Supercattering Channels of Nonspherical structurers

A superscattering structure is an efficient energy-mapping device that of particular importance for various electromagnetic experiment methods, with potential sensing and energy harvesting applications. We study in this work the scattering cross-section of outgoing channels in the irreducible and singular basis for an arbitrary shape scatterer. The superscattering status is shown to occur within a single outgoing channel of an optimized cluster of cylinders, a forbidden mechanism in spherically symmetric Mie resonators.

Heat Mapping, a Method for Enhancing the Sustainability of the Smart District Heat Networks

District heating (DH) has a major potential to increase the efficiency, security, and sustainability of energy management at the community scale. However, there is a huge challenge for decision makers due to the lack of knowledge about thermal energy demand during a year. Thermal energy demand is strongly dependent on the outdoor temperature, building area, and activities. In this context, this paper presents an innovative monthly thermal energy mapping method to calculate and visualize heat demand accurately for various types of buildings. The method includes three consecutive phases: (i) calculating energy loss, (ii) completing a dataset that includes energy and building information, and (iii) generating the monthly heat demand maps for the community. Determining the amount of demand and the best location for energy generators from the perspective of energy efficiency in a DH system in an urban context is one of the important applications of heat maps. Exploring heat demand characteristics and visualizing them on maps is the foundation of smart DHs.

A dose based metric to assess the accuracy of image registration

The relationship between dose mapped using two mapping methods (energy mapping method and voxel warping method) and registration error was examined. The correlation between the difference in doses mapped using these methods, defined as dose mapping difference (DMD), and landmark distance to agreement for a realistic lung patient plan using registrations of varying accuracy was examined. Results showed no correlation between DMD and landmark error. Further investigation on simple dose mapping geometries revealed a correlation of DMD with fractional volume (FVC) change induced by registration errors. A formula for DMD as a function of FVC was derived. Results of this formula agreed with simulated values of DMD with percentage differences less than 3.5% in regions of uniform dose. However, no agreement was found in regions containing a dose gradient. Further work is required in order to extend this formula to regions of dose gradients and scenarios that emulate realistic deformations.

Development of a novel microfluidic device to study metal geochemistry in situ using X-ray fluorescence microprobe spectroscopy

The study of in situ microscale biogeochemical processes represents a major challenge in the environmental sciences. The combination of microfluidic devices with X-ray fluorescence microprobe spectroscopy may address this need, but typical materials used in these devices attenuate the X-rays needed to analyze key elements of interest, such as Fe or As. In this work, a method is presented for fabricating an etched silicon microfluidic device that is sealed with a 30 µm thin glass window that is sufficiently transparent for X-ray fluorescence microprobe spectroscopy. The capabilities of these devices for X-ray microprobe spectroscopy are demonstrated using an Fe (hydr)oxide solid that is loaded with As and then infused with sulfide, on beamline 4-BM at NSLS-II, resulting in time-variant Fe precipitation reactions and As sorption. Key results include in situ X-ray fluorescence time-series maps of Fe, As and a Br flow tracer, as well as spot XANES at both the Fe K edge and As K edge. Additionally, multiple energy mapping is used to examine the spatial speciation of As over time. The results of this work clearly demonstrate the capabilities of this novel microfluidic system that can be analyzed using X-ray fluorescence microprobe spectroscopy and can be made to study a wide range of complex microscale geochemical systems.