Eco-friendly Cellulose nanofibril-Polypropylene Nano-composites

박예림,서영수 한국공업화학회 2020 한국공업화학회 연구논문 초록집 Vol.2020 No.-

Polypropylene (PP) is one of the most popular thermoplastic polymers used in industry including automotive company. To improve physical properties, PP is often used in combination with fillers such as a glass or carbon fiber. Because eco-friendliness issues such as reducing weight, recyclability, and biodegradability have been attracting attention, cellulose nanofibril (CNF) having excellent tensile strength similar to Kevlar(~ 3.6 GPa) is emerging as a filler instead of glass or carbon fiber. Still, few obstacles should be overcome for using it as a filler such as dispersing in hydrophobic PP and oxidizing in the melt mixing process. In this study, CNF was surface-modified with inorganic nanoparticles exhibiting good dispersion in PP and thermal stability where the amount of the particles was tried to be minimized for reducing weight. The mechanical properties of the composite were analyzed according to ASTM standards. The rheological propertiy was measured using a rotatable rheometer

에탄 탈수소방향족화에서 CNT 생성이 CoZn/HZSM-5 촉매의 비활성화에 미치는 영향

박예림,김상윤,주나영,이관영 한국에너지학회 2022 한국에너지공학회 학술발표회 Vol.2022 No.10

Assessing Soil Organic Carbon Stock and Stability in Volcanic Grasslands: Implications for Climate Change Mitigation Potential and Management Levels

박예림,유가영,현준기,정종성 한국토양비료학회 2023 한국토양비료학회지 Vol.56 No.4

Volcanic grassland has a high soil organic carbon (SOC) stock, making it important for climate change mitigation. This study analyzed SOC stock in volcanic grassland soils and assessed the potential of volcanic grassland as a carbon sink by identifying the effect of management on SOC stock and stability. Soil samples in Jeju were collected from eight sites of generally well-managed grasslands (nominally-managed grassland, NG: applying fertilizer once annually and plant cover rate is 60 - 80%), which is considered as the representative SOC stock of volcanic grassland soil. To identify whether SOC stock increased by improved management (improved grassland, IG: applying fertilizer twice annually and plant cover rate is over 80%), soil samples were collected from two IG sites. Soil samples from NG and IG were analyzed for their SOC stock and stability using SOC fractionation. Our results revealed that the SOC stock of NG was 95 ton C ha-1. It was 19% higher than the default value (80 ton C ha-1) for grassland corresponding to a warm temperate climate suggested by IPCC 2006 Guidelines for National Greenhouse Gas Inventories. The SOC stock in the IG (150 ton C ha-1) was significantly higher than NG (95 ton C ha-1) by 58%. Especially, most of the increased SOC stock was stored in the stable fraction of Micro_POC (particulate organic carbon in microaggregate). Consequently, improved management of volcanic grassland in Jeju has the potential to offset 29% of carbon emissions from Jeju’s agricultural sector, underlining the importance of volcanic grasslands in climate change mitigation strategies.

High strength, Light-weighted and Recyclable Cellulose Nanofibril (CNF)-Polypropylene Composites

박예림,유제승,박범수,서영수 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.1

Polypropylene (PP), a thermoplastic polymer with durability, impact resistance, and heat resistance, is currently used in many applications such as automobile elements as a form of composite with glass fibers. Recently, the importance of reducing weight of, especially, electric vehicles and recycling of automobile materials have become important issues. The introduction of cellulose nanofibrils (CNF) as a replacement for glass fibers in PP composites is drawing attention to address both issues. Much efforts have been made to improve the dispersion and thermal oxidation of CNF during melt mixing processes at high temperatures of ~ 200°C. In this study, CNF was surface-modified with inorganic materials to improve dispersion and suppress thermal oxidation. Mechanical properties and recyclability of the composite will be presented.

중형냉각재상실사고시 안전주입펌프 단일고장 및 임계유동 모델 민감도 분석

박예림 한국에너지학회 2023 한국에너지공학회 학술발표회 Vol.2023 No.10

일본 휴대전화 산업의 쇠퇴원인과동형화 과정 분석- 가라케(ガラケー)와 수직통합모델을 중심으로 -

박예림 한양대학교(ERICA캠퍼스) 일본학국제비교연구소 2023 비교일본학 Vol.59 No.-

본고에서는 일본 휴대전화 산업 환경의 추이와 쇠퇴 요인, 그리고 그 배경에서 작용한 동형화(isomorphism) 과정에 대해 분석한다. 일본 휴대전화 산업의 라이프 사이클을 통해 번영기를 지나 현재는 쇠퇴기가 분명하며, 일본 휴대전화 산업의 쇠퇴 요인을 분석하기 위한 이론틀인 동형화를 바탕으로 그 쇠퇴요인에 대해 살펴본다. 첫번째 쇠퇴요인은 가라케의 독자적인 통신규격과 기술이며, 두 번째는 이동통신업체 주도의 수직통합모델이다. 이러한 독 자적인 통신규격의 도입과정과 수직통합모델의 중심에는 정부와 민영화 이후의 NTT 도코모 가 존재했으며, 이 과정에서 정부 주도의 강제적 동형화와 이후 이동통신업체의 벤치마킹의 대상이 된 NTT 도코모 중심의 모방적 동형화가 종합적으로 발생했다. 일본만의 독자적인 통신규격과 독특한 수직통합모델은 일본 휴대전화 산업을 명백히 쇠퇴시킨 요인이며 이를 ‘동형화’가 촉진한 것이라 할 수 있다. This paper analyzes the trend and decline factors of the Japanese mobile phone industry environment and the isomorphism process that worked in the background. Furthermore, we examine the decline factors based on isomorphism, a theoretical framework for analyzing the decline factors of the Japanese mobile phone industry. The first decline factor is Galapagos ke-tai's independent mobile phone standards and technologies, the second is a vertically integration led by a mobile carrier. At the center of these decline factors were the government and NTT DoCoMo after privatization. In this process, government-led “Coercive isomorphism” and “Mimetic process” centered on NTT DoCoMo, which was later the subject of benchmarking by mobile carriers, occurred comprehensively. Japan's own mobile phone standards and unique vertical integration are factors that clearly declined the Japanese mobile phone industry, and it can be said that ‘isomorphism’ promoted this.

Cellulose Nanofibril (CNF)-polymer Composite : Effects of Surface Modification on Thermal and Mechanical Properties

박예림,서영수 한국고분자학회 2020 한국고분자학회 학술대회 연구논문 초록집 Vol.45 No.2

기관지 생검이 진단에 도움이 된 Candida albicans 폐렴 1예

박예림,송은희,박윤규,김학수,임재민,강길현,우준희 대한의진균학회 2015 대한의진균학회지 Vol.20 No.3

Candida species is indigenous fungus of healthy individuals, and frequently found in sputum culture. Candida isolation from the respiratory tract is not generally considered as a marker of lung infection, and definitive diagnosis of Candida pneumonia is confirmed by tissue biopsy. A few cases of Candida pneumonia pathologically confirmed by transthoracic needle aspiration of mycetoma have been reported. In Korea, a case of Candida pneumonia diagnosed by bronchial washing and blood culture was reported, but there is no case report diagnosed by biopsy. We report a case of Candida pneumonia diagnosed by endobronchial biopsy, and antifungal therapy resulted in successful resolution of the pneumonia.

일본 경자동차 시장의 현황과 산업적 특징

박예림 한림대학교 일본학연구소 2023 翰林日本學 Vol.0 No.42

Since the 2000s, Japan has been regarded as a low-growth country, and there are growing concerns that some industries will be eliminated because they cannot keep up with the global trend. This study focuses on “Japan’s light vehicle (Kei-car)” and revealed the cause and effect of the industry’s background and market characteristics of Japan’s light vehicle (Kei-car). As for the characteristics of the market, it was found that there were huge domestic markets, the positioning of domestic automobile brands (so-called Sumiwake), and the characteristics of Japanese consumers. Industrial characteristics of Japan’s Kei-car include independent standards, implicit regulations by manufacturers, the existence of systems, tax and insurance benefits, and past government policies. 2000년대 이후 일본은 저성장 국가라 평가받고 있으며, 일부 산업들에 글로벌 흐름에 뒤처져 도태되는 것이 아닌가 하는 우려의 목소리도 커지고 있다. 본 연구는 그러한 산업 중 특히 일본 내에서 입지를 굳힌 ‘경자동차’에 주목하여 시장의 현황과 산업의 특징을 밝힌다. 경자동차 시장의 특징으로는 무역의 부재와 탄탄한 내수의 존재, 경자동차 메이커의 치열한 경쟁 구도와 외부 규모의 경제 효과 그리고 고령화 사회의 영향으로 인한 고령 소비층의 두각과 일본 소비자들의 특성이 있다. 이어서, 경자동차의 산업적 특징에서는 독자적 규격과 메이커의 암묵적인 규제, 세제 및 보험 제도의 혜택, 그리고 정부 정책인 국민차 구상을 살펴보았다. 해외 자동차 메이커는 일본의 경자동차 시장에 대해 비관세 장벽이 형성되어 수출이 어렵고 일본 내에서만 판매되는 독특한 산업이라 비난했지만, 일본 경자동차 메이커와 국민의 관점에서는 효자 산업이자 경제적으로 바람직한 현상임이 분명하다. 이와 같은 환경에 처한 산업군을 발굴하고 성장시킬 수 있다는 점에서 경자동차뿐 아니라 일본 내 갈라파고스 산업 연구는 앞으로도 주목할 필요가 있다.

플리커 데이터의 텍스트마이닝을 통한 서울방문 외국인 관광객의 서울 이미지 분석

박예림,강영옥,김동은,이주윤,김나연 대한공간정보학회 2019 대한공간정보학회지 Vol.27 No.1

본 연구에서는 소셜 네트워크 데이터인 플리커를 활용하여 서울시와 서울시 내 주요 관광지별 이미지를 분석하고자 하였다. 이를 위해 2015년 1월1일부터 2017년 12월 31일까지 서울범위 내 게시된 플리커 데이터를 수집하고, 이 가운데 관광객으로 추정된 사용자의 플리커를 토대로 서울시내 11개의 주요관광지를 도출하였다. 플리커 내 태그와 제목 텍스트를 대상으로 텍스트마이닝을 수행하였으며, 텍스트마이닝 방법으로는 워드클라우드, 동시출현 네트워크, 토픽모델링 기법을 사용하였다. 워드클라우드 및 동시 출현 네트워크를 작성한 결과 서울 방문 관광객의 주요 관광 요소 및 관심사는 고궁, 번화가, 밤 문화, 시장 및 음식에 집중되어 있음을 알 수 있었다. 토픽 모델링을 통해 12개의 주요 토픽을 선정할 수 있었으며, 11개 관광지별 주로 언급되는 단어와 주요 토픽을 정리하여 관광지별 이미지를 확인할 수 있었다. This paper aims to examine the Seoul images of foreign tourists who visit key attractions in Seoul by using Flickr text data. We collected Flickr data that foreign tourists have posted in the area of Seoul for three years, that is, from January 1st in 2015 to December 31st in 2017. We drew 11 key attractions in Seoul based on Flickr data of users who are presumed on foreign tourists. With the results of Word Cloud and Co-occurance Network, we drew a conclusion that foreign tourists in Seoul are mainly interested in palace, downtown, local markets, and restaurants and bars where they could enjoy their night life. We drew 12 key topics that foreign travelers surfaced on their strong interests by using topic modeling. We think that the findings of this study can provide the features of Seoul that foreign travelers have shown and can be a baseline data of enhancing Seoul tourism with meaningful insights in the future.