시뮬레이션을 통한 SiC MOSFET의 단락회로 보호방법 연구

김현구(Hyunku Kim),김솔준(Soljun Kim),신용민(Yongmin Shin) 한국자동차공학회 2023 한국자동차공학회 부문종합 학술대회 Vol.2023 No.5

Recently, SiC MOSFETs are increasingly being used instead of IGBT for electrified vehicles. SiC MOSFET has many advantages such as high breakdown electric field, low ON resistance, and fast switching speed due to good temperature characteristics. However, there are points to consider when using the device, such as small semiconductor die size, high current density and rapid breakdown under short-circuit conditions. In particular, studies are being conducted to prevent the SiC MOSFET from breakdown due to overcurrent occurring during a short circuit. At the end of the day, no document has been clearly presented, and the methods used in the existing IGBT continue to be used. In this paper, using the desaturation detection method, which is one of the existing methods for IGBT, a method to set an appropriate blanking time was studied through simulation, and it was confirmed that the results were valid.

In-Plate and On-Plate Structural Control of Ultra-Stable Gold/Silver Bimetallic Nanoplates as Redox Catalysts, Nanobuilding Blocks, and Single-Nanoparticle Surface-Enhanced Raman Scattering Probes

Oh, Ju-Hwan,Shin, Hyunku,Choi, Jong Yun,Jung, Hee Won,Choi, Yeonho,Lee, Jae-Seung American Chemical Society 2016 ACS APPLIED MATERIALS & INTERFACES Vol.8 No.40

<P>Noble metal bimetallic nanomaterials have attracted a great deal of attention owing to the strong correlation between their morphology and chemical and physical properties. Even though the synthetic strategies for controlling the shapes of monometallic nanomaterials such as gold (Au) and silver (Ag) are well-developed, limited advances have been made with Au/Ag bimetallic nanomaterials to date. In this work, we demonstrate a highly complex in-plate and on-plate structural control of Au/Ag bimetallic nanoplates (Au/AgBNPLs) in contrast to conventional, simply structured, 1D and 2D, branched, and polyhedral nanomaterials. The polymer used in the synthesis of seeds plays a critical role in controlling the structure of the Au/AgBNPLs. The Au/AgBNPLs exhibit exceptionally high chemical stability against various chemical etchants and a versatile catalytic reactivity with biologically and environmentally relevant chemical species. Significantly, the reversible assembly formation of the Au/AgBNPLs is demonstrated by carrying out the surface-functionalization of the materials with thiol DNA, emphasizing the potential applications of the Au/AgBNPLs in various diagnostic and therapeutic purposes. Finally, the surface-enhanced Raman scattering (SERS) properties of the Au/AgBNPLs are experimentally and theoretically investigated, demonstrating a substantial potential of the Au/AgBNPLs as single-nanoparticle SERS probes. Electron microscopy, UV vis spectroscopy, selected area electron diffraction (SAED), and energy dispersive X-ray (EDX) spectroscopy are employed to analyze the structure and composition of the Au/AgBNPLs at the atomic level.</P>

Identification of Newly Emerging Influenza Viruses by Detecting the Virally Infected Cells Based on Surface Enhanced Raman Spectroscopy and Principal Component Analysis

Lim, Jae-young,Nam, Jung-soo,Shin, Hyunku,Park, Jaena,Song, Hye-in,Kang, Minsung,Lim, Kwang-il,Choi, Yeonho American Chemical Society 2019 ANALYTICAL CHEMISTRY - Vol.91 No.9

<P>Rapid diagnosis and quarantine of influenza virus mutant-infected people is critical to contain the fatal viral infection spread because effective antiviral drugs are normally not available. Conventional methods, however, cannot be used for the diagnosis because these methods need predefined labels, likely also unavailable for just emerging viruses. Here, we propose label-free identification of cells infected with different influenza viruses based on surface-enhanced Raman spectroscopy (SERS) and principal component analysis (PCA). Viral envelope proteins that are displayed on the surface of cells after infection of influenza viruses were targeted for this identification. Cells that expressed the envelope proteins of A/WSN/33 H1N1 or A/California/04/2009 H1N1 influenza viruses produced distinct SERS signals. Cells that displayed combinations of the envelope proteins from these two viral variants, an indication of emergence of a new virus, also generated characteristic SERS patterns. However, the cell’s own surface proteins often hindered the identification of virally infected cells by producing SERS peaks similar to viral ones. PCA of the obtained SERS patterns could effectively capture the virus-specific signal components from the jumbled SERS peaks. Our study demonstrates a potential of combination of SERS and PCA to identify newly emerging influenza viruses through sensing the cells infected with the viruses.</P> [FIG OMISSION]</BR>

Flexible and Stable Omniphobic Surfaces Based on Biomimetic Repulsive Air-Spring Structures

Seo, Dongkwon,Cha, Suk-kyong,Kim, Gijung,Shin, Hyunku,Hong, Soonwoo,Cho, Yang Hyun,Chun, Honggu,Choi, Yeonho American Chemical Society 2019 ACS APPLIED MATERIALS & INTERFACES Vol.11 No.6

<P>In artificial biological circulation systems such as extracorporeal membrane oxygenation, surface wettability is a critical factor in blood clotting problems. Therefore, to prevent blood from clotting, omniphobic surfaces are required to repel both hydrophilic and oleophilic liquids and reduce surface friction. However, most omniphobic surfaces have been fabricated by combining chemical reagent coating and physical structures and/or using rigid materials such as silicon and metal. It is almost impossible for chemicals to be used in the omniphobic surface for biomedical devices due to durability and toxicity. Moreover, a flexible and stable omniphobic surface is difficult to be fabricated by using conventional rigid materials. This study demonstrates a flexible and stable omniphobic surface by mimicking the re-entrant structure of springtail’s skin. Our surface consists of a thin nanohole membrane on supporting microstructures. This structure traps air under the membrane, which can repel the liquid on the surface like a spring and increase the contact angle regardless of liquid type. By theoretical wetting model and simulation, we confirm that the omniphobic property is derived from air trapped in the structure. Also, our surface well maintains the omniphobicity under a highly pressurized condition. As a proof of our concept and one of the real-life applications, blood experiments are performed with our flat and curved surfaces and the results including contact angle, advancing/receding angles, and residuals show significant omniphobicity. We hope that our omniphobic surface has a significant impact on blood-contacting biomedical applications.</P> [FIG OMISSION]</BR>

Rapid identification of newly emerging influenza viruses by surface-enhanced Raman spectroscopy

Se-eun YANG,Jung-soo NAM,Jae-young LIM,Hyunku SHIN,Yoon-ha JANG,Gyu-Un BAE,Taewook KANG,Kwang-il LIM,Yeonho CHOI 한국생물공학회 2015 한국생물공학회 학술대회 Vol.2015 No.10

Identification of Newly Emerging Influenza Viruses by Surface-Enhanced Raman Spectroscopy

Lim, Jae-young,Nam, Jung-soo,Yang, Se-eun,Shin, Hyunku,Jang, Yoon-ha,Bae, Gyu-Un,Kang, Taewook,Lim, Kwang-il,Choi, Yeonho American Chemical Society 2015 ANALYTICAL CHEMISTRY - Vol.87 No.23

<P>In this work, we demonstrate <I>in situ</I> virus identification based on surface-enhanced Raman scattering (SERS). We hypothesized that newly emerging influenza viruses possess surface proteins and lipids that can generate distinctive Raman signals. To test this hypothesis, SERS signals were measured from the surface of a noninfluenza virus, two different influenza viruses, and a genetically shuffled influenza virus. To ensure the safety for experimenters we constructed nonreplicating pseudotyped viruses that display main influenza virus surface components. Pseudotype with influenza virus components produced enhanced Raman peaks, on gold nanoparticles, that are easily distinguishable from those of pseudotype with a noninfluenza virus component, vesicular stomatitis virus G protein (VSVG). Furthermore, virus with the surface components of a newly emerging influenza strain, A/California/04/2009 (H1N1), generated Raman peaks different from those of viruses with components of the conventional laboratory-adapted influenza strain, A/WSN/33 (H1N1). Interestingly, the virus simultaneously displaying surface components of both influenza strains, a model mutant with genome reassortment, also produced a Raman signal pattern that is clearly distinguishable from those of each strain. This work highlights that SERS can provide a powerful label-free strategy to quickly identify newly emerging and potentially fatal influenza viruses.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/ancham/2015/ancham.2015.87.issue-23/acs.analchem.5b02661/production/images/medium/ac-2015-02661m_0008.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ac5b02661'>ACS Electronic Supporting Info</A></P>