the uses of electricity then, essentially f…

I know that traveling up a space elevator slows the earth slightly and traveling down it speeds it up slightly. I also know that this is a miniscule amount. I am curious though if this effect continues past the geosynchronous orbit point if the load were to continue on the cable towards the counter weight? Also would any type of engine exerting a force on any point of the elevator also change the speed of rotation or would it simply destroy the elevator?

I need some help intuiting the input vs output characteristic for the NMOS depletion load circuit. For example, I can see why the driver should start off saturated then move towards non-sat as Vinput increases, but I cannot see why the load should start off non-sat. Additionally, if we assume the output resistances to be large, then the driver switches to non-sat and the load switches to sat at the exact input voltage (which doesn't seem obvious to me). I have attached some figures to illustrate the problem.

Two related cases involving multiple coils around a cylindrical barrel. Two separate goals (but probably related math): Coils are activated in sequence to accelerate a magnetic object down the bore. Think 'Gauss-pistol'. Coils are activated (possibly with polarity reversal at/as needed) to smoothly accelerate a magnetic plunger down the bore -- and maybe cushion it when nearing the ends. When it reaches one end, the process is reversed to accelerate it back to the other end. Think 'rectilinear actuator'. Physical feedback (e.g., optical interruption) about the object's position in the bore is my first preference, since fancy harmonic circuits aren't my forte. I'm ba…

So I was wondering how many watts one can draw from a 12 volt dynamo and put into a battery. I would assume the speed of the wheel would influence the amps and then of course the volt times the amps would equal the watts. So I was wondering how fast(assuming there is not limit to human capacity) wold one have pedal to get the wheel moving and charge a 500 watt battery in 1 hour. I dont know if this matters but the wheel is 2 feet long

El Chapo civil engineering escape tunnel construction executed by gringos... The dissappearing act would had first been consulted to a magician consulting corporation, for several million $. The planning would had been three years since the first incarceration day. Tunnel construction permits to comply with city and county codes. The purchase of the property were to start digging would had been conducted by a registered realtor and obtained a normal 30 year mortgage to not be suspicious. A detour from the original planned path negotiated with GreenPeace to protect an endangered worm found there. The digging crews would had received legal overtime, morning and afte…

I have been looking for info on whether or not magnets could be used to push objects (repel) and be made small enough yet powerful enough to say move furniture, or even a car. The idea would be to attach a small metal tab (removable) under said object and roll a small device to lift and move with magnetic power with ease. Could that be adapted into a pinpoint repel to push things at a distance. Could be used for space travel or even deflecting some asteroids (mostly metal) Any research would be greatly appreciated and if this has been done please forward any reference.. tyvm.

Lately I have thought al lot about perpetual motion. I know that it's not possible, but what if you have a wind generator type machine. Instead of having it being powered by the wind, it has weights that extend out as they spin and retract as the reach the top of the machine. After a while it will lose momentum and slow down. I realize that that will happen but what if u made it so that the generator uses 10% of the power created to start the "perpetual" cycle over. Then it becomes endless. All the machine needs is a push to get it started and then it does the rest by itself. It's Infinite energy.

Hello I need help finding a university that I should apply for. I am going for a PHD in engineering if that even exists and I need answers for the best school of engineering that you know of so that I am sure what school to go to.

Figure, you have a heat source, heating up air in a pressurized chamber, with no outlet/exhaust...why doesn't it explode due to pressure build up of the heated gas? ~EE

is current density property of a material j⃗ (t,x⃗ )=ρ(t,x⃗ )v⃗ (t,x⃗ ). where ρ is charge density as a function of time and position and v is drift velocity of electrons as a function of time and position, in a conductor maintained at constant potential difference ?? is it that only having defined current density we can define current ??

I have been using mspaint to make figures, which proves tedious and leads to scruffy results. I need to make a couple very simple vector diagrams and simple graphs. Something that would easily allow me to re-create the attached file would be perfect.

i = dq/dt so for a conductor of length L, maintained at constant potential difference, we know that q = enAL where e is charge on electron n is electrons per unit vol. A is area of cross section of conductor SO in q = enAL what is changing with time so that we come across rate of change of charge

I've been reading up on piezoelectric materials; they're fascinating. I'm curious what the consensus is on the subject of using them in not merely creating artificial limbs for wounded war vets, but actually better protecting them from harm and enhancing their strength and endurance on the battlefield. War is exhausting, and tired soldiers make deadly mistakes. I'm guessing there would have to be a super-efficient on-board power supply. Several years back, I read some articles on super capacitors. As of my typing this, I've not read anything more on the subject, though I'll run a search after I post this. Anyhow, would those be suitable? (Pun!) And barring that, what …

Background: A few months ago I decided to start a small aquaponics (growing fish plus vegetables together) farm in the Philippines. I was hoping to make my production as efficient as possible. One way is to make the plant root temperature lower than 24 degrees celsius. I'd like to find the most cost effective solution to do this. Situation: A recirculating system with about 25,000 Liters of water needs to be cooled to around 24 degrees Celsius. A part of the water system is outdoors but still insulated by 2 inch styrofoam from direct sunlight. Typical ambient temperature during the day can reach up to 32 degrees celsius during summer. Water T…

I am trying to build a basic device using the copper and wire set up but I want to attach a handle which hooks up to the device. I am trying to build a type of engine. Now if the rod(Handle) is hooked up directly to the main source of energy(The Nail) than what material should I use to make you able to hold it? I was thinking of something that wont conduct the electricity or maybe covering it in something none conductive like Rubber. Any ideas? This is for personal use.. Not school project. I trying build something.

If you use the wirecopper on iron nail method will it create static or no? I was told that its impossible to get static from magnets this way. What would you do if you wanted small amounts of static?

Why they don't seal the turbines inside a vacuum? By watching this clip, https://www.youtube.com/watch?v=WTt_hoWtMIc, is clear that a wheel would spin much longer inside a vacuum. So, let's say that you use a normal wind turbine (or solar panels) to activate 10 other turbines sealed in a vacuum. It would be like multiplying the energy. What do you think?

I need to program a 4 wire stepper motor, problem is, there is no data sheet and no control circuit and i am completely lost. Can somebody please assist me with the ladder logic program to get it up and running? I have access to a decent PLC, and my only option is to hard code this, a control circuit is not an option.

Hello. Using a single internal combustion engine instead; what is a reasonable guess in needed power for this animal ? ----> http://www.gizmag.com/flike-personal-flight-manned-flying-bike/37779/ (Video at end of page)

Hi dear friends I work with sulfuric acid and 0.75HNO3+0.25HCL for a gold refining project. The main problem is the huge amount of those acid vapors in the place. Did any body have the same problem? Could we get and filtrate the acid vapor with the activated carbon? Any related help is really appreciated. Thanks all

Every chemical explosion produces a broadband electromagnetic (EM) pulse (EMP). A Los Alamos National Laboratory (LANL) report states, "The emission of electromagnetic radiation from a chemical explosion is well established." However, it is difficult to find reports that identify the intensities in the various spectral ranges. A Lawrence Livermore National Laboratories (LLNL) report states, "In the brief instant of a high-exlosive detonaton, some remarkable events take place: the shock wave produces pressure up to 500,000 times that of Earth's atmosphere, the detonation wave travels as fast as 10 kilometers per second, temperatures can sore to 5,500 kelvins, and power…

I would like some help understanding how to find the equivalent resistance of the circuit as shown in the included figure. I also want to clarify another thing; when finding the input resistance for the section, do we completely ignore the other side (RHS) of the circuit? The reason I ask this, is that normally I solve for Vx and Ix at the Req point and then Req = Vx/Ix; in this case it is not possible to solve for Vx without using the RHS of the circuit.