Enhancing the Radiative Rate in III-V Semiconductor Plasmonic Core-Shell Nanowire Resonators

We investigate the radiative properties of plasmonic core-shell nanowire resonators and, using boundary element method calculations, demonstrate enhanced radiative decay rate by up to 3500 times in nanoscale compound semi-conductor/metal cavities. Calculation of the local density of optical states enables identification of new types of modes in cavities with mode volumes on the order of 10^(-4)(λ/n)^3. These modes dramatically enhance the radiative decay rate and significantly modify the polarization of far-field emission

Complications and Predictors of Need for Return to the Operating Room in the Treatment of Supracondylar Humerus Fractures in Children

Supracondylar humerus fractures are common pediatric injuries. Little is known about the risk factors for repeat operative procedures. A retrospective chart review of 709 patients treated for a displaced supracondylar humerus fracture was performed to identify risk factors for return to the operating room during the initial post-operative period. Deviations of routine fracture care were recorded and complication rates were compared between Gartland type 2 and 3 fractures using logistic regression. Type 3 fractures were found to have a higher complication rate, and, specifically, more peri-operative nerve palsies, more likely to need to return to the operating room for hardware removal, to lose fracture reduction, and require a return to the operating room for any reason. Five risk factors which may require returning to the operating room were identified: younger patient age, left sided fractures, type 3 fractures, peri-operative nerve palsy, and post-operative infection. In conclusion, Gartland type 3 supracondylar humerus fractures are associated with more complications then type 2 fractures. Risk factors for the need to return to the operating room in the post-operative period include: younger patient age, left sided fractures, type 3 fractures, peri-operative nerve palsy, and post-operative infection. Patients with these risk factors should be considered at risk for return to the OR and fracture fixation and follow up protocols should be adjusted for this risk

Local density of states, spectrum, and far-field interference of surface plasmon polaritons probed by cathodoluminescence

The surface plasmon polariton (SPP) field intensity in the vicinity of gratings patterned in an otherwise planar gold surface is spatially resolved using cathodoluminescence (CL). A detailed theoretical analysis is presented that successfully explains the measured CL signal based upon interference of transition radiation directly generated by electron impact and SPPs launched by the electron and outcoupled by the grating. The measured spectral dependence of the SPP yield per incoming electron is in excellent agreement with rigorous electromagnetic calculations. The CL emission is shown to be similar to that of a dipole oriented perpendicular to the surface and situated at the point of electron impact, which allows us to establish a solid connection between the CL signal and the photonic local density of states associated to the SPPs

International Chemical Congresses.

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Geochronology of the middle Eocene Purple Bench locality (Devil’s Graveyard Formation), Trans-Pecos Texas, USA

Purple Bench is a middle Eocene fossil locality in the Devil’s Graveyard Formation of the Trans-Pecos region of West Texas. In addition to yielding a range of taxa characteristic of the Uintan North American Land Mammal Age, the Purple Bench locality is noteworthy in documenting a number of endemic species that are known only from the site. Despite the Uintan character of the mammalian fauna, the absolute age of Purple Bench is a matter of debate. This uncertainty stems from the wide interval of time encompassed by current radiometric dates bracketing the Purple Bench locality and from conflicting magnetostratigraphic correlations in the Devil’s Graveyard Formation. This study constrains the absolute age of the Purple Bench locality through detrital zircon U-Pb geochronological analyses. For these analyses, 147 new detrital zircon U-Pb ages were collected from five tuffaceous sandstones and reworked tuff horizons and analyzed via Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICPMS). These new detrital zircon U-Pb geochronological analyses suggest a maximum depositional age of 43.7 +0.8 / -0.2 Ma for the Purple Bench tuff, a significant marker horizon immediately below the Purple Bench locality. These new maximum depositional age dates presented here provide constraints on the true depositional age of the lower and middle members of the Devil’s Graveyard Formation, bringing clarity to the previously ambiguous age of the fossil-bearing Purple Bench locality. The age constraints presented here also aid the characterization of the temporally and spatially variable Uintan North American Land Mammal Age

Surface plasmon polariton modes in a single-crystal Au nanoresonator fabricated using focused-ion-beam milling

We use focused-ion-beam milling of a single-crystal Au surface to fabricate a 590-nm-long linear ridge that acts as a surface plasmon nanoresonator. Cathodoluminescence imaging spectroscopy is then used to excite and image surface plasmons on the ridge. Principal component analysis reveals distinct plasmonic modes, which proves confinement of surface-plasmon oscillations to the ridge. Boundary-element-method calculations confirm that a linear ridge is able to support highly-localized surface-plasmon modes (mode diameter < 100 nm). The results demonstrate that focused-ion-beam milling can be used in rapid prototyping of nanoscale single-crystal plasmonic components.Comment: 4 pages, 4 figure

A novel, aerosol-nanocrystal floating-gate device for non-volatile memory applications

This paper describes the fabrication, and structural and electrical characterization of a new, aerosol-nanocrystal floating-gate FET, aimed at non-volatile memory (NVM) applications. This aerosol-nanocrystal NVM device features program/erase characteristics comparable to conventional stacked gate NVM devices, excellent endurance (>l0^5 P/E cycles), and long-term non-volatility in spite of a thin bottom oxide (55-60Å). In addition, a very simple fabrication process makes this aerosol-nanocrystal NVM device a potential candidate for low cost NVM applications

Autonomous Bursting in a Homoclinic System

A continuous train of irregularly spaced spikes, peculiar of homoclinic chaos, transforms into clusters of regularly spaced spikes, with quiescent periods in between (bursting regime), by feeding back a low frequency portion of the dynamical output. Such autonomous bursting results to be extremely robust against noise; we provide experimental evidence of it in a CO2 laser with feedback. The phenomen here presented display qualitative analogies with bursting phenomena in neurons.Comment: Submitted to Phys. Rev. Lett., 14 pages, 5 figure

Ultraefficient Thermophotovoltaic Power Conversion By Band-Edge Spectral Filtering

Thermophotovoltaic power conversion utilizes thermal radiation from a local heat source to generate electricity in a photovoltaic cell. It was shown in recent years that the addition of a highly reflective rear mirror to a solar cell maximizes the extraction of luminescence. This, in turn, boosts the voltage, enabling the creation of record-breaking solar efficiency. Now we report that the rear mirror can be used to create thermophotovoltaic systems with unprecedented high thermophotovoltaic efficiency. This mirror reflects low-energy infrared photons back into the heat source, recovering their energy. Therefore, the rear mirror serves a dual function; boosting the voltage and reusing infrared thermal photons. This allows the possibility of a practical \u3e50% efficient thermophotovoltaic system. Based on this reflective rear mirror concept, we report a thermophotovoltaic efficiency of 29.1 ± 0.4% at an emitter temperature of 1,207 °C