Jump to content


icarus

Member Since 13 Sep 2007
Offline Last Active Apr 28 2018 12:39 PM
*****

Posts I've Made

In Topic: Some photos of bits I made for bonfire night 2017

28 February 2018 - 09:09 PM

its time to buy shares in titanium flake producers ..They looked great!!!


In Topic: Munroe effect - practical demonstration

26 January 2018 - 06:23 AM

It does a good job of demonstrating the principle in a safe way and the loud bangs of the exploding hydrogen/oxygen  mixture  excite the young audiences  interest . I want them to see that science is interesting, challenging and exciting.  LIke many teaching aids from a theoretical view this method is flawed . The imprint produced is nothing more than block printing caused by the pressure wave pressing the leaf into the soft plasticene and is not due to the munroe effect .  I was taught by tutors and lecturers  whose explanation of what was happening was partially  bullshi*  .The Bohr model of the atom and water boiling at 100C with no mention of pressure volume temperature relationships or why the temp remained at 100C whilst it bolled .to name just 2 of many. 

 The most important thing was that it fed and sustained an interest in science, so now i carry on the bullshi* tradition excused by a noble motive! 

The paper i quoted from is interesting reading

Munroe demonstrated the shaped charge effect blasting a hole through a safe with a quantity of explosive that had  had no effect when placed as a blob against the safe .Althogh the effect carries his name he was not the originator .The original work was by german scientists Von Baader in 1792, Von Foersters in 1883 which lead to an american patent in 1886 by Gustav Bloems  The enhancement of the effect from vaporisation of a metal support cone was around 1933 and Germany was using shaped charges in many war-time weapons  from hand grenades through to mistel  a 2M diameter shaped charge nosecone containing 3500KG of explosive mounted onto a plane to be dropped onto the target .

 

Record what you see without bias Not what -you expected to see!  . When you come across an anomally try and repeat it. 

Dont believe everything you are told- it will limit your questioningof what you see 

 

I recently produced what I claimed was an enormous magnetron  built from 8 magnetrons with a large accompanying  power supply .I switched it on whilst it was surrounded by engineers you could hear the psu humming  I approached it with a large fluorescent tube in my hands this illuminated brightly "Cor  its chucking out so much microwave radiation I can feel my eyeballs heating up "  I exclaimed -seconds later the room was empty !! .  It was a great hoax the power supply had a battery operated buzzer in it  and the massive magnetron concealed a small tesla coil with a spike output whose reatively harmless high voltage field illuminated the fluorescent lamp i held      .For some strange reason I have not been invited back there??????


In Topic: Boric acid

12 January 2018 - 11:53 PM

that is really re assuring!! boric acid was also called boracic acid  the pure pharmaceutical version was sold by chemists shops in solution with an eye bath . it was a superb mildly antiseptic eye wash . i used it when due to lack of experience/ carelessness i got  arc eye  from careless welding . You only get it once !!- the day after welding agonising pain from recovering uv fried eyeballs. Boracic acid eye drops were the best for easing the pain and i am thankful to read that it  also killed any residual ants or cockroaches.  reprotoxic?-  no worries  at age 60+  !!! 

boric acid is very useful for production of green flames


In Topic: Drying stars

20 October 2017 - 10:00 PM

the only changes i would make is to remove the thermostat as it is capable of generating a spark as the heater element switches on and off .the slight danger comes from solvent based compositions developing a flammable vapour air mix within a sealed chamber which is fired by the spark . there is virtually no risk from the sealed element unless the fan failed . the fan motors are shaded pole motors so no sparking slip rings or commutator so the motors are good/safe . I would replace the thermostat by a st1000 digital thermostat these sit safely outside the drying chamber with a remote temperature sensor on a cable that is fitted into the chamber . you would then have a safe chamber  whose operating temperature can be very accurately set between room temp and about 85 C  . fantastic for yoghurt,   cheese culture, yeast starting etc. For ultimate safety i would also fit a clixon or thermal fuse rated at approx 150 C above the heater element to shut off power if the fan failed..              i can help with this if you wish . and will post full info if anyone needs help

.

The local surplus merchant had large cloth bags of Silica gel dessicant these have to be dryed in the oven at approx 120 C  before use   I have a modified fan in a vent pipe that blows air through the dessicant bags into a sealed chamber the exhaust air from the chamber goes through ducting to the fan forming a closed loop system with a digital humidity meter on the door. the chamber is a small dead fridge stripped of its mech using this i can dehdrate without temperature rise  but it works quicker at higher ambient temperatures . 

 

A third approach is to box in a small Peltier  dehumidifier into a drying box

 

I design and build replacements  and upgrades  for obselete or broken equipment 


In Topic: Ammonium perchlorate fountains

20 October 2017 - 09:23 PM

you are welcome to experiment in nwleics be good to see you again . we cannot store, so any composition must be burnt or deactivated on the day of experimental work. rocket motor /driver  and gerb research welcome ,