• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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• pp.151-151
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• 2012

A new plasma process, i.e., the combination of PIII&D and HIPIMS, was developed to implant non-gaseous ions into materials surface. HIPIMS is a special mode of operation of pulsed-DC magnetron sputtering, in which high pulsed DC power exceeding ~1 kW/$cm^2$ of its peak power density is applied to the magnetron sputtering target while the average power density remains manageable to the cooling capacity of the equipment by using a very small duty ratio of operation. Due to the high peak power density applied to the sputtering target, a large fraction of sputtered atoms is ionized. If the negative high voltage pulse applied to the sample stage in PIII&D system is synchronized with the pulsed plasma of sputtered target material by HIPIMS operation, the implantation of non-gaseous ions can be successfully accomplished. The new process has great advantage that thin film deposition and non-gaseous ion implantation along with in-situ film modification can be achieved in a single plasma chamber. Even broader application areas of PIII&D technology are believed to be envisaged by this newly developed process. In one application of non-gaseous plasma immersion ion implantation, Ge ions were implanted into SiO2 thin film at 60 keV to form Ge quantum dots embedded in SiO2 dielectric material. The crystalline Ge quantum dots were shown to be 5~10 nm in size and well dispersed in SiO2 matrix. In another application, Ag ions were implanted into SS-304 substrate to endow the anti-microbial property of the surface. Yet another bio-application was Mg ion implantation into Ti to improve its osteointegration property for bone implants. Catalyst is another promising application field of nongaseous plasma immersion ion implantation because ion implantation results in atomically dispersed catalytic agents with high surface to volume ratio. Pt ions were implanted into the surface of Al2O3 catalytic supporter and its H2 generation property was measured for DME reforming catalyst. In this talk, a newly developed, non-gaseous plasma immersion ion implantation technique and its applications would be shown and discussed.

• Bulletin of the Korean Chemical Society
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• 제34권6호
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• pp.1684-1688
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• 2013

A rapid and sensitive method for determining usnic acid of Lethariella cladonioides in rat was established using high performance liquid chromatography (HPLC) quadrupole time-of-flight (QTOF) tandem mass (MS/MS). Rat plasma was pretreated by mixture of acetonitrile and chloroform to precipitate plasma proteins. Chromatographic separation was achieved on a column ($50{\times}2.1$ mm, $5{\mu}m$) with a mobile phase consisting of water (containing $5{\times}10^{-3}$ M ammonium formate, pH was adjusted to 3.0 with formic acid) and acetonitrile (20:80, v/v) at a flow rate of 0.3 mL/min. A tandem mass spectrometric detection with an electrospray ionization (ESI) interface was conducted via collision induced dissociation (CID) under negative ionization mode. The MS/MS transitions monitored were m/z 343.0448 ${\rightarrow}$ m/z 313.2017 for usnic acid and m/z 153.1024 ${\rightarrow}$ m/z 136.2136 for protocatechuic acid (internal standard). The linear range was calculated to be 2.0-160.0 ng/mL with a detection limit of 3.0 pg/mL. The inter- and intra-day accuracy and precision were within ${\pm}7.0%$. Pharmacokinetic study showed that the apartment of usnic acid in vivo confirmed to be a two compartment open model. The method was fully valid and will probably be an alternative for pharmacokinetic study of usnic acid.

• 한국자기공명학회논문지
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• 제4권1호
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• pp.19-28
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• 2000

Authors evaluated alterations of observable metabolite ratios between the cerebral lesion and the contralateral region related to the clinical symptomatic side in levodopa-treated Parkinson's disease (PD) and investigated correlation between age in patients with PD and metabolite ratios of the lesion. Patients with levodopa-treated PD (n = 54) and age-matched normal controls (n = 15) underwent magnetic resonance spectroscopy (MRS) examinations using a stimulated echo acquisition mode (STEAM) pulse sequence that provided 2$\times$2$\times$2 cm3 volume of interest in the selected regions of substantia nigra (SN) and putamed-globus pallidus (PG). To evaluate dependence of metabolite ratios on age, we divided into two groups (i.e., younger and older age). We quantitatively measured N-acetylaspartate (NAA), creatine (Cr), choline-containing compounds (Cho), inositols (Ins), and the sum of glutamate (Glx) and GABA levels and obtained proton metabolite ratios relative to Cr using a Marquart algorithm. Compared with the contralateral region, a significant neuronal laterality of the NAA/Cr ratio in the lesion of SN related to the clinical symptomatic side was established (P = 0.01), but was not established in the lesion of PG (P = 0.24). Also, Cho/Cr ratio tended toward significance in the lesion of SN (P = 0.07) and was statistically significant in the lesion of PG(P = 0.01). Compared with that in the younger age group, NAA/Cr ratio in the older age was decreased in the lesion of SN (P = 0.02), while NAA/Cr ratio was not statistically significant in the lesion of PG ( P = 0.21). Significant metabolic alterations of NAA/Cr and Cho/Cr ratios might be closely related with functional changes of neuropathological process in SN and PG of levodopa treated PD and could be a valuable finding for evaluation of the PD. A trend of NAA/Cr reduction, being statistically significant in older patients, could be indicative of more pronounced neuronal damage in the SN of the progressive PD.

• 대한핵의학회지
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• 제25권2호
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• pp.286-293
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• 1991

$^{123}I$, which is applied for the thyroid and other in vivo kinetic study, has a special role in life sciences. The 159 KeV $\gamma-ray$ from $^{123}I$ is almost ideally appropriate for the current imaging instrumentation. Its decay mode (electron capture) and short half-life (13.3 hr) reduced the burden of radiation dose to the patients, and its chemical property makes it easy to synthesize the labelling compounds. In this experiment, the production of $^{123}I$ via the nuclear reaction $^{124}Te(p,2n)^{123}I$ with 28 MeV protons was sutdied. $TeO_2$ is used as a target material, because it has good physical properties. The target was prepared with $TeO_2$ powder and was molten into a ellipsoidal cavity (a=14 mm, b=10 mm, $270.8mg/cm^2$ thick) of pure platinum. The irradiation was carried out in the external proton beam with incident energies range from 28 MeV to 22 MeV, and current was $30{\mu}A$. The loss of $TeO_2$ target was significantly reduced by using $4\pi-cooling$ system in irradiation. The dry distillation method was adopted for the separation of $^{123}I$ from irradiated target, and when it was kept 5 minutes at $780^{\circ}C$, its result was quantitative. The loss of the target material $(TeO_2)$ was below 0.2% for each production run and $^{123}I$ from the dry distillation apparatus was captured with 0.01 N NaOH in $Na^{123}I$ form, then the pH of the solution was adjusted to $7.5\sim9.0$ with HC1/NaOH. The $Na^{123}I$ solution was passed through $0.2{\mu}m$ membrane filter, and sterilized under high pressure and temperature for 30 minutes. The production of $^{123}I$ is acceptable for clinical application based on the quality of USP XXI.

• 한국잡초학회지
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• 제17권2호
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• pp.192-198
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• 1997

벼와 피간(間)의 속간(屬間) 선택성(選擇性)을 구명(究明)하기 위하여 제초제(除草劑) cyhalofop-BE에 대(對)한 Acetyl-CoA carboxylase의 효소활성(酵素活性), 지방산(脂肪酸) 및 생합성(生合成) 단백질(蛋白質) 패턴에 미치는 영향(影響)을 시험(試驗)한 결과(結果)를 요약(要約)하면 다음과 같다. 1. ACCase을 저해하는 농도는 피가 1-2ppm 농도(濃度)의 낮은 수준(水準)이었고 벼는 10배(倍) 이상(以上)의 높은 농도(濃度)에서 저해(沮害)되었다. 2 벼 및 피의 지방산(脂肪酸) 생합성(生合成)에 관여(關與)하는 ACCase의 효소(酵素)가 저해(沮害)되어 피는 포화지방산(飽和脂肪酸)인 palmitic acid가 무처리(無處理)에 비(比)해 61%, 불포화지방산(不飽和脂肪酸)인 linoleic acid가 54%, linolenic acid는 41%가 정도(程度) 억제(抑制)되었으나 벼는 무처리(無處理)와 큰 차이(差異)를 보이지 않았다. 3. 피는 29KD와 36KD사이 및 36KD 와 45KD사이의 spot가 소멸(消滅)되어 단백질(蛋白質)패턴에 영향(影響)이 있었다.

• Progress in Superconductivity
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• 제5권1호
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• pp.50-54
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• 2003

We have fabricated $∂^2$$B_{z}$ /$∂x^2$ type planar gradiometers and studied their properties in operation under various field conditions. $YBa_2$$Cu_3$$O_{7}$ film was deposited on $SrTiO_3$ (100) substrate by a pulsed laser deposition (PLD) system and patterned into a device by the photolithography with ion milling technique. The device consists of 3 pickup loops designed symmetrically Inner dimension and the width of the square side loops are 3.6 mm and 1.2 mm, respectively, and the corresponding dimensions of the center loop are 2.0 mm and 1.13 mm. The length of baseline gradiometer is 5.8 mm. Step-edge junction width is 3.0 $\mu\textrm{m}$ and the hole size of the SQUID loop is 3 $\mu\textrm{m}$ ${\times}$ 52 $\mu\textrm{m}$. The SQUID inductance is estimated to be 35 pH. The device was formed on a 20 mm ${\times}$ 10 mm substrate. We have tested the behavior of the device in various field conditions. The unshielded gradiometer was stable under extremely hostile conditions on a laboratory bench. Noise level 0.45 pT/$\textrm{cm}^2$/(equation omitted)Hz and 0.84 pT/$\textrm{cm}^2$/(equation omitted)Hz at 1 Hz for the shielded and the unshielded cases, which correspond to equivalent field noises of 150 fT/(equation omitted)Hz and 280 fT/(equation omitted)Hz, respectively. In spite of the short baseline of 5.8 mm, the high common-mode-rejection-ratio of the gradiometer, $10^3$, allowed us to successfully record magnetocardiogram of a human subject, which demonstrates the feasibility of the design in biomagnetic studies.

• 공업화학
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• 제9권7호
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• pp.1030-1035
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• 1998

본 연구에서는 시판용 99.8% 금속알루미늄을 황산전해액에서 정전류 방식에 막을 제조하는 실험을 하였다. 반응온도 $20^{\circ}C$에서 $150C/cm^2$의 전기량으로 양극산화를 함에 있어 전해질에 의한 막의 용해작용을 저하시킬 목적으로 전해질 속에 알루미늄 이온의 형태로 존재할 수 있는 $Al_2(SO_4)_3$, $AlPO_4$, $Al(NO_3)_3$를 첨가제로 사용하였다. 황산 전해질의 농도를 5, 10, 15, 20 wt%로 전류밀도를 10, 20, 30, 40, $50mA/cm^2$로 조절하여 양극산화를 할 때 각 전해조에 첨가제를 각각 5, 10, 15, 20 g/L를 용해시켜 막제조에 따른 첨가제의 종류 및 양의 영향을 고찰하고자 하였다. 전해질과 공통이온으로 존재하는 $Al_2(SO_4)_3$를 첨가제로 사용하여 양극산화를 하여 막 표면에 손상이 없는 다공성 알루미나 막을 얻을 수 있었으며, 그 외 첨가제에서는 각 실험조건에서 막의 표면이 심하게 손상되어 첨가제로서 효과를 얻을 수 없었다. 한편, 동일한 전해질의 농도, 전류밀도 조건에서 $Al_2(SO_4)_3$의 첨가량에 따른 세공직경의 변화는 거의 없는 것으로 나타났다.

• Earthquakes and Structures
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• 제12권6호
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• pp.603-617
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• 2017

This paper presents investigation into the behavior of beam-column joints, with the joint region concrete being replaced by steel fiber reinforced concrete (SFRC) and by ultra-high performance concrete (UHPC). A total of ten beam-column joint specimens (BCJ) were tested experimentally to failure under monotonic and cyclic loading, with the beam section being subjected to flexural loading and the column to combined flexural and axial loading. The joint region essentially transferred shear and axial stresses as received from the column. Steel fiber reinforced concrete (SFRC) and ultra-high performance concrete (UHPC) were used as an innovative construction and/or strengthening scheme for some of the BCJ specimens. The reinforced concrete specimens were reinforced with longitudinal steel rebar, 18 mm, and some specimens were reinforced with an additional two ties in the joint region. The results showed that using SFRC and UHPC as a replacement concrete for the BCJ improved the joint shear strength and the load carrying capacity of the hybrid specimens. The mode of failure was also converted from a non-desirable joint shear failure to a preferred beam flexural failure. The effect of the ties in the SFRC and UHPC joint regions could not be observed due to the beam flexural failure. Several models were used in estimating the joint shear strength for different BCJ specimens. The results showed that the existing models yielded wide-ranging values. A new concept to take into account the influence of column axial load on the shear strength of beam-column joints is also presented, which demonstrates that the recommended values for concrete tensile strength for determination of joint shear strength need to be amended for joints subject to moderate to high axial loads. Furthermore, finite element model (FEM) simulation to predict the behaviour of the hybrid BCJ specimens was also carried out in an ABAQUS environment. The result of the FEM modelling showed good agreement with experimental results.

• 보존과학회지
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• 제35권6호
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• pp.701-708
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• 2019

아교는 짐승의 가죽이나 뼈를 정제하여 제조한 천연접착제로 목재, 종이 등의 공예나 단청 또는 그림 채색 시의 교착제로서 다방면에 사용되고 있다. 아교의 사용 조건은 다양하나 전처리 및 측정조건에 따른 아교 특성을 평가하는 방법이 정형화되어있지 않아 아교 생산 및 사용에 있어서 정확한 품질평가가 어려운 실정이다. 이에 본 연구에서는 시중에 판매되고 있는 아교 및 젤라틴을 대상으로 팽윤과 온도, 농도 등의 조건을 세분화하여 특성 평가를 실시하였다. 연구 결과, 물리적 특성 평가는 아교를 23℃, 6시간 동안 팽윤한 뒤 점도 측정 시에 안정적인 결과 값을 나타냈으며 시판아교 12종 대상으로 점도 최솟값이 12.67 cP, 최댓값은 29.43 cP으로 측정되었다. 광학적 특성 평가에서는 10% 농도의 아교를 분광측색계의 반사모드로 측정 시 경향성 및 정제된 값을 가짐을 확인하였다. 분말아교는 중반대의 명도와 상중반대의 채도를 가지며 막대아교는 상대적으로 밝기가 낮으며 중반대의 채도를 가진 것으로 확인되었다. 본 연구를 통해 아교를 사용하는 작업자 또는 연구자에게 시판아교의 특성에 대한 기초자료를 제공하고, 향후 아교 특성을 평가하기 위한 평가기준 및 방법을 제시할 수 있을 것으로 기대한다.

• 한국잡초학회지
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• 제14권4호
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• pp.280-290
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• 1994

작물(作物)과 잡초(雜草)에서 Oxyfluorfen과 Chlormethoxynil에 대한 선택성(選擇性)과 살초력(殺草力)을 비교(比較)하고자 발아실험(發芽實驗), 수경재배실험(水耕栽培實驗), 두가지 토양(土壤)에서의 발아전(發芽前) 토양처리실험(土壤處理實驗)을 실시(實施)하였으며, 처리부위(處理部位)와 시간(時間)을 다르게 하였을 때의 초종간(草種間) 흡수(吸收) 및 이행(移行)을 조사하고자 $^{14}C$-oxyfluorfen을 이용(利用)한 흡수이행실험(吸收移行實驗)을 실시(實施)하였다. 1. 발아실험(發芽實驗), 수경재배실험(水耕栽培實驗), 발아전(發芽前) 토양처리실험(土壤處理實驗)을 통하여 볼 때 벼, 옥수수에서는 공시제초제(供試除草劑) 농도(濃度)가 증가(增加)되면서 약간 생장(生長)이 억제(抑制)되는 경향(傾向)을 나타냈으나 감수성(感受性) 초종(草種)인 참소리쟁이, 바랭이에서는 농도(濃度)가 높아짐에 따라 살초력(殺草力)이 증대(增大)되어 생장억제(生長抑制)가 심하였으며 전반적(全般的)으로 Oxytluorfen처리(處理)는 Chlormethoxynil처리(處理)보다 생장억제(生長抑制)가 심하였다. 2. 발아기간(發芽期間)동안의 생육억제(生育抑制) 효과(效果)를 나타낸 것을 보면 발아과정(發芽過程) 때보다 발아후(發芽後) 생육과정(生育過程)에서 많은 것으로 사료(思料)되며, 벼와 옥수수에서 가장 둔감(鈍感)한 반응(反應)을, 피에서는 비교적 둔감(鈍感)한 반응(反應)을, 참소리쟁이와 바랭이에서는 가장 민감(敏感)한 반응(反應)을 나타내었다. 3. 수경재배실험(水耕栽培實驗) 결과(結果), 2엽기(葉期)에서의 처리(處理)가 4엽기(葉期)에서의 처리(處理)보다 생장억제(生長抑制)가 더 심하게 나타났으며 지상부(地上部)보다 지하부(地下部)가 많은 생장억제(生長抑制)를 나타내었다. 4. 발아전(發芽前) 토양처리실험(土壤處理實驗) 결과(結果), 유기물(有機物), C.E.C. 및 점토성분(粘土成分)이 적은 사양토(砂壤土)에서 생장억제(生長抑制)가 심하였으며 초종간(草種間)에는 참소리쟁이와 바랭이에서 많이 나타났다. 5. $^{14}C$-oxytluorfen의 흡수(吸收)는 작물(作物)과 잡초(雜草)에서 모두 잘 되였으나 이행은 모든 초종(草種)에서 거의 되지 않는 경향이었으나 시간(時間)이 경과(經過)함에 따라 감수성(感受性) 초종(草種)인 참소리쟁이와 바랭이에서 흡수량(吸收量)이 많아졌으며 작물(作物)과 잡초간(雜草間) 선택성(選擇性)은 주로 흡수(吸收)된 양(量)에 따라 결정된다고 생각한다.