Kinetics of Hydrogen Movement in Zinc

Jeong_Keun Lee 한국물리학회 2007 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.51 No.II

The diffusivity of hydrogen in pure zinc was determined by using hydrogen extraction with cylindrical specimens of 1 cm in diameter and 1 cm in length. The measured values of the diffusivity did not vary statistically with the purity of the zinc, which indicates that the grain boundary did not play an important role in the hydrogen evolution from zinc. The values of the diffusivity obtained in the temperature range from 50 to 300 $^\circ$C showed that the diffusivity depended exponentially on the temperature. The repeatability of the hydrogen extraction method at low temperatures was better than that at high temperatures. A combination of the measured value of the frequency factor, $D_0$, with Zenner's theoretical expression of $D_0$ for interstitial diffusion yielded a negative value of the activation entropy, $\Delta S$, which was explained by the hypothesis that the change in the vibrational frequency of hydrogen particles that jumped between adjacent sites contributed more to $\Delta S$ than the zinc lattice distortion caused by the movement of hydrogen particles did.

정상인에서 부분적 수면박탈이 수면구조에 미치는 영향

왕성근,이정규,이충숙,최하석,유남재,정인형,이선우 충남대학교 의과대학 지역사회의학연구소 1992 충남의대잡지 Vol.19 No.2

To identify the effects of partial sleep deprivation on the sleep structure, the authors performed polysomnographic study for 9 healthy young adults. The subjects were college students, ranging in age from 20 to 25 years, without personal past or present histories of medical, neurological, or psychiatric illness and suffering from current sleep disturbance or parasomomnias. Sleep records were analyzed according to the criteria of Rechtschaffen and Kales' manual and tried paired t-test. The results were summarized as follows. 1. As for sleep parameters, total sleep time(TST), REM latency and REM duration were not changed significantly during deprivation period and recovery period compared with baseline. Sleep efficiency increased significantly during deprivation period and recovery period compaired with baseline, and sleep latency and WASO were shortened significantly during deprivation period and recovery period compared with baseline. 2. As for sleep structure, 1) The absolute value(minutes) of stage 1 decreased significantly during deprivation period and first recovery night compared with baseline, and the relative value(percentage) of stage 1 decreased significantly during deprivation period and recovery period compared with baseline. 2) The absolute value(minutes) of stage 2 decreased significantly during deprivation period compared with baseline, and the relative value(percentage) of stage 2 decreased significantly during deprivation period and first recovery night compared with baseline. 3) The absolute value(minutes) of slow wave sleep were not changed significantly during deprivation period and recovery period compared with baseline, and the relative value(percentage) of slow wave sleep increased significantly during recovery period compared with baseline. 4) The absolute value(minutes) of REM sleep decreased significantly during deprivation period compared with baseline, and the relative value(percentage) of REM sleep decreased significantly in the first deprivation night but, were not changed significantly during recovery period compared with baseline.

추황배(Pyrus pyrifolia Nakai cv. Chuhwangbae) 과피로부터 1종의 Sterol과 3종의 배당체 화합물의 단리·동정

이유건(Yu Geon Lee1),조정용(Jeong-Yong Cho),이현주(Hyun Joo Lee),이용현(Yong Hyun Lee),이상현(Sang-Hyun Lee),한태호(Tae-Ho Han),김월수(Wol-Soo Kim),박근형(Keun-Hyung Park),문제학(Jae-Hak Moon) 한국식품과학회 2013 한국식품과학회지 Vol.45 No.5

본 연구에서는 배의 유용성 증명을 위한 일환으로 배의 화학성분을 분자수준에서 밝히고자 하였다. 이에 배 과피 MeOH 추출물을 용매분획하여 얻은 EtOAc-산성 분획과 EtOAc-중성분획을 대상으로 Sephadex LH-20, silica gel, 그리고 ODS colmn chromatography와 HPLC를 이용하여 정제 및 단리하였다. 그 결과, EtOAc-산성 분획과 EtOAc-중성 분획으로부터 각각 2종씩의 화합물을 단리하였다. 단리된 화합물 1-4는 1H- 및 13C-NMR 분석을 통하여 각각 (S)-(+)-2-cis-abscisic acid O-β-D-glucopyranosyl ester (화합물 1), 1-[4-O-β-D-glucopyranosyl]phenyl ethanone(piceoside, 화합물 2), β-sitosterol (화합물 3), 그리고 β-sitosteryl 3-O-β-D-glucopyranoside (화합물 4)로 동정되었다. 단리된 3종의 배당체 화합물(화합물 1, 2, 4)들은 본 연구에 의해 배로부터 처음 동정되었으며, 화합물 3은 추황배로부터 처음 동정되었다. 본 연구결과가 배 함유 성분연구는 물론 배의 기능성 해명 연구에도 추후 중요한 기초자료로 활용되길 기대한다. We isolated and identified antioxidants from acidic and neutral ethyl acetate fractions of the peel of pear (Pyrus pyrifolia N. cv. Chuhwangbae). We isolated 4 compounds from the methanol extract, by using 3 different types of column chromatography (Sephadex LH-20, silica gel, and octadecylsilane) and preparative HPLC. We identified the isolated compounds as (S)-(+)-2-cis-abscisic acid O-β-D-glucopyranosyl ester (compound 1), 1-[4-O-β-D-glucopyranosyl]phenyl ethanone (picroside, compound 2), β-sitosterol (compound 3), and β-sitosteryl 3-O-β-D-glucopyranoside (compound 4) by nuclear magnetic resonance analysis. We are the first to report the identification of compounds 1, 2, and 4 from pear.

지난 2년간의 학회지 "신경정신의학" 심사 평가보고

김찬형,김세주,김도관,김성곤,박원명,송동호,박용천,이영문,오강섭,정영철,이상열,김주한,이동영,이헌정,함병주,김율리,김문두,김정진,이강욱,천근아,김재진,홍진표,홍승철 大韓神經精神醫學會 2007 신경정신의학 Vol.46 No.6

韓國自然部落 形態空間論 : 慶北 月城郡 江東面 良洞部落을 中心으로

李廷根 울산대학교 1978 연구논문집 Vol.9 No.2

慶北地方內 2個 部落을 選定해서 形態學的 接近法에 따라 部落의 建築環境을 그의 社會構造와 연관해서 분석해 보았다. The architectural environment of two Villages in Kyung Buk Prorince is Analysed through morphological approach. The study of form and pattern of the artificial spaces in relation to the social structure of their inhabitant's is the main theme of this notes.

고선량 방사선 조사후 치아수복재의 특성변화

이용근,이건일,이성재,박수아,허정무 원광대학교 생체재료·매식연구소 1996 원광생체재료·매식 Vol.5 No.2

To investigate the effect of high dose irradiation on the Vickers hardness number(VHN), color change and wear rate of dental filling materials, esthetic filling material specimens were studied. Six kinds of composite resins and two kinds of glass ionomers(GI) were used. One(CLF) was chemically cured composite resin, and five(HCX, HPL, PHB, POF, PRT and RZI) were light cured composite resins. One(FJT) of GI was chemically cured GI and one(FLC) was light cured GI. The filling material specimens were made according to the manufacture's instructions and were finally polished with Microcloth(Buehler). Half of the specimens were irradiated with 100 Gy radiation using a linear accelerator(Mitsubishi, 6 MV). VHN and CIELAB color were measured before and after irradiation, and wear test were performed for nonirradiated specimens by brushing with toothpaste, From the experiment , the following results were obtained. 1. The CIELAB color difference was significantly different depending on the material(p<0.01), and FLC showed the highest color difference (CIELAB ΔE) of 9.452 and CLF showed the lowest value of 3.642. 2. The VHNs of nonirradiated specimens were 12.22∼73.58 and those of irradiated specimens were 25.53∼84.53. The VHNs of irradiated specimens were significantly higher than those of nonirradiated specimens(p<0.05) except RZI, FJT and FLC. 3. The wear rate of irradiated specimens of RZI, FLC were significantly lower than those of nonirradiated specimens(p<0.05). 4. The color difference after brushing of irradiated specimens were higher than those of nonirradiated specimens except CLF.

편측성 완전 구순구개열 환자의 포괄적 치료

이정근,황병남,최은주,김용빈 대한악안면성형재건외과학회 2000 Maxillofacial Plastic Reconstructive Surgery Vol.22 No.4

Cleft lip and palate is one of the congenital anomalies which need comprehensive and multidisciplinary treatment plan because 1) oral cavity is an important organ with masticatory function as a start of digestive tract, 2) anatomic symmetry and balance is esthetically important in midfacial area, and 3) it is also important to prevent psycho-social problems by adequate restoration of normal facial appearance. There are many different protocols in the treatment of cleft lip and palate, but our department has adopted and modified the Z□rich protocol, as published in the Journal of Korean Cleft Lip and Palate Association in 1998. The first challenge is feeding. Type of feeding aid ranges from simple obturators to active orthopedic appliances. In our department we use passive-type plate made up of soft and hard acrylic resin which permits normal maxillary growth. We use Millard's method to restore normal appearance and function of unilateral complete cleft lip. In consideration of both maxillary growth and phonetic problems, we first close soft palate at 18 months of age and delay the hard palate palatoplasty until 4 to 5 years of age. When soft palate is closed, posterior third of the hard palate is intentionally not denuded to allow normal maxillary growth. In hard palate palatoplasty the mucoperiosteum of affected site is not mobilized to permit residual growth of the maxilla. We have treated a patient with unilateral complete cleft lip and palate by Ajou protocol, which is a kind of modified Z□rich protocol. It is as follows: Infantile orthopedics with passive-type plate such as Hotz plate, cheiloplasty with Millard's rotation-advancement flap, and two stage palatoplasty. It is followed by orthodontic treatment and secondary osteoplasty to augment cleft alveolus, orthognathic surgery, and finally rehabilitation with conventional prosthodontic treatment or implant installation. The result was good up to now, but we are later to investigate the final result with longitudinal follow-up study according to master plan by Ajou protocol.

Al-Sn 합금의 마찰 특성에 미치는 Sn 형상의 영향

李定根,朱大憲,金文鉉,金明鎬 대한금속재료학회 2002 대한금속·재료학회지 Vol.40 No.10

Effects of Sn morphology on the friction and wear characteristics of Al-Sn alloys were investigated by using the tribology tester, optical microscope and scanning electron microscope. Three different types of Sn morphologies named elongated, small network and large network structure were obtained by cladding and heat treatment. Wear resistance of the specimen having large network structure exhibited better anti-friction characteristics compare to that of the elongated structure. Also specific wear rate and friction coefficient decreased markedly with change of Sn morphology from elongated to large network structure. Abrasive and adhesive wear occurred for the elongated structure, while oxidation wear was observed for the network structure.

불포화 폴리에스테르 수지의 물성이 폴리머 콘크리트의 강도에 미치는 영향

이필호,박재근,황보 영,이정우 강원대학교 석재복합신소재제품연구센터 1996 석재연 논문집 Vol.1 No.-

본 연구에서는 폴리머 콘크리트의 결합재인 불포화 폴리에스테르 수지(UPR)의 물리적 성질을 조사하였다. 그 결과는 비중 1.1 g/mL, 점도 3.0 poise, styrene의 함량은 40% 내외이고 산값은 약 20이었다. 본 실험에서 제조된 폴리머 콘크리트의 압축강도는 평균 1,056 Kg/cm², 휨강도는 216 Kg/cm², 인장강도는 110 Kg/cm²이었는데, 이는 시멘트 콘크리트에 비해 비교적 좋은 역학적 성질을 나타낸 것이다. 변동계수는 압축강도의 경우 약 3%, 휨강도의 경우 5%, 인장강도의 경우 6% 내외로서 매우 양호하다. 강도비를 산출하여 본 바 압축강도와 휨강도의 비가 4.9, 압축강도와 인장강도의 비가 9.7, 휨강도와 인장강도가 1.97로서 나타났는데 이는 폴리머 콘크리트의 압축강도는 1000 Kg/cm²를 상회함을 감안할 때 휨 및 인장강도가 상대적으로 큼을 보여주는 결과이다. In this study, effect on the strength of polymer concrete of unsaturated polyester Resin's(UPR) property was investigated. The physical property of UPR was as follows; density 1.1 g/mL, viscosity 3.0 poise, the content of styrene 40%, and acid value 20. The mechanical property of Polymer Concrete was relatively good; compressive strength 1,056 Kg/cm², flexural strength 216 Kg/cm², splitting tensile strength 110 Kg/cm², The coefficient of fluctuation was 3% of compressive strength, 5% of flexural strength, and 6% of splitting tensile strength. The ratios of respective strength were 4.9(compressive strength to splitting tensile strength), and 1.97(flexural strength to splitting strength). Therefore, flexural strength and splitting tensile strength of polymer concrete was relatively big under consideration of compressive strength(1,000 Kg/cm²).

미생물 포괄 고정화방식을 이용한 수산물 가공공장 폐수처리

정병철,장수현,김종배,김건배,최선남,이근우,정병곤 7개 국립대학교 환경연구논문집 공동발행 위원회 2005 공업기술연구 Vol.5 No.-

Feasibility of simultaneous removal of organic and nitrogen is evaluated as applying microbial entrapping method to treat fish processing wastewater. Treatability test is conducted immobilizing activated sludge from municipal sewage treatment plant to gel matrix made of cellulose triacetate. Stable operation can be possible when applying organic and nitrogen loading rate increasingly to wastewater treatment system composed of anoxic and oxic tank. Organic loading rate and nitrogen loading rate are applied 0.65-1.72kg COD/㎥/d and 0.119-0.317kg T-N/㎥/d, respectively. In case of wastewater from fish processing plant used in this study, it is evaluated that 0.3kg T- N/㎥/d is upper limit of applicable space loading rate because effluent T-N concentration is exceed 60mg/L, legal effluent dishargeable limit of T-N concentration in Korea, when space loading rate is exceed 0.3kg T-N/㎥/d. It is evaluated that nitrification of system is performed efficiently regardless fo variation of applied loading rate because removal efficiency of NH_(4)^(+)-N is relatively constant when the applied NH_(4)^(+)-N loading rate is increased gradually, while decrease of T-N removal efficiency is apparent when the applied loading rate is increased gradually. Nitrate removal efficiency in this study is varied from 98.62% to 99.51% depending on applied loading rate, while nitrification efficiency of oxic reactor is varied from 94.0% to 96.9%. It is showed that COD removal efficiency is varied from 94.2% to 96.6% and T-N removal efficiency is varied from 73.4% to 83.4% depending on loading rate applied in this study.