초등학교에서 에너지의 합리적 사용을 위한 STS 프로그램의 개발과 적용 효과

최상길,김채복,최준섭 韓國實科敎育硏究學會 2002 實科敎育硏究 Vol.8 No.1

The purpose of this study was to develop STS teaching-learning program which focuses on real-life experiences for reasonable energy usage, and to verify how STS teaching-learning program affects the understanding knowledge concerned energy and the attitude towards saving energy. The subjects of this study were students of the 6th grade at an elementary school in Kyong-Ju. They were divided into two groups, an experimental group and a control roup. The developed STS teaching-learning program had been applied to the experimental group. However, the traditional teaching-learning process had been employed to the control group for four weeks. The main results of this study are as follows : (1) The developed STS teaching-learning program consists of following subjects ; energy resources, growing energy consumption, heat-energy transfer, energy and environment, saving energy, efficient usage of electricity and opening ‘ANABADA’ market. (2) In the understanding of knowledge concerned energy, there was no difference between the experimental group and control group. (3) In the attitude toward saving energy, there was a considerable significant difference between he experimental group and control group. However, there was no difference between male and female students, respectively.

감의 脫澁處理中 Pectin 含量과 Texture의 變化

崔鍾旭,孫泰華,鄭信敎,李吉雨,姜峻洙 慶北大學校 1989 論文集 Vol.47 No.-

This experiment was made to investigate the changes of the contents of acetaldehyde, alcohol, tannin, and to study the texture changes of persimmon in relation to the contents of pection during the removal of astringency by CO_2. 1. During the removal of astringency of persimmon fruits, the contents of soluble tannin showed the rapid decrease in high concentration of CO_2, but the contents of ethanol and acetaldehyde showed the rapid increase in all treatments. 2. The contents of W.S.P. increased, but H.S.P. decreased in all treatments. 3. All texture paramenters of persimmon fruits except springness and adhesiveness were decreased druing the removal of astringency. 4. The contents of W.S.P. were good correlated with the changes of hardness in all treatments.

Streptomyces thermocyaneoviolaceus의 Xylanase 생산조건 및 Xylooligo당의 생산

주길재,박희동,최준호,이인구,이오석,권달호 慶北大學校農業科學技術硏究所 1998 慶北大農學誌 Vol.16 No.-

농산폐자원으로부터 기능성물질인 xylooligo당을 생산하기 위해서 내열성 균주인 S.thermocyaneoviolaceus가 생산하는 xylanase의 생산최적조건을 검토한 결과 0.8% 밀기울, 0.06% yeast extract, 0.06% bactopeptone, 0.05% MgSO₄·7H₂O, 0.005% FeSO₄·7H₂O, 0.05% KH₂PO₄및 0.2% K₂HPO₄를 함유한 배지(pH7.0)에서 50℃, 24시간 배양시 최고효소활성(2.47 unit/ml)의 배양상징액을 얻을 수 있었다. 효소의 최적반응조건은 pH5.5, 65℃였다. 또한 pH안정성을 조사한 결과 pH4.5∼9.5사이에서 4℃에서 12시간후에도 80% 이상의 효소활성을 유지하였고, 열 안정성은 60℃에서 1시간 처리후 94%이상의 효소활성을 유지하는 내열성이 있는 효소였다. 생산된 xylanase birchwood xylan 반응생성물을 TLC 및 HPLC로 확인해 본 결과, pH가 낮을수록(pH 5.0∼6.0) xylobiose와 xylotriose및 소량의 xylose의 양이 증가하였고, pH가 높을수록 (pH8.0∼9.0) X₄이상의 각종 xylooligo당의 양이 상대적으로 증가하였다. 또한 24 시간후에는 xylan의 상대량이 25% 이하로 감소하면서 주분해산물로 xylobiose가 생산되었으며 xylotriose와 xylose 및 X₄이상의 각종 xylooligo당이 생산되었다. A thermotolerant bacterium, Streptomyces thermocyaneoviolaceus which produced xylan-degrading enzymes, utilized excellently xylan of wheat bran by producing the enzymes in comparison with that of birchwood or oat spelts. Optimal enzyme production was achieved in WB medium containing 0.8% wheat bran, 0.06% yeast extract, 0.06% bactopeptone, 0.05% MgSO₄·7H₂O, 0.05% FeSO₄·7H₂O, 0.05% KH₂PO₄ and, 0.2% K₂HPO₄(pH 7.0) at 50℃ for 24 hrs. The optimal pH and temperature for the hydrolysis of xylan were pH 5.5 and 65℃, respectively. The enzyme activity was retained more than 80% at the range from pH 4.5 to pH 9.5 at 4℃ for 12 hrs and 94% on the heat-treatment at 65℃ for 1 hr. Xylobiose, xylotriose, xylose, and other xylooligosaccharides were produced as end products from hydrolysis of birchwood xylan by the xylanase of S. thermocyaneoviolceus.

니트섬유강화 복합재료의 기계적 성질에 관한 연구

한길영,이동기,최병기,오환교,신용욱,전수영 조선대학교 에너지.자원신기술연구소 1999 에너지·자원신기술연구소 논문지 Vol.21 No.2

Using conventional textile techniques such as weaving, braiding, knitting and stitching it is possible to produce a wide range two and three dimensional fiber preforms. However, so far only a limited attention has been given to knitted fabrics in composite industry. This is mainly due to the opinion that knitted fabric reinforced composites posses low mechanical properties owing to their looped fiber architecture. But it is possible to obtain desired mechanical properties by selecting proper knitted fabric structure. In this paper, tensile failure load and displacement of one yarn, four yarns and knitted fabrics of ten yarns of kevlar fiber were determined experimentally in the unidirection. Mechanical properties of plain weft knitted fabrics reinforced composite intrusion beam for car side door application were investigated experimentally, which compared with desire value of American Fedral Motor vehicles Safety Standard (FMVSS) and presented the results.

컴퓨터 모의실험을 이용한 Stop-and-wait ARQ 기법 성능 평가

이용학,이호준,최길용,장재신 인제대학교 2012 仁濟論叢 Vol.27 No.1

ARQ schemes are commonly used in various communication areas, for instance TCP protocol, to combat communication packet errors and there are three different types of ARQ protocol. In this paper, the performance of stop-and-wait ARQ scheme is evaluated with computer simulation and then compared with analytical results. Two different traffic generation modes are considered: the first one is the saturated traffic model and the other one is periodic arrival model based on exponential distribution. For performance measures, link utilization and average packet delay are used in this paper. According to numerical results, it is known that performance results from computer simulations coincide well with those by mathematical analysis. For the further study, we will continue to carry performance evaluations of two other ARQ schemes, go-back-N ARQ and selective repeat ARQ schemes.

발아조건과 배지종류 및 양액 농도에 따른 식물공장 재배 청경채와 상추의 묘 생육특성

최효길(Hyo-Gil Choi),권준국(Joon-Kook Kwon),박경섭(Kyoung-Sub Park),강윤임(Yun-Im Kang),조명환(Myeong-Whan Cho),노일래(Il-Rae Rho),강남준(Nam-Jun Kang) (사)한국생물환경조절학회 2011 생물환경조절학회지 Vol.20 No.4

본 연구는 식물공장에서 청경채와 상추의 발아조건과 육묘배지 및 육묘 시 양액농도가 묘의 생육에 미치는 영향을 구명하고자 수행되었다. 청경채와 상추의 발아율은 광의 유무와 온도처리(15, 20, 25℃) 간에 유의적 차이가 없었으나, 육묘배지 간에는 우레탄스펀지의 경우 파종 전ㆍ후 수분관리 유ㆍ무에 따라 큰 차이를 보였다. 즉, 우레탄스펀지 배지에서 파종전ㆍ후 수분관리를 하지 않았을 경우 암면에 비해 발아율이 현저히 낮았으나, 수분관리를 해주었을 때에는 암면보다 발아율이 높았으며, 묘의 생육도 암면과 차이가 없었다. 그리고 청경채의 생체중은 EC 1.0dSㆍm?¹에서 1.5dSㆍm?¹에서보다 1.8배 무거웠고, 0.5dSㆍm?¹에서보다는 6배 무거웠다. 상추의 생체중 또한 EC 1.0dSㆍm?¹이 1.5dSㆍm?¹와 0.5dSㆍm?¹에 비해 1.7배와 3.5배 각각 무거웠다. This experiment was conducted to study the effects of germination condition, nursery media and nutrient concentration in plant factory on the growth characteristics of pak-choi and lettuce seedlings. The results showed that temperature (15, 20, 25℃) and light conditions (lighting and no lighting) had no significant effect on germination rate of pak-choi and lettuce, whereas the interaction of growing media (rockwool and urethane sponge) and moisture management before and after sowing had significant effect on germination percentage. In case of no moisture management before and after sowing, germination percentage was much higher in rockwool medium than urethane sponge medium. But germination percentage of urethane sponge was higher than that of rockwool with applying moisture before and after sowing. At the nutrient concentration of EC 1.0 dSㆍm?¹ the fresh weight of pak-choi was heavier than in EC 1.5 and 0.5 dSㆍm?¹ by 1.8 and 6.0 times, respectively. At the nutrient concentration of EC 1.0 dSㆍm?¹ the fresh weight of lettuce was also heavier than in EC 1.5 and 0.5 dSㆍm?¹ by 1.7 and 3.5 times, respectively.

Generation of viable embryos and embryonic stem cell-like cells from cultured primary follicles in mice.

Choi, Jun Hee,Kim, Gil Ah,Park, Jong Heum,Song, Gwon Hwa,Park, Jun Won,Kim, Dae Yong,Lim, Jeong Mook Society for the Study of Reproduction [etc.] 2011 BIOLOGY OF REPRODUCTION Vol.85 No.4

<P>Primary follicles retrieved from B6CBAF1 prepubertal mice were cultured in a stepwise manner in an alpha-minimum essential medium-based medium to generate viable embryos and embryonic stem cell (ESC)-like cells. A significant increase in follicle growth and oocyte maturation accompanied by increased secretion of 17beta-estradiol and progesterone was achieved by exposing primary follicles to 100 or 200 mIU of follicle-stimulating hormone (FSH) during culture. More oocytes developed into blastocysts following in vitro fertilization (IVF) or parthenogenetic activation after culture with 200 mIU of FSH during the entire culture period than with 100 mIU. Eleven ESC-like cell lines, consisting of four heterozygotic and seven homozygotic phenotypes, were established from 25 trials of primary follicle culture combined with IVF or parthenogenetic activation. In conclusion, primary follicles can potentially yield developmentally competent oocytes, which produce viable embryos and ESC-like cell lines following in vitro manipulation. We suggest a method to utilize immature follicles, which are most abundant in ovaries, to improve reproductive efficiency and for use in regenerative medicine.</P>

Role of Cu in Mo₆S₈ and Cu Mixture Cathodes for Magnesium Ion Batteries

Choi, Seung-Hyun,Kim, Jeom-Soo,Woo, Sang-Gil,Cho, Woosuk,Choi, Sun Yong,Choi, Jungkyu,Lee, Kyu-Tae,Park, Min-Sik,Kim, Young-Jun American Chemical Society 2015 ACS APPLIED MATERIALS & INTERFACES Vol.7 No.12

<P>The reversible capacity of Chevrel Mo<SUB>6</SUB>S<SUB>8</SUB> cathode can be increased by the simple addition of the Cu metal to Mo<SUB>6</SUB>S<SUB>8</SUB> electrodes. However, the exact reaction mechanism of the additional reversible capacity for the Mo<SUB>6</SUB>S<SUB>8</SUB> and Cu mixture cathode has not been clearly understood yet. To clarify this unusual behavior, we synthesize a novel Cu nanoparticle/graphene composite for the preparation of the mixture electrode. We thoroughly investigate the electrochemical behaviors of the Mo<SUB>6</SUB>S<SUB>8</SUB> and Cu mixture cathode with the relevant structural verifications during Mg<SUP>2+</SUP> insertion and extraction. The <I>in situ</I> formation of Cu<SUB><I>x</I></SUB>Mo<SUB>6</SUB>S<SUB>8</SUB> is observed, indicating the spontaneous electrochemical insertion of Cu to the Mo<SUB>6</SUB>S<SUB>8</SUB> host from the Cu nanoparticle/graphene composite. The reversible electrochemical replacement reaction of Cu in the Mo<SUB>6</SUB>S<SUB>8</SUB> structure is clarified with the direct evidence for the solid state Cu deposition/dissolution at the surface of Mo<SUB>6</SUB>S<SUB>8</SUB> particles. Moreover, the Mo<SUB>6</SUB>S<SUB>8</SUB> and Cu mixture cathode improves the rate capability compared to the pristine. We believe that our finding will contribute to understanding the origin of the additional capacity of the Mo<SUB>6</SUB>S<SUB>8</SUB> cathode arising from Cu addition and improve the electrochemical performance of the Mo<SUB>6</SUB>S<SUB>8</SUB> cathode for rechargeable Mg batteries.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/aamick/2015/aamick.2015.7.issue-12/am508702j/production/images/medium/am-2014-08702j_0008.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/am508702j'>ACS Electronic Supporting Info</A></P>

Neurological Complications Resulting from Non-Oral Occupational Methanol Poisoning

Choi, Ji-Hyun,Lee, Seung Keun,Gil, Young-Eun,Ryu, Jia,Jung-Choi, Kyunghee,Kim, Hyunjoo,Choi, Jun Young,Park, Sun Ah,Lee, Hyang Woon,Yun, Ji Young The Korean Academy of Medical Sciences 2017 JOURNAL OF KOREAN MEDICAL SCIENCE Vol.32 No.2

<P>Methanol poisoning results in neurological complications including visual disturbances, bilateral putaminal hemorrhagic necrosis, parkinsonism, cerebral edema, coma, or seizures. Almost all reported cases of methanol poisoning are caused by oral ingestion of methanol. However, recently there was an outbreak of methanol poisoning via non-oral exposure that resulted in severe neurological complications to a few workers at industrial sites in Korea. We present 3 patients who had severe neurological complications resulting from non-oral occupational methanol poisoning. Even though initial metabolic acidosis and mental changes were improved with hemodialysis, all of the 3 patients presented optic atrophy and ataxia or parkinsonism as neurological complications resulting from methanol poisoning. In order to manage it adequately, as well as to prevent it, physicians should recognize that methanol poisoning by non-oral exposure can cause neurologic complications.</P>

기준구의 온도 해석을 통한 지상 물체의 표면 온도 예측 기법 연구

최준혁(Jun-Hyuk Choi),길태준(Tae-Jun Gil),김태국(Tae-Kuk Kim) 대한기계학회 2006 대한기계학회 춘추학술대회 Vol.2006 No.6

This paper is aimed at the development of a software that predicts the surface temperature profiles over 3-D objects on the ground by considering the spectral solar radiation through the atmosphere. This software considers the thermal energy balance within control volumes on the reference sphere by considering the direct and diffuse solar irradiance obtained by using the LOWTRAN7. The conduction within the reference sphere is assumed as one-dimensional and the results obtained from the reference sphere can then be used to obtain temperature profiles of the object with more complicated shapes by simply comparing the directions of the surface elements on the reference sphere and the actual object. In this paper, the transient temperature distribution over a cylinder is calculated by using the semi-implicit method. Results obtained by using different numbers of control volumes on the reference sphere are tested to examine the dependency of the C.V. numbers on the final accuracy.