Impact of Irradiation Time on the Hydrolysis of Waste Activated Sludge by the Dielectric Heating of Microwave

Tae Joo Park,Im Gyu Byun,Jae Ho Lee,Ji Sung Lim,Jeong Min Lee 대한환경공학회 2014 Environmental Engineering Research Vol.19 No.1

The effects of initial solid concentration and microwave irradiation (MWI) time on the hydrolysis of waste activated sludge (WAS)were investigated. MWI time strongly influenced WAS hydrolysis for all initial solid concentrations of 8.20, 31.51, and 52.88 g VSS/L. For all WAS, the volatile suspended solids (VSS) solubilization degree ranged from 35.6% to 38.4% during a total MWI time of 10 min. Solublechemical oxygen demand (SCOD) concentration increased at a rate proportional to the decrease of VSS during the MWI. However, the clearly different VSS solubilization patterns that were observed during the MWI were explained by the 2-step hydrolysis of WAS, consisting of the initial disintegration of the easily degradable part of the sludge, followed by the subsequent disintegration of the hardlydegradable part of the sludge. WAS hydrolysis rates for 3 to 6 min of MWI were significantly lower than those for less than 3 min, or more than 6 min. From these results, 3 min MWI time and WAS of 31.51 g VSS/L (centrifugal thickener WAS) showed the most efficienthydrolysis of WAS at 36.0%. The profiles of total nitrogen (T-N) concentrations corresponded well to the SCOD increases in terms of the empirical formula of bacterial cell mass (C5H7O₂N). The negligible T-N increase and pH decrease during WAS hydrolysis by MWI will allowthe application of this process to subsequent biological processes, such as anaerobic digestion.

건강한 청년의 단시간 공해노출과 일회성 운동이 폐기능과 생리반응에 미치는 영향

김민주(Min-Joo Kim),이대택(Dae-Taek Lee),송국섭(Gook-Sup Song),방승기(Seung-Ki Pang) 한국생활환경학회 2015 한국생활환경학회지 Vol.22 No.1

This study examined whether an acute exercise during a short-term exposure to a polluted environment affected pulmonary function and physiological responses in healthy young adults. Thirteen men (mean = 22.4 yrs) were randomly exposed to a polluted air (PA) or to clean air (CA) in a chamber. During the exposure, they rested for 30 min followed by a bench stepping exercise (40 cm height, 120 bpm) for 10 min. And they recovered from the exercise for 15 min in the chamber. The pulmonary function, heart rate, blood lactate, and blood pressure were measured during the exposure. At the end of 30 min resting, peak expiratory flow rate (PEFR) was higher in PA than CA. Immediately after the exercise, forced expiratory volume at 1 sec (FEV1) was higher in PA than CA. At 15th min of recovery, forced vital capacity, FEV1, and PEFR were significantly higher in PA than CA. No differences in cardiovascular and blood lactate responses were noticed. The results suggest that an acute intensive physical work out with breathing of volatile organic compounds induced changes of pulmonary function but not physiological adjustments.

간헐식 흐름방식을 활용한 수직 · 수평 습지의 정화효율 평가

주광진(Kwang Jin Joo),이동민(Dong Min Lee),김기중(Ki Jung Kim),조용철(Yong Chul Cho),장광현(Gwang Hyeon Jang),최이송(I Song Choi),오종민(Jong Min Oh) 응용생태공학회 2017 Ecology and resilient infrastructure Vol.4 No.3

본 연구에서는 부영양화의 원인이 되는 질소와 인의 제거 효율을 향상시킬 목적으로 광물질을 활용한 여재를 이용하여 호기, 혐기의 흐름조건을 만들어주기 위한 수직·수평 흐름 인공습지를 고안하여 아크릴 반응조로 제작한 후 성능평가를 진행하였다. 수직·수평 흐름형 인공습지의 경우 호기 및 혐기조건을 평가하기 위해서 반응조 내 용존산소(DO) 농도를 측정해본 결과 호기상태에서는 2.7 ㎎/L, 혐기상태에서는 N.D로 확인되어 목적에 부합된 결과가 확인되었다. 실험결과에서는 SS 저감효과가 140 min, 80 min, 60 min의 운전시간에서 각각 94%, 91%, 61%의 효율을 보였고, T-P의 경우 각각의 운전시간에 따라 84%, 71%, 63%의 저감효율을 보였다. 또한 T-N의 경우 각각의 운전시간에 따라 63%, 49%, 42%의 저감효율을 보여 기존의 습지가 12~24 hr 체류시간을 가지는 것에 비하여 짧은 운전시간에도 높은 처리효율을 보이는 것으로 확인되었다. 본 연구에서는 수직·수평 흐름 방식을 복합 적용하여 기존 인공습지의 단점을 보완하기 위해 기술개발을 진행한 것으로 어떠한 기능적 효과를 갖는지 확인하였고, 향후 이에 대한 현장적용을 위한 운영 및 관리적 차원의 메커니즘 연구가 추가로 진행 될 필요가 있다. Nitrogen and phosphorus are key factors in causing eutrophication of water body. In this study, ceramics media was selected to increase the removal efficiency of nitrogen and phosphorus. We designed vertical, horizontal flow constructed wetlands to create aerobic and anaerobic flow conditions by using the media, then proceeded to performance evaluations after acrylic reactors were produced. In the case of vertical and horizontal flow constructed wetlands, we measured oxygen concentrations to evaluate aerobic and anaerobic conditions. we got the result of 2.7 ㎎/L in the aerobic condition, N.D in the anaerobic condition respectively, which suited our purpose. The result of the combined vertical and horizontal flow condition showed that the removal efficiency of SS was 94%, 91%, 61% at 140 min, 80 min, 60 min of running times, respectively, and the removal efficiency of T-P was 84%, 71%, 63% during each running time. In case of T-N, the removal efficiency was 63%, 49%, 42% during each running time. We found that the reactor exerted better removal efficiency when in the short time compared to 12 - 24 hr residence time of existing wetlands. In this study, we conducted experiments to explore functional effects after applying combined vertical and horizontal flow methods in the field. Further study will be carried out to identify its mechanism and administrative perspective.

대장내시경검사의 전처치로서 항콜린제 사용에 관한 연구 : 전향적, 이중맹검법으로

박경남,한동수,이민호,최호순,박준용,손주현,이오영,함준수,전용철,송승찬,기춘석,윤병철,이종희 대한소화기내시경학회 1997 Clinical Endoscopy Vol.17 No.3

Background: Use of antispasmodic medication prior to colonoscopy is controversial but someone believes antispasmodic may improve visualization of colonic mucosa and ease colonoscope insertion. So, we designed a study to assess the effect of premedication with the antispasmodic, hyoscine-N-butyl bromide(Buscopan') on the performance of colonoscopy. Methods: This study was prospective, double blinded, randomized, controlled study, One hundred three consecutive patients were randomized to receive intravenous buscopan lml(n=52) or placebo(n=51) combined with our standard initial medication(me- peridine 50 mg and midazolam 2 mg). Insertion of colonoscopy was timed, and 100 mm visual analogue scales (VAS) were used for asscssing difficulty of procedure, colonic motility, frequency of positional change, frequency of external compression, difficulty of assistance and degree of discomfort experienced by the patients. Results: There were no significant differences of intubation time between buscopan group(mean time, 7.23 min., range 2~15) and placebo group(7.07 min., range 3-25), (p=0.83) and withdrawal time between buscopan group (6.46 min., range 2-22) and placebo group(6.76 min., range 2 25), (p=0.69). Also, there was no significant differences in intubation time between males and females(buscopan; males 7.00 min., females 7.60 min., p=0.34, placebo; males 7.0~5 min., females 7.08 min., p 0.44). The VAS scores checked by endoscopist(p=0.29), assistant(p=0.32) and patient (p=0.15) were not significantly different in both groups. There were no significant differences in intubation time, VAS scores nf endoscopist, assistant, and patients. Conclusion: Premedication with intravenous bu.opan has no advantage on colonoscopy procedure. Use of antispasmodic medication prior to colonoscopy was not considered as recommendable agent.

GO-41 : Single port laparoscopic trans-umbilical extra-peritoneal para-aortic lympadenectomy

( Min Jong Song ),( Joo Hee Yoon ) 대한산부인과학회 2012 대한산부인과학회 학술대회 Vol.99 No.-

A 59 year old woman affected by squamous carcinoma of the cervix, FIGO stage IIB, with enlarged external iliac and common iliac lymph nodes at a CT scan with, was scheduled to extra peritoneal paraaortic lymphadenectomy to rule out para-aortic lymph nodes metastasis and decide treatment modality. A 2 cm vertical incision was made at the midline of umbilicus. Open access of umbilicus wall was performed and the surgeon`s index finger and 10mm indicator were inserted into retroperitoneal space to bluntly develop it. After the introduction of Glove port disposable single port device, 12 mm Hg pressure of carbon dioxide gas was insufflated into retroperitoneal space. A 5 mm, 30° laparoscope was inserted into the right lower port, dissector into the left upper port and harmonic scalpel into the left lower poert. After identification retroperitoneal structure such as the psoasmuscle, iliac vessels, and ureter, development of the retroperitoneal space was continued till the identification of the inferior mesenteric artery. The lymphadenectomy specifically targeted the left-sided infra-mesenteric para-aortic spaces to exclude para-aortic lymph node metastasis. The operation was performed successfully without complication and any placement of retroperitoneal drain. Operative time was 130 min. 16 lymph nodes were removed and no metastasis was detected. Ambulation and dietary intake was started in day 0. Patient was discharged on day two. This report suggests that single port laparoscopic trans-umbilical extra-peritoneal para-aortic lymphadenectomy for surgical staging of locally advanced cervical cancer is feasible. Furthermore this procedure may reduce the chance of port site hernia and allow the patients to be taken following treatment.

Effect of Al and Mg Contents on Wettability and Reactivity of Molten Zn–Al–Mg Alloys on Steel Sheets Covered with MnO and SiO2 Layers

Joo‑Youl Huh,Min‑Je Hwang,Seung‑Woo Shim,Tae‑Chul Kim,Jong‑Sang Kim 대한금속·재료학회 2018 METALS AND MATERIALS International Vol.24 No.6

The reactive wetting behaviors of molten Zn–Al–Mg alloys on MnO- and amorphous (a-) SiO2-covered steel sheets wereinvestigated by the sessile drop method, as a function of the Al and Mg contents in the alloys. The sessile drop tests werecarried out at 460 °C and the variation in the contact angles (θc) of alloys containing 0.2–2.5 wt% Al and 0–3.0 wt% Mg wasmonitored for 20 s. For all the alloys, the MnO-covered steel substrate exhibited reactive wetting whereas the a-SiO2-coveredsteel exhibited nonreactive, nonwetting (θc > 90°) behavior. The MnO layer was rapidly removed by Al and Mg contained inthe alloys. The wetting of the MnO-covered steel sheet significantly improved upon increasing the Mg content but decreasedupon increasing the Al content, indicating that the surface tension of the alloy droplet is the main factor controlling its wettability. Although the reactions of Al and Mg in molten alloys with the a-SiO2 layer were found to be sluggish, the wettabilityof Zn–Al–Mg alloys on the a-SiO2 layer improved upon increasing the Al and Mg contents. These results suggest that thewetting of advanced high-strength steel sheets, the surface oxide layer of which consists of a mixture of MnO and SiO2,withZn–Al–Mg alloys could be most effectively improved by increasing the Mg content of the alloys.

Toxicoproteomic analysis of deltamethrin exposure in neuroblastoma cell lines

Min‑Joo Kang,Mi‑Young Lee 대한독성 유전단백체 학회 2020 Molecular & cellular toxicology Vol.16 No.1

Background Deltamethrin, a type II pyrethroid insecticide, has been widely used due to its high efficacy against insects and low toxicity to mammals. However, recently, potential adverse health effects during deltamethrin exposure have been reported. Methods A proteomic analysis using two-dimensional electrophoresis with mass spectrometry was performed, and the proteomic data were validated by western blotting. Antioxidant enzyme activity was also measured by spectrophotometric analysis. Results The 13 differentially expressed proteins, of which 8 were up-regulated and 5 down-regulated, are involved in a variety of cellular functions including protein folding, cytoskeleton regulation, and splicing process. The activities of antioxidant enzymes and acetylcholinesterase were also altered by deltamethrin exposure. Conclusion Differential protein expression caused by deltamethrin exposure in neuroblastoma cell lines could allow us to develop biomarkers for deltamethrin toxicity, and pursue future studies to assess the molecular mechanisms of deltamethrin toxicity.

Min-Hash를 이용한 효율적인 대용량 그래프 클러스터링 기법

이석주(Seok-Joo Lee),민준기(Jun-Ki Min) 한국정보과학회 2016 정보과학회논문지 Vol.43 No.3

그래프 클러스터링은 서로 유사한 특성을 갖는 정점들을 동일한 클러스터로 묶는 기법으로 그래프 데이터를 분석하고 그 특성을 파악하는데 폭넓게 사용된다. 최근 소셜 네트워크 서비스와 월드 와이드 웹, 텔레폰 네트워크 등의 다양한 응용분야에서 크기가 큰 대용량 그래프 데이터가 생성되고 있다. 이에 따라서 대용량 그래프 데이터를 효율적으로 처리하는 클러스터링 기법의 중요성이 증가하고 있다. 본 논문에서는 대용량 그래프 데이터의 클러스터들을 효율적으로 생성하는 클러스터링 알고리즘을 제안한다. 우리의 제안 기법은 그래프 내의 클러스터들 간의 유사도를 Min-Hash를 이용하여 효과적으로 추정하고 계산된 유사도에 따라서 클러스터들을 생성한다. 실세계 데이터를 이용한 실험에서 우리는 본 논문에서 제안하는 기법과 기존 그래프 클러스터링 기법들과 비교하여 제안기법의 효율성을 보였다. Graph clustering is widely used to analyze a graph and identify the properties of a graph by generating clusters consisting of similar vertices. Recently, large graph data is generated in diverse applications such as Social Network Services (SNS), the World Wide Web (WWW), and telephone networks. Therefore, the importance of graph clustering algorithms that process large graph data efficiently becomes increased. In this paper, we propose an effective clustering algorithm which generates clusters for large graph data efficiently. Our proposed algorithm effectively estimates similarities between clusters in graph data using Min-Hash and constructs clusters according to the computed similarities. In our experiment with real-world data sets, we demonstrate the efficiency of our proposed algorithm by comparing with existing algorithms.

Development of a Chest‑Belt‑Type Biosignal‑Monitoring Wearable Platform System

Joo‑Hyeon Lee,Hyun‑Seung Cho,Jin‑Hee Yang,Sang‑Min Kim,Jeong‑Whan Lee,Hwi‑Kuen Kwak,Je‑Wook Chae 대한전기학회 2020 Journal of Electrical Engineering & Technology Vol.15 No.4

The purpose of this study was to develop a wearable platform system that can detect and acquire a soldier’s biosignals (i.e., heart activity signal, respiration rate, etc.) in a nonrestrained, unconscious manner. These detected biosignals are transmitted to a processing device to analyze and monitor the soldier’s physical status. To achieve this, textile-based heart activity electrodes and a strain gauge sensor for the respiration signal measurement were developed, and their performances in detecting each signal were verifed. These sensors were embedded in a chest belt to design a wearable platform that can simultaneously measure heart activity and respiration signals. The sensor part of the chest belt has a dual layer structure to detect high-quality signals. Stretch fabric was used on the outer layer and a respiration sensor was attached to the belt. On the inside layer, a non-stretch fabric was used as the base fabric and a heart activity-sensing electrode, that is capable of taking measurements using a modifed lead-II heart activity signal induction method, was embroidered onto the fabric. Subjects were asked to wear the chest belt, and a biosignal processor module was attached to verify the system’s performance while simultaneously acquiring the heart activity and respiration signals. More specifcally, it was confrmed that the two signals were detected in a stable. It is expected that the biosignal-monitoring wearable platform system developed in this study will be able to efectively analyze and monitor soldiers’ biosignals.

독도(경상북도 울릉군)의 거미상

김주필(Joo Pil Kim),최한석(Han Seak Choi),지승환(Seung Hwan Ji),김대희(Dae Hee Kim),변진관(Jean Koan Byun),이형민(Hyung Min Lee),조형진(Hyung Jeen Jo),이형진(Hyung Jeen Lee),이태후(Tae Hoo Lee),한정혁(Jung Huk Han),조윤규(Yoon Kyu Jo 한국거미연구소 2018 한국거미 Vol.34 No.2

2018년 7월 27일부터 독도 지역을 한국거미연구회 회원 17명(김주필, 최한석, 김대희, 지승환, 이형민, 변진관, 조형진, 이형진, 이태후, 한정혁, 조윤규, 조원규, 이현동, 이윤정, 조용하, 윤혜원, 이용화)이 채집한 결과 7과 9속 12종이 채집되어 이에 보고 발표하는 바이다. 2018 July 27th, Koran Arachnological Study members investigated the Spiders in the whole area Dok Island (Gyeongsangbuk-do, Ulleung-gun), and reported 7 Families, 9 Genus 12 Species of spiders. The collected spiders are placed (stored) in the Joo-Pil Spider museum.