자동차 언더커버의 유니소재화 적용 및 전과정평가

윤혜리(Hyeri Yun),박유성(Yoosung Park),유미진(MiJin Yu),배하나(Hana Bae),이한웅(Hanwoong Lee) 한국청정기술학회 2017 청정기술 Vol.23 No.3

국내외 자원순환규제 대응 및 온실가스 저감을 위해 자동차산업에서는 부품의 소재 종류의 수를 줄여 재활용률 목표치를 달성하고, 폐기단계 또는 제조단계에서 발생하는 불량 및 스크랩을 순환자원으로 재활용하는 노력을 하고 있다. 또한 기존제품의 성능은 유지하면서 온실가스 저감 목표치를 달성하기 위해 부품 경량화를 추진하고 있다. 기존제품의 폐기단계에서 100% 소각을 하던 제품을 개선제품에서는 제조전단계와 제조단계에서 발생하는 스크랩, 불량을 수거하여 90%의 재활용이 가능하도록 개선했다. 또한 기존제품 대비 56% 경량화를 통해 연비 개선효과를 나타냈다. 본 연구에서는 자동차 언더커버를 대상으로 유니소재화 제품 개발 적용가능성에 대한 사전평가를 실시하고, 개발된 시제품의 전과정평가를 통해 기존제품과 개발된 시제품의 환경영향값을 비교, 분석하고자 한다. In response to national and international regulations for resource circulation and to reduce greenhouse gas emissions, the automotive industry has tried to reuse scrap parts and defective products produced in the disposal or production stages as recycled resources. Attempts have been made to reach the target recycling rate by reducing the number of material types required for each part. Moreover, in order to achieve greenhouse gas reduction targets while maintaining the performance of existing products, lighter components are being developed. Existing products were 100% incinerated at the disposal stage, but the uni-materialized products were improved to be possible that it could be recycled 90% through scraps and the defective product in the pre-production and production stage. It also appears that the fuel efficiency improves through 56% lightweight compared to the existing product. In this paper, a preliminary assessment is conducted on the applicability of uni-materialized product development of car parts. The environmental impact values of existing products and developed prototypes are compared and analyzed through life cycle assessment.

Protaetia brevitarsis Protects PC12 Cells against Amyloid Beta Peptide25-35-Induced Cell Injury

Hyeri Kim,Seonah Lee,Eun-Young Yun,Jae-Sam Hwang,Mok-Ryeon Ahn,Oh-Yoen Kim,Mira Jun 한국식품영양과학회 2014 한국식품영양과학회 학술대회발표집 Vol.2014 No.10

Infectivity of Coronavirus Disease 2019: A Prospective Cohort Study in the Korean Metropolitan Area

Seok Hyeri,Lim Seungkwan,Kim Ji-Yeon,Park Chul Hee,Kim Joon Ho,Woo Myoung Lyeol,Won Hyejin,Kang Yu Min,Oh Hong Sang,Song Kyoung-Ho,Jung Yun Jung,Kim Tark,Jo Soonam,Choi Won Suk 대한의학회 2022 Journal of Korean medical science Vol.37 No.14

Background: Although several characteristics of coronavirus disease 2019 (COVID-19), an ongoing pandemic disease, have been identified, data on the infectivity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are limited. Methods: This prospective cohort study was conducted to analyze the infectivity of SARSCoV-2 based on data of all patients diagnosed with COVID-19 confirmed using real-time polymerase chain reaction test from January to April 2020 in Gyeonggi-do, the largest province in Korea. Results: Of the 502 patients, 298 consisting of 106 clusters with 5,909 contacts were included. Of these, 277 (93.0%) were symptomatic, and the most common symptoms were cough, fever, sputum, sore throat, and headache. A total of 94 patients (31.5%) had pneumonia, while 8 (2.7%) died during the follow-up period. The secondary attack rate (SAR) in the study population was 3.5% (204/5,909). In exposure settings, the SAR was higher in religious gathering (13.5% [95% confidence interval, 10.7–16.8%]), workplaces (8.49% [95% CI, 6.08–11.74%]), and schools (6.38% [95% CI, 3.39–11.69%]) than in health care facilities (1.92% [95% CI, 1.45–2.55%]). Sore throat at any period, dyspnea at diagnosis or any period, lower cycle threshold value in the lower respiratory tract samples, leukocytosis, and higher bilirubin levels were associated with higher infectivity of COVID-19. The presence of symptoms was not related to the infectivity. Conclusion: In establishing the infection control strategies for COVID-19, the variables associated with high infectivity may be considered.

Optical Properties of Tetrahydrofuran Clathrate Hydrates with Polyvinylpyrrolidone (THF + H₂O + PVP) Revealed by Terahertz (THz) Time-Domain Spectroscopy

Kang, Hyery,Koh, Dong-Yeun,Ahn, Yun-Ho,Jung, Seonghoon,Park, Jaehun,Lee, Jaehyoung,Lee, Huen American Chemical Society 2015 Journal of chemical and engineering data Vol.60 No.2

<P>Terahertz time-domain spectroscopy (THz-TDS) was used to observe the tetrahydrofuran (THF) clathrate hydrate system with dosage of polyvinylpyrrolidone (PVP) with three different average molecular weights (10 000 g/mol, 40 000 g/mol, and 360 000 g/mol). Distinct footprints of phase transition in the THz region (0.4 THz to 2.2 THz) were analyzed and absorption coefficients and complex refractive indices are obtained and compared in the temperature range of 253 to 288 K. Along with the optical properties, ring breathing and stretching modes for different molecular weights of PVP in THF hydrate are analyzed by Raman spectroscopy.</P>

백두산의 제4기 폭발성 분화에 의한 광역 화산재

김혜리(Hyeri Kim),윤성효(Sung-Hyo Yun),이정현(Jeonghyun Lee),장철우(Cheolwoo Chang) 대한지질학회 2021 대한지질학회 학술대회 Vol.2021 No.10

일본, 러시아, 대한민국 등에 의하여 시행된 동해 해저퇴적물의 해저시추코어에 대한 연구 결과들에서 백두산 화산 기원으로 해석할 수 있는 다수의 테프라(화산재/화산유리)가 인식되었다. 이들은 백두산의 폭발성 분화(explosive eruption)로 생성된 분연주와 화산재 구름이 제트기류 및 편서풍을 타고 동해 쪽으로 확산되면서 대기 중에서 낙하된 강하화산재(fallout ash)로부터 기원된 것으로 해석된다. 규장질 마그마의 플리니형 분화로 형성된 분연주와 화산재구름에서 낙하하는 화성쇄설물은 분화구 근처에서는 주로 부석의 형태로, 원거리에서는 화산재(유리샤아드)의 형태로 퇴적된다. 밀레니엄 분화 산물인 B-Tm (Baegdusan-Tomakomai) tephra에 대한 분포도가 Machida & Arai(1983)에 의해 작성되었으며, Utkin (2014)는 동해 해저 표면에 떨어진 B-Tm층의 총 질량과 입자 크기별 질량 분포를 제시하였다. Derkachev et al . (2019)은 동해 해저 퇴적물에서 발견된 여러 층준의 백두산의 폭발성 분화에 의한 테프라 분포도를 작성하였다. 이러한 테프라의 분포를 실시간 유사기상장에서 USGS의 ash3d 프로그램으로 수치모의하여 나타내어 보면, 동해쪽으로 화산재가 확산되거나 또는 Machida and Arai (1983)의 분포도와 유사하게 나타난다. 현재까지 동해 해저 및 일본열도에서 알려진 백두산 기원으로 추정되는 테프라는 B-Og (Baekdusan-Oga tephra-448 ka), B-Ky2 (Baekdusan-Kita Yamato 2 tephra-196 ka), B-Ky1 (Baekdusan-Kita Yamato 1 tephra-130 ka), B-Ym(Baekdusan-Yamato tephra-85.8 ka), B-Sado (Baekdusan- Sado-oki tephra-67.6 ka) B-J (Baekdusan-Japan Basin tephra-50.6 ka), B-Sg-42 (Baegdusan-Suigetsu-42 tephra-42.5 ka), B-Un1 (Baekdusan-Unknown tephra-38.3 ka), B-V (Baekdusan- Vladivostok tephra-24.5 ka), B-Sg-08 tephra (Baegdusan- Suigetsu-08 tephra-8.1 ka), B-Tm (Baekdusan-Tomakomai tephra-946 AD) 등이 알려져 있다. 이들 테프라들은 화학조성상 대부분 규장질이며, B-Og와 B-Ym은 조면암질, B-Ky 2와 B-Un1은 유문암질, 그 외 B-Ky1, B-Sado, B-J, B-V, B-Tm은 조면암에서 유문암(SiO2 함량: 62.5 wt.%에서 77.2 wt%)에 이르는 조성 범위를 나타낸다. Na₂O-K₂O성분도(MIddlemost, 1975)에서는 대부분 potassic series에 속하나, 일부 sodic series에도 도시된다. Al₂O₃-(Fe₂O₃+FeO) 분류도(MacDonald, 1974)에서 대부분 코멘다이트(comendites, comenditic trachytes) 영역에 도시되나, 일부(B-Sado, B-J, B-V 등) 판테르라이트(pantellerites, pantelleritic trachtyes) 영역에도 도시된다. B-Tm의 확산 범위는 기존 알려진 것보다 더 넓은 영역에 영향을 미친 것으로 해석된다. 백두산으로부터 200 km에서 1,000 km 거리의 동해 해저와 일본 본토에 낙하된 광역 화산재들은, 백두산이 플리니형의 폭발성 분화로 만들어낸 분연주와 화산재구름이 제트기류와 편서풍으로 타고 동해 바다 위로 이동하면서 낙하하여 퇴적된 것으로, 제4기에 백두산에서의 화산폭발지수(Volcanic Explosivity Index) 4 이상의 폭발적 대분화를 지시하는 것으로 해석된다. 이들 테프라 연대는 백두산 일원에서는 현재까지 알려지지 않은 연대들이다.

Ultrasound findings of subpial hemorrhage in neonates

Lim Yun-Jung,Shin Su-Mi,Hyeri Kim,Mi Lim Chung,Seok Hahn,Cho Yeon Jin 대한초음파의학회 2023 ULTRASONOGRAPHY Vol.42 No.2

Purpose: Subpial hemorrhage (SPH) is a subtype of intracranial hemorrhage characterized by damage to the adjacent brain parenchyma. The aim of this study was to describe the sonographic features of SPH in neonates. Methods: The cranial ultrasound (US) findings of neonates with SPH confirmed by brain magnetic resonance imaging (MRI) were analyzed retrospectively. Initial and follow-up US and MRI scans were reviewed by two pediatric radiologists who were blinded to both clinical history and outcomes. The US features were compared with the MRI findings. Results: Sixteen patients were included (median gestational age, 38 weeks; range, 26 to 40 weeks; 69% term). SPH was detected most often in the temporal lobe (63%), and multiple SPHs were found in seven of 16 neonates, based on MRI. Acute SPH with an underlying venous infarct (UVI) was detected on US in 15 of 16 patients: small or large fan-shaped hyperechoic lesions (n=7 and 4, respectively) and gyriform hyperechoic lesions (n=4). The sonographic yin-yang sign was observed in three of the four large fan-shaped SPH cases. The accompanying findings on US were intraventricular hemorrhage (four out of six MRI-confirmed cases), and concurrent periventricular venous infarcts (five out of nine MRI-confirmed cases). In five patients, subpial cysts were observed on follow-up US or MRI (n=4 and n=4, respectively). Conclusion: Acute SPH with UVI can appear as a peripheral fan-shaped or gyriform hyperechoic lesion on cranial US. SPH can be detected and suspected based on the US features of SPH with the accompanying findings.

동해 해저에서 발견된 백두산의 폭발적 분화에 의한 강하 테프라들

김혜리(Hyeri Kim),윤성효(Sung-Hyo Yun),이정현(Jeonghyun Lee),장철우(Cheolwoo Chang) 대한지질학회 2020 대한지질학회 학술대회 Vol.2020 No.10

IoT 기반의 비전 및 원격제어 소형 이동 로봇 시스템

전윤채(Yun Chae Jeon),최혜리(Hyeri Choi),윤기철(Ki-Cheol Yoon),김광기(Gwang Gi Kim) 한국멀티미디어학회 2021 멀티미디어학회논문지 Vol.24 No.2

Intracavity Conformational Changes in Clathrate Hydrates

Ahn, Yun-Ho,Lim, Hyung-Kyu,Kang, Hyery,Kim, Hyungjun,Cha, Minjun,Shin, Kyuchul,Lee, Huen American Chemical Society 2016 The Journal of Physical Chemistry Part C Vol.120 No.31

<P>Acyclic hydrocarbon molecules favor the gauche or cis conformation, which are more stable in terms of molecular geometry when they are enclathrated in clathrate hydrates. Once they are captured, they maintain their conformations in the hydrate cavities. However, on the basis of Raman spectra and density functional theory (DFT) calculations, we observed conformational changes of an acyclic guest molecule (3-buten-2-one) occurring in the hydrate cavities induced by intercavity electron transfer after gamma-irradiation. This phenomenon is also accompanied by an enhanced thermodynamic stability of the clathrate hydrate phases. These results contribute to an understanding of the complex physicochemical properties of clathrate hydrates and suggest practical application for hydrate-based gas storage and separation.</P>

국립기상과학원 플럭스 관측 자료 기반의 JULES 지면 모델 모의 성능 분석

김혜리(Hyeri Kim),홍제우(Je-Woo Hong),임윤진(Yoon-Jin Lim),홍진규(Jinkyu Hong),신승숙(Seung-Sook Shin),김윤재(Yun-Jae Kim) 한국기상학회 2019 대기 Vol.29 No.4

Based on in-situ monitoring data produced by National Institute of Meteorological Sciences, we evaluated the performance of Joint UK Land Environment Simulator (JULES) on the surface energy balance for rice-paddy and cropland in Korea with the operational ancillary data used for Unified Model (UM) Local Data Assimilation and Prediction System (LDAPS) (CTL) and the high-resolution ancillary data from external sources (EXP). For these experiments, we employed the one-year (March 2015~February 2016) observations of eddy-covariance fluxes and soil moisture contents from a double-cropping rice-paddy in BoSeong and a cropland in AnDong. On the rice-paddy site the model performed better in the CTL experiment except for the sensible heat flux, and the latent heat flux was underestimated in both of experiments which can be inferred that the model represents flood-irrigated surface poorly. On the cropland site the model performance of the EXP experiment was worse than that of CTL experiment related to unrealistic surface type fractions. The pattern of the modeled soil moisture was similar to the observation but more variable in time. Our results shed a light on that 1) the improvement of land scheme for the flood-irrigated rice-paddy and 2) the construction of appropriate high-resolution ancillary data should be considered in the future research.