• Bulletin of the Korean Chemical Society
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• 제35권8호
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• pp.2367-2370
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• 2014

"Cat's eye"-shaped $[^{57}Co]CoO@SiO_2$ core-shell nanostructure was prepared by the reverse microemulsion method combined with radioisotope technique to investigate a potential imaging agent for a single photon emission computed tomography (SPECT) in nuclear medicine. The core cobalt oxide nanorods were obtained by thermal decomposition of $Co-(oleate)_2$ precursor from radio isotope Co-57 containing cobalt chloride and sodium oleate. The $SiO_2$ coating on the surface of the core cobalt oxide nanorods was produced by hydrolysis and a condensation reaction of tetraethylorthosilicate (TEOS) in the water phase of the reverse microemulsion system. In vivo test, micro SPECT image was acquired with nude mice after 30 min of intravenous injection of $[^{57}Co]CoO@SiO_2$ core-shell nanostructure.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2005년도 춘계 학술대회논문집
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• pp.70-73
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• 2005

The HANARO, multi-purpose research reactor, 30 MWth open-tank-in-pool type, is planning to produce a fission moly-99 of radio isotopes, a mother nuclide of Tc-99m, a medical isotope and is under developing a target handling tool for loading and unloading it in a circular flow tube (OR-5). A guide tube is extended from the reactor core to the top of the reactor chimney for easily loading the target under the reactor normal operation. But active coolant through the core can be quickly raised up to the top of the chimney through the guide tube. The jet flow was suppressed in the guide tube after reducing the inner diameter of a flow restriction orifice installed in the OR-5 flow tube for adding the pressure difference in the flow tube after unloading the target. This paper describes an analytical analysis to calculate the flow distribution in the core of the HANARO after suppressing the jet flow of the guide tube. As results, it was confirmed through the analysis results that the flow distribution in the core of the HANARO were not adversely affected.

• 자원환경지질
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• 제33권3호
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• pp.195-204
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• 2000

order to investigate physical characteristics and element concentrations of sediments, coastal bottom sediments were collected at 20 stations in the vicinity of Youngkwang Nuclear Power Plant. After air drying of samples in the laboratory. article size distribution was examined by Master sizer (X-350F), radio-activity by HPGe ${\gamma}$-spectrphotometer, and element concentrations by ICP-AES and AAS. According to particle size analysis , sediments are mainly composed of silt fraction weith 23% of sand, 65% of silt and 12% of clay on average. Most sediments are derived from muddy environment that silt dominates with the characteristics of 5.3${\varsigma}$ mean particle size, poorly sorted, very fine skewed and lepto-kurtic. Only two sediments are well sorted with sandy silt owing to wind, winnowing action, tide and current andits complex reactions. Element concentrations in the coastal bottom sediments are relatively high at finer sediment and show significant relationship with grain size. Index of geoaccumulation by heavy metals at every sampling station is classified as practically unpolluted. The radioactivities of the sediments were measured for 15 isotope elements, and 2 elements of K-40 and Cs-137 were detected in most sediments. The K-40 is the natural nuclide and the artificial nuclide of Cs-137 was thought to be derived from the fallout of past nuclear weapon test. The results of correlation coefficient between grain size and radioactivity shows that the activity of Cs-137 significantly increases in finer grain.

• 대한방사성의약품학회지
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• 제2권1호
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• pp.9-16
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• 2016

Carbon-11 is one of the most sensitive and desirable positron emission tomography radio-isotope, which offers the capacity to be incorporated, through a covalent bond, into biologically active molecules without altering their biological properties. Carbon-11 can be obtained from the cyclotron with two different chemical forms: $[^{11}C]CO_2$ and $[^{11}C]CH_4$. [$^{11}C$]Methyl iodide has been widely used as a highly reactive labelling precursor that can be applied to label carbon-11 with biologically active molecules via alkylation of N-, O-, or S-nucleophiles. A more recent and still challenging labeling method is transition metal mediated $^{11}C$-carbonylation. Advances in organic chemistry, radiochemistry and improved automated techniques greatly encourage researchers to develop more carbon-11 labelled radiotracers for molecular imaging studies. This mini-review will introduce a historical track of carbon-11 chemistry combining with examples and its role in near future.

• Nuclear Engineering and Technology
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• 제13권3호
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• pp.145-152
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• 1981

산화제 첨가없이 고온동위원소 교환법으로 오르토 요오도히퓨린산(OIH)을 방사성요오드로 표지하면 효과적이라고 하나 그 교환메카니즘은 불확실하였다. 본 연구에서는 OIH와 $^{125}$/ $I^{-}$ 및 OIH와 $^{125}$/ $I_2$사이의 동위원소 교환반응을 두 다른 온도에서 진행시켜 교환속도 상수와 활성화파라미터들을 방사종이 크로마토그래피법으로 측정함으로써 반응속도론적으로 고찰하였다. OIH표지반응 때의 부산물로 알려진 오르토요오도벤조산(OIB)에 대해서도 같은 방범으로 진행시켰던바 교환속도 상수가 큰 순서는 OIB...$^{125}$/ $I^{-}$>OIB...$^{125}$/ $I_2$>OIH..$^{125}$/ $I^{-}$>OIH...$^{125}$/ $I_2$이었고 OIH의 활성화 파라미터가 일반적으로 OIB의 그것들보다 컸다. ($\Delta$H$\neq$$_{OIH}$>$\Delta$H$\neq$$_{OIB}$, $\Delta$S$\neq$$_{OIH}$>$\Delta$S$\neq$$_{OIB}$). 조건에 따라서는 친전자적 교환메카니즘도 가능하겠으나 위의 결과는 고온 교환반응에서 친핵적 교환메카니즘이 압도적임을 말해주었다. 그와같은 원인은 OIH의 CONHC $H_2$COOH의 오르토치환기 효과에 의한 수소결합형 전이상태 생성이 용이하기 때문이라고 보았다. 따라서 고온 교환법은 환원제가 함유되지 않은 $^{131}$ I가 생산되지 않는 작은 연구기관에서의 Hippuran표지 화합물 제조에 효과적임을 알수 있었다. 알수 있었다.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2008년도 춘계 종합학술대회 논문집
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• pp.289-293
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• 2008

본 연구에서는 하천에 유입된 오염물질의 거동 및 확산특성을 파악하기 위하여 실제 하천에서 RI(Radioactive Isotope) 추적자를 이용하여 오염물 확산을 실측하고 그 결과를 수치모형과 비교분석하였다. 연구대상 수로구간은 금강 상류지역의 용담댐 부근 남대천 합류지점으로부터 하류로 약 2km구간에서 실험을 하였으며, 수치모형으로는 RMA-2(Resource Modeling Associates), RMA-4를 사용하였다. RI를 이용한 현장실험은 모델링을 적용한 지역과 동일 지역에서 실험을 실시하였고, 각 구간의 간격은 1km로 정하되 현장 사정에 따라 차이를 조금 두어 RI계측기를 통한 1초간격의 농도 데이터를 계측하였다. 계측결과는 수치모형의 결과와 실제 하천에서의 확산범위 및 확산에 큰 영향을 미치는 확산계수 변화에 따른 농도 분포를 비교 분석하였다. 본 연구를 통해 확산계수가 하천의 오염전파에 미치는 영향과 실측된 농도 데이터를 통해 최초 및 최대농도 도달시간을 파악할 수 있었고, 이것으로 인하여 확산계수를 산정을 할 수 있는 기초자료를 마련하였다.

• Journal of Korean Neurosurgical Society
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• 제30권11호
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• pp.1320-1323
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• 2001

SAPHO syndrome is an acronym for an increasingly recognized syndrome of synovitis, acne, pustulosis, hyperostosis, and osteitis. Most of the previously reported case are from Japan and Europe. The authors report a case of SAPHO syndrome in Korean female who presented with extrasternal neurologic symptoms. A 60-year-old female with thoracic and right chest wall pain presented with the sternocostoclavicular hyperostosis, and recurrent aseptic osteitis. Previously, she had hystrectomy and thyroidectomy due to uterine malignancy 25 years ago. Also, she started to take medications for palm and sole pustulosis 7 days prior to admission. Through evaluation of clinical, radiological, serological studies, studies was done along with bone needle biopsy for the biological reassessment. The hyperostosis was found in the pedicles of thoracic 8, 9, 10 vertebrae and sternoclavicular joint. Radio-isotope bone scan showed an accumulation of tracer in thoracic vertebra. The bone biopsy from these site showed increased osseous turnover, thickening of trabeculae accompanied by mild acculuation of granulation tissue and round cell infiltration, compatible with mild chronic inflammation with marrow fibrosis. The patient showed good response to conservative management. The authors report a case of SAPHO syndrome with thoracic radiculopathy. It is considered that SAPHO syndrome is related to spondyloarthropathy, and appears to have benign disease process with good prognosis.

• 대한토목학회논문집
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• 제14권1호
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• pp.203-216
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• 1994

현재 국내에서 사용중인 흙의 다짐관리 방법에는 실험실내에서 시행하는 흙의 다짐 시험 (KSF 2312)과 함수량시험(KSF 2306), 현장에서 모래치환법에 의한 흙의 단위중량 시험 방법 (KSF 2311)이 었다. 이러한 시험방법들은 소요시간이 길고 작업이 번잡하므로 최근과 같이 빠른 사공속도가 요구되는 대규모 토공관리에는 부적합하며 측정자의 개인오차 등으로 인한 신뢰성도 낮다. 최근 대부분의 외국에서는 방사성 동위원소(RI)를 이용한 흙의 밀도/함수량 측정계기를 성토시공관리에 이용하고 있으나 국내에서는 이에 대한 기초연구의 부족 등의 이유로 건설분야에서의 RI계기 이용이 제한되어 있는 실정이다. 따라서 본 연구에서는 국내 토질 기술자들에게 RI계기를 소개하고 RI계기를 보다 효율적이고 안전하게 사용할 수 있도록 RI계기에 대한 기초연구를 실시하였다. 이를 위해 우선적으로 RI계기의 검증연구와 현장 적용성에 대한 검토를 실시한 후, 국내 토질에 적합한 교정식을 도출하였다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.537-537
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• 2013

Cyclotron-accelerated ion beams are used for various researches, such as nuclear physics, nuclear chemistry, biotechnology, and material sciences including radio-isotope production. Recently considerable applications are asked to the cyclotron development undertaken to meet user requirements of various ions'energies, intensities, and their pulsed beams. For instance, a cocktail beam acceleration technique rapidly changing the ion species and energies was developed to irradiating integrated circuit chips. Also a chopping system in a cyclotron injection line is considered for producing a pulsed ion beam with a relatively long period compared with that generated by the resonance frequency. For the research in neutron time-of-flight measurement, a single-pulsed beam with a repetition interval of the order of mili-seconds or longer is necessary to have a good resolution and to remove background events. In this paper a feasibility of pulsed beam with an external ion source is simulated by adopting a combination system of a chopper accompanying with a bunching stage in the injection line and an additional chopper after the exit of the cyclotron in order to produce beam pulses with a range of $1{\mu}s{\sim}1ms$ periods from a resonance RF cycle. The pulseperiod will be adjusted by chopping the number of beam bunches from the injected pulses in the injection line. However, the longer pulses will have reduced number of beam pulses and sacrificed beam currents. Because the beam users need an intense single pulsed beam, a careful tuning of the acceleration phase and a high-intense external ion source are necessary to achieve an intense single-pulsed beam from the cyclotron. It is essential to strictly match the acceleration phase of injected beams in the central region of the cyclotron to improve its efficiency. An effect of space charge at each pulse from the ion source will be also considered.

• 자연과학논문집
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• 제14권1호
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• pp.39-50
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• 2004

박테리오 파아지 T7 RNA 중합효소는 다른 RNA 중합효소와 비교하여 볼 때 보조인자 없이 전사를 진행하는 하나의 subunit로 구성된 RNA 중합효소이다. 전사 진행 단계 중에서 T7 RNA 중합효소의 전사연장을 연구하기 위해 biotin이 결합된 DNA 주형을 streptavidin bead로 고정시킴으로서 T7 RNA 중합효소의 진행과정을 관찰할 수 있었고, 이러한 기작을 이용하여 일련의 활성을 가지는 가장 안정한 전사연장복합체들을 얻을 수 있었다. 전사 연장체들은 16번 염기 위치로부터 18번 염기의 위치까지 방사선 동위원소가 표지되어 있으며 이들 표지된 전사연장복합체들은 단계별로 합성하여 22-40개 핵산잔기들이 합성된 전사연장복합체들을 얻을 수 있었다. 이와 같은 전사연장복합체들을 PTH 전사종결 부위가 있는 주형으로 사용하여 야생형 및 R173C 돌연변이 RNA 중합효소를 이용하여 전사연장복합체를 제조하여 비교한 결과 PTH 전사종결에 둔감한 R173C 돌연변이 중합효소의 경우 야생형에 비해 PTH 전사종결부위를 지난 위치에서도 전사연장복합체가 생성되었다.