Abstmct-Crosstalk due to material absorption in a twowaveguide, symmetric directional coupler switch is investigated. In a material with absorption, it is not possible to completely eliminate the crosstalk by adjusting the coupling length. The coupling length for minimum crosstalk differs from that of lossless systems. Theoretical limits of the lowest achievable crosstalk and the corresponding coupling lengths are calculated. The results show that the effect of absorption on crosstalk is more severe when the devices are designed for low crosstalk. The increase in crosstalk due to absorption can be as high as 20 dB. The material absorption is thus a critical parameter in designing low crosstalk devices.
Two different kinds of n-type GaN films were prepared by organometallic vapor phase epitaxy, one by using trimethylgallium (TMGa) and another by using triethylgallium (TEGa) as the alkyl source. Schottky diodes with well-behaved current–voltage and capacitance–voltage characteristics were fabricated. Deep-level transient spectroscopy studies were performed on these samples. Three distinct deep levels, labeled E1, E2, and E3, were measured in the film grown with TMGa, with an activation energy of 0.14, 0.49, and 1.63±0.3 eV, respectively. Only one level, E3, was observed in the film prepared with TEGa.
Triamcinolone acetonide (TA) is classified as an S9 glucocorticoid in the 2014 Prohibited List published by the World Anti-Doping Agency, which caused it to be prohibited in-competition when administered orally, intravenously, intramuscularly or rectally. The Minimum Required Performance Level (MRPL) for the detection and identification of glucocorticoids is 30 ng/mL. Other common local injection routes, such as intraarticular, intratendinous, or intrabursal injection, are not prohibited. The purpose of this study was to analyze the TA and triamcinolone (T) concentrations in urine after a single injection of TA in patients to determine if it would produce a positive result. This study was performed on 40 patients with sports injuries or joint pains. TA was administered locally (doses varied from 12 to 80 mg). Samples were extracted using a solid-phase extraction column, followed by hydrolysis and liquid extraction using diethyl ether. The elution solvents were collected and dried. The dried residue was reconstituted and assayed by performing liquid chromatography-tandem mass spectrometry (LC-MS/MS) in positive ionization mode using electrospray ionization and multiple-reaction monitoring as the acquisition mode. The results demonstrated that the concentrations of both TA and T in urine exceeded the MRPL (30 ng/mL) after a single local injection. We obtained positive results for TA in 25 patients, and a positive result for T in one patient. Furthermore, the metabolic situation of TA, a long-acting glucocorticoid, was not an exact linear model. The highest concentrations of TA and T appeared 1-4h after injection. This information could be useful for limiting the misuse of TA by athletes. We suggest that athletes be aware when using TA injections during a competition period and obtain approval for therapeutic use exemption prior to using TA.
Engineering thermal emission using micro/nanostructures has received growing attention in recent years. A variety of novel coherent, directional, polarized and narrowband thermal light sources as well as wavelength selective emitters have been proposed and investigated. These emitters show a great potential in applications like thermophotovoltaics, solar energy concentration, radiative cooling, thermal detection, sensing, thermal camouflage, thermal rectification, etc. In this article, we give a review on the use of micro/nanostructures to control far-field thermal emission. Thermal emitters based on various micro/nanostructures including gratings, photonic crystals, metamaterials and metasurfaces are reviewed and some important applications are summarized. We expect this article can provide a general overview of this field.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.