남조류와 녹조류에서의 수소생산을 위한 배양 조건의 최적화

윤종현(J. H. Yoon),공경택(K. T. Kong),심상준(S. J. Sim),김미선(M.S. Kim),박태현(T. H. Park) 한국수소및신에너지학회 2002 한국수소 및 신에너지학회논문집 Vol.13 No.4

Blue-green algae and green algae have the unique characteristic of using CO₂ in the air as a carbon source and solar energy as an energy source and producing H₂ with water used as the primary electron donor. The cells take up CO₂ first to produce cellular substances, which are subsequently used for H₂ production. Since the optimal operating conditions for the CO₂ uptake and H₂ production are different, a two-stage system can be effectively employed to separate these two phases. For the efficient production of H₂ in the second stage, in this study, the culture condition of blue-green algae was optimized for the effective CO₂ uptake and cell growth in the first stage, and high cell density culture was carried out using repeated injections of CO₂. In green algae, the amount and patterns of organic compounds have a connection with growth stage or dark fermentation time. The hydrogen production was greatly influenced by dark fermentation time.

SEARCH FOR PULSED γ-RAY EMISSION FROM GLOBULAR CLUSTER M28

Wu, J. H. K.,Hui, C. Y.,Wu, E. M. H.,Kong, A. K. H.,Huang, R. H. H.,Tam, P. H. T.,Takata, J.,Cheng, K. S. IOP Publishing 2013 ASTROPHYSICAL JOURNAL LETTERS - Vol.765 No.2

<P>Using the data from the Large Area Telescope on board the Fermi Gamma-ray Space Telescope, we have searched for gamma-ray pulsations from the direction of the globular cluster M28 (NGC 6626). We report the discovery of a signal with a frequency consistent with that of the energetic millisecond pulsar (MSP) PSR B1821-24 in M28. A weighted H-test test statistic of 28.8 is attained, which corresponds to a chance probability of similar to 10(-5) (4.3 sigma detection). With a phase-resolved analysis, the pulsed component is found to contribute similar to 25% of the total observed gamma-ray emission from the cluster. However, the unpulsed level provides a constraint for the underlying MSP population and the fundamental plane relations for the scenario of inverse Compton scattering. Follow-up timing observations in radio/X-ray are encouraged to further investigate this periodic signal candidate.</P>

DISCOVERY OF AN ULTRACOMPACT GAMMA-RAY MILLISECOND PULSAR BINARY CANDIDATE

Kong, Albert K. H.,Jin, Ruolan,Yen, T.-C.,Hu, C.-P.,Hui, C. Y.,Tam, P. H. T.,Takata, J.,Lin, L. C. C.,Cheng, K. S.,Park, S. M.,Kim, C. L. IOP Publishing 2014 ASTROPHYSICAL JOURNAL LETTERS - Vol.794 No.2

<P>We report multi-wavelength observations of the unidentified Fermi object 2FGL J1653.6-0159. With the help of high-resolution X-ray observations, we have identified an X-ray and optical counterpart to 2FGL J1653.6-0159. The source exhibits a periodic modulation of 75 minutes in the optical and possibly also in the X-ray. We suggest that 2FGL J1653.6-0159 is a compact binary system with an orbital period of 75 minutes. Combining the gamma-ray and X-ray properties, 2FGL J1653.6-0159 is potentially a black-widow-/redback-type gamma-ray millisecond pulsar (MSP). The optical and X-ray light curve profiles show that the companion is mildly heated by the high-energy emission and that the X-rays are from intrabinary shock. Although no radio pulsation has yet been detected, we estimated that the spin period of the MSP is similar to 2 ms based on a theoretical model. If pulsation can be confirmed in the future, 2FGL J1653.6-0159 will become the first ultracompact rotation-powered MSP.</P>

전신 골밀도와 기능 상실 치율 및 하악골 골소주 흡수 양상의 상관 관계

공선애,송용준,노재형,안종인,고영규,김종화,이희철 인제대학교 1996 仁濟醫學 Vol.17 No.1

1993년 3월부터 1995년 6월까지 부산백병원 치과에 내원한 40세 이상 65세 이하의 연령층에 속하는 여성 환자를 대상으로 임상 검사 및 방사선학적 검사를 시행한 결과 치주병에 이환된 치아의 비율이 20% 이하인 30명을 선정하여 이화학적 검사, 치아 파노라마 단층 촬영을 이용한 방사선학적 검사 및 LUNAR DPX 골밀도 측정기를 이용한 전신 골밀도 측정을 시행하였다. 이를 통한 검사 결과를 분석하면서 전신 골밀도 수준과 기능 상실치율 및 하악골 내 골소주의 흡수 양상 간의 상관 관계를 평가하여 다음과 같은 결과를 얻었다. 1.골대사의 지표인 칼슘, 무기인, 알칼리성 인산화효소를 측정하여 전신 골밀도와의 상관 관계를 검증하였으나 유의한 상관 관계는 없었다 (P>0.05). 2.전신 골밀도 분석 결과는 기능 상실치수 및 기능 상실치율에 유의한 상관 관계를 가지고 있었다 (연령에 의한 영향을 보정함)(P=0.0050). 3.30명 환자의 기능 상실치율은 평균 33.7%였으며 치아 파노라마 단층 촬영을 분석한 결과 이공 주변부의 골소주 흡수양상은 현저하여 Diffuse resorption type, Moth-eaten type, Limited(round) resorption type으로 분류 가능하였으나 각 군별로 전신 골밀도 분석 평균의 차이는 없었다(P>0.05). The author selected 30 women whose periodontal disease rate was no more than 20%. They were the patients who have visited at the Dept. of Dentistry in Paik hospital from 1993 to 1995. Biochemical examination, dental panoramic tomogram check and toal body bone density check were done using LUNAR DPX bone densitometer. The results were analysed by total body bone density level, function loss teeth rate and mandibular trabeculi resorption pattern. Then, the author accessed the correlation on the basis of their results. The following observations were made ; 1.Calcium, phosphorus and alkaline phosphatase levels were not correlated with tonal body bone density (P>0.05) 2.There was a good correlation between function loss teeth rate and total body bonedensi ty(corrected by age) (P = 0.0050) 3.We analysed dental panoramic tomograms of 30 women whose periodontal disease rate was no more than 20%. The mean function loss teeth rate in 30 patients was 33.7%. So we could divide mandibular trabeculi resorption pattern into 3-types ; Diffuse resorption type, Moth-eaten type, Limited (round) resorption type. But, there was no correlation between each resorption pattern and total body bonedensity (P>0.05).

Comparative studies on steam gasification of ash-free coals and their original raw coals

Kong, Y.,Kim, J.,Chun, D.,Lee, S.,Rhim, Y.,Lim, J.,Choi, H.,Kim, S.,Yoo, J. Pergamon Press ; Elsevier Science Ltd 2014 INTERNATIONAL JOURNAL OF HYDROGEN ENERGY - Vol.39 No.17

Catalytic gasification of raw coals at mild condition is not realized yet mainly due to deactivation of catalysts via their irreversible interaction with mineral matters in coal. As a means to achieve repeated use of catalysts, four different ash-free coals (AFCs) containing less than 0.2 wt% ash are produced in this work. Steam gasification of ash-free coals (AFCs) and their parent raw coals of various ranks ranging from lignite (Eco) to coking coal (Posco) is performed in a fixed bed reactor at 700-900 <SUP>o</SUP>C. Regardless of the rank of the parent raw coals, all the AFCs behave like a highly carbonized coal such that their gasification rate are similarly slow and they exhibit relatively low H<SUB>2</SUB>/CO ratio. The steam gasification and associated CO to CO<SUB>2</SUB> conversion of the AFCs are, however, significantly enhanced by K<SUB>2</SUB>CO<SUB>3</SUB>, resulting in the higher H<SUB>2</SUB>/CO and CO<SUB>2</SUB>/CO molar ratio.

A<i>NuSTAR</i>Observation of the Gamma-Ray Emitting Millisecond Pulsar PSR J1723-2837

Kong, A. K. H.,Hui, C. Y.,Takata, J.,Li, K. L.,Tam, P. H. T. American Astronomical Society 2017 The Astrophysical journal Vol.839 No.2

<P>We report on the first NuSTAR observation of the gamma-ray emitting millisecond pulsar binary PSR J1723-2837. X-ray radiation up to 79 keV is clearly detected, and the simultaneous NuSTAR and Swift spectrum is well described by an absorbed power law with a photon index of similar to 1.3. We also find X-ray modulations in the 3-10, 10-20, 20-79, and 3-79 keV bands at the 14.8. hr binary orbital period. All of these are entirely consistent with previous X-ray observations below 10 keV. This new hard X-ray observation of PSR J1723-2837 provides strong evidence that the X-rays are from the intrabinary shock via an interaction between the pulsar wind and the outflow from the companion star. We discuss how the NuSTAR observation constrains the physical parameters of the intrabinary shock model.</P>

Broad-band high-energy emissions of the redback millisecond pulsar PSR J2129-0429

Kong, Albert K H,Takata, Jumpei,Hui, C Y,Zhao, J,Li, K L,Tam, P H T Oxford University Press 2018 MONTHLY NOTICES- ROYAL ASTRONOMICAL SOCIETY Vol.478 No.3

Fabrication and electrochemical properties of hemisphere structured 3D Li(Li0.2Mn0.54Co0.13Ni0.13)O2 cathode thin film for all-solid-state lithium battery.

Yim, H,Kong, W Y,Yoon, S J,Kim, Y C,Choi, J W American Scientific Publishers 2013 Journal of Nanoscience and Nanotechnology Vol.13 No.5

<P>The Li[Li0.2Mn0.54Ni0.13Co0.13]O2 cathode thin films were deposited on planar, hemisphere, linked hemisphere, and isolated hemisphere structured Pt current collector thin films to investigate the effect of 3-dimensional (3-D) structure for the electrochemical properties of active cathode thin films. The films of linked hemisphere structure shows the highest initial discharge capacity of 140 microA h/cm2-microm which is better than those of planar (62 microA h/cm2-microm), hemisphere (94.6 microA h/cm2-microm), and isolated hemisphere (135 microA h/cm2-microm) films due to increase of surface area for cathode thin films. Linked hemisphere shows the biggest capacity and the best retention rate because 6 nanobridges of each hemisphere bring strong connection.</P>

일부농촌지역 손상 및 중독발생의 역학적특성

이진이,조은정,이인숙,공하정,김한규,김정순,권동석 서울大學校保健大學院 1997 國民保健硏究所硏究論叢 Vol.7 No.2

The mortality and morbidity caused by injury and poisoning has been a major public health problem in Korea. this study was carried out to get information indispensable in developing prevention srategies peculiar to Korean rural area. In this study 444 people of 14 households, who are living in five rural villages of Chooncheon City, Kang-Won Province, were interviewed in accordance with structured questionaire by MPH students and teaching staff of School of Public Health SNU during the field training course of 1997 academic year. The results obtained are summarized as follows: 1. The age-standardized annual incidence rates of injury and poisoning per 100 persons surveyed were 19.8 in males and 14.1 in females. The difference between sex was not statistically significant. The age specific incidence rate generally revealed that the incidence increased as age advanced, suggesting vulnerability of aging to the accident. 2. The incidence rates of injuries and poisoning were higher among the people living in traditional Korean-style house than those living in others(a Westen-style house), the accident occurred more frequently in kitchen and toilet than other places within the house, and the differences in the incidence were statistically significant. 3. The places where most of injuries and poisonings occurred were road and cultivating area(27.5% each) among males, and cultivating area(42.5%), indoor and road(15.7% each) among females. 4. The occurrence of the injuries and poisoning were clustered in intensive farming season in males, whereas farmong season and winter in females. The injury and poisoning occurred more frequently in the afternoons of the day although the clustering of thd accidents by time showed different pattern by sex and type. 5. The laceration and stab wound were the most frequent nature of injuries in both males and females. On the other hand abrasion, organ damage and amputation were more frequent among males but concussion and fracture were more frequent among females. 6. Incidence rates of injuries and poisoning by cause were higher in traffic accidents and farming among males, though falls among females. The cause specific incidence rate by age was high in traffic accidents for 10-2 year age group(62.5%), and in falls for 30-59 year age group and the aged peole older than 60 years. 8. In the management pattern, 36 percents of the injuries and poisonings wer self-treated and the 30 percents of those received medical care in hospitals and clinics, the medical expenditure being over 100,000 won in 25% of injured and the duration of the treatment over 2 weeks in 46%. The results obtained indicate that organized community effort is urgently required to prevent injuries and poidsonings in rural area.

한우 경제형질에 미치는 Mitochondrial DNA D-loop 영역의 염기서열 변이효과

오재돈,윤두학,공홍식,임현진,이학교,조병욱,홍기창,전광주 한국동물자원과학회 2003 한국축산학회지 Vol.45 No.6

This study was performed to analyse the sequences of variations of mtDNA D-loop and their effects on carcass traits in Hnawoo(Korean cattle). The resulting sequences were compared with perviously published sequences for other cattle breeds(GenBank J01394). The PCR was used to amplify a total of 964 bp between nucleotide 15758 and 383 within D-loop region of mtDNA using specific primers. Twenty five polymorphic sites by nucleotide substitution were found in mtDNA of Hanwoo. The frequencies of positions at 169, 16042, 16093. 16119, 16255 and 16302 nt with high levels of sequence polymorphism were 0.891, 0.117, 0.109, 0.182, 0.197 and 0.117, respectively. The substitution effect at 169 and 16119 nt was found significant on marbling score. Also substitution effect at 169 and 16042 nt was highly significant(p<0.01) on backfat, thickness. Polymorphisrn of mtDNA sequence in D-loop region could be useful for the analysis of cytoplasmic genetic variation and associations with the other economically important traits and maternal lineage analysis in Hanwoo.