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Was not to implement it, just to learn how it works. Thanks.

Thanks, gentlemen. The answers escape my level of comprehension; I will need to learn more about the basics to grab the concepts, and perhaps re-word the same question in the future. From what I understand, the energy to run continuosly a vacuum pump to evacuate the vapors in partial vacuum distilling plus the heat energy supplied is more than doing the same at 1ATM, no pump. Choosing partial vacuum distillation over atmospheric is not aimed to save some energy, but for other reasons as maintaining a lower temperature; of when the temperature of the heat resource is low. Then, to distill seawater, the 'energy price to pay' for the task is not decreased by the lower temperature-partial vacuum technique. Something left out is Takes 1K cal to raise 1 litre of water 1℃ at 1 ATM Takes 540K cal to evaporate 1 litre of water at 1 ATM ----> If the water is in partial vacuum, are the figures 1Kcal/Kg and 540Kcal/Kg still valid constants to use ? Thanks for the patience

Hi all. A litre of water at 25℃ needs a certain amount of calories to become steam at 100℃ ∆t=75℃ (75Kcal + 540Kcal =615Kcal) if I remember the figures. That is a 1 ATM. Under partial vacuum, such energy requierement can be less. Let's say it boils at 45℃ under such partial vacuum ; ∆t=20℃ thus would need 20 Kcal + 540Kcal = 560Kcal ---> Are the calories needed at 1 ATM and under partial vacuum constants ? The difference in energy needed to achieve the same are different under the different pressures. Some extra energy has to be used to run a vacuum pump. ---> Is the sum of energy to boil at 1ATM equal to boil under partial vacuum + the energy to run the vacuum pump ? In other words, does vacuum distilling uses less energy ? Sorry for my poor wording

Thanks. I expected to see the video, but could not pull it at the site: http://www.dw-world.de/dw/article/0,,4820233,00.html

Hello. Just saw announced/shown on television an experimental 'old' car running plastic scraps into a gasification reactor fitted in the engine compartment, yielding 30% less fuel consumption. The small device appeared to be about 1 litre size. How does it work ?

Inflate a balloon with air. Fill an identical balloon to the same exact volume with water Drop them simultaneously from your hands from exactly the same height. No need to climb on a building. They are both same size, same shape, same coheficient of friction. They have different masses. Check if they hit the floor at the same time

Interesting, you have not noticed it... How can a mosquito have the strenght/ability to grab onto something or have the instinct to prevent from being carried when soo many other more massive things are transported far away in a soo strong wind force. Is the only thing left to speculate, the mosquitoes after a hurricane were residing far away before the event ?

Is there any mosquitoes, flies, birds ? For how long ? Did most die or were just carried away ? (or new ones brought with the wind) If they persist, how does something like a dragonfly manages to stay put in the area ? Is it a major factor for dissemination of species across regions ?

Thanks again, Melvin. "the Al/Cu cell is that the amperage is very low" -->Isn't that more a function of the electrodes area? What am unhappy with Cu/Al is that would yield too low voltage. "if you used a more alkaline solution" -->No, the whole thing is about seawater. "you could be able to make a crude cell that could just be replenished with acid" -->Am not trying to make a cell on my workbench; it is more like trying to learn what voltage would yield dipping a 4'x8' Mg and a 4'x8' stainless steel plates in the real sea. Yes, that big. I cannot forecast results from the electromotive series and galvanic series tables, I even do not know why are they different nor which one to use and how.

Thanks, Melvin. The point is not the economics of the cell construction at all. The Mg-graphite on link above seems to be the most convenient and effective way to produce electricity (~1.5V) from seawater and am happy with it. These cells are used in open sea bouys that provide telemetry for years between servicing, at the expense of Mg metal as a 'fuel', and am happy with that. Cost of Mg is peanuts compared to moving a ship and crew 2000 miles for servicing shorter duration cells. My lack of understanding is the (chosen?) use of dissolved oxygen which is present in limited amounts on the electrolyte that has (apparently to me) much higher availability of Cl, Na ions to engineer a reaction. Let me put in other words. Using Mg; what other energic electrode instead of graphite coud interact with the ions instead of oxygen to produce long life electricity ? For sure developers of such cell had it very thought. I just do not get it. Another cell could be made with Al and Cu electrodes (none being pure sodium), but the generated potential is only ~0.3 V and does use Cl and Na ions for the reaction, not oxygen. So, could the voltage be raised to nearly 1 Volt and use the ions ?

Hello. I do not get it; can anyone explain on layman terms ? This reaction on a Mg - C cell uses the dissolved oxygen : http://www-odp.tamu.edu/publications/191_IR/chap_03/c3_5.htm From the galvanic series table Mg and C are at the extremes (I assume to yield maximum potential difference): http://www.corrosion-doctors.org/Definitions/galvanic-series.htm ---> Why are the most abundant Cl and Na ions not considered better to be used for the reaction ?

Do you really believe the police in such risky country can be alerted by the gadget ? Do you think the perpetrators will leave your technobra on you? Perhaps a different applicable strategy applies : http://www.wimp-software.co.uk/ http://forum.xda-developers.com/showthread.php?t=340667 http://www.luisespinosa.com/trackme_eng.html Miguel

Whaaaat ???

How does the device briefly shown here inside a cabinet works ? http://www.youtube.com/watch?v=V1IfzVrNqtU&feature=related The output seems to be a detergent injected with microbubbles. How does the mixing produces the bubbles so small ?

Found something, but still do not know what compounds are they Niopen http://www.alibaba.com/product/ua103664211-103455883-0/Foam_agents_for_foamed_concrete_making_NIOPEN_and_BIOPEN.html and OBSH http://www.alibaba.com/product-gs/237089510/OBSH_foaming_agent.html Miguel

Hi. My father once told me that in those days of early automobiles with fail-prone windshield wipers, applying a raw potato cut surface to the glass exterior forms a sheet of water allowing decent vision; was a common resource then, and it is confirmed to work well. What goes on and what chemical from the potato is the acting agent, and equivalent 'modern' chemicals? Miguel

Hello Paul. The wires can be made/insulated/routed to not short circuit. Or, if you prefer, insert a car cigarette lighter element at the end inside the handle. That will really put you cooking... Same safe low voltage (12V or less for less amount of heat) http://www.coolest-gadgets.com/20080716/heat-me-usb-heated-stirrer/ http://www.surplusandoutdoors.com/ishop/877/shopscr3059.html Miguel

Hi. Seen variations of your post in several places. Your whisker, http://virtue.win.mofcom.gov.cn/www/23%5Cvirtue%5Cimg%5C2008829174856.jpg with a metallic tubular handle could host a few automotive light bulbs inside. (there is some cylindrical ones that could well fit) http://www.autoguide.net/apf/images/products/engineparts/5y89947950lhi.jpg Solder the connections, bring the wires out at the end of the handle, and being powered by 12V, pose little risk of electrical shocks, will transmit their heat easily trough their glass to the handle; and the supply is not a hard thing to find (a spare laptop supply works) Then, the whisker can be held with an oven mitt. Miguel

Hello. Resistive wire is what you want; as the one in your bread toaster, the one that glows red. Wrapping the tubular handle with a heat conducting - electricity insulator material and a few turns of the wire will warm thing up. Such wire is also used in hair dryers, electric blankets... Depending if you want to warm up your hand or the stirrer, place some thermal insulation accordingly. Apply only the needed voltage to obtain the desired temperature depending on how long/thick is the wire. I do not think that wire is the proper one. Nichrome is preferred for your application. Miguel

Hello. Do you know of any inorganic compound in powder form that becomes gas when triggered by an 'stimulus' like light, microwaves, heat... Like every particle of the powder release or turn to gas ? I want to make bubbles, megazillions of them... How is styrofoam made? Is it by mixing two chemicals or by external stimulus ?

Hi. Itching is not a painful sensation, as pinching, or piercing, or a burn... Scratching provides relief, and pleasure. If some of you have had serious/intense skin complications; will understand scratching can get pleasant to extremes. What goes on with the causes of itching ? Not only related to insect bites, but the sporadic skin manifestation, either by a recognizable presence of a microbe or none. How come scratching provides pleasure? An 'evolutionary' thought of scratching providing dissemination of microorganisms under fingernails... is that real ? Let me say it different... Do itching causers provide chemical pleasure to bearers so scratching promotes dissemination ? Would an analysis of material under the fingernails show spores or something that proves scratching is a transmission method of itching causing microorganisms ? Sorry about my poor English Miguel

A 3 blade turbine, and a 12 blade turbine; being both the same diameter http://econewmexico.com/system/files/images/wind-turbine-wind-mill.jpg Which one is more efficient, can produce more power ? There has to be other variables as blade pitch, blades area, speed... even temperature... What formula applies to find out the power that can be extracted from a given wind speed ? Asking this because a large count blades turbine presents a larger blockage and reaction to wind than a 3 bladed one as the modern turbines are designed. There has too be other economical and construction factors involved to choose one or the other, but as amount of wind capture, one has clear advantage.

Thanks, Klaynos. It was more qualitative and behavioral than specific; but can put some simple generic figures if helps. A 10cm x 1cm x 1cm magnet bar suspended in space produces a 'small' amount of magnetic field at a point X distant 100cm perpendicular from its center. Its lines of force 'exit/enter' the ends of the bar magnet describing a certain undisturbed and smooth typical curvature. Its lines of force reach point X faintly being that much distant. What manipulation of the magnet / lines of force could increase the magnitude of the magnetic field at X. See the figure here: http://www.acesinternational.org/images/32NE0014.gif How 'smooth' the lines of force are sketched entering/exiting the ends of the magnet. See : http://www.bbc.co.uk/schools/ks3bitesize/science/images/sci_dia_75.gif how the lines of force are exiting/entering almost perpendicular to the magnet end because of the repulsive field nearby. Is that sharper bend yielding/projecting more lines of force at X ? It is basic that I express properly my question; please let me know if it needs more improvement. Miguel

Obviously, the post above has to be very poorly expressed and unclear to receive no responses. Am sorry. Allow me to ask from a totally different angle: What magnet shape would project its lines of force further away? A bar, a horseshoe, a plate, a cube, a slitted, a sphere, ...

A plain bar magnet --------------------------------------------------------------------------------- N................................................................................................S --------------------------------------------------------------------------------- above, will produce a given field at point x below : ................................................X If the ends of the magnet body are bifurcated by slits "===" : --------------------------------------------------------------------------------- N.................................................................................................S ===......................................................................................=== N.................................................................................................S ---------------------------------------------------------------------------------- Each end will have two same polar N-N , and S-S. That will make the lines of force at the ends, to diverge, by repulsion to each other. Will the same point X then experience a larger, equal or greater field ? ..................................................X In other words, will the magnetic field reach farther or be stronger by slitting the ends of a bar magnet? [ignore the dots on the sketch] Miguel