HDTenEightyP/NetNews huggingface dataset:
From: doug@netcom.com (Doug Merritt)
Newsgroups: sci.fractals
Subject: Re: Integrating over fractals
Date: 29 Sep 92 18:05:01 GMT
Organization: Netcom - Online Communication Services  (408 241-9760 guest)

In article <19scdaINNjrv@function.mps.ohio-state.edu> edgar@function.mps.ohio-state.edu (Gerald Edgar) writes:
>In article <1992Sep23.211017.11363@cs.brown.edu> jab@cs.brown.edu (James M. Borger) writes:
>>Does anyone know how to integrate functions over fractal sets using, of course,
>>the appropriate measure?
>
>The natural measure on the attractor of an IFS is found in Hutchinson,
>Indiana J. 30 (1981).  More detail is in Lalley, Indiana J. 37 (1988).

But of course there are other types of fractals. And I wonder whether
these references on some "natural" measure are sufficient to make it
obvious how to proceed with integration.

I had an idle thought relating to this recently. Many measures of interesting
fractal sets yield 0 (consider Cantor dust). I wonder if anything interesting
might turn up if one analysed it instead in terms of measure that allows
a result of a nonstandard analysis infinitesimal. Two different sets, both
with traditional measure zero, might well have different infinitesimal measure.

Since it has been proven that standard analysis can prove any result
about standard objects that is provable with nonstandard analysis, the
above could also be undertaken with the usual epsilon-delta methods,
of course. Pondering relative rates of convergence to zero has a different
flavor but amounts to the same thing. On the other hand thinking in
terms of infinitesimals often suggests different lines of approach...
	Doug
-- 
Doug Merritt	Preferred: doug@netcom.com   (or: doug@eris.berkeley.edu)
Professional Wild-eyed Visionary	Member, Crusaders for a Better Tomorrow
Newsgroups: sci.fractals
From: pisherwo@wm.estec.esa.nl (Phil Isherwood)
Subject: Fractal software for SUN
Reply-To: pisherwo@wm.estec.esa.nl
Organization: ESA/Estec/WMS, Noordwijk, The Netherlands
Date: Wed, 30 Sep 1992 17:32:55 GMT

Could anybody tell me where I can find some fractal generation software for a SUN SPARC station?
E-mail answers preferred.

Thanks in advance,

Phil Isherwood.



Newsgroups: sci.fractals
From: darrin@engin.umich.edu (Darrin P Cardani)
Subject: Re: Mac shareware fractals program?
Date: Mon, 28 Sep 92 22:44:37 EDT
Organization: University of Michigan Engineering, Ann Arbor

Try Mandelzot by Dave Platt. It seems to be the definative fractal
program for the Mac and has the best interface I've found for any fractal
program for the Mac. It's also quite expandable. It can be anon. ftped from
sumex-aim.stanford.edu
						Darrin Cardani
darrin@engin.umich.edu
Newsgroups: sci.fractals
Subject: Re: Animating Julias
From: <GE0QC@CUNYVM.BITNET>
Date: Wednesday, 30 Sep 1992 19:29:32 EDT
Organization: City University of New York/ University Computer Center

Cool!

Levi
ge0qc@cunyvm
Newsgroups: sci.fractals
From: ddixon@nyx.cs.du.edu (David Dixon)
Subject: Reference on Computing Multifractal Spectrum
Organization: Nyx, Public Access Unix @ U. of Denver Math/CS dept.
Date: Mon, 5 Oct 92 21:14:41 GMT

I need a good reference on how to compute the multifractal spectrum.  Thanks.

					Dave

DIXON@UCRPH0.UCR.EDU
From: keven@csugrad.cs.vt.edu (Keven Ring)
Newsgroups: sci.fractals
Subject: Fractal Posters
Date: 2 Oct 92 02:35:34 GMT
Organization: Virginia Tech Computer Science Dept, Blacksburg, VA

This was posted on alt.fractals in response to someone looking for some,
and it was advised to me to post it here as well.

I have a fractal poster.  I received it for X-Mas, but the company name is 
Art Matrix.  I also have two shirts by them.  No catalogue.  Here's their
address and phone:

  Art Matrix
  P.O. box 880
  Ithaca, New York  14851
  
  1-800-PAX-DUTY   or (607)277-0959 

and the poster was made by:

  Casisco Mathematics
  Burlington, North Carolina  27217

Hope that this is of help!
-- 
+-----------------------+"Frank-n-furter, it's all o-ver
|Keven Ring		|your mission is a failure. Your lifesyle's too extreme
|keven@csugrad.cs.vt.edu|I'm your new commander - You are now my prisoner
|VPI & SU		|We return to Transylvania.
From: eugene@wilbur.nas.nasa.gov (Eugene N. Miya)
Subject: 10/6 8 PM Mitchell Waldthrop Printer's Inc. PA
Organization: NAS, NASA Ames Research Center, Moffett Field, CA
Date: Tue, 6 Oct 92 22:19:22 GMT
Distribution: ba

Mitchell Waldthrop is at Printer's Inc. PA this evening at 8 PM.
(sp)	was the Editor of Science (the AAAS publication).  He is speaking
about non-linearly and chaos this evening.

--eugene miya, NASA Ames Research Center, eugene@orville.nas.nasa.gov
  Associate Editor, Software and Publication Reviews
  Scientific Programming
  {uunet,mailrus,other gateways}!ames!eugene
Seeking Books to buy:	Bongard, Pattern Recognition
			Imhof, Cartographic Relief Presentation
			Books on or by Benjamin Whorf
			Wulf et al, The Design of an Optimizing Compiler
From: mancini@fysik.uu.se (Derrick C. Mancini)
Newsgroups: sci.materials
Subject: Re: Uses of Be
Followup-To: sci.materials
Date: 5 Oct 1992 14:53:45 GMT
Organization: Fysikum, Uppsala Universitet
Distribution: world
NNTP-Posting-Host: usx215.fysik.uu.se

In article <009618DA.1AFE29C0@vms.csd.mu.edu>, 5916rahmank@vms.csd.mu.edu
(K. M. A. Rahman) wrote:
> 
> |>
> |>>	I also heard that it's highly toxic. 
> |>
> |>Some compounds are.
> |>

Actually, the dust (and hence its oxide) is extremely hazardous.  Exposure
to
Be dust leads to berylliosis.  But while the dust is toxic, the bulk metal
is
relatively safe to handle.  Any process that might lead to dust, like
machining
or corrosion, must be avoided.

> |>>What are the spectacular properties?
> |>
> |>Very light weight, very strong, transparent to X-rays down to very low
> |>energies, good neutron moderator, excellent heat conductor, as an oxide, 
> |>a very good electrical insulator while being a very good thermal 
> |>conductor.  Be is the lightest metal with any structural use.
> |>

Yes.  I have used Be for x-ray filters, x-ray windows, and ultra-light
optical
substrate.  Also, it is important as an alloying element.  And
copper-beryllium
oxide is used as the active surface in electron multipliers. 
Copper-beryllium
metal alloy is used as a spring material for ultra-high vacuum
applications.

Derrick C. Mancini
Fysiska Institutionen  -  Uppsala Universitet
Box 530  S751 21  Uppsala  Sverige
mancini@fysik.uu.se
---------------------------------------------
"Are we having fun yet?"  -  Zippy
From: jbbg0390@uxa.cso.uiuc.edu (God of Dichloromethane )
Newsgroups: sci.materials
Subject: Response to Optical pyrometry for MBE
Summary: Effectively cleaning substrates
Date: 28 Sep 92 18:20:34 GMT
Organization: University of Illinois at Urbana




It happens to be that my field of research at the University of Illinois is
directly related to the cleaning of substrate materials to enhance metal
bonding to plastics (mainly polymer matrix composites).  I'm not sure if I am
understanding the full scope of the problem; however, I know that several
chemicals are used to clean metal substrates.  Most metals prove to be very 
reactive with Chromic Acids and/or Chromic-Sulfuric acid combinations, therefore you may want to try those chemicals.


Justin
(i may not fully have understood the problem, but if not I still may be able to help).

l
Newsgroups: sci.materials
Subject: Uses of Be
From: dhayward@mtroyal.ab.ca
Date: 2 Oct 92 11:39:21 MDT
Organization: Mount Royal College, Calgary, Alberta

For years I have been interested in the present and future uses of
Berrylium. Due to it's many spectacular properties it should be more
common than it is. any info?
From: 5916rahmank@vms.csd.mu.edu (K. M. A. Rahman)
Newsgroups: sci.materials
Subject: Re: Uses of Be
Date: 3 Oct 1992 02:24:45 GMT
Organization: Marquette University - Computer Services
Reply-To: 5916rahmank@vms.csd.mu.edu
NNTP-Posting-Host: vmsd.csd.mu.edu

In article <1992Oct2.113921.2739@mtroyal.ab.ca>, dhayward@mtroyal.ab.ca writes:
|>For years I have been interested in the present and future uses of
|>Berrylium. Due to it's many spectacular properties it should be more
|>common than it is. any info?

	Be is used in nuclear reactors, I think in shut down process.
	I also heard that it's highly toxic. What are the spectacular
	properties?
	-Anis.
From: rrobinso@jade.tufts.edu (Rick D. Robinson)
Newsgroups: sci.materials
Subject: Materials Research Centers?
Date: 30 Sep 92 20:08:00 GMT
Organization: Tufts University - Medford, MA
Originator: rrobinso@jade.tufts.edu

Help 
I need to located the following Centers:

Ingal International Gallium
  GmbH
  Schnandorf, Germany

Thermophysical Properties Research Center
  Purdue University
  West Lafayette Indiana

I need some way to contact these labs hopefully through email.
Thanks in advance!
Please send replys to 
 
rrobinso@jade.tufts.edu

Rich
Newsgroups: sci.materials
From: WEBER@JEDI.SSD.LMSC.LOCKHEED.COM (Kevin Weber)
Subject: Re: Uses of Be
Followup-To: sci.materials
Organization: 78-30
Date: Mon, 5 Oct 92 15:37:15 GMT

In article <1992Oct2.113921.2739@mtroyal.ab.ca>, dhayward@mtroyal.ab.ca
wrote:
> 
> For years I have been interested in the present and future uses of
> Berrylium. Due to it's many spectacular properties it should be more
> common than it is. any info?

Be, as you know, has an excellent strength to weight ratio and specific
stiffness. At room temperature Be is 7 times stiffer than any other common
metal. It is used in the aerospace industry for mirrors, in some solar
panel applications, mounts which require exacting stiffness such as for
sensors and telescopes, and structural members requiring very high specific
stiffness. It's main drawback has been it's ductility, or lack thereof. It
is not used in fracture critical applications, unless it's properties
cannot be beat, such as some of the applications listed above.

New Be alloys are being developed with aluminum as a main alloying
ingedient in an effort to increase it's ductility. Some of the newer alloys
have ductilities up to 8 percent, which is comparable to some aluminum
alloys.

In general, I believe Be to be one of the most useful and underated metals
there is. It's hazardous nature is overated, although it is a bit
expensive.

The problem nowadays with the use of Be is it's undeserved reputation. With
greater environmental and safety concerns, people don't want anything to do
with Be.  As mentioned, it's fracture sensitivity has caused NASA to
virtually prohibit it's use unless absolutely necessary.  Strides are being
made to improve it's already outstanding properties, and I expect it's use
will increase in the future.

kevin weber  weber@jedi.ssd.lmsc.lockheed.com
Newsgroups: sci.materials
From: jdell@trl.OZ.AU (John Dell - Photonics)
Subject: Optical pyrometry for MBE 
Followup-To: sci.materials 
Keywords: Pyrometry, MBE, III-Vs, Temperature
Organization: Telecom Research Labs, Australia 
Date: Mon, 28 Sep 1992 07:16:22 GMT

Some one must have done this - low substrate temperature measurment for MBE.

We have a much modified (and now very old) Varian 360 MBE which we use for
growth of InGaAs/GaAs layers (MQWs for modulators and 980 nm lasers).
Currently we measure the substrate temperature in two ways -

1) We have a thermocouple attached to a sapphire bead which is supposed
to be in contact with the back of the Mo block (we still indium solder
our wafers but put silicon nitride or dioxide on the back which overcomes
a lot of the problems).  In practice, the sapphire bead doesn't touch the
back and we rely on radiative coupling to the bead (which isn't too bad at
high temps).

2) We have an optical pyrometer which looks at the side of the Mo block
but which has limited temperature response and depends critically on
what the condition of the Mo block is (ie coated with As, shinny, ...)
and how accurately you can point the pyrometer.

The system is calibrated using the Al/Si eutectic temperature.  We have
looked at using the oxide desorption temperature but seem to have a problem
with our substrate cleaning so that the desorption temperature appears
to vary by about 50 C from run to run.  (Anyone willing to tell me 
EXACTLY what their favourite cleaning recipe is?? - I've seen lots of
very brief descriptions but no real details.  We currently use a sulphuric
acid / hydrogen peroxide etch.)

Anyway, the problem (at last) is that we need to measure lowish temperatures
now (of the order of 300-500 C) and we would like some recommendations of how
to do this using optical pyrometry.  What have been peoples' experiences, how
do you calibrate the system, what products are available, how accurate
are they, how precise are they, do you look at the block or the semiconductor,
have you had to worry about the window (ie do you need a sapphire window
or will a standard window do and simply change the effective emissivity), 
do you need to heat the window to prevent condensation of As, how do you
limit the field of view .....? 

I hope someone somewhere can shed some light on the problem.  By the way, I'm 
sick an tired of trying to fix the sapphire bead thermocouple so as to
guarantee contact so please don't suggest that as a fix - unless you know how
to do it :-)

-- 
John Dell,Telecom Res Labs, PO Box 249, Clayton,  Victoria, 3168,  AUSTRALIA
Internet: j.dell@trl.oz.au				TEL: (+613) 253 6623 
UUCP:	  {uunet,hplabs,ukc}!munnari!trl.oz.au!j.dell	FAX: (+613) 253 6665
Newsgroups: sci.materials
From: trb8x@faraday.clas.Virginia.EDU (Thomas R. Burkholder)
Subject: Nickel plating (electroless)
Organization: University of Virginia
Distribution: usa
Date: Mon, 28 Sep 1992 21:39:04 GMT

Thanks to all who responded.  I also appreciated the fax.  Tom
--
*********************************************************************
****************         GOING TO CONNECTICUT         ***************
**************** Central Connecticut State University ***************
*********************************************************************
From: uno@sasaki.kuee.kyoto-u.ac.jp (Kazuyuki Uno)
Newsgroups: sci.materials
Subject: Re: Optical pyrometry for MBE
Date: 3 Oct 92 17:53:28 GMT
Followup-To: sci.materials
Organization: Dept. Electronic. Eng., Kyoto Univ., Kyoto, Japan.
In-reply-to: jdell@trl.OZ.AU's message of 28 Sep 92 07:16:22 GMT


    Hellow, I am a student in Japan.   And I use ANELVA S830 MBE
system.

>   Some one must have done this - low substrate temperature measurment for MBE.
>
>   We have a much modified (and now very old) Varian 360 MBE which we use for
>   growth of InGaAs/GaAs layers (MQWs for modulators and 980 nm lasers).
>   Currently we measure the substrate temperature in two ways -

I think you grow InGaAs/GaAs at Tsub=450 degree C or so.

>   1) We have a thermocouple attached to a sapphire bead which is supposed
>   to be in contact with the back of the Mo block (we still indium solder
>   our wafers but put silicon nitride or dioxide on the back which overcomes
>   a lot of the problems).  In practice, the sapphire bead doesn't touch the
>   back and we rely on radiative coupling to the bead (which isn't too bad at
>   high temps).

Thermocouples at substrate heater do not touch enough also in our
system.    I do not believe the temperature of the thermocouple.
It changes from +100 to -100 degree C while a substrate is rotated.

>   The system is calibrated using the Al/Si eutectic temperature.  We have
>   looked at using the oxide desorption temperature but seem to have a problem
>   with our substrate cleaning so that the desorption temperature appears
>   to vary by about 50 C from run to run.  (Anyone willing to tell me 
>   EXACTLY what their favourite cleaning recipe is?? - I've seen lots of
>   very brief descriptions but no real details.  We currently use a sulphuric
>   acid / hydrogen peroxide etch.)

I think the reason of the errors of your pyrometer cannot be put
the blame on your pyrometer.     The temperature showed by
pyrometer dependes on solid angle to the substrates so that the angle
of the substarates are not constant in each run.

>   Anyway, the problem (at last) is that we need to measure lowish temperatures
>   now (of the order of 300-500 C) and we would like some recommendations of how

In our laboratory, Tsub is calibrated by Al/Si for high
temperature (for GaAs and AlAs growth) and Au/Si for low
temperature (for InAs growth).  And I get the relation between the
Tsub and the heater current.  The lineality of the heater current
and Tsub is also checked with pyrometer in the region between 
the eutectic temepratures of Al/Si and Au/Si .

In practice, windows get more and more dirty with As(GaAs?) in
every runs.    I think pyrometer cannot bring true results in any
time.    What I believe is the heater current and RHEED pattern.

If you want to get more detail about our fasion, please send
e-mail to me.   ( But I cannot say 'leave it to me!'. )

--
===================================================
$@5~ETBg3X9)3XItEE5$9)3X65<<(J  $@:4!9LZ8&(J$@5f<<(J  $@1'Ln(J $@OB9T(J
                    e-mail : uno@kuee.kyoto-u.ac.jp
Newsgroups: sci.materials
From: catlett@owlnet.rice.edu (Steven Charles Catlett)
Subject: Bullet Proof Heat Shield
Organization: Rice University
Date: Thu, 1 Oct 1992 18:26:11 GMT


Hi, I am a materials science undergrad at Rice University.
We have been given a project to design and build a bullet
proof heat shield.  The shield must be 30 cm by 30 cm.  The
requirements state that the shield must withstand 2000F for
10 minutes (applied with an oxyacetylene torch) and the
backface temperature can reach no more than 212F.  After this
portion of the test, the shield will be shot 3 times with a .22
rifle at 50ft and then tested again with the torch (in one of 
the locations of impact).  Weight is the primary consideration,
but we are operating on an extremely limited budget ($250)
so we are hoping for donations or cost sharing in exchange 
for a copy of our data/conclusions.  Any suggestions for 
designs, materials or helpful people to contact would be 
appreciated.



Steve Catlett
catlett@owlnet.rice.edu  
Newsgroups: sci.materials
From: rubin@skiing.cis.ohio-state.edu (Daniel Rubin)
Subject: Plastic Suppliers Needed...
Organization: The Ohio State University Dept. of Computer and Info. Science
Date: Wed, 30 Sep 1992 01:34:05 GMT

Hello all,  I posted a similar article a while back, but didn't get any
response so I figure I would try again...

I am looking for a supplier of large Teflon piping.  I need anywhere from a
2 inch to a 4 inch diameter pipe with anywhere from a 1/4 inch to 1 inch wall
thickness...

I have the US placstics catalog and all they sell is Teflon rod stock. I 
suppose I could buy a 4 inch rod and bore out the center, but this would be
wastfull and a pain.

Thanks in advance						  - Dan


-- 
  Daniel Joseph Rubin    |  "...A good football team for the alumni, parking
rubin@cis.ohio-state.edu |  for the faculty and sex for the students."
      GO        GO       |  - President E. Gordon Gee on the three things that
    BENGALS  BUCKEYES    |  a great university president must provide.....
From: besr@sepro.odessa.ua (Anatoly K. Bezrodnyh)
Newsgroups: sci.materials
Subject: I seek for partners in ultra-dispersion powders of metal oxides manufacturing
Keywords: ultra-dispersion powders metal oxide
Date: 5 Oct 92 09:45:17 GMT
Reply-To: besr%sepro.odessa.ua@USSR.EU.net
Organization: Sepros Corp. Int.

Dear Sirs!

Please let me introduce you the Research and Development
Laboratory of Ukrainian-American Joint Venture "Sepros Corp.
Int.". Our company profile is scientific research in production
ultra-dispersion powders of oxides of metals.

One of the latest workings of Laboratory is the high purity,
ultra-dispersion powders of oxides of metals.

We are manufacturing ultra-dispersion powders according to original
technology (Gas Dispersion Synthesis).

Gas Dispersion Synthesis - it's special way of combustion of
suspensions of solid fuel in gas for receiving of target products such
as oxides, nitrids, halkogenids etc. Gas Dispersion Synthesis is:

     uniterrupted technological processes;

     absence of ecological problem;

     insignificant usage of electric power;

     compact and completely automation equipment.

The characteristics of powder of oxide of aluminium is:

     1) chemical purity - 99,95%;

     2) size            - 0,09 micron;

     3) shape           - sphere.

Now our production program is aluminium oxide (100 kg per
month). But we can provide an essential increase if there is a
good market for this production.

Also We are manufacturing ultra-dispersion powders of oxides of
zirconium, iron and synthetic shpinel.

We should like to market for our productions and our technology
or set up Joint Venture. We are looking for partners in this
deal.

If you are interested in the subject, I send you any information
on your request. If you aren't, but know anybody may be, please,
send me a message. I'll be very grateful for any advice.

I'm looking ahead for your reply at address:

E-Mail: Internet - besr%sepro.odessa.ua@USSR.EU.net
        Relcom - besr@sepro.odessa.ua

Post:   Ukraine, 270088, Odessa, Box 256

Phone:  (7-0482)450143, (7-0482)450281

Fax:    (7-0482)269774

Telex:  232153 ORLAN SU


        Yours faithfully,
        A.Bezrodnykh
        Research Director,Ph.D.,
        Sepros Corp. Int.

P.S. Don't use "From:" address to reply if your site isn't in
Relcom. From Internet reply to besr%sepro.odessa.ua@USSR.EU.net
or to besr%sepro.odessa.ua@relay.USSR.EU.net.
From: 5916rahmank@vms.csd.mu.edu (K. M. A. Rahman)
Newsgroups: sci.materials
Subject: Re: Uses of Be
Date: 4 Oct 1992 00:26:32 GMT
Organization: Marquette University - Computer Services
Reply-To: 5916rahmank@vms.csd.mu.edu
NNTP-Posting-Host: vmsa.csd.mu.edu

In article <hwbp3dc@dixie.com>, jgd@dixie.com (John De Armond) writes:
|>5916rahmank@vms.csd.mu.edu (K. M. A. Rahman) writes:
|>
|>>	Be is used in nuclear reactors, I think in shut down process.
|>
|>Nope.  That's cadmium or boron.  Be is sometimes used in 
|>sources mixed with Am-241 (called "AmBes" )as a source of neutrons
|>during reactor startup.  AmBes, sometimes with Pu replacing the Am,
|>are also used in the lab as sources of neutrons.
|>
|>>	I also heard that it's highly toxic. 
|>
|>Some compounds are.
|>
|>>What are the spectacular properties?
|>
|>Very light weight, very strong, transparent to X-rays down to very low
|>energies, good neutron moderator, excellent heat conductor, as an oxide, 
|>a very good electrical insulator while being a very good thermal 
|>conductor.  Be is the lightest metal with any structural use.
|>
|>John
|>-- 
|>John De Armond, WD4OQC               |Interested in high performance mobility?  
|>Performance Engineering Magazine (TM) |
|>Marietta, Ga                         |Interested in high tech and computers? 
|>jgd@dixie.com                        |Write me about PE Magazine
|>Need Usenet public Access in Atlanta?  Write Me for info on Dixie.com.

	Thanks for enlightening.
	May we know something about PE magazine?

	-Anis
Newsgroups: sci.materials
From: jgd@dixie.com (John De Armond)
Subject: Re: Uses of Be
Date: Sat, 03 Oct 92 19:28:43 GMT
Organization: Dixie Communications Public Access.  The Mouth of the South.

5916rahmank@vms.csd.mu.edu (K. M. A. Rahman) writes:

>	Be is used in nuclear reactors, I think in shut down process.

Nope.  That's cadmium or boron.  Be is sometimes used in 
sources mixed with Am-241 (called "AmBes" )as a source of neutrons
during reactor startup.  AmBes, sometimes with Pu replacing the Am,
are also used in the lab as sources of neutrons.

>	I also heard that it's highly toxic. 

Some compounds are.

>What are the spectacular properties?

Very light weight, very strong, transparent to X-rays down to very low
energies, good neutron moderator, excellent heat conductor, as an oxide, 
a very good electrical insulator while being a very good thermal 
conductor.  Be is the lightest metal with any structural use.

John
-- 
John De Armond, WD4OQC               |Interested in high performance mobility?  
Performance Engineering Magazine (TM) |
Marietta, Ga                         |Interested in high tech and computers? 
jgd@dixie.com                        |Write me about PE Magazine
Need Usenet public Access in Atlanta?  Write Me for info on Dixie.com.