8,524 research outputs found
Conversion efficiency and luminosity for gamma-proton colliders based on the LHC-CLIC or LHC-ILC QCD Explorer scheme
Gamma-proton collisions allow unprecedented investigations of the low x and
high regions in quantum chromodynamics. In this paper, we investigate
the luminosity for "ILC"LHC ( TeV) and
"CLIC"LHC ( TeV) based colliders. Also
we determine the laser properties required for high conversion efficiency.Comment: 16, 6 figure
Enhanced charge stripe order of superconducting La(2-x)Ba(x)CuO(4) in a magnetic field
The effect of a magnetic field on the charge stripe order in
La(2-x)Ba(x)CuO(4) has been studied by means of high energy (100 keV) x-ray
diffraction for charge carrier concentrations ranging from strongly underdoped
to optimally doped. We find that charge stripe order can be significantly
enhanced by a magnetic field applied along the c-axis, but only at temperatures
and dopings where it coexists with bulk superconductivity at zero field. The
field also increases stripe correlations between the planes, which can result
in an enhanced frustration of the interlayer Josephson coupling. Close to the
famous x=1/8 compound, where zero field stripe order is pronounced and bulk
superconductivity is suppressed, charge stripe order is independent of a
magnetic field. The results imply that static stripe order and
three-dimensionally coherent superconductivity are competing ground states.Comment: 6 pages, 4 figure
Linking complexity economics and systems thinking, with illustrative discussions of urban sustainability
The expanding research of complexity economics has been signalling its preference for a formal quantitative investigation of diverse interactions between heterogeneous agents at the lower, micro-level resulting in emergent, realistic socioeconomic dynamics at the higher, macro-level. However, there is scarcity in research that explicitly links complexity perspectives in economics with the systems thinking literature, despite these being highly compatible, with strong connections and common historical traces. We aim to address this gap by exploring commonalities and differences between the two bodies of knowledge, seen particularly through an economics lens. We argue for a hybrid approach, in that agent-based complexity perspectives in economics could more closely connect to two main systems thinking attributes: a macroscopic approach to analytically capturing the complex dynamics of systems, and an inter-subjective interpretivist dimension, when investigating complex social-economic order. Illustrative discussions of city sustainability are provided, with an emphasis on decarbonisation and residential energy demand aspects
Convection in nanofluids with a particle-concentration-dependent thermal conductivity
Thermal convection in nanofluids is investigated by means of a continuum
model for binary-fluid mixtures, with a thermal conductivity depending on the
local concentration of colloidal particles. The applied temperature difference
between the upper and the lower boundary leads via the Soret effect to a
variation of the colloid concentration and therefore to a spatially varying
heat conductivity. An increasing difference between the heat conductivity of
the mixture near the colder and the warmer boundary results in a shift of the
onset of convection to higher values of the Rayleigh number for positive values
of the separation ratio psi>0 and to smaller values in the range psi<0. Beyond
some critical difference of the thermal conductivity between the two
boundaries, we find an oscillatory onset of convection not only for psi<0, but
also within a finite range of psi>0. This range can be extended by increasing
the difference in the thermal conductivity and it is bounded by two
codimension-2 bifurcations.Comment: 13 pages, 11 figures; submitted to Physical Review
Anisotropic effect of field on the orthorhombic-to-tetragonal transition in the striped cuprate (La,Nd)_{2-x}Sr_xCuO_4
The Nd-doped cuprate La_{2-y-x}Nd_ySr_xCuO_4 displays a first-order phase
transition at T_d (= 74 K for x=0.10, y = 0.60) to a low-temperature tetragonal
(LTT) phase. A magnetic field H applied || the a-axis leads to an increase in
T_d, whereas T_d is decreased when H || c. These effects show that magnetic
ordering involving both Nd and Cu spins plays a key role in driving the LTO-LTT
transition. Related anisotropic effects are observed in the uniform
susceptibility and the in-plane magnetoresistance.Comment: 5 pages, 5 figure
A joint view on genetic variants for adiposity differentiates subtypes with distinct metabolic implications.
The problem of the genetics of related phenotypes is often addressed by analyzing adjusted-model traits, but such traits warrant cautious interpretation. Here, we adopt a joint view of adiposity traits in ~322,154 subjects (GIANT consortium). We classify 159 signals associated with body mass index (BMI), waist-to-hip ratio (WHR), or WHR adjusted for BMI (WHRadjBMI) at P < 5 × 10 <sup>-8</sup> , into four classes based on the direction of their effects on BMI and WHR. Our classes help differentiate adiposity genetics with respect to anthropometry, fat depots, and metabolic health. Class-specific Mendelian randomization reveals that variants associated with both WHR-decrease and BMI increase are linked to metabolically rather favorable adiposity through beneficial hip fat. Class-specific enrichment analyses implicate digestive systems as a pathway in adiposity genetics. Our results demonstrate that WHRadjBMI variants capture relevant effects of "unexpected fat distribution given the BMI" and that a joint view of the genetics underlying related phenotypes can inform on important biology
Commensurate-Incommensurate transition in the melting process of the orbital ordering in Pr0.5Ca0.5MnO3: neutron diffraction study
The melting process of the orbital order in
Pr0.5Ca0.5MnO3 single crystal has been studied in detail as a function of
temperature by neutron diffraction. It is demonstrated that a
commensurate-incommensurate (C-IC) transition of the orbital ordering takes
place in a bulk sample, being consistent with the electron diffraction studies.
The lattice structure and the transport properties go through drastic changes
in the IC orbital ordering phase below the charge/orbital ordering temperature
Tco/oo, indicating that the anomalies are intimately related to the partial
disordering of the orbital order, unlike the consensus that it is related to
the charge disordering process. For the same T range, partial disorder of the
orbital ordering turns on the ferromagnetic spin fluctuations which were
observed in a previous neutron scattering study.Comment: 5 pages, 2 figures, REVTeX, to be published in Phys. Rev.
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