Terahertz (THz) frequencies of the electromagnetic spectrum have been underutilized when compared to neighboring microwave and infrared frequencies, largely due to the difficulties controlling and detecting these fields. In a step toward gaining control over THz frequencies, my advisor Dr. Yun-Shik Lee’s group experimentally demonstrated optical-pulse THz-control over a plasmonic...
Molybdenum disulfide (MoS2) has potential applications as a low-cost catalyst for the hydrogen evolution reaction (HER). Defects on MoS2, such as edge sites and sulfur vacancies, are known to be the major active sites for HER. Controlling the formation of these defects allows for the enhancement in reactivity of MoS2...
I construct and examine the properties of Lie and Clifford algebras which are used to describe certain types of particles. These algebras are then related to the traditional theory of division algebras. Quaternions are applied to these algebras and their properties are exploited to model physical properties of particles. The...
Polyoxoniobates (PONbs) are attracting great attention in recent years due to its novelty as well as a variety of geometrical presentations in different pH conditions. In this paper we are reporting the reaction of tetramethyl-decaniobate ([(CH3)4N]6[Nb10O28]) with alkaline carbonates to observe the periodic trend of alkaline ions interacting with the...
Tracking the dynamic morphology of active materials during operation of lithium batteries is essential for identifying causes of performance loss. Digital volume correlation (DVC) is applied to high-speed operando synchrotron X-ray computed tomography of a commercial Li/MnO₂ primary battery during discharge. Real-time electrode material displacement is captured in 3D allowing...
Lithium-ion batteries (LIBs) as energy storage devices play an important role in all aspects of our life. The increasing energy demand of the society requires LIBs with higher energy density and better performance. We here develop a new and easy-to-scaleup sol-gel method to coat a surface protection layer on commercial...
This work explores the electric field induced strain mechanisms in environmentally benign Bi0.5Na0.5TiO3 (BNT) based piezoelectric thin films. Although BNT-based materials show promise as replacements for toxic Pb-based piezoelectrics, the displacement mechanisms are not consistent between thin films and bulk materials, and the differences have yet to be well understood....
Soil moisture strongly affects the balance between nitrification, denitrification and N2O reduction and therefore the nitrogen (N) efficiency and N losses in agricultural systems. In rice systems, there is a need to improve alternative water management practices, which are designed to save water and reduce methane emissions but may increase...
Biomass gasification is a promising way to obtain green energy, but the gas composition makes it unsuitable for use in traditional technologies (i.e., IC engine). Gas purification over nickel and/or iron catalysts is an attractive alternative. Cellulose-based carbon aerogels (CAGs) have shown suitable physical chemical properties for use as catalyst...
Civil engineers frequently use lime to improve the mechanical properties of weak clayey soils. The production of lime is associated with significant CO₂ emissions. Sequestering carbon dioxide into the stabilized soil can effectively reduce the carbon footprint of the lime. In the presence of CO₂, unreacted lime in the stabilized...