https://github.com/GyanD/codexffmpeg/releases/tag/2023-03-05-git-912ac82a3c

RSID: <<2024-07-18T23:31Z MFSK-32 @ 9265000+1500>>
 

Welcome to program 362 of Shortwave Radiogram.

I'm Kim Andrew Elliott in Arlington, Virginia USA.

Here is the lineup for today's program, in MFSK modes as noted:

  1:43 MFSK32: Program preview (now)
  3:07 MFSK32: Device pulls drinking water from arid air
  6:34 MFSK64: Four categories of cubesat propulsion systems*
12:00 MFSK64: This week's images*
28:21 MFSK32: Closing announcements

* with image(s)



Please send reception reports to radiogram@verizon.net

And visit http://swradiogram.net

We're on X/Twitter now: @SWRadiogram




From New Atlas:

Harvester pulls 1.5 gallons of drinking water from arid air per
day

By Michael Irving
July 04, 2024

It's an unfortunate irony that while many regions struggle to
find enough water, there's trillions of liters of the stuff
floating around in the air everywhere. A new water harvester
design from MIT can pull enough fresh water out of the air to
meet the daily needs of several people.

Water harvesters are usually made up of adsorbent materials,
meaning they collect water on their surfaces. To maximize the
surface area exposed to the air, this new device is made up of a
series of vertical fins spaced 2 mm (0.08 in) apart. These fins
are made up of copper sheets, sandwiched in copper foams and then
coated with a specialized zeolite material which is often used
for water adsorption.

After an hour the fins are saturated with water, so the copper
sheets are heated up to release it. If this cycle is performed 24
times per day, in air with 30% humidity (classed as arid), the
team estimates the harvester can produce up to 1.3 L (0.3 gal) of
drinkable water per day per liter of the adsorbent coating used.
Scaled up, that's 5.8 L (1.5 gal) per kilogram (2.2 lb) of
material used per day, which is enough to satisfy several
people's daily water needs.

While there's no shortage of other water harvesters in the works,
this one has a few advantages. For one, it collects more water
than most – some can only fetch 100 ml (1.5 oz) of water per kg
of material. A Johns Hopkins design sounds particularly
impressive, harvesting 8.66 L (2.3 gal) per day per kg of
material, but these tests were conducted at 70% humidity. The new
design can also work consistently throughout the day and night,
where others collect their water overnight and release it in the
morning.

The potential downside is that this system requires energy to
release the water – the base of the device needs to reach 184 °C
(363 °F) to wring it out. But the team says the device can tap
into waste energy or heat from other systems, like buildings or
vehicles.

The research was published in the journal ACS Energy Letters.

https://newatlas.com/technology/water-harvester-arid-air-mit/
 

Shortwave Radiogram now changes to MFSK64 ...


 

RSID: <<2024-07-18T23:36Z MFSK-64 @ 9265000+1500>>


This is Shortwave Radiogram in MFSK64

Please send your reception report to radiogram@verizon.net
 

From Universe Today via Phys.org:


CubeSat propulsion technologies are taking off

by Andy Tomaswick
July 8, 2024

CubeSats are becoming ever more popular, with about 2,400 total
launched so far. However, the small size limits their options for
fundamental space exploration technologies, including propulsion.
They become even more critical when mission planners design
missions that require them to travel to other planets or even
asteroids.

A team from Khalifa University of Science and Technology in Abu
Dhabi recently released a review in Aerospace of the different
CubeSat propulsion technologies currently available—let's look at
their advantages and disadvantages.

The paper breaks propulsion systems into four categories:
Chemical, Kinetic, Electrical, and "Propellant-less." Chemical
systems are the traditional rockets most people think of when
launching satellites—they burn chemicals together and expel gas
created by the fire to produce thrust. Kinetic systems use things
like cold gas, where instead of reacting two chemicals together,
they simply push gas molecules out to propel themselves in the
opposite direction.

Electrical systems are similar to kinetic systems but use an
electrical system, such as a Hall Effect thruster, to heat the
propellant before it is expelled. Lastly, propulsion-less
technologies don't have any active component and instead,
passively use the forces from space itself to move about. The
most common example of this is solar sails.

Let's start with chemical propulsion. This is probably the least
helpful setup for CubeSats, as the material requirements for
handling small explosions make the supporting infrastructure too
bulky and heavy to fit into a traditional CubeSat package. Even
though some miniaturized systems that could fit in a CubeSat
framework have been developed, chemical propellant systems likely
won't take off soon.

Kinetic systems are much more common for CubeSats, and the paper
breaks them down into two major categories: Cold Gas and
Resistojet. In the past, we've reported about systems that use
everything from ammonia to water as kinetic propellants, which
would fall under the category Cold Gas. If the gas is heated
slightly before release, the system becomes a Resistojet
configuration. While the heating is nowhere near the level of
explosions used in chemical rockets, it still increases the force
of the propellant exiting out the thruster's nozzle.

Electric propulsion is similar in many ways to Kinetic
propulsion, but it uses electric energy to heat its propellants
before discharge. The paper breaks these technologies into three
major categories: Electrothermal discharge, Electrostatic, and
Electromagnetic. Electrothermal discharge systems are similar to
arcjets, though no system small enough to fit into a CubeSat form
factor has yet been developed that can provide the power needed
for such a system.

Electrospray systems use electrical forces rather than heating to
accelerate charged particles used as propellants. Charged
particles are accelerated through a magnetic field created by the
propulsion system and forced through the thruster's nozzle at
high speed. Electromagnetic systems operate similarly by using an
arc to ionize propellant, which is then pushed out by the
magnetic field that is formed around the ionized material.

Overall, electric systems are becoming more common on CubeSats.
Still, their material requirements typically demand
high-precision machining and other advanced technologies that
make them trickier to develop than simple kinetic systems.

Non-propellant systems have become more widespread with the
successful test of Lightsail, the Planetary Society's solar sail
technology demonstrator. However, other propellant-less
technologies, such as tethers or a magnetic sail that powers
itself via the magnetic fields floating around the solar system.

At the same time, many of these systems remain in the conceptual
phase; their ability to provide potentially limitless thrust
appeals to CubeSat designers with longer-term missions in mind.
However, they are again limited by material development and size
constraints, as large structures are required for many of them,
and it is challenging to pack those into the confines of a
CubeSat.

With all the development going on in the world of CubeSats, more
ideas will undoubtedly be mooted in the future. With launch costs
coming down, more industries and non-governmental organizations
will be interested in how the platform could help them. But no
matter where CubeSats end up being used, they will have to trust
their propulsion systems to get there.

https://phys.org/news/2024-07-cubesat-propulsion-technologies.html


Image: NASA illustration of cubesat propulsion ...

 

Sending Pic:194x148C;




 

This is Shortwave Radiogram in MFSK64

Please send your reception report to radiogram@verizon.net
 

This week's images ...
 

A person poses in front of a telephone box during a visit to
Mayfield Lavender Farm in Carshalton, southern England.
https://tinyurl.com/2yqtubzh ...


Sending Pic:203x133C;








The Macy’s 4th of July fireworks form a backdrop to the Manhattan
skyline. https://tinyurl.com/2y3khkx7 ...

Sending Pic:116x228C;








A Bengal tiger rests in a shaded area in a zoo in Konya, Turkey,
June 24. https://tinyurl.com/2y7pmsnq ...

Sending Pic:190x152C;








An air tanker drops fire retardant over a house during the Toll
Fire in Calistoga, California, July 2.
https://tinyurl.com/2y7pmsnq ...

Sending Pic:201x139C;
 

A rare blue-colored tree frog holds on to a leaf in Bursa,
Turkey, June 28. https://tinyurl.com/2y7pmsnq ...

Sending Pic:158x203C;







Cairns (rock stacks) in the sunset at Kring Point State Park, New
York, overlooking the St. Lawrence River, July 9.
https://tinyurl.com/2xjzc3fy ...

Sending Pic:154x198C;








An ancient cellar at Edge of the Cedars State Park in Utah, July
2. https://tinyurl.com/2a78rj9k ...

Sending Pic:156x193C;








Berries on a Guelder Rose tree at the Lewes Urban Arboretum in
England. https://tinyurl.com/2dac6fvd ...

Sending Pic:148x201C;







Our painting of the week is by Kate Jarvik Birch (American),
gouache on paper. https://tinyurl.com/23svrquj ...

Sending Pic:194x194C;








Shortwave Radiogram returns to MFSK32 ...






 

RSID: <<2024-07-18T23:58Z MFSK-32 @ 9265000+1500>>
 

This is Shortwave Radiogram in MFSK32 ...


Shortwave Radiogram is transmitted by:

WRMI, Radio Miami International, wrmi.net

and

WINB Shortwave, winb.com


Please send reception reports to radiogram@verizon.net

And visit http://swradiogram.net

Twitter: @SWRadiogram or twitter.com/swradiogram

I'm Kim Elliott. Please join us for the next Shortwave
Radiogram.