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Tom Gheysens

Discovery of a kernel for controlling biomolecular regulatory networks : Scientific Rep... - 1 views

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    What synthetic biology can offer to AI... 
Tom Gheysens

Controlling genes with light: New technique can rapidly turn genes on and off, helping ... - 1 views

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    New technique can rapidly turn genes on and off, helping scientists better understand their function.
Thijs Versloot

Quadcopter athetics - 2 views

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    Nice examples of multiple quadcopter control and feedback loops
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
Thijs Versloot

Does your iPhone have free will? #arXiv - 3 views

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    If you've ever found your iPhone taking control of your life, there may be a good reason. It may think it has free will. That may not be quite as far-fetched as it sounds. Today, one leading scientist outlines a 'Turing Test' for free will and says that while simple devices such as thermostats cannot pass, more complex ones like iPhones might.
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    An interesting paper about how you should *NOT* think about free will...
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    I must say that the fact that the outcome of a thought process is not evident to myself in advance sounds like a more plausible explanation than 'free will' being the product of quantum mechanics. The later would not only produce unpredictable decisions but probably also irrational ones...
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    Even if it were the product of quantum mechanics, it's still the result of external interference and not the result of 'free' will. It doesn't matter if the external input is deterministic or random, it's still external and it's not "YOU" that decided stuff.
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    I don't know the inventor of that nonsense that the free will should be the result of QM. It's about the only point I agree with the author of the paper: QM is not necessary and doesn't help. What I meant: all these thought experiments done by typical ultra-naive realists (or ultra-naive physicalists, if you prefer) that cultivate the university departments of physics, computer science etc. are put the cart before the horse. First one has to clarify the role of physical theories and its concepts (e.g. causality) and then one can start to ask how "free will" could perhaps be seen in these theories. More than 200 years ago there existed a famous philosopher named Kant who had some interesting thoughts about this. But authors like Lloyd behave as if he never existed, in fact is view of the world is even pre-Platonic!
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    Henry Kissinger How I'm missing yer And wishing you were here
Thijs Versloot

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

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    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.
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    anybody interested in having a closer look at this?
Tom Gheysens

The Moroccan flic-flac spider: A gymnast among the arachnids -- ScienceDaily - 5 views

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    New form of locomotion found in spiders. They say it could be used for a robot on Mars...don't immediately see how though. :)
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    Before it gets out of control... I hope you realise that quoting "Science Daily" in the context of science is pretty much like using Daily Mail as your reference news agency?
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    I was just going to post the same story. Here is BTW a video of the intended type of robot: https://www.youtube.com/watch?v=OHo32JrkDRk&feature=youtu.be
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    True Marek :) The article does quote a Journal Paper though ..... published in zootaxa: a staggering 0.9 impact factor journal!! And watching the video you immediately understand why :)
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    I of course watched the video and have trouble sleeping since.
jmlloren

Insect flight dynamics: Stability and control - 2 views

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    A recently published review on insect flight appeared in Review of Modern Physics. It might be of interest to the biomimetics unit.
Thijs Versloot

China team takes on tech challenge of supercavitation - 1 views

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    "A Soviet supercavitation torpedo called Shkval was able to reach a speed of 370km/h or more - much faster than any other conventional torpedoes," he said. However, The SCMP highlighted two problems in supercavitation technology. First, the submerged vessel needed to be launched at high speeds, approaching 100km/h, to generate and maintain the air bubble. Secondly, it is difficult if not impossible to steer the vessel using conventional mechanisms, which are inside the bubble, without direct contact with water. As a result, its application has been limited to unmanned vessels, fired in a straight line.
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    can't you just selectively inject the gas so that you control in which direction the bubble forms?
Marcus Maertens

Why Is This Giraffe Gnawing On An Impala Skull? - 3 views

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    Omg - they will not only murder you, but also suck on your bones.
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    Marcus, might be up your street? http://www.giraffobia.com/news.htm
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    Fantastic! Although my recent encounters with the species helped me control my giraffobia...
Thijs Versloot

Communicate through the plasma sheath during re-entry - 1 views

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    In order to overcome the communication blackout problem suffered by hypersonic vehicles, a matching approach has been proposed for the first time in this paper. It utilizes a double-positive (DPS) material layer surrounding a hypersonic vehicle antenna to match with the plasma sheath enclosing the vehicle. Or in more easy language, basically one provides an antenna as capacitor, in combination with the plasma sheath (an inductor), they form an electrical circuit which becomes transparent for long wavelength radiation (the communication signal). The reasons is that fluctuations are balanced by the twin system, preventing absorption/reflection of the incoming radiation. Elegant solution, but will only work on long wavelength communication, plus I am not sure whether the antenna needs active control (as the plasma sheath conditions change during the re-entry phase).
Thijs Versloot

Graphene coated silicon super-capacitors for energy storage - 1 views

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    Recharge in seconds and efficiently store power for weeks between charges. Added bonus is the cheap and abundant components needed. One of the applications they foresee is to attach such a super-capacitor to the back of solar panels to store the power and discharge this during the night
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    very nice indeed - is this already at a stage where we should have a closer look at it? what you think? With experience in growing carbon nanostructures, Pint's group decided to try to coat the porous silicon surface with carbon. "We had no idea what would happen," said Pint. "Typically, researchers grow graphene from silicon-carbide materials at temperatures in excess of 1400 degrees Celsius. But at lower temperatures - 600 to 700 degrees Celsius - we certainly didn't expect graphene-like material growth." When the researchers pulled the porous silicon out of the furnace, they found that it had turned from orange to purple or black. When they inspected it under a powerful scanning electron microscope they found that it looked nearly identical to the original material but it was coated by a layer of graphene a few nanometers thick. When the researchers tested the coated material they found that it had chemically stabilized the silicon surface. When they used it to make supercapacitors, they found that the graphene coating improved energy densities by over two orders of magnitude compared to those made from uncoated porous silicon and significantly better than commercial supercapacitors. Transmission electron microscope image of the surface of porous silicon coated with graphene. The coating consists of a thin layer of 5-10 layers of graphene which filled pores with diameters less than 2-3 nanometers and so did not alter the nanoscale architecture of the underlying silicon. (Cary Pint / Vanderbilt) The graphene layer acts as an atomically thin protective coating. Pint and his group argue that this approach isn't limited to graphene. "The ability to engineer surfaces with atomically thin layers of materials combined with the control achieved in designing porous materials opens opportunities for a number of different applications beyond energy storage," he said.
Athanasia Nikolaou

Study finds link between the atmospheric rivers and climate - 1 views

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    Atmospheric rivers, short-lived wind tunnels are created in the upper troposphere and carry vast amounts of water. They 'fuel' from the tropical Pacific reservoir and cause heavy precipitation events and even floods to mid-latitude land, as soon as they encounter the Sierra mountains. The new finding is that two inter-hemispheric climatic oscillation modes allow for their creation, as soon as they are found in a certain phase combination.
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    Could we conceivably control these like we're thinking to do with taifuns? :)) Would be geoengineering at its finest
Nina Nadine Ridder

Microscopic fish are 3-D-printed to do more than swim: Researchers demonstrate a novel ... - 1 views

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    Useful for space exploration, e.g. subsurface water reservoirs such as Europa or Enceladus? Nanoengineers at the University of California, San Diego used an innovative 3-D printing technology they developed to manufacture multipurpose fish-shaped microrobots -- called microfish -- that swim around efficiently in liquids, are chemically powered by hydrogen peroxide and magnetically controlled.
Juxi Leitner

YouTube - The latest version of the LittleDog Robot - 3 views

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    whoa!!!
pacome delva

Physics - Electronics without solids - 0 views

  • The idea is to someday use such a circuit to study basic many-body physics in a completely controlled and adjustable system, without the messiness of crystal defects or impurities found in real semiconductors.
pacome delva

Physics - Small-scale hydraulics - 1 views

  • Taking a cue from biology, scientists are now designing nanofluidic devices in which molecular interactions at the walls of a narrow channel are engineered to control fluid flow.
pacome delva

Metamaterials Probe Changes in Spacetime Structure | Physical Review Focus - 0 views

  • At the time of the big bang, our universe may not have had exactly three dimensions of space and one of time, according to some theorists. In the 6 August Physical Review Letters, a team proposes a way to observe the postulated transition to our current universe using so-called metamaterials, structures in which the propagation of light can be precisely controlled. Experiments on such structures, they say, could test predictions that a "big flash" of radiation would accompany changes in the structure of spacetime that may have occurred in the early universe.
pacome delva

An evil atmosphere is forming around geoengineering - 0 views

  • A number of right-wing think tanks actively denying climate change are also promoting geoengineering, an irony that seems to escape them.
  • Wood believes that climate engineering is inevitable. In a statement that could serve as Earth's epitaph, he declared: "We've engineered every other environment we live in, why not the planet?"
  • It's estimated that if whoever controls the scheme decided to stop, the greenhouse gases that would have built up could cause warming to rebound at a rate 10 to 20 times that of the recent past - a phenomenon referred to, apparently without irony, as the "termination problem".
Joris _

Spaceflight Now | Breaking News | Sweden's Prisma satellites go their separate ways - 1 views

  • exotic green propellant maneuvering systems
  • In the two months since launch, controllers have powered up the satellites' navigation and formation flying equipment, tested its green propellant thruster, and successfully navigated around orbital debris threats.
  • a smorgasbord of payloads
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