[논문]Operational Characteristics of CO2 Laser Adopted by Superposing-Discharge

Hee-Je Kim,Hyun-Ju Chung,Byoung-Dae Min,Jong-Han Joung,Sung- lun Park 釜山大學校生産技術硏究所 2003 生産技術硏究所論文集 Vol.62 No.-

오늘날 현저한 CO2 레이저의 응용 추세에 발맞추어 보다 다양한 형태의 출력 제어 기술이 대두되고 있다. 본연구에서는multi-Pulse Superposing-Discharge 기술을 이용하여 다양한형태의 CO2 레이저의 펄스를 성형 하였다. 펄스 성형을 위한 방법으로 PIC one-chip microprocessor를 이용하여 삼중 PFN 모률의 SCR을 각각 고유의 지연시간을 가지도록 제어하였다. 실험에 사용된 삼중 PFN 모률의 전원 회로는 각각 캐패시터 인덕터,SCR,고압 펄스 트랜스 그리고 고압 트랜스 2차측에 브릿지 정류기로 구성 하였다. 고압 펼스 트랜스의 1차측을 제어하므로서 PFN 모률의 동작을 저 전압에서 수행 할 수 있다. 트랜스의 2차측에 연결된 전파 정류기는 펄스 에너지를 부하에 지속적으로 전달한다. 본 연구에서는 삼중 PFN 모률의 각각의 SCR을 다른 시간 가격을 두고 트리거 하므로서 다양한 Long pulse shaping을 실현하였다. 또한 약 250-1000μs 의 주기를 가지는 다양한 펄스형 레이저 빔을 얻었다.

Evaluation of High Power Light Emitting Diodes (HPLEDs) as Potential Attractants for Adult Spodoptera exigua (Hübner)

Min-Seok Oh,Sang-Guei Lee,Ju-Hyun Jeon,Hoi-Seon Lee 한국응용곤충학회 2010 한국응용곤충학회 학술대회논문집 Vol.2010 No.10

To response evaluation of high power light emitting diodes (HPLEDs) as potential attractants to the Spodoptera exigua adults, we investigated the attractiveness of specific wavelength, illuminance intensity and light-exposure time, and compared them to the fluorescent. The all light treatments with the 40 lux intensity attracted the significantly highest number of S. exigua. The optimal light-exposure time exhibited the highest attraction rate at the 60 min. When the attraction and repellent rate in the optimal conditions to the S. exigua was surveyed, the white HPLED exhibited the highest attraction rate (91.1%), whereas the red HPLED exhibited the most repellent rate (33.3%). When evatuated of illuminance efficiency with fluorescent as control, white and red HPLED were found to be 9.14 and 10.34 times more efficient than fluorescent. These data clearly show that both the 40 lux intensity and the 60 min light-exposure time by using the white HPLED was the most suitable for attraction of the S. exigua.

저농도 이산화탄소 포집용 흡착제 개발 및 최적조건에 관한 연구

이주열 ( Ju Yeol Lee ),박덕신 ( Duck Shin Park ),조영민 ( Young Min Cho ),권순박 ( Soon Park Kwon ),황윤호 ( Yoon Ho Hwang ),송형진 ( Hyung Jin Song ),이상봉 ( Sang Bong Lee ) 한국유화학회 2012 한국응용과학기술학회지 Vol.29 No.1

본 논문은 다양한 시설내에 적은 농도의 CO2 제거를 위한 선택적 CO2 흡수능력을 향상시킨 흡착제의 효율평가에 관한 것이다. 직경 4mm의 구형 흡착제는 시판용 제올라이트에 첨가제, 물, 바인더, LiOH를 섞어 제조하였다. 칼럼테스트에서 400분 이내에 90% 이상의 CO2흡착효율을 나타내었고, 흡착필터모듈 흡착능력을 평가하기 위해 회분식과 연속식타입의 챔버테스트가 시행되었다. 회분식테스트에서 30분 이내에 약 92%의 CO2가 제거되는 것을 확인하였다. 연속식테스트에서 30분 이내 70%의 CO2가 제거효율을 보였으며, 2,500ppm 이상의 CO2가 제거되는 것을 확인하였다. 재현성테스트를 수차례 수행한 결과 15일동안 1,000ppm 이상의 CO2가 연속적으로 제거됨을 보였다. TGA 분석법을 이용한 흡착량 분석에서 흡착제 g당 5.0mmol의 CO2를 흡착하는 것으로 나타났다. 본 연구에서 개발된 흡착제는 상온에서 저농도 CO2 실내환경에 적용가능한 것으로 판단된다. In this study, CO2 adsorbent was developed for removing low concentration of CO2 in multiple-use facilities. The efficiency of the adsorbent which was improved selective CO2 adsorption capabilities was evaluated. The pellet type adsorbent was modified from a commercial zeolite with mixing LiOH, binder, additives, and H2O. Column tests showed over 90 % of CO2 was adsorbed within 400min. Chamber tests including batch and continuous types were performed for evaluating the adsorbent module. By batch tests, it was evaluated that about 92 % of CO2 was removed within 30 min. By continuous tests, 70% of CO2 was removed within 30 min. It was analyzed that over 2,500 ppm of CO2 was continuously removed as shown chamber tests. The reproducibility tests repeatedly performed for 15 days shows that over 1,000 ppm of CO2 was continuously removed. Adsorption capacity of the developed adsorbent was 5.0mmol CO2/g adsorbent which was analyzed by TGA. It was estimated that the modified adsorbent was applicable to low CO2 concentration and low temperature of indoor environment.

A well-ordered flower-like gold nanostructure for integrated sensors via surface-enhanced Raman scattering

Kim, Ju-Hyun,Kang, Taejoon,Yoo, Seung Min,Lee, Sang Yup,Kim, Bongsoo,Choi, Yang-Kyu IOP Pub 2009 Nanotechnology Vol.20 No.23

<P>A controllable flower-like Au nanostructure array for surface-enhanced Raman scattering (SERS) was fabricated using the combined technique of the top-down approach of conventional photolithography and the bottom-up approach of electrodeposition. Au nanostructures with a mean roughness ranging from 5.1 to 49.6 nm were obtained by adjusting electrodeposition time from 2 to 60 min. The rougher Au nanostructure provides higher SERS enhancement, while the highest SERS intensity obtained with the Au nanostructure is 29 times stronger than the lowest intensity. The SERS spectra of brilliant cresyl blue (BCB), benzenethiol (BT), adenine and DNA were observed from the Au nanostructure. </P>

Analysis of Lignans in Acanthopanax sessiliflorus Fruits and Their Fermented Wine by HPLC

Hye-Min Kim,Ju-Sun Kim,Seon-Haeng Cho,Sam-Sik Kang,Dae-Sung Cheoi,Sang-Hyun Lee 한국약용작물학회 2006 한국약용작물학회지 Vol.14 No.5

High performance liquid chromatography (HPLC) was used for the determination of lignans, eleutherosides B and E, in Acanthopanax sessiliflorus fruits and their fermented wine. The lignans were quantified by a reversed-phase system using a gradient of H2O and acetonitrile as a mobile phase within 20 min. The analysis was successfully carried out within 20 min. The contents of eleutherosides Band E as main active principles of Acanthopanax species were measured in A. sessiliflorus fruits (1.15 and 8.49 μg/mg, respectively), their fermented wine (0.45 and 1.33 μg/mg, respectively) and wine residues (no detection).

친환경 세척제의 처리 방법을 달리하여 착즙한 당근 주스의 미생물 안전성 및 품질

임상욱(Sang-Wook Lim),최다정(Da-Jeong Choe),강민정(Min-Jung Kang),김종현(Jong-Hyun Kim),김묘정(Myo-Jeong Kim),김민주(Min-Ju Kim) 한국식품영양과학회 2017 한국식품영양과학회지 Vol.46 No.10

본 연구에서는 당근의 세척에 사용되는 친환경 세척제의 초기 미생물 제어 효과를 향상시키기 위해 탄산수소나트륨과 구연산의 단독 및 병합 처리 조건을 설정하였으며 저장 중 당근 주스의 미생물 수 및 품질 특성 변화를 분석하였다. 친환경 세척제의 단독 처리 방법으로는 0.5, 1, 2% 탄산나트륨수와 0.2, 0.5, 1% 구연산수를 적용하였고, 살균 효과를 비교하기 위해 무처리구, 수돗물 처리구, 50 ppm 차아염소산나트륨 처리구를 사용하였다. 당근의 세척을 위한 병합처리 방법으로는 단독 처리에서 우수한 살균 효과를 나타낸 1% 탄산수소나트륨수와 1% 구연산수를 이용하였고, 1% 탄산수소나트륨수 처리 후 1% 구연산수로 처리하는 단계적 병합 처리구가 가장 우수한 살균 효과를 나타내었다. 1% 탄산수소나트륨수와 1% 구연산수의 단계적 병합 처리구는 무처리구에 비해 일반 세균수 1.87 log CFU/mL, 대장균군 1.56 log CFU/mL를 감소시켰고, 50 ppm 차아염소산수에 비해서도 일반 세균수 1.07 log CFU/mL, 대장균군 0.22 log CFU/mL의 미생물 감균효과를 나타냈다. 1% 탄산수소나트륨수 처리 후 1% 구연산수의 단계적 병합 처리구를 4°C에서 7일 동안 저장한 결과 수돗물, 50 ppm 차아염소산수나 혼합 병합 처리구, 1% 구연산수 처리 후 1% 탄산수소나트륨 처리구에 비해 미생물 제어 효과가 확실하게 나타났지만, pH, 당도, 산도, 색도에는 유의적인 차이가 나타나지 않았다. 본 연구 결과 1% 탄산수소나트륨과 1% 구연산의 단계적 병합 처리는 당근 세척 시 초기 미생물 제어와 품질 유지에 있어 효과적인 살균처리 방법으로 비가열 당근 주스의 유통기간 동안 미생물 안전기준에 부합하며 주스의 품질을 유지할 수 있는 바람직한 세척방법으로 판단된다. The aim of this study was to evaluate the microbial inhibitory activity and physicochemical quality of fresh carrot juice prepared with different environmentally-friendly washing methods during low temperature storage. Individual and combined treatments with sodium bicarbonate (baking soda, NaHCO₃) and citric acid were applied to carrots for 10 min. Tap water and 50 ppm of sodium hypochlorite (NaOCl) were used as the control. Combined treatment of 1% NaHCO₃ and 1% citric acid significantly reduced total aerobic counts and coliforms. In addition, combined treatment of 1% NaHCO₃ and 1% citric acid inhibited microbial growth for 7 days at 4°C and 10°C in a shelf-life study. There were no significant differences among the sanitizers in terms of °Brix, acidity, pH, and color. Changes in physicochemical quality were not significantly different by sanitizer but were affected by storage temperature. These results indicate that washing with combined treatment of 1% NaHCO₃ and 1% citric acid is an effective method to inhibit the microbial population and maintain physicochemical quality. Therefore, combined treatment of 1% NaHCO₃ and 1% citric acid can be effectively used to sanitize and prepare carrot juice without affecting other properties.

Effect of spark plasma sintering conditions on the thermoelectric properties of (Bi_0.25Sb_0.75)₂Te₃ alloys

Lim, Sang-Soon,Kim, Ju-Heon,Kwon, Beomjin,Kim, Seong Keun,Park, Hyung-Ho,Lee, Ki-Suk,Baik, Jeong Min,Choi, Won Jun,Kim, Dong-Ik,Hyun, Dow-Bin,Kim, Jin-Sang,Baek, Seung-Hyub Elsevier 2016 JOURNAL OF ALLOYS AND COMPOUNDS Vol.678 No.-

<P><B>Abstract</B></P> <P>As a field-assisted technique, spark plasma sintering (SPS) enables densification of specimens in a very short period of time compared to other sintering techniques. For high performance thermoelectric material synthesis, SPS is widely used to fabricate nanograin-structured thermoelectric materials by rapidly densifying the nanopowders suppressing grain growth. However, the microstructural evolution behavior of thermoelectric materials by SPS, another important process during sintering, has been rarely studied. Here, we explore SPS as a tool to control the microstructure by long-time SPS. Using p-type (Bi<SUB>0.25</SUB>Sb<SUB>0.75</SUB>)<SUB>2</SUB>Te<SUB>3</SUB> thermoelectric materials as a model system, we systematically vary SPS temperature and time to understand the correlations between SPS conditions, microstructural evolution, and the thermoelectric properties. Our results show that the relatively low eutectic temperature (∼420 °C) and the existence of volatile tellurium (Te) are critical factors to determine both microstructure and thermoelectric property. In the liquid-phase sintering regime, rapid evaporation of Te leads to a strong dependence of thermoelectric property on SPS time. On the other hand, in the solid-phase sintering regime, there is a weak dependence on SPS time. The optimum thermoelectric figure-of-merit (Z) of 2.93 × 10<SUP>−3</SUP>/K is achieved by SPS at 500 °C for 30 min. Our results will provide an insight on the optimization of SPS conditions for materials containing volatile elements with low eutectic temperature.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Spark plasma sintering (SPS) is used to synthesize the thermoelectric (Bi<SUB>0.25</SUB>Sb<SUB>0.75</SUB>)<SUB>2</SUB>Te<SUB>3</SUB>. </LI> <LI> Liquid phase and volatile element are a key for the microstructure and thermoelectric property. </LI> <LI> Thermoelectric figure-of-merit of 2.9 × 10<SUP>−3</SUP>/K is achieved at 500 °C for 30 min. </LI> </UL> </P>

Analysis of Lignans in Acanthopanax sessiliflorus Fruits and Their Fermented Wine by HPLC

Kim, Hye-Min,Kim, Ju-Sun,Cho, Seon-Haeng,Kang, Sam-Sik,Cheoi, Dae-Sung,Lee, Sang-Hyun The Korean Society of Medicinal Crop Science 2006 韓國藥用作物學會誌 Vol.14 No.5

High performance liquid chromatography (HPLC) was used for the determination of lignans, eleutherosides B and E, in Acanthopanax sessiliflorus fruits and their fermented wine. The lignans were quantified by a reversed-phase system using a gradient of $H_2O$ and acetonitrile as a mobile phase within 20 min. The analysis was successfully carried out within 20 min. The contents of eleutherosides Band E as main active principles of Acanthopanax species were measured in A. sessiliflorus fruits (1.15 and $8.49\;{\mu}g/mg$, respectively), their fermented wine (0.45 and $1.33\;{\mu}g/mg$, respectively) and wine residues (no detection).

기관지폐 이형성증의 임상 양상: 다기관 연구

성기혜 ( Ki Hye Sung ),김민희 ( Min Hee Kim ),김은령 ( Eun Ryoung Kim ),심재원 ( Jae Won Shim ),이정주 ( Jung Ju Lee ),임재우 ( Jae Woo Im ),진현승 ( Hyun Seung Jin ) 대한주산의학회 2009 Perinatology Vol.20 No.3

목적: 최근 극소 저출생 체중아의 생존율의 개선으로 기관지폐 이형성증(bronchopulmonary dysplasia, BPD)이 늘고 있다. 다기관 연구에 의해 전국적인 BPD의 역학, 임상 양상과 각 병원 간의 차이를 조사하여 향후 우리나라의 BPD 감소와 중증도를 줄이는 것을 목적으로 본 연구를 시행하였다. 방법: 2005년 6월부터 2007년 5월까지 건국대학교병원, 영등포 성애병원, 강북삼성병원, 중앙대학교병원, 건양대학교병원, 강릉아산병원의 신생아 집중 치료실에 입원하였던 신생아 4,476명을 대상으로 하였다. BPD의 진단 기준은 비전형적인 BPD를 포함하여 병인적인 분류를 하고 있는 Ogawa 등의 분류법을 이용하여 신생아 호흡 곤란 증후군(respiratory distress syndrome, RDS)과 전형적 또는 미만성 혼탁의 방사선 소견, 산전 감염의 유무에 따라 6가지 type으로 분류하였다. 또한 전체 신생아의 출생체중 분포와 생존율, 각 출생체중 군별 BPD의 발생률, 병태 비율, 사망률 등을 조사하고, 이 후 재택 산소요법 시행 여부와 미숙아 망막증, 괴사성 장염 등의 합병증 여부를 조사하였다. 결과: 생후 28일째 산소 치료가 필요한 신생아는 89명이었고, 이 중 Ogawa 분류법에 의한 BPD 환아는 70명(1.6%)이었으며, 특히 1,500 g 미만의 환아 237명 중 60명(25.3%)이었다. 생후 28일 이상 생존율은 98.7%이고, 사망 예는 없었으며 평균 재원 기간은 97.8±51.2일(43~405일)이었다. BPD는 900~999 g, 1,000~1,249 g의 체중 군에서 발생률이 각각 15명(21.4%)으로 가장 높았으며, 교정 36주 이후에도 산소투여가 필요한 중증 BPD의 경우 900~999 g의 체중 군에서 7명(23.3%)로 가장 높았다. Ogawa 분류법으로 BPD의 각 병태 비율로는 RDS 이후에 나타나는 I, II형이 각각 전체의 17예(24.3%), 44예(62.9%)로 대다수를 차지하였다. 이외에도 III`형은 2예(2.9%), IV형은 2예(2.9%), V형은 5예(7.1%)이었고, III형, VI형은 없었다. 재택 산소요법은 8예에서 시행되어 전체의 11.4%였으며, 이 중 BPD I형이 7예로 87.5%를 차지하였다. 미숙아 망막증은 35명(50.0%)에서 발생하였으며, 700 g 이하 신생아에서 9예(26.5%)로 가장 많았다. 또한 괴사성 장염은 3명(4.3%)이었다. 결론: 본 연구는 국내에서 처음으로 진행된 BPD의 전국적인 다기관 역학 조사로, 대상 신생아의 Ogawa 분류에 의한 BPD 유병률은 1.6% 이었고 1,500 g 미만 신생아의 25.3%이었으며, 전체 신생아의 BPD 70명 중 Ogawa 분류의 I, II형이 각각 24.3%, 62.9%로 대다수를 차지하였다. Purpose: As the neonatal intensive care advanced, the incidence of neonatal bronchopulmonary dysplasia (BPD) has increased. We conducted a multi-center investigation of the prevalence of BPD in six hospitals to investigate the epidemiology of BPD in Korea. Methods: Retrospective reviews ware performed for survival rate, prevalence of BPD of total 4,476 newborn infants who were admitted to neonatal intensive care unit in Konkuk university hospital, Sung-Ae General hospital, Kangbuk Samsung hospital, Chung-Ang university hospital, Konyang university hospital, and Gangneung Asan hospital between June, 2005 and May, 2007. By Ogawa, BPD was defined as oxygen dependency at 28 days after birth, with respiratory distress symptoms and the change of chest x-ray finding, and classified as 6 subtypes. Classic BPD was defined as oxygen dependency at 36 weeks of postmenstrual age. Results: Survival rate at 28 day after birth was 98.7%. BPD infants by Ogawa classification were 70 (1.6% of overall newborn infants), classic BPD infants were 30 (0.7%). Especially, among 237 preterm infants with birth weight less than 1,500 gram who survived to 28 days of life, 60 (25.3%) had BPD by Ogawa classification and 23 (9.7%) had classic BPD. In Ogawa classification, infants with RDS as type I and II, were 17 infants (24.3%) and 44 infants (62.9%). Home oxygen therapy was performed 8 infants (11.4%). Prevalence of retinopathy of prematurity was 35 infants (50.0%), necrotizing enterocolitis was 3 infants (4.3%), and intraventricular hemorrhage was 6 infants (8.6%). Conclusion: Prevalence of BPD infants was 1.6% of overall newborn, 25.3% of preterm infants with birth weight less than 1,500 gram. Among 70 BPD infants, BPD by Ogawa classification with history of RDS as type I and II were 24.3%, 62.9% as the majority of BPD. This study would be the first report of epidemiology of Korean BPD infants by multi-center study.

Structure–function studies of a plant tyrosyl-DNA phosphodiesterase provide novel insights into DNA repair mechanisms of <i>Arabidopsis thaliana</i>

Kim, Hoyeun,Na, Sang ,Hyeon,Lee, So-Young,Jeong, Young-Min,Hwang, Hyun-Ju,Hur, Jae ,Young,Park, Sang-Hyun,Woo, Je-Chang,Kim, Sang-Gu Portland Press Ltd. 2012 The Biochemical journal Vol.443 No.1

<P>TDP1 (tyrosyl-DNA phosphodiesterase 1), a member of the PLD (phospholipase D) superfamily, catalyses the hydrolysis of a phosphodiester bond between a tyrosine residue and the 3′-phosphate of DNA. We have previously identified and characterized the <I>AtTDP</I> gene in <I>Arabidopsis thaliana</I>, an orthologue of yeast and human <I>TDP1</I> genes. Sequence alignment of TDP1 orthologues revealed that AtTDP has both a conserved C-terminal TDP domain and, uniquely, an N-terminal SMAD/FHA (forkhead-associated) domain. To help understand the function of this novel enzyme, we analysed the substrate saturation kinetics of full-length AtTDP compared with a truncated AtTDP mutant lacking the N-terminal FHA domain. The recombinant AtTDP protein hydrolysed a single-stranded DNA substrate with <I>K</I><SUB>m</SUB> and <I>k</I><SUB>cat</SUB>/<I>K</I><SUB>m</SUB> values of 703±137 nM and (1.5±0.04)×10<SUP>9</SUP>M<SUP>−1</SUP>·min<SUP>−1</SUP> respectively. The AtTDP-(Δ1–122) protein (TDP domain) showed kinetic parameters that were equivalent to those of the full-length AtTDP protein. A basic amino acid sequence (RKKVKP) within the AtTDP-(Δ123–605) protein (FHA domain) was necessary for nuclear localization of AtTDP. Analysis of active-site mutations showed that a histidine and a lysine residue in each of the HKD motifs were critical for enzyme activity. Vanadates, inhibitors of phosphoryl transfer reactions, inhibited AtTDP enzymatic activity and retarded the growth of an <I>Arabidopsis tdp</I> mutant. Finally, we showed that expression of the <I>AtTDP</I> gene could complement a yeast <I>tdp1</I>Δ<I>rad1</I>Δ mutant, rescuing the growth inhibitory effects of vanadate analogues and CPT (camptothecin). Taken together, the results of the present study demonstrate the structure-based function of AtTDP through which AtTDP can repair DNA strand breaks in plants.</P>