Progress in the development of heating systems towards long pulse operation for KSTAR

Kwak, J.G.,Bae, Y.D.,Chang, D.H.,Chang, D.S.,Hong, B.G.,Hwang, C.K.,In, S.R.,Jeong, S.H.,Jin, J.T.,Jung, K.S.,Kim, B.R.,Kim, J.,Kim, S.K.,Kim, T.S.,Lee, D.W.,Lee, K.W.,Oh, B.H.,Seo, C.S.,Seo, M.S.,Yoo International Atomic Energy Agency 2007 Nuclear fusion Vol.47 No.5

<P>Construction of the Korea superconducting tokamak advanced research (KSTAR) tokamak is in its final phase. For the long-pulse KSTAR discharges, the ion cyclotron range of frequencies (ICRF) and neutral beam injection (NBI) heating systems are expected to play important roles through a selective heating of ions and electrons, control of the plasma pressure and current profiles, a core fuelling and beam diagnostics for the KSTAR. In addition, the ICRF system is expected to be used for possible discharge cleaning and assisting in the tokamak startup. In this paper, the recent progress in the development of the ICRF and the NBI heating systems is described. The four-strap ICRF antenna has been successfully tested for a voltage up to 41 kV for a pulse length of 300 s (to 46 kV for 20 s) in a test chamber. A prototype KSTAR NBI system has been developed. At present, the system has successfully produced a 1 MW beam power for 200 s and a 3.5 MW output beam power for 4 s.</P>

Evaluation of steam pasteurization in controlling <i>Salmonella</i> serotype Enteritidis on raw almond surfaces

Chang, S.-S.,Han, A.R.,Reyes-De-Corcuera, J.I.,Powers, J.R.,Kang, D.-H. Blackwell Publishing Ltd 2010 Letters in applied microbiology Vol.50 No.4

<P>Abstract</P><P>Aim: </P><P>To investigate the efficacy of steam pasteurization for reducing <I>Salmonella</I> serotype Enteritidis on raw almond surfaces.</P><P>Methods and Results: </P><P>Nonpareil almonds were inoculated to 10<SUP>7–8</SUP> CFU g<SUP>−1</SUP> with a <I>Salm</I>.<I> </I>Enteritidis cocktail (<I>Salm. </I>Enteritidis 43353, ME-13, ME-14) or <I>Salm</I>.<I> </I>Enteritidis phage type 30, dried overnight and subjected to steam treatments through a pilot-sized vertical pasteurization machine for 5, 15, 25, 35, 45, 55 and 65 s to investigate the effect of steam on a single layer of almond. Survival of <I>Salm</I>.<I> </I>Enteritidis was evaluated with tryptic soy agar and xylose lysine desoxycholate overlay for total and healthy cells, respectively. No significant differences (<I>P</I> > 0·05) in reduction were observed between the <I>Salm. </I>Enteritidis cocktail and <I>Salm</I>. Enteritidis PT 30 inoculum. Reduction of <I>Salm. </I>Enteritidis increased as a function of treatment time, with 25 s being sufficient to achieve a 5-log reduction. Discolouration and visible formation of wrinkles were observed following steam pasteurization of more than 35 s.</P><P>Conclusions: </P><P>Steam pasteurization of 25 s is sufficient to achieve a 5-log reduction of <I>Salm. </I>Enteritidis inoculated on raw almonds without visual quality degradation.</P><P>Significance and Impact of the Study: </P><P>Steam pasteurization is an effective alternative to reduce or prevent <I>Salm. </I>Enteritidis contamination on raw almonds.</P>

Modeling and simulation of HTS cables for scattering parameter analysis

Bang, S.S.,Lee, G.S.,Kwon, G.Y.,Lee, Y.H.,Chang, S.J.,Lee, C.K.,Sohn, S.,Park, K.,Shin, Y.J. North-Holland 2016 Physica. C, Superconductivity Vol.530 No.-

<P>Most of modeling and simulation of high temperature superconducting (HTS) cables are inadequate for high frequency analysis since focus of the simulation's frequency is fundamental frequency of the power grid, which does not reflect transient characteristic. However, high frequency analysis is essential process to research the HTS cables transient for protection and diagnosis of the HTS cables. Thus, this paper proposes a new approach for modeling and simulation of HTS cables to derive the scattering parameter (S-parameter), an effective high frequency analysis, for transient wave propagation characteristics in high frequency range. The parameters sweeping method is used to validate the simulation results to the measured data given by a network analyzer (NA). This paper also presents the effects of the cable-to-NA connector in order to minimize the error between the simulated and the measured data under ambient and superconductive conditions. Based on the proposed modeling and simulation technique, S-parameters of long-distance HTS cables can be accurately derived in wide range of frequency. The results of proposed modeling and simulation can yield the characteristics of the HTS cables and will contribute to analyze the HTS cables. (C) 2016 Elsevier B.V. All rights reserved.</P>

수정진동자에 의한 Polypyrrole중합막의 Electrochromatic 현상

김정명,김종민,장상목,장정수,권영수 경북대학교 센서기술연구소 1995 센서技術學術大會論文集 Vol.6 No.1

This paper shows that the electrochemical mass transport in polypyrrole(Ppy) thin film deposited electrode, involves the rheological change and electrochromatics of the Ppy. These changes can be detected by measuring the resonant frequency, resonant resistance, and UV spectrum of a Ppy deposited quartz crystal. A Ppy deposited quartz crystal is used and measured the cyclic voltammograms in KClO_(4) electrolyte solution. The changes of the resonant frequency and resonant resistance showed that mass transport and viscoelastic changes occur in the Ppy film. The absorption change means that the electrochromatics change occurs also in the Ppy film

Temperature and air pollution affected tree ring δ¹³C and water-use efficiency of pine and oak trees under rising CO₂ in a humid temperate forest

Kwak, J.H.,Lim, S.S.,Lee, K.S.,Viet, H.D.,Matsushima, M.,Lee, K.H.,Jung, K.,Kim, H.Y.,Lee, S.M.,Chang, S.X.,Choi, W.J. Elsevier 2016 Chemical geology Vol.420 No.-

<P>To better predict forest productivity under rising atmospheric CO2 concentration ([CO2]), it is critical to understand how intrinsic water-use efficiency (WUEi) and its relationship with tree growth are affected by the concomitant changes in environmental conditions such as precipitation, temperature, and air pollution that either enhance or undermine any potential CO2 fertilization effect. We investigated changes in delta C-13 and WUEi in annual rings and basal area increment (BAI) of Pinus densiflora (from 1968 to 2007) and Quercus variabilis (from 1970 to 2007) trees in relation to precipitation, temperature, and air pollution in a humid temperate forest. The WUEi of P. densiflora increased by 39.9%, whereas that of Q. variabilis did not change over time in the study period. The WUEi was not affected by precipitation for both species but increased (P < 0.001) with temperature for P. densiflora and with SO2 emissions for both species. Multiple regression models suggested that the effect of [CO2] on tree growth was much higher than temperature; however, for the period (1998 to 2007) when SO2 emissions data were available, SO2 emission was the driver of changes in BAI and WUEi, and temperature effects became stronger than [CO2]. Overall, BAI and WUEi were positively (P < 0.001) correlated for P. densiflora, but not for Q. variabilis. We conclude that temperature and air pollution rather than precipitation were key determinants of WUEi at the study site and that the two species had contrasting responses to environmental changes. (C) 2015 Elsevier B.V. All rights reserved.</P>

1987년 한국에서 발생한 렙토스피라병의 혈청역학적 조사

이증훈,박영수,이우곤,김석용,정선식,우준희,박성광,박경희,송영욱,김선영,기정일,최두혁,강성귀,김주완,최강원,김우열,최명식,최인학,장우현,윤성열 대한감염학회 1988 감염 Vol.20 No.3

Human leptospirosis was an unfamiliar disease in Korea until 1984 that outbreak of leptospirosis occurred among farmers and soldiers after field works for harvesting rice. During that time, Lee and Jo confirmed the first Korean cases of leptospirosis by serological test, isolation of causative agent and autopy findings. Afterward several outbreaks occurred also during autumn especially after flood in every years and some characterisitcs of leptospirosis in Korea such as clinical manifestations, serotypes and seroepidemiological features has been revealed by many investigators. Because of the major mode of transmission between rodents and human is by direct contact with leptospiral urine of rodents or contaminated soil by the urine, leptospirosis in Korea has been primarily a disease of person in occupations heavily exposed to contaminated soil or infected urine such as farmer, army and etc. Therefore it seems that leptospirosis is one of the main communicable diseases to be controlled urgently in Korea, for an agricultural people account for almost half of total Korean people. For clarifying the seroepidemiological patterns of human leptospirosis in Korea by sex, month region and main reacting serovars of L. interrogans among acute febrile disease occurred in 1987, 1,773 patient's sers with acute febrile episodes were tested by microagglutination test using 19 representative strains of leptospiral serogroup as antigen. All of those sera were collected from 10 collaborative clinics located in Kyunggi, Kangwon, Chungbuk, Chungnam, Chonbuk, Chonnam province and Seoul. The results wee summerized as follows. 1) Among 1,773 sera of patients with acute febrile episodes, 219 (12.4%) were seropositive to L. interrogans, 487(27.5%) to R. tsutsugamushi, 241(13.6%) to R.typhi and 160(90.0%) to Hantaan virus. 2) Among seropositives to L.interrogans, the male outnumbered the female, 65% and 35%. 3) For age distribution, 26.9% of seropositives to L.interrogans were fifties, 19.6% were forties, 9.1% were sixties, 5.9% were thirties and 4.1% were twenties. 4) Eighty three percent of seropositives had occurred between September and October in 1987 with a peak in September. 5) Main leptospiral serovars reactive to patient's sera were Icterohaemorrhagiae(54.3%), Canicola(31.0%), CH-48(13.2%), Tarassovi(0.9%)and Cynopteri(0.5%). 6) For regional distribution, 65.8% of seropositives to L.interrogans were residents from Chonbuk, 12.3% were Chonnam, 7.3% were Chungnam, 5.5% were Kyunggi and 1.4% were Kangwon.

Carbon nanotube-based biosensor for detection of matrix metallopeptidase-9 and S-100B

Lee, H.S.,Oh, J.S.,Chang, Y.W.,Park, Y.J.,Shin, J.S.,Yoo, K.H. 한국물리학회 2009 Current Applied Physics Vol.9 No.4_SUP

We fabricated carbon nanotube (CNT)-based biosensor with field effect transistor structure for detection of matrix metallopeptidase-9 (MMP-9) and S-100B. To minimize contact effects, the metal electrodes were passivated with SiO<SUB>x</SUB> film, and anti-MMP-9 and S-100B antibody were immobilized on the CNT surface using a chemical linker. When MMP-9 or S-100B antigen was added to bind anti-MMP-9 or S-100B antibody, the decrease in electrical conductance was observed. We have also investigated the dependence of MMP-9 and S-100B concentration on the conductance change. A linear relationship was found between the conductance and the concentration in semi-logarithm scale.

유전자 알고리즘을 이용한 InGaP/GaAs HBT 소신호 등가회로 파라미터 추출

장덕성(D.S. Chang),문종섭(J.S. Moon),박철순(C.S. Park),윤경식(K.S. Yoon) 한국지능시스템학회 2001 한국지능시스템학회논문지 Vol.11 No.6

에미터 크기가 2×10 μm²인 InGaP/GaAs 이종접합 바이폴라 트랜지스터의 T자 모양으로 연결된 등가회로 요소를 추출하기 위하여, 경계 구간 설정이 개선된 유전자 알고리즘을 채택하였다. 이 소신호 모델 파라미터를 유전자 알고리즘을 사용하여, 다양한 순방향 바이어스에서 측정한 S-파라미터들로부터 추출하였다. 추출된 값들은 물리적인 의미와 일관성을 보여준다. 모델 S-파라미터는 측정 S-파라미터와 2GHz- 26.5GHz의 주파수 범위에서 잘 일치한다. The present approach based on the genetic algorithm with improved selections of bounds was adopted to extract a bridged T equivalent circuit elements of a 2×10 μm² InGaP/GaAs HBT. The small-signal model parameters were extracted using the genetic algorithm from S-parameters measured at different frequencies under multiple forward-active biases, which demonstrate physically meaningful values and consistency. The agreement between the measured and modeled S-parameters is excellent over the frequency range of 2 to 26.5GHz.

Phase II study of S-1 combined with oxaliplatin as therapy for patients with metastatic biliary tract cancer: influence of the <i>CYP2A6</i> polymorphism on pharmacokinetics and clinical activity

Kim, K-p,Jang, G,Hong, Y S,Lim, H-S,Bae, K-s,Kim, H-S,Lee, S S,Shin, J-G,Lee, J-L,Ryu, M-H,Chang, H-M,Kang, Y-K,Kim, T W Nature Publishing Group 2011 The British journal of cancer Vol.104 No.4

<P><B>Background:</B></P><P>Advanced biliary cancer is often treated with fluoropyrimidine-based chemotherapy. In this study, we evaluated the efficacy and tolerability of a combination of S-1, an oral fluoropyrimidine prodrug, and oxaliplatin in patients with metastatic biliary cancer.</P><P><B>Methods:</B></P><P>Patients with histologically confirmed metastatic biliary cancer and no history of radiotherapy or chemotherapy were enrolled. Oxaliplatin was administered intravenously (130 mg m<SUP>−2</SUP>), followed by 14-day administration of oral S-1 (40 mg m<SUP>−2</SUP> twice daily) with a subsequent 7-day rest period every 21 days. Pharmacokinetic analysis of S-1 was performed at cycle 1. Patients were genotyped for <I>CYP2A6</I> polymorphisms (<SUP>*</SUP>1, <SUP>*</SUP>4, <SUP>*</SUP>7, <SUP>*</SUP>9 or <SUP>*</SUP>10), and pharmacokinetic and clinical parameters compared according to the <I>CYP2A6</I> genotype.</P><P><B>Results:</B></P><P>In total, 49 patients were evaluated, who received a median of four cycles. The overall response rate was 24.5%. Median progression-free and overall survival was 3.7 and 8.7 months, respectively. The most common haematological grade 3 out of 4 toxicity was neutropenia (14%), while non-hematological grade 3 out of 4 toxicities included anorexia (14%), nausea (12%), asthenia (10%), vomiting (10%), and diarrhoea (4%). Biotransformation of S-1 (AUC<SUB>0−24 h</SUB> of 5-fluorouracil/AUC<SUB>0−24 h</SUB> of tegafur) was 1.85-fold higher for the <I>*1/*1</I> group than for the other groups (90% confidence interval 1.37–2.49). Diarrhoea (<I>P</I>=0.0740), neutropenia (<I>P</I>=0.396), and clinical efficacy (response rate, <I>P</I>=0.583; PFS, <I>P</I>=0.916) were not significantly associated with <I>CYP2A6</I> genotype, despite differences in 5-FU exposure.</P><P><B>Conclusion:</B></P><P>The combination of S-1 and oxaliplatin appears to be active and well tolerated in patients with metastatic biliary cancer, and thus is feasible as a therapeutic modality. <I>CYP2A6</I> genotypes are associated with differences in the biotransformation of S-1. However, the impact of the <I>CYP2A6</I> polymorphism on variations in clinical efficacy or toxicity requires further evaluation.</P>

Pseudomonas sabulinigri sp. nov., isolated from black beach sand

Kim, K.-H.,Roh, S. W.,Chang, H.-W.,Nam, Y.-D.,Yoon, J.-H.,Jeon, C. O.,Oh, H.-M.,Bae, J.-W. Microbiology Society 2009 International journal of systematic and evolutiona Vol.59 No.1

<P>A novel Gram-negative, aerobic, motile, short rod-shaped bacterium, designated J64T, was isolated from black sand collected from Soesoggak, Jeju Island, Korea. Cells grew at 4-37 degrees C, at pH 5.5-10.0 and with 0-10 % NaCl. The strain was found to be oxidase- and catalase-positive. Phylogenetic analyses showed that strain J64T belongs to the genus Pseudomonas, forming a monophyletic group with Pseudomonas pachastrellae, Pseudomonas pertucinogena and 'Pseudomonas denitrificans'. The 16S rRNA gene sequence similarity between strain J64T and type strains of all Pseudomonas species with validly published names was below 96.6 %. Low levels of DNA-DNA relatedness were found with respect to type strains of P. pachastrellae and P. pertucinogena, supporting the classification of strain J64T within a novel species of the genus Pseudomonas. Strain J64T contained C(18 : 1)omega7c (37.2 %), C(16 : 0) (20.4 %), summed feature 3 (17.4 %; comprising iso-C(15 : 0) 2-OH and/or C(16 : 1)omega7c) and C(12 : 0) (7.6 %) as major cellular fatty acids. On the basis of the phenotypic and phylogenetic data, strain J64T represents a novel species of the genus Pseudomonas, for which the name Pseudomonas sabulinigri sp. nov. is proposed. The type strain is J64T (=KCTC 22137T =JCM 14963T).</P>