New insights from broadband simulations into small overmoded smooth and corrugated terahertz waveguides and transitions for NMR-DNP.

The primary impetus for the work reported in this paper is to develop efficient overmoded waveguides (OMWGs) that employ broadband downtaper transitions that would be compatible with the severe space constraints in high-field NB magnets. Further, it is essential these would be readily manufacturable, as high precision corrugated metallic downtapers for the sub-mmw regime are very difficult to produce. We have simulated numerous alternatives to corrugated circular OMWGs, including most of the previously reported alternatives (except for many of the low-power fiberoptics options) and several novel designs.

Molecular dynamics discovery of an extraordinary ionic migration mechanism in dislocation-containing TlBr crystals.

TlBr can surpass CZT as the leading semiconductor for γ- and X-radiation detection. Unfortunately, the optimum properties of TlBr quickly decay when an operating electrical field is applied. Quantum mechanical studies indicated that if this property degradation comes from the conventional mechanism of ionic migration of vacancies, then an unrealistically high vacancy concentration is required to account for the rapid aging of TlBr seen in experiments.

Get the light out: nanoscaling MOFs for luminescence sensing and optical applications.

Optical transparency is a critical but often overlooked property of MOFs considered for optical applications and luminescence sensing. Zr-1,4-NDC samples with various crystallite dimensions (35 nm to 100 μm) were prepared and their bulk optical transmittance measured. The nanocrystalline (35 nm) sample exhibited the highest optical transmittance, which boosts the luminescence signal for sensing applications by reducing scattering loss.

Hybrid Polymer/Metal-Organic Framework Films for Colorimetric Water Sensing over a Wide Concentration Range.

Because of their extraordinary surface areas and tailorable porosity, metal-organic frameworks (MOFs) have the potential to be excellent sensors of gas-phase analytes. MOFs with open metal sites are particularly attractive for detecting Lewis basic atmospheric analytes, such as water. Here, we demonstrate that thin films of the MOF HKUST-1 can be used to quantitatively determine the relative humidity (RH) of air using a colorimetric approach.