8,404 research outputs found
Theory of plasmonic waves on a chain of metallic nanoparticles in a liquid crystalline host
A chain of metallic particles, of sufficiently small diameter and spacing,
allows linearly polarized plasmonic waves to propagate along the chain. In this
paper, we describes how these waves are altered when the liquid crystal host is
a nematic or a cholesteric liquid crystal (NLC or CLC) with or without an
applied magnetic field. We find that, in general, the liquid crystal host,
either NLC or CLC, alters the dispersion relations of the transverse () and
longitudinal () waves significantly from the dispersion relations for an
isotropic host. We show that by altering the director axis of the liquid
crystal relative to the long axis of the metallic chain, that the branch
can be split into two non-degenerate linearly polarized branches (NLC host) or
two non-degenerate elliptically polarized branches (CLC host). When an external
magnetic field is applied parallel to both the long axis of the metallic
particles and the director of the CLC host, we find that the dispersion
relations are odd in an exchange in sign for for the non-degenerate
elliptically polarized branches. That is, the application of an external
magnetic field leads to the realization of a one-way waveguide.Comment: 9 Pages, 3 Figures. arXiv admin note: text overlap with
arXiv:1210.150
Model of the Longitudinal Spin Seebeck Coefficient of InSb in a Magnetic Field
We develop a simple theory for the longitudinal spin Seebeck effect in
n-doped InSb in an external magnetic field. We consider spin- electrons in
the conduction band of InSb with a temperature gradient parallel to the applied
magnetic field. In the absence of spin-orbit interactions, a Boltzmann equation
approach leads to a spin current parallel to the field and proportional to the
temperature gradient. The calculated longitudinal spin Seebeck coefficients
oscillates as a function of magnetic field B; the peak positions are
approximately periodic in 1/B. The oscillations arise when the Fermi energy
crosses the bottom of a Landau band.Comment: 7 pages, 6 figure
Graphene with adatoms: tuning the magnetic moment with an applied voltage
We show that, in graphene with a small concentration of adatoms, the total
magnetic moment can be switched on and off by varying the Fermi energy
, either by applying a gate voltage or by suitable chemical doping. Our
calculation is carried out using a simple tight-binding model described
previously, combined with a mean-field treatment of the electron-electron
interaction on the adatom. The values of at which the moment is turned on
or off are controlled by the strength of the hopping between the graphene sheet
and the adatom, the on-site energy of the adatom, and the strength of the
electron-electron correlation energy U. Our result is in qualitatively
consistent with recent experiments by Nair {\it et al.} [Nat.\ Commun.\ {\bf
4}, 2010 (2013)].Comment: 4 Pages, 1 Figur
Thermodynamic properties in polynomial form for carbon, hydrogen, nitrogen, and oxygen systems from 300 to 15000 K
Thermodynamic properties in polynomial form for carbon, hydrogen, nitrogen, and oxygen systems form 300 to 15000
Interactions measurement payload for Shuttle
The Interactions Measurement Payload for Shuttle (IMPS) consisted of engineering experiments to determine the effects of the space environment on projected Air Force space systems. Measurements by IMPS on a polar-orbit Shuttle flight will lead to detailed knowledge of the interaction of the low-altitude polar-auroral environment on materials, equipment and technologies to be used in future large, high-power space systems. The results from the IMPS measurements will provide direct input to MIL-STD design guidelines and test standards that properly account for space-environment effects
Optimization of resource allocation can explain the temporal dynamics and honesty of sexual signals
In species in which males are free to dynamically alter their allocation to sexual signaling over the breeding season, the optimal investment in signaling should depend on both a male’s state and the level of competition he faces at any given time. We developed a dynamic optimization model within a game‐theoretical framework to explore the resulting signaling dynamics at both individual and population levels and tested two key model predictions with empirical data on three‐spined stickleback (Gasterosteus aculeatus) males subjected to dietary manipulation (carotenoid availability): (1) fish in better nutritional condition should be able to maintain their signal for longer over the breeding season, resulting in an increasingly positive correlation between nutritional status and signal (i.e., increasing signal honesty), and (2) female preference for more ornamented males should thus increase over the breeding season. Both predictions were supported by the experimental data. Our model shows how such patterns can emerge from the optimization of resource allocation to signaling in a competitive situation. The key determinants of the honesty and dynamics of sexual signaling are the condition dependency of male survival, the initial frequency distribution of nutritional condition in the male population, and the cost of signaling
On the Localization of One-Photon States
Single photon states with arbitrarily fast asymptotic power-law fall-off of
energy density and photodetection rate are explicitly constructed. This goes
beyond the recently discovered tenth power-law of the Hellwarth-Nouchi photon
which itself superseded the long-standing seventh power-law of the Amrein
photon.Comment: 7 pages, tex, no figure
Transport and ageing: Extending quality of life for older people via public and private transport
Accessible public transport and the independence that comes with car driving are generally thought to be linked to quality of life in old age. However, there has been almost no research on this topic in the UK. This study by researchers from the University of Paisley and the University of East London used a multi-method approach to explore the relationship between quality of life and access to public and private transport. The study also examined the extent to which the transport needs of older people are taken into account by transport professionals
Recommended from our members
A Review of Literature on Health-Related Quality of Life of Retinoblastoma Survivors.
Background: Retinoblastoma is a malignant tumor of the eye that typically presents in early childhood and occurs in approximately 1 in 20,000 births. While active treatment of the tumor is typically completed in childhood, survivors often suffer from long-term effects from treatment including visual impairment, facial deformities, and fear of recurrence or secondary cancer. However, little is known how these long-term effects affect their health-related quality of life (HRQOL). Purpose: To review the literature on HRQOL in retinoblastoma survivors. Method: We searched three electronic databases from January 2005 to December 2018 for original research articles reporting on HRQOL or individual domains such as function, cognition, and psychosocial outcomes in retinoblastoma survivors. Results: A total of 59 articles were reviewed and 15 were identified as eligible. Five of the studies reported worse HRQOL in retinoblastoma survivors than controls or general population norms. Parent-proxy ratings were worse than survivors' self-reports. Conclusion: Our findings confirm the need for further HRQOL research to assess the factors influencing long-term outcomes associated with treatment in adolescent and young adult retinoblastoma survivors. By identifying any potential deficits in specific domains of HRQOL, early interventions might be developed to improve HRQOL in retinoblastoma survivors
- …
