유사체액에서의 전기화학적 처리가 티타늄 표면의 인산갈슘 흡착에 미치는 영향

조국현,김문영,송광엽,배태성,이민호 大韓齒科器材學會 2002 대한치과재료학회지 Vol.29 No.3

This study was performed to examine the effect of electrochemical treatment on the precipitation of apatite-like calcium phosphate in a simulated body fluid. Titanium plates of 20×20×1 ㎣ in dimensions were polished sequentially from #600 to #2,000 emery paper and one surface of each specimen was received an additional polishing sequence through 0.1㎛ alumina paste. To improve the bioactivity of titanium plates, they were electrochemically treated at 100 mA for 20 min in an electrolyte containing the calcium and phosphate ions, and the Hanks' solution with pH 7.4 at 36.5℃ for 30 days, and the surfaces were examined with X-ray diffractometer(XRD), scanning electron microscope(SEM) and X-ray photoemission spectroscopy(XPS). Precipitation of calcium phosphate and CaO were observed on the electrochemically treated titanium surface in a simulated body fluid after treatment at 600℃. Precipitation of calcium phosphate was densified and coarsened with increasing the temperature of the electrolyte solution in the range of 20-80℃. The calcium phosphate contained phosphate in the form of Po₄^3-, HPO₄^2-, and H₂PO₄^-.

韓國人에서 多重增幅 重合酵素反應으로 分析한 STRs 遺傳座位의 遺傳的 多樣性

권국환,이혜린,박종진,황적준,이희석,송은섭 大韓法醫學會 1996 대한법의학회지 Vol.20 No.1

The tetrameric STRs loci were studied in a population of Korean(n=223) for allele frequency distribution and applicability to identity and paternity testing, using multiplex PCR with electrophoresis of the PCR products in DNA sequencing gels and subsequent detection of allelic fragments by silver staining. The STRs loci analyzed were HUMCSF1PO, HUMTPOX, and HUMTHO1 ; in the Korean population, 9 alleles with their frequency range of 0.002-0.363 are detected in the HUMCSF1PO, 5 alleles with those of 0.020-1.480 in the HUMTPOX, and 6 alleles with those of 0.002-0.489 in the HUMTHO1. The highest observed heterozygosity is found at the locus HUMCSF1PO(0.709), those of the loci HUMTPOX and HUMTHO1 being 0.646 and 0.632, respectively. All loci meet Hardy-Weinberg expectations ; there are good agreement between the observed and expected values under Hardy-Weinberg equilibrium. Moreover, pairwise comparisons between loci show allelic independence for all the 3 loci comparisons. The power of discrimination (PD) determined for the locus HUMCSF1PO is 0.8896 (88.96%), that of the HUMTPOX is 0.8818(88.18%), and that for the HUMTHO1 is 0.8367(83.67%) ; the combined power of discrimination for the triplex is 0.9976(99.76%). The power of exclusion(PEX) calculated for the loci HUMCSF1PO, HUMTPOX, and HUMTHO1, being prior probability that a falsely accused father will be excluded, and 0.5173(51.73%), 0.4610(46.10%), and 0.5101(510.01%), respectively, and the cummulative power of exclusion(CPE) for all the three loci is 0.8726(87.26%). Thus, these allelic frequency data can be used to construct the database of the multiplex PCR-based DNA profile in the Korean population. The calculated parameter, "power of discrimination(PD)" and "power of exclusion(PEX)", show the informativeness of these loci for the determination of identity and relatedness of individuals.

연속류 반응조에서 간헐 포기 도입의 효과

장국안,송창수 호남대학교 2000 호남대학교 학술논문집 Vol.21 No.2

Results of our trials demonstrate that the alternating aerobic/anaerobic conditions is capable of producing effluent of high quality in continuous systems. Inducing the alternating conditions, the high oxygen transfer rate is occurred during changes between the anaerobic conditions and aerobic conditions. Due to high oxygen transfer rate, the removal rate of BOD and phosphorous is higher than the general process. The alternating system is brought about the separating the nitrifying microorganism from heterogenous microorganisms and induced the high rate nitrification.

COX 모델을 이용한 생존자료분석에서 Proportionality 가정 검정의 의의

이무송,유근영,노동영,최국진 대한암학회 1991 Cancer Research and Treatment Vol.23 No.4

CUG에 의한 원거리정보통신망 구축과 활용:국제종합건설 사례

이국희,송수섭 한국데이타베이스학회 1994 Journal of information technology applications & m Vol.1 No.2

송전선로 보호계전기 정정값 진단 시스템

이승재,김국진,최면송,강상희 明知大學校 産業技術硏究所 2000 産業技術硏究所論文集 Vol.19 No.-

In the point of view a protective relay, the selectivity and sensitivity is very important in its performance. The correct setting of the relay parameter is required. The verification of accurate setting for the protective relay is very difficult before a actual fault occur. In this paper, we proposed the diagnosis expert system as a method to verify the correctness of the relay setting. The developed system proved effectiveness through the tests on the real systems.

중학교 과학 교과서 분별 증류 실험의 비교 분석 및 개선

柳五鉉,崔文永,宋周眩,권정근,白盛惠,朴國泰 한국교원대학교 과학교육연구소 2001 청람과학교육연구논총 Vol.11 No.1

이 연구의 목적은 제 6차 교육과정에 의한 중학교 1학년 과학 교과서 분별 증류 실험의 문제점을 파악하고, 중학생들이 분별 증류 실험을 능률적으로 수행할 수 있는 실험 방법을 제시하고자 하는 것이다. 이를 위한 첫 번째 단계로서 현재 사용되고 있는 8종의 과학 교과서를 분별 증류 실험 장치와 액체 혼합물의 종류에 따라 6가지로 분류하였다. 두 번째 단계로서 액체 혼합물을 가열 방법에 따라 직접가열과 물 중탕 가열로 나누어 교과서 실험과정에 따라 같은 실험을 세 번 실시하였다. 세 번째 단계로서 실험 결과의 문제점을 해결하기 위한 대안 실험을 실시하였다. 대안 실험에서는 알코을 램프로 직접가열 하는 방법과 기름 중탕으로 가열하는 방법, 그리고 가열 맨틀을 사용하여 가열하는 방법을 사용하였다. 연구결과, 가지 달린 둥근 플라스크를 직접 가열하는 실험 결과가 가지 달린 시험관을 물 중탕으로 가열하는 실험 결과보다 이론적인 결과에 근접하였다. 그리고 가지 달린 둥근 플라스크를 직접 가열하는 실험에서 플라스크 윗 부분을 보온해 주는 실험이 보온하지 않은 실험보다 실험 결과가 더 나았다. 대안 실험에서는 액체 혼합물의 증류 온도 증가를 보면서 가열 맨틀의 가열 온도를 을려 준 실험의 결과가 이론적인 결과에 가장 가까웠다. 이러한 연구 결과로부터 가지 달린 시험관을 물 중탕으로 가열하는 분별 증류 실험 장치는 탐구실험 수업에 부적절한 것이므로 개선이 요구되며, 중학교 과학실 여건을 고려할 때, 액체 혼합물의 증류 온도 증가를 보면서 가열 맨틀의 가열 온도를 변화시키는 분별 증류 실험이 가장 능률적인 방법임을 알 수 있었다. The purpose of this study was to find out the problems on the fractional distillation experiments in the middle school science textbooks based on the 6th curriculum and to suggest an efficient experiment method for the middle school students. The first step was the classification of the experiments in 8 science textbooks according to heating apparatus and liquid mixtures. The second step was doing each experiment 3 times followed by the experimental process in the textbooks. The third step was developing the alternative experiments for solving the problems found in the second step. The heating method used in the alternative experiments were direct heating, oil bath, and heating mantle. The results of the second step showed that the direct heating experiment of branched round flask was more close to the theoretical prediction than the experiment of water bath heating of branched test tube. Also the direct heating experiment of thermally insulated branched round flask was better than the result of the experiment which was not insulated. The results of the third step showed that the experiment using heating mantle regulated heating power by observing the temperature of distillate gave the closest result to the theoretical prediction. From the above results, it is concluded that the experiment using branched test-tube with water bath heating is not adequate for the fractional distillation and an alternative experiment using insulated branched round flask with heating mantle regulated heating power during experiment is recommended.

동적 채널 할당을 윈한 무선 중계 시스템

장자영,노순국,김송민,김재섭,허영팔,박창균 조선대학교 동력자원연구소 1997 動力資源硏究所誌 Vol.19 No.1

Being adopted the Cellular Systems in Korea, the method of a radio repeater is that the mobile station(MS) can be used only in a service area of the base station(BS). In case that traffic congestion is occured around the specific BS because of an event etc., the traffic blocking rates are being maximized and the subscriber service is being dropped. To improve these problems, we propose an algorithm for a radio repeater network that distributes the traffics of the specific BS, predicted traffic congestion, to an adjacent BS by sharing a service area. And then, we confirm the valid through the simulation.

Enhancement of Grain Refinement and Mechanical Properties of Cross-Roll Rolled Pure Copper

Song, Kuk Hyun,Kim, Han Sol,Kim, Won Yong The Japan Institute of Metals 2011 Materials transactions Vol.52 No.5

<P>The aim of this work was to evaluate the effects of strain rate on the microstructural evolution of 5-mm-thick pure copper (99.99%) sheets subjected to conventional rolling (CR) and cross-roll rolling (CRR). The sheets were cold-rolled with a reduction ratio of 90% and then annealed at 400°C for 30 min to obtain the fully recrystallized microstructures. The resulting cold-rolled and annealed sheets had considerably finer grains than the initial sheets. In particular, the average grain size became smaller by CRR (6.5 μm) than by CR (9.8 μm). The mechanical properties of the sheets, i.e., Vickers microhardness and tensile strength, were more enhanced by CRR than by CR. The microstructural development in these processes was systematically discussed.</P>

Origin and Fate of Pendrin-Positive Intercalated Cells in Developing Mouse Kidney

Song, Hyun-Kuk,Kim, Wan-Young,Lee, Hyun-Wook,Park, Eun-Young,Han, Ki-Hwan,Nielsen, Soren,Madsen, Kirsten M.,Kim, Jin American Society of Nephrology 2007 Journal of the American Society of Nephrology Vol.18 No.10

<P>Pendrin is an apical anion exchanger found in type B and nonA-nonB intercalated cells that is involved in bicarbonate secretion. The purpose of this study was to establish the origin and fate of pendrin-positive intercalated cells in the mouse kidney. Using immunohistochemistry, we found that pendrin-positive cells first appeared in the connecting tubule at embryonic day 14 (E14) and subsequently in the medullary collecting duct at E18. Most of the pendrin-positive cells in the connecting tubule were nonA-nonB intercalated cells, wheras those in the medullary collecting duct were type B intercalated cells. In the cortical collecting duct, pendrin-positive cells appeared in the inner part at day 4 after birth and in the outer part at day 7. Pendrin-positive cells gradually disappeared by apoptosis from the inner part of the medullary collecting duct two weeks after birth. Using 5-bromo-2'deoxy-uridine (BrdU) to follow cell proliferation, we determined that selective proliferation of pendrin-positive intercalated cells does not occur; instead, these cells may arise from undifferentiated precursor cells from separate foci, one in the connecting tubule and one in the collecting duct.</P>