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.

Effects of hydrogen plasma treatment on SnO2:F substrates for amorphous Si thin film solar cells

Min-Seung Choi,Young-Ju Lee,Jung-Dae Kwon,Yongsoo Jeong,Ju-Yun Park,강용철,Pung Keun Song,Dong-Ho Kim 한국물리학회 2013 Current Applied Physics Vol.13 No.8

We investigated the effects of hydrogen plasma treatment on the physical and electrical properties of fluorine-doped tin oxide (FTO) films used for amorphous silicon (a-Si) thin film solar cells. A slight increase in carrier concentration by the hydrogen doping effect was observed for the FTO film exposed to the hydrogen plasma for 5 min. For further exposure to the plasma, the chemical reduction became prominent and resulted in deterioration of the electrical and optical properties of the film. XPS analysis revealed that the chemical reduction of SnO2 to Sn metallic state occurs on the surface region. It was found that the defects formed by hydrogen plasma act as recombination centers at the interface between FTO electrode and p-layer of a-Si solar cells. This phenomenon resulted in the deterioration of the cell performance. The averaged conversion efficiency (6.82%) of the cells on pristine FTO hydrogen substrate was decreased to 5.81% for the cells on FTO treated for 5 min, which is mainly attributed to the decrease in short-circuit current density.

12주간의 태권도 트레이닝이 남자 청소년의 골밀도 및 골 건강관련 호르몬에 미치는 영향

김민형 ( Min Hyung Kim ),정현철 ( Hyun Chul Jung ),강효정 ( Hyo Jung Kang ),김현배 ( Hyun Bae Kim ),송종국 ( Jong Kook Song ) 한국스포츠정책과학원(구 한국스포츠개발원) 2012 체육과학연구 Vol.23 No.4

The purpose of the study was to evaluate the effects of weeks taekwondo training on bone mineral density, and calcemic hormones in male adolescents. 19 male adolescents aged 13-14 years (12 for training group; 7 for control group) were participated in this study. Taekwondo group has been performed 50 minutes a days a week for 12 weeks, as exercise intensity of 60-70 % HRR (heart rate reserver). Control group have only performed the activities included in their physical education classes. Skeletal maturity was assessed by TW3. Bone mineral density at the sites of lumber spine, forearm, femur and whole body were assessed by DXA (Hologic. QDR-4500, USA). Blood samples were drown in the morning after 12-h fast and spun at 3000 rpm for 15 min. 25(OH)D and calcitonin were analyzed by Liaison (Diasorin, USA). Osteocalcin was analyzed by COBAR 5010 (Quantum Packard. USA). Parathyroid hormone was analyzed by E170 (Roche, Germany) and growth hormone was analyzed by Immulite 2000 (DPC, USA). Statical analyses were done with SAS version 9.2. All data were presented in terms of means and standard deviations. Two-wany ANOVA with repeated measure was used for interaction of time x group. Paired t-test was perfomed to change over time in each parameter. Multiple regression analysis was used to find factors that influence dependent variables. A statistically significant level was defined as 95%. The results of this study indicates that bone age for TG (14.9±0.62yr) was significantly advanced compared to chronological age (14.0±0.64yr). but CG had similar bone age (14.1±0.55yr) compared to chronological age (13.9±0.46yr). significant within subjects effects were found for whole body BMD(p<.001), lumbar BMD (p<.001) and forearm BMD (p<.0001). Significant increase could be obtained in TG for whole body BMD, lumbar BMD, and forearm BMD between pre and post-tests However, there was no difference for femoral BMD for both TG and CG. Although no difference was found for serum osteocalcin in CG, significant increase could be observed in TG between pre and post-tests. There was significant within subject effect for PTH in TG (p<.05). Significant interaction effect of group and time was found for GH (p<.0001). serum 25 (OH)D was significantly decreased in both groups throughout the study periods. Bone age, serum calcitonin and lean tissue were predictors for whole body BDM in explaining 51.0%, 64% and 74.0% respective in TG. Bone age was significant predictor for lumbar BMD in explaining 39.0% in TG. In conclusion, 12 weeks taekwondo training has positive effects on bone mineral density and calcemic hormones in male adolescents. Further study is needed to enhance femral BMD as taekwondo training over 12 weeks and higher intensity. 이 연구의 목적은 12주간의 태권도 트레이닝이 남자 청소년의 골밀도와 골 건강관련 호르몬에 미치는 영향을 규명하는 것이었다. 연구대상자는 13~14세 남자 청소년 19명이었으며, 이들을 훈련군(12명)과 통제군(7명)으로 분류하였다. 골격성숙도는 TW3 방법을 적용하여 RUS 점수와 뼈나이를 평가하였고, 골밀도는 DXA를 이용하여 측정하였다. 골 건강관련 호르몬은 osteocalcin(OC), calcitonin(CC), parathyroid hormone(PTH), growth hormone(GH)과 25-hydroxyvitamin D(25(OH)D)를 분석하였다. 그룹 간 태권도 트레이닝 전·후 종속변인의 차이를 규명하기 위해 반복 이원분산분석을 적용하였고, 그룹 내 차이는 대응 t-검정을 이용하여 분석하였다. 골밀도와 뼈나이, 체중, 신장, 골 건강관련 호르몬의 관계를 규명하기 위해 다중회귀분석을 적용하였다. 이 연구 결과 훈련군의 전신 골밀도(p<.001), 요추 골밀도(p<.001), 전완 골밀도(p<.01)는 12주 태권도 트레이닝 전·후 통계적으로 유의하게 증가하였으나 통제군은 유의한 변화가 없었다. 한편 대퇴 골밀도는 훈련군과 통제군 모두 12주 트레이닝 전·후 유의한 변화가 나타나지 않았다. OC는 훈련군(pre: 13.18ng/mL, post: 40.38ng/mL)과 통제군(pre: 13.04ng/mL, post: 40.89ng/mL) 모두 통계적으로 유의하게 증가한 반면, CC는 두 그룹 모두 유의한 변화가 없었다. PTH는 훈련군의 경우 통계적으로 유의하게 감소하였지만(p<.05), 통제군은 유의한 차이를 보이지 않았다. GH는 트레이닝 전·후 훈련군과 통제군에서 유의한 상호작용효과가 나타났으며(p<.05), 훈련군(pre: 0.70ng/mL, post: 4.22ng/mL)에서는 증가한 반면 통제군(pre: 5.40ng/mL, post: 2.04ng/mL)에서는 감소하였다. 25(OH)D는 훈련군과 통제군 모두 통계적으로 유의하게 감소하였다. 골밀도의 예측변인을 분석한 결과 훈련군에서 전신 골밀도의 경우 뼈나이, 제지방조직, 신장이 높은 설명력을 보였고, 요추 골밀도의 경우 뼈나이, 전완 골밀도의 뼈나이, PTH, 생활나이가 유의한 설명력을 나타냈다. 결론적으로 12주간의 태권도 트레이닝은 남자 청소년들의 골밀도와 골 건강관련 호르몬에 긍정적인 영향을 미친 것으로 나타났으며 태권도 트레이닝이 청소년들의 요추 골밀도에 영향을 미치기 위해서는 12주 이상의 장기간의 훈련을 통한 후속연구가 필요할 것으로 사료된다.

암호화된 DB에서 대칭키 기반 검색기법 구현

정민경(Jung, Min-Kyoung),송희정(Song, Hee-Jeong),신승수(Shin, Seung-Soo),한군희(Han Kun-Hee) 한국산학기술학회 2009 한국산학기술학회 학술대회 Vol.- No.-

최근 개인정보유출사건으로 프라이버시에 대한 관심이 급증하면서, 데이터베이스의 내용을 암호화할 필요성이 요구된다. 초기에는 문서 전체의 복호화를 통해서만 검색이 가능하기 때문에 효율성이 떨어져 암호화기법이 거의 사용되지 않았다. 최근에는 복호화 하지 않고 암호화된 데이터로부터 특정 키워드를 포함하는 정보를 효율적으로 검색하고자 하는 연구가 시작되었다. Song의 연구를 시작으로 점차 효율적인 검색 기법이 제안되어졌다. 본 논문에서는 데이터베이스내의 암호화된 데이터를 검색하는 기법에 대한 설계 및 구현하고, 그에 따른 정확도 및 오류율을 분석한다.

청소년의 스마트폰 중독과 우울 및 불안과의 관계

김경은,김필송,민주연,박수경,신서인,이지은,정해인,조호정,최정원,최정인 이화여자대학교 간호과학대학 2013 이화간호학회지 Vol.- No.47

Purpose: The purpose of this study was to investigate the relationships between the degree of smart phone addiction among adolescents and their depression and anxiety levels. Method: In this study, 379 high school students were selected using the convenient sampling method. The instruments used for this study were smart phone addiction measure, the CES-D (Center for Epidemiological Studies-Depression Scale), and the STAI (State-Trait Anxiety Inventory). Data were analyzed using the SPSS 20.0 program with descriptive statistics, t-test, ANOVA with Scheffe test, and Pearson’s correlation coefficient. Result: The mean score for smart phone addiction was 40.45±17.27, depression was 36.56±9.58, state anxiety was 44.00±9.61, and trait anxiety was 45.70±9.75. There were significant differences between the degree of smart phone addiction and the following variables: gender (t=-4.953, p<.001), hours of smart phone use per day (F=12.259, p<.001), types of frequently used features (F=3.485, p=.008), and satisfaction level for smart phone (F=5.18, p<.001). There were statistically significant relationships (p<.001) among degree of smart phone addiction, depression level, and state and trait anxiety levels. Conclusion: The results of this study suggested that there was a significant relationship between smart phone addiction and mental health, specifically, depression and anxiety among adolescents. Further research is needed to develop nursing strategies to provide care for adolescents who frequently utilize smart phones.

열처리가 Al-Mg 코팅 강판의 내식성에 미치는 영향

정재훈(Jae-Hun Jung),양지훈(Ji-Hoon Yang),송민아(Min-A Song),김성환(Sung-Hwan Kim),정재인(Jae-In Jeong),이명훈(Myeong-Hoon Lee) 한국표면공학회 2014 한국표면공학회지 Vol.47 No.4

Double layer films which consisted of aluminum(Al) and magnesium(Mg) have been prepared by e-beam deposition. The structure, alloy phase, and corrosion resistance of the prepared films were investigated before and after heat treatment. The first (bottom) layer fixed with Al, and the thickness ratio between Al and Mg layers has been changed from 1 : 1 to 5 : 1, respectively. Total thickness of Al-Mg film was fixed at 3 μm. The cold-rolled steel sheet was used as a substrate. Heat treatment was fulfilled in an nitrogen atmosphere at the temperature of 400℃ for 2, 3 and 10 min. Surface morphology of as-deposited Al-Mg film having Mg top layer showed plate-like structure. The morphology was not changed even after heat treatment. However, cross-sectional morphology of Al-Mg films was drastically changed after heat treatment, especially for the samples heat treated for 10 min. The morphology of as-deposited films showed columnar structure, while featureless structure of the films appeared after heat treatment. The x-ray diffraction data for as-deposited Al-Mg films showed only pure Al and Mg peaks. However, Al-Mg alloy peaks such as Al3Mg2 and Al12Mg17 appeared after heat treatment of the films. It is believed that the formation of Al-Mg alloy phase affected the structure change of Al-Mg film. It was found that the corrosion resistance of Al-Mg film was increased after heat treatment.

위암 환자의 복강내 투여를 위한 Activated Charcoal-Alginate Bead 제형으로부터 Mitomycin C의 용출 거동

이진호,최선웅,서중기,김동민,정경수,오정연,김진향,노승무,민병무,김용백,김창식,박근성,강대영,송규상,양준묵,조준식,정현용,김학용,인현빈 충남대학교 의과대학 지역사회의학연구소 1998 충남의대잡지 Vol.25 No.1

Locoregional recurrence is the most common type of recurrence in surgical operation of gastric adenocarcinoma, and peritoneal dissemination is one of the most difficult problems in advanced gastric adenocarcinoma treatment. Because the peritoneal cavity is the most common site of the first recurrence after gastric cancer resection, intraperitoneal chemotherapy seems a logical choice for cancer chemotherapy. In this study, Mitomycin C (MMC)-activated charcoal (CH)-alginate (ALG) beads were prepared by the mixtures of CH particles adsorbed with MMC as an anti-cancer drug and aqueous alginate solution. The alginate is recognized as biodegradable, nontoxic, and biocompatible. The release of MMC from the beads in 0.1 M Tris buffer was stable and continuous until about 1 week. The MMC-CH-ALG beads can be applied in the peritoneal cavity for intraperitoneal chemotherapy since they provide a good adhesiveness on the tissue and controlled release pattern of the drugs.

인체혈장 중 에탐부톨의 HPLC 분석법의 검증 및 단일용량 투여에 의한 약물동태 연구

곽혜선,박경호,최준식,송진아,성민경,장정옥,이화정 한국약제학회 2005 Journal of Pharmaceutical Investigation Vol.35 No.2

An HPLC method was employed for the determination of ethambutol in human plasma. After addition of internal standard (IS, octylamine, 2 μg/mL) and alkalinization of the plasma with 5 M sodium hydroxide, the drug and IS were extracted into the mixture of chloroform and diethyl ether (40:60, v/v). Following a 15-min vortex-mixing and a 10-min centrifugation, the organic phase was spiked with 100 pL of phenylethylisocyanate (2000 μg/mL) for chemical derivatization, mixed for 5 min and evaporated to dryness under a stream of nitrogen. The residue was reconstituted with 100 μL of mobile phase and 20 pL was injected into Cl8 column with a mobile phase consisting of methanol:water (70:30, v/v). The samples were detected utilizing an ultraviolet detector at 200 nm. The method was specific and validated with a limit of 0.15 μg/mL. Infra- and inter-day precision and accuracy were acceptable for all quality control samples including the lower limit of quantification. The applicability of this method was demonstrated by analysis of human plasma after oral administration of a single 1200-mg dose to 20 healthy subjects. From the plasma ethambutol concentration vs. time curves, the mean AUC was 9.61 ± 1.64 μg hr/mL. and Cmax of 2.68 μg/mL reached 2.73 hr after administration. The mean biological half-life of ethambutol was 3.46 ± 1.21 hr. Based on the results, this simple and validated assay could readily be used in any pharmacokinetic studies using humans.

팽이버섯 재배 현장에서 Listeria monocytogenes의 성장을 억제하기 위한 살균 처리 기술 개발

박경민,이수빈,정도영,최송이,황인준,김세리,Kyung Min Park,Su-Bin Lee,Do-Young Jung,Song-Yi Choi,Injun Hwang,Se-Ri Kim 한국식품위생안전성학회 2023 한국식품위생안전성학회지 Vol.38 No.6

본 연구는 팽이버섯 생산현장에서 사용하는 권지 접착포에서 팽이버섯으로 Listeria monocytogenes 교차오염을 예방하기 위하여 화학적 살균제에 의한 L. monocytogenes 저감 효과를 확인하였다. 과산화초산, 미산성전해수, 이산화염소수, 차아염소산나트륨을 10분간 처리했을 때 권지표면에 부착된 L. monocytogenes를 최대 99.99% 이상 저감화시켰고, 이들 4종의 살균소독제는 팽이버섯 유기물 존재 여부에 관계없이 높은 살균능을 보이므로 권지의 세척소독에 활용가능성이 있음을 확인하였다. 특히 과산화초산은 권지 접착포 거친면과 부드러운면 모두에서 L. monocytogenes를 99.999% 이상 감소시킬 수 있으므로 팽이버섯 권지 세척시 30mg/L 이상의 과산화초산에 30분 이상 침지한 후 사용하면 권지에 오염된 L. monocytogenes의 교차오염을 예방할 수 있을것으로 사료된다. The consumption of enoki mushrooms has been associated with cases of listeriosis produced by Listeria monocytogenes, highlighting the significance of sanitizing food-contact surface, such as the velcro used in welding processing of enoki mushrooms, to ensure microbial safety. We investigated the inhibitory activity of nine chemical disinfectants at regular concentrations against L. monocytogenes isolated from a mushroom farm environment. The bacterial suspension was prepared in phosphate buffered saline and mushroom extract broth and inoculated onto the velcro surface. After inoculation, most disinfectants reduced the initial 8 log CFU/coupon concentration by less than 2 log CFU/coupon during a 5-min treatment. Slightly acidic hypochlorous water showed a reduction of approximately 4 log CFU/coupon when tested for more than 30 min at the maximum allowable concentration of 200 mg/L. Sodium hypochlorite solution showed a reduction of approximately 5 log CFU/coupon when used at 100 mg/L for 60 min. Peracetic acid, at the maximum allowable concentration of 300 mg/L, showed the most effective reduction of 5 log CFU/coupon or more when the surface was treated with 37.5 mg/L for 30 min. These results indicate that peracetic acid can be used as the disinfectant strategy to control cross-contamination of L. monocytogenes on the velcro surface of plastic wrappers used in the welding processing of enoki mushrooms.

판막 질환에서의 심근 섬유화 : 심근 조직을 이용한 형태학적 연구 및 혈청 생화학적 지표의 분석

강수진,박덕우,송재관,박경민,송종민,강덕현,한기훈,송현,이재원,주석중,송명근,김정선 대한순환기학회 2004 Korean Circulation Journal Vol.34 No.2