수종 유기산 용액에서 글라스 아이오노머 시멘트의 표면조도 및 색 변화에 관한 연구

김용대,문현정,임범순,김철위 대한치과기재학회 1997 대한치과재료학회지 Vol.24 No.2

The chemical bonding ability of glass ionomer cement to tooth structure and sustained fluoried release render glass ionomer cements advantageous over other restorative materials, such a amalgam and composite resins. Poor polishability and high solubility in organic solvents, however, are still a significant disadvantage of the existing glass ionomer cements. The purpose of this study was to estimate the aging effect of glass ionomer cements in organic acid solutions on surface change and color change. Using metal molds, disk type speciments, 100mm×1mm were prepared from three chemical-curing and three light-curing glass ionomer cements. Specimens were prepared from each material following the manufacturer's intructions, and setted against a mylay matrix strip supported by a glass slab. Three specimens were prepared for each experimental groups. Profilometric analyses were carried out using the surface roughness tester(Surtronic 3P, Rank Taylor Hobson Ltd. England). R?? valuse, which were the mathematical mean values of the departure of the roughness profile from the mean line calculated by the machine, recorded. Color measurements(CIE coefficients ; L, a, b) were peformed using the spectrophotometer(CM-3500d, Minolta, Japan). Before aging treatment and after 1, 7, 14, 21, and 28 days aged at 37℃ in a various organic and solutions(such as acetic acid, lactic acid and citric acid) and deionized water, surface roughness and color coefficients measuements were carried out. Then, surface roughness changes(ΔRa) and (ΔE) of specimens were calcuiated. From the experiment, the following results were obtained : 1. Chemical-cured glass ionomer cements showed statistically surface roughness changes after aged in the deionized water(P<0.10), and light-cured glass ionomer cements showed statistically significant color changes after aged in the deionized water(P<0.10). 2. Chemical-cured glass ionomer cements showed statistically color changes after aged in acetic acid solutions (P<0.10), and light-cured glass ionomer cements did not showed statistically significant surface roughness changes, but showed statisticall significant color changes after aged in acetic acid solutions (P<0.10). 3. Chemical-cured glass ionomer cements did not showed statistically significant color changes as a function of concentration of lactic acid solutions (p>0.10), and light-cured glass ionomer cements showed statistically significant color changes after aged in acetic acid solutions. 4. Chemical-cured glass ionomer cements did not showed statistically significant surface roughness changes as a function of concentration iof lactic acid solutions (p>0.10), but showed significantly less solubility in lactic acid solutions than chemical-cured glass ionomer cements.

상아질 표면처리제 및 결합제가 레진강화형 글라스 아이오노머와 상아질의 전단결합강도에 주는 영향

김용대,이용근,임범순,김철위 대한치과기재학회 2000 대한치과재료학회지 Vol.27 No.4

Resin-modified glass ionomers (RmGIs) have been widely used and are recommended for restoring cervical lesions that include enamel and dentin margins, and for caries-prone patients because of the possible anticariogenic effect of fluroride. The purpose of this study was to evaluate the shear bond strength of two resin-modified glass ionomers to dentin using four different dentin surface treatments and two one-bottle bonding agents. Human dentin was pretreated with 35 % phosphoric acid, 10 % citric acid and 3 % ferric chloride, 10 % polyacrylic acid and EDTA 3-2 solution, and was applied with One-Step and Single Bond. Two resin-modified glass-ionomers, Fuji Ⅱ LC(FLC) and Vitremer (VTM), were then adhered to the dentin. After 24 h in distilled water at 37 ℃ the shear bond strength between the resin-modified glass-ionomers and the pretreated dentin was measured with an Instron at a crosshead speed of 0.5 mm/min and the dentin-dentin bonding agent-RmGI interface of the specimen was observed by SEM. From the experiment, the following results were obtained : 1.For the dentin treated only with surface treatments except EDTA 3-2 solution, the shear bond strength of resin-modified glass ionomers to dentin was statistically significant higher than that of resin-modified glass ionomers to dentin treated with dentin surface treatments (p<0.05). 2.For the dentin applied with dentin bonding agents subsequent to pretreatment with dentin surface treatments, the shear bond strength of resin-modified glass ionomers to dentin was statistically significant higher than that of resin-modified glass ionomers to dentin treated only with dentin surface treatments (p<0.05). 3.When the specimens were applied with One-Step or Single Bond subsequent to four different dentin surface treatments, the shear bond strength of resin-modified glass ionomers to dentin was not statistically different between One-Step and Single Bond (p<0.05). 4.With applications of dentin bonding agent, 35 % phosphoric acid or 10 % citric acid + 3 % ferric chloride solutions were found to be the most effective in improving bond strength to dentin, followed by 0.5 M EDTA 3-2 solution and 10 % polyacrylic acid solution. 5.From SEM observations, 10 % polyacrylic acid solution did not completely remove the smear layers, but 35 % phosphoric acid, 10 % citric acid + 3 % ferric chloride, and 0.5 M EDTA 3-2 solution completely removed the smear layers so that could form resin tag.

TCP 혼잡 제어를 위한 동적 RED 알고리즘

김대영,김은범,안기중 제주대학교 공과대학 첨단기술연구소 2002 尖端技術硏究所論文集 Vol.13 No.2

Recently many studies have been done on the Random Early Detection as an active queue management and congestion avoidance scheme in the Internet. The AQM(Active Queue Management) of traffic congestion involves the policy which drops a packet for congestion avoidance. In this case, router drops one or more packets to improve the network performance before when the output buffer becomes full. In this paper, we overview the characteristics of the RED and the modified RED algorithms in order to understand the current status of these studies. Based on the RED parameter analysis, we propose a Dynamic RED Algorithm for Active Queue Management scheme to cope with this RED weakness. In this algorithm we make three parameters be adjusted depending on the queue status.

조기유자망 어구의 개량 및 생력화 조업시스템 개발 : 3. 생력형 5단 양망기의 해상 성능 시험

김석종,구명성,강경범,서대범,정용진 제주대학교 해양과환경연구소 2005 해양과환경연구소 연구논문집 Vol.29 No.2

스포츠 외상에 의한 척추·척수손상 분석

김대경,임완기,임정일,김범수,추해광,강은균 한국스포츠리서치 2004 한국 스포츠 리서치 Vol.15 No.2

I have researched 46 examples, 43 are spinal column and cord injury and 3 are thoracic vertebrae and cord injury, of J hospital S health caring center. 46 patients were cured by this J hospital medical staffs, and their external injury were caused by sports accidents. I have acquired next four meaningful conclusions. First, the external injury caused by golf sports are 24 cases, and this is the primary cause of injury. Second, high-rank bonn fracture are 78.8 percent in C4, C5, C6 situation. And the bone-fracture, tear-drop fracture, figure in the activity of gold is 45.8 percent, and fracture dislocation is 63.2 percent in other sports activities. Third, there are twenty six cases of paralysis that links frankel C. Four, the sports injuries such as bone fracture are able to prevent by education and effective learning programs.

기체 방사성 물질 제거를 위한 첨착 활성탄 필터 시스템 성능에 관한 연구

김대욱,손현철,이명석,이석범,박길문 朝鮮大學校 機械技術硏究所 1999 機械技術硏究 Vol.2 No.1

This paper presents an application of impregnated activated carbon and impregnated activated carbon filters. They are used for the removal of gaseous radioactive materials at radioactive material handling facilities such as nuclear power plants and research facilities. High adsorption efficiencies as well as stability are required for them to remove hazardous radioactive gases such as activated free iodine released during normal operation or accident condition. This research was initiated to enhance the independence of nuclear industry and raise the level of nuclear technology to that of the leading nuclear nations. By attaining the capability of design and development of HVAC system, national technological competitiveness can be achieved. Also, the ground for technology export will be hardened. Therefore, it is well timed to initiate the project to develope those filter systems domestically utilizing all the relevant technologies available.

링 공진기 필터를 이용한 UWB 펄스의 생성

金範柱,金東昊,朴鍾大 明知大學校 産業技術硏究所 2006 産業技術硏究所論文集 Vol.25 No.-

In this paper, we generated UWB(Ultra wideband) pulse using a ring resonator structure with stub. The ring filter is made to control the attenuation pole frequency. A five stage UWB filter is fabricated, Fabricated filters passband was 3.1-10.6GHz and having notch frequency at WLAN(Wireless LAN) band. Measured pulse is notched WILAN with 5GHz out efficiently, it verified 600psec of pulse width, 11mVp-p of amplitude, and pulses shape is high order derivative gaussian pulse.

농부가 아닌 환자에서 발생한 긴털가루진드기(Tyrophagus Putrescentiae)에 의한 기관지천식 1례

최대로,김형수,고창옥,김희선,윤호성,박용범,김상훈,이재영 대한천식 및 알레르기학회 2004 천식 및 알레르기 Vol.24 No.1

Storage mites are believed one of the most important allergens in farmers and rural regions. Tyrophagus putrescenitiae, belonging to storage mites, is found not only within storehouses but also in the house dust, and the third most common mites following Dematophagoides farinae and Dermatophagoides pteronyssnus in house dust in Korea. The sensitization rate to Trophagus putrescentiae was reported as high as that of house dust mite in patients visiting the allergy clinic in large cities in Korea. We experienced a 69-year-old man who had suffered from dyspnea, wheezing, and coughing for 10 years. He retired from the teaching profession, and had lived in a large city. Deajeon. The skin prick test showed a positive reaction to Tyrophagus putrescentiae and negative reactions to house dust mites. The bronchial challenge test with Tyrophagus putrescentiae showed late asthmatic reaction. We confirmed a Tyrophagus putrescentiae induced asthma in non occupational setting. (J Asthma Allergy Clin Immunol 24 : 141-5, 2004)

제주지역 만성 B형 간질환 환자에서 임상 양상에 따른 HBV 유전자형의 분포

송병철,김범준,정주영,염충호,이대호,김진석 제주대학교 생명과학연구소 2003 제주생명과학연구 Vol.6 No.1

Background/Aims: The genotype of HBV has been suggested to correlate with the clinical outcome of HBV infection. We analyzed the distribution of HBV genotype according to the clinical outcome of HBV infection in Jeju island. Methods: A total of 145 HBsAg-positive samples were enrolled. To identify specific patterns of HBV genotypes, we performed restriction fragment length polymorphism (RFLP). If typical restriction pattern of RFLP was not determined, phylogenetic analysis was performed. Results: RFLP analysis was possible in 65 patients. Clinical diagnoses of the 65 patients with chronic liver disease were as follows: HBeAg-positive healthy carrier (HBeAg+, anti-HBe-, HBV DNA+, transaminase normal: n=20): HBeAg seroconversion (n=12): chronic hepatitis B (n=14): liver cirrhosis (n=9): hepatocellular carcinoma (n = I0). Sixty-two patients showed typical restriction pattern by HinfI. However, 3 patients showed unique restriction pattern by HinfI, which were not reported in literature. When phylogenetic analysis was performed to classify the genotype of these 3 patients, they were also genotype C. Whereas, all patients showed typical restriction patterns by Tsp509l, which were reported in genotype C. Conclusion: All chronic HBV infection are genotype C in Jeju island regardless of clinical outcome.

Saccharomyces cerevisiae에서 Trichoderma Endoglucanase의 발현과 분비

남수완,김병우,신동하,김재범,신지원,정대균,정춘수 동의대학교 기초과학연구소 1999 基礎科學硏究論文集 Vol.9 No.1

The endoglucanase gene, egl6, of Trichoderma sp. was connected with the yeast ADH1 promoter, and the resultant plasmid, pVT-C4, was introduced into three S. cerevisiae host strains (YNN27, 2805, and SEY2102). Among each 80 transformants, the cell growth and expression level of endoglucanase were compared in test-tube cultivation, and three respective transformants for each host cells showing the highest expression level and cell growth were selected. When three recombinant yeast cells were batchwise cultivated for 48 hr in flask, the total activities of endoglucanase expressed were about 1140 unit/1 with 2805/pVT-C4, 1020 unit/l with SEY2102/pVT-C4, and 590 unit/l with (YNN27/pVT-C4. Irrespective of host strain, about 80% of the expressed endoglucanase was detected in the extracellular medium. In addition, it was also found that the recombinant enzyme was secreted into the culture medium as two major forms of lightly and heavily glycosylated proteins.