活性炭에 衣한 3,5-디메틸페놀의 吸着平衡

安旼燁,黃尙勉,鄭在灌 成均館大學校 科學技術硏究所 1998 論文集 Vol.49 No.1

In this study in order to remove 3,5-dimethylphenol from aqueous solutions the granular activated carbon, SLS-100, manufactured by Sam-Chul-Li Company, was used as an adsorbent. The adsorption time to reach equilibrium and the effects of activated carbon size, temperature, and pH were analyzed. Finally adsorption isotherms for various sizes of activated carbon were examined at optimum pH. 1. The adsorption capacity of activated carbon in the size range (-20∼50/60 mesh) of this study was highest at 50/60 mesh size and the equilibriium time for the adsorption of 3,5-dimethylphenol was found 10 days. 2. The maximum adsorption took place at the lowest temperature of 5℃ in the temperature range (5∼50℃) of this investigation. 3. The activated carbon (35/40 mesh) showed its maximum adsorption capacity at pH 7. 4. The Langmuir isotherm as well as the Freundlich isotherm agreed well with the experimental data in the concentration range (1∼80 mg/l) of this experiment, although the Langmuir isotherm showed a little better agreement than Freundlich isotherm.

카트 연료전지용 분리판 개발

황상엽(Hwang, Sang-Youp),하흥용(Ha, Heung-Yong) 한국신재생에너지학회 2006 한국신재생에너지학회 학술대회논문집 Vol.2006 No.11

본 연구에서는 소형 카트용 스택제작에 사용하기 위한 분리판에 관한 연구를 진행하였다. 분리판의 두께가 감소해야 스택의 부피를 줄이고 출력밀도를 높일 수 있기 때문에 분리판 두께 감소를 위한 채널의 깊이 최적화 실험을 진행하였다. 이를 위해 캐소드 채널 깊이에 따른 DMFC 성능의 변화를 관찰하기 위해 캐소드 채널의 깊이를 0.3mm에서부터 1.0mm로 변화시켰다. 채널깊이가 0.5mm일 때 가장 좋은 성능을 보였는데, 원인으로는 단면적 감소에 의한 선속도의 증가와 내부 압력증가를 들 수 있다. 채널깊이 변화에 따른 영향을 분석하기 위해 마노미터를 이용하여 차압을 측정하였고, 임피던스 분석법을 통해 전극의 저항을 측정하였다.

활성탄소 종류에 따른 VOCs 흡/탈착 특성연구

황상엽(Sang Youp Hwang),김석휘(Seokhwi Kim),이기쁨(Gibbum Lee),김지현(Jihyun Kim),박정은(Jungeun Park),홍범의(Bumui Hong) 한국에너지기후변화학회 2017 한국에너지기후변화학회 학술대회 Vol.2017 No.11

Pretreatment with paricalcitol attenuates inflammation in ischemia–reperfusion injury via the up-regulation of cyclooxygenase-2 and prostaglandin E2

Hwang, Hyeon Seok,Yang, Keum Jin,Park, Ki Cheol,Choi, Hyun Soo,Kim, So Hee,Hong, Sung Youp,Jeon, Byeong Hwa,Chang, Yoon Kyung,Park, Cheol Whee,Kim, Suk Young,Lee, Sang Ju,Yang, Chul Woo Oxford University Press 2013 Nephrology, dialysis, transplantation Vol.28 No.5

<P><B>Background</B></P><P>The effect of paricalcitol on renal ischemia–reperfusion injury (IRI) has not been investigated. We examined whether paricalcitol is effective in preventing inflammation in a mouse model of IRI, and evaluated the cyclooxygenase-2 (COX-2) and prostaglandin E2 (PGE2) pathways as a protective mechanism of paricalcitol.</P><P><B>Methods</B></P><P>Paricalcitol (0.3 μg/kg) was administered to male C57BL/6 mice 24 h before IRI. Bilateral kidneys were subjected to 23 min of ischemia, and mice were killed 72 h after IRI. The effects of paricalcitol on renal IRI were evaluated in terms of renal function, tubular necrosis, apoptotic cell death, inflammatory cell infiltration and inflammatory cytokines. The effects of paricalcitol on COX-2, PGE2 and its receptors were investigated.</P><P><B>Results</B></P><P>Paricalcitol pretreatment improved renal function (decreased blood urea nitrogen and serum creatinine levels), tubular necrosis and apoptotic cell death in IRI-mice kidneys. The infiltration of inflammatory cells (T cells and macrophages), and the production of proinflammatory cytokines (RANTES, tumor necrosis factor-α, interleukin-1β and interferon-γ) were reduced in paricalcitol-treated mice with IRI. Paricalcitol up-regulated COX-2 expression, PGE2 synthesis and mRNA expression of receptor subtype EP4 in post-ischemic renal tissue. The cotreatment of a selective COX-2 inhibitor with paricalcitol restored functional injury and tubular necrosis in paricalcitol-treated mice with IRI.</P><P><B>Conclusions</B></P><P>Our study demonstrates that paricalcitol pretreatment prevents renal IRI via the inhibition of renal inflammation, and the up-regulation of COX-2 and PGE2 is one of the protective mechanisms of paricalcitol in renal IRI.</P>

Oncologic outcomes after radical surgery for periampullary cancer in octogenarians

Sung Hyun Kim,Jae Uk Chong,Jin Hong Lim,Moon Jae Chung,Jeong Youp Park,Seung Min Bang,Seung Woo Park,Ho Kyung Hwang,Chang Moo Kang,Woo Jung Lee,Kyung Sik Kim 한국간담췌외과학회 2018 Annals of hepato-biliary-pancreatic surgery Vol.22 No.2

Backgrounds/Aims: Interest in treatments for elderly patients has increased with life expectancy, and various studies have reported on the safety and feasibility of radical surgery in elderly patients with cancer. Here, we investigated oncologic outcomes of periampullary cancer in octogenarians. Methods: We retrospectively reviewed medical records of 68 patients over 80 years of age who were diagnosed with periampullary cancer and were eligible for surgery; we analyzed overall survival (OS) and immediate postoperative complications and mortality. Results: There were no significant differences in mean age, disease type, oncologic features, comorbidities, or nutritional status between the patients who had surgery and those who did not. Five patients (20.0%) had major postoperative complications, but there was no immediate postoperative mortality. Patients who had surgery (n=25) had better OS (29.3 months; 95% confidence interval [CI]: 5.6-53.0) than did those who did not (n=43, OS: 7.6 months; 95% CI: 3.2-12.0 months; p <0.001). Similarly, patients with distal common bile duct cancer who underwent surgery had better OS than those who did not (surgery group: n=13, OS: 29.3 months, 95% CI: 8.9-49.7; non-surgery group: n=15, OS: 5.7 months, 95% CI: 4.2-7.2 months; p=0.002). Conclusions: Radical surgery for octogenarian patients with periampullary cancer is safe, feasible, and expected to result in better survival outcomes, especially for patients with common bile duct cancer.

백서에서 전척추마취시 심박수변이도의 파워 스펙트럼 분석

한성민,이윤경,이소영,권태엽,황규삼 대한마취과학회 2001 Korean Journal of Anesthesiology Vol.40 No.1

Background: Total spinal anesthesia (TSA) anesthetizes cranial nerves as well as peripherial nerves, leading to specific circulatory perturbations related to autonomic imbalance between sympathetic and parasympathetic tone. Heart rate variability (HRV) result from moment-to-moment changes in sym-pathetic and parasympathetic activity in response to many conditions. Using a power spectral analysis of heart rate variability, we evaluated the effect of TSA on the changes in the autonomic nervous system. Methods: Twenty-four Sprague-Dawley rats, during halothane anesthesia, were placed in a stereotaxic head holder. Polyethylene tubing (PE-10) was passed caudally from the cisterma magna, and these rats were anesthetized by a urethane intraperitoneal injection (1.5 g/kg). Succinylcholine was infused in-travenously at 1 mg/kg/min. During mechanical ventilation, ECG signals and mean arterial blood pressure were recorded for 5 min after a period of 10 min of anesthetic stabilization (baseline). Lidocaine (40 mg/kg) was administered intrathecally and then two subsequent 5-min ECG signals and mean arterial blood pressure were recorded (TSA 0-5 min, 5-10 min). A power spectral analysis of the data was computed using a short-time Fourier transform. The spectral Peaks within each measurement were calculated; low frequency area (0.25-0.75 Hz), high frequency area (0.75-3.0 Hz), total frequency area (0.25-3.0 Hz). Results: Mean R-R interval increases progressively during the 5 minutes after TSA but mean blood pressure decreases to the level of blood pressure of TSA within 2 minutes after TSA (p < 0.05). TSA diminished HRV within 2 minutes after a spinal injection of lidocaine (p < 0.05). Conclusions: These results suggest that total spinal anesthesia depresses both sympathetic and parasympathetic tone within 2 minutes. Korean J Anesthesiol 2001; 40: 74 ~81)

Effects of Galla chinensis extracts on UVB-irradiated MMP-1 production in hairless mice.

Sun, Zheng-wang,Hwang, Eunson,Lee, Hyun Ji,Lee, Tae Youp,Song, Hyun Geun,Park, Sang-Yong,Shin, Heon-Sub,Lee, Don-Gil,Yi, Tae Hoo Springer-Verlag Tokyo 2015 Journal of Natural Medicines Vol.69 No.1

<P>Galla chinensis (GAC) is a natural traditional Chinese medicine that has been widely used in folk medicine. Although GAC compounds (mainly gallic acid and methyl gallate) possess strong antiviral, antibacterial, anticancer, and antioxidant activities, there is no report regarding topical or oral administration of GAC compounds on UVB irradiation-induced photoaging in hairless mice (SKH: HR-1). In the present study, we examined cell viability, intracellular reactive oxygen species (ROS), matrix metalloproteinase-1 (MMP-1), and interleukin-6 (IL-6) in skin fibroblasts and keratinocytes induced by UVB in vitro. We also studied skin damage by measuring skin thickness, elasticity, wrinkling and levels of protein MMP-1, elastin, procollagen type I, and transforming growth factor-β1 (TGF-β1) in hairless mouse skin chronically irradiated by UVB in vivo. GAC treatment significantly prevented skin photoaging by reducing the levels of ROS, MMP-1, and IL-6 and promoting production of elastin, procollagen type I, and TGF-β1. According to the results of H&E staining and Masson's trichrome staining, GAC reduced skin thickness and wrinkle formation while it increased skin elasticity. The effects of GAC on UVB-induced skin photoaging may be due to suppressed MMP-1 expression. These findings could be referenced for the development of new agents that target UVB-induced photoaging.</P>

Impact of the oxygen functional group of nitric acid‑treated activated carbon on KOH activation reaction

Ji‑Hyun Kim,Sang Youp Hwang,Jung Eun Park,Gi Bbum Lee,Ho Kim,Seokhwi Kim,Bum Ui Hong 한국탄소학회 2019 Carbon Letters Vol.29 No.3

To prepare activated carbon with a high specific surface area, oxygen functional groups (OFGs) that can serve as useful electron donors during KOH activation were treated with nitric acid and incorporated into activated carbon. OFGs are incorporated differently according to the surface characteristics of starting materials. Up to 22.46% OFGs are incorporated into wood-based activated carbons (WACs), the C=O, COOH contents was 1.90, 17.05%, respectively. Whereas up to 12.82% OFGs are incorporated into coconut shell-based activated carbons, the C=O, COOH contents was 4.12, 6.15%, respectively. The OFGs used for increasing the specific surface area are the carbonyl group, and as the content of the functional group increases, the carbonyl group spreads to the carboxyl group. The specific surface area of activated carbons increased by 10–68% with an increase in the carbonyl group up to 6% (maximum point of carbonyl group). On the other hand, the specific surface area for WACs increased when the carboxyl group was 10% or below, but decreased by 6–15% when it increased to 10% or excess.

Effect of early oral intake on postoperative bowel function in patients undergoing Lower extremities surgery under epidural anesthesia

Cheol Lee,Hwa Sung Lee,Yoon Kang Song,Se Ri O,Seung Jae Byun,Dong Baek Kang,Ji Hyo Hwang,Byoung Ryun Kim,Seo Young Moon,Dong Youp Han 대한마취과학회 2008 Korean Journal of Anesthesiology Vol.55 No.3

차량 주행속도를 반영한 도로 평면선형설계 기법 연구

최재성,김상엽,이점호,황경성,Choi, Jai-Sung,Kim, Sang-Youp,Lee, Jeom-Ho,Hwang, Kyung-Sung 한국도로학회 2008 한국도로학회논문집 Vol.10 No.2

At present engineers use the highway design speed concept to develop the horizontal alignment. This concept has a strength of attaining consistent horizontal alignments because of its use of a single speed value. Yet it shows a critical weakness that when opened the operating speed for the vehicles on the road can be a lot different than the design speed. To resolve this, many countries already develop the horizontal alignment by adopting procedures that weigh vehicle operating speeds, and this research joins them by developing an operating speed based horizontal alignment design. We have collected vehicle speed samples over the nation, selected some speed influential design elements by doing a statistical analysis, provided a set of models for two-lane roads and four lane roads, and showed a stepwise feedback procedure by doing a case study. It is underscored that in the case study the proposed procedure has scaled down the speed inconsistency problem, and we are of opinion that our procedure would coin both investment efficiency and speed consistency in future highway projects. 현재 우리나라에서 도로 평면선형 설계를 위해 도로설계속도 개념을 사용하고 있다. 도로설계속도 개념은 단 한 개 도로 설계속도를 사용하기 때문에 도로 기하구조 수준이 일정해진다는 강점을 갖고 있으나, 도로 건설 후 그 도로를 주행하는 실제 차량 속도가 설계속도와 달리 나타날 수 있다는 약점을 갖고 있기도 하다. 본 연구에서는 이 약점을 보완하기 위해, 이미 여러 나라에서 사용 중인 주행속도 예측모형에 근거한 평면 선형설계기법을 제안한다. 본 연구에서는 이를 위해 우리나라 전역에서 표본을 선택하여 차량 속도조사를 수행했고, 속도에 영향을 미치는 도로설계요소를 통계분석을 통해 선정하여 양방향 2차로와 4차로 일반국도에 대한 차량 주행속도 모형을 제시했으며, 그 모형을 도로 평면선형설계에 적용하는 과정을 제시했다. 한편 새로운 기법에 대한 유효성을 밝히기 위한 실제 사례분석에서 새로운 기법은 기존 기법이 갖고 있는 약점을 해소하는 것으로 밝혀졌다. 향후 우리나라 도로 건설 사업에서 본 연구에서 제안한 평면선형 설계기법을 적용하면 도로 투자 효율성이 높아지고, 더 높은 설계일관성을 확보할 수 있을 것으로 판단한다.