Engineering - March 2007

2007-03-19 15:53:27 · 6 answers · asked by steveo 1

2007-03-19 15:30:47 · 3 answers · asked by corey m 1

is the rubber is one of the materials can be used?

2007-03-19 15:30:17 · 1 answers · asked by natha 1

I'm flow testing a gas well, and the pressure keeps dropping while the rate is staying the same. What should I do? Should I keep testing? Increase the choke? Thanks in advance!

2007-03-19 15:28:05 · 1 answers · asked by oilpersonwoohoo 1

i have an idea for an invention where can i turn it in to??

2007-03-19 15:01:53 · 2 answers · asked by ? 2

Hey,

On an Electronics project I'm working on, I need to light and LED if at least two of the four inputs are at a logic 1. The boolean for this would be:

(A.B)+(A.C)+(A.D)+(B.C)+(B.D)+(C.D).

Obviously I can simplify this to:

(A.(B+C+D))+(B.(C+D))+(C.D)

But still, I'm using too many gates.. Is there any way to simplify this even more?

Or, as a bonus alternative, is there a chip that takes 4 inputs and gives a different output depending on how many inputs are at a logic 1?

I also need to do this for 3 LEDs, the boolean for which would be (A.B.C)+(A.B.D)+(A.C.D)+(B.C.D)

Which simplifies to (A.((B.C)+(B.D)+(C.D)))+(B.C.D)

-> (A.((B.(C+D))+(C.D)))+(B.C.D)

Which, again, takes too many gates.

So, simplification of the two boolean statements would be wonderful, or information of a [common] chip that takes 4 inputs and gives an output dependant on the number of inputs that are at a logic 1, please!

2007-03-19 15:00:23 · 1 answers · asked by Genki G 1

Given that a 2-stroke configuration increased power density two-fold over a 4-stroke configuration, why does it appear that efforts to develop a more fuel efficient 2-stroke engine are minimal, at best? 2-stroke engines utilizing valves rather than ports have been developed, but have never been commercialized. I'm trying to find out what are the primary obstacles/objections to developing such an engine - either gasoline or diesel.

2007-03-19 14:59:52 · 6 answers · asked by NEIP2000 1

For the output characteristic graph of a Bipolar Junction Transistor, common base configuration, why there is collector current flow when the Vcb(Collector-Base Voltage) is zero?

Also for the difference between the output characteristic graph of common base and common emitter, the saturation region.

Common base's saturation region happens when Vcb < 0 while common emitter's saturation region happens when 0< Vce(Collector-emitter voltage) < 0.7.
Any reason and explaination?

2007-03-19 14:47:44 · 1 answers · asked by AlexTan 3

Using the formula, and knowing that in parallel circuits there is more voltage coming in, compared to a series circuit, with a higher current than a series. In a series circuit the voltage is lower, but so is the current. This means that the resistance of both series and parallel circuits should be the same when using the same voltage bulb and battery.

2007-03-19 14:28:11 · 2 answers · asked by armenharoutunian 2

what are polymer nanocomposites, their properties, characteristics, applications and future applications..

2007-03-19 14:22:39 · 2 answers · asked by marky 1

For both a series and parallel circuit if i am using the same battery with a switch the resistance should be the same for both of them. Right?

2007-03-19 14:21:15 · 4 answers · asked by armenharoutunian 2

2007-03-19 13:58:51 · 5 answers · asked by Roberto L 1

if there is a potential difference of one volt and a current of one ampere this means that there is one ohm of resistance in the conductor or circuit.

2007-03-19 13:58:08 · 4 answers · asked by armenharoutunian 2

2007-03-19 13:50:34 · 3 answers · asked by armenharoutunian 2

2007-03-19 13:35:09 · 5 answers · asked by armenharoutunian 2

Using only two op-amps with the following specs:
1: Low Frequency Gain: 2e5 V/V
Unity Gain Frequency: 1.5 MHz
Slew Rate (Rload less than 1k ohms) = .7 V/us
2: LFG: 15e5 UGF: 8MHz SR(load less than .5k): 2.8 V/us

An amplifier must be built with a gain of 100 V/V, a max output voltage of 4 Vpp and a bandwidth of greater than 130 kHz

How would I go about starting to construct this....any pointers?

2007-03-19 13:29:44 · 3 answers · asked by Patrick M 2

what is extended huffman coding.How it can improve the performance of a system?

2007-03-19 12:48:20 · 1 answers · asked by Anonymous

I need to build a water rocket for my science class. I have already made the rocket, but am struggling to make a launcher. Our teacher wants us to build it, not our parents, so it needs to be fairly simple. I already purchased a bicycle inertube valve, which is used by alot of people. I also need to make the launcher tilted at a 60 degree angle for best distance, NOT greatest height. Please be descriptive when answering.

I need to know how the bicycle pump connects to the mouth of the 2 litter bottle.

2007-03-19 12:27:36 · 3 answers · asked by Ariel S 3

2007-03-19 12:19:51 · 4 answers · asked by texasfarmer 1

Weight of the whole world.

2007-03-19 11:49:23 · 5 answers · asked by Saumya T 1

I read somewhere that 2A -> voltage = 100volts, 473 = 47000pF or 47nF, K = +/- 10% Tolerance and J = +/- 5% Tolerance. Is this true? I'm not sure about the Voltage 2A if its really 100volts or 50volts and K & J Tolerance? Is there really a big difference with the tolerance K = +/- 10% and J = +/- 5%? especially if I use it in a sound producing device such as tone pots of a guitar? Are these polyester film or mylar? Hoping for your kind replies. Thanks in advance...

2007-03-19 11:42:55 · 2 answers · asked by James C 1

I already the know the common sense answer for this. A decrease in temperature difference between the inside of the house and outside of the house means the heat loss is less. Multiply the reduced heat loss by the amount of time the temperature is lower gives a daily (or hourly or whatever) energy savings. I have seen a rule of thumb that for every 1 deg C you drop the thermostat, you get a 2% savings (of course this is over that period of time).

Being an electrical engineer (not a mechanical engineer), I want to know what the calculations are for finding this out. Or a link to a site that explains it would be fine. I have already done an internet search, and came up empty after 30 minutes. There are plenty of sites that have built in calculators, but none that I can find that give you the formulas, and the reasoning behind the formulas. It would be nice to be able to input the insulation R value in the mix, as well as the efficiency of the furnace. Thanks!

2007-03-19 11:04:41 · 3 answers · asked by photoman 1

What field in Science and engineering would be closest to the design and construction to new snowboard, golf club technology? A title of a major and why this pertains to what I’m talking about. Thanks alot

2007-03-19 10:48:25 · 2 answers · asked by GHSballer@comcast.net 1

2007-03-19 10:22:55 · 2 answers · asked by deedee 1

If I have theoretical system where thermal noise is input to an amplifier which has a gain of 20dB and a noise figure of 3 dB, I should see a 3dB rise in the thermal noise, correct?

Conversely, if I have a system noise of say -125 dBc/Hz, I should see an increase in that system noise by 20dB, correct?

2007-03-19 10:18:57 · 2 answers · asked by Anonymous

I'm using electrolysis, but I'm trying to find a way to keep the cathode and anode from deteriorating without using an electrolyte, just pure water. Will putting the electrolysis on an AC current slow down the deterioration exponentionally if I can get the anode and cathode to hold a charge????

Please help, Inventor in distress!

2007-03-19 09:47:48 · 3 answers · asked by jpferrierjr 4

I never see any trucks come along to refill them or anything. It's wierd.

2007-03-19 09:47:02 · 3 answers · asked by elusive1151 1

2007-03-19 09:46:20 · 1 answers · asked by MiG 2

2007-03-19 09:36:37 · 6 answers · asked by MICHAEL J 1

2007-03-19 09:26:10 · 3 answers · asked by Anonymous