Newsgroup sci.engr.mech 26881

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Andreas Haffner (ahaffner@aft.sn.no) wrote:
: kirchweg@sztms.tu-graz.ac.at (Gerhild Kirchweger) wrote:
: >4. And that's the crucial part: They are not reciprocating engines expected
: >to have some power output. A 2-or 4-stroke engine is expected to get all the
: >cyliner empty and clean, before the next fresh air comes in, so all the
: >available space can be used for a new cycle. As the engine rotates rather
: >fast, there isn't much time for that task, so the exhaust gas has to rush
: >out in a hurry. It does that only if it's eager to expand (i.e. hot and
: >under high pressure).
: 
: I don't think so! For 4-cycles: It's simply the piston pushing the gasses out
: thru the port. Nothing to do with the gasses pressure. For conventional
: 2-cycles it might be somewhat different.
No, even 4-stroke engines are not only driven by the piston, otherwise there
would be no need for the extensive exhaust manifold- and pipe-system that's
required to keep the engine reasonably quiet.
The noise coming from the exhaust are the shock waves from the expansion.
-- 
oo_oo_oo_oo_oo_oo_oo_oo_oo Gerhild Kirchweger oo_oo_oo_oo_oo_oo_oo_oo_oo
|____ Department of Internal Combustion Engines and Thermodynamics ____|
|__ Graz University of Technology/ Austria ___Tel. ++43 316 873 7212___|
oo_oo_oo_o http://fvkma.tu-graz.ac.at/~gerhild/gerhild.html _oo_oo_oo_oo

For Sale     Miller Startig 200 dc tig welder with foot control.
             Used with tender loving care in University physics workshop.
             Can be tried and tested.
             =A3925.00 only
             Phone Bob on 01203-523409

If You are working with design of machinery exported to the the European 
market, You need to know the rules for CE marking. 
Find them on http://www.gardo.se/CE.

Does anyone know who can supply 0.8 UNM Taps
in UK or USA 

Hi,
Can anyone help with the modelling of the bending stresses in the end plates of a multilayered 
rope winch drum. I am interested in the bending stress caused by the axial load induced by the 
rope.  AS1418:1 Appendix I for those of you who have it, gives reference to German article on the 
matter and presents the results in a graphical form. The bending stress given is f=6*K*P/T^3 
where K is a constant dependent on the drum to rope diameter ratio and the number of layers of 
rope on the drum, P is the rope tension, T is the end plate thickness. Trouble is I don't know 
the assumptions upon which the formula is based. It is unclear if the rope is assumed to be under 
full tension for the entire length of lift and given the errors in the code I'm loathed to accept 
it. The winder drum we are looking at is for a deep shaft. It has a very short drum, a thick 
shell, flexible end plates and 7 layers of rope (yuk!) if that helps.
Thanks
Chris Meimaris

P Barnes wrote:
> 
> onielsen@bart.nl@mail.bart.nl wrote:
> 
> >>
> >>Ok, so you won't answer the question.  I'll try, though I am not an
> >>engineer.  But I was a boilerman.  And I have a few questions.
> >>
> >>1. Every car I've had uses more gas in the winter. (weak, but hey)
> >>2. A car engine wants to operate at @195F degrees, if only for purposes
> >>...
> 
> >Your higher fuel consumption in winter is not necessarily caused by lower
> >engine efficiency but by higher aerodynamic drag on the car. If the air is
> >say 30 degrees C colder in the winter it will be about 10% denser. This means
> >10% higher drag that must be compensated by higher power output from
> >the engine.
> 
> Ok so if the air is denser, then more O2 in the intake, so engine is
> slightly more efficient.  
But most injection systems I am aware of attempt to balance the air mass
flow rate with the fuel delivery, so more O2 simply results in more
fuel, NOT resulting in higher efficiency.
> One factor in lower fuel mileage in winter is the fact that the engine
> is run richer during warm up.  Especially if short trip driving occurs
> often.
This is just the point the originator of this thread was trying to make!
Regards,
William R. Stewart
Member American Solar Energy Society
Member Electrical Vehical Association of America
"The truth will set you free:  - J.C.

Can anybody assist with a problem I have in a gold mine in western
Australia.
We have a 36 foot Sag Mill with a gearbox driven to a 11kw  or 3.8
Megawatt Electric Motor.
The gearbox has recently failed due to shaft voltage being conducted
through the internal bearings.
A check was done recently by the sparkys and they found 6 volts
travelling through the g/box.
Can anybody explain what is  shaft voltage in rotating machines, how
it is caused and how to eliminate it.
The mill has an annual output of aout 2.5mtpa.
Regards
Steve HULL
Kalgoorlie
Western Australia
pd05831@gold.iap.net.au

Actually, my results indicated divergent displacement under point load, not 
zero stress or infinite displacement.
Paul Kurowski

Darren D. Schmidt wrote:
> Series 1 Question 1
> 
> Why are the spokes on a bycycle tangential and the spokes on a connestoga
> wagon radial?
Wagon wheels don't have to transmit torque, a bicyle wheel does. There
are some ultralight bicycle wheels that are radially laced, however
they cannot be used on the rear wheel or with disk brakes.
Kurt

> >Why are the spokes on a bycycle tangential and the spokes on a connestoga
> >wagon radial?
> 
> Is it because the bicycle spokes support the load in tension, while the wagon
> spokes are in compression? 
Precisely.  There is an excellent book (I forget title and author, but I
could get those for you) about wheel building for bicycles.  It
considers various aspects of tension in spokes, etc.  FEA studies on
wheel loading are included.
-Paul

CALL FOR PAPERS
1997 ASME Pressure Vessels and Piping Conference
"International Advancement in PVP Technology"
July 27-31, 1997, The Peabody Hotel
Orlando, Florida, U.S.A.
'NDE Research'
The NDE Engineering Division of ASME is soliciting papers for 
presentation and
publication in the area of "NDE Research".
The general topics of interest are:
* Inspection methods at elevated temperature and pressure
* Design of sensor arrays
* Noncontact sensors
* Probability of detection
* Automated and robotic inspection systems
* Technology transfer
Abstracts are to be submitted by Oct. 10, 1996; Authors will be notified 
of
abstract acceptance by October 15, 1996; Draft Papers are to be 
submitted by November
30, 1996; Final Papers must be submitted by March 1, 1997.
For each proposed paper, please send a 150-200 word abstract and the 
contact author's
complete affiliation, address, telephone and fax numbers to:
Marty Jones, Ph. D.
Senior Research Engineer
NDE Technical Team
EWI, Materials Joining Technology
1250 Adams Drive
Columbus, OH  43210
Phone:  (614) 688-5146     Fax: (614) 688-5001
http://www.ewi.org     e-mail:  mpjones@ewi.org

Announcing the International Workshop
on Advanced Materials for Marine
Construction.
Dates: February 5-7, 1997
New Orleans, Louisiana
Sponsors:
U.S. Minerals Management Service
American Bureau of Shipping
American Welding Society
Organized by:
Colorado School of Mines
Content Summary:
Advanced materials have contributed to 
significant progress in marine structures 
engineering in the past decade. Composite 
materials, weldable high-strength steels, 
duplex stainless steels, and titanium and 
aluminum alloys that are compatible with 
offshore environments offer the marine 
industry improved corrosion resistance 
and strength-to-weight ratios; but material 
costs, lack of fabrication expertise, and 
differences in design philosophy still 
present significant barriers to more 
widespread use.
Producers, designers, engineers, fabricators, 
inspectors, and users of marine materials, 
including corporate and government leaders, 
will define the current state of use of advanced 
materials in marine structures, and identify 
technical and non-technical barriers to more 
widespread use.
The Workshop is designed to achieve the following 
objectives:
¨ Define current use of advanced materials marine engineering
¨ Identify barriers to more widespread use of advanced 
materials in marine engineering
¨ Provide an international forum for participants from all 
aspects of materials production and use
¨ Promote the cost-effective use of advanced materials in 
marine structures
¨ Produce an archivable record of current usage and future 
opportunities for advanced materials in marine engineering
Registration fee: $200.
For further information and/or to
receive a brochure, contact the 
Office of Special Programs and
Continuing Education at the Colorado 
School of Mines at: space@mines.edu
or call 800/446-9488 ext.3321.

Conference Proceedings Available
The following proceedings are available from the Colorado 
School of Mines Office of Special Programs and Continuing 
Education.
All prices are **postpaid** within the U.S.  Contact us for 
outside U.S. shipping prices.
***A copy of the table of contents of each volume can be 
e-mailed.  Contact the address below.***
1)  4th Tunnel Detection Symposium on Subsurface 
      Exploration Technology, April 1993, Denver, Colorado  
$25.00
2)  Third International Symposium on Mine Mechanization
      and Automation, June 1995, Golden, Colorado
      (2 volumes) $50 per volume      
3)  Rocky Mountain Symposium on Environmental Issues
      in Oil and Gas Operations, Golden, Colorado
      1994 and 1995 conference proceedings available.
       1994 edition: $25.00; 1995 edition: $50.00
4)   North American Tunneling ‘94, Conference and Exhibition
       June 6-9, 1994, Golden, Colorado $25
5)  International Workshop on Underwater Welding of Marine
     Structures, Dec. 7-9, 1994, New Orleans, Louisiana $20
6)  15th International Conference on Ground Control in Mining
     August 13-15, 1996. $100 (2 volumes) 
Credit cards and purchase orders accepted.  For further details 
contact the Earth Science Resource Center of the Colorado 
School of Mines at: jproud@mines.edu
Visit our home page on the World Wide Web at:
http://www.mines.edu/Outreach/Cont_Ed/esrc.shtml

I am looking for a method of measuring the percentage on water in oil, I 
know there are units available from companies such as UCC, but I need a 
more bare bones explanation.
During my research I have come across two systems;
	One measures the refractive index of infrared light as it passes 
through the oil, the amount of refraction is proportional to the amount 
of water present in the oil.
	The other system ( which is a more descrete sampling system ) 
takes a small sample of the oil and heats it to a set temperature. The 
oil then "crackles" (like a chip pan) the intensity of this sound is 
proportional to the amount of water present.
	Could anybody sent me research data or other methods for 
measuring water in oil.
Thankyou very much.
Geoffrey Swales.

ANNOUNCING A WORKSHOP ON
BULK SOLIDS HANDLING TECHNOLOGIES
November 4-8, 1996
Colorado School of Mines
Golden, Colorado
Organized & Instructed by:
Centre for Bulk Solids & Particulate Technologies
(Australia) and
Colorado School of Mines
Almost all modern industries handle or process bulk
solids or powders in some form.  The relative costs of
storing, handling, and transporting bulk materials are
increasingly being recognized as crucial factors in 
both manufacturing and processing competitiveness.
The Workshop is designed to provide developers, 
users, and vendors of bulk flow/storage systems and
equipment with essential knowledge and hands-on
experience in the areas of system design, equipment
selection, problem solving, and new technologies.
Major topics include:
>Principles of Granular Mechanics
>Bin Flow Patterns & Characteristics
>Strength & Flow Properties - Hopper Design
>Design - Gravity Bins, Silos & Stockpiles
>Bin Wall Loads
>Flowrate & Blending Analyses
>Numerical Modeling of Granular Flows
>Feeding & Transfer
>Case Studies
Registration fee is $1,495.00 (US)
For more information on registration, accommodations,
and speakers, contact the Office of Special Programs
and Continuing Education at 303/273-3321.
E-mail: space@mines.edu
Fax: 303/273-3314
For a complete listing of upcoming short courses and
conferences, visit our home page on the world wide web at:
http://www.mines.edu/Outreach/Cont_Ed/shortcourses.shtml

In article <324DD85A.2D6C@julian.uwo.ca>, kurowska@julian.uwo.ca says...
>
>Pro/MECHANICA from Parametric Technology Corporation (formerly from RASNA) has been 
>specifically designed for use by Design Engineers, not FEA specialists. It is very easy 
>to use and to learn. I use it to teach a computer hands-on FEA seminar for the Society 
>of Automotive Engineers (SAE) and I have experience with almost hundred people. I have 
>only a few minutes to teach them their way around this software before we start working 
>on meaningful examples. The seminar is not software specific but learning Pro/MECHANICA 
>is an added bonus. MECHANICA is a p-code and, as such, is much more robust. Because of 
>p-element adaptability, automatically generated mesh can "recover" from situations (like 
>one element across wall in bending) where a traditional h-software would produce 
>disastrous results. Pro/MECHANICA is not cheap but, in my opinion, well worth it's 
>price.
>
>
>Paul Kurowski
Paul, I believe you should explore all the options before making your
commitment to a given software. We market ME/NASTRAN which is easy to 
learn and offers unlimited capabilities for future applications. Send me 
an e-mail with your fax number and I will be happy to send you some 
literature on the subject. You can call me at 317-474-1300. My company
Hunckler Engineering Inc. Also undertakes consulting assignments in the 
FEA area as well as reviewing clients in-house FEA work.
Regards
Vijay

In article <324DD85A.2D6C@julian.uwo.ca>, kurowska@julian.uwo.ca says...
>
>Pro/MECHANICA from Parametric Technology Corporation (formerly from RASNA) has been 
>specifically designed for use by Design Engineers, not FEA specialists. It is very easy 
>to use and to learn. I use it to teach a computer hands-on FEA seminar for the Society 
>of Automotive Engineers (SAE) and I have experience with almost hundred people. I have 
>only a few minutes to teach them their way around this software before we start working 
>on meaningful examples. The seminar is not software specific but learning Pro/MECHANICA 
>is an added bonus. MECHANICA is a p-code and, as such, is much more robust. Because of 
>p-element adaptability, automatically generated mesh can "recover" from situations (like 
>one element across wall in bending) where a traditional h-software would produce 
>disastrous results. Pro/MECHANICA is not cheap but, in my opinion, well worth it's 
>price.
>
>
>Paul Kurowski
Paul, I believe you should explore all the options before making your
commitment to a given software. We market ME/NASTRAN which is easy to 
learn and offers unlimited capabilities for future applications. Send me 
an e-mail with your fax number and I will be happy to send you some 
literature on the subject. You can call me at 317-474-1300. My company
Hunckler Engineering Inc. Also undertakes consulting assignments in the 
FEA area as well as reviewing clients in-house FEA work.
Regards
Vijay

We used the inorganic zinc primer with epoxy midcoat, and applied one coat
of  silicone alkyd as a finish coat, in order to keep the shine for years.
Because of the complex shapes it was airless and air sprayed.  
   Some of the equipment (low speed mobile) has been in the field 15 years
now, some in NY and LA, and still has the same shine after washing.
Touchup of an infrequent chipped spot is by hand.  
   However, it is not subjected to chips from road debris or abrasion by
soil, and is grounded.

     As a guess, the date thing is a matter of efficiency over rigid rule.
 Most people I know when writing the date and time in one phrase in any
technical sense use intl std : 
     1996:09:30:2225  (i.e., 10.25 pm, September 30, 1996.)  
  When they write just the date, they do so in a communication that will
almost always be received fairly soon, so it is customary to put the most
relevant part first, the day.  Thus, 30 September 1996. which is spoken
September 30, 1996. 
  Informal writings usually have the dates placed as in speech, September
30, 1996, which is  spoken September 30, 1996.
   In other words, as most people who study the language know implicitly
but not necessarily conciously, English, particularly American English
(which is actually at least 15 kinds of English) will adopt anything that
improves communication and./or is more efficient---"rules of the English
language" is an oxymoron..
   Even here, note in the above how the spoken language ascends, while
written choses order as the situation dictates- time is usually more
pertinent to personal contact than year. Most important first.
  Also note the "kinds of English". There are long debates over whether
they are dialects, types, etc., etc. We can't even agree what it is. 
  So it's sort of futile to try to figure out a language that will borrow
any word it needs to communicate, makes up rules as it goes, and is so
useful and widely learned because it doen't follow rules.  Drives teachers
here nuts. 

Hello.
I am looking for a small device to apply a known small compressive load to an optical fiber. The device should place the fiber in diametrical compression (load perpendicular to the axis of the fiber) between two flat plates.  All of the equipment I can find around here is designed for really large loads. I need to be able to control the load in the 0 to 5 pound range. 
Any ideas, suggestions, or pointers would be appreciated.
Thanks,
Craig
*****************************************
Craig M. Lawrence
Ph.D. Candidate
Mechanical Engineering - Design Division
Stanford University
email: milesb@leland.stanford.edu
phone: (415) 725-1595
fax:   (415) 723-3521
******************************************

Ramkumar Narayanan (engdyn19@alliance.net) wrote:
: Robert Schwartz wrote:
: > 
: > Joao P. Martins (jpm@poirot.ist.utl.pt) wrote:
: > : I am looking for syllaby of introduction to programming courses in
: > : mechanical engineering degrees. In particular, I am trying to find out
: > : what programming language is used.
: > : Can anyone help.
: > : Thanks
: > : Joao P. Martins
: > 
: > In my experience, most engineering schools start their first year
: > students in either Pascal or Fortran.  After one of these intro
: > courses, the higher level language of choice is C.
: > 
: > Bob Schwartz
: > ras@altair.com
: Though this has been traditionaly true, when companies look for Mech.
: Engineers who can program, the trend is to look for either C or C++
: programmers. The availability of programming tools for the above
: languages is the most....
I did not think this thread would turn into an argument over which
programming language is "better".  My assumption was that the original
post was written from a "I want to get a jump on my first year of
college" point of view (it looks like the post came from Portugal).
If that is the goal, then Pascal or Fortran, or maybe even Basic should
be learned.  If becoming a software developer is the goal, then no
arguement is made against learning C++.
Bob Schwartz
ras@altair.com

In a previous article, "onielsen@bart.nl"@mail.bart.nl () says:
>>
>>Ok, so you won't answer the question.  I'll try, though I am not an
>>engineer.  But I was a boilerman.  And I have a few questions.
>>
>>1. Every car I've had uses more gas in the winter. (weak, but hey)
>>2. A car engine wants to operate at @195F degrees, if only for purposes 
>>...
>
>Your higher fuel consumption in winter is not necessarily caused by lower 
>engine efficiency but by higher aerodynamic drag on the car. If the air is 
>say 30 degrees C colder in the winter it will be about 10% denser. This means
>10% higher drag that must be compensated by higher power output from
>the engine.
Hello?  Maybe, but don't forget that engines *do* have to run richer
when it's cold (why do we have chokles if they don't?), plus since the
air is denser, the engine needs more fuel per revolution (essentially,
the engine becomes, as you say, 10% bigger with a corresponding POWER
INCREASE), plus you have the heater on and that sucks heat away from
the engine, so you need a richer mixture, plus you don't drive as fast
in the snow, which is bad mileage, plus you spin the tires a lot in the
snow, which is bad mileage, plus there's all of the snow on top of the
car that you're too lazy to brush off, which is bad mileage, plus you
also probably have the defroster on, which runs the A/C system, which
is bad mileage...
No wonder I get 2mpg in the winter.
-- 
'72 429 Thunderbird: Needs front fenders, manual trans swap, and headers!
                                                   Chewy coffee is good coffee.
I speak for myself, but the mumblings represent The Voices.

In article <52rnds$7vr@madeline.ins.cwru.edu>,
P. J. Remner  wrote:
[...]
>Hello?  Maybe, but don't forget that engines *do* have to run richer
>when it's cold (why do we have chokles if they don't?), plus since the
Choking is normally turned off once the engien is warm, In the old days
we pushed the knob in ourself, these days the atuomatic choke soes it
for us.
>air is denser, the engine needs more fuel per revolution (essentially,
>the engine becomes, as you say, 10% bigger with a corresponding POWER
>INCREASE), plus you have the heater on and that sucks heat away from
>the engine, so you need a richer mixture, plus you don't drive as fast
No. Once the choke is off the mixture isn't richer. Any choking
required is to compensate for the denser air, so any richness is due to
denser mixture, not richer in the sense of higher percentage of fuel
vapor.
And the heater does the engine a favor by "sucking heat away", there by
relieving the radiator of some of its work. Your thermostat maintains
your coolant at a more-or-less cosntant temperature regardless of
whether you have the heater on.
>in the snow, which is bad mileage, plus you spin the tires a lot in the
>snow, which is bad mileage, plus there's all of the snow on top of the
>car that you're too lazy to brush off, which is bad mileage, plus you
>also probably have the defroster on, which runs the A/C system, which
>is bad mileage...
>
>No wonder I get 2mpg in the winter.
Maybe it's because you've been driving with the choke on.
-- 
    ********** DAVE HATUNEN (hatunen@netcom.com) **********
    *               Daly City California                  *
    *   Between San Francisco and South San Francisco     *
    *******************************************************

kirchweg@sztms.tu-graz.ac.at (Gerhild Kirchweger) wrote:
>Andreas Haffner (ahaffner@aft.sn.no) wrote:
>: kirchweg@sztms.tu-graz.ac.at (Gerhild Kirchweger) wrote:
>: >4. And that's the crucial part: They are not reciprocating engines expected
>: >to have some power output. A 2-or 4-stroke engine is expected to get all the
>: >cyliner empty and clean, before the next fresh air comes in, so all the
>: >available space can be used for a new cycle. As the engine rotates rather
>: >fast, there isn't much time for that task, so the exhaust gas has to rush
>: >out in a hurry. It does that only if it's eager to expand (i.e. hot and
>: >under high pressure).
>: 
>: I don't think so! For 4-cycles: It's simply the piston pushing the gasses out
>: thru the port. Nothing to do with the gasses pressure. For conventional
>: 2-cycles it might be somewhat different.
>No, even 4-stroke engines are not only driven by the piston, otherwise there
>would be no need for the extensive exhaust manifold- and pipe-system that's
>required to keep the engine reasonably quiet.
>The noise coming from the exhaust are the shock waves from the expansion.
Of course. But you wrote that it is the pressure from the combustion that
flushes the cylinder. Even if we would assume that the pressure outside the
cylinder would be the same as inside after the expansion when the exhaust port
opens the piston would flush the cylinder. It must do so - there is not much
cylinder space left which could keep the gasses when the piston is at the topp.
But okay, you write now "... not ONLY driven by the pistons...". I'm aware that
the dynamics of the gas flows have a considerable influence on many aspects of
the engine design. So my "...simply the piston...nothing to do..." wouldn't
stand very long either ;-)
Andreas Haffner
---------------------------------------------
This is my own opinion!.......?.......I think
Homepage..........http://home.sn.no/~ahaffner

I am doing Impact-experiments and having a though time finding
the Coefficient of Restitution between a Steel Sphere and a 
Thick Steel Plate.
So I am wondering if anyone outthere has that information or know
of a article where I can read about it.
Thanks,
Anders Fredriksson
anders@grip.cis.upenn.edu

Engineering Central (EC) is a website devoted to engineering information 
and to resumes and job postings for engineers.
Here are the jobs posted this week(Sept. 29-Oct.6/96):
     Refinery Process Specialist (LA) 
     Welding Engineer 
     Quality Assurance Engineer 
     Project Engineers 
     Tecnical Sales Engineer 
     Manufacturing Engineer in West Plains, Missouri, USA 
     Senior Hardware Engineer 
     Manufacturing Design Engineer - Los Angeles 
     Networking Product Manager 
If you're interested in more details, go to EC's Job Bank page at:
http://www.interchange.ubc.ca/wtdenham/jobbank.htm
If you're interested in any of EC's other features, such as the resume 
bank, the engineering links, engineering software etc., please visit out 
home page at:
http://www.interchange.ubc.ca/wtdenham/
Bill Denham

Employment Opportunity at Microcosm Technologies, Inc.
   Position: MEMS Design and Applications Engineer.
Microcosm Technologies, Inc. is a dynamic, well funded,start-up
company, committed to developing state-of-the-art design and
analysis CAD tools for the Micro-Electromechanical Systems (MEMS)
industry.
Microcosm seeks a design and applications engineer to work closely
with our customers. Our philosophy is to provide an extremely strong
working relationship with our customers (who are many of the
major players in the MEMS industry). Thus, the candidate must be
able to work with the customer to understand their MEMS device
and help them with their design and analysis using Microcosm's
MEMCAD toolset. In addition to ongoing support, this includes
performing preliminary analyses of customer designs for the purpose
of supporting sales.
In support of our customers, we expect to provide customizations to
the MEMCAD system. As a major customer interface, the candidate
will need to understand the analysis needs of the customer and feed
those back as new system requirements to the software developers. In
addition, the candidate will help to develop the instructional
materials for users of the software as well as run tutorial
sessions.
In addition to our customers, we are presently involved in several
commercial and government research and development contracts
for developing added MEMS CAD tools.  The candidate will help to
support the evolution of these tools as an in-house "expert user."
We envision, in time, providing design and analysis services to
outside MEMS designers. The candidate would be part of the team
who would support this endeavor.
Based on the above design and analysis efforts, the candidate
will be encouraged to deliver technical papers at appropriate
conferences.
**********************************************************************
Job requirements:
Ph.D. (or MS with strong background) in EE, ME, or related experience.
Experience with design and fabrication of MEMS devices.
Experience with modeling of electromechanical or other MEMS systems.
A strong foundation in Physics and Math.
Experience with FEM and/or BEM analysis software.
Very Strong communication skills.
Willingness to travel.
Additional helpful background:
Experience with VLSI layout
IC circuit design
Electroquasistatic fields and forces
Structural mechanics and/or strength of materials
Ability to speak Japanese or Korean
Internet/Web Page skills
*********************************************************************
Microcosm Technologies, Inc. is an equal opportunity employer,
located in Cambridge, Massachusetts. We offer competitive benefits,
with the addition of a stock option plan. We are a rapidly growing
company which should provide accelerated opportunities for career
growth.
If you are interested in this position, send a resume to:
Dr. Stephen Bart
Microcosm Technologies, Inc.
101 Rogers St., Suite 213
Cambridge, MA 02142
or by Email to: sbart@memcad.com
--

Employment Opportunity at Microcosm Technologies, Inc.
   Position: MEMS Design and Applications Engineer.
Microcosm Technologies, Inc. is a dynamic, well funded,start-up
company, committed to developing state-of-the-art design and
analysis CAD tools for the Micro-Electromechanical Systems (MEMS)
industry.
Microcosm seeks a design and applications engineer to work closely
with our customers. Our philosophy is to provide an extremely strong
working relationship with our customers (who are many of the
major players in the MEMS industry). Thus, the candidate must be
able to work with the customer to understand their MEMS device
and help them with their design and analysis using Microcosm's
MEMCAD toolset. In addition to ongoing support, this includes
performing preliminary analyses of customer designs for the purpose
of supporting sales.
In support of our customers, we expect to provide customizations to
the MEMCAD system. As a major customer interface, the candidate
will need to understand the analysis needs of the customer and feed
those back as new system requirements to the software developers. In
addition, the candidate will help to develop the instructional
materials for users of the software as well as run tutorial
sessions.
In addition to our customers, we are presently involved in several
commercial and government research and development contracts
for developing added MEMS CAD tools.  The candidate will help to
support the evolution of these tools as an in-house "expert user."
We envision, in time, providing design and analysis services to
outside MEMS designers. The candidate would be part of the team
who would support this endeavor.
Based on the above design and analysis efforts, the candidate
will be encouraged to deliver technical papers at appropriate
conferences.
**********************************************************************
Job requirements:
Ph.D. (or MS with strong background) in EE, ME, or related experience.
Experience with design and fabrication of MEMS devices.
Experience with modeling of electromechanical or other MEMS systems.
A strong foundation in Physics and Math.
Experience with FEM and/or BEM analysis software.
Very Strong communication skills.
Willingness to travel.
Additional helpful background:
Experience with VLSI layout
IC circuit design
Electroquasistatic fields and forces
Structural mechanics and/or strength of materials
Ability to speak Japanese or Korean
Internet/Web Page skills
*********************************************************************
Microcosm Technologies, Inc. is an equal opportunity employer,
located in Cambridge, Massachusetts. We offer competitive benefits,
with the addition of a stock option plan. We are a rapidly growing
company which should provide accelerated opportunities for career
growth.
If you are interested in this position, send a resume to:
Dr. Stephen Bart
Microcosm Technologies, Inc.
101 Rogers St., Suite 213
Cambridge, MA 02142
or by Email to: sbart@memcad.com
--

P Barnes (pbarnes@iserv.net) wrote:
: onielsen@bart.nl@mail.bart.nl wrote:
: >>
: >>Ok, so you won't answer the question.  I'll try, though I am not an
: >>engineer.  But I was a boilerman.  And I have a few questions.
: >>
: >>1. Every car I've had uses more gas in the winter. (weak, but hey)
: >>2. A car engine wants to operate at @195F degrees, if only for purposes 
: >>...
: >Your higher fuel consumption in winter is not necessarily caused by lower 
: >engine efficiency but by higher aerodynamic drag on the car. If the air is 
: >say 30 degrees C colder in the winter it will be about 10% denser. This means
: >10% higher drag that must be compensated by higher power output from
: >the engine.
Maaybe, but I doubt this is usually significant. 
: Ok so if the air is denser, then more O2 in the intake, so engine is
: slightly more efficient.  I don't know by how much, but shouldn't this
: offset  the "higher drag?"
More oxygen means it will have more power but not necessarily be more
efficient.
: One factor in lower fuel mileage in winter is the fact that the engine
: is run richer during warm up.  Especially if short trip driving occurs
: often.
And that with a colder engine block temperature, you lose more energy from
the fuel combustion to heating up the cylinder walls (heat which is lost)
instead of causing a higher in-cylinder gas pressure which turns into
mechanical work. 
In reality, cold weather is often bad weather, and there are more traffic
jams, and there is less traction on the ground thanks to snow and ice.
--
Matthew B. Kennel/mbk@caffeine.engr.utk.edu/I do not speak for ORNL, DOE or UT
Oak Ridge National Laboratory/University of Tennessee, Knoxville, TN USA/ 
  I would not, could not SAVE ON PHONE,
  I would not, could not BUY YOUR LOAN, 
  I would not, could not MAKE MONEY FAST,
  I would not, could not SEND NO CA$H,
  I would not, could not SEE YOUR SITE,
  I would not, could not EAT VEG-I-MITE,
  I do *not* *like* GREEN CARDS AND SPAM! Mad-I-Am!       (inspired: PvdL)

In article <3250B00F.130C@softopia.pref.gifu.jp>, Joel Shellman
      writes:
[...equation in translational position deleted...]
[...equation in angular position deleted...]
>For the two body problem I'm working on, it's a 15 x 15 Jacobian matrix
>that i solved for symbolically using the above equations and so use that
>to get ther jacobian.
For a two-body problem, I can't see how you can have more than 12 
degrees of freedom -- and that's only if each body is completely free 
to move in 3D.  If you have two bodies connected by a joint, that 
brings you down to seven.  If your base is not free in space (e.g. it's
not a satellite), that brings you down to four -- or fewer.  Depending
on what kind of joints you have.  This 15x15 matrix seems IMPO too 
complex for the problem you're trying to solve.  If you have three 
degrees of freedom, your "jacobian" oughta be 6x6.
>Can anyone suggest what might be going wrong?  I'm not sure if it's just
>because the inaccuracy of double floating points or because my equations
>or what is wrong.  The joint forces used to alternate between 4
>different values but after changing some stuff (using LU decomposition
>instead of Gaussian) now they're getting large.
Double floating points is absolutely your last choice.  If your simulation
is going unstable and just taking off, then you have a sign error.  If
it's 
oscillating and the oscillations are increasing without bound, you have
negative damping being introduced, and that's probably a sign error of
a different kind.
What you really need to do is simplify, simplify, simplify.  Get your 
model down to the least number of degrees of freedom that has any
meaning, and use your simulation to solve a problem that you can 
solve by hand.  Then add a DOF or two at a time until you are 
confident in your results.
Dr. Ron Graham
Project Engineer for Robotics, GreyPilgrim LLC, Philadelphia
founder of sci.engr
EMMA Robotic Manipulator now online - http://www.greypilgrim.com/
"We all know that engineers love to play with expensive toys.
 Especially when someone else is paying for them."
 -  Sir Richard Attenborough, in "Flight of the Phoenix"

Looking for PFATAT software. It is public domain, but cosmic release
is too expensive for me.
Franck
-----------------------------------------------------------
Franck Violette
Southampton,UK
shipright@aladdin.co.uk
-----------------------------------------------------------

In article <52q3f3$t2d@everest.iserv.net> P Barnes wrote:
>>Your higher fuel consumption in winter is not necessarily caused by lower 
>>engine efficiency but by higher aerodynamic drag on the car. If the air
> is 
>>say 30 degrees C colder in the winter it will be about 10% denser. This
> means
>>10% higher drag that must be compensated by higher power output from
>>the engine.
(snip)
Has anyone considered the fact that the gasoline you buy in the winter is not the 
same as the gasoline that you buy in the summer?  Winter gas is now oxygenated, 
providing extra oxygen atoms for the gasoline to burn cleaner (particularly during 
cold startup and warmup, a serious source of polluting emissions from automobiles 
during the winter).  The extra oxygen helps the fuel burn cleaner, but also carries a 
lower volumetric energy density than the summer gasoline. Use oxygenated gasoline 
during the summer and watch your gas mileage drop.
-----------------------------
Will Gardner
gardnerw@gnn.com
-----------------------------

Hi,
I'd like any advice I can get on applying for a scholarship that is 
sponsored by the ASQC (society for quality control).  I have NO idea as 
to what I should emphasize or de-emphasize or even what to include/leave 
out when applying.  If anyone out there knows much about this sort of 
thing (I've never applied for a scholarship in my life), I'd appreciate 
all advice that I can get.
I haven't gotten the application yet, but here is a brief summary of my 
qualifications.
Maths major/comp.sci minor.  (Junior)
Nearly finished all required maths courses (including probability/math 
stats)
Participated in COMAP math modelling competition (received meritorious 
recognition for paper)
Passed SOA 100,110 exams.
Many extra-curricular activities.
Worked for 7 months on Satellite Communications software, which included 
writing a program that analyzed bit-error rates for my (former) 
company's SATCOM system's over-seas transmissions were evaluated.  Also 
worked on other less math-oriented areas of SATCOM software.
Currently work for John Deere in applications development.  Work with 
Mech Eng's.  (gear design)  Implement new gear-design methods in a 
software package, which is used to design all our gears here (in 
drive-train, anyway).  Recently worked on a project to reduce scrap rate 
by improving heat-treatment of gears (they estimate this to be a 
substantially large improvement in scrap-rates)
That's about all of it.
I'd apreciate any suggestions,
-Jesse

	I have a question for all the Mechanical engineers out there that
did not graduate with a spectacular gpa. How did you get into the ME
field? I have been looking for a job since before I graduated in december
95 from New Mexico State University with a BS. All I seem to be getting is
"we are looking for someone with more experience in ____". I specifically
kept my class work from concentrating on one subject (ie. fluids, aero,
heat transfer, ect). I am begining to think that I should have
specialized. 
	Another complaint (sorry this is turning into a bitch session) is
most companies don't want anything to do with you if you don't have at
least a 3.2/4.0 GPA. Which brings me back to the original question, How
does one get a Mechanical Engineering job if you don't have a spectacular
GPA? I would rather not be a high velocity food process engineer for
McDonalds.
Richard Murphy
 -- 
*************************************************************************
*   		      	The Original Hippy on Acca                      *
*			     Rich Murphy BSME				*
*		hippy@acca.nmsu.edu	hippy@corholio.NMSU.EDU		*
*				rmurphy@nmsu.edu			*
*									*
*	The opinions expressed are mine, If I was employed they would	*
*	    STILL be mine. But if anyone would like to change the 	*
*	       employment part I would gladly listen to them.		*
*									*
*************************************************************************

MIMOSA  wrote in article
<3247c029.2957491@server.cntfl.com>...
> On Tue, 17 Sep 1996 23:01:19 +0100, Brett Wing
>  wrote:
> 
> I'm a civil engineering student trying to decide on electives to take.
> Any suggestions on what might be most useful later on??
> 
I'm a Structural Graduate, with an Environmental Masters Degree. I was
wondering, seeing as we're on the topic of which Civil's are more in
demand, who think's this is a good combination? 
Simon McFadden, Ireland.

Can someone please tell me a way to calculate the mechanical shock
experienced by an electronics device weighing 50 pounds falling from a
height of 15 feet?  What is the formula for doing such computations?  I
work in areas of damage assessment.  Often electromechanical assemblies
are rated for environmental parameters.  Sometimes shock (in G's) is such
a parameter.  I am looking for a way to calculate shock in G's as in the
example above.
Thanks in advance for your help.
GGladden@aol.com

In article <3250631A.468A@julian.uwo.ca>, Paul Kurowski
 wrote:
>Actually, my results indicated divergent displacement under point load, not 
>zero stress or infinite displacement.
>
>
>Paul Kurowski
Mea culpa, Paul. I misunderstood your post. Sorry for the kipper.
Christopher Wright P.E.    |"They couldn't hit an elephant from
chrisw@skypoint.com        | this distance"   (last words of Gen.
___________________________| John Sedgwick, Spotsylvania 1864)
http://www.skypoint.com/subscribers/chrisw

How do the servos in a hard disk drive react to power surges/sags,
brownouts and blackouts?  Do these conditions degrade the life of the
drive or cause mechanical failures?
Thanks for your help.
GGladden@aol.com

In article <32509096.87F@weh.rwth-aachen.de> HW Raedt  writes:
>   > What kind of bearings would be worth a look at for this application?
>   > The emphasis has to be on reduced cost and they have to be mass
>   > producible.
>   Harddisk bearings, rpm ~ 3000 to 6000 rpm, definitely mass producible
These are mostly ball bearings - I don't think there is anything particularly
unsual about them.  Some VCRs have used special oil film bearings for the
head drum, however.
--- sam

In article <01bbaf04$213a00c0$6ba5b9ce@default>, "John Lawrence"
 wrote:
>I am searching for information regarding the assessment of wind damage to
>water towers.
You can pick up racking deformation by measuring across opposite corners
of symetric bays. There'll always be some difference due to fab
tolerances, but it's severe and specific to wind direction if there's
significant damage. Check for paint flaking at panel points, too. The real
tip-off is when you find it lying on one side pointing downwind. Look for
that first. ;->
Christopher Wright P.E.    |"They couldn't hit an elephant from
chrisw@skypoint.com        | this distance"   (last words of Gen.
___________________________| John Sedgwick, Spotsylvania 1864)
http://www.skypoint.com/subscribers/chrisw