Theoretical Understanding on the Chemical Principles of Atomic Layer Deposition Bonggeun Shong Chemical Engineering, Hongik University Atomic layer deposition (ALD) is a vapor phase thin film deposition technique based on sequential, self-limiting surface reactions. Through ALD, exceptional conformality on high-aspect ratio structures, thickness control at the Angstrom level,...
Abstract Living matter, from plants and animal cells, comprises complex materials with various phases and interfaces. A close look at how these soft interfaces arise and form certain shapes with functions will not only deepen our understanding of nature but also inspire the design and engineering of materials for novel applications. In this talk, I will first introduce hydrodynamic synchronization, which can be observed in swimming organisms, and explain how hydrodynamically interacting fluid-fluid interfaces can act as coupled oscillators leading to the discovery of a synchronized droplet generation. Second, I will present methods to fabricate nature-inspired shapes of microstructure to provide multifunctionality to the material, such as wrinkles on curved surfaces and multi-compartment microfibers, by exploiting oil-water interfaces. Lastly, I will investigate biological cells as soft matter to study the dependence of their motility on the geometry of cells and confinements as in complex tissue environments. We can even use materials found in our kitchen to understand the physicochemical roles of complex fluids in determining the shapes and motility of nature. My ultimate research goal in soft interfaces is to apply the knowledge from complex fluids experiments to emerging technologies of biomedical applications....
Realizing a clinical-grade electronic medicine for peripheral nerve disorders is challenging owing to the lack of rational material design that mimics the dynamic mechanical nature of peripheral nerves. Specifically, long-term stability of devices interfacing peripheral nerves is challenging, since dynamic mechanical deformations in peripheral nerves...
Novel Approaches for Emerging Rechargeable Batteries Jang Wook Choi (최장욱) School of Chemical and Biological Engineering, Seoul National University, Republic of Korea *e-mail address (jangwookchoi@snu.ac.kr) Although Li-ion batteries have been successful in various applications, their shortcomings with regard to high cost and global maldistribution of raw materials, as well as safety concerns have promoted alternative rechargeable batteries based on other carrier ions represented by sodium and magnesium ions, targeting grid-scale energy storage systems (ESSs). However, many electrode materials in these emerging systems often suffer from sluggish kinetics due to the larger size or bivalency of carrier ions, limiting electrochemical performance particular in specific capacity and operation voltage. In this talk, I will introduce a new approach of engaging intercalated water in layered cathode materials. The intercalated water improves the performance of the given materials substantially by shielding electrostatic interactions or maintaining the crystal frameworks over repeated cycles. Detailed effects of intercalated water will also be described, along with promising potentials towards aqueous operations. I will also briefly introduce recent studies on zinc metal electrodes in light of managing surface side reactions including hydrogen evolution reaction (HER). ...
Recent advancements in the synthesis of carbon nanotubes Jaegeun Lee School of Chemical Engineering, Pusan National University, Busan, Republic of Korea, 46241 jglee@pusan.ac.kr Carbon nanotubes (CNTs) are one of the earliest nanomaterials that opened up the era of nanotechnology about 30 years ago. During the past three decades, the...
High-fidelity Flow Simulation for Turbomachinery Jin Lee (Department of Mechanical Engineering, Dong-A University) Abstract For energy conversion between thermo-fluid and mechanical energy, turbomachinery is widely used, from air purifiers, wind turbines to airplane engines. Airplane engines, in particular gas-turbine engines, are complicated systems combined with multiple turbomachinery components. Here, the performance of turbomachinery is based on fluid mechanics and thermodynamics, and durability is based on thermodynamics and solid mechanics. In order to reduce total development cost amid increasing computing resources and techniques, aero-thermal simulation and analysis are getting critical. Computational fluid dynamics (CFD) in this research field have been used to solve numerous issues related to the multi-disciplinary analysis in gas-turbine engines. Nowadays, more effort has been added to improve the fidelity of the computation by resolving turbulence. Also, machine learning helps the accuracy of the regular-fidelity simulation. Based on the background, this presentation focuses on several examples of CFD researches in the turbomachinery industry. After giving an overview of the CFD research for gas-turbine engines, (i) large-eddy simulation (LES) of compressor cascade and (ii) hybrid RANS/LES simulation for multi-stage turbine will be presented. Finally, the future of the gas turbine engine will be introduced briefly. Bio Jin LEE is an assistant professor at Dong-A University (DAU), Busan, South Korea. He received his Ph.D. degree from KAIST in 2014, and received the outstanding dissertation award in 2015 from the Korean Society of Mechanical Engineers (KSME). Before joining DAU, he investigated the transitional boundary layer at Johns Hopkins University as a postdoctoral fellow (2014-2017). Then, he joined Raytheon Technologies Research Center (formerly, United Technologies Research Center (UTRC)) as a research engineer, and contributed for aerodynamics and acoustics in turbo-fan engines and hypersonic missiles (2017-2021). His research area encompasses the direct numerical simulation (DNS) of complex flows to the RANS/LES simulation of the turbomachinery flow....
