11,672 research outputs found
Hydrogen reliquefiers for lunar storage systems
Reliquifier application to eliminate propellant boil off losses in space and lunar storage system
Enhanced Andreev reflection in gapped graphene
We theoretically demonstrate unusual features of superconducting proximity
effect in gapped graphene which presents a pseudospin symmetry-broken
ferromagnet with a net pseudomagnetization. We find that the presence of a band
gap makes the Andreev conductance of graphene superconductor/pseudoferromagnet
(S/PF) junction to behave similar to that of a graphene
ferromagnet-superconductor junction. The energy gap enhance the
pseudospin inverted Andreev conductance of S/PF junction to reach a limiting
maximum value for , which depending on the bias voltage can be
larger than the value for the corresponding junction with no energy gap. We
further demonstrate a damped-oscillatory behavior for the local density of
states of the PF region of S/PF junction and a long-range crossed Andreev
reflection process in PF/S/PF structure with antiparallel alignment of
pseudomagnetizations of PFs, which confirm that, in this respect, the gapped
normal graphene behaves like a ferromagnetic graphene.Comment: 7.2 pages, 5 figures, accepted for publication in Phys. Rev.
Comment on "Competition between helimagnetism and commensurate quantum spin correlations in LiCu2O2"
The microscopic origin of the recently observed helical structure in LiCu2O2
[1] is considered. It is shown that the frustrated antiferromagnetic double
chain scenario adopted in Ref.1 is unrealistic. It should be replaced by a
frustrated single-chain (CuO2) scenario proposed in Ref. 2 with ferromagnetic
nearest neighbor and antiferromagnetic next nearest neighbor exchange integrals
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[1] T. Masuda et al. Phys. Rev. Lett. 92 (2004), 177201. [2] A. Gippius et
al. Phys. Rev. B 70 (2004), R01426; cond-mat/0312576.Comment: one page, one figur
Global Warming: Global Warning for Local Actions
After decades of global warming many are still in the dark as what needs to bedone to overcome this world threat that affects single citizen of the planet earth. The word ‘sustainability' has been used very loosely, some not knowing the exact meaning of it only with intentions to gain research grant for the academics, profit making by keeping by the general business environment, thus leading to dumping the market with green-washing products. Those who seriously know the true meaning are not many and many times frustrated with the doings of the many which do not. This presentation hopefully providesome useful insights as to what sustainability means and for the necessary green initiatives that need to be taken to reduce further aggravation of the borderless geographical environment. Future growth in all countries are converging into a common trend and therefore efforts need to be in tandem and synchronized for a more effective win against this pervasive war of the world. Most tangible efforts are normally easily observed in the socio economic trend that affects the built environment of individual countries. The commoncues of the world are that it is getting hot, flat and crowded and to overcome this force is no easy task for any nation since the rhythm and tempo of growth of each nation differs. But one thing is common, that the rate of urbanization is rapid throughout the world. It was reported that by about 2030 the land-use for urbanization will be about 75% all over the world and so a relook at the socio economic policies must be geared towards how urbanization do not worsen the already bad situation from global warming
Hematocrit Level on Blood flow through a Stenosed Artery with Permeable Wall: A Theoretical Study
The paper deals with the hematocrit level on resistance of flow, wall shear stress in a stenosed artery of permeable wall. In the paper we have developed and solved some theoretical formulas based on stenosis and hematocrit effects. The results highlight that the resistance of flow increases for increasing of stenosis height where the hematocrit level (35%-45%) has significant effects. Moreover, the effects of slip parameter and Darcy number due to permeability of the wall on resistance of flow have been investigated. The effects of hematocrit level, slip parameter and Darcy number have been focused on wall shear stress of the permeable inner surface of the artery which has a fashion of downwardly concave for increasing of the z-axis of the artery
Identifications and SEDs of the detected sources from the AKARI Deep Field South
In order to find counterparts of the detected objects in the AKARI Deep Field
South (ADFS) in all available wavelengths, we searched public databases (NED,
SIMBAD and others). Checking 500 sources brighter than 0.0482 Jy in the AKARI
Wide-S band, we found 114 sources with possible counterparts, among which 78
were known galaxies. We present these sources as well as our first attempt to
construct spectral energy distributions (SEDs) for the most secure and most
interesting sources among them, taking into account all the known data together
with the AKARI measurements in four bands.Comment: 4 pages, 10 figures, To appear in: the proceedings of the conference
"AKARI, a light to illuminate the misty Universe", February 16-19 2009, Toky
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