Engineering - February 2007

http://www.wired.com/news/technology/0,72703-0.html?tw=wn_technology_1

2007-02-13 09:33:48 · 5 answers · asked by yahoohoo 6

i know people are using ultrasound but why is that? why not using RF 2.45GHZ with higher freq?

2007-02-13 09:15:32 · 3 answers · asked by Tom 1

I live in a shared house, with a gas powered central heating system, timed to come on at certain times every day. There are radiators in every room. An interesting debate arose recently:

If one person chooses to leave their window open (and their door closed] during the winter months, with their radiator on full, does this make the central heating system work 'harder', to heat the outside air, or does it not affect the amount of energy used? Does it make the rest of the house colder, because that radiator is on full while others may only be on half? Or does it just affect the temperature in that one room?

This is assuming that the overall boiler settings are not adjusted at all.

Many thanks for any help.

Mike

2007-02-13 09:02:48 · 9 answers · asked by MikeF 1

2007-02-13 08:55:17 · 6 answers · asked by Sore [Love Me If You Dare] 5

The gravity field and a mass within has an interaction. Since in every interaction there is a force - counter force effect there must be a force against the inertial force which "pushes back" the gravity field. I have a simple machine which makes spinning around two inertia axis at the same time and it eliminates energy constantly. But where do this energy go? Could it be radiated into the gravity field? I have not succeeded measuring any deflection in the gravity field (yet).

2007-02-13 08:06:03 · 5 answers · asked by Miklós G 1

i know that the frequency is different and the following

Ultrasound is narrow pulses
rf carries location data
ultrasonic signals reflects heavily
ultrasonic signals are pulses

2007-02-13 08:01:39 · 6 answers · asked by Tom 1

2007-02-13 07:50:06 · 2 answers · asked by mg 1

I am looking for a non destructive test method to check adhesion (or lack of) between 2 polymers. I was told Ultrasound and CT scan work. However, ultrasound requires something (in liquid form) to form the coupling, which will destroy my sample. I didn't even know we can use CT scan for things other than bodies. Does anyone know anything about this? I know for medical work, a person has to have contrast agent for CT scan to work.... again, it we have to put anything on my sample it will not work. Any other ideas?

2007-02-13 07:47:15 · 3 answers · asked by Ann H 1

2007-02-13 07:24:47 · 1 answers · asked by goring 6

I have a voltmeter, can it be used to measure the conductivity of an aqueous solution? Is there some circuit to attach it to? How is such a thing calibrated?

2007-02-13 07:14:11 · 7 answers · asked by b_bankhead 2

I'm trying to develop an inexpensive solar cooler for camping.

I've made a solar box COOKER before, using nested cardboard boxes painted black, with aluminum foil glued on the inside. The black surface absorbs heat from the sun's rays, while when the heat is re-emitted inside, the reflective foil tends to keep it in. It is a slow cooker which can develop about 325 degrees F.

Now I am thinking about trying the same idea inverted. I know I won't be able to freeze things. but if I start with something frozen, could I keep it frozen this way without having to use those pre-frozen plastic containers of blue chemical?

Anybody ever make a cooler like this? anybody know how? Any sites for plans? (not the cooker sites, I already have those.)

Please include ideas for evaporative cooling using wet towels, if that has worked for you in the past. I'm trying to do this no-electricity, no chemicals, no bottle of gas. I want to travel light.

Thanks!

2007-02-13 07:09:09 · 3 answers · asked by cdf-rom 7

Hi, Is there anyone with corrosion consulting experience that could help me? I need someone with a strong background in corrosion or marine corrosion to help me with a project I am working on. I am working on a website that deals with corrosion and could really use someone to help make sure all the informatin is correct. Please!

2007-02-13 06:50:56 · 2 answers · asked by CassieA 2

I'm trying to find some data comparisons between straw-bale and traditional structures. Namely cost and STC for walls. For example, excluding the cost and sound transmission of the foundation and ceiling, how would a straw-bale and stucco room compare to a wood frame/drywall or a concrete room in terms of cost per sq ft and STC.
Much thanks,

2007-02-13 06:40:36 · 3 answers · asked by alan p 1

Just wondering...
Why does US not follow metric system?

2007-02-13 06:21:26 · 25 answers · asked by Anonymous

2007-02-13 06:16:38 · 3 answers · asked by jonielittle 1

2007-02-13 05:08:52 · 4 answers · asked by findout 1

I work with an engineer who thinks it's 1940. Previous companies I've worked at allowed solid models to define parts with only the critical or inspection dimensions required on the paper drawing. He wants every single dimension on the paper drawing, but that takes much longer, plus is less acurate because changes to the model don't always correctly update on the drawing. Does anyone have a book or magazine article showing that solid models are acceptable for part definition? Thanks in advance.

2007-02-13 05:07:01 · 3 answers · asked by billy b 3

2007-02-13 04:39:28 · 3 answers · asked by RAZOR 1

A power unit is there by the bank of the river of 900 mtr width. a cable is made from power unit to power a plant opposite to that of the river and 3000 mtr away from the power unit. The cost of the cable bellows water Rs5 / mtr and cost of cable on the bank is Rs 4/ mtr. Find the pt where the cable cut through the river.
1.2800
2. 3000
3. 2100
4.3900

pls say the approach of solving the problem

2007-02-13 04:39:15 · 2 answers · asked by Anonymous

i.e. as if the building is growing out of the cliff

2007-02-13 04:24:50 · 5 answers · asked by Anonymous

2007-02-13 04:15:00 · 4 answers · asked by Anonymous

what is a easy bridge to build with wood and cardboard?

2007-02-13 03:29:53 · 1 answers · asked by Anonymous

All i know about PSI is that it has something to do with air pressure and that the internal prressure of a normal tyre is 32 to 34 PSI. But what exactly is PSI? Can anybody explain..?

2007-02-13 03:28:50 · 3 answers · asked by Anonymous

2007-02-13 02:52:23 · 2 answers · asked by seanclibbens 1

I'm buying 93.88 acres and about 1 of them is useable. The rest is mountain. The property is a big rectangle where the land forms a V. One side is a BIG mountain with protruding rocks and mature trees - we're talking dynamite to move. I won't touch that side as long as I own the property, it's too beautiful to mess with. The other side is more like a big hill - definitely some big rock formations that will prove challenging, but not as steep or rocky as the first side.

In the middle of the V is a stretch of creek with the side with the hill being the useable acre. I want to level the hill, or at least slope it at an easy enough grade for dogs and horses. My property basically divides at the top of it, but my history with the owners of the adjoining makes me think they will go halfway in this to move their half.

Where do I start?
I'm sure there has to be someone who comes out and surveys the property to give me an idea. What's his title and where do I find "him"?

2007-02-13 02:42:30 · 1 answers · asked by Amanda E 1

Is it possible to create a large hollow structure then vacuum all the air out so that it displaces enough atmospheric air to float? For example a giant glass sphere weighing 1E5 kg that displaces 1.5E5 kg of air. The only limitation I can think of is unless it's so large that it extends beyond our atmosphere.

2007-02-13 02:35:59 · 5 answers · asked by AaronX 2

2007-02-13 01:54:26 · 1 answers · asked by Steve B 1

2007-02-13 01:53:42 · 2 answers · asked by ramachandran n 1

2007-02-13 01:49:42 · 1 answers · asked by goring 6

They include glass, paper, aluminium, asphalt, iron, textiles and plastics. Biodegradable waste, such as food waste or garden waste, is also recyclable.

2007-02-13 01:44:34 · 1 answers · asked by Eric Inri 6