mar21aa@vmsa.technion.ac.il (03/31/90)
This is for a friend that does not have net access. I do not read the mac list
myself, so please responed directly by E-mail: What program converts GIF pics
for the MAC, and where can I get it (assumenig it's public-domain) ?
Nathan Srebro
Haifa, Israel
MAR21AA @ Technion.BITNET
#! rnews 1317
Relay-Version: VMS News - V5.8 02/03/89 VAX/VMS V5.2; site vmsa.technion.ac.il
Path: vmsa.technion.ac.il!Path-Lost
Newsgroups: sci.military
Subject: Re: Trials?
Message-ID: <13932@cbnews.ATT.COM>
From: livesey@solntze.Eng.Sun.COM (Jon Livesey)
Date: 13 Feb 90 03:19:38 GMT
Sender: military@cbnews.ATT.COM
References: <13548@cbnews.ATT.COM> <13892@cbnews.ATT.COM>
Organization: Sun Microsystems, Mountain View
Approved: military@att.att.com
Lines: 28
From: livesey@solntze.Eng.Sun.COM (Jon Livesey)
In article <13892@cbnews.ATT.COM> ron@hpfcso.hp.com (Ron Miller) writes:
>
>
>From: ron@hpfcso.hp.com (Ron Miller)
>
>Re: Trials & suicide orders
>
>
>I had a Commanding Officer who was under the impression that peacetime
>and wartime standards were different.
>
>One of his favorite phrases was, " If this was wartime, I'd shoot you."
At Aldershot, many years ago, there was a Drill Sergeant whose
favourite form of abuse for future officers was "If I were your father,
I'd shoot meself".
One day, he was in the process of abusing a particularly idle officer
in training, who happened to be the Prince of Wales (later the Duke
of Windsor).
"If I was your father", he began, and then realising that what he was
about to suggest was very likely treason, he trailed off into "I'd,
I'd, I'd...... h'abdicate!".
jon.
#! rnews 7700
Relay-Version: VMS News - V5.8 02/03/89 VAX/VMS V5.2; site vmsa.technion.ac.il
Path: vmsa.technion.ac.il!Path-Lost
Newsgroups: sci.environment
Subject: EMP, its cause and effects
Message-ID: <1535@argus.UUCP>
From: ken@argus.UUCP (Kenneth Ng)
Date: 18 Feb 90 02:36:44 GMT
Organization: NJ Instit. of Tech: TEIES Project
Lines: 135
Sorry the message I ment this to be replied to had expired on this machine.
someone said that EMP is really caused by the effect of the electrons
passing through the EArth's magnetic field, or something like that.
Unfortunately I can no longer read it, so I'm going by memory. I looked
up the information and am quoting some below.
The following text is taken from "The Effects of Nuclear Weapons", by
Samuel Glasstone and Philip J. Dolan. The one I have was published
in 1977, it was prepared and published by the Department of Defense,
and the Department of Energy. To date it is the most comprehensive
book I've found to date.
Chapter 11.05
The instantaneous gamma rays emitted in the nuclear reactions and
thos produced by neutron interactions with weapon residues or the
surrounding medium are basically responsible for the processes that
give rise to EMP from bursts in the lower atmosphere. The gamma rays
interact with air molecules and atoms, mainly by the Compton
effect, and produce an ionized region surrounding the burst point.
In EMP studies this is called the "deposition region". The negatively
charged electrons move outward faster than the much heavier positively
chargd ions and as a result there is initially a separation of charges.
This separation of charges produces an electric field which can attain
its maximum value in about 10 E-8 seconds
Chapter 11.06
If the explosion occurrd in a perfectly homogeneous atmosphere and
the gamma rays were emitted uniformly in all directions, the electric
field would be radial and spherically symmetric. i.e. it would
have the same strength in all directions outward from the center.
There would then be no electromagnetic energy radiated from the
ionized deposition region. In practice, however, such an ideal
situation does not exist; there is inevitably some condition, such as
differencees in air density at different levels, proximity of the
earth's surface, the nonuniform configuration of the exploding
weapon, or even variations in the water vapor content of the air, that
will interfr with the symmetry of the ionized region. If the burst
occurs at or near the earth's surface, the departur from the
spherical symmetry will clearly be considerable. In all these
circumstances, there is a net vertical electron current generated
within the ionized deposition region. The time varying current results
in the emission of a short pulse of electromagnetic radiation which
is strongest in directions perpendicular to the current; this is the
EMP. In a high-altitude explosion, the EMP arises in a somewhat
differnt manner, as will be seen shortly.
Chapter 11.13
If the nuclear burst is at an altitude above about 19 miles, the gamma
rays moving in an upward direction will enter an atmosphere where the
air density is so low that the rays travel great distances before being
absorbed. On the other hand, the gamma rays emitted from the explosion
in a generally downard direction will encounter a region where the
atmospheric density is increasing. These gamma rays will interact with
the air molecules and atoms to form the deposition region for the EMP.
This roughly circular region may be up to 50 miles thick in the center,
tapering toward the edge, with a mean altitude of about 25 to 30 miles.
It extends horizontally for great distances which increases with the
energy yield and the height of the burst point.
Chapter 11.14
In the deposition region the gamma rays produce Compton electrons by
interactions in the air; these elctrons are deflected by the earth's
magnetic field and are forced to undergo a turning motion about the
field lines. This motion causes the electrons to be subjected to a
radial acceleration which results, by a complex mechanism, in the
generation of an EMP that moves down toward the earth. The pulse
rises to a peak and then decreases, both taking plac more rapidly
than for a surface burst; as a result more of the electromagnetic
energy appears in the higher frequency range. The strength of the
electric field observed at the surface from a high altitude explosion
is from one tenth to a hundredth of the field within the source
region from a surface blast.
Theory of the EMP
Development of the radial electric field
Chapter 11.60
The energies of teh prompt gamma rays accompanying a nuclear explosion
are such that, in air, Compton scattering is the dominant photon
interaction. The scattered photon frequently retains sufficient energy
to permit it to repeat the Compton process. Although scattering is
somewhat random, the free electrons produced (and the scattered
photons) tend, on the average, to travel in the radial direction
away from the burst point. The net movemnt of the electrons constitutes
an electron current, reffered to as the Compton current. The prompt
gamma-ray pulse increases rapidly to a peak value in about 10E-8
second or so, and the Compton current varies with time in a similar
manner.
11.61
When the electrons are driven radially outward by the flux of gamma
rays, the atoms and molecules from which they have been removed,
i.e. the positive ions, travel outward more slowly. This results
in a partial seperation of charges and a radial electric field.
The lower energy (secondary) electrons generated by collisions of the
Compton electrons are then driven back by the field toward the
positive charges. Consequently, a reverse electron current is produced
and it increases as the field strength increases. This is called the
"conduction current" because, for a given field strength, its
magnitude is determined by the electrical conductivity of the ionized
medium. The conductivity depends on the extend of ionization which
itself results from the Compton effect; hence the conductivity of the
medium will increase as the Compton current increaeses. Thus, as the
radial field grows in strength so also does the conduction current.
The conduction current flows in such a direction as to oppose this
electric field; hence at a certain time, the field will cease to
increase. The electric field is then said to be "saturated". At
points near the burst, the radial electric field reaches saturation
sooner and is somewhat stronger than at points farther away.
11.73
The peak electric field (and its amplitude) at the earth's surface
from a high altitude burst will depend on the explosion yield,
the height of the burst, the location of the observer, ad the
orientation with respect to the geomagnetic field. [edit]
The spatial distribution of the EMP elctric field depends on the
geomagnetic field and so varies with the latitude; the results
in the figures apply generally for ground zero between about 30
and 60 degrees north latitude. South of the geomagnetic equator the
directions indicating magnetic north and east in the figure would become
south and west respectively.
<the rest is deleted because I'm tired of typing>
To summarize: I was correct in stating the actual mechanism concerning
how EMP is generated. You are correct in stating that Earth's magnetic
field affects its distribution. The compton electrons I suspect are
not affected by the magnetic field, but the secondary electrons are.
--
Kenneth Ng: Post office: NJIT - CCCC, Newark New Jersey 07102
uucp !andromeda!galaxy!argus!ken *** NOT ken@bellcore.uucp ***
bitnet(prefered) ken@orion.bitnet or ken@orion.njit.edu
#! rnews 7637
Relay-Version: VMS News - V5.8 02/03/89 VAX/VMS V5.2; site vmsa.technion.ac.il
Path: vmsa.technion.ac.il!Path-Lost
Newsgroups: sci.space
Subject: Re: Japan and the Moon in 2010?
Message-ID: <2031@gmdzi.UUCP>
From: thg@gmdzi.UUCP (Thomas Hagemann)
Date: 16 Feb 90 16:27:24 GMT
References: <13712@phoenix.Princeton.EDU>
Organization: GMD, Sankt Augustin, F. R. Germany
Lines: 149
>
> A short news item in the "Briefings" column in the 2 February 1990 issue
> of SCIENCE (p. 530) notes
>
> "Shimizu Corporation, the world's largest construction company, has
> assigned 25 engineers to develop concepts for a human-occupied lunar
> base."
>
The Japan Economic Journal notes on Sept. 30, 1989, page 4
Construction firms launch space projects
Planet Earth holds no bounds for Japan's major construction companies.
Over the past two years, several construction-engineering groups have set up
special space project teams or announced designs for ambitious orbital or
lunar projects that might be biult next century.
They include plans for exotic moon resorts and orbiting "space hotels" for
idle rich who want an "out of this world" experience.
The construction industry's real interest in space began two years ago when
Shimizu Corp. became the first Japanese construction firm to establish a
space project office.
Since then, with an eye on lucrative contracts in the next few decades, both
Shimizu and Ohbayashi Corp. have explored the idea of moon bases, at first
unmanned, that could be constructed after 2010.
Space stations
Further, Mitsubishi Heavy Industries Ltd., Japan's largest aerospace contractor,
is studying the concept of a Japanese space station, set to be in orbit about
10 years after the late 1990s start-up of the U.S.-led Freedom station.
Toshiba Corp. and Hitachi Ltd. also are doing space station investigations. In
their preliminary plans, robots would be deployed to do much of the assembly
and construction work.
Both the lunar base and space station proposals are among several on the long-
term drawing boards of the National Space Development Agency of Japan (NASDA).
Besides NASDA, researchers at the government's Institute of Space and
Astronautical Science (ISAS) and at the National Aerospace Laboratory (NAL)
are also investigating moon projects.
However, because of budget constraints, NASDA and NAL are carrying out
fundamental research on lunar bases with the understanding that such bases
would be built and maintained by multinational teams.
While the Ministry of Finance has yet to authorize such plans, the construction
companies believe they will have opportunities to play lerger roles in the
nation's space program.
So far their roles have been limited to construction work through consortia
for the new Yoshinobu launch site at the Tanegashima Space Center in Kagoshima
Prefecture and other facilities.
The Yoshinobu site will be used from about 1993 for launching NASDA's large
H-II vehicle, which is now experiencing serious development delays.
Space hotels and moon bases
Japanese space proposals run the gamut, from mundane studies of basic life-
support systems to so-called space hotels.
Shimizu, for instance, recently announced a proposal for a "space hotel" that
might be constructed in orbit around Earth after 2010.
Shimizu engineers say that the advent of transatmospheric spaceplanes early
next century might make such a space hotel feasible. Projected prices for a
five-night stay would start around $200,000, Shimizu engineers say.
Over at Ohbayashi, engineers have released a comprehensive study for a "Lunar
City" resort on the moon, with a target date of around 2050.
Takao Saito, manager of Ohbayashi's space project department, says the proposal
would include a helical tower - featuring a hotel and communications
equipment, with a large dome at its base.
Plans call for an earth-like environment to be enclosed within the dome.
Research centers, offices, life-support and sport facilities and factories
would be housed in separate buildings near the dome.
Ohbayashi has conducted preliminary studies on a "controlled ecological life
support system" for a lunar base together with the ISAS's Professor Kyoichi
Kuriki.
For example, it is testing a water treatment and purification system that
might be used for a lunar base.
Another construction firm, Takenaka Corp., syas it is a toilet and shower for
use in microgravity space conditions.
Catapulting rockets
The large construction companies are also interested in developing space-
related equipment for use on the Earth.
For example, Hazama-Gumi Ltd. recently did a feasibility study on ways to
"catapult" rockets or space shuttles from a 2,000-meter-deep shaft.
The idea is to use compressed air and linear motors to give an initial boost
to rockets before they leave the ground. Hazama's concept is based on its
mineshaft drilling technology, a company spokesman said.
Ignition of rocket engines would occur when the vehicle approaches Mach 1,
according to Hazama.
The company says the system would cost about $2.5 billion more than a standard
launch site. However, it would enable the launch vehicle to carry a heavier
payload because less rocket fuel would be needed.
Hazama's plan follows an above-ground "rocket catapult system" idea developed
by Taisei Corp. That Tokyo-based company suggests that shuttles be boosted into
orbit using a 2,100-meter-high inclined ramp featuring linear motors that
would provide an extra kick to the vehicle. The ramp, similar to a roller
coaster, would have a 3,650-meter-long base.
Just a few years ago, the construction companies had limited interest in space
research. They were members of the Space Activities Promotion Council of
Keidanren (the Federation of Economic Organizations) and did construction
work at launch sites and space centers.
Construction engineers and architects over the age of 35 doubt they will see
any of the projects completed before they retire.
But they say they want to pass on exciting tasks to younger colleagues while
urging them to set their sights high.
[by Neil Davis, special to the Japan Economic Journal]
---------------------------------------------------
Thats the Japanese spirit!
If a manager in a german construction company would propose to set up a planning
team for space bases in the year 2050, he could look for another job.
Thomas @ GMD, Sankt Augustin, Germany
thg@gmdzi.uucp
From vn Tue Feb 13 17:20:11 1990
Subject: Re: The Japanese language a handicap ?
Newsgroups: soc.culture.japan
References: <6542@uhccux.uhcc.hawaii.edu>
From article <6542@uhccux.uhcc.hawaii.edu>, by jmu@uhccux.uhcc.hawaii.edu (James
Unger):
>
> A lot of people believe Tunoda Tadanobu's "Japanese brain" thesis, judging
> from sales of his books. I certainly wouldn't take that to mean that his
> theories are worth anything, would you?
Just for reference:
%A Tadanobu Tsunoda
%T The Japanese Brain - Uniqueness and Universality
%I The Taishukan Publishing Company
%D 1985
%O ISBN 4-469-21129-X
Thomas @ GMD, Germany
From vn Tue Feb 13 17:33:00 1990
Subject: Re: Japan is 5 years behind the U.S. in software
Newsgroups: soc.culture.japan
References: <13773@phoenix.Princeton.EDU>
From article <13773@phoenix.Princeton.EDU>, by hehuang@phoenix.Princeton.EDU (Br
other_of_Liberty):
>
> BTW, there are some very good GO professionals in USA, as far as I know, and
> they are NOT TOO bad compared with Japanese players.
>
The american GO professionals are mostly of korean ancestry, except for 2
(two) living in Japan: James Kerwin at Kansai Kiin, around 2-Dan, and
Michael Redmond at Nihon Kiin, 5- or 6-Dan.
Thomas @ GMD, Germany
#! rnews 1097
Relay-Version: VMS News - V5.8 02/03/89 VAX/VMS V5.2; site vmsa.technion.ac.il
Path: vmsa.technion.ac.il!Path-Lost
Newsgroups: comp.dcom.lans
Subject: Re: Cable Taps/No Cable Taps.
Message-ID: <2510@dlvax2.datlog.co.uk>
From: gjack@datlog.co.uk ( Graham Jack )
Date: 16 Feb 90 09:01:40 GMT
References: <1043@prlhp1.prl.philips.co.uk> <1603@ariel.unm.edu>
Organization: Data Logic Ltd, Queens House, Greenhill Way, Harrow, London.
Keywords: AUI ethernet cable transceiver
Lines: 21
dd@ariel.unm.edu (dd) writes:
>Martin Holland writes:
>>This may be a naive question but is it permissable to connect one ethernet
>>AUI cable from an ethernet device into another instead of connecting each
>>to a cable tap and have these tapped into an ethernet cable.
>>I want to plug a bridge into a repeater. ......