Subject: Re: Publishing Scholarly Work on the Web -- opinions?
From: hdc@ornl.gov (Hank Cochran)
Date: 11 Sep 1996 17:32:05 GMT
In article , kkereke@iamerica.net (Kirk Kerekes) writes:
...snip
|> Silly comment 1:
|>
|> Why would anyone _pay_ to do this?
Not I. Not unless it was peer-reviewed and archived.
|>
|> Silly comment 2:
|>
|> I suggest organizing your publications area into two major subdivisions:
|> A) Publications that are totally un-vetted, and
|> B) Publications that have been passed on by someone in the field to verify
|> that they aren't techno-gibberish. This would not be the same level of
|> validation as a formal peer review, just a filter to separate the
|> quixotically absurd from the merely implausible.
Absolutely! And make it easy for me to avoid category A.
|>
|> Silly comment 3:
|>
|> Accept advertising, and skip the fees.
Good idea.
--
--------------------------------------------------------
H. D. Cochran tel 615/574-6821
Chemical Technology Division fax 615/241-4829
Oak Ridge National Laboratory email hdc@ornl.gov
Oak Ridge, TN 37831-6224 (USA)
--------------------------------------------------------
Subject: Re: Wind powered water oxygenator materials
From: Dan Bollinger
Date: Wed, 11 Sep 1996 10:34:55 -0700
s1045099@iplabs.ins.gu.edu.au wrote:
>
> Hi,
>
> The faculty at my university are working on a wind powered water
> reservior oxygenator. A shaft will connect a vertical axis wind turbine to an
> underwater impeller-deflector assemply through a floating pontoon and the
> whole thing will be anchored to the bottom. The deflecter is basically a
> concaved cone that deflects the water coming from the rotating
> impeller away from the bottom.
> I thought perhaps that the impeller-deflecter assembly could be replaced by a
> radial impeller as in a centrifugal pump but this may be too expensive to
> manufacture.
>
> Can anyone suggest what types of materials they should consider for the
> impeller, the wind turbine blades, the shaft anf the flow deflecter?
FRP, fiberglass reinforced plastics are definitely worth considering,
especially if you are interested in quantities. It is also easy to mold
or fabricate parts including complex shapes like impellers. Also, unlike
SS, they won't be stolen and sold for scrap!
Have you done or found any research on aeration methods? Many sewage
treatment plants use them. What is the method which intrains the most
oxygen for the least energy?
If you have any sketches, I'd be happy to look at them and advise. I've
done a lot of large part FRP design including impellers, and some boat
design as well, not to mention an interest in preserving our waterways.
Good luck,
Dan Bollinger
Industrial Designer
Subject: Re: Wind powered water oxygenator materials
From: Dan Bollinger
Date: Wed, 11 Sep 1996 10:35:05 -0700
s1045099@iplabs.ins.gu.edu.au wrote:
>
> Hi,
>
> The faculty at my university are working on a wind powered water
> reservior oxygenator. A shaft will connect a vertical axis wind turbine to an
> underwater impeller-deflector assemply through a floating pontoon and the
> whole thing will be anchored to the bottom. The deflecter is basically a
> concaved cone that deflects the water coming from the rotating
> impeller away from the bottom.
> I thought perhaps that the impeller-deflecter assembly could be replaced by a
> radial impeller as in a centrifugal pump but this may be too expensive to
> manufacture.
>
> Can anyone suggest what types of materials they should consider for the
> impeller, the wind turbine blades, the shaft anf the flow deflecter?
FRP, fiberglass reinforced plastics are definitely worth considering,
especially if you are interested in quantities. It is also easy to mold
or fabricate parts including complex shapes like impellers. Also, unlike
SS, they won't be stolen and sold for scrap!
Have you done or found any research on aeration methods? Many sewage
treatment plants use them. What is the method which intrains the most
oxygen for the least energy?
If you have any sketches, I'd be happy to look at them and advise. I've
done a lot of large part FRP design including impellers, and some boat
design as well, not to mention an interest in preserving our waterways.
Good luck,
Dan Bollinger
Industrial Designer
Subject: steel tensile test: ASTM or DIN
From: jnieuwsma@aol.com (J Nieuwsma)
Date: 11 Sep 1996 14:37:13 -0400
My copmany buys carbon steel castings, ASTM A216 Grade WCB, from several
foreign foundries. A216 specifies chemical and physical properties, and
references ASTM A703 for the dimensions of tensile test specimens.
However, the text of A703 is unclear; the test bar parameters listed
therein may be interpretted as suggestions rather than rigid requirements.
One of our suppliers wants to use test specimen dimensions in accordance
with a DIN standard rather than A703. They have not specified which DIN
standard.
A search of my usual references hasn't shed any light on the subject.
My questions:
1. Which DIN standard covers tensile test specimens for carbon steel
castings?
2. How rigid are the requirements of A703?
3. Are DIN standard test specimens acceptable for A703?
4. What references (handbooks, catalogs, web pages, etc.) would have this
information so I don't have to bother the newsgroup next time?
Any help would be apprectiated!
Jonathan Nieuwsma
Subject: Re: QUES:PLEASE HELP:Mode
From: paul.suleski@pc-aug.com (Paul Suleski)
Date: Wed, 11 Sep 1996 12:25:00 GMT
>From: Michael White
>Subject: Re: QUES:PLEASE HELP:Model for cracking whip
>
>M.E. Moore wrote:
>>
>> Vincent R. Johns wrote:
>> >
>> > (posted and emailed)
>> >
>> > John Hinkey wrote:
>> >
>> > > >atman wrote:
>> > I believe that baseball
>> > pitchers can throw balls at more than 10% of the speed of sound
>> > (i.e., their hands presumably move that fast at some point), so it
>> > seems not unreasonable that the end of a whip can move far faster
>> > than that.
>> > -- Vincent Johns
>>
>> I think that TOP speed for a baseball is about 120 mph.
>>
>> --
>> M.E. Moore
>> Los Alamos, NM
>
>Actually it is less than 120 mph.
Mine, too. I stopped by a radar exhibit at the Phoenix Science
somethingorother the other day. A crowd was throwing tennis balls
at a target. My best registered 47 mph, so I guess my pitching
days are over. ('Course, that was also true 30 years ago, heh, heh.)
___
* UniQWK v4.2 * The Windows Mail Reader
Subject: Re: Granular bulk mat'l flow
From: paul.suleski@pc-aug.com (Paul Suleski)
Date: Wed, 11 Sep 1996 12:16:00 GMT
>From: "John E Youngk"
>Subject: Granular bulk mat'l flow control
>
>I'm presently developing a valve to control the flow of gravity fed
>granular materials to 1% accuracy.
>Clam shell - deflected flow/load cell concept.
>Do you know of similar devices??? needs???
>email or call john @ 1-800-879-7955
Depends upon what you're doing with the flow. Years ago (early
60's) I worked for the manufacturer of Weigh-Kon continuous flow
gravimetric feeders for packaging lines. It used a balance scale
preset to specific weight. A cup at the end was in the continuous
stream of gravity flow material until the weight was reached. The
balance tripped, bringing a surge cup into the stream while the
weight cup dumped into the chute. When empty, the weigh cup swung
back up, tripping the surge cup to dump into it. It was (perhaps
still is) strictly a mechanical device, and extremely accurate.
Manufacturer: Jabez-Burns-Gump of Chicago. I left the company
shortly after they were acquired by White Consolidated, which moved
the Chicago operation to Buffalo, NY (my reason for leaving).
___
* UniQWK v4.2 * The Windows Mail Reader
Subject: Re: QUES:PLEASE HELP:Model for cracking whip
From: tony richards
Date: 11 Sep 1996 16:41:30 GMT
Patman wrote:
>Dear all,
>As usual please forgive me if this question does not concern this group
>directly and/or if this has been discussed recently.
>
>My question:
>Can anyone tell me or at least point me in the right direction. I am
>looking for the mathematical 'simplified' (if exists) model of the whip.
>That is to say the model which describes the traveling wave from the
>relatively slow wrist action of the user to the high velocity crack as it
>reaches the end at speed of sound.....
>Any help, information, books and/or web sites that might contain
>something a long these lines would be greatly appreciated.
>Many thanks,
>regards,
>--
ANy text on waves and vibration should tell you that a travelling wave reaching
the free end of a piece of string should be reflected IN PHASE WITH THE INCIDENT WAVE.
This means that within the time that it takes for the amplitude of the displacement of
the tip of the string to go from zero(just before arrival of the first disturbance)
to the full amplitude of the incident wave, the displacement of the tip will go from
zero to twice the amplitude of the incident wave (since the incident and reflected wave
add IN PHASE in this case).
This time is just 1/4 of the period of the wave, T. call this T/4
Call the amplitude of the arriving wave A.
Then the tip has to travel from 0 to 2A sideways in a time T/4, giving a mean
velocity 2A/(T/4) which is just 8A/T.
for this speed to exceed the speed of sound in air S (say 1000 feet/second)
it must be true that 8A/T>S=1000, or A/T>125 feet/sec.
All you have to do is to get a big enough amplitude (A) and ensure a small enough period T
for the wave.
WHips have a tapering cross section (though to get a 'crack' out of a string its not essential)
and the effect of this is to speed up the wave travelling
along it, in much the same way as light waves travelling into a medium of lower refractive
index speed up (thinner string equates to lower refractive index).
A faster-moving wave has smaller T, which all tends to enable the inequality to be
satisfied and the tip to break the sound barrier - hence the crack.
--
Tony Richards 'when I was a very young I had this strange'
Rutherford Appleton Lab 'feeling of being trapped in a young girl's body'
UK 'then I was born and it all worked itself out ok'
Subject: Bolted connections in composites
From: Russell_Michael@hq.navsea.navy.mil (Russell)
Date: 11 Sep 1996 18:27:52 GMT
I'm reviewing someone else's design of a bolted connection in a composite
structure (a metal plate loaded parallel to a glass reinforced plastic
plate with several bolts in essentially single shear). When I design
this sort of thing, I use the bearing strength of the laminate as one of
the parameters in selecting the number of bolts and laminate thickness,
and take sigma(b) as the compresive strength of the resin, not the
laminate (these laminates are marine quality with Vf on the order of 35%,
not aerospace laminates). This gives me a warm, fuzzy feeling that the
bolted joint (part of a hoisting fitting with factors of safety applied)
won't fail or egg out the bolt holes even over many load cycles. There's
a ratio of about 1:2 between the compressive strengths of neat resin and
reinforced resin.
I vaguely recall having read something which caused me to take my
approach, but can't remember where. A lower value for bearing strength
than compressive strength in composites (as opposed to typical values for
metals) seems reasonable in view of the steps that must be taken to
prevent bearing failures at the ends of composite coupons tested in
compression, but I haven't found any data for bearing strength of
composites. A NASA publication "Simplified Procedures for Designing
Composite Bolted Joints" uses the compressive strength of the laminate,
which seems to contradict my thinking.
Ordinarily, this wouldn't be an issue since the weight and cost penalty
of designing by my approach is negligible, but I have to be able to tell
the other designer whether he's right or wrong, and due to contractual
implications, I have to _prove_ he's wrong or forget the issue. Any
thoughts or recommended sources of information?
Subject: Re: FEA: Modelling Bolt Holes
From: sendscot@nameserver.pwfl.com (Scott Sendlein)
Date: Wed, 11 Sep 1996 16:29:18 GMT
In article <5115cl$gsj@arl-news-svc-6.compuserve.com> <71531.3213@compuserve.com> writes:
>
>I am currently using MCS/Nastran and have had to analyse a few models which included bolted joints.
>
>I have tried hexagonal holes at the diameter of the bolt body, with rigis elements jointing adjacent "bolted" nodes,
>but the localized stresses look to be unrealistic. So I tried an outer hexagonal ring to match the bolt's head diameter,
>with rigid elements (again high stresses) and then beam elements (better) jointing at the outer ring, with the inner ring
>left dangling. I have also had problems with adjacent plate structures passing through each other based on the
>external loading consditions, and laid in some compressive-gap type elements to shore things up.
>
>Am I nuts, or what? Is there a simpler (yet still effective) way to model bolted joints? Is there a range of
>approaches applicable for the class of problem (shear loading, slip critical, tension only, bolting flanges, and
>so on....
>
>Anxiously awaiting a reply...
>Steve Sywak
Steve,
It sounds like you desire good stress results in the flanges in the vicinity of
the bolts, and not just a good simulation of the interaction between two
flanges that are bolted together. If you require a good estimation of stress
in the region of the joint, then I think you must model the bolt and flanges,
with contact elements where the bolt and nut faces contact the flanges, and
where the flanges contact each other. I typically use contact elements
(as opposed to coupling) because my loadings tend to have bending in them and
local separation of flange faces is possible. Also, use of contact elems.
where the nut (or bolt head) contacts the flange permits specification of
an initial interference (the preload). Modelling the preload accurately is
absolutely essential in predicting stresses in the bolt and flange with any
kind of success.
Additionally, if you are attempting to model a bolt circle type of situation,
and are trying to do a 2D axisymmetric model, there are some other tricks
that you would need to do to account for the fact that the bolts and the
material between bolt holes (in the flanges) are nonaxisymmetric. If that
is your situation, email me and I can talk to you more about that particular
case.
______________________________________________________________________________
L. Scott Sendlein Voice: 407-796-6555
Lifing Systems & Adv. Struct. Concepts Group Fax: 407-796-8993
Turbine Component Center Email: sendscot@pwfl.com
Pratt & Whitney - GESP
PO Box 109600
West Palm Beach, FL 33410-9600 Mail Stop: 714-03
______________________________________________________________________________
Subject: Is there a NASTRAN units converter?
From: Jill Marlowe
Date: Wed, 11 Sep 1996 17:12:30 -0400
I know its a dream, but...
I have two NASTRAN(MSC) models which I need to integrate. Unfortunately,
one was created using mm-N-s and the other in inch-lb-s. Does anyone
know of a utility that will convert between the units? I use PATRAN as a
pre/post-processor, and it will handle scaling of geometry, but not
material, beam, shell, solid, load, etc. properties. I am hoping to find
some FORTRAN, C or PATRAN PCL code.
Please reply to my email address if you can help.
Thanks,
Jill
--
___________________________________________________________________________
Jill M. Marlowe Structural
Analysis
j.m.marlowe@larc.nasa.gov Engineering Analysis
Branch
(804)864-xxxx Voice:7027,Fax:7202 Aerospace Mechanical Systems
Division
___________________________________________________________________________
NASA Langley Research Center, MS 431, Hampton, Virginia 23681
Subject: Re: Publishing Scholarly Work on the Web -- opinions?
From: Chad English
Date: Wed, 11 Sep 1996 14:27:26 -0400
Well, I've had thoughts along the lines of Web publishing too. I already plan to
put my publications (including theses) on my web pages (with permission of the
publication source, of course). I've also downloaded several in postscript format
over the Web that I've found interesting. Here are some of the pros and cons I've
come up with:
Pro (for literature searches):
1. It is *extrememly* convenient.
2. It is much faster than the slow search in the library which only turns up a
portion of the relevant papers. (I have about a dozen I've found lately that I
wished I had included in my Master's.)
3. It is much cheaper. Photocopy costs are enormous for me, plus I've had to order
in photocopies of papers that I *think* are relevant but turn out not to be. It
would be virtually free to store them all on disk (except the price of the disk of
course), and much cheaper (and neater) to print them out rather than photocopy. (It
costs me 2 to 3 cents per page to print at home, 9 cents per page to photocopy in
the library, up to $5 for some photocopies ordered in from other sources).
4. It is easier to determine relevance to your work. I read 10-20 page papers where
I wish I could just do a text search for keywords to find out what they said about
the specific aspect I'm looking for.
5. I've come across interesting articles on the Web that I would never have even
searched for in a library because they are not relevent to the work. I still find
other areas of research interesting but I'm not willing to spend the time searching
through the library for all papers I might find interesting in all other fields.
Cons (for literature search):
1. None
Pros (for publishing):
1. It lets your work be more widely available. Your paper has the same chances of
being found and referenced as all others. Most people do not find papers from tiny
obscure journals or conferences. Large international conferences and journals are
easy to find and get referenced more. This is not necessarily because the work is
more important. Money can be a factor (to go to a conference), the field of study
is not as prominant, competition (too many papers, too few spots), and so on. Web
publishing would level the playing field.
2. You could include mulimedia. Often animations can show 3D graphs or mechanism
operation in much better detail. Video can show experimental procedures and
results. Of course you can't print this stuff out, but you don't need to print
something out to reference it. (Hardcopy printing for passing information is on
it's way out anyway).
Cons (for publishing):
(a) In the case of putting only published works (conferences, journals) on the Web:
1. You must convert from the required publishing layout (in whatever text editor) to
HTML. This may change the layout, which isn't really a big deal to the content, but
some people may not like it. Proper layout in HTML (probably using exact spaced
columns of a table) may make this problem avoidable, but you still have less freedom
to layout in HTML. Printing in .pdf format may be another solution since pdf can
now be read on the Web, hypertext links can still be included, and the format stays
the same as what it was in your word processor, plus you don't have to write any
HTML code. However, writing in pdf requires expensive software, writing HTML is
free.
2. You may not be able to include multimedia since you can't include it in the
original published paper. You can add it, but that changes the paper slightly.
This isn't really a big deal though.
(b) For the case of publishing on the Web only (not published elsewhere):
1. How do you reference it? With the URL? URLs aren't permanent. They can change,
machines go down, papers would be gone forever, etc. Without a widespread hardcopy
publication, the paper really isn't "permanent".
2. Along the same lines, you can change a paper in HTML format. Again, it's not
permanent. When somebody reads it and references it, there is no guarantee that it
will say the same thing later.
3. There wouldn't be a lot of "prestige" or respect for these publication,
especially if they don't have to go through some sort of peer review first.
My conclusions are this:
1. The best way to go about publishing on the Web is to only put up works that are
already published elsewhere (conferences, journals). This way the document is
permanent, it has gone through peer review, and it has a permanent reference. (Even
if the URL changes.)
2. Preferably it should be printed in pdf format if they ever make a cheap/free pdf
writer and pdf readers become more integrated with Web browsers (you can already get
plug-ins). For now, very carefully formatted HTML may have to do. PDF would also
add to the permanence of the document too since it is a "printed" format like
postscript, ie, you print to a pdf file (it is not directly editable), you don't
save it that way.
Well, these are my thoughts anyway.
--
("`-''-/").___..--''"`-._
`6_ 6 ) `-. ( ).`-.__.`) Chad English
(_Y_.)' ._ ) `._ `. ``-..-' cenglish@mae.carleton.ca
_..`--'_..-_/ /--'_.' ,' http://www.mae.carleton.ca/~cenglish
(il).-'' (li).' ((!.-'
Subject: Re: FEA: Modelling Bolt Holes
From: Kevin O'Connell
Date: Wed, 11 Sep 1996 13:48:04 -0400
-A.RIZZO wrote:
>
> Might it not be a good idea to first ask the question, "What am
> I trying to learn with this analysis?" Or did I miss that one?
>
I always argue with myself on this issue. Engineers have
an awful tendency of telling someone how to make a clock when
they ask what time it is. I agree that the original gentlemen
seems to be confused as to what he was trying to do. I say
"seems" because as with most posts here, there was barely
enough information to use as a basis of advice. It usually
falls to the respondant to make some basic assumptions
about the questioner including but not limited to:
1) Do they know what they are doing?
2) Will they understand any basic jargon I might use
3) Are they just looking for help with their homework?
4) Have they already considered simplier alternatives?
5) Do they know that the way they posed their question
it appears that the answers are 1) no 2) no 3) yes and 4) no.
When I respond I try to give them the information
they request, then sprinkle in a few "by the way" type
comments. Some "how do you" type questions though seem so
basic or so devoid of knowledge on a subject that you
are tempted to begin your answers with:
"First you study math, then physics, then engineering...."
Kevin O'Connell
Subject: Design technology in tyres industry
From: julien@mecapp2.meca.polymtl.ca
Date: Wed, 11 Sep 1996 18:56:12 -0400
Hello everybody,
I'm looking for any informations (references, web sites,...) about the
design technology (methodology, codes, FEA/CAE/CAD softwares) used by
the tyres industries.
Thank a lot. Regards.
************************************************************************
Julien SOULHAT, M.Sc student,
Departement of Mechanical Engineering, Ecole Polytechnique, Montreal,
P.O. Box 6079, Station Centre-ville Montreal, Quebec, Canada H3C 3A7,
Subject: Re: Cork Production Improvements
From: Dan Bollinger
Date: Mon, 09 Sep 1996 11:22:53 -0700
Chris Roach wrote:
>
> I´m looking for some suggestions on ways to improve the productivty of
> cork for use in wine bottles etc. It is a traditional industry here in
> Portugal, and as such methods of production havn´t changed much over the
> years.
> Thanks in advance,
>
> Chris Roach.
Chris;
My first thought was to use teflon too. You can apply it yourself.
Dupont has a solvent applied teflon solution. After the solvent
evaporates, heat the tool until the teflon melts and coats the surface.
Alternatively, why not use a lubricant? It would have to be food grade,
perhaps a paraffin on the exterior of the punch, but not on the interior
where it might affect the wine or sealing properties.
As I understand it, polymer corks are being used. I just heard that a
new, second, resin has been developed for this.
Is the punch simply pressed into the cork, like a steel rule die, or is
it spun, like a paper drill?
If in the end you find that the punch needs frequent sharpening, and
there is no alternative, then why not make the sharpening process easy
and quick?
Dan Bollinger
Industrial Designer
Subject: Re: Cork Production Improvements
From: Woody White
Date: Wed, 11 Sep 1996 23:47:03 -0700
Dan Bollinger wrote:
>
> Chris Roach wrote:
> >
> > I´m looking for some suggestions ...snip...
> > Chris Roach.
>
> Chris;
>
> My first thought was to use teflon too. You can apply it yourself.
> Dupont has a solvent applied teflon solution. After the solvent
> evaporates, heat the tool until the teflon melts and coats the surface.
I was under the impression that teflon will char, not melt. When burned
will liberate hydrogen fluoride (+ H2O = Hydorfluoric acid - a NASTY!).
-Woody
...snip...
>
> Dan Bollinger
> Industrial Designer
--
de Woody (WB4QXE) - woody.white@worldnet.att.net
Electron Microscopist/Microanalysist,
Ham radio "homebrewer", shade tree mechanic,
'90 Nissan 240SX, wish still had my Mcycle too!
http://www.geocities.com/capecanaveral/3722
.