기상 불소화법을 이용한 WO3-xFx 광촉매의 합성 및 광분해 특성

이혜련 ( Hyeryeon Lee ),임채훈 ( Chaehun Lim ),이란은 ( Raneun Lee ),이영석 ( Young-seak Lee ) 한국공업화학회 2021 공업화학 Vol.32 No.6

In this research, fluorine doping was performed to enhance the photocatalytic activities of WO₃ which were measured using methylene blue dye. WO_3-xF_x photocatalyts were prepared by a vaper phase fluorination during a sintering for preparing WO₃ photocatalysts from a WCl₆ precursor. The bandgap energy of WO₃ photocatalysts decreased from 2.95 eV to 2.54 eV, and the oxygen vacancies site increased by about 55% after fluorine doping. In addition, the initial degradation efficiency of methylene blue showed that the fluorine doped sample showed a 6-fold increase in photocatalytic activities from 10% to 60% compared to that of the untreated sample. It is believed that fluorine is doped to reduce the band gap of photocatalysts, enabling the catalytic activity with low energy, and that oxygen vacancies-generated surface defects increase the visible light absorption region of WO₃ photocatalysts, thereby increasing photocatalytic activity. In this study, it was confirmed that fluorine-doped WO_3-xF_x photocatalysts with an excellent photocatalytic activity can be manufactured easily using a one-step vaper phase fluorination that does not require a post-treatment process.

So-Eum Type as an Independent Risk Factor for Irritable Bowel Syndrome: A Population-Based Study in Korea

Lee, Seung Ku,Yoon, Dae Wui,Yi, Hyeryeon,Lee, Si Woo,Kim, Jong Yeol,Kim, Jin Kwan,Hong, Jeong Hwa,Shin, Chol Mary Ann Liebert, Inc. Publishers 2014 Journal of Alternative & Complementary Medicine Vol. No.

<P>Objectives: It has been hypothesized that Sasang constitutional types (SCTs) have a specific hypoactive organ, which can account for vulnerability to related diseases or symptoms. This study examined the relationship between SCTs and irritable bowel syndrome (IBS). Design: Cross-sectional study in a population-based cohort study in Korea. Participants: 1362 individuals (705 men and 657 women) who participated in the Korean Genome and Epidemiology Study. Outcome measures: The participants were classified into SCTs by the integrated diagnostic model and asked about symptoms related to IBS using the Rome II criteria. Results: The prevalence of IBS differed significantly among the SCTs, with 33 (18.3%) of the So-eum (SE) type, 74 (9.9%) of the Tae-eum (TE) type, and 57 (13.2%) of the So-yang (SY) type having IBS. Even after adjustment for possible confounders, the SE type for both sexes continued to show 1.82-fold (95% confidence interval [CI], 1.05-3.16) excess odds of having IBS. Men with SE type had a 2.97 times (95% CI, 1.34-6.58) and a 2.50 times (95% CI, 1.15-5.47) significantly higher odds of having IBS than the TE and SY types, respectively. In analysis for the joint effect of SCT and psychological stress, the multivariate odds ratio of IBS was 3.21 (95% CI, 1.33-7.75) for the SE type and Psychological Well-Being Index-Short Form (PWI-SF) score (<27), and 5.83 (95% CI, 1.80-18.88) for the SE type and PWI-SF (>= 27) compared with the TE type and PWI-SF score (<27). Conclusions: The SE type of SCT is an independent risk factor for IBS. The findings support the hypothesis that persons with SE type are vulnerable to gastrointestinal diseases.</P>

GENERATION Y’S ONLINE ENGAGEMENT IN BUILDING BRAND LOYALTY THROUGH SOCIAL MEDIA

HyeRyeon Lee,Ge Xiao 글로벌지식마케팅경영학회 2018 Global Marketing Conference Vol.2018 No.07

As Internet use has increased, customers have become more active at sharing their travel opinions through social media regarding their experiences with service organizations. Social media has become a ubiquitous tool that enables customers to share their travel experiences. In particular, members of Generation Y are more likely to be active on social media and more likely to share their experiences online. Understanding Generation Y’s online customer engagement preferences on different social media platforms may help to enhance brand loyalty. Customer engagement (CE) has been attracting the attention of both practitioners and academics because it may help to enhance both brand loyalty and purchase decisions. Social media platforms have become a significant communication tool for both customers and service providers, creating an opportunity to engage with customers. Interacting with active customers on the right social media platform can increase direct bookings, building brand loyalty. Therefore, the purpose of this research is to examine Generation Y’s brand loyalty preferences through its members’ engagement with social media. The results of this research will expand understanding of Generation Y customers’ online engagement through social media. This research may also suggest how hotels are able to utilize social media platforms in order to encourage online engagement with Generation Y by building brand loyalty.

Determining optimal sleep position in patients with positional sleep-disordered breathing using response surface analysis

LEE, JUNG BOK,PARK, YOUNG HWAN,HONG, JUNG HWA,LEE, SEUNG HOON,JUNG, KI HWAN,KIM, JE HYUNG,YI, HYERYEON,SHIN, CHOL Blackwell Publishing Ltd 2009 Journal of sleep research Vol.18 No.1

<P>Summary</P><P>A lateral position (LP) during sleep is effective in reducing sleep disorder symptoms in mild or moderate sleep apnea patients. However, the effect of head and shoulder posture in LP on reducing sleep disorders has not been reported. In this study, effective sleeping positions and a combination of sleep position determinants were evaluated with respect to their ability to reduce snoring and apnea. The positions evaluated included the following: cervical vertebrae support with head tilting (CVS-HT), scapula support (SS), and LP. A central composite design was applied for response surface analysis (RSA). Sixteen patients with mild or moderate positional sleep apnea and snoring who underwent polysomnography for two nights were evaluated. Based on an estimated RSA equation, LP (with a rotation of at least 30°) had the most dominant effect [<I>P </I>= 0.0057 for snoring rate, <I>P </I>= 0.0319 for apnea–hypopnea index (AHI)]. In addition, the LP was found to interact with CVS-HT (<I>P </I>= 0.0423) for snoring rate and CVS-HT (<I>P </I>= 0.0310) and SS (<I>P </I>= 0.0265) for AHI. The optimal sleep position reduced mild snoring by more than 80% (i.e. snoring rate in the supine position was <20%) and the snoring rate was approximately zero with a 40° rotation. To achieve at least 80% reduction of AHI, LP and SS should be >30° and/or 20 mm respectively. To determine an effective sleep position, CVS-HT and SS, as well as the degree of the LP, should be concurrently considered in patients with positional sleep apnea or snoring.</P>

Tae-Eum Type as an Independent Risk Factor for Obstructive Sleep Apnea

Lee, Seung Ku,Yoon, Dae Wui,Yi, Hyeryeon,Lee, Si Woo,Kim, Jong Yeol,Shin, Chol Hindawi Publishing Corporation 2013 Evidence-based Complementary and Alternative Medic Vol.2013 No.-

<P>Obstructive sleep apnea (OSA) is prevalent and associated with several kinds of chronic diseases. There has been evidence that a specific type of Sasang constitution is a risk factor for metabolic and cardiovascular diseases that can be found in patients with OSA, but there are no studies that address the association between the Sasang constitution type (SCT) and OSA. The purpose of this study was to investigate the association between the SCT and OSA. A total of 652 participants were included. All participants were examined for demographic information, medical history, and completed an interviewer-administered questionnaire on life style and sleep-related variables. Biochemical analyses were performed to determine the glucose and lipid profiles. An objective recording of OSA was done with an unattended home PSG using an Embla portable device. The apnea-hypopnea index (AHI) and oxygen desaturation index (ODI) were significantly higher in the Tae-eum (TE) type as compared to the So-eum (SE) and the So-yang (SY) types. Even after adjusting for confounding variables, the TE type still had a 2.34-fold (95% CI, 1.11–4.94; <I>P</I> = 0.0262) increased risk for OSA. This population-based cohort study found that the TE constitutional type is an independent risk factor for the development of OSA.</P>

친수성 제올라이트 분리막을 이용한 알코올/물 혼합액으로부터의 물 분리

이혜련 ( Hyeryeon Lee ),안효성 ( Hyoseong Ahn ),이용택 ( Yongtaek Lee ) 한국화학공학회 2007 화학공학의이론과응용 Vol.10 No.1

해상 태양광을 위한 외부 뇌보호 시스템 사례연구

전혜련(HyeRyeon Jeong),지대영(DaeYeong Ji),이희진(Hee-Jin Lee),이용환(Lee, Yong-Hwan),김성영(SungYoung Kim),최동희(DongHee Choi) 대한전기학회 2021 대한전기학회 학술대회 논문집 Vol.2021 No.10

본 논문에서는 해상태양광을 위한 외부 뇌보호 시스템에 대한 국내외 사례 연구를 진행하였다. 해상태양광은 현재 새롭게 도입되는 개념으로써, 아직 해상태양광에 대한 뇌보호 개념이 국내외에 명확하게 수립되지 않은 실정이다. 따라서 일반적인 육상 해상의 외부 뇌보호 시스템에 대한 분석을 통하여, 해상 태양광에 적용 가능한 외부 뇌보호 시스템을 검토하였다. 이를 기반으로 국외 해상태양광 실증 사례에 대한 뇌보호 시스템 구성 사례를 검토하였다.

Dynein light chain LC8 inhibits osteoclast differentiation and prevents bone loss in mice.

Kim, Hyeryeon,Hyeon, Seungha,Kim, Hojin,Yang, Yoohee,Huh, Ji Young,Park, Doo Ri,Lee, Hyojung,Seo, Dong-Hyun,Kim, Han-Sung,Lee, Soo Young,Jeong, Woojin Williams Wilkins 2013 JOURNAL OF IMMUNOLOGY Vol.190 No.3

<P>NF-κB is one of the key transcription factors activated by receptor activator of NF-κB ligand (RANKL) during osteoclast differentiation. The 8-kDa dynein L chain (LC8) was previously identified as a novel NF-κB regulator. However, its physiological role as an NF-κB inhibitor remains elusive. In this study, we showed the inhibitory role of LC8 in RANKL-induced osteoclastogenesis and signaling pathways and its protective role in osteolytic animal models. LC8 suppressed RANKL-induced osteoclast differentiation, actin ring formation, and osteoclastic bone resorption. LC8 inhibited RANKL-induced phosphorylation and subsequent degradation of IκBα, the expression of c-Fos, and the consequent activation of NFATc1, which is a pivotal determinant of osteoclastogenesis. LC8 also inhibited RANKL-induced activation of JNK and ERK. LC8-transgenic mice exhibited a mild osteopetrotic phenotype. Moreover, LC8 inhibited inflammation-induced bone erosion and protected against ovariectomy-induced bone loss in mice. Thus, our results suggest that LC8 inhibits osteoclast differentiation by regulating NF-κB and MAPK pathways and provide the molecular basis of a new strategy for treating osteoporosis and other bone diseases.</P>

질소 플라즈마 표면처리가 쌀겨 기반 활성탄소의 전기 이중층 커패시터 성능에 미치는 영향

이란은 ( Raneun Lee ),곽철환 ( Cheol Hwan Kwak ),이혜련 ( Hyeryeon Lee ),김석진 ( Seokjin Kim ),이영석 ( Young-seak Lee ) 한국공업화학회 2022 공업화학 Vol.33 No.1

바이오매스 활용을 높이기 위하여, 쌀겨 기반 활성탄소(RHAC)를 제조한 뒤 질소 플라즈마 표면처리를 수행하여 전기이중층 커패시터(EDLC) 성능을 고찰하였다. 질소 플라즈마 표면처리를 통하여, RHAC 표면에 최대 2.17%의 질소가 도입되었으며 특히, 5 min 동안 반응한 샘플의 경우 pyrrolic/pyridine계 N 작용기의 형성이 우세하였다. 또한, 실리카제거에 의해 쌀겨 기반 탄소재에 메조기공이 형성되었고 질소 플라즈마 표면처리에 의해 탄소재 표면 거칠기가 증가하여 미세기공이 많이 형성되는 것을 확인할 수 있었다. 순환전압전류법 측정 실험으로부터, 5 mV/s의 전압 주사 속도에서 질소 플라즈마 처리된 RHAC의 비정전용량은 최대 200 F/g로, 미처리 RHAC (111 F/g)에 비교하여 80.2% 향상된 값을 나타내었다. 이러한 결과는 질소 플라즈마 표면처리로 인해 탄소재 표면에 도입된 pyrrolic/pyridine계 질소 작용기 도입과 탄소재 표면 미세기공 부피 향상으로 인한 시너지 효과인 것으로 판단된다. 본 연구는 폐기 자원을 재활용하고, 플라즈마 표면처리법을 통해 이종원소 도입을 한다는 점에서 환경적으로 긍정적인 영향을 미칠 것으로 사료된다. To increase biomass utilization, rice husk-based activated carbon (RHAC) followed by nitrogen plasma surface treatment was prepared and the electric double-layer capacitor performance was investigated. Through nitrogen plasma surface treatment, up to 2.17% of nitrogen was introduced to the surface of RHAC, and in particular the sample reacted for 5 min with nitrogen plasma showed dominant formation of pyrrolic/pyridine N functional groups. In addition, mesopores were formed on the RHAC material by the removal of silica, and the surface roughness of the carbon material increased by nitrogen plasma surface treatment, resulting in the formation of many micropores. As a result of cyclic voltammetry measurement, at a scan rate of 5 mV/s, the specific capacitance of the RHAC treated with nitrogen plasma increased up to 200 F/g, showing an 80.2% improvement compared to that of using untreated RHAC (111 F/g). This is attributed to the synergetic effect of the introduction of pyrrolic/pyridine-based nitrogen functional groups and the increase of the micropore volume on the surface of the carbon material. This study has a positive effect on the environment in terms of recycling waste resources and using plasma surface treatment.

Vibrio fischeri를 이용한 유해물질 생태독성 평가

이경진(Kyungjin Lee),김종영(Jongyoung Kim),조현정(Hyunjung Jo),송혜련(Hyeryeon Song),천세억(Seuk Cheon),서동민(Dongmin Seo),이문진(Moonjin Lee),이주성(Juseong Lee) 한국해양환경·에너지학회 2022 한국해양환경·에너지학회지 Vol.25 No.4