1,086 research outputs found
Universal Fluctuations of the Danube Water Level: a Link with Turbulence, Criticality and Company Growth
A global quantity, regardless of its precise nature, will often fluctuate
according to a Gaussian limit distribution. However, in highly correlated
systems, other limit distributions are possible. We have previously calculated
one such distribution and have argued that this function should apply
specifically, and in many instances, to global quantities that define a steady
state. Here we demonstrate, for the first time, the relevance of this
prediction to natural phenomena. The river level fluctuations of the Danube are
observed to obey our prediction, which immediately establishes a generic
statistical connection between turbulence, criticality and company growth
statistics.Comment: 5 pages, 1 figur
Low-temperature muon spin rotation studies of the monopole charges and currents in Y doped Ho2Ti2O7
In the ground state of Ho2Ti2O7 spin ice, the disorder of the magnetic moments follows the same rules as the proton disorder in water ice. Excitations take the form of magnetic monopoles that interact via a magnetic Coulomb interaction. Muon spin rotation has been used to probe the low-temperature magnetic behaviour in single crystal Ho2−xYxTi2O7 (x = 0, 0.1, 1, 1.6 and 2). At very low temperatures, a linear field dependence for the relaxation rate of the muon precession λ(B), that in some previous experiments on Dy2Ti2O7 spin ice has been associated with monopole currents, is observed in samples with x = 0, and 0.1. A signal from the magnetic fields penetrating into the silver sample plate due to the magnetization of the crystals is observed for all the samples containing Ho allowing us to study the unusual magnetic dynamics of Y doped spin ice
Anisotropic Release of the Residual Zero-point Entropy in the Spin Ice Compound Dy2Ti2O7: Kagome-ice Behavior
We report the specific heat and entropy of single crystals of the spin ice
compound Dy2Ti2O7 at temperatures down to 0.35 K. We apply magnetic fields
along the four characteristic directions: [100], [110], [111] and [112].
Because of Ising anisotropy, we observe anisotropic release of the residual
zero-point entropy, attributable to the difference in frustration
dimensionality. In the high magnetic field along these four directions, the
residual entropy is almost fully released and the activation entropy reaches
Rln2. However, in the intermediate field region, the entropy in fields along
the [111] direction is different from those for the other three field
directions. For the [111] direction the frustration structure changes from that
of three-dimensional(3D) pyrochlore to that of two-dimensional(2D) Kagome-like
lattice with constraint due to the ice rule, leading to different values of
zero-point entropy.Comment: 4 pages, 4 figures, to appear in Phys. Rev.
Low Temperature Spin Freezing in Dy2Ti2O7 Spin Ice
We report a study of the low temperature bulk magnetic properties of the spin
ice compound Dy2Ti2O7 with particular attention to the (T < 4 K) spin freezing
transition. While this transition is superficially similar to that in a spin
glass, there are important qualitative differences from spin glass behavior:
the freezing temperature increases slightly with applied magnetic field, and
the distribution of spin relaxation times remains extremely narrow down to the
lowest temperatures. Furthermore, the characteristic spin relaxation time
increases faster than exponentially down to the lowest temperatures studied.
These results indicate that spin-freezing in spin ice materials represents a
novel form of magnetic glassiness associated with the unusual nature of
geometrical frustration in these materials.Comment: 24 pages, 8 figure
Doxorubicin-Based Chemotherapy for the Palliative Treatment of Adult Patients with Locally Advanced or Metastatic Soft-Tissue Sarcoma: A Meta-Analysis and Clinical Practice Guideline
Purpose. To make recommendations for the use of doxorubicin-based
chemotherapy in patients with soft-tissue sarcoma
Comment on "Short-range magnetic interactions in the spin-ice compound Ho2Ti2O7"
In their recent communication (Phys. Rev. B 64, 060406(R) (2001)) Cornelius
and Gardner have reported the results of magnetization and susceptibility
studies on single crystals of the pyrochlore Ho2Ti2O7. The observed field
dependence of magnetization is totally unexpected, as it seems to suggest that
the magnetic moments in this compound do not obey the 'ice-rule'. We have
re-measured the magnetization curves for Ho2Ti2O7 single crystal for the three
principal directions of an applied magnetic field and found nearly perfect
agreement with the predictions for a nearest-neighbor spin-ice model.Comment: comment on Phys. Rev. B 64, 060406(R) (2001
Metastatic Secondary Fibrosarcoma of Bone Responsive to Repeated Courses of Ifosfamide and Associated With Hypoglycemia
We present a case of a 40-year-old man with secondary fibrosarcoma of bone, arising from a non-ossifying fibroma. He
subsequently developed metastatic disease that responded to four successive chemotherapy courses, the last three using the
same dose/schedule of single agent ifosfamide. Eventual rapid progression of a huge intra-abdominal mass was associated
with the syndrome of extrapancreatic tumour hypoglycemia (EPTH). The clinicopathological behaviour of fibrosarcoma of
bone, and the mechanism of EPTH are discussed
Low-temperature magnetism in the honeycomb systems SrLn2O4
Recent progress in the understanding of the complex magnetic properties of
the family of rare-earth strontium oxides, SrLn2O4, is reviewed. These
compounds consisting of hexagons and triangles are affected by geometrical
frustration and therefore exhibit its characteristic features, such as a
significant reduction of magnetic ordering temperatures and complex phase
diagrams in an applied field. Some of the observed features appear to be rather
remarkable even in the context of the unusual behavior associated with
geometrically frustrated magnetic systems. Of particular interest is the
coexistence at the lowest temperature of different magnetic structures
(exhibiting either long or short-range order) characterized by different
propagation vectors in materials without significant chemical or structural
disorder.Comment: Review Articl
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