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ESA ACT

NASA - A Telescope Made of Moondust - 0 views

science.nasa.gov/...09jul_moonscope.htm

NAN astronomy technology

shared by ESA ACT on 24 Apr 09 - Cached
  • ESA ACT on 24 Apr 09
     
    Composite materials are synthetic materials made by mixing fibers or granules of various materials into epoxy and letting the mixture harden. Composites combine two valuable properties: ultralight weight and extraordinary strength.
Thijs Versloot

Repeated self-healing in composite materials - 1 views

phys.org/...aling-composite-materials.html

materials healing

shared by Thijs Versloot on 16 Apr 14 - No Cached
  • Thijs Versloot on 16 Apr 14
     
    Sottos, White, Moore, and their team created 3D vascular networks-patterns of microchannels filled with healing chemistries-that thread through a fiber-reinforced composite. When damage occurs, the networks within the material break apart and allow the healing chemistries to mix and polymerize, autonomously healing the material, over multiple cycles.
Ma Ru

An optimization algorithm inspired by musical composition - 3 views

www.springerlink.com/...n6hwlvp607587787

INF optimisation PyGMO music composition article science

shared by Ma Ru on 04 Jan 12 - No Cached
  • Ma Ru on 04 Jan 12
     
    For PyGMO 2.0 ...
LeopoldS

Plant sciences: Plants drink mineral water : Nature : Nature Publishing Group - 1 views

www.nature.com/...512351e.html

plant water Mars exploration terraforming

shared by LeopoldS on 02 Sep 14 - No Cached
  • LeopoldS on 02 Sep 14
     
    Here we go: we might not need liquid water after all on mars to get some nice flowering plants there! ... and terraform ? :-) Thirsty plants can extract water from the crystalline structure of gypsum, a rock-forming mineral found in soil on Earth and Mars.

    Some plants grow on gypsum outcrops and remain active even during dry summer months, despite having shallow roots that cannot reach the water table. Sara Palacio of the Pyrenean Institute of Ecology in Jaca, Spain, and her colleagues compared the isotopic composition of sap from one such plant, called Helianthemum squamatum (pictured), with gypsum crystallization water and water found free in the soil. The team found that up to 90% of the plant's summer water supply came from gypsum.

    The study has implications for the search for life in extreme environments on this planet and others.

    Nature Commun 5, 4660 (2014)
  • Athanasia Nikolaou on 02 Sep 14
     
    Very interesting indeed. Attention is to be put on the form of calcium sulfate that is found on Mars. If it is hydrated (gypsum Ca(SO4)*2(H2O)) it works, but if it is dehydrated there is no water for the roots to take in. The Curiosity Rover tries to find out, but has uncertainty in recognising the hydrogen presence in the mineral: Copying : "(...) 3.2 Hydration state of calcium sulfates Calcium sulfates occur as a non-hydrated phase (anhydrite, CaSO4) or as one of two hydrated phases (bassanite, CaSO4.1/2H2O, which can contain a somewhat variable water content, and gypsum, CaSO4.2H2O). ChemCam identifies the presence of hydrogen at 656 nm, as already found in soils and dust [Meslin et al., 2013] and within fluvial conglomerates [Williams et al., 2013]. However, the quantification of H is strongly affected by matrix effects [Schröder et al., 2013], i.e. effects including major or even minor element chemistry, optical and mechanical properties, that can result in variations of emission lines unrelated to actual quantitative variations of the element in question in the sample. Due to these effects, discriminating between bassanite and gypsum is difficult. (...)"
  • Athanasia Nikolaou on 02 Sep 14
jmlloren

Exotic matter : Insight : Nature - 5 views

www.nature.com/...index.html

nan phy

shared by jmlloren on 03 Aug 10 - Cached
LeopoldS liked it
  • jmlloren on 03 Aug 10
     
    Trends in materials and condensed matter. Check out the topological insulators. amazing field.
  • ...12 more comments...
  • Luzi Bergamin on 03 Aug 10
     
    Aparently very interesting, will it survive the short hype? Relevant work describing mirror charges of topological insulators and the classical boundary conditions were done by Ismo and Ari. But the two communities don't know each other and so they are never cited. Also a way to produce new things...
  • jmlloren on 04 Aug 10
     
    Thanks for noticing! Indeed, I had no idea that Ari (don't know Ismo) was involved in the field. Was it before Kane's proposal or more recently? What I mostly like is that semiconductors are good candidates for 3D TI, however I got lost in the quantum field jargon. Yesterday, I got a headache trying to follow the Majorana fermions, the merons, skyrnions, axions, and so on. Luzi, are all these things familiar to you?
  • Luzi Bergamin on 04 Aug 10
     
    Ismo Lindell described in the early 90's the mirror charge of what is now called topological insulator. He says that similar results were obtained already at the beginning of the 20th century... Ismo Lindell and Ari Sihvola in the recent years discussed engineering aspects of PEMCs (perfect electro-megnetic conductors,) which are more or less classical analogues of topological insulators. Fundamental aspects of PEMCs are well knwon in high-energy physics for a long time, recent works are mainly due to Friedrich Hehl and Yuri Obukhov. All these works are purely classical, so there is no charge quantisation, no considerations of electron spin etc. About Majorana fermions: yes, I spent several years of research on that topic. Axions: a topological state, of course, trivial :-) Also merons and skyrnions are topological states, but I'm less familiar with them.
  • LeopoldS on 04 Aug 10
     
    "Non-Abelian systems1, 2 contain composite particles that are neither fermions nor bosons and have a quantum statistics that is far richer than that offered by the fermion-boson dichotomy. The presence of such quasiparticles manifests itself in two remarkable ways. First, it leads to a degeneracy of the ground state that is not based on simple symmetry considerations and is robust against perturbations and interactions with the environment. Second, an interchange of two quasiparticles does not merely multiply the wavefunction by a sign, as is the case for fermions and bosons. Rather, it takes the system from one ground state to another. If a series of interchanges is made, the final state of the system will depend on the order in which these interchanges are being carried out, in sharp contrast to what happens when similar operations are performed on identical fermions or bosons." wow, this paper by Stern reads really weired ... any of you ever looked into this?
  • jmlloren on 04 Aug 10
     
    C'mon Leopold, it's as trivial as the topological states, AKA axions! Regarding the question, not me!
  • LeopoldS on 04 Aug 10
     
    just looked up the wikipedia entry on axions .... at least they have some creativity in names giving: "In supersymmetric theories the axion has both a scalar and a fermionic superpartner. The fermionic superpartner of the axion is called the axino, the scalar superpartner is called the saxion. In some models, the saxion is the dilaton. They are all bundled up in a chiral superfield. The axino has been predicted to be the lightest supersymmetric particle in such a model.[24] In part due to this property, it is considered a candidate for the composition of dark matter.[25]"
  • jmlloren on 04 Aug 10
     
    Thank's Leopold. Sorry Luzi for being ironic concerning the triviality of the axions. Now, Leo confirmed me that indeed is a trivial matter. I have problems with models where EVERYTHING is involved.
  • Luzi Bergamin on 04 Aug 10
     
    Well, that's the theory of everything, isn't it?? Seriously: I don't think that theoretically there is a lot of new stuff here. Topological aspects of (non-Abelian) theories became extremely popular in the context of string theory. The reason is very simple: topological theories are much simpler than "normal" and since string theory anyway is far too complicated to be solved, people just consider purely topological theories, then claiming that this has something to do with the real world, which of course is plainly wrong. So what I think is new about these topological insulators are the claims that one can actually fabricate a material which more or less accurately mimics a topological theory and that these materials are of practical use. Still, they are a little bit the poor man's version of the topological theories fundamental physicists like to look at since electrdynamics is an Abelian theory.
  • jmlloren on 04 Aug 10
     
    I have the feeling, not the knowledge, that you are right. However, I think that the implications of this light quantum field effects are great. The fact of being able to sustain two currents polarized in spin is a technological breakthrough.
  • LeopoldS on 04 Aug 10
     
    not sure how much I can contribute to your apparently educated debate here but if I remember well from my work for the master, these non-Abelian theories were all but "simple" as Luzi puts it ... and from a different perspective: to me the whole thing of being able to describe such non-Abelian systems nicely indicates that they should in one way or another also have some appearance in Nature (would be very surprised if not) - though this is of course no argument that makes string theory any better or closer to what Luzi called reality ....
  • Luzi Bergamin on 04 Aug 10
     
    Well, electrodynamics remains an Abelian theory. From the theoretical point of view this is less interesting than non-Abelian ones, since in 4D the fibre bundle of a U(1) theory is trivial (great buzz words, eh!) But in topological insulators the point of view is slightly different since one always has the insulator (topological theory), its surrounding (propagating theory) and most importantly the interface between the two. This is a new situation that people from field and string theory were not really interested in.
  • Dario Izzo on 04 Aug 10
     
    guys... how would you explain this to your gran mothers?
  • jmlloren on 05 Aug 10
  • LeopoldS on 07 Aug 10
     
    *you* tried *your* best .... ??
ESA ACT

Microscale Environments Could Be Probed By Super Small Nanoelectrodes - 0 views

www.medicalnewstoday.com/medicalnews.php

NAN BIO technology analysis cell

shared by ESA ACT on 24 Apr 09 - Cached
  • ESA ACT on 24 Apr 09
     
    Investigating the composition and behavior of microscale environments, including those within living cells, could become easier and more precise with nanoelectrodes being developed at the University of Illinois.
ESA ACT

Flexible screen based on thermochromic effect: Paperlike thermochromic display - 0 views

scitation.aip.org/...GetabsServlet

NAN technology optoelectronic

shared by ESA ACT on 24 Apr 09 - No Cached
  • ESA ACT on 24 Apr 09
     
    The authors report the design and implementation of a paperlike, thermally activated display fabricated from thermochromic composite and embedded conductive wiring patterns, shaped from mixture of metallic nanoparticles in polydimethylsioxane using soft l
ESA ACT

Ultrastrong and Stiff Layered Polymer Nanocomposites -- Podsiadlo et al. 318 (5847): 80... - 0 views

www.sciencemag.org/...80

NAN BIO

shared by ESA ACT on 24 Apr 09 - Cached
  • ESA ACT on 24 Apr 09
     
    Imitating bio-composites (enamel, cuticula,...) could become feasible with nanotechnology.
ESA ACT

Mystery mechanism heals high-tech composite - tech - 05 December 2007 - New Scientist Tech - 0 views

technology.newscientist.com/...heals-hightech-composite-.html

science NAN materials

shared by ESA ACT on 24 Apr 09 - Cached
  • ESA ACT on 24 Apr 09
     
    interesting .... have they so far been involved?
LeopoldS

Prepare and transmit electronic text - American Institute of Physics - 2 views

www.aip.org/...compuscript.html

acta futura publications latex xml INF

shared by LeopoldS on 07 Nov 09 - Cached
  • LeopoldS on 07 Nov 09
     
    new revTex version available ... what do they mean by this? how do they use XML and latex to XML? would this also be an option for acta futura? "While we appreciate the benefits to authors of preparing manuscripts in TeX, especially for math-intensive manuscripts, it is neither a cost-effective composition tool (for the volume of pages AIP currently produces) nor is it a format that can be used effectively for online publishing."
  • Francesco Biscani on 11 Nov 09
     
    Dunno really, they may have some in-house process that converts LaTeX to XML for some reason. Probably they are using some subset of SGML, the standard generalized markup language from which both HTML and XML derive. Don't think is really relevant for Acta Futura, and the rest of the world seems to get along with TeX just fine...
hannalakk

Design of a multi-agent, fiber composite digital fabrication system | Science Robotics - 3 views

robotics.sciencemag.org/...eaau5630.full

space architecture robotics fiberglass

shared by hannalakk on 27 Sep 18 - No Cached
icheibas liked it
  • hannalakk on 27 Sep 18
     
    Swarm-based fabrication of interwoven composite tubes via a fully autonomous, cooperative system can help create architectural-scale structures in effective and efficient ways, including in remote environments.
johannessimon81

Wood pulp extract stronger than carbon fiber or Kevlar - 0 views

www.gizmag.com/...23959

bio technology phy science

shared by johannessimon81 on 23 Oct 12 - No Cached
  • johannessimon81 on 23 Oct 12
     
    The Forest Products Laboratory of the US Forest Service has opened a US$1.7 million pilot plant for the production of cellulose nanocrystals (CNC) from wood by-products materials such as wood chips and sawdust. Prepared properly, CNCs are stronger and stiffer than Kevlar or carbon fibers, so that putting CNC into composite materials results in high strength, low weight products.
santecarloni

Pristine relics of the Big Bang spotted - physicsworld.com - 1 views

physicsworld.com/...47769

Universe Phy space

shared by santecarloni on 11 Nov 11 - No Cached
LeopoldS liked it
  • santecarloni on 11 Nov 11
     
    For the first time, astronomers have discovered two distant clouds of gas that seem to be pure relics from the Big Bang.
  • LeopoldS on 12 Nov 11
     
    and one of them is in "leo" .... "This gas is of primordial composition, as it was produced during the first few minutes after the Big Bang." One gas cloud resides in the constellation Leo"
Thijs Versloot

3D Printable Graphene Composite - 1 views

www.nature.com/srep11181

technology energy storage graphene 3d

shared by Thijs Versloot on 21 Jul 15 - No Cached
LeopoldS liked it
  • Thijs Versloot on 21 Jul 15
     
    Both graphene and 3d printing has been around for quite a while, but combined they could provide unique properties of materials, eg in the use of high performance 3d batteries. This paper gives a nice overview of what has been done in the field up to now.
jcunha

AGM2015: Antineutrino Global Map 2015 : Scientific Reports - 1 views

www.nature.com/srep13945

PHY fun

shared by jcunha on 08 Sep 15 - No Cached
  • jcunha on 08 Sep 15
     
    Cool study about measuring antineutrino emissions in order to prospect composition of Earth's crust and mantle.
Marcus Maertens

[1806.03856] Computing the minimal crew for a multi-generational space travel towards P... - 5 views

arxiv.org/1806.03856

BIO science space

shared by Marcus Maertens on 16 Jul 18 - No Cached
  • Marcus Maertens on 16 Jul 18
     
    How many people to we actually need put on that ship?
  • Dario Izzo on 16 Jul 18
     
    We should invite these people to the AF special issue
  • marliesarnhof on 17 Jul 18
     
    sounds really interesting. their simulations don't account for biological issues (mutation, migration, selection, drift, founder effect) though, so the numbers are very low. this paper (https://ac.els-cdn.com/S0094576513004669/1-s2.0-S0094576513004669-main.pdf?_tid=6bec2a5c-f05f-4024-b4de-af78ab06fd42&acdnat=1531827379_d4f0be1b193873890d6e5b4574e82f2e) takes those effects and their implications on genetic composition of populations into account, but the numbers are enormous. do you have an idea why they (marin and beluffi) wouldn't put those effects into the simulations?
derekaranguren

Scientists release first analysis of rocks plucked from speeding asteroid - 0 views

phys.org/...hance-chemically-pristine.html

shared by derekaranguren on 10 Jun 22 - No Cached
  • derekaranguren on 10 Jun 22
     
    On the topic of asteroid composition :)
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