Engineering

How precise can a mobile phone operator locate a hand set position? What factors contribute to that precision? I was thinking if it is possible for a mobile phone operator to simply exclude a single building (or even large room inside a building) from the mobile-phone service? For example, would it be possible to arrange with mobile phone operators to exclude cinema halls or school classrooms from its service? I am aware that mobile phone operators would have no interest in doing so, but law can be adjusted so that they must comply (in some cases, at least)... Do you already know a mobile phone operator offering such posiblitiy?

Hi, the idea is to build a solar field in space, pretty close to the sun. i wonder if by increasing the intensity of light we can improve the amount of current produced. i have 3 questions: 1) does the amt of current generated from solar panels depend upon intensity of incident radiation? 2) Is it possible to convert electricity into a highly coherent beam (eg. electromagnetic wave or something alike) and transfer it through a great distance?? 3) is there a formula to calculate electrical output using intensity of sunlight or distance b/w source and panel??

How far do you think modern engineering and astrophysics are from constructing a fully operational Dyson Sphere, given economic issues, man power, limitation of modern day science?

Hi, does anybody have the book Hydraulic Machines: Turbines and Pumps by Grigori Krivchenko in a pdf?? I really need it.... Thanks a lot...

ramjet falls from a position, ramjet activates, ramjet returns to a position and then repeats. or what say the ramjet is pushed from b platform at a position, ramjet activates, ramjet is pushed back to a position / b platform. The scramjet will not hover, instead it will attempt to remain in a fixed altitude. It will do that by going up and down, if you imagine some sort of fixed unmovable object from when it is at pos a. When it falls from pos a it is now away from the unmovable object. Take the unmovable object and see it as the hover height.

No wind required, you start rotating them and they will never stop, energy problem solved, is it?

I'm not sure how viable this would be, but how effective would wind turbines be that are located along the side of busy highways and interstates? I came up with the idea after practically being blown off the road due to a semi-truck / 18 wheeler passing me on the interstate. It occured to me that vehicles, especially big rigs, generate a lot of wind as they travel down the highway at speeds of 70 - 80 mph. I am wondering if we could harness the wind using turbines that are located along the side of the highway, and if this could generate a significant amount of electricity? Any thoughts regarding this idea?

Hi, Does anybody knows any popural textbook about geothermal energy?? Something for starters on the field... Thanks a lot.

Hi all, Currently i'm have obtained results which shows that both longtiudinal and shear wave velocities increases after every round of fatigue test. Is there anyone can help me explain this phenomenon? is it due to the atomic structure in the material? if possible, plz give some websites or sources that can read more about them. thanks

I was thinking that it would be really cool to build a low(er than normal voltage) stun gun. The aim of doing so would be to produce an electrical shock which isnt serioulsly painful or more to the point harmful! Obviously, primarily i would need to reduce the current, however to help to do this I will need to decrease the voltage. This is easy as I can just use a smaller transformer. Here is a diagram: image dont work yet... go here (stun gun 2) nice and simple 9V battery -> 555 ICC -> transformer -> electrodes a few questions: 1) what transformer should i use? (asked because i dont really know what voltage i want... and be serious, i w…

Hello, May anybody tell me how to calculate allowable stress for brass tube if heat exchanger has to be designed per EN 13445-3? Table 6.1 Maximum allowed values of the nominal design stress for pressure parts other than bolts (EN 13445-3), gives only formulas for carbon and austenitic steel. I know how it can be solved per ASME, but how it can be determined per European code? An early reply would be appreciated. Thanks in advance.

hi, I need to design a gear system which uses the linear motion of a descending mass (20 kg) and convert it to rotary motion.The required output speed is 150 rpm. It would be of great help if someone could help me with the following.Thanks in advance. i.The technical specifications of the gears i can use in this case. ii.How can the mass (20 kg) be coupled with the gear system.

Dear Sir, I'm an undergraduate. I'm doing a project regarding Vehicle Exhaust Gas Analyser. Can I use following type of sensors to detect exhaust gas levels ? CO>> http://www.ebay.com/itm/DC-3-5V-MQ-9-Combustible-Gas-Carbon-Monoxide-CO-Sensor-Module-MQ9-Detector-/300847030943?pt=LH_DefaultDomain_0&hash=item460be1629f CO2>> http://www.ebay.com/itm/Carbon-dioxide-sensor-Gas-sensor-module-/170969527732?pt=LH_DefaultDomain_0&hash=item27ce93f5b4 HC>> http://www.ebay.com/itm/MQ-5-Gas-Sensor-module-for-Methane-Butane-and-Propane-Arduino-Compatible-/130711771878?pt=LH_DefaultDomain_0&hash=item1e6f075ae6 I must be thankful to you if u will rep…

Here is something that has held my interest for a while now. I was reading my thermodynamics textbook and there was a short article that mentions an experiment involving nanoparticles where the second law did not apply for up to two seconds. It then gave this citation [Phys. Rev.Lett. 89, 050601 (2002)] . If you would like read the topic more in detail here is a link to a description of their experiment http://www.aip.org/pnu/2002/split/598-1.html . I have asked my thermodynamics professor what he thought of it, but he didn't want to believe it. I asked my modern physics professor that does research in micoelectromechanical systems (MEMS) and he was not surprised. I am ju…

The purpose being to iluminate a north side wall of a house to decrease mold growth. - One single large convex mirror, or an array of many small convex mirrors (equal in mirror area) - Which choice will reflect more sunlight to the dark wall for a decent number of sunlight hours and angles daily ? Or is there a preferred shape as ellipsoidal for the task ?

How long before 4D printing and molecular assembler take of? Would you say 10 or 15 years out? What are they using 4D printing and molecular assembler now? I can't seem to get much information on this.The only thing I can find is this. http://allthingsd.com/20130226/from-ted-the-future-of-robots-4d-printing-personalization-and-adaptation/?refcat=news What would 4D printing be used for? Team of scientists in Toronto Canada are doing that now. http://www.torontosun.com/2013/02/28/4d-printing-lets-objects-build-themselves

How do I dissipate static electricity... From my treadmill? Note that the ground in my house is crap. It's an old home, and while it has grounded outlets on the wall, I'm fairly certain they are not grounded outside. When I'm running on my treadmill, static electricity builds up so when I grab the handles it shocks me... often, and frankly I'm sort of tired of it. I tried taking a metal clothes hanger and wrapped it around the leg of the handle and touched the other end of the clothes hanger to the floor, but that doesn't seem to be doing much for me. Is there anything else that would help? I'm wondering if maybe there is a device that can be clipped on to …

I am designing an experiment in which I will need to suspend a small amount of an alloy between a series of electromagnets. Is there an alloy that I could use that will be able to be suspended between electromagnets without actually touching them and will not hold any residual magnetism or at the most hold magnetism for a very short period of time? To be honest I'm not even sure if an electromagnet will magnetise metal like other types of magnets will. Any and all input is greatly appreciated. Thanks for your time.

First of all, i am young and not with much knowledge. I have a few questions for a project of mine, which i will start sooner... or later. Is it possible to transmit energy/electricity from far away? (Tesla had something similar) How else could we put something in space, other than rockets? (Elevator would need long cable... would be too heavy.What about Slingshot in a long pressurized tube? Using Magnets? ) The idea is to cheaply shoot something in space, by any one (close to sun for example) which could generate electricity by transmitting it back to earth. What other problems does this idea have? Sorry for my ignorance in advance.

I believe a limiting factor in developing higher efficiency engines is sticking since day one, to use water as coolant. My point is replacing water based coolant in ICE engines, -An oil cooled engine- with the most convenient transmission fluid. or diesel, or kerosene, or transformer oil, or refrigeration oil, or hydraulic fluid, or some other petroleum derivated, or a blend of the above -but no water content at all- Which can: - Eliminate boiling at 'normal' operating temperatures, - Eliminate rust progress or prevent it, - Eliminate pressurized circuits, - Eliminate freezing, no specialized orange, green, whatever coolant additives, - Incre…

first think of normal nucklear plant and how much it produces energy? then think of nuckealer submarine reactor and how much it produces ? and then this why dont they use in space stations/shutles nucklear energy reactor and build it inside a freezer so it cools down and if submarine nucklear reactor is efficient enough why dont use them to power up towns factories building them inside a freezer too

Hi, currently i'm having question regarding the internal stress distribution for circular and rectangular shape soild. May i ask why their internal stress distribution is different? Is it because the inner sturcture or composition of the soild is different? Or is it their calculation of stress is different? Please kindly advice Thanks

I am trying to coach kids in science olympiad and hate to disappointment them. I attached a file. I need to use to class of levers in conjunction to create an IMA of 5. Is the attached photo correct? Thanks for any help you can give.

Hi everyone! I'm new to this forum (this is my first post) and would like to ask for some help with a project that I have started (not sure if this is the right place to post this though). Overview: I want to make an autonomous robot that can move around by itself and detect and avoid obstacles (think iRobot or Roomba style). Reason for doing this: I am really interested in the field of robotics and thus want to get into it well. So I picked this project as it is very fun so I can not only make it but also learn from the experience, such as making circuits, coding, designing the actual robot, the mechanics and whatever else is required to make it tick. I am most…