A5085983523- Electric Power System Optimization
- Smart Grid Energy Management
- Energy and Environment Impacts
- Thermal properties of materials
- Integrated Energy Systems Optimization
- Advanced X-ray Imaging Techniques
- Power System Reliability and Maintenance
- Thermal Radiation and Cooling Technologies
- Sports Dynamics and Biomechanics
- Heat Transfer and Optimization
- Advanced Electron Microscopy Techniques and Applications
- Diamond and Carbon-based Materials Research
- Advanced Fluorescence Microscopy Techniques
- Water-Energy-Food Nexus Studies
- Near-Field Optical Microscopy
- Composite Material Mechanics
- Adaptive optics and wavefront sensing
- Optimal Power Flow Distribution
- HVDC Systems and Fault Protection
- Metal and Thin Film Mechanics
- Laser-Plasma Interactions and Diagnostics
- Optical Coatings and Gratings
- Nanowire Synthesis and Applications
- Gas Dynamics and Kinetic Theory
- Advancements in Photolithography Techniques
Joint Institute for Laboratory Astrophysics
2021-2024
University of Colorado System
2020-2024
University of Colorado Boulder
2020-2023
National Renewable Energy Laboratory
2017-2019
University of North Carolina at Chapel Hill
2016
The evolving nature of electricity production, transmission, and consumption necessitates an update to the IEEE's Reliability Test System (RTS), which was last modernized in 1996. presented here introduces a generation mix more representative modern power systems, with removal several nuclear oil-generating units addition natural gas, wind, solar photovoltaics, concentrating power, energy storage. includes assigning test system geographic location southwestern United States enable...
Next-generation nano and quantum devices have increasingly complex 3D structure. As the dimensions of these shrink to nanoscale, their performance is often governed by interface quality or precise chemical dopant composition. Here we present first phase-sensitive extreme ultraviolet imaging reflectometer. It combines excellent phase stability coherent high-harmonic sources, unique chemical- phase-sensitivity reflectometry, state-of-the-art ptychography algorithms. This tabletop microscope...
Nanostructuring on length scales corresponding to phonon mean free paths provides control over heat flow in semiconductors and makes it possible engineer their thermal properties. However, the influence of boundaries limits validity bulk models, while first-principles calculations are too computationally expensive model real devices. Here we use extreme ultraviolet beams study transport dynamics a 3D nanostructured silicon metalattice with deep nanoscale feature size observe dramatically...
We demonstrate temporally multiplexed multibeam ptychography implemented for the first time in EUV, by using a high harmonic based light source. This allows simultaneous imaging of different sample areas, or same area at times incidence angles. Furthermore, we show that this technique is compatible with wavelength multiplexing spectroscopic imaging, taking full advantage temporal and spectral characteristics sources. enables increased data throughput simple experimental implementation photon...
Significance A critical factor in determining the achievable speeds and efficiencies of electronic devices is operating temperature. As modern transistors shrink size to as small 5 nm, optimal design for temperature control requires a predictive understanding nanoscale heat dissipation. In this work, we establish fundamental microscopic description thermal transport induced by sources. We uncover underlying mechanism that drives counterintuitive behavior discovered recently via extreme UV...
We present an investigation of a partially elastic ball bouncing on vertically vibrated concave parabolic surface in two dimensions. In particular, we demonstrate that simple vertical motion, wherein the bounces periodically at parabola's vertex, is unstable to horizontal perturbations when coefficient defining shape exceeds critical value. The result new periodic solution where laterally over vertex. As parabola further steepened, this also becomes which gives rise other complex and chaotic...
While contiguous power systems are often operated by several regional system operators, optimization models have traditionally been designed to generate optimal system-wide scheduling decisions. This paper presents an approach reflect the existence of multiple operators making decisions within interconnected system. is explicitly each operator's limited knowledge about other regions when Detailed analysis using a modified IEEE Reliability Test System reveals that mimics real operations...
Integration of large scale renewables into the electrical grid is currently one major challenges and priorities for many countries. The Government India (GOI) has committed to install 175 GW renewable energy (RE) by 2022. Due favorable policies, RE capacity in recently exceeded 60 GW, overtaking hydropower as second largest fleet. To assess impact on power system, three studies (one national two regional) were undertaken jointly United States Agency International Development (USAID) Ministry...
Understanding nanoscale electron and phonon transport is critical for the development of next-generation semiconductor technologies, where deviations from macroscopic behaviors can either limit or enhance device performance. While transient gratings generated by interference visible lasers directly excite microscopic, nonequilibrium charge heat distributions in metals traditional semiconductors, extending this noncontact approach to ultrawide-bandgap materials involves added complexities. To...
We use ultrafast, extreme ultraviolet high harmonic beams to fully characterize a silicon metalattice, novel nanostructured semiconductor material. then develop general, predictive model for the highly-confined heat flow behavior in materials.
Semiconductor metalattices consisting of a linked network three-dimensional nanostructures with periodicities on length scale <100 nm can enable tailored functional properties due to their complex nanostructuring. For example, by controlling both the porosity and pore size, thermal transport in these phononic be tuned, making them promising candidates for efficient thermoelectrics or rectifiers. Thus, ability characterize porosity, other physical properties, is critical but challenging,...
Nanostructured semiconductors can exhibit thermal properties unachievable in bulk systems and will play a crucial role next-generation nanoelectronics energy efficient devices, where heat evacuation poses critical limitation. However, first principles models are too computationally challenging for 3D nanostructured geometries, while ballistic phonon descriptions make overly-simplistic assumptions about the nature of phonon-boundary interactions. Here, we study flow silicon metalattice...
We present a tabletop EUV imaging reflectometer that can characterize the geometry and composition of nanostructures. The setup be operated in multiple modes — intensity reflectometry, scatter-reflectometry, or reflectometry depending on length scales periodicity nanostructures present. All these metrology performed non-destructively lab-scale setup, using high-harmonic coherent source.