Poly ethylene terephthalate의 저온결정화에 의한 미세구조의 변화

김동건,진영길 경상대학교 농업생명과학연구원 2002 농업생명과학연구 Vol.36 No.4

용융상태로부터 급랭한 PET의 무정형 상태는 용융온도에 크게 영향을 받아 용융온도가 낮은 경우에는 랜덤한 분자쇄 배열보다 결정화가 용이한 무정형구조를 나타내었으며 높은 용융온도에서 급랭한 경우에도 100℃의 저온 열처리에 의해 결정화시키면 부분적으로 분자쇄의 재배열이 일어나 결정화가 용이한 무정형구조로 변화하여 가는 것을 알 수 있었다. 또한, 저온결정화에 의한 발열피크가 열처리에 의해 저온쪽으로 이동하는 현상도 이러한 열처리에 의해 질서가 상대적으로 높은 무정형구조가 되기 때문으로 생각된다. 무정형 PET의 저온열처리에 의한 결정화의 과정은 무정형구조가 부분적 또는 단계적으로 질서화됨으로써 결정화가 이루어진다고 생각된다. Preparing amorphous PET films which were quenched after being melted at various temperature, we examined a change of micro structure by the cold-crystallization using DSC, XRD and TEM. The amorphous PET films quenched from the melting condition were largely influenced by the melting temperature. The PET films showed the amorphous structure that is easier to crystallize than the random molecular chain arrangement under the low melting temperature. Also, in the case of high melting temperature, the PET films were changed into the amorphous structure that is easy to crystallize by the portional rearrangement of molecular chain as a result of the 100 degree low annealing treatment. The phenomenon, the exothermic peaks by"the cold-crystallization move to the low temperature owing to the annealing treatment, can be also explained by the well-ordered amorphous structure by this annealing treatment. A crystallization process of the amorphous PET films by the low temperature annealing treatment is accomplished by the portional and gradual order of amorphous structure.

국악감상수업을 위한 멀티미디어 학습자료개발 : 초등학교 3, 4학년을 중심으로

김동현,채길룡,오한숙 光州敎育大學校 初等敎育硏究所 2002 初等敎育硏究 Vol.17 No.-

Emphasis of Korean classical music has been greatly placed on the music course since the 6th curriculum, and it is more laid in the 7th curriculum; the content is more detailed and Korean classical music of materials in music textbook amounts to 38% - increased 10% compared to the 6th curriculum. Now is rather to devise data to enable 'esthetical experience' of Korean classical music by providing certain 'experience activity' program and develop data to be effectively used in the field than to discuss weight of Korean classical music education. Therefore, this study attempts to develop appreciation data with computer and multimedia to be used as teaching and learning data in the appreciation area, which specially teachers suffer from how to guide, among several areas of Korean classical music. For such objective, the music course of the third and fourth grader was analyzed to draw a teaching and learning objective and a viewpoint of appreciation, materials of Korean classical music were examined in textbook, and various multimedia data and related website to improve teaching effect were surveyed, arranged and made into PowerPoint data. In addition, students' interest in learning and results of the performance evaluation were compared by application of the produced multimedia data to the actual field class to verify effect of data use. As a result of comparison of results of students' interest in Korean classical music appreciation class before and after application of the produced data, use of the data influenced improvement of students' interest in Korean classical music class. Also, as a result of making the field teachers who are interested in Korean classical music class examine the data, they responded that the data is very useful for improvement of the field Korean classical music class. Results of this study are summarized as follows; A. In Korean classical music class, data enabling broad experience and musical practice through application of the varied multimedia dta out of monotonous listening-centered class was developed. B. Out of the limited educational environment by improvement of teaching and learning method with ICT, self-directional learning was enabled in consideration of learner's level and interest.

치아의 발육 및 맹출에 따른 신경지배의 발달

김동길 慶北大學校 齒科大學 1995 慶北齒大論文集 Vol.12 No.2

치아의 발육 및 맹출에 따른 신경지배의 발달을 관찰하기 위하여 출생후 1,5,10,15,20,25,35일 된 백서 및 성장이 완료된 백서 각 5마리씩 총 40마리의 하악 구치를 대상으로 neurofilament protein(NFP)과 calcitonin gene-related peptide(CGRP)의 항체를 이용한 면역조직화학적방법을 사용하였으며 결론은 아래와 같다. . NFP 면역반응 신경섬유보다 CGRP면역반응 신경섬유의 분포밀도가 높게 나타났다. 그러나 NFP 면역반응 신경섬유는 비교적 선이 명확한 외형을 나타내는 반면 CGRP 면역반응 신경섬유는 외형이 거칠면서 염주알 모양을 나타냈다. . 치수내 신경섬유의 진입은 상아질 형서이 시작되는 시기였다. Raschkow plexus는 치근형성시기 부터 발달하여 치아가 구강내로 맹출되면서 보다 발달되었다. 조상아세포층으로 진입하는 신경섬유도 치아가 구강내로 맹출하면서 밀도가 높아졌다. . 치조점막상피의 신경지배는 치아의 발육 및 맹출과 관련하여 발달하였다. 치주인대의 신경지배도 치근 형성과 함께 발달하였다. . 신경지배 발달은 역연령(chronological age)보다 치아연령(dental age)에 따르는 것으로 나타났다. The purpsoe of this study was to investigate the postnatal development of dental innervation with the tooth development and eruption process in developing rat mandibular molars(postnatal 1, 5, 10, 15, 20, 25, 35day-old and adult rats). Immunohistochemical method was carried out for the detection of nerve fibers, using the antibodies against neurofilament protein(NEP) and calcitonin gene-related peptide(CGRP). The results were as follows: 1. The distribution of CGRP immunoreactive(IR) nerve fibers was more densely detected than the NFP-IR nerve fibers. The feature of CGRP-IR nerve fibers were shown in a bead-like appearance and that was more frequently revealed in nerve terminal and immature stages of development. 2. The time of nerve entering into the dental papilla of tooth follicle began at the occured advanced dentinogenesis. The development of Raschkow plexus began at the formative stage of the roots and was accelerated at the stage of the crown emerged into the oral cavity. The number of nerve fibers entering the odontoblastic layer increased with the tooth eruption and mastication. 3. The development of the innervation in the alveolar mucosa was represented associated with dental development and erupiton. The innervation of preiodontal ligament developed according to the eruption of tooth. 4. The development of innervation was shown to be related with the stage of the development of individual teeth rather than the chronological age of the rat.

가토에서 일측 요관 부분 및 완전폐색시 신장과 요관의 조직학적 변화

김상현,김용웅,육승모,한동석,노안식,임재성,김홍식,나용길,설종구 충남대학교 의학연구소 2003 충남의대잡지 Vol.30 No.2

This study was designed to clarify histologic changes in the experimental rabbit kidney and ureter after unilateral partial or complete ureteral obstruction. A total of 20 adult white rabbits were divided into 4 subgroups in the partial obstruction followed by 2 weeks, the partial obstruction followed by 4 weeks, the complete obstruction followed by 2 weeks, and the complete obstruction followed by 4 weeks. The normal control group was consisted of 5 adult white rabbits. The kidneys and ureters for light microscopy were fixed in 10% neutral formalin, embedded in paraffin and stained with hematoxylin and eosin. Abnormal histologic fingings showed in ipsilateral kidney and ureter of all subgroups(such as dilatation of uriniferous tubule, focal necrosis and desquamation of epithelium, interstitial fibrosis, glomerular congestion, widening of Bowman's space, dilatation of ureter, epithelial cell atrophy or loss, interstitial fibrosis and interstitial inflammation). These findings were most severe in the group of the complete-obstructed ureter for 4 weeks. No significant changes showed in contralateral ureter of all subgroups. The degree of obstruction was severe and period of obstruction was long, the histological changes in ipsilateral side were severe. Despite of changes in ipsilateral side no abnormal findings showed in contralateral side. We suggest that long term experimental investigation of histologic changes in ipsilateral side and compensatory changes in contralateral side have to be studied.

출생후 흰쥐 구치의 발육에 따른 치수의 신경지배 발달에 관한 면역조직화학적 연구

김영진,남순현,배용철,김동길,김현정 大韓小兒齒科學會 1996 大韓小兒齒科學會誌 Vol.23 No.4

The purpose of this study was to investigate the postnatal development of pulpal innervation with the tooth development and eruption process in developing rat mandibular molars (postnatal 1, 5, 10, 15, 20, 25, 35day-old and adult rats). Immunohistochemical method was carried out for the detection of nerve fibers, using the antibody against calcitonin gene-related peptide(CGRP). The results were as follows: The feature of CGRP-IR nerve fibers were shown in a bead-like appearance. The time of nerve entering into the dental papilla of tooth follicle began at the occured advanced dentinogenesis. The development of Raschkow plexus began at the formative stage of the roots and was accelerated at the stage of the crown emerged into the oral cavity. The number of nerve fibers entering the odontoblastic layer increased with the tooth eruption and mastication. The development of innervation was shown to be related with the stage of the development of individual teeth rather than the chronological age of the rat.

화상처리에 의한 춉트 스트랜드 섬유배향의 분포측정

김혁,윤성운,한길영,심재기,이동기 조선대학교 생산기술연구소 1995 生産技術硏究 Vol.17 No.2

In order to examine the accuracy of intensity method, the fiber orientation distribution of chopped strand reinforced polymeric composites is measured using image processing. Theoretical and experimental results of fiber orientation function are compared with each other for the composites having different fiber content and fiber orientations. An intensity method is used for the experimental investigation and the measured fiber orientation function is compared to the calculated one. The results show that, firstly, the feature of fiber orientation can be represented and identified by the fiber orientation function J measured and theoretical fiber orientation functions, J_(M) and J, respectively and related as J_(M)=0.73J. Secondly, as far as the measuring of fiber orientation is concerned, the intensity method is, in general, found to be quite effective due to its feature of using the intensity difference in the measuring ranges. Finally, the accuracy of the method increases when the fiber with less clash is considered.

소양호에서 인의 존개 형태별 분포에 관하여 : The Distribution of Phosphorus Fractions in Lake Soyang

김범철,허우명,황길순,김동섭,최광순 江原大學校 附設 環境硏究所 1996 環境硏究 Vol.13 No.-

The distribution of phosphorus in Lake Soyang from January 1985 to August 1992 was surveyed by the measurement of soluble reactive phosphorus(SRP), total dissolved phosphorus(DTP), and total phosphorus(TP) concentration. SRP concentration was in the range of 2~7㎎/㎥ in epilimnion, and 4~200㎎P/㎥ in hypolimnion. The vertical distribution pattern of SRP showed a large difference with the season. SRP concentration decereased during the growing season of phytoplankton in the epilimnion of Lake Soyang and increased in hypolimnion during the oxygen depletion. Higher concentration near the bottom implies they are diffused from the bottom sediment where organic particles are settled and degraded. SRP, DOP, POP and TP concentration was higher in the meralimnion of Lake Soyang in rainy season It might be related with storm runoff. General trend of TP variation is that the TP concentration of water column is increasing substantially from yeat to year. TP concentration in the surface water increased from 5㎎P/㎥ at 1985 to 20㎎P/㎥ at 1992.

용접비드 형상예측 시스템 개발에 관한 연구

김일수,손준식,박창언,서주환,장경천,이동길 朝鮮大學校 機械技術硏究所 2005 機械技術硏究 Vol.8 No.2

Generally, the use of robots in manufacturing industry has been increased during the past decade. GMA(Gas Metal Arc) welding is an actively growing area and many new procedures have been developed for use with high strength alloys. One of the basic requirement for welding applications is to study relationships between process parameters and bead geometry. The objective of this paper is to develop a new approach involving the use of neural network and multiple regression methods in the prediction of bead geometry for GMA welding process and to develop an intelligent system that enables the prediction of bead geometry using Rapid Prototyping(RP) in order to employ the robotic GMA welding processes. This system developed using MATLAB/SIMULINK, could be effectively implemented not only for estimating bead geometry, but also employed to monitor and control the bead geometry in real time

수분흡수가 섬유강화 고분자 복합판의 기계적 성질에 미치는 영향

김혁,한길영,이동기 조선대학교 생산기술연구소 1995 生産技術硏究 Vol.17 No.1

Nowadays, it is common and becoming more popular to use fiber-reinforced polymeric composites(FRP) in order to reduce the lightweight of the structures such as marine vehicles, automobiles and airplane. It investigates the residual strength characteristics of composite under the environment of high temperature and humidity. The residual strength of FRP is known to be greatly influenced by temperature, humidity etc. In this context, the hygrothermal effect of changing the fiber contents and orientation are investigated in order to provide better residual strength characteristics. When exposed long terms in high temperature and humidity, the randomly oriented composites is to be more stable than the unidirection one.

관동맥 우회로술 중 경식도 심초음파도로 관찰한 도부타민 투여후와 우회로술후의 좌심실 국소벽운동

김희열,김종진,윤호중,유기동,박지원,이길환,노태호,채장성,김재형,홍순조,최규보 대한순환기학회 1997 Korean Circulation Journal Vol.27 No.8