A5011107893- Spectroscopy and Quantum Chemical Studies
- Advanced Thermodynamics and Statistical Mechanics
- Gene Regulatory Network Analysis
- stochastic dynamics and bifurcation
- Material Dynamics and Properties
- Theoretical and Computational Physics
- Advanced Chemical Physics Studies
- Protein Structure and Dynamics
- Semiconductor materials and devices
- Advanced Fluorescence Microscopy Techniques
- Photochemistry and Electron Transfer Studies
- Fractional Differential Equations Solutions
- thermodynamics and calorimetric analyses
- Advancements in Semiconductor Devices and Circuit Design
- Diffusion and Search Dynamics
- Molecular Junctions and Nanostructures
- Spectroscopy and Laser Applications
- Rheology and Fluid Dynamics Studies
- nanoparticles nucleation surface interactions
- Lipid Membrane Structure and Behavior
- Surfactants and Colloidal Systems
- Microtubule and mitosis dynamics
- Stochastic processes and statistical mechanics
- Molecular spectroscopy and chirality
- Advanced Memory and Neural Computing
Chung-Ang University
2014-2025
Chungnam National University
2020-2023
Creative Research
2020
Kyung Hee University Hospital at Gangdong
2015
University of Arkansas for Medical Sciences
2015
Korea University
2000-2015
Pusan National University
2007-2009
Massachusetts Institute of Technology
2001-2008
Seoul National University
1992-2008
University of Oxford
2008
We show that there are two regimes of irreversible, kinetic aggregation aqueous colloids, determined by the short-range interparticle potential, through its control sticking probability upon approach particles. Each regime has different rate-limiting physics, dynamics, and cluster-mass distributions, results in clusters with fractal dimensions. These set limits on dimension, ${d}_{f}$, for gold aggregates $1.75<~{d}_{f}<~2.05$ (\ifmmode\pm\else\textpm\fi{}0.05).
We study the dynamics of diffusion-limited cluster-cluster aggregation aqueous colloids using quasielastic light scattering. Scaling behavior is found for dependence mean cluster size on both time and initial concentration, limits are placed scaling exponents mass distribution. The fractal nature resultant clusters directly affects exponents, illustrating inherent relationship between dynamic static properties kinetic processes.
Chemosignaling of hydrazine by selective deprotection levulinated coumarin was investigated. In the presence hydrazine, selectively deprotected, resulting in chromogenic and fluorescent turn-on type signaling. The naked-eye detectable signaling possible representative metal ions common anions an aqueous environment.
A new neutral 1D channel thorium organic framework material (TOF-2) has been synthesized under hydrothermal conditions. TOF-2 exhibits a hexagonal structure consisting of eight-coordinate ThO6F2 polyhedra and 1,3,5-benzentricarboxylate ligands. The channels run along the c-axis are approximately 13 in diameter. single-crystal X-ray suggests that amount void space is 41%. stable to ca. 400 degrees C. Gas adsorption measurements show deferential gas uptake behavior.
Singlet oxygen is a toxic chemical but powerful oxidant, exploited in many and biological applications. However, the lifetime of singlet air under atmospheric conditions yet to be known. This has limited safe usage air, despite being strong antimicrobial agent with unique property relaxing breathable after serving its purpose. Here, we solve this long-standing problem by combining experimental theoretical research efforts; generate using photosensitizer at local source monitor time-dependent...
Thermal motion in complex fluids is a complicated stochastic process but ubiquitously exhibits initial ballistic, intermediate subdiffusive, and long-time diffusive motion, unless interrupted. Despite its relevance to numerous dynamical processes of interest modern science, unified, quantitative understanding thermal remains challenging problem. Here, we present transport equation solutions, which yield unified explanation the mean-square displacement (MSD), non-Gaussian parameter (NGP),...
Supersaturation, nucleation, and phase separation are ubiquitous phenomena of great interest in both science industry. However, a unified, quantitative understanding these has yet to be achieved for mesoscopic materials. Here, we present set general equations that determine the monomer saturation degree, size distribution free energy materials, as well their transition conditions. These reveal that, under supersaturation, largest cluster (LCS) is an important state-variable; supersaturation...
Metabolism is a complex network of chemical reactions in which transient biomolecules are continuously produced and degraded. Mimicking this dynamic process synthetic systems poses considerable challenge, as it requires designs that enable the exchange energy matter among molecules. In study, we explored chemically driven oligoesterification operating within highly intricate reaction constructed library oligoesters. Our kinetic analysis uncovered an intriguing phenomenon: oligoesters undergo...
Metabolism is a complex network of chemical reactions in which transient biomolecules are continuously produced and degraded. Mimicking this dynamic process synthetic systems poses considerable challenge, as it requires designs that enable the exchange energy matter among molecules. In study, we explored chemically driven oligoesterification operating within highly intricate reaction constructed library oligoesters. Our kinetic analysis uncovered an intriguing phenomenon: oligoesters undergo...
We present a theory of the four-wave-mixing (FWM) spectroscopy for multilevel system coupled to bath with arbitrary time scale, in contrast most previous work that assumes fast dynamic limit (motionally narrowed limit). Exact quantum mechanical expressions relevant nonlinear response tensor and polarization vector are obtained model Hamiltonian. Effects molecular rotation directions input radiation fields also fully taken into account. The results show how cross correlation as well...
Gene expression is a complex stochastic process composed of numerous enzymatic reactions with rates coupled to hidden cell-state variables. Despite advances in single-cell technologies, the lack theory accurately describing gene has restricted robust, quantitative understanding variability among cells. Here we present Chemical Fluctuation Theorem (CFT), providing an accurate relationship between environment-coupled chemical dynamics and variability. Combined general, model transcription...
Abstract Microbial consortia have been considered potential platforms for bioprocessing applications. However, the complexity in process control owing to use of multiple strains necessitates an efficient population strategy. Herein, we report circuit-guided synthetic acclimation as a strategy improve biochemical production by microbial consortium. We designed consortium comprising alginate-utilizing Vibrio sp. dhg and 3-hydroxypropionic acid (3-HP)-producing Escherichia coli direct...
We present a theory for describing nonclassical dynamics of reactions occurring in disordered media based on the fractional diffusion equation. An exact expression is derived Green’s function required to calculate survival probabilities reactants. A novel temperature-dependent kinetic phase transition found: The exponent γ asymptotic power-law decay (∝t−γ) geminate probability increases with temperature T below critical T*, but decreases above T*. explains unified manner observed features...
The cascading polarization contributing to the femtosecond fifth- and seventh-order coherent Raman scattering processes is obtained in terms of third- fifth-order response functions. It found that four contribute signal. In case scattering, there are 34 possible signal, they classified as χ(5)×χ(3)- χ(3)×χ(3)×χ(3)-types depending on involved low-order nonlinear optical processes. Due complicated interference among these fields, it may not be experimentally measure pure signal without...
We introduce an improved and systematic procedure for solving the diffusion-influenced reaction kinetics problem based on a hierarchical set of kinetic equations many-particle distribution functions. As representative example, we apply formalism to reversible association problem. The new method gives approximate analytic solution which is in almost perfect agreement with Brownian dynamics simulation results whole time range. It shown that previous nonequilibrium function theories are...
It is shown that exactly the same results of memory function theory diffusion-influenced reactions, presented by Yang, Lee, and Shin, can be derived from nonequilibrium reduced distribution (RDF) theory. Instead usual dynamic superposition approximation (SA), which has been widely used to truncate hierarchy RDF evolution equations, we introduce another type truncation approximation. The new provides simple analytic solutions are in better agreement with computer simulation known exact than...
Effects of pair correlations between bound and unbound molecules on the relaxation kinetics fast reversible reactions type A+B⇄C are investigated for one-, two-, three-dimensional reaction systems in a unified manner. Starting from many-body Smoluchowski equations reactant molecule distribution functions, which coupled hierarchical manner, we derive set kinetic by using dynamic superposition approximation. While most previous theories applicable only to pseudo-first order case, present...
Thermal motion and interactions of sub–4-nm particles are directly observed by graphene liquid cell electron microscopy.
It is shown that exactly the same results of modified integral encounter theory (MET) diffusion-influenced reactions can be derived from nonequilibrium reduced distribution function (RDF) theory. The method solution RDF much simpler than MET, and shows clearly sophisticated approximation scheme employed in latter effectively equivalent to a simple truncation adopted former. We evaluate relative accuracy various theories by comparing theoretical with an accurate Brownian dynamics simulation...
New quantum dots were fabricated with a core/shell/shell structure consisting of CdTe core/InP shell/ZnS shell which the InP causes red-shift to NIR region and ZnS imparts photo-stability; toxicity tests on mammalian cells imaging mouse highlight their potential applications in biomedical imaging.
We report a robust quadratic relation between the inverse substrate concentration and second moment, <t2>, of catalytic turnover time distribution for enzyme reactions. The results hold irrespective mechanism dynamics reaction suggest novel single molecule experimental analysis that provides information about processes enzyme−substrate complex ergodicity system, which is beyond reach conventional mean time, <t>. It turns out <t2> − 2<t>2 linear in an ergodic homogeneous system given...
Recently, we proposed a new systematic approach to evaluate the many-particle effects on diffusion-influenced reactions. The method gives an improved result over that obtained by using superposition approximation. In present paper, apply treat kinetics of reversible energy-transfer reactions type A*+B⇄A+B*. Until now, most theories were inapplicable when lifetime A* is shorter than B*, and notable exception was integral encounter theory (IET) Burshtein et al. can be applied irrespective...