3,439 research outputs found
Collapse Of The G D3+ Esr Fine Structure Throughout The Coherent Temperature Of The Gd-doped Kondo Semiconductor Cef E4 P12
Recent experiments on Gd3+ electron-spin resonance (ESR) in the filled skutterudite Ce1-xGdxFe4P12(xâ0.001), at temperatures where the host resistivity manifests a smooth insulator-metal crossover, provide evidence of the underlying Kondo physics associated with this system. At low temperatures (below Tâ160 K), Ce1-xGdxFe4P12 behaves as a Kondo insulator with a relatively large hybridization gap, and the Gd3+ ESR spectra display a fine structure with Lorentzian line shape, typical of insulating media. In this work, based on previous experiments performed by the same group, we argue that the electronic gap may be attributed to the large hybridization present in the coherent regime of a Kondo lattice. Moreover, mean-field calculations suggest that the electron-phonon interaction is fundamental at explaining such hybridization. The resulting electronic structure is strongly temperature dependent, and at Tââ160K the system undergoes an insulator-to-metal transition induced by the withdrawal of 4f electrons from the Fermi volume, the system becoming metallic and nonmagnetic. The Gd3+ ESR fine structure coalesces into a single Dysonian resonance, as in metals. Our simulations suggest that exchange narrowing via the usual Korringa mechanism is not enough to describe the thermal behavior of the Gd3+ ESR spectra in the entire temperature region (4.2-300 K). We propose that the temperature activated fluctuating valence of the Ce ions is the key ingredient that fully describes this unique temperature dependence of the Gd3+ ESR fine structure. © 2016 American Physical Society.942
Using LDGM Codes and Sparse Syndromes to Achieve Digital Signatures
In this paper, we address the problem of achieving efficient code-based
digital signatures with small public keys. The solution we propose exploits
sparse syndromes and randomly designed low-density generator matrix codes.
Based on our evaluations, the proposed scheme is able to outperform existing
solutions, permitting to achieve considerable security levels with very small
public keys.Comment: 16 pages. The final publication is available at springerlink.co
An important role for Myb-MuvB and its target gene KIF23 in a mouse model of lung adenocarcinoma
The conserved Myb-MuvB (MMB) multiprotein complex has an important role in transcriptional activation of mitotic genes. MMB target genes are overexpressed in several different cancer types and their elevated expression is associated with an advanced tumor state and a poor prognosis. This suggests that MMB could contribute to tumorigenesis by mediating overexpression of mitotic genes. However, although MMB has been extensively characterized biochemically, the requirement for MMB in tumorigenesis in vivo has not been investigated. Here we demonstrate that MMB is required for tumor formation in a mouse model of lung cancer driven by oncogenic K-RAS. We also identify a requirement for the mitotic kinesin KIF23, a key target gene of MMB, in tumorigenesis. RNA interference-mediated depletion of KIF23 inhibited lung tumor formation in vivo and induced apoptosis in lung cancer cell lines. Our results suggest that inhibition of KIF23 could be a strategy for treatment of lung cancer
Use cases for Internet of Things (IoT) in the construction sector: Lessons from leading industries
This study conducts a cross-sectoral comparative analysis of academic and industry literature to determine the use cases of the internet of things (IoT). Specifically, the research seeks to explore digital applications (e.g., building information modeling (BIM), radio frequency identification (RFID)) within the construction supply chain â a sector berated for its lack of innovation. An interpretivist epistemological lens provides the overarching methodological approach adopted in which the literature constitutes units of analysis. Ensuing discussion defines the architecture of proposed real-life scenarios and provides a description of an IoT layout for these scenarios. In practical terms, the study contributes to the field by raising awareness of potential use cases of IoT for construction practitioners as âproof of conceptsâ. For researchers, the findings provide a blueprint template layout of suggested use cases to be tested in future research studies hence, offering a sound basis and a fertile ground for advancing the body of knowledge on this topic area
Time series analysis of long term palaeoecological records for the understanding climate change impacts on vegetal ecosystems
Manejo de datos paleoplinolĂłgicos a escala europea para generaciĂłn de modelos climĂĄticos continentale
Self-consistent anisotropic oscillator with cranked angular and vortex velocities
The Kelvin circulation is the kinematical Hermitian observable that measures
the true character of nuclear rotation. For the anisotropic oscillator, mean
field solutions with fixed angular momentum and Kelvin circulation are derived
in analytic form. The cranking Lagrange multipliers corresponding to the two
constraints are the angular and vortex velocities. Self-consistent solutions
are reported with a constraint to constant volume.Comment: 12 pages, LaTex/RevTex, Phys. Rev. C4
Proton-neutron quadrupole interactions: an effective contribution to the pairing field
We point out that the proton-neutron energy contribution, for low multipoles
(in particular for the quadrupole component), effectively renormalizes the
strength of the pairing interaction acting amongst identical nucleons filling
up a single-j or a set of degenerate many-j shells. We carry out the
calculation in lowest-order perturbation theory. We perform a study of this
correction in various mass regions. These results may have implications for the
use of pairing theory in medium-heavy nuclei and for the study of pairing
energy corrections to the liquid drop model when studying nuclear masses.Comment: 19 pages, TeX, 3 tables, 2 figures. Accepted in PR
Cold atoms in videotape micro-traps
We describe an array of microscopic atom traps formed by a pattern of
magnetisation on a piece of videotape. We describe the way in which cold atoms
are loaded into one of these micro-traps and how the trapped atom cloud is used
to explore the properties of the trap. Evaporative cooling in the micro-trap
down to a temperature of 1 microkelvin allows us to probe the smoothness of the
trapping potential and reveals some inhomogeneity produced by the magnetic
film. We discuss future prospects for atom chips based on microscopic
permanent-magnet structures.Comment: Submitted for EPJD topical issue "Atom chips: manipulating atoms and
molecules with microfabricated structures
Cigarette Smoking Increases the Risk of Root Canal Treatment
Few studies have investigated smoking as a risk factor for root canal treatment. We studied the effect of smoking on the incidence of root canal treatment, controlling for recognized risk factors, in 811 dentate male participants in the VA Dental Longitudinal Study. Participants were not VA patients. Follow-up ranged from 2 to 28 years. Root canal treatment was verified on radiographs and evaluated with proportional hazards regression models. Compared with never-smokers, current cigarette smokers were 1.7 times as likely to have root canal treatment (p < 0.001), but cigar and/or pipe use was not significantly associated with root canal treatment. The risk among cigarette smokers increased with more years of exposure and decreased with length of abstinence. These findings suggest that there is a dose-response relationship between cigarette smoking and the risk of root canal treatment
From Feshbach-Resonance Managed Bose-Einstein Condensates to Anisotropic Universes: Some Applications of the Ermakov-Pinney equation with Time-Dependent Nonlinearity
In this work we revisit the topic of two-dimensional Bose-Einstein
condensates under the influence of time-dependent magnetic confinement and
time-dependent scattering length. A moment approach reduces the examination of
moments of the wavefunction (in particular, of its width) to an Ermakov-Pinney
(EP) ordinary differential equation (ODE). We use the well-known structure of
the solutions of this nonlinear ODE to ``engineer'' trapping and interatomic
interaction conditions that lead to condensates dispersing, breathing or even
collapsing. The advantage of the approach is that it is fully tractable
analytically, in excellent agreement with our numerical observations. As an
aside, we also discuss how similar time-dependent EP equations may arise in the
description of anisotropic scalar field cosmologies.Comment: 9 pages, 4 figure
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