• Bulletin of the Korean Chemical Society
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• v.35 no.10
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• pp.2995-3000
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• 2014

A sensitive concentration method utilising modified gas-purge microsyringe extraction (GP-MSE) was developed. Concentration (reduction in volume) to a microlitre volume was achieved. PAHs were utilised as semivolatile analytes to optimise the various parameters that affect the concentration efficiency. The injection rate and temperature were the key factors that affected the concentration efficiency. An efficient concentration (75.0-96.1%) of PAHs was obtained under the optimised conditions. The method exhibited good reproducibility (RSD values that ranged from 1.5 to 9.0%). The GP-MSE concentration method enhances the volume reduction (concentration factor), leading to a low method detection limit ($0.5-15ngL^{-1}$). Furthermore, this method offers the advantage of small-volume sampling, enabling even the detection of diurnal hourly changes in the concentration of PAHs in ambient air. Utilising this method in combination with GC-MS, the diurnal hourly flux of PAHs from the gas phase of ambient air was measured. Indeed, the proposed technique is a simple, fast, low-cost and environmentally friendly.

• Bulletin of the Korean Chemical Society
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• v.35 no.4
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• pp.1195-1201
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• 2014

Atomic layer deposition (ALD) of $TiO_2$ thin film from $TiCl_4$ and $H_2O$ has been intensively studied since the invention of ALD method to grow thin films via chemical adsorptions of two precursors. However the role of HCl which is a gaseous byproduct in ALD chemistry for $TiO_2$ growth is still intriguing in terms of the growth mechanism. In order to investigate the role of HCl in $TiO_2$ ALD, HCl pulse and its purging steps are inserted in a typical sequence of $TiCl_4$ pulse-purge-$H_2O$ pulse-purge. When they are inserted after the first-half reaction (chemisorption of $TiCl_4$), the grown thickness of $TiO_2$ becomes thinner or thicker at lower or higher growth temperatures than $300^{\circ}C$, respectively. However the insertion after the second-half reaction (chemisorption of $H_2O$) results in severely reduced thicknesses in all growth temperatures. By using the result, we explain the growth mechanism and the role of HCl in $TiO_2$ ALD.

• Journal of the Semiconductor & Display Technology
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• v.22 no.1
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• pp.23-27
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• 2023

Organic light-emitting diode(OLED) is very thin organic films which are hundreds of nanometers. Unlike bottom-emission OLED(BEOLED), top-emission OLED(TEOLED) emits light out the front, opaque moisture absorbents or metal foils can't be used to prevent moisture and oxygen. And it is difficult to have flexible characteristics with glass encapsulation, so thin film encapsulation which can compensate for those two disadvantages is mainly used. In this study, Al₂O₃ thin films by atomic layer deposition(ALD) were examined by changing the argon gas purge flow rate and we applied this Al₂O₃ thin films to the encapsulation of TEOLED. Ag / ITO / N,N'-Di-[(1-naphthyl)-N,N'-diphenyl]-1,1'-biphenyl-4,4'-diamine / tris-(8-hydroxyquinoline) aluminum/ LiF / Mg:Ag (1:9) were used to fabricate OLED device. The characteristics such as brightness, current density, and power efficiency are compared. And it was confirmed that with a thickness of 40 nm Al₂O₃ thin film encapsulation process did not affect OLED properties. And it was enough to maintain a proper OLED operation for about 9 hours.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.28-28
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• 2022

This paper presents the first genome assemblies of Philippine mangoes that provide valuable reference for varietal improvement and genomic studies on mango and related fruit crops. WE sequenced whole genomes of3 species, Mangifera odorata (Huani), Mangifera altissima (Paho), and Mangifera indica 'Carabao' (Sweet Elena). 'Carabao' is the major export variety of the Philippines; Paho is identified as vulnerable by the IUCN Red List of Threatened Species; Huani has fruit sap acrid which is the primary defense mechanism against insects and birds. We used Falcon, a diploid aware -de novo assembler to assemble SMRT generated long-read sequences. Falcon-unzip was employed to phase the output assembly producing larger contig sets (primary contigs) and shorter contigs corresponding to haplotypes (haplotigs). Assembly statistics were generated by comparing the assembly to a reference genome, Tommy Atkins, using Quality Assessment Tool (QUAST). Moreover, the extent of duplication and completeness of gene content was measured using Benchmarking Universal Single-Copy Orthologs (BUSCO). Draft assemblies with high duplications were processed using Purge Haplotigs and Purge Dups to lessen duplications with minimal impact on genome completeness. De novo assemblies of Huani, Paho and 'Carabao' were then generated with primary contig sizes of 463.64 Mb, 508.95 Mb and 401.51 Mb respectively. These draft assemblies of Huani, Paho and 'Carabao' showed 96.90%, 95.17% and 99.07% complete BUSCOs respectively which is comparable to 'Tommy Atkins' genome (98.6%). Using two mango transcriptome data (pooled RNA-seq from different mango varieties and tissues), 91-96% or 24-30 million reads were successfully mapped back for each generated assembly indicating high degree of completeness. The results obtained demonstrated the highly contiguous, phased, and near complete genome assembly of three Philippine mango species for structural and functional annotation of gene units, especially those with economic importance.

• The Journal of Korean Medicine
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• v.28 no.3 s.71
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• pp.37-44
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• 2007

Objectives : The objectives of this study lie in theoretical establishment of Bopyeo-tang for treating asthenic syndrome of the lung through analyzing the component medicines and combination principles of Hyeongok's Bopyeo-tang, and furthermore, maximizing the clinical effectiveness of Bopyeo-tang. Methods : This study analyzed the component medicines and combination principles of Hyeongok's Bopyeo-tang based on the theory for properties and tastes of herbal medicines from the ${\ulcorner}$Yellow Emperor's Canon of Internal Medicine${\lrcorner}$, the theory for principal herbal medicine, assistant herbal medicine, adjuvant herbal medicine, dispatcher herbal medicine, and the five elements doctrine. Hyeongok's Bopyeo-tang is an unusual prescription, composed of 7 kinds of ingredients. Results : There are three methods for curing asthenic syndrome of the lung according to the five elements doctrine: invigorating the lung, invigorating the spleen and purging the heart. There are two available methods to invigorate the lung, taste and property invigoration, according to the theory for properties and tastes of herbal medicines. They each imply the sour taste and the cool property invigorate the lung. In the case of taste invigoration, two herbal medicines with sour taste, Sarcucarpium Corni and Fructus Schisandrae, are combined into the principal and assistant herbal medicine, respectively. For property invigoration, two herbal medicines with the cool property, Colla Corii Asini and Radix Ophiopogonis, are combined into adjuvant herbal medicines. There are likewise two methods to invigorate the spleen, including taste and property invigoration according to the theory for properties and tastes of herbal medicines. They each mean the sweet taste and the warm property invigorate the spleen. Therefore, it is important to use sweet herbal medicines for taste invigoration and warm ones for property invigoration. Both sweet and warm herbal medicines, Radix Ginseng and Rhizoma Atractylodis Macrocephalae, are combined into adjuvant herbal medicines. Lastly, there are two methods to purge the heart, which include taste and property purgation according to the theory for properties and tastes of herbal medicines. Taste purgation means to purge the heart with sweet taste and property purgation to purge the heart with cold property. Therefore, it is important to use sweet herbal medicines for taste purgation and cold ones for property purgation. Both sweet and cold herbal medicines, Colla Corii Asini and Radix Ophiopogonis, were combined to purge the heart and invigorate the lung. In addition, Radix Glycyrrhizae Praeparata is added as a dispatcher herbal medicine, harmonizing all the other herbal medicines comprising the formula. Conclusions : First, to treat asthenic syndrome of the lung, the methods of invigorating the lung and the spleen and purging the heart should be used according to the five elements doctrine. Secondly, herbal medicines appropriate for those treatment methods should be chosen according to the theory for properties and tastes of herbal medicine and thirdly, the combination of those herbal medicines should be carried out according to the theory for principal herbal medicine, assistant herbal medicine, adjuvant herbal medicine, and dispatcher herbal medicine. As a good example, Hyeongok's Bopyeo-tang is combined according to the above theories. In conclusion, this formula was created by applying the theory of properties and tastes of herbal medicines.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.378-379
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• 2012

ITO 만큼 높은 전도성과 광학적 투과성을 갖는 Al-doped ZnO (AZO) 박막을 DC-Pulse magnetron sputtering을 이용하여 40 nm 두께로 증착 후 리소그라피 공정을 통해 $30{\mu}m$ 간격으로 패터닝 하였다. 간격 30 ${\mu}m$로 배열된 AZO를 촉매층으로 하는 수열합성법을 리사이클 공정을 반복하여 수행하여 ZnO 나노선을 성장시켰다. 이와 같이 AZO 전극 사이에 길이 $30{\mu}m$의 ZnO 나노선이 래터럴 구조로 연결된 소자의 $NH_3$ 가스감지 특성을 조사하였다. 합성된 나노선의 전기적, 광학적, 구조적인 특성을 분석하여 높은 가스 감지도를 예상할 수 있는 특성을 확인하였다. 제작된 가스센서를 진공 챔버에 설치 후 양 전극간에 동작전압(Operating voltage)을 1 V로 인가하여 고정한 후에 $NH_3$를 주입(Injection)과 퍼지(Purge)를 반복하며 그 주입량(10 ppm, 20 ppm, 40 ppm, 60 ppm)에 변화를 주었고, 그에 따른 전류변화를 관찰하여 $NH_3$ 가스감지특성을 평가하였다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.13-13
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• 2009

본 연구는 MLCC 구성성분의 증발/비등에 의한 저분자물질의 제거가 bar 수축에 미치는 영향도를 평가하기 위해, 압착 bar에서 발생하는 고농도의 out gas를 정량하기 위한 최적 system을 구축하고자 하였다. gas 포집에 범용적으로 사용하는 Purge & Trap sampler 대신 Heating block를 사용하여 gas를 발생시키고 동시에 solvent에 용해시킴으로써 고농도의 시료가 희석될 수 있는 전처리 장치를 디자인하였다. 그 결과 고농도 gas 주입에 의한 장비오염과 peak saturation 문제가 해결되었고, gas phase의 시료를 liquid phase로 상전이 시켜 autosampler를 이용한 정확한 량의 시료 주입이 가능하였다. System의 Gage Linearity와 Bias는 각각 1.7%와 1.3%로 개선이 필요없는 수준의 정확도를 가졌다.

• Journal of Korean Society for Atmospheric Environment
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• v.9 no.1
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• pp.101-106
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• 1993

In order to separate the Freon-12 and air mixture$(CF_2Cl_2/Air=0.1/99.9 vol.%)$ by pressure swing adsorption (PSA), the breakthrough curve was experimentally observed in a fixed bed adsorption column. A single adsorber was packed with various adsorbents such as, the activated carbon(S-AC, W-AC) and the molecular sieve(MS-5A, MS-13X). The order of appearance of breakthrough curve is MS-5A > MS-13X > W-AC > S-AC. The activated carbon was found to be more effective adsorbent for separating Freon-12 from the mixture than the molecular sieve was. From the experimental data obtained by the separation of Freon-12 gas out of the air stream in the steady-state PSA process cycle, whose size is the same one of column used for the breakthrough curve observation, it has been confirmed that Freon-rich gas could be obtained from the purge step of PSA and Freon-free air could be obtained from the adsorption step of PSA cycle.

• Preventive Nutrition and Food Science
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• v.3 no.3
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• pp.230-233
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• 1998

Acetic acid producing bacteria were isolated from deastringent persimmon vinegar and the major bacterium was identified using morphological and biochemical tests. Acetobacter sp. AH-1 was motile, gram negative rod with catalase positive and oxidase negative. The strain can grow up to 5 % ethanol and 2% NaCl as well as 25% glucose. Optimum temperature and pH for growth were 3$0^{\circ}C$ and 5.0, respectively. Volatile constituents of persimmon vinegar were analyzed by purge and trap sampling . Acetic acid adn alcohol were the largest volatile compounds quantitiatively in persimmon vinegar. Among alcohols, 20methyl-1-propanol, isoamyl alcohol and amyl alcohol were detected. Isovaleradehyde and benzaldehyde for aldehyde, isoamyl acteate, ethyl formate, propyl aceetate, and ethyl acetate for esters were likely to contribute to persimmon vivegar flavor.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.11a
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• pp.164-164
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• 2003

UV 발광소자 재료로서 유망한 ZnO film을 ALE법으로 증착하고 photoluminescence특성을 조사하였다. Zn소스로서 DEZn(Diethylzinc)를, 산소 소스로서 DI water를 사용하였고 $N_2$ gas로서 챔버내에 주입된 소스물질을 purge하였다. ALE 공정온도 범위인 17$0^{\circ}C$와 CVD 반응온도 범위인 40$0^{\circ}C$로 ZnO 박막을 증착하고 이 시편을 산소 분위기에서 600-100$0^{\circ}C$의 온도로 1시간 동안 열처리하였다. 그리고 He-Cd laser를 사용하여 photoluminescence를 측정하였다. 17$0^{\circ}C$와 40$0^{\circ}C$ 에서 증착된 시편 모두 as-grown 상태에서는 거의 발광특성을 나타내지 못하였으나 후열처리를 거치면서 발광특성을 나타내었고 열처리 온도가 높을수록 발광강도가 증가하였다. 40$0^{\circ}C$에서의 증착된 시편의 경우는CVD반응이 발생하여 Zn-Zn결합이 많이 생성되어 열처리 온도가 증가하여도 발광강도가 약하였고 가시광 영역의 발광 또한 크게 증가하였으며 17$0^{\circ}C$에서 증착된 시편의 경우는 열처리 온도가 증가할수록 UV영역의 발광강도만이 크게 증가하였으며 가시광 영역의 발광은 거의 증가하지 않았다.