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Thijs Versloot

Bicycle airbag #howitworks - 2 views

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    Thousands of cycling accidents were re-enacted using stunt riders and crash-test dummies to collect the specific movement patterns of cyclists in accidents. In parallel, normal cycling data has been collected using test cyclists wearing Hövding in everyday cycling. Based on this collected data, they have developed an algorithm that can distinguish normal cycling from accidents. As you don't want the 399GBP device to inflate when taking a sharp corner...
johannessimon81

18-year-old massively improves supercapacitors during Intel International Science and E... - 1 views

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    "Her goal was to design and synthesise a super capacitor with increased energy density while maintaining power density and long cycle life. She designed, synthesised and characterised a novel core-shell nanorod electrode with hydrogemated TiO2(H-TiO2) core and polyaniline shell. H-TiO2 acts as the double layer electrostatic core. Good conductivity of H-TiO2 combined with the high pseudo capacitance of polyaniline results in significantly higher overall capacitance and energy density while retaining good power density and cycle life. This new electrode was fabricated into a flexible solid-state device to light an LED to test it in a practical application. Khare then evaluated the structural and electrochemical properties of the new electrode. It demonstrated high capacitance of 203.3 mF/cm2 (238.5 F/g) compared to the next best alternative super capacitor in previous research of 80 F/g, due to the design of the core-shell structure. This resulted in excellent energy density of 20.1 Wh/kg, comparable to batteries, while maintaining a high power density of 20540 W/kg. It also demonstrated a much higher cycle life compared to batteries, with a low 32.5% capacitance loss over 10,000 cycles at a high scan rate of 200 mV/s."
johannessimon81

Mathematicians Predict the Future With Data From the Past - 6 views

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    Asimov's Foundation meets ACT's Tipping Point Prediction?
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    Good luck to them!!
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    "Mathematicians Predict the Future With Data From the Past". GREAT! And physicists probably predict the past with data from the future?!? "scientists and mathematicians analyze history in the hopes of finding patterns they can then use to predict the future". Big deal! That's what any scientist does anyway... "cliodynamics"!? Give me a break!
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    still, some interesting thoughts in there ... "Then you have the 50-year cycles of violence. Turchin describes these as the building up and then the release of pressure. Each time, social inequality creeps up over the decades, then reaches a breaking point. Reforms are made, but over time, those reforms are reversed, leading back to a state of increasing social inequality. The graph above shows how regular these spikes are - though there's one missing in the early 19th century, which Turchin attributes to the relative prosperity that characterized the time. He also notes that the severity of the spikes can vary depending on how governments respond to the problem. Turchin says that the United States was in a pre-revolutionary state in the 1910s, but there was a steep drop-off in violence after the 1920s because of the progressive era. The governing class made decisions to reign in corporations and allowed workers to air grievances. These policies reduced the pressure, he says, and prevented revolution. The United Kingdom was also able to avoid revolution through reforms in the 19th century, according to Turchin. But the most common way for these things to resolve themselves is through violence. Turchin takes pains to emphasize that the cycles are not the result of iron-clad rules of history, but of feedback loops - just like in ecology. "In a predator-prey cycle, such as mice and weasels or hares and lynx, the reason why populations go through periodic booms and busts has nothing to do with any external clocks," he writes. "As mice become abundant, weasels breed like crazy and multiply. Then they eat down most of the mice and starve to death themselves, at which point the few surviving mice begin breeding like crazy and the cycle repeats." There are competing theories as well. A group of researchers at the New England Complex Systems Institute - who practice a discipline called econophysics - have built their own model of political violence and
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    It's not the scientific activity described in the article that is uninteresting, on the contrary! But the way it is described is just a bad joke. Once again the results itself are seemingly not sexy enough and thus something is sold as the big revolution, though it's just the application of the oldest scientific principles in a slightly different way than used before.
Joris _

Sound Waves on Distant Star Reveal Sun-Like Cycle - 1 views

  • Astronomers studying sound waves on a distant star have discovered that it has a magnetic cycle similar to our sun's solar cycle.
ESA ACT

Johnson Electro Mechanical Systems - 0 views

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    he JTEC is an all solid-state engine that operates on the Ericsson cycle. Equivalent to Carnot, the Ericsson cycle offers the maximum theoretical efficiency available from an engine operating between two temperatures.
Joris _

Obama's dream of Mars at risk from radiation - physicsworld.com - 0 views

  • Schwabe cycle
  • Schwabe cycle, where sunspot numbers reach a peak roughly once every 11 years
  • the intensity of each solar maximum is also thought to oscillate over a period, called the Gleissberg cycle
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  • The worse-case scenario is that if you radiate a crew sufficiently, they'd all succumb to radiation sickness within a few days and essentially vomit and diarrhoea themselves to death within an enclosed capsule
  • The Moon missions were just blind lucky,” explains Lewis Dartnell, an astrobiologist at University College, London. “The astronauts would have experienced radiation sickness and a higher risk of future cancer if they'd been hit,” he adds.
  • Hapgood and colleagues are currently working on an alternative technique that involves surrounding the spacecraft with a plasma shield to deflect incoming protons without creating secondary radiation
santecarloni

Optical measurement of cycle-dependent cell growth - 0 views

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    Researchers developed a new imaging method that can measure cell mass using two beams of light, offering new insight into the much-debated problem of whether cells grow at a constant rate or exponentially. They found that mammalian cells show clear exponential growth only during the G2 phase of the cell cycle. This information has great implications not only for basic biology, but also for diagnostics, drug development and tissue engineering.
Thijs Versloot

Sulfur Graphene Oxides for high performance #EV batteries #Berkeley - 0 views

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    Test cell reaches 500Wh/kg and about a 1000 cycles. Graphene is excellent to use as it can handle the thermal expansion during charge cycles which normally destroy the cathodes and thereby degrade performance over time.
Nina Nadine Ridder

Stratospheric Water Vapor is a Global Warming Wild Card - 1 views

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    Climate models are not able to reproduce the observed decrease in stratospheric water vapor which shows that the global water cycle is still not known well enough and further research is desperately needed. 
Francesco Biscani

Freeze-thaw cycle may explain Saturn moon's odd activity - space - 29 May 2009 - New Sc... - 0 views

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    Pretty amazing Celestial Mechanics effects that could potentially help creation of life...
ESA ACT

ZetaGrid - 0 views

shared by ESA ACT on 24 Apr 09 - Cached
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    ZetaGrid is a platform independent grid system that uses idle CPU cycles from participating computers. Problem: The ZetaGrid activities must come to a final end! Now all services are down and this domain will be closed soon. The official last update note
ESA ACT

MRS Issue on Molecular biomimetics - 0 views

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    In nature, the molecular-recognition ability of peptides and, consequently, their functions are evolved through successive cycles of mutation and selection. Using biology as a guide, we can now select, tailor, and control peptide-solid interactions and ex
ESA ACT

Why Sleep? | Physical Review Focus - 0 views

shared by ESA ACT on 24 Apr 09 - Cached
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    A study in the January Physical Review E suggests that a sleep-wake cycle, allowing the brain to focus on one task at a time, may be the most efficient way to operate. The researcher shows mathematically that processing a continuously changing resource--s
ESA ACT

Buienradar.nl - Weer - Actuele neerslag en weerbericht - 0 views

shared by ESA ACT on 24 Apr 09 - Cached
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    For all those of ACT who want to cycle to work: the RAINradar.
Thijs Versloot

Alternative sleep cycles - 1 views

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    Give the Ubermancycle a try?
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    I was into this some time ago and found a documentary in which they performed an experiment on a guy. Long story short, it didn't work that good. He was semi-lucid all the time and his mental performance dropped. Perhaps it is possible to survive like this for months, but if your goal is to maximize your daily output, you will not gain extra work hours due to being 3/4 conscious most of the time. EDIT: Not related to the documentary I mentioned but some first hand stories: http://www.reddit.com/r/IAmA/comments/co5t9/i_attempted_polyphasic_sleep_for_a_documentary_ama/c0tza1e
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    I also heard about it. At the moment, I am on some sort of bi-phasic sleep and I am not feeling more tired than with the monophasic one (while sleeping effectively less right now).
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    If it exists, there's an xkcd about it: http://xkcd.com/320/ Actually the schedule proposed there is quite useful if you're into this whole Friday / Saturday night thing..
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    I don't see why it wouldn't work if you manage to detach yourself from the cycardian input. As in never ever see sun and daylight :))
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    > As in never ever see sun and daylight :)) Like in the Netherlands you mean?
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    Tri-phasic sleep rhythm works fine.
fichbio

Long-Term Space Flight Simulation Reveals Infradian Rhythmicity in Human Na + Balance - 3 views

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    For the first time scientists have identified monthly hormonal cycles in human males
LeopoldS

Nuclear powered drones? - 2 views

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    Not explicit but smells like RTGs
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    "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.
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    The quote "it was disappointing to all that the political realities would not allow use of the results" may refer to RTGs too :-)
LeopoldS

Current Biology - Evidence that the Lunar Cycle Influences Human Sleep - 1 views

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    looks like a mythbuster paper!
Athanasia Nikolaou

Nature Paper: Rivers and streams release more CO2 than previously believed - 6 views

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    Another underestimated source of CO2, are turbulent waters. "The stronger the turbulences at the water's surface, the more CO2 is released into the atmosphere. The combination of maps and data revealed that, while the CO2 emissions from lakes and reservoirs are lower than assumed, those from rivers and streams are three times as high as previously believed." Alltogether the emitted CO2 equates to roughly one-fifth of the emissions caused by humans. Yet more stuff to model...
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    This could also be a mechanism to counter human CO2 emission ... the more we emit, the less turbulent rivers and stream, the less CO2 is emitted there ... makes sense?
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    I guess there is a natural equilibrium there. Once the climate warms up enough for all rivers and streams to evaporate they will not contribute CO2 anymore - which stops their contribution to global warming. So the problem is also the solution (as always).
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    "The source of inland water CO2 is still not known with certainty and new studies are needed to research the mechanisms controlling CO2 evasion globally." It is another source of CO2 this one, and the turbulence in the rivers is independent of our emissions in CO2 and just facilitates the process of releasing CO2 waters. Dario, if I understood correct you have in mind a finite quantity of CO2 that the atmosphere can accomodate, and to my knowledge this does not happen, so I cannot find a relevant feedback there. Johannes, H2O is a powerful greenhouse gas :-)
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    Nasia I think you did not get my point (a joke, really, that Johannes continued) .... by emitting more CO2 we warm up the planet thus drying up rivers and lakes which will, in turn emit less CO2 :) No finite quantity of CO2 in the atmosphere is needed to close this loop ... ... as for the H2O it could just go into non turbulent waters rather than staying into the atmosphere ...
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    Really awkward joke explanation: I got the joke of Johannes, but maybe you did not get mine: by warming up the planet to get rid of the rivers and their problems, the water of the rivers will be accomodated in the atmosphere, therefore, the greenhouse gas of water.
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    from my previous post: "... as for the H2O it could just go into non turbulent waters rather than staying into the atmosphere ..."
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    I guess the emphasis is on "could"... ;-) Also, everybody knows that rain is cold - so more water in the atmosphere makes the climate colder.
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    do you have the nature paper also? looks like very nice, meticulous typically german research lasting over 10 years with painstakingly many researchers from all over the world involved .... and while important the total is still only 20% of human emissions ... so a variation in it does not seem to change the overall picture
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    here is the nature paper : http://www.nature.com/nature/journal/v503/n7476/full/nature12760.html I appreciate Johannes' and Dario's jokes, since climate is the common ground that all of us can have an opinion, taking honours from experiencing weather. But, the same as if I am trying to make jokes for material science, or A.I. I take a high risk of failing(!) :-S Water is a greenhouse gas, rain rather releases latent heat to the environment in order to be formed, Johannes, nice trolling effort ;-) Between this and the next jokes to come, I would stop to take a look here, provided you have 10 minutes: how/where rain forms http://www.scribd.com/doc/58033704/Tephigrams-for-Dummies
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    omg
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    Nasia, I thought about your statement carefully - and I cannot agree with you. Water is not a greenhouse gas. It is instead a liquid. Also, I can't believe you keep feeding the troll! :-P But on a more topical note: I think it is an over-simplification to call water a greenhouse gas - water is one of the most important mechanisms in the way Earth handles heat input from the sun. The latent heat that you mention actually cools Earth: solar energy that would otherwise heat Earth's surface is ABSORBED as latent heat by water which consequently evaporates - the same water condenses into rain drops at high altitudes and releases this stored heat. In effect the water cycle is a mechanism of heat transport from low altitude to high altitude where the chance of infrared radiation escaping into space is much higher due to the much thinner layer of atmosphere above (including the smaller abundance of greenhouse gasses). Also, as I know you are well aware, the cloud cover that results from water condensation in the troposphere dramatically increases albedo which has a cooling effect on climate. Furthermore the heat capacity of wet air ("humid heat") is much larger than that of dry air - so any advective heat transfer due to air currents is more efficient in wet air - transporting heat from warm areas to a natural heat sink e.g. polar regions. Of course there are also climate heating effects of water like the absorption of IR radiation. But I stand by my statement (as defended in the above) that rain cools the atmosphere. Oh and also some nice reading material on the complexities related to climate feedback due to sea surface temperature: http://journals.ametsoc.org/doi/abs/10.1175/1520-0442(1993)006%3C2049%3ALSEOTR%3E2.0.CO%3B2
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    I enjoy trolling conversations when there is a gain for both sides at the end :-) . I had to check upon some of the facts in order to explain my self properly. The IPCC report states the greenhouse gases here, and water vapour is included: http://www.ipcc.ch/publications_and_data/ar4/wg1/en/faq-2-1.html Honestly, I read only the abstract of the article you posted, which is a very interesting hypothesis on the mechanism of regulating sea surface temperature, but it is very localized to the tropics (vivid convection, storms) a region of which I have very little expertise, and is difficult to study because it has non-hydrostatic dynamics. The only thing I can comment there is that the authors define constant relative humidity for the bottom layer, supplied by the oceanic surface, which limits the implementation of the concept on other earth regions. Also, we may confuse during the conversation the greenhouse gas with the Radiative Forcing of each greenhouse gas: I see your point of the latent heat trapped in the water vapour, and I agree, but the effect of the water is that it traps even as latent heat an amount of LR that would otherwise escape back to space. That is the greenhouse gas identity and an image to see the absorption bands in the atmosphere and how important the water is, without vain authority-based arguments that miss the explanation in the end: http://www.google.nl/imgres?imgurl=http://www.solarchords.com/uploaded/82/87-33833-450015_44absorbspec.gif&imgrefurl=http://www.solarchords.com/agw-science/4/greenhouse--1-radiation/33784/&h=468&w=458&sz=28&tbnid=x2NtfKh5OPM7lM:&tbnh=98&tbnw=96&zoom=1&usg=__KldteWbV19nVPbbsC4jsOgzCK6E=&docid=cMRZ9f22jbtYPM&sa=X&ei=SwynUq2TMqiS0QXVq4C4Aw&ved=0CDkQ9QEwAw
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