[Robotgroup] water flow

Def Egge robodigest at innervate.com
Fri Aug 11 07:16:09 PDT 2006 

Tinopal (Ciba-Geigy) is commonly used as are a variety of other
carboxylstilbenes and umbelliferones.

All should be commercially available from sources if willing to order
sufficient quantities.

When I get some free time, I will do some searching of the uspto.gov site
and see what formulations have been patented.


All the best....

Mike




At 20:29 2006/08/10 -0500, you wrote:
>Mike,
>
>Any idea what makes fabric softener fluoresce? It seems like this  
>would be a lot less of an irritant since people wear clothes covered  
>with it all the time. I have no idea how bright it is compared to  
>other purpose-made chemicals, but it looked pretty good on that one  
>episode of a little TV show called Lost where the CIA spook drew a  
>map of the island on the back of a blast door. Probably no one has  
>ever heard of this show before though ;  )
>
>Les
>
>
>On 10 Aug 2006, at 3:44 PM, Def Egge wrote:
>
>> Of course, oil and water do not mix so well but, perhaps, that is  
>> all right.
>>
>> Polyethylene oxide dissolved in low concentrations can drastically  
>> alter
>> the viscosity of water.  Glycerine, methyl cellulose, sugars, low  
>> molecular
>> weight alcohols, etc. are cheap, easily-obtained water-soluble  
>> substances
>> that might be worth experimenting with.
>>
>> Fluorescein, mentioned in an earlier post, though fairly non-tocix,  
>> is a
>> major irritant to skin, eyes, and mucus membranes.  It might be  
>> wise to
>> avoid triggering allergic / asthmatic reactions among onlookers.   
>> [I seem
>> to remember that the fluorescein-containing lasers created respiratory
>> problems when they leaked in a lab I used to hang out in.]
>>
>> All the best....
>>
>>
>> Mike
>>
>>
>>
>> At 14:58 2006/08/10 -0500, you wrote:
>>> If we are talking about making water look pretty, perhaps you  
>>> could add
>>> some other fluid to the water to change its properties (viscosity or
>>> whatever).  Oil comes to mind as a possibility.
>>>
>>>
>>>
>>> Leslie Filip wrote:
>>>> Did you use angled blades that were in sync with the speed of flow?
>>>> If this is not taken into account then the result sucks. FYI I am
>>>> talking about blobs that are around a half inch in diameter, not
>>>> sprinkle. I think a frozen arc of blobs is magnitudes more
>>>> interesting than a single vertical stack of droplets, granted even
>>>> those are pretty cool looking with the fluorescent dye and UV LEDs.
>>>>
>>>> I keep saying this so please if someone has seen otherwise correct
>>>> me: "The start of laminar flow requires a ramp-up of speed within  
>>>> the
>>>> output chamber before exit." This is why trying to pulse blobs  
>>>> with a
>>>> plain valve does not work. It is the uniform speed and trajectory of
>>>> water molecules in laminar flow as well as surface tension that
>>>> allows the blobs to remain coherent.
>>>>
>>>> Looking forward to the party.
>>>>
>>>> Les
>>>>
>>>>
>>>> On 10 Aug 2006, at 12:47 PM, brooksdesign wrote:
>>>>
>>>>
>>>>> I tried several chopping type methods but none worked as good a my
>>>>> sprayer hose valve thing in the sink .I have been messing with
>>>>> chamber with water feeding in the side ,a nozzle on top and a
>>>>> diaphram on bottom that can be pulsed by mechanical piston on a
>>>>> crankshaft of with air pressure .I discovered this while rinsing
>>>>> out a soap bottle ,good blobbieness .I'm building this as part of
>>>>> the stage show I'm planning for the .....wait for it ....The last
>>>>> party and official house dissassembly event at brooks' place in
>>>>> Bastrop (no date yet but soon).
>>>>> -brooks
>>>>>
>>>>> -----Original Message-----
>>>>>
>>>>>> From: Leslie Filip <lfilip at mac.com>
>>>>>> Sent: Aug 10, 2006 7:29 AM
>>>>>> To: Austin Robotgroup Mailing List <robotgroup at puremagic.com>
>>>>>> Subject: Re: [Robotgroup] water flow
>>>>>>
>>>>>> If the blades are in a blower-type arrangement instead of a fan- 
>>>>>> like
>>>>>> arrangement it would chop the water more smoothly. The nozzle  
>>>>>> would
>>>>>> have to be shooting from within the cage though.
>>>>>>
>>>>>> Les
>>>>>>
>>>>>>
>>>>>> On 10 Aug 2006, at 2:53 AM, Leslie Filip wrote:
>>>>>>
>>>>>>
>>>>>>> Gray,
>>>>>>>
>>>>>>> I believe it is still laminar flow you are wanting, only that
>>>>>>> instead
>>>>>>> of constant streams you want blobs. In order to accomplish  
>>>>>>> this the
>>>>>>> material has to have a ramp up of speed inside the laminar  
>>>>>>> flow tube
>>>>>>> before it exits. In the examples I have seen, it was not  
>>>>>>> possible to
>>>>>>> have a series of closely spaced blobs using only control valves.
>>>>>>> There may be a solution.
>>>>>>>
>>>>>>> If you have an arc of laminar flow water, I believe you could
>>>>>>> mechanically chop it into blobs, removing the water where you  
>>>>>>> want
>>>>>>> space. Think of the way a jet engine's blades are tilted. As the
>>>>>>> water passed through rotating blades the entry point and exit  
>>>>>>> point
>>>>>>> of the blades in the water column would coincide with the forward
>>>>>>> motion of the water arc, thus chopping it into a series of small
>>>>>>> cylinders. Then through surface tension, each cylinder would  
>>>>>>> reshape
>>>>>>> itself into blobs. It is the lack of uncontrolled angular  
>>>>>>> momentum
>>>>>>> that allows the blob to remain a blob.
>>>>>>>
>>>>>>> There is a limit to the speed at which the water can travel as a
>>>>>>> blob, however. When the speed goes beyond a certain point, the  
>>>>>>> air
>>>>>>> pressure at the front of the blob destabilizes it. In a parabolic
>>>>>>> arc, this is as true for the speed at which the water exits the
>>>>>>> nozzle as it is for the descent.
>>>>>>>
>>>>>>> The arcs I saw in Las Vegas in some of the smaller water gardens
>>>>>>> went
>>>>>>> about 10-12 feet without a problem. The arcs are more prone to
>>>>>>> destabilization than blobs due to surface tension and the  
>>>>>>> differing
>>>>>>> speed from one part of the column to another. I don't think there
>>>>>>> would be any problem at all with blobs remaining blobs over this
>>>>>>> distance.
>>>>>>>
>>>>>>> Les
>>>>>>>
>>>>>>>
>>>>>>> On 09 Aug 2006, at 5:26 PM, Gray Mack wrote:
>>>>>>>
>>>>>>>
>>>>>>>> What I am looking for is a term for creating liquid
>>>>>>>> blobs. How big they can be and stuff based on driping
>>>>>>>> from a drop tower or launched.
>>>>>>>>
>>>>>>>> Another approach- Put some LED's, a microcontroller, a
>>>>>>>> capacitor, and an inductor+rectifier into a bunch of
>>>>>>>> ping pong balls. Fire them from an air blower/cannon
>>>>>>>> at synchronized intervals in an arch or straight down
>>>>>>>> or through a clear pipe and when they land they roll
>>>>>>>> to a hopper to be recycled. As they are loaded into
>>>>>>>> the cannon the capacitor is charged through the
>>>>>>>> inductor via a varying magnetic field at the cannon
>>>>>>>> and instructions on when to light up are also sent
>>>>>>>> through the field to each ball. The capacitor has
>>>>>>>> enough power to blink LEDs a few times during its
>>>>>>>> travel as directed by the cannon.
>>>>>>>> -Gray
>>>>>>>>
>>>>>>>> --- Shane Geiger <sgeiger at ncee.net> wrote:
>>>>>>>>
>>>>>>>>
>>>>>>>>> FYI:  http://en.wikipedia.org/wiki/Laminar_flow
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> Paul Atkinson wrote:
>>>>>>>>>
>>>>>>>>>> Gray,
>>>>>>>>>>
>>>>>>>>>>   I don't think you'll have a problem if you
>>>>>>>>>>
>>>>>>>>> aren't susceptible to jitter between pulses (as
>>>>>>>>> stepper motors are.)
>>>>>>>>>
>>>>>>>>>>   You may have to have a special driver (giveio)
>>>>>>>>>>
>>>>>>>>> or something like that to access the parallel port
>>>>>>>>> under Win XP/NT/2k if memory serves.
>>>>>>>>>
>>>>>>>>>>   The opposite of laminar flow is turbulent flow.
>>>>>>>>>>
>>>>>>>>>>   Paul
>>>>>>>>>>
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>>>
>>> -- 
>>> Shane Geiger
>>> IT Director
>>> National Council on Economic Education
>>> sgeiger at ncee.net  |  402-438-8958  |  http://www.ncee.net
>>>
>>> Leading the Campaign for Economic and Financial Literacy
>>>
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