Determining Ergonomic Smartphone Forms With High Grip Comfort and Attractive Design

Lee, Songil,Kyung, Gyouhyung,Yi, Jihhyeon,Choi, Donghee,Park, Sungryul,Choi, Byeonghwa,Lee, Seungbae SAGE Publications 2019 Human factors Vol.61 No.1

Selective SnO_<i>x</i> Atomic Layer Deposition Driven by Oxygen Reactants

Lee, Jung-Hoon,Yoo, Mi,Kang, DongHee,Lee, Hyun-Mo,Choi, Wan-ho,Park, Jung Woo,Yi, Yeonjin,Kim, Hyun You,Park, Jin-Seong American Chemical Society 2018 ACS APPLIED MATERIALS & INTERFACES Vol.10 No.39

<P>SnO<SUB><I>x</I></SUB> thin films were successfully deposited by the thermal atomic layer deposition (ALD) method using <I>N</I>,<I>N</I>′-<I>tert</I>-butyl-1,1-dimethylethylenediamine stannylene(II) as a precursor and ozone and water as reactants. The growth of SnO and SnO<SUB>2</SUB> films could be easily controlled by employing different reactants and utilizing different ozone and water concentrations, respectively. The formation of both SnO and SnO<SUB>2</SUB> films exhibited typical surface-limiting reaction characteristics, although their growth behaviors differ from one another. The combined studies of density functional theory calculations and experimental analyses showed that the difference in growth behavior of the SnO and SnO<SUB>2</SUB> films can be attributed to the stability of ozone and water on the SnO<SUB>2</SUB> and SnO films. SnO and SnO<SUB>2</SUB> films have different crystal structures and both films were crystallized from the amorphous to polycrystalline states following an increase in the deposition temperature. The absorbance and refractive index of the thin films were investigated using ultraviolet-visible spectroscopy (UV-vis) and spectroscopic ellipsometry (SE), respectively. SnO<SUB><I>x</I></SUB> films formed using ozone and water as a reactant showed an optical band gap of 3.60-3.17 eV and 2.24-2.30 eV and refractive indices of ∼2.0 and ∼2.6, respectively, which correspond to values typical of SnO<SUB>2</SUB> and SnO. The bilayer structure of SnO/SnO<SUB>2</SUB> was successfully fabricated on indium tin oxide (ITO) glass with nickel as a top electrode at 100 °C. The SnO/SnO<SUB>2</SUB> bilayer exhibited diode characteristics with a current rectification ratio of 15. Our results present a simple but highly versatile growth method for producing multilayer oxide films with electronic properties that can be finely controlled.</P> [FIG OMISSION]</BR>

Comparative Analysis of Burnup Uncertainty for Spent Fuel

Donghee Lee,Yongdeog Kim,Kiyoung Kim 한국방사성폐기물학회 2023 한국방사성폐기물학회 학술논문요약집 Vol.21 No.1

After spent fuel is stored in a dry storage container, it becomes difficult to obtain information on the fuel’s characteristics. As a result, it is necessary to identify the characteristics of spent nuclear fuel in advance and secure the information necessary to establish delivery acceptance requirements for interim storage and disposal in the future. Therefore, it is necessary to evaluate the characteristics of spent fuel before loading dry storage casks. In order to prepare for the dry storage of spent fuel, information on the basic characteristics of the fuel is required. As part of this information, it is also necessary to establish calculation criteria for spent fuel burnup. Spent fuel burnup can be classified into three categories. The first is burnup evaluated using design codes (design burnup), the second is burnup measured by furnace instruments during power plant operation (actual burnup), and the third is burnup measured through measurement equipment (measured burnup). This paper describes a comparative evaluation of design burnup, actual burnup, and measured burnup for specific fuels (40 bundles).

Management and Disposal Plans for Spent Fuel/HLW in Various Countries Around the World

Donghee Lee,Taehyeon Kim,TaeHyung Na 한국방사성폐기물학회 2023 한국방사성폐기물학회 학술논문요약집 Vol.21 No.1

As of 2023, there has been significant progress worldwide in the management of nuclear fuel’s spent radioactive waste (HLW). Several countries have made important strides in advancing their plans for the construction of deep geologic repositories (DGRs) to safely dispose of their nuclear waste. Finland led the way, with its nuclear waste management organization, Posiva Oy, submitting an application for an operating license for a DGR for spent fuel generated by the nuclear power plants of its owners. The facility, ONKALO, will be located on the island of Olkiluoto and is expected to begin final disposal in the mid-2020s. Sweden also approved SKB’s application to build a DGR in Forsmark, and an encapsulation plant next to the Clab interim storage facility. In Switzerland, Nagra selected Nordic Lagern as the site for the Swiss DGR, and is preparing the general license applications for the required facilities. Meanwhile, Canada’s Nuclear Waste Management Organization (NWMO) narrowed down the possible locations for its DGR to two, and expects to name its preferred site by fall 2024. The UK established four Community Partnerships to participate in the siting process for a DGR, with Nuclear Waste Services (NWS) responsible for identifying a site. Andra, the French organization responsible for managing all French radioactive waste, is expected to submit an application by the end of the year for a DGR in France that will contain HLW resulting from reprocessing of spent fuel assemblies from French nuclear power plants, as well as intermediate-level waste. Overall, the progress made by these countries represents a tangible and sustainable step forward in the management of spent fuel and HLW, and brings us closer to the safe and effective long-term disposal of nuclear waste.

On-Chip Parylene-C Microstencil for Simple-to-Use Patterning of Proteins and Cells on Polydimethylsiloxane

Lee, Donghee,Yang, Sung American Chemical Society 2013 ACS APPLIED MATERIALS & INTERFACES Vol.5 No.7

<P>Polydimethylsiloxane (PDMS) is widely used as a substrate in miniaturized devices, given its suitability for execution of biological and chemical assays. Here, we present a patterning approach for PDMS, which uses an on-chip Parylene-C microstencil to pattern proteins and cells. To implement the on-chip Parylene-C microstencil, we applied SiO<I>x</I>-like nanoparticle layers using atmospheric-pressure plasma-enhanced chemical vapor deposition (AP-PECVD) of tetraethyl orthosilicate (TEOS) mixed with oxygen. The complete removal of Parylene-C from PDMS following application of SiO<I>x</I>-like nanoparticle layers was demonstrated by various surface characterization analysis, including optical transparency, surface morphology, chemical composition, and peel-off force. Furthermore, the effects of the number of AP-PECVD treatments were investigated. Our approach overcomes the tendency of Parylene-C to peel off incompletely from PDMS, which has limited its use with PDMS to date. The on-chip Parylene-C microstencil approach that is based on this Parylene-C peel-off process on PDMS can pattern proteins with 2-μm resolution and cells at single-cell resolution with a vacancy ratio as small as 10%. This provides superior user-friendliness and a greater degree of geometrical freedom than previously described approaches that require meticulous care in handling of stencil. Thus, this patterning method could be applied in various research fields to pattern proteins or cells on the flexible PDMS substrate.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/aamick/2013/aamick.2013.5.issue-7/am4001166/production/images/medium/am-2013-001166_0012.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/am4001166'>ACS Electronic Supporting Info</A></P>

Comparative Assessment of Radiation Shielding in Low Water Level Spent Fuel Pools

Donghee Lee,Yongdeog Kim,Kiyoung Kim 한국방사성폐기물학회 2023 한국방사성폐기물학회 학술논문요약집 Vol.21 No.2

After the Fukushima disaster, overseas nuclear power plants have established conditions for issuing a red alert in the event of fuel damage within the spent fuel pool and they have already implemented conditions for issuing a blue alert when fuel is exposed above the water surface. In South Korean nuclear power plants, a real-time monitoring system is in place to oversee the exposure of spent fuel to the surface within the spent fuel pool. To achieve this, a water level indicator gauge is installed within the spent fuel pool, allowing for continuous real-time monitoring. This paper conducted a comparative assessment of radiation levels from water level monitoring system in two units’ spent fuel pools based on the low water levels (1 feet from the storage rack), utilizing the radiation analysis code (MCNP).

Recommending valuable ideas in an open innovation community : A text mining approach to information overload problem

Lee, Hanjun,Choi, Keunho,Yoo, Donghee,Suh, Yongmoo,Lee, Soowon,He, Guijia Emerald Group Publishing Limited 2018 Industrial Management & Data Systems Vol.118 No.4

Improvement Characteristics of Bio-active Materials Coated Fabric on Rat Muscular Mitochondria

Lee, Donghee,Kim, Young-Won,Kim, Jung-Ha,Yang, Misuk,Bae, Hyemi,Lim, Inja,Bang, Hyoweon,Go, Kyung-Chan,Yang, Gwang-Wung,Rho, Yong-Hwan,Park, Hyo-Suk,Park, Eun-Ho,Ko, Jae-Hong The Korean Society of Pharmacology 2015 The Korean Journal of Physiology & Pharmacology Vol.19 No.3

This study surveys the improvement characteristics in old-aged muscular mitochondria by bio-active materials coated fabric (BMCF). To observe the effects, the fabric (10 and 30%) was worn to old-aged rat then the oxygen consumption efficiency and copy numbers of mitochondria, and mRNA expression of apoptosis- and mitophagy-related genes were verified. By wearing the BMCF, the oxidative respiration significantly increased when using the 30% materials coated fabric. The mitochondrial DNA copy number significantly decreased and subsequently recovered in a dose-dependent manner. The respiratory control ratio to mitochondrial DNA copy number showed a dose-dependent increment. As times passed, Bax, caspase 9, PGC-$1{\alpha}$ and ${\beta}$-actin increased, and Bcl-2 decreased in a dose-dependent manner. However, the BMCF can be seen to have had no effect on Fas receptor. PINK1 expression did not change considerably and was inclined to decrease in control group, but the expression was down-regulated then subsequently increased with the use of the BMCF in a dose-dependent manner. Caspase 3 increased and subsequently decreased in a dose-dependent manner. These results suggest that the BMCF invigorates mitophagy and improves mitochondrial oxidative respiration in skeletal muscle, and in early stage of apoptosis induced by the BMCF is not related to extrinsic death-receptor mediated but mitochondria-mediated signaling pathway.

Intentional Aircraft Crashes on the On-Site SNF Dry Storage Facilities

Donghee Lee,Taehyung Na,Sunghwan Chung 한국방사성폐기물학회 2023 한국방사성폐기물학회 학술논문요약집 Vol.21 No.2

Since the September 11 terrorist attacks in the United States, concerns about intentional aircraft crashes into nationally critical facilities have soared in countries around the world. The United States government advised nuclear utilities to strengthen the security of nuclear power plants against aircraft crashes and stipulated aircraft crash assessment for new nuclear facilities. Interest in military missile attacks on nuclear facilities has grown after Russia attacked Ukraine’s Zaporizhzhia nuclear power plant, where spent nuclear power dry storage facility is operated. Spent nuclear fuel dry storage facilities in nuclear power plant sites should also strengthen security in preparation for such aircraft crashes. Most, but not all, spent nuclear fuel dry storage facilities in Europe, Japan and Canada are operated within buildings, while the United States and Korea operate dry storage facilities outdoors. Since all of Korea’s dry storage systems are concrete structures vulnerable to crash loads and are exposed to the outside, it is more necessary to prepare for aircraft crash terrorist attacks due to the Korea’s military situation. Residents near nuclear power plants are also demanding assessment and protective measures against such aircraft crashes. However, nuclear power plants, including spent nuclear fuel dry storage facilities, are strong structures and have very high security, so they are unlikely to be selected as targets of terrorism, and spent nuclear fuel dry storage systems are so small that aircraft cannot hit them accurately. Collected opinions on the assessment of aircraft crash accidents at spent nuclear fuel dry storage facilities in nuclear power plant sites were reviewed. In addition, the current laws and regulatory requirements related to strengthening the security of new and existing nuclear power plants against intentional aircraft crashes are summarized. Such strengthening of security can not only ensure the safety of on-site spent nuclear fuel dry storage facilities, but also contribute to the continuous operation of nuclear power plants by increasing resident acceptance.

Long-term clinical course and outcome of Korean patients with microscopic polyangiitis associated interstitial lung disease

( Donghee Lee ),( Jinwoo Song ),( Jooae Choe ),( Heesang Hwang ) 대한결핵 및 호흡기학회 2019 대한결핵 및 호흡기학회 추계학술대회 초록집 Vol.127 No.-

Background: Microscopic polyangiitis (MPA) is a systemic vasculitis affecting small vessels. Interstitial lung disease (ILD) is the most common pulmonary manifestations of MPA and is known to be associated with poor outcome. This study aimed to investigate clinical course and outcome in Korean patients with MPA -ILD and to find out prognostic factors. Methods: Clinical data were retrospectively analyzed in 37 patients with MPA-ILD (biopsy proven case, n=5) between 2000 to 2019 at Asan Medical Center. High resolution computed tomography (HRCT) images were categorized as usual interstitial pneumonia (UIP) pattern and others. Results: The median follow-up period was 51.2 months. Of total patients, the mean age was 68.8 years, 62% was male, and 64% was ever-smokers. Six (16.2%) patients died during followup, and the median survival period was 51.5 months (survival rate, 1 year: 86.5%, 3 year: 64.9%, 5 year 46%). Nonsurvivors, at baseline, showed lesser frequent renal involvement and a tendency to have older age, and lesser frequent MPO-positivity, than survivors. However, there were no differences in gender, respiratory symptoms, lung functions, exercise capacity and bronchoalveolar lavage fluid findings between nonsurvivors and survivors. During follow-up, there were more frequent acute exacerbation, pneumonia and alveolar hemorrhage in nonsurvivors compared with survivors. In multivariate Cox analysis, old age was an independent prognostic factor (hazard ratio: 1.209, 95% confidence interval: 1.003-1.457, p=0.046 ) in patients with MPA-ILD. Conclusions: In this study, clinical course and outcome of Korean patients with MPA-ILD were similar to previous reports. Old age means poor prognosis in patients with MAP-ILD.