69 research outputs found
The Criminal Justice Act - 1964 To 1976
Colloquium: The Federal Judiciary: Essays from the Benc
The Criminal Justice Act - 1964 To 1976
Colloquium: The Federal Judiciary: Essays from the Benc
Neel Temperature for Quasi-Two-Dimensional Dipolar Antiferromagnets
We calculate the N\'eel temperature for two-dimensional isotropic
dipolar Heisenberg antiferromagnets via linear spin-wave theory and a high
temperature expansion, employing the method of Callen. The theoretical
predictions for for KMnF, RbMnF, RbMnCl and
(CHNH)MnCl are in good agreement with the measured values.Comment: 12 pages, REVTEX, TUM-CP-93-0
The effect of magnetic dipolar interactions on the interchain spin wave dispersion in CsNiF_3
Inelastic neutron scattering measurements were performed on the ferromagnetic
chain system CsNiF_3 in the collinear antiferromagnetic ordered state below T_N
= 2.67K. The measured spin wave dispersion was found to be in good agreement
with linear spin wave theory including dipolar interactions. The additional
dipole tensor in the Hamiltonian was essential to explain some striking
phenomena in the measured spin wave spectrum: a peculiar feature of the
dispersion relation is a jump at the zone center, caused by strong dipolar
interactions in this system. The interchain exchange coupling constant and the
planar anisotropy energy were determined within the present model to be J'/k_B
= -0.0247(12)K and A/k_B = 3.3(1)K. This gives a ratio J/J' \approx 500, using
the previously determined intrachain coupling constant J/k_B = 11.8$. The small
exchange energy J' is of the same order as the dipolar energy, which implies a
strong competition between the both interactions.Comment: 18 pages, TeX type, 7 Postscript figures included. To be published in
Phys. Rev.
Nanoscale Phenomenology from Visualizing Pair Formation Experiment
Recently, Gomes et al. [1] have visualized the gap formation in nanoscale
regions (NRs) above the critical temperature T_c in the high-T_c superconductor
Bi_2Sr_2CaCu_2O_{8+\delta}. It has been found that, as the temperature lowers,
the NRs expand in the bulk superconducting state consisted of inhomogeneities.
The fact that the size of the inhomogeneity [2] is close to the minimal size of
the NR [1] leads to a conclusion that the superconducting phase is a result of
these overlapped NRs. In the present paper we perform the charge and
percolation regime analysis of NRs and show that at the first critical doping
x_{c1}, when the superconductivity starts on, each NR carries the positive
electric charge one in units of electron charge, thus we attribute the NR to a
single hole boson, and the percolation lines connecting these bosons emerge. At
the second critical doping x_{c2}, when the superconductivity disappears, our
analysis demonstrates that the charge of each NR equals two. The origin of
x_{c2} can be understood by introducing additional normal phase hole fermions
in NRs, whose concentration appearing above x_{c1} increases smoothly with the
doping and breaks the percolation lines of bosons at x_{c2}. The last one
results in disappearing the bulk bosonic property of the pseudogap (PG) region,
which explains the upper bound for existence of vortices in Nernst effect [3].
Since [1] has demonstrated the absence of NRs at the PG boundary one can
conclude that along this boundary, as well as in x_{c2}, all bosons disappear.Comment: 4 pages, 1 figure. Good quality figure one can find in published
journal paper. Added 4 new references. Section of arXiv: 1010.043
Influence of climatic variables on crown condition in pine forests of Northern Spain
Producción CientíficaThe aim of this study was to find relationships between crown condition and
some climatic parameters to identify which are those having a main influence on
crown condition, and how this influence is shown in the tree (crown transparency),
and to contribute to the understanding of how these parameters will affect under
future climate change scenarios
Limitations of Water Resources Infrastructure for Reducing Community Vulnerabilities to Extremes and Uncertainty of Flood and Drought
Debate and deliberation surrounding climate change has shifted from mitigation toward adaptation, with much of the adaptation focus centered on adaptive practices, and infrastructure development. However, there is little research assessing expected impacts, potential benefits, and design challenges that exist for reducing vulnerability to expected climate impacts. The uncertainty of design requirements and associated government policies, and social structures that reflect observed and projected changes in the intensity, duration, and frequency of water-related climate events leaves communities vulnerable to the negative impacts of potential flood and drought. The results of international research into how agricultural infrastructure features in current and planned adaptive capacity of rural communities in Argentina, Canada, and Colombia indicate that extreme hydroclimatic events, as well as climate variability and unpredictability are important for understanding and responding to community vulnerability. The research outcomes clearly identify the need to deliberately plan, coordinate, and implement infrastructures that support community resiliency.Fil: McMartin, Dena W.. University of Regina; CanadáFil: Hernani Merino, Bruno H.. University of Regina; CanadáFil: Bonsal, Barrie. Environment Canada; CanadáFil: Hurlbert, Margot. University of Regina; CanadáFil: Villalba, Ricardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Regional de Investigaciones Cientifícas y Tecnológicas; ArgentinaFil: Ocampo, Olga L.. Universidad Autónoma de Manizales; ColombiaFil: Upegui, Jorge Julián Vélez. Universidad Nacional de Colombia; ColombiaFil: Poveda, Germán. Universidad Nacional de Colombia; ColombiaFil: Sauchyn, David J.. University of Regina; Canad
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