1,200 research outputs found
On dynamical net-charge fluctuations within a hadron resonance gas approach
The dynamical net-charge fluctuations () in different particle
ratios , , and are calculated from the hadron resonance
gas (HRG) model and compared with STAR central Au+Au collisions at
GeV and NA49 central Pb+Pb collisions at
GeV. The three charged-particle ratios (,
, and ) are determined as total and average of opposite and
average of same charges. We find an excellent agreement between the HRG
calculations and the experimental measurements, especially from STAR beam
energy scan (BES) program, while the strange particles in the NA49 experiment
at lower Super Proton Synchrotron (SPS) energies are not reproduced by the HRG
approach. We conclude that the utilized HRG version seems to take into
consideration various types of correlations including strong interactions
through the heavy resonances and their decays especially at BES energies.Comment: 8 pages, 1 figure, accepted for publication in Advances in High
Energy Physic
Saturable discrete vector solitons in one-dimensional photonic lattices
Localized vectorial modes, with equal frequencies and mutually orthogonal
polarizations, are investigated both analytically and experimentally in a
one-dimensional photonic lattice with saturable nonlinearity. It is shown that
these modes may span over many lattice elements and that energy transfer among
the two components is both phase and intensity dependent. The transverse
electrically polarized mode exhibits a single-hump structure and spreads in
cascades in saturation, while the transverse magnetically polarized mode
exhibits splitting into a two-hump structure. Experimentally such discrete
vector solitons are observed in lithium niobate lattices for both coherent and
mutually incoherent excitations.Comment: 4 pages, 5 figures (reduced for arXiv
Robust Design of RF-MEMS Cantilever Switches Using Contact Physics Modeling
This paper presents the robust design optimization of an RF-MEMS direct contact cantilever switch for minimum actuation voltage and opening time, and maximum power handling capability. The design variables are the length and thickness of the entire cantilever, the widths of the sections of the cantilever, and the dimple size. The actuation voltage is obtained using a 3-D structural-electrostatic finite-element method (FEM) model, and the opening time is obtained using the same FEM model and the experimental model of adhesion at the contact surfaces developed in our previous work. The model accounts for an unpredictable variance in the contact resistance resulting from the micromachining process for the estimation of the power handling. This is achieved by taking the ratio of the root mean square power of the RF current (signal") passing through the switch to the contact temperature ("noise") resulting from the possible range of the contact resistance. The resulting robust optimization problem is solved using a Strength Pareto Evolutionary Algorithm, to obtain design alternatives exhibiting different tradeoffs among the three objectives. The results show that there exists substantial room for improved designs of RF-MEMS direct-contact switches. It also provides a better understanding of the key factors contributing to the performances of RF-MEMS switches. Most importantly, it provides guidance for further improvements of RF-MEMS switches that exploit complex multiphysics phenomena.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87274/4/Saitou7.pd
Effect of Phacoemulsification on Intraocular Pressure in Eyes with Functioning Tube Shunts
Purpose: To evaluate the effect of phacoemulsification on intraocular pressure (IOP) in eyes with functioning tube shunts.
Methods: This was a retrospective chart review of primary open-angle glaucoma (POAG) patients with a functioning tube who underwent phacoemulsification and had â„24 months of follow-up. The primary end point was defined as surgical failure (IOP > 21 mmHg) at month 24, progression to no light perception (NLP) vision, glaucoma reoperation, or implant removal. Surgical failure defined as IOP >18 and >15 mmHg, changes in visual acuity (VA), IOP, and number of medications were assessed.
Results: Twenty-seven eyes of 27 patients with moderate or severe POAG were included. The mean age of the patients was 64.2 ± 10.8 years. The interval between the tube shunt and phacoemulsification was 28.8 ± 25.0 months. At the end of the study, four (14.8%) eyes met the failure criteria; the average time to failure was 9.3 ± 3.8 months. The causes of failure were high IOP in two (50.0%) and glaucoma reoperation in two (50.0%) eyes; however, no eyes progressed to NLP vision. Surgical failure defined as IOP >18 and >15 mmHg showed an increasing failure rate (18.5% and 48.5%, respectively). The mean IOP and medications number remained stable at month 24 compared to baseline (P = 0.131 and P = 0.302, respectively). Initially, VA showed improvement, with the greatest improvement at 6 months (P = 0.001), but at 24 months the improvement was no longer significant (P = 0.430).
Conclusion: Phacoemulsification in patients with functioning tubes did not change the mean IOP in most of the patients (86.2%); the number of medications also did not increase
Magnetoplasmonic design rules for active magneto-optics
Light polarization rotators and non-reciprocal optical isolators are
essential building blocks in photonics technology. These macroscopic passive
devices are commonly based on magneto-optical Faraday and Kerr polarization
rotation. Magnetoplasmonics - the combination of magnetism and plasmonics - is
a promising route to bring these devices to the nanoscale. We introduce design
rules for highly tunable active magnetoplasmonic elements in which we can
tailor the amplitude and sign of the Kerr response over a broad spectral range
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