Comments for Joss Research Institute http://jossresearch.org Sat, 05 May 2012 16:51:28 +0000 hourly 1 http://wordpress.org/?v=3.3.1 Comment on Joss Research Institute Web Report #7 by Jon Singer http://jossresearch.org/2011/02/13/joss-research-institute-web-report-7/#comment-1311 Jon Singer Sat, 05 May 2012 16:51:28 +0000 http://localhost:8888/jossresearch/?p=52#comment-1311 This is excellent -- _many_ thanks, both for responding and for the information! (I will look for the Peter Bowers book.) It is my pleasure to be able to help with the photos. I could make myself worry about the difference between 6m and 6.6m (a full 10%), but it probably isn't worth being concerned about. The important thing is that Platz came up with a very viable design; the specifics are likely to be somewhat fungible. That said, if/when I get back to this project I may have to look around for a bit of wind-tunnel access... Best -- jon This is excellent — _many_ thanks, both for responding and for the information! (I will look for the Peter Bowers book.)

It is my pleasure to be able to help with the photos.

I could make myself worry about the difference between 6m and 6.6m (a full 10%), but it probably isn’t worth being concerned about. The important thing is that Platz came up with a very viable design; the specifics are likely to be somewhat fungible. That said, if/when I get back to this project I may have to look around for a bit of wind-tunnel access…

Best –
jon

]]> Comment on Joss Research Institute Web Report #7 by Joseph Hutchinson http://jossresearch.org/2011/02/13/joss-research-institute-web-report-7/#comment-1308 Joseph Hutchinson Sat, 05 May 2012 08:53:55 +0000 http://localhost:8888/jossresearch/?p=52#comment-1308 2nd note: the glider page you link to has a photo of an article. I can just make out that the Wingspan is "6.60 meters". I estimated from 3/4 view in my book that the glider is ~6m span x 4m long. Looks like we're in the ballpark! 2nd note: the glider page you link to has a photo of an article. I can just make out that the Wingspan is “6.60 meters”. I estimated from 3/4 view in my book that the glider is ~6m span x 4m long. Looks like we’re in the ballpark!

]]> Comment on Joss Research Institute Web Report #7 by Joseph Hutchinson http://jossresearch.org/2011/02/13/joss-research-institute-web-report-7/#comment-1307 Joseph Hutchinson Sat, 05 May 2012 08:37:38 +0000 http://localhost:8888/jossresearch/?p=52#comment-1307 I've just found your excellent detailed article of the Platz Sailboat Glider after 2 hours web surfing the subject. I saw the craft originally a dozen years ago in "Unconventional Aircraft" (P. 6-7) by Peter Bowers, 1984. Have been considering a model of it ever since, but had to estimate dimensions from a 3/4 view. The other views are really a help visualizing and I very much appreciate your work sussing the details. The other really helpful article was a July 1940 Pop Sci (P. 26) reprint of one from 1924 which was sourced from one in a German mag ZFM (Zeitschift fur Flugtech und Motorluftshifffart) January 26, 1924. Your pics are much better, however. Also See: www.johndobson.info/George/pdfs/Chapter%2015.fm.pdf http://www.sil.si.edu/smithsoniancontributions/AnnalsofFlight/pdf_hi/SAOF-0001.1.pdf http://www.youtube.com/watch?v=YlGrDwjjm7o (just posted!!) I hope you will add your pics and data to the Wikipedia article on Platz. It's woefully short for such an important designer. Thanks! -JH I’ve just found your excellent detailed article of the Platz Sailboat Glider after 2 hours web surfing the subject. I saw the craft originally a dozen years ago in “Unconventional Aircraft” (P. 6-7) by Peter Bowers, 1984. Have been considering a model of it ever since, but had to estimate dimensions from a 3/4 view. The other views are really a help visualizing and I very much appreciate your work sussing the details.

The other really helpful article was a July 1940 Pop Sci (P. 26) reprint of one from 1924 which was sourced from one in a German mag ZFM (Zeitschift fur Flugtech und Motorluftshifffart) January 26, 1924. Your pics are much better, however.

Also See:
http://www.johndobson.info/George/pdfs/Chapter%2015.fm.pdf
http://www.sil.si.edu/smithsoniancontributions/AnnalsofFlight/pdf_hi/SAOF-0001.1.pdf
http://www.youtube.com/watch?v=YlGrDwjjm7o (just posted!!)

I hope you will add your pics and data to the Wikipedia article on Platz. It’s woefully short for such an important designer. Thanks! -JH

]]> Comment on Joss Research Institute Web Report #10: Laser Dyes for the DIYer by Jon Singer http://jossresearch.org/2011/03/18/joss-research-institute-web-report-10-laser-dyes-for-the-diyer/#comment-1114 Jon Singer Thu, 29 Mar 2012 06:28:57 +0000 http://localhost:8888/jossresearch/?p=55#comment-1114 Hi. I have only used fluorescent highlighters; I have never made one, so I have no idea what you should use for an ink formulation. Wish I could help you, but I just don't have the information you need. Best -- jon Hi.

I have only used fluorescent highlighters; I have never made one,
so I have no idea what you should use for an ink formulation.

Wish I could help you, but I just don’t have the information you need.

Best –
jon

]]> Comment on Joss Research Institute Web Report #10: Laser Dyes for the DIYer by ashish http://jossresearch.org/2011/03/18/joss-research-institute-web-report-10-laser-dyes-for-the-diyer/#comment-1099 ashish Sat, 24 Mar 2012 08:54:39 +0000 http://localhost:8888/jossresearch/?p=55#comment-1099 hi! i am ashish.i require your help. i want to make fluorescent highlighter.i have dye. what should be the formulation of ink? which products shall i add in to the dye? if you know,kindly reply me. HAVE A NICE DAY! hi!
i am ashish.i require your help.
i want to make fluorescent highlighter.i have dye.
what should be the formulation of ink?
which products shall i add in to the dye?
if you know,kindly reply me.
HAVE A NICE DAY!

]]> Comment on Pumping a CW Dye Laser with a Green DPSSL Module by Christopher Townsley http://jossresearch.org/2011/08/31/pumping-a-cw-dye-laser-with-a-green-dpssl-module/#comment-954 Christopher Townsley Mon, 27 Feb 2012 23:26:47 +0000 http://96.127.149.74/~jossrese/?p=130#comment-954 Hi, Have you got any further with this? Regards, Christopher Hi,

Have you got any further with this?

Regards,

Christopher

]]> Comment on Joss Research Institute Web Report #16: DIY Hollow-Cathode Lasers by Colin S. Willett http://jossresearch.org/2011/02/13/joss-research-institute-web-report-16-diy-hollow-cathode-lasers/#comment-238 Colin S. Willett Mon, 21 Nov 2011 15:25:13 +0000 http://localhost:8888/jossresearch/?p=67#comment-238 Dear Jonsinger, You might care to read "Introduction to Gas Lasers - Population inversion Mechanisms' by Colin S. Willett. This is a book published by Pergamon Press and was based on my thesis for my PhD in 1967 for the University of London. Though I was not able to obtain laser action in any of the number of hollow cathode discharge devices (HCD's) that I built in the period 1963 through 1967, I have written evidence to show that I was the first to suggest HCD's could be used for producing metal vapor in which laser action could be produced from energy-transfer from inert gases employed as discharge buffer gases. I referred to HCD's as producing metal vapor from "spluttering" rather than the correct term "sputtering!" The idea of using HCD's as sources for metal lasers occurred while I was doing a project on HCD's at the Northampton College of Advanced Technology (CAT), London, England for a Dip. Tech. in Applied Physics that was awarded in 1963. This was after attending an evening presentation by Oliver S. Heavens on lasers. In 1963 I joined Professor Heavens at Royal Holloway College who was then a Reader in Physics of the University of London to work on lasers. Dear Jonsinger,

You might care to read “Introduction to Gas Lasers – Population inversion Mechanisms’ by Colin S. Willett. This is a book published by Pergamon Press and was based on my thesis for my PhD in 1967 for the University of London.
Though I was not able to obtain laser action in any of the number of hollow cathode discharge devices (HCD’s) that I built in the period 1963 through 1967, I have written evidence to show that I was the first to suggest HCD’s could be used for producing metal vapor in which laser action could be produced from energy-transfer from inert gases employed as discharge buffer gases. I referred to HCD’s as producing metal vapor from “spluttering” rather than the correct term “sputtering!” The idea of using HCD’s as sources for metal lasers occurred while I was doing a project on HCD’s at the Northampton College of Advanced Technology (CAT), London, England for a Dip. Tech. in Applied Physics that was awarded in 1963. This was after attending an evening presentation by Oliver S. Heavens on lasers. In 1963 I joined Professor Heavens at Royal Holloway College who was then a Reader in Physics of the University of London to work on lasers.

]]> Comment on Along The Red Temmoku Trail by jonsinger http://jossresearch.org/2011/02/13/along-the-red-temmoku-trail/#comment-173 jonsinger Fri, 11 Nov 2011 05:13:23 +0000 http://localhost:8888/jossresearch/?p=8#comment-173 Hi. Hope dinner ended up being okay. (I'm extremely pleased that you like the "stuff". Here's a short video in which I assemble a nitrogen laser and run it; from parts on the table to laser light, about 3 minutes; overall duration 4:52. Huge file though, because I didn't compress it -- more than 40 MB. http://71.166.254.214/pictures/video/TEA-n2-laser_show-and-tell.mov [If you have any trouble with that, please email me.]) Best -- jon Hi.

Hope dinner ended up being okay. (I’m extremely pleased that you like the “stuff”. Here’s a short video in which I assemble a nitrogen laser and run it; from parts on the table to laser light, about 3 minutes; overall duration 4:52. Huge file though, because I didn’t compress it — more than 40 MB. http://71.166.254.214/pictures/video/TEA-n2-laser_show-and-tell.mov [If you have any trouble with that, please email me.])

Best –
jon

]]> Comment on Joss Research Institute Web Report #21: Room-Pressure Nitrogen Lasers by jonsinger http://jossresearch.org/2011/04/28/joss-research-institute-web-report-21-room-pressure-nitrogen-lasers/#comment-172 jonsinger Fri, 11 Nov 2011 05:10:46 +0000 http://localhost:8888/jossresearch/?p=74#comment-172 I usually use a commercial energy meter head to find the pulse energy. With low-pressure nitrogen lasers, I use a Motorola MRD500 avalanche photodiode to visualize the pulse on an oscilloscope; but with TEA lasers, this is not so easy. I do not currently have a good way of "seeing" the pulse shape, so ordinarily I assume that it is more or less a half-sine with a short tail, and I assume that it has FWHM duration of about 800 psec. If such a pulse has energy of about 1 mJ, it probably has peak power of roughly 1.25 to 1.5 MW. One thing that seems to be crucial for clean discharge and good output, by the way, is preionization. If there is insufficient preionization, it is very difficult to get a spark-free discharge. If you allow the preionizer to take too much of the electrical energy, however, it interferes with the laser. There is a delicate balance between these extremes, and I am currently thinking about the edge profile of my preionizers. Hope this is helpful; I am happy to talk more about it. Best -- jon I usually use a commercial energy meter head to find the pulse energy. With low-pressure nitrogen lasers, I use a Motorola MRD500 avalanche photodiode to visualize the pulse on an oscilloscope; but with TEA lasers, this is not so easy. I do not currently have a good way of “seeing” the pulse shape, so ordinarily I assume that it is more or less a half-sine with a short tail, and I assume that it has FWHM duration of about 800 psec. If such a pulse has energy of about 1 mJ, it probably has peak power of roughly 1.25 to 1.5 MW.

One thing that seems to be crucial for clean discharge and good output, by the way, is preionization. If there is insufficient preionization, it is very difficult to get a spark-free discharge. If you allow the preionizer to take too much of the electrical energy, however, it interferes with the laser. There is a delicate balance between these extremes, and I am currently thinking about the edge profile of my preionizers.

Hope this is helpful; I am happy to talk more about it.

Best –
jon

]]> Comment on Joss Research Institute Web Report #21: Room-Pressure Nitrogen Lasers by davod http://jossresearch.org/2011/04/28/joss-research-institute-web-report-21-room-pressure-nitrogen-lasers/#comment-123 davod Tue, 25 Oct 2011 19:18:08 +0000 http://localhost:8888/jossresearch/?p=74#comment-123 please tell me, what do we calculate the power density or energy of each pulse of transvers excited nitrogen laser? may laser have poor output, like your laser. please tell me, what do we calculate the power density or energy of each pulse of transvers excited nitrogen laser?
may laser have poor output, like your laser.

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