Fossil fuels? No thanks, I use water!
It is possible to generate electric power simply by using water.
This astonishing result can be reached exploiting the salinity difference
between water from the sea and water from a river, giving brackish water
as the only waste product. Some solutions of this kind have been already
proposed, but none of them is actually viable, due to high costs or
technical difficulties.
Here I describe a radically new technique, derived from supercapacitor
technology. Two porous electrodes, immersed in sea water, constitute a
capacitor, that is a device storing electric energy, somehow similar to
a battery. When the capacitor is charged, positive and negative salt ions
(red and green in the picture) migrate towards the oppositely charged
electrode, thus neutralizing them, and are kept in the electrode pores
like water in a sponge. After charging, the salt solution is brought
into contact with fresh water: the ions are washed away from the electrodes.
Since the electric charge of each electrode is no more counterbalanced
by salt ions, the electric potential of the capacitor becomes increased.
It is possible to extract the energy in excess in the form of
electric current, thus turning salinity difference into a
completely renewable energy source.
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LC12635
PARTICLES AS TRACERS FOR THE MOST MASSIVE EXPLOSIONS IN THE MILKY WAY
At their deaths, the most massive stars in the Milky Way seem to leave
behind unambiguous signatures of particles. Recently, a mysterious
population of electrons and positrons was observed by several
experiments. Attempts were made to attribute such a signal to the decay of
dark matter, an unknown kind of matter in our universe. But nature may
provide an even simpler solution to the problem, as reported in an article
in Physical Review Letters, finds a natural
explanation in the explosions of giant stars that are more than 15 times
heavier than our sun. A dying star of very high mass ejects most of its
matter in a final explosion, which then ploughs its way through a massive
stellar wind. During this process, electrons and positrons escape from two
different regions: the lower energy signal comes from the entire surface
of the exploding star, while at higher energies, the regions around the
poles of the rotating star start to dominate. This naturally explains the
observed energy behavior of electrons and positrons.
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LD12352E
Geometry of genetic logic gates
Genes integrate signals by transcription factors, often in a manner of combinatorial control in analogy with Boolean logic operations that basic electronic devices perform. Knowing which mode of combinatorial regulation (typically, AND or OR operation) that a gene employs is important for determining its function in regulatory networks. We propose an efficient approach to infer regulatory synergies, based on geometric characteristic of a physical quantity (i.e., so-called dynamic triple cross correlation) that can be computed directly from available experimental data, e.g., the cross correlation function with AND operation is convex and the one with OR operation is concave. Such an approach uses only the nature of noise inherent in gene regulation processes but does not need any external intervention, thus having potential application perspectives.
***
LZ11379
Casimir force confronts a new challenge from good, old electrostatic
effects
When two conducting plates are facing each other in vacuum, a mutual
attraction takes action simply due to a presence of the so-called virtual
photons of zero point energy. This charming force, also known as the
Casimir effect, is a force of pure quantum fluctuation and has attracted
immense interest among physicists in the last decade, with the latest
experiments showing a satisfactory agreement with its theoretical
prediction. Now, we closely inspect the surfaces used in our measurements
and ask ourselves, "How clean, how perfect are these? Is there enough
experimental control to nullify the familiar force of residual electric
fields that are rampant in any real surface?" Our paper concerns the first
measurement of the Casimir force between a pair of Germanium plates in
which a force due to surface potential patches appears to coexist with the
Casimir force, posing a great, new challenge on this modern, precision
measurement- deja vu of those ongoing gravitational wave projects like
LIGO and LISA. Whether the experimental data are to be attributed to the
Casimir force of quantum vacuum fluctuation or electrostatic force due to
spatial fluctuation of surface patches will require a detailed knowledge
of surface profile of a given sample under study. Our results underscore
the inherent difficulty associated with distinction of forces of different
physical origins. Dr. Casimir is perhaps right, but that does not mean
that we can completely dismiss Mr. Coulomb.
