Reaction of Gas-Phase Bromine Atom with Chemisorbed Hydrogen Atoms on a Silicon(100)-(2${\times}$1) Surface

이종백,장경순,문경환,김유항,Lee, Jong Baek,Jang, Gyeong Sun,Mun, Gyeong Hwan,Kim, Yu Hang Korean Chemical Society 2001 Bulletin of the Korean Chemical Society Vol.22 No.8

The reaction of gas-phase atomic bromine with highly covered chemisorbed hydrogen atoms on a silicon surface is studied by use of the classical trajectory approach. It is found that the major reaction is the formation of HBr(g), and it proceeds th rough two modes, that is, direct Eley-Rideal and hot-atom mechanism. The HBr formation reaction takes place on a picosecond time scale with most of the reaction exothermicity depositing in the product vibration and translation. The adsorption of Br(g) on the surface is the second most efficient reaction pathway. The total reaction cross sections are $2.53{\AA}2$ for the HBr formation and $2.32{\AA}2$ for the adsorption of Br(g) at gas temperature 1500 K and surface temperature 300 K.

방향족 고리를 갖는 액정폴리우레탄의 합성 및 특성

이종백 ( Jong Baek Lee ) 한국고무학회 2013 엘라스토머 및 콤포지트 Vol.48 No.2

메소겐(Mesogen) 단위가 포함되어 있지 않는 para- 형태의 1,4-phenylene diisocyanate (1,4-PDI)와 2,6-bis(ω-hydroxypentoxy)naphthalene (BHN5) 또는 1,4-bis(ω-hydroxypentoxy)benzene (BHB5)을 단일과 공중합폴리우레탄을 부가중합에 의해 합성하였다. 모든 공중합폴리우레탄에서는 전단변형의 측정에서 단방성액정상을 나타내었다. 예를 들면, 고유점도가 [∩]=0.32 dL/g인 폴리우레탄 Poly(50/50, mol%)은 223℃∼211℃에서 냉각 시 액정성을 나타내었다. 그러나 두 개의 단일폴리우레탄에서는 DSC (Differental Scanning calorimeter) 측정 및 편광현미경 관찰에서도 액정상을 전혀 관찰 할 수 없었다. 합성된 폴리우레탄의 액정성은 시차주사열량분석기, 편광현미경과 X-ray에 의해 확인하였다. Polyurethanes containing no mesogenic unit were prepared by polyaddition reaction of homo- and copolyurethanes based on para-type 1,4-phenylene diisocyanate (1,4-PDI), 2,6-bis(ω-hydroxypentoxy)naphthalene (BHN5) with 1,4-bis(ω-hydroxypentoxy)benzene (BHB5). All copolyurethanes showed monotropic liquid crystallinity, when measurements were performed under shearing. For example, a polyurethane Poly(50/50, mol%) with [∩]=0.32 dL/g exhibited liquid crystallinity in the temperature range from 223℃ to 211℃ in the cooling stage. In contrast, two homopolyurethanes exhibited no explicit mesomorphic behavior, which was observed by DSC (Differental Scanning calorimeter) and measurement and polarized microscopic observation. The mesomorphic behavior of synthesized polyurethane was identified and characterized by differential scanning calorimetry, polarized optical microscope and X-ray.

4,4`-Bis(3-hydroxypropoxy)Biphenyl와 Diisocyanate에 의한 열방성 액정폴리우레탄 합성

이종백 ( Jong Baek Lee ) 한국화학공학회 2010 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.48 No.5

운동선수를 위한 체중감량방법 고찰

이종백 ( Lee Jong-baek ) 제주대학교 체육진흥센터 2021 체육과학연구 Vol.27 No.-

The purpose of this study is to use as basic data so that athletes can lose weight safely and effectively as a study examining several literatures on effective weight loss of athletes. In general, athletes in weight classes are rapidly losing weight with extremely limited calories for the purpose of obtaining favorable conditions for their physique and physical strength. In several literatures, it is known that weight loss of 5% or more of an individual’s weight has an unfavorable effect on health and can negatively affect athletic performance. An effective weight loss plan must be established by predicting the body’s energy balance and weight loss, and extreme energy intake restrictions have a negative physiological effect. For proper weight loss for athletes, intake of protein and low energy density foods is recommended. In addition, a new method for managing weight and health using intestinal microbes has been proposed in the long term.

비페닐렌 메소겐단위를 포함한 4,4`-bis(ω-hydroxyalkoxy)biphenyl 의 합성 및 열적성질

이종백 ( Jong Baek Lee ) 한국공업화학회 2002 공업화학 Vol.13 No.7

화합물 4,4`-bis(ω-hydroxyalkoxy)biphenyls (BPm; m=3, 4, 5, 6, 7, 8, 9, 10, 11, 12)은 4,4`-dihydroxybiphenyl와 ω-halogenated alkanols를 반응시켜 합성하였다. IR 및 ^1H NMR 스펙트럼을 사용하여 합성된 BPm의 구조를 분석하였다. 이들의 열적 및 액정특성을 관찰하기 위해서 DSC 및 편광현미경을 사용한 결과, BPm은 모두 일정한 온도 영역에서 스멕틱 상의 액정성을 나타내었다. 또한 이러한 액정 화합물은 전형적인 짝수-홀수의 효과를 나타내었다. A series of 4,4`-bis(ω-hydroxyalkoxy)biphenyls (BPm; m=3, 4, 5, 6, 7, 8, 9, 10, 11, 12) was synthesized by the reaction of 4,4-dihydroxybiphenyl with ω-halogenated alkanols. The chemical structures of BPm were determined by lnfrared and ^1H NMR spectra. All these compounds exhibited a smectic liquid crystalline phase in a certain temperature range, which was determined by differential scanning calorimetry (DSC) and polarizing optical microscopy (POM). The liquid crystalline compounds also showed the typical even-odd effect.

요트청소년대표팀 선수들의 비대면 체력측정과 측정신뢰도 분석

이종백 ( Lee Jong-baek ) 제주대학교 체육진흥센터 2024 체육과학연구 Vol.30 No.0

The purpose of this study is to analyze the reliability of physical fitness measurements of online youth yacht athletes. For this purpose, a total of 24 people (15 men and 9 women) selected as youth national team players were divided into first and second measurements. Based on these results, reliability was analyzed through intraclass correlation coefficient analysis between the first and second measurements, and two-way ANOV A analysis was perfom1ed to analyze differences between gender and order. As a result, only sit up, repeated jump, and plank measurements showed statistically significant reliability(p<.0l). In the analysis of differences between gender and technique, there was a difference only in the correlation between gender and technique for push-ups(p<.0l), and for sit-ups, only differences were found according to gender(p<.0l). In the future, it is believed that follow-up research will be needed to increase the reliability of the study through research that analyzes both internal and external indicators.

새로운 형태의 액정폴리우레탄의 합성 및 특성

이종백 ( Jong Baek Lee ),이광현 ( Kwang Hyun Lee ),강병철 ( Byung Chul Kang ) 한국고무학회 2006 엘라스토머 및 콤포지트 Vol.41 No.2

비페닐기를 함유하는 새로운 형태의 액정성 폴리우레탄을 신규로 합성한 4,4`-Bis(9-hydroxynonoxy)biphenyl (BP9)와 2,6-tolylene diisocyanate, 2,5-tolylene diisocyanate, 2,4-tolylene, diisocyanate, 1,4-phenylene diisocyanate 및 hexamethylene diisocyanate의 중부가 반응에 의해 합성하였다. 단량체 BP9은 스멕틱상을 형성하였으며 1,4-PDI/BP9을 제외한 나머지 폴리우레탄에서는 모두 액정성을 나타내었다. 합성된 단량체와 중합체들의 구조는 적외선분광분석기 및 핵자기공명분석기를 사용하여 확인 하였으며, 그들의 열적 상전이 온도 및 안정성들은 시차주사 열량분석기와 편광현미경으로 조사하였다. A series of thermotropic polyurethanes containing biphenyl units was synthesized by polyaddition reaction of diisocyanates such as 2,6-tolylene diisocyanate, 2,5-tolylene diisocyanate, 2,4-tolylene diisocyanate, 1,4-phenylene diisocyanate, and hexamethylene diisocyanate with 4,4`-Bis(9-hydroxynonoxy)biphenyl (BP9). 4,4`-bis(9-hydroxynonoxy)biphenyl exhibited a smectic type mesophase. Mesophase was found for all synthesized liquid crystalline polyurethanes except 1,4-PDI/BP9 based polyurethane. Structures of the monomer and the corresponding polymers were identified using FT-IR and 1H-NMR spectroscopies. Their phase transition temperatures and thermal stability were also investigated by differential scanning calorimetry and optical polarizing microscopy.

Er과 Y을 첨가한 SrTiO₃:Al₁Pr 형광체의 발광특성

박창섭,이종백,유일,Park Chang-Sub,Lee Jong-Baek,You Il 한국전기전자재료학회 2006 전기전자재료학회논문지 Vol.19 No.10

[ $SrTiO_3:Al,Pr$ ] red phosphors doped with Y and Er were synthesized by solid state reaction method. The luminescence properties of $SrTiO_3:Al,Pr$ phosphors before and after doping were examined by photoluminescence. Efforts were paid to elucidate the cause of the increase of green luminescence in $(Sr_{0.95}Y_{0.05})TiO_3:Pr,Er\;and\;(Sr_{0.95}Y_{0.05})TiO_3:Pr,Al$ phosphors. The enhanced green luminescence was interpreted by the energy transfer between $Er^{3+}\;and\;Pr^{3+}$ ions, and the change of bandgap in the $(Sr_{0.95}Y_{0.05})TiO_3:Pr$ phosphors.

과학 영재 교육 프로그램에 대한 분석 연구 I - 물리 영역을 중심으로 -

박종원,이종백,오원근,박종석,Park, Jong-Won,Lee, Jong-Baek,O, Won-Geun,Park, Jong-Seok 한국영재학회 2000 영재교육연구 Vol.10 No.1

Application in Ultrafiltration and Reverse Osmosis Module Set with Acrylic Wastewater Pretreated by Coagulation-Filtration-Neutralization Process

이광현,강병철,이종백,Lee, Kwang-Hyun,Kang, Byung-Chul,Lee, Jong-Baek The Membrane Society of Korea 2008 멤브레인 Vol.18 No.1

After membrane fouling factors in acrylic wastewater were minimized by pretreatment process accompanied with coagulation-filtration-neutralization, it was utilized in UF/RO process. After composing of ultrafiltration and reverse osmosis module set according to types and kinds of membrane, the separation characteristics were examined with the variation temperature and pressure using pretreated acrylic wastewater by membrane module sets. It was found that permeate flux of UF module in module set 4 was about two${\sim}$three times larger than that of UF module in module set 1. Final quantity of permeate from the module set 2 and module set 3 combined with tubular module was shown very good result. It was shown that the removal efficiency of TDS, T-N and COD was very low and was not dependent on the variation of temperature and pressure in all UF modules. The removal efficiency of TDS, T-N and COD was very excellent in RO module. Final water quality of acrylic wastewater was satisfied with effluent allowances limit and membrane module sets were ascertained to reuse wastewater. 아크릴 폐수를 응집-여과-중화의 전처리 공정에 적용하여 막오염 인자를 최소화 한 후 UF/RO 공정에 적용하였다. 막의 형태 및 종류에 따라 한외여과 및 역삼투 모듈을 조합을 이루어 전처리 수를 온도 및 압력변화에 따라 적용하여 분리 특성을 고찰하였다. 투과 플럭스는 모듈 set 1의 UF모듈보다 모듈 set 4의 UF모듈의 투과량이 약 $2{\sim}3$배 더 많이 배출됨을 확인하였다. 최종적인 투과량은 관형모듈과 조합을 이룬 모듈 set 2와 모듈 set 3이 좋은 결과를 나타내었다. 모든 UF 모듈에서 TDS, T-N 및 COD의 제거 효율은 온도 및 압력변화에 영향을 받지 않고 제거 효율 또한 낮음을 알 수 있었다. RO모듈에서 TDS, T-N 및 COD가 우수한 제거 효율을 보였다. 아크릴 폐수의 최종적인 수질결과는 공장폐수의 배출 허용기준을 만족하였고, 막모듈 조합은 폐수의 재활용 가능성을 확인할 수 있었다.