폐머리카락을 이용한 중금속의 흡착특성에 관한 연구

홍승목,정진희,장나영,김한석,이기형,김명숙,성낙창 東亞大學校 附設 環境問題硏究所 2008 硏究報告 Vol.29 No.1

The current study conducted experiments for property analysis regarding heavy metal absorption, iodine adsorption and porosity using waste hair as a reclamation method of waste hair. The study also observed pore distribution of hair using a Scanning Electron Microscope(SEM) and examined the possibility of removing heavy metal from hair. That is, the purpose of the current study is to evaluate environmental risk and economical efficiency by comparing hair with other biomass resources, activated carbon, etc. heavy metal removal efficiency was analyzed wrule heavy metal concentration 10 ppm, time variables were 5min, 15min, 30min, 60min and 120min, temperature was 20 .C, and pH 3

트랙터부착형 배추수확장치의 설계요인

홍종태,최용,성제훈,김영근,이기영 한국농업기계학회 2001 바이오시스템공학 Vol.26 No.4

熱分解된 Polyacrylonitrile의 電氣的 性質

成墉吉,李延煥,李載珍,李丁桂,洪致裕,姜泰遠 동국대학교 자연과학연구소 1984 자연과학연구 논문집 Vol.4 No.-

질소 분위기 하에서 200ㄹ7로 열처리한 PAN 膜을 10³V/cm~10⁴V/cm의 電氣場을 걸어 分極시킨 후 溫度變化에 따른 TSD 電流를 測定하였다. 이 같이 分極된 PAN의 TSD spectrum은 nitrile side group의 방향의 弛緩에 관계되는 한개 또는 두개의 peak를 나타냈으며, 이것으로부터 5×10³V/cm의 電氣場에서 分極시킨 PAN膜의 trap energy level은 0.545 eV이었다. The electric behavior of the polyacrylonitrile(PAN) pyrolyzed at 200℃ in the N₂gas is investigated through the formation fo electrically polarized films. The formation fo the films is achieved by applying electric fields of the order 10³-10⁴V/cm to the prepared PAN specimens at the tmeperature ranging from 100℃ to 200℃. The TSD spectrum of PAN reveals one or twonpeaks, which might to related to the relaxation of oriented nitrile side group. This suggests that nitrile orientation with an applied electric field results in the formation of a highly developed level of intermolecular bonding. The polarized PAN film by the field of 5×10³V/cm at 200℃ also shows the trap level of 0.545 eV above the valence band.

Quasi-Monoenergetic Electron-Beam Generation Using a Laser Accelerator for Ultra-Short X-ray Sources

J Kim,고도경,석희용,H Jang,김형택,I Hwang,최일우,J Lim,J. Lee,J. H. Sung,K.-H. Hong,허민섭,N Hafz,유승훈,유태준,T. M. Jeong,V Kulagin,Y.-C. Noh 한국물리학회 2007 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.51 No.I

Two types of electron acceleration methods have been conducted to generate quasi-monoenergetic electron beams. Multi-MeV quasi-monoenergetic high-charge electron beams were generated at Korea Electrotechnology Research Institute (KERI) from self-modulated laser wakefield acceleration by using a collimator with a 2 TW (1.4 J/700 fs) Nd:glass/Ti:sapphire hybrid laser system and a supersonic nitrogen gas jet. The peak electron energy was 3.6 MeV, and the energy spread was 4 MeV. These electron beams are useful for the generation of short-pulse X-rays in the water window region, which is 250 eV -- 500 eV (2.5 -- 5 nm), by using Thomson scattering. The calcualted photon spectrum indicates the scattered photon covers the water window region. This can be used for a high spatial and temperal resolution microscope for medical imaing. To generate higher-energy electron beams with small energy spread, a laser wakefield acceleration experiment with a sharp downward electron density gradient was conducted with a 100 TW laser system at Advanced Photon Research Insistitute (APRI). With the electron density gradient, some background plasma electrons could be locally injected in the laser wake wave and a small energy spread was expected. Using the pre-pulse, we could generate sharp downward electron density gradients. The gradient scale length was 20 $\mu$m for a 25 \% density change. With this electron density gradient, we could get more reproducible electron beams than we could without the density gradient.

폐머리카락을 이용한 중금속의 흡착특성에 관한 연구

홍승목,정진희,장나영,김한석,이기형,김명숙,성낙창 동아대학교 환경문제연구소 2008 硏究報告 Vol.30 No.1

The current study conducted experiments for property analysis regarding heavy metal absorption, iodine adsorption and porosity using waste hair as a reclamation method of waste hair. The study also observed pore distribution of hair using a Scanning Electron Microscope(SEM) and examined the possibility of removing heavy metal from hair. That is, the purpose of the current study is to evaluate environmental risk and economical efficiency by comparing hair with other biomass resources, activated carbon, etc. heavy metal removal efficiency was analyzed wrule heavy metal concentration 10 ppm, time variables were 5min, 15min, 30min, 60min and 120min, temperature was 20 .C, and pH 3

CIP 법을 이용한 다상 이동경계면에 대한 해석

박준홍,홍희기,김경훈,이상렬 경희대학교 산학협력기술연구원 1998 산학협력기술연구논문집 Vol.4 No.-

The CIP(Cubic-Interpolated propagation) method which can solve together compressible and incompressible fluid is used to calculate multi-phase moving boundary. As test problems, C-CUP(CIP-Combined Unified Proocedure) was applied to a cavity flow and a broken dam, which have been verifid by lots numerical techniques and experiments. In the cavity flow, the distribution velocity calculated by the CIP method shows a good agreement with that of SIMPLE. In the simulation of collapsing process of dam, exact and sharp boundary was obtained on flowing water, although simple boundary conditions are used only on the rectangular region not water-air interface.

Ba0.7Sr0.3TiO3 세라믹스의 소결온도, 성형압력에 따른 격자 뒤틀림과 유전 특성과의 관계

임성민,홍석민,박홍진,김옥경 한양대학교 이학기술연구소 2000 이학기술연구지 Vol.2 No.

소결온도와 성형압력을 각각 조절하여 Ba0.7Sr0.3TiO3 세라믹스의 결정립의 크기를 조절한 후 이에 따른 격자 뒤틀림의 변화와 유전특성과의 관계를 조사하였다. 소결온도와 성형압력이 증가함에 따라 결정립의 크기는 모두 증가하였지만 격자 뒤틀림은 소결온도가 증가함에 따라 감소하는 반면 성형압력의 증가에 대한 영향으로 증가하였지만 성형압력을 변화시킨 시편은 격자 뒤틀림의 변화와 마찬가지로 큰 변화를 나타내지 않았다. 유전변화율(dielectric tunability)은 성형압력을 변화시킨 시편이 소결온도를 변화시킨 경우보다 더 크게 나타났다. Ba0.7Sr0.3TiO3 ceramics with various grain sizes were prepared to investigate the lattice distortion dependence of dielectric properties by controlling sintering temperature and pressing. The grain sizes of the samples are increased with increasing sintering temperature and pressing pressure. The dielectric constant is increased by increasing sintering temperature due to the decrease in lattice distortion while it is not much affected by controlling pressing pressure. The sample made by controlling pressing pressure have greater dielectric tunability than those made by controlling sintering temperature.

정상한국인 및 각종갑상선질환에서의 아킬레스건반사 시간에 관한 연구

강진영,김명덕,이홍규,이정상,고창순,이문호 대한핵의학회 1978 핵의학 분자영상 Vol.12 No.1

"Since Chaney reported the measurement of ankle jerk in Patients with myxedema for the first time, slowing of the reflex in myxedema has been well documented by many authors. Although its mechanisms have not been elucidated clearly, it has long been held in esteem by clinicians a near pathognomonic sign in myxedema. Possible mechanisms suggested include (a) abnormal activity of the central nervous system, (b) a disorder of muscle like that of myotonia (c) lowered temperature of the muscle, (d) increased viscosity of themuscle due to myxdematous infiltration and (e) part of a general slowing of all vital processes. The brisk reflex in thyrotoxicosis has also been noted to be characteristic. The recent development of several simple methods of quantitating the deep tendon reflex time has made its application an easy, rapid, inexpensive and accurate test in the results of our examinations on the Achilles tendon reflex(ATR) times in normal Koreans along their sexes, ages and in various thyroid diseases. Also we observed the changes of ATR times in the thyrotoxicosis and myxedema after the initiation of treatment and compared them with other thyroid function tests. "

서울지역 4년제 간호대학생들의 임상실습 유,무에 따른 진로태도성숙

권혜진,김보람,김소연,김수임,성정아,신영미,윤서진,이경진,홍영선,이자형,정덕유,신혜원 이화여자대학교 간호과학대학 2009 이화간호학회지 Vol.- No.43

This study was conducted to investigate the differences in the degrees of career attitude maturity according to the clinical practice experience of the college of nursing students. The convenience sample was 275 students attending the college of nursing in Seoul. Data was obtained through a questionnaire from December 1st to 12th, 2008. The instrument used to measure the career attitude maturity in this study was "A barometer of maturity in career attitudes" developed by Ki-hak, Lee(1997). The collected data were analyzed by descriptive statistics, Chronbach's alpha, t-test and ANOVA with the SPSS 16.0 program. Below is the result of this study. 1. The average score for career attitude maturity of nursing students who experienced clinical practices was 135.56(±12.17): higher than the average score of inexperienced students, 134.37(±12.44). However it could not show meaningful differences in the statistics(F=-.805, p=.422). 2. Determinacy, one of five subordinate concepts of career attitude maturity, was statistically significative. On average, the group comprised of students with clinical practices scored 27.60(±3.81): higher than that of unpracticed students, 26.63(±4.26)(F=-1.976, p=.049). 3. The more academic years they have, except for junior year students, the points of career attitude maturity relative to general characteristics were increasingly higher. The points were 132.60(±11.99) for freshmen, 135.93(±12.72) for sophomores, 133.50(±12.57) for juniors and 138.11(±11.24) for seniors(F=2.714, p=.045). 4. According to the age of the group, the grade of career attitude maturity became higher. The scores were 133.21(±12.34) for 18-19yrs., 134.05(±12.16) for 20-22yrs., 138.43(±10.96) for 23-26yrs. and 148.71(±12.76) for 27-32yrs. (F=5.118, p=.002). 5. The average total score for career attitude maturity of nursing students was 135.00(±12.30). Of the five subdivisions―readiness, conviction, determinacy, independence and finality― readiness demonstrated the highest result with 32.33(±4.46) followed by conviction, determinacy, independence and finality respectively. Based on the results, there are some proposals for further researches. As this research was only for college of nursing in Seoul, it is necessary to compare career attitude maturity with 3-year colleges and other departments. In addition, alongside clinical practices there is a growing need to develop programs that will not only provide guidelines but also prepare students for the maturity of their career attitude.

Effect of boron addition on thermal and mechanical properties of Co-Cr-Mo-C-(B) glass-forming alloys

Kim, Jeong Tae,Hong, Sung Hwan,Bian, Xilei,Gokuldoss, Prashanth Konda,Song, Kaikai,Eckert, Jü,rgen,Park, Jin Man,Kim, Ki Buem Elsevier 2018 INTERMETALLICS Vol.99 No.-

<P><B>Abstract</B></P> <P>In this work, we investigated the effect of boron addition on glass-forming ability and mechanical properties of Co-Cr-Mo-C alloys. The starting alloy was (Co<SUB>0.65</SUB>Cr<SUB>0.13</SUB>Mo<SUB>0.22</SUB>)<SUB>80</SUB>C<SUB>20</SUB> derived from the Co<SUB>65</SUB>Cr<SUB>13</SUB>Mo<SUB>22</SUB> ternary eutectic composition. This alloy is almost fully crystalline and exhibits brittle mechanical properties. Replacing carbon with boron allows obtaining bulk metallic glasses (BMGs) and bulk metallic glass composites. The designed alloys show very high strength (∼4100 MPa), wide super-cooled liquid region (∼100 K) and large endothermic enthalpy of the supercooled liquid region (∼35 J/g), indicating high thermal stability. The electronegativity difference and supercooled liquid region of the present alloys are comparable to rare-earth elements containing BMGs. The physical properties of the present alloys corresponded well with the alloy design strategy based on the unified parameter using the glass transition temperature, fracture strength, and molar volume. Furthermore, we propose the optimum compositional condition for glass formation by controlling the carbon-to-boron ratio and the influence of carbon on phase formation in this alloy system is discussed.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Effect of boron/carbon ratio on the glass formation, fracture strength, and thermal stability of Co-Cr-Mo eutectic alloy. </LI> <LI> The wide supercooled liquid region of 100 K when carbon to boron ratio is 2:1. </LI> <LI> The excellent thermal stability of supercooled liquid can offer a wide enough processing window for thermoplastic forming. </LI> <LI> The electronegativity difference is an indicator dominating the extension of the supercooled liquid region. </LI> </UL> </P>