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Friederike Sontag

CFC Replacements Intensify Climate Concerns - 0 views

www.washingtonpost.com/...AR2009071901817.html

global warming_chemicals

shared by Friederike Sontag on 21 Jul 09 - Cached
  • Friederike Sontag on 21 Jul 09
     
    "But researchers say what's good for ozone is bad for climate change. In the atmosphere, these replacement chemicals [replacements for CFCs] act like "super" greenhouse gases, with a heat-trapping power that can be 4,470 times that of carbon dioxide." Havent't heard of this before...
LeopoldS

Darpa: Heat + Energy = Brains. Now Make Us Some. | Danger Room | Wired.com - 0 views

www.wired.com/...energy-brains-now-make-us-some

AI INF brain BMI BIO defence

shared by LeopoldS on 13 May 09 - Cached
  • LeopoldS on 13 May 09
     
    good luck!!
ESA ACT

Almost Art - 0 views

prl.aps.org/4

Fun PHY thermal

shared by ESA ACT on 24 Apr 09 - Cached
  • ESA ACT on 24 Apr 09
     
    Very nice simulation of a heated liquid.
ESA ACT

Scientists Use Sunlight to Make Fuel From CO2 - 0 views

www.wired.com/...S2P

NRG technology

shared by ESA ACT on 24 Apr 09 - Cached
  • ESA ACT on 24 Apr 09
     
    Sandia researcher Rich Diver checks out the solar furnace which will be the initial source of concentrated solar heat for converting carbon dioxide to fuel. Eventually parabolic dishes will provide the thermal energy. Photo: Randy Montoya / Sandia Nati
Thijs Versloot

Ultrafast collisional ion heating by electrostatic shocks - 0 views

www.nature.com/...ncomms9905.html

shared by Thijs Versloot on 23 Nov 15 - No Cached
jcunha liked it
  • Thijs Versloot on 23 Nov 15
     
    Collisionless electrostatic shocks (CES) are the dominant process in heating a plasma when using high power lasers. It turns out that ion-ion collisions actually only play a small role. The ability to create small regions of very high ion energy density on time scales shorter than that of hydrodynamic expansion will be of interest in attempts to understand the processes involved in inertial confinement fusion.
LeopoldS

Increased core body temperature in astronauts during long-duration space missions | Sci... - 0 views

www.nature.com/...s41598-017-15560-w

shared by LeopoldS on 04 Jan 18 - No Cached
  • LeopoldS on 04 Jan 18
     
    38 degree core body temp in microgravity stabilised after 2 months - due to reduced conv. heat transfer+evaporation https://www.nature.com/articles/s41598-017-15560-w
  • marliesarnhof on 05 Jan 18
     
    so that's hypopyrexia (augmented concentrations of interleukin-1 receptor antagonist) AND hypothermia (convection/evaportation)? what puzzles me is that temperatures take so long to return to baseline after astronauts return to earth.
LeopoldS

[1305.3913] Indication of anomalous heat energy production in a reactor device - 5 views

arxiv.org/1305.3913

shared by LeopoldS on 23 May 13 - No Cached
  • LeopoldS on 23 May 13
     
    looks like some backwind for all the cold fusion believers ...
  • ...1 more comment...
  • johannessimon81 on 24 May 13
     
    Actually Sante and me just reviewed their paper. Although (some of) the scientists in the paper seem to have good track records their experimental techniques are by far not the best to determine the excess amount of energy produced. Even though their methods may introduce fairly large errors they would not be able to negate the cited power output - so they either are super-sloppy (i.e. they lie) or there is TRULY new physics involved... A big problem is that they are basically verifying somebody else's experiment - however because this guy is paranoid he does not tell them exactly what he did. In fact they went to his lab and used a setup that HE put together. All they do is do a measurement on it and it seems like they try to be thorough. There is quite a chance that the guy behind it all (Rossi) is setting them up - personally I would think >95%. However, the implications of this being new physics are so big that I think further research should be conducted.
  • LeopoldS on 24 May 13
     
    I just answered something very similar to Franco, except the conclusions: I don't think that there is a good reason for us or anybody else in ESA to get involved at this stage.
  • johannessimon81 on 24 May 13
     
    I agree - if this device would work it there would be other interest groups (like the energy sector) with a much more concrete stake in the technology.
jcunha

New method uses heat flow to levitate variety of objects - 1 views

phys.org/...2-method-levitate-variety.html

technology science PHY microgravity

shared by jcunha on 16 Feb 17 - No Cached
  • jcunha on 16 Feb 17
     
    Normally we associate levitation of objects to superconducting materials. Here a new technique is shown where levitation of a whole new range of materials is shown. "The large temperature gradient leads to a force that balances gravity and results in stable levitation," said Fung, the study's lead author. "We managed to quantify the thermophoretic force and found reasonable agreement with what is predicted by theory. This will allow us to explore the possibilities of levitating different types of objects." Paper at http://aip.scitation.org/doi/10.1063/1.4974489 New microgravity experiments possibility?
  • LeopoldS on 01 Mar 17
     
    not really I fear .... "Typical sizes of the trapped particles are between 10 μm and 1 mm at a pressure between 1 and 10 Torr. The trapping stability is provided radially by the increasing temperature field and vertically by the transition from the free molecule to hydrodynamic behavior of thermophoresis as the particles ascend."
  • jcunha on 06 Mar 17
     
    Might still be OK micro to mm sized experiments. The technique seems to be reliable and cheap enough to compete with other types of microgravity approaches - more research needed to define boundaries of course.
Lionel Jacques

Exotic explanation for Pioneer anomaly ruled out - 1 views

physicsworld.com/...-for-pioneer-anomaly-ruled-out

Space Trajectory Pioneer

shared by Lionel Jacques on 18 Apr 12 - No Cached
  • Lionel Jacques on 18 Apr 12
     
    "Given that for both craft electricity is supplied by a radioisotope thermoelectric generator (RTGs) powered by the heat given off by the radioactive decay of plutonium - an energy source that decays exponentially with time - Turyshev and others suggested that the extra acceleration could be caused by thermal radiation being emitted from the craft in a preferred direction. "
LeopoldS

Nuclear powered drones? - 2 views

www.fas.org/...sand-uav.pdf

NPS nuclear RTG NRG

shared by LeopoldS on 02 Apr 12 - No Cached
  • LeopoldS on 02 Apr 12
     
    Not explicit but smells like RTGs
  • dejanpetkow on 03 Apr 12
     
    "The effort contrasted and compared eight heat sources technologies, three power conversion, two dual cycle propulsion system configurations, and a single electrical power generation scheme." Yes, it's about RTGs, at least partially.
  • Ma Ru on 03 Apr 12
     
    The quote "it was disappointing to all that the political realities would not allow use of the results" may refer to RTGs too :-)
santecarloni

Graphene Battery Turns Ambient Heat Into Electric Current - Technology Review - 0 views

www.technologyreview.com/...27625

battery technology Science

shared by santecarloni on 05 Mar 12 - No Cached
  • santecarloni on 05 Mar 12
     
    "Physicists have built a graphene battery that harvests energy from the thermal movement of ions in solution." Can it actually work?
Thijs Versloot

Underground oceans - 1 views

phys.org/...014-01-ocean-beneath-feet.html

science

shared by Thijs Versloot on 29 Jan 14 - No Cached
  • Thijs Versloot on 29 Jan 14
     
    Interesting report on water transport in deep see fault lines. Subduction can suck huge quantities of water of water underground where friction and pressure heat it up causing the mantle to partly melt which leads to volcanic activities around the fault zones. Not all the water would make it back up, leading to the possibility that there might be large quantities of water stored within the earths crust.
Thijs Versloot

Self-fueled robotic grass mower #EcoMow - 2 views

phys.org/...robotic-ecomow-grass-fuel.html

robotics technology fun

shared by Thijs Versloot on 18 Feb 14 - No Cached
  • Thijs Versloot on 18 Feb 14
     
    The grass mower uses the cut grass as fuel, but can also turn the grass into dried pellets for later use, for example for heating etc.
Thijs Versloot

Word of the day - thermoelectric magnetohydrodynamic flow - 1 views

physics.aps.org/st8

fusion MHD

shared by Thijs Versloot on 10 Dec 13 - No Cached
  • Thijs Versloot on 10 Dec 13
     
    Heat and a magnetic field cause the liquid lithium to swirl rapidly, an effect that could be useful in fusion reactors. With a nice video http://physics.aps.org/assets/eab7d11d-20cd-4c37-ab2c-313729ad8422/video-v1.mp4
Thijs Versloot

Forget 3D printing, here is solar printing - 3 views

www.sciencedaily.com/...140403132353.htm

solar energy

shared by Thijs Versloot on 04 Apr 14 - No Cached
LeopoldS liked it
  • Thijs Versloot on 04 Apr 14
     
    The work is based on the use of a "continuous flow" microreactor to produce nanoparticle inks that make solar cells by printing. In this process, simulated sunlight is focused on the solar microreactor to rapidly heat it, while allowing precise control of temperature to aid the quality of the finished product. The light in these experiments was produced artificially, but the process could be done with direct sunlight, and at a fraction of the cost of current approaches.
  • LeopoldS on 09 Apr 14
     
    anybody interested in having a closer look at this?
Thijs Versloot

New Quantum Theory to explain flow of time - 2 views

www.wired.com/...quantum-theory-flow-time

energy quantum time

shared by Thijs Versloot on 26 Apr 14 - No Cached
  • Thijs Versloot on 26 Apr 14
     
    Basically quantum entanglement, or more accurately the dispersal and expansion of mixed quantum states, results in an apparent flow of time. Quantum information leaks out and the result is the move from a pure state (hot coffee) to a mixed state (cooled down) in which equilibrium is reached. Theoretically it is possible to get back to a pure state (coffee spontaneously heating up) but this statistical unlikelihood gives the appereance of irreversibility and hence a flow o time. I think an interesting question is then: how much useful work can you extract from this system? (http://arxiv.org/abs/1302.2811) It should for macroscopic thermodynamic systems lead to the Carnot cycle, but on smaller scales it might be possible to formulate a more general expression. Anybody interested to look into it? Anna, Jo? :)
  • johannessimon81 on 27 Apr 14
     
    What you propose is called Maxwell's demon: http://en.wikipedia.org/wiki/Maxwell%27s_demon Unfortunately (or maybe fortunately) thermodynamics is VERY robust. I guess if you really only want to harness AND USE the energy in a microscopic system you might have some chance of beating Carnot. But any way of transferring harvested energy to a macroscopic system seems to be limited by it (AFAIK).
Thijs Versloot

Vibrational free cooling systems for sensors - 1 views

www.utwente.nl/...dutch-space-slaan-handen-ineen

technology cooling sensor

shared by Thijs Versloot on 11 Jun 14 - No Cached
  • Thijs Versloot on 11 Jun 14
     
    The system is based on two liquids which are adsorbed. As the sensor generates heat, the liquids desorb and the pressure builds up, it can then move to an expansion vessel which is held at a cooler temperature and the liquid then adsorb together again. This technique requires no mechanical compression and there are less vibration, leading to less wear and tear of components. It is being developed in a joint collaboration between UTwente and Dutch Space.
Thijs Versloot

Magnetic bubble may give space probes a soft landing - 4 views

www.newscientist.com/article/mg22329763.100-magnetic-bubble-may-give-space-probes-a-soft-landing.html?cmpid=RSS|NSNS|2012-GLOBAL|physics-math#.U7aeTnWSzmE

magnetoshell aerocapture plasma entry

shared by Thijs Versloot on 04 Jul 14 - No Cached
  • Thijs Versloot on 04 Jul 14
     
    I am also looking into this idea since some time and it seems NASA is already ahead, awarding two contract to investigate magnetoshell aerocapture. This could be interesting for probes that want to enter eg Marsian atmospheres at relatively high velocity. Or for multiple re-entry s/c at Earth. The idea of the experiment, The satellite will carry a copper coil, powered by a lithium-ion battery, that generates a magnetic field around the probe. As it descends, the spacecraft will eject a small amount of plasma. This gets trapped in the magnetic field, creating a protective bubble that stops air molecules colliding with the craft and producing heat.
  • LeopoldS on 05 Jul 14
     
    A few years back Mimmo has worked on this, rather from the theory side if I remember well ...
  • Paul N on 11 Jul 14
     
    The power requirements for such a thing must be HUGE!
annaheffernan

New generator creates electricity directly from heat - 4 views

www.sciencedaily.com/...131203105935.htm

shared by annaheffernan on 09 Jan 14 - No Cached
  • Thijs Versloot on 09 Jan 14
     
    This would fit well with a study I saw on 'nanogrooved surfaces' with which you could make very good light absorbers. http://www.nature.com/ncomms/journal/v3/n7/full/ncomms1976.html?WT.ec_id=NCOMMS-20120724
Joris _

Spaceflight Now | Breaking News | Space agencies tackle waning plutonium stockpiles - 2 views

www.spaceflightnow.com/...09rtg

technology NRG

shared by Joris _ on 09 Jul 10 - Cached
  • For every 100 watts of heat that I've got, the best I can do is get 8 watts of electricity
  • NASA is developing an Advanced Stirling Radioisotope Generator to improve the efficiency by a factor of four
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