Engineering

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.

Hello. Why are in general, water pumps outlet made smaller diameter than their inlet ? This is not asking why inlets are larger; but you can also elaborate on that if you want.

Hi, Does someone know how to derivate the formula of White-Colebrook? The professor said this will probably be a question on the exam, but I have no idea how to do it... I've searched on the internet for quite a while and I can't find the derivation . This is the formula: I would really appreciate any help!

Many of you have probably seen the news about the new Tesla Power Wall, which is basically a lithium-ion battery that's meant to be recharged with solar power (or other renewable source) and keeps you from using any electricity from the grid at all. For those who haven't seen the news, you can watch the presentation by Elon Musk, who is admittedly a great entrepreneur, but in my opinion might need to work a bit on his presentation skills. What do you reckon, is it worth getting one? I've been thinking of one and it seems barely worth it because: - average daily electricity consumption for our house is ~8 kWh (averaged over the last 4 months) - solar panels on the…

The last time I studied radio electronics we were still using tubes (valves for you Brits), though the ideas of amplitude modulation and frequency modulation remain the same. Moving to the crux of the matter, is it possible to transmit a radio signal that is simultaneously amplitude and frequency modulated?

Slider & Crank Mechanisms. How would you obtain power and efficiency from a slider & crank mechanism. Is there a relationship?

I remember Mr. Clarkson made a mention of this in Top Gear a couple seasons back, but anyway - how do you get out of a car with gull-wing doors if it's rolled over and ended on its roof? I haven't found information about it, but I can't really imagine that engineers have disregarded such a glaring safety hazard.

Hello, I am planning on building an electrostatic ion accelerator by having a tube with parallel plate capacitors to have a negatively charge plate facing one direction and an electrode to generate the ions for repulsion. now my question is if I have the wire from the negative side of my high voltage source split so as to branch between the capacitor and the electrode would this decrease the voltage to either source? and my second question is what are ways to increase the charge density created by the corona from the electrode aside from just increasing the voltage into the electrode.

Hello everybody, I'm looking for an electromechanical relay capable of high switching rate (make and break) up to 100 Hz. Relay is supposed to be for 24 V DC circuit and of small curent rating (100-200 mA). I know such a high switching rate is difficult demand for electromechanical relays, and manufacturers I contacted told me they don't have anything above 20 Hz. However, I researched myself and found in the book "Electromechanical systems in Microtechnology and Mechanotronics" the following table: Therefore, the relays I'm looking for certainly exist, but I don't know where they are used . Anybody here know something about such relays and where I can get the…

I was having discussion with my friend yesterday, and he says the jet fuel from the jet that crashed into the towers cannot melt steel...which I fully agreed with him. However, I argued (and I'm no engineer by any means) that the impact of the plane, the weight, and heat combined made the towers collapse. A 168 ton plane, flying at 400 mph, had to have severlely weakened the immediate area that the aircraft impacted. Also, the steel beams were not engineered to hold a 168 ton aircraft, along with the high temperatures inside the tower. All these factors combined lead me to believe this is what caused the first or few floors to buckle causing the towers to fall…

I am going to attempt to make my own circuit using a printed circuit board I was looking for soldering irons on-line and they have it classified as such -heavy duty soldering iron -medium duty soldering iron -light duty soldering iron and also they have different wattages which i do not understand its benefit or disadvantages (30w, 120w etc)