Interplay among ozone and nitrogen oxides in air plasmas: Rapid change in plasma chemistry

Park, Sanghoo,Choe, Wonho,Jo, Cheorun Elsevier 2018 Chemical Engineering Journal Vol.352 No.-

<P><B>Abstract</B></P> <P>Air is obligatorily used as a supply gas in most of the plasma-aided processing (<I>e.g.</I>, plasma-catalysis) systems because it is the most cost-effective approach, but the simultaneous production of gaseous ozone and nitrogen oxides is an unavoidable issue. Consequently, facilitating the separate production of ozone and nitrogen oxides is the primary requirement for achieving the desired plasma performance for specific purposes, yet it is poorly studied. Here, we report the chemical interplay among ozone and nitrogen oxides (<I>i.e</I>., NO, NO<SUB>2</SUB>, NO<SUB>3</SUB>, N<SUB>2</SUB>O<SUB>4</SUB>, N<SUB>2</SUB>O<SUB>5</SUB>) in air-based plasmas using surface dielectric barrier discharge (DBD) actuators as a reference plasma. A gas-tight chamber containing a DBD apparatus was designed for in-situ optical absorption spectroscopy to measure the concentrations of the chemicals. The temporal evolution of each chemical was successfully observed, and a rapid change in the plasma-chemistry mode (<I>i.e</I>., O<SUB>3</SUB>- to NO<SUB>2</SUB>-dominant mode) was clearly demonstrated. As a control parameter, the gas temperature, which ranged from 25 °C to 250 °C, was set in separate experiments. As the gas temperature was increased, ozone decomposed faster, while NO<SUB>2</SUB> became a dominant chemical species in the reactor earlier. All experimental results were compared with zero-dimensional modeling results, and the interplay among ozone and nitrogen oxides in air plasma was qualitatively analyzed. The gas temperature, which can be influenced by ohmic heating of the plasma itself, convective cooling from external or internal gas flow, or external settings, should be carefully considered for future study and commercialization.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Experimental observation of an interplay among O<SUB>3</SUB> and nitrogen oxides in air plasma. </LI> <LI> Rapid transition of the plasma-chemistry mode (O<SUB>3</SUB>-to-NO<SUB>2</SUB> dominant mode transition). </LI> <LI> Discussion in terms of chemical reaction set using zero-dimensional modelling. </LI> <LI> Effect of gas temperature on chemical characteristics of air plasmas. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Surface Modified Glass-Fiber Effect on the Mechanical Properties of Glass-Fiber Reinforced Polypropylene Composites

( Sanghoo Park ),( Su-jong Kim ),( Eun Seob Shin ),( Seung Jun Lee ),( Beom Mo Kang ),( Kyu-hwan Park ),( Seheum Hong ),( Seok-ho Hwang ) 한국고무학회 2019 엘라스토머 및 콤포지트 Vol.54 No.3

To improve the mechanical properties of glass-fiber-reinforced polypropylene (PP) composites through interfacial adhesion control between the PP matrix and glass fiber, the surface of the glass fiber was modified with PP-graft-maleic anhydride (MAPP). Surface modification of the glass fiber was carried out through the well-known hydrolysis-condensation reaction using 3-aminopropyltriethoxy silane, and then subsequently treated with MAPP to produce the desired MAPP-anchored glass fiber (MAPP-a-GF). The glass-fiber-reinforced PP composites were prepared by typical melt-mixing technique. The effect of chemical modification of the glass fiber surface on the mechanical properties of composites was investigated. The resulting mechanical and morphological properties showed improved interfacial adhesion between the MAPP-a-GF and PP matrix in the composites.

Plasma-Functionalized Solution: A Potent Antimicrobial Agent for Biomedical Applications from Antibacterial Therapeutics to Biomaterial Surface Engineering

Park, Joo Young,Park, Sanghoo,Choe, Wonho,Yong, Hae In,Jo, Cheorun,Kim, Kijung American Chemical Society 2017 ACS APPLIED MATERIALS & INTERFACES Vol.9 No.50

<P>Deadly diseases caused by pathogenic bacteria and viruses have increasingly victimized humans; thus, the importance of disinfection has increased in medical settings as well as in food and agricultural industries. Plasma contains multiple bactericidal agents, including reactive species, charged particles, and photons, which can have synergistic effects. In particular, the chemicals formed in aqueous solution during plasma exposure have the potential for high antibacterial activity against various bacterial infections. Here, we report the antibiotic potency of plasma-treated water (PTW). To illustrate the applicability of PTW for disinfecting biological substances, an Escherichia coli biofilm was used. We sought to identify the chemical species in PTW and investigate their separate effects on biofilm removal. Dielectric barrier discharge in ambient air was used to prepare the PTW and treat the biofilm directly. Hydrogen peroxide, ozone, and nitrites were identified as the long-lived reactive species in the PTW, whereas hydroxyl radicals and superoxide anions were identified as the short-lived reactive species in the PTW; all these species showed an ability to disinfect in biofilm removal.</P>

Effect of Microstructural Factors on Fatigue and Fatigue Crack Propagation Behaviors of Mill-Annealed Ti-6Al-4V Alloy

Park, Sanghoo,Kim, Sumin,Lee, Daeun,Ahn, Soojin,Kim, Sangshik The Korean Institute of Metals and Materials 2018 대한금속·재료학회지 Vol.56 No.12

Development of optical emission uniformity diagnostics for multiple meter size plasmas

Sanghoo Park,Juhyeok Jang,Wonho Choe 한국표면공학회 2013 한국표면공학회 학술발표회 초록집 Vol.2013 No.11

상시수요관리 시행 시간대에 따른 전력 사용 패턴 변화

박상후(Park Sanghoo),최승환(Choi Seunghwan),고종민(Ko Jongmin),노재구(Noh,Jaekoo) 대한전기학회 2011 대한전기학회 학술대회 논문집 Vol.2011 No.7

다수의 모바일 기기 사용 상황 내 멀티태스킹 양상 분석

박상후(Sanghoo Park),김상미(Sangmi Kim),한승미(Seungmi Han) 한국HCI학회 2014 한국HCI학회 학술대회 Vol.2014 No.12

최근 스마트폰 중심의 모바일 기기 사용이 보편화되고 사물인터넷을 기반으로 한 다양한 스마트 모바일기기가 등장하고 있다. 이에 따라 모바일 기기를 활용하는 사용자들은 여러 기기와 애플리케이션을 동시에 사용하면서 언제 어디서나 원하는 작업을 수행할 수 있게 되었다. 이에 따라 본 연구에서는 다양한 모바일 기기를 활용할 때 사용자들은 어떠한 방식으로 멀티태스킹을 하는지, 그리고 어떠한 기준에 의해 여러 멀티태스킹 양상이 나타나는지를 탐색적으로 알아보고자 질적 연구를 수행하였다. 특히 20-30 대의 스마트폰, 랩톱 및 태블릿 등 다양한 모바일 기기를 사용하는 사용자 19 명을 대상으로 개인 심층 인터뷰를 진행하였고 수집된 자료들은 근거 이론 기법을 활용하여 분석하였다. 그 결과 사용하는 모바일 기기의 수, 기기의 특성, 기기의 사용 목적, 멀티태스킹을 구성하는 작업 간 연관성 등이 최근의 모바일 기기 사용환경에서의 멀티태스킹에 중요한 영향을 미치고 있음을 확인할 수 있었으며, 이때의 멀티태스킹은 단일기기-분절화된 멀티태스킹, 다중기기-분절화된 멀티태스킹, 다중기기-통합된 멀티태스킹 양상으로 나타나는 것을 확인하였다. 연구 결과를 바탕으로 향후 사물인터넷 시대에서 발생할 수 있는 여러 모바일 기기 기반의 멀티태스킹 관련 연구의 이론적 확장과 실용적 활용방안에 대하여 논의해 보았다. As a mobile device including smartphones has become one of necessities in everyday life, people are enabled to work on any tasks they want at any time. Moreover, due to mobility and advanced computing system in mobile devices, the users have been habituated to multi-tasking on the devices. We conducted a qualitative study in order to explore multitasking behaviors within the context of using multiple mobile devices. With 19 mobile device users, individual in-depth interviews were carried out. The data from the interviews were analyzed based on grounded theory. In conclusion, various factors such as the number and characteristics of devices, relationships between the tasks have influences on multi-tasking behaviors. Implications and limitations of this study were presented.

AAL(Ambient Assisted Living) 기반 스마트 공동주택 거주자에 적합한 헬스케어 서비스 개발을 위한 사용자 심층 조사

박상후(Park, Sanghoo),노지영(Noh, Geeyoung),신주영(Shin, Juyoung),문유정(Moon, Yujeong),이종선(Lee, Jongsun) 한국디자인지식학회 2015 디자인지식저널 Vol.34 No.-

본 연구의 목적은 AAL(Ambient Assisted Living)기반 스마트 공동주택 거주자에 적합한 헬스케어 서비스 개발을 위한 수요 분석 및 서비스 기획을 제시하고자 함이다. 이를 위하여 Pre-Test와 Workshop을 진행하여 효율적인 심층 인터뷰 진행 방법과 기본적인 니즈 분석을 하였으며, 최종적으로는 8회에 걸친 심층 인터뷰로 연령대별로 남성 그룹과 여성 그룹을 나누어 헬스케어 서비스에 대한 의견이 어떻게 다른 지에 대하여 비교 분석하였다. 본 연구의 결과를 바탕으로 다음과 같은 결론을 내릴 수 있다. 첫째, 스마트 공동주택을 기획함에 있어 남성과 여성의 니즈 차이를 고려하여야 한다. 둘째, 스마트 공동주택을 기획함에 있어 다양한 연령대의 니즈 차이를 고려하여야 한다. 마지막으로, 스마트 공동주택을 기획함에 있어 IT기기 숙련도를 고려하여야 한다. 본 연구는 정부과제의 1차년도 과정으로 향후 연구로써 새로운 스마트 공동주택 헬스케어 서비스를 기획하고 이를 구현해나가는 작업의 선행 과정으로써 사용자 심층 조사를 하였다는 점에서 의의가 있다. This study aims at presenting the results of service-related demand analysis that may be useful in developing a healthcare service system tailored to the needs of residents of Ambient Assisted Living(AAL) based smart apartments. To this end, a pre-test was conducted and a workshop was held to explore an efficient in-depth interview method and perform a basic needs analysis. Finally, in-depth interviews were conducted in eight groups (four age groups and gender subgroups for each age group) in order to compare and analyze the age and gender specific opinions about healthcare service. From the results of this study, the following conclusions could be drawn. First, gender specific needs should be taken into consideration in planning a smart apartment. Second, age dependent needs should be taken into consideration in planning a smart apartment. Finally, IT device application skills should be taken into consideration in planning a smart apartment. This study is significant in that it conducted an in-depth user interview survey as a preliminary step towards future study on smart apartment healthcare service planning and implementation as the first-year task of the government agenda.

플라즈마 공정 개발을 위한 인간과 AI의 협업: Human First-Computer Last strategy

박상후(Sanghoo Park),김종찬(Jongchan Kim) 한국진공학회 2024 진공 이야기 Vol.11 No.1

Historically, Plasma technology has played a crucial role in the advancement of semiconductor processes, being utilized across various stages of manufacturing. A symbiotic relationship with artificial intelligence(AI) technologies is now opening an era of accelerated innovation in semiconductor technology. Ironically, even today, the development and management of plasma processes in industries largely rely on the trial-and-error approach of trained engineers and their intuition and experience. This reliance increases the cost of developing plasma processes, which may in turn cause a bottleneck to building semiconductor chips. This paper introduces a Human First–Computer Last strategy that reduces the costs of plasma process development, recently suggested by Lam Research. The study shows how human experience and intuition can positively influence the utilization of AI, especially good for the high degree of freedom characteristic of plasma processes. The findings advocate that, even as plasma processes evolve to levels beyond the grasp of current knowledge, basic learning and domain experience will remain critical. This insight suggests a nuanced approach to integrating AI within plasma process development, emphasizing the complementarity of human expertise and computational algorithms to optimize efficiency and innovation in semiconductor manufacturing.

Structural Analyses of total Anionic Cyclosophoraoses Synthesized by Rhizobium meliloti 2011

Dong-huyk Seo, Sanghoo Lee, Hey-lin Park, Dong-Heui Yi, EunJung Ji, Dae-Ho Shin, Seunho Jung 대한화학회 2002 Bulletin of the Korean Chemical Society Vol.23 No.6