RUS법에 의한 Micro-Crack을 가진 Ferrule의 주파수 특성 평가

백경윤,이길성,양순호,김성훈,조영재,민한기,양인영 朝鮮大學校 機械技術硏究所 2003 機械技術硏究 Vol.6 No.2

광섬유 정렬부품으로 사용되는 페롤은 극히 높은 정밀도를 요하는 제품으로서, 높은 치수 정밀도와 결함이 포함되지 않는 등 높은 신뢰성이 요구되는 제품이다. 이러한 페롤의 형상결함평가에 종래의 광학현미경 평가법과는 달리. 본 논문에서는 공명초음파법(ResonantUltrasound Spectroscopy)을 이용하고자 한다. 공명초음파법이란 결함이 없는 시험편을 기계적으로 진동시켰을 때의 공진 주파수와 시험편 내에 결함을 가지고 있을 때의 공명 주파수 양상을 비교 분석하여 결함유무를 검출해내는 방법이다. 본 연구에서는 양품과 크랙을 가진 시험편을 현장에서 직접 사용되고 있는 광학현미경에 의해 분류를 한 다음, 더욱 정확한 측정을 위해 SEM에 의해 다시 분류하였다. 각각에 대해 공진 주파수를 측정하였고, 이 데이터의 검증을 위해 FEM해석을 수행하였다. 실험으로부터 얻는 양품의 공진 주파수와 FEM해석을 통해 얻었던 양품의 공진 주파수의 오차는 1∼2%정도의 범위를 벗어나지 않음을 알 수 있었다. 또한 크랙에 대한 공진 주파수를 측정하여서, 양품의 공진 주파수와 비교를 행하였고, 이 데이터를 가지고 모드별로 히스토그램을 그려서, 그것으로부터 현장에서 실제로 이용 가능한 모드를 존재함을 확인하였다. The Ferrule which is used as the product optical fiber very precisely, is required high to set the optical axes of an dimensional precision, lack of defect and high expectation. Up to now the optical instrument has been used for the defect and shape inspection of the Ferrule, but in this paper we examined the detectable defect and expectation by using the Resonant Ultrasound Spectroscopy (RUS). The RUS is the measurement' which is to excite specimen and to inspect the difference of natural frequency pattern between acceptable specimen and specimen has some defects. In this paper, we classified specimens into three groups by using She optical instrument; acceptable specimen A-type, 3-type and specimen A-type which has crack. And we reclassified by Scanning Microscope to carry out the more exact measurement. We surveyed the resonant frequency of every specimen, and carried out the simulation from the explicit finite elements code, NasEran t o verify the experiment data. The average error between the resonant frequency of acceptable specimens which is obtained from experiment and that from FEM analysis is in the range of 1-2 percentage. Also, we measured the resonant frequency of specimen which has crack, and compared that of acceptable specimen. We drew histogram by using these data, and confirmed the available mode in the plant.

직장암에서 수술 전 방사선-화학요법 후 발생한 후기 합병증

이승현,이철민,안병권,백승언 고신대학교 의과대학 2011 고신대학교 의과대학 학술지 Vol.26 No.1

OBJECTIVES: To compare the late complications after operations for rectal cancers with and without preoperative chemoradiation. METHODS: From January 2003 to December 2005, 55 patients underwent operation after preoperative chemoradiation for adenocarcinoma of the rectum. All of them received the full scheduled dose of radiation with concurrent chemotherapy. The interval between preoperative chemoradiation and surgery was 4-6 weeks. 47 patients who had tumors below 8 cm from the anal verge were enrolled into the study group (CRT group). During same period, we selected 153 patients who had adenocarcinoma of the rectum below 8cm from the anal verge, underwent surgery alone without postoperative radiotherapy non-CRT group). We compared the early and the late postoperative complications between the CRT group and the non-CRT group. RESULTS: Of the late complications, the incidence of anastomotic stricture was significantly higher in the CRT group (P = 0.018). The incidence of anal stricture was higher in the CRT group (P = 0.164). In the CRT group, 3 cases (17.6%) had failed to preserve the anal function due to moderate or severe anal stricture. Of the 3 cases, protective ileostomy was persistent in 2 cases, colostomy was performed in one case. Otherwise, the late complications of the CRT group were intestinal obstruction in 2 cases (4.3%), lymph edema in 2 cases (4.3%). CONCLUSION: In CRT group, failure of anal function preservation due to anastomotic stricture or anal stricture was more common and serious than non-CRT group. We emphasize the need for careful management for postoperative anal stricture after preoperative chemoradiation.

생체분해성 안과제형의 안구내흡수정도와 안독성

민병무,김용백,박근성,송규상,양준묵,이성복,조항진,길숙종,김승영,김학용 충남대학교 의과대학 지역사회의학연구소 1998 충남의대잡지 Vol.25 No.1

An improved retinal tack can be used to fix the retina in complicated retinal detachment and proliferative vitreoretinopathy. We used the retinal tack made by biodegradable polyglycolic acid, polylactic acid and copolymers. The tacks with polyglycolic acid were placed in the retina the right eyes of 10 rabbits as group 1, with polylactic-polyglycolic acid copolymers as group 2 in each left eyes. We examined the absorption rates and degree of intraocular inflammation at 1 day, 1, 2, 4, and 8 weeks and compared both eyes. The tacks were absorbed with time in both eyes, but more rapid in copolymers. And there was no inflammation in both eyes. Now, this study will be a base on the drug delivery system in intraocular pharmacological and surgical management.

생체분해성 고분자를 이용한 사시수술용 제형개발 및 효용성에 대한 연구

민병무,김용백,김승영,김창식,박근성,길숙종,조항진,이성복,노승무,송규상,강대영,조준식,양준묵,정경수,최선웅,이진호,김학용,인현빈 충남대학교 의과대학 지역사회의학연구소 1998 충남의대잡지 Vol.25 No.1

A new device, muscle clamping system was developed to facilitate exact quatifying technique A strabismus surgery, and reduce the risk of complications. The device is composed of a lower fixing body with three jaws and an upper supporting body. They are used to clip an extraocular muscle and fix it to the sclera with a single bite. Superior rectus recession on 16 rabbit eyes were performed with this new device. Conjunctival injection, muscle adhesion strength, and light microscopic findings were examined at 1, 2, 4 and 8 weeks postoperatively. The Conjunctival injection were minimal, adhesion power ranged from 420 to 600 gram gravity, which is sufficient in withstand the normal pull of human extraocular muscle. In microscopic exam, some Inflammatory cells and fibrosis were found. The new device was technically easy, fast, and accurate, so it may be useful in stabismus surgery.

포스포닐화된 어택틱 폴리프로필레수지에 의한 금속이온의 흡착에 관한 연구

백승화,이수민,오인교 圓光大學校 1981 論文集 Vol.15 No.1

The adsorption of metal ions by chelating agent-loaded resins was studied in aqueous media. The resins were prepared by loading the conventional cation exchange resin, coated glass powder by pohsphonyl atactic polypropylene resin(200 to 250 mesh) with chelating agents containing hydroxyl groups. The composition of synthetic resins was analyzed by infrared absorption spectroscopy and also discussed. The optimum conditions for the adsorption of metal ions were determined with respect to the shaking time, the effect of cation concentration and the effect of adsorption of capacities on the industrial waste water in the medium.

공명초음파분광법을 이용한 광컨넥터용 결합소자의 비파괴 검사

김성훈,조영재,백경윤,양순호,민한기,양인영 朝鮮大學校 機械技術硏究所 2004 機械技術硏究 Vol.7 No.1

본 연구의 목적은 비파괴 평가방법인 공명초음파분광법(RUS)을 사용하여 세라믹제 페롤과 볼렌즈의 결함과 형상오차를 평가하는 것이다. RUS시스템은 스펙트럼에너라이저,파워 엠플리파이어,압전진동자센서와 지지프레임으로 구성되어진다. RUS 시스템에 의한 페롤과 볼렌즈의 비파괴평가를 위해 본 연구에서는 각 시험편에 대한 공진주파수를 측정하였으며,측정된 공진 주파수의 비교분석에 의해 결함의 유 · 무를 판별하였다. 그 결과 페롤의 경우,크랙을 갖는 페롤의 공진주파수 대역이 양품페롤의 공진 주파수 대역보다 고주파대역으로 이동함을 알 수 있었으며,볼렌즈의 경우,시험편 질량이 감소함에 따라 공진주파수 대역이 고주파 대역으로 이동함을 알 수 있었다. 또한 볼렌즈의 공진주파수가 측정되는 대역을 예측할 수 있는 파라메타인 β를 설정하여 그 결과를 고찰하였다. The objective of this paper is to evaluate the defect and shape error of a ceramic ferrule and ball lens by Resonant Ultrasound Spectroscopy(RUS) method. RUS system is consisted of spectrum analyzer, power amplifier, PZT sensor, and support frame. For nondestructive evaluate by using RUS system, first of all, we measured the natural frequency of each specimen, and we decided on the shape and size of flaw by measured natural ferquencies. And then, in the case of ferrule, natural frequency bandwidth of ferrule with crack was higher than acceptable ferrule. As mass of ball lens decreased, natural frequency bandwidth was shifting to high-frequency range. Thus, we discussed on the relationship between β and mass of ball lens, which β is parameter that we can predict measurable natural frequency bandwidth of ball lens.

생체분해성 망막압정을 이용한 망막고정에 대한 실험적 연구

김용백,민병무,김창식,박근성,김승영,길숙종,조항진,이성복,노승무,송규상,강대영,조준식,양준묵,정경수,최선웅,이진호,김학용,인현빈 충남대학교 의과대학 지역사회의학연구소 1998 충남의대잡지 Vol.25 No.1

Biodegradable retinal fixation devices obtain mechnical fixation of the retina with desirable chorioretinal scarring and with the potential for local, sustained release of antimetabolites and steroids to inhibit proliferative vitreoretinopathy. We manufactured a biodegradable retinal tack with barb that was designed in order to prevent intrusion from implantation of retinal tacks. This study was carried to evaluate the efficacy for retinal fixation and the capability for sustained release of drugs with a newly designed biodegradable retinal tack Biodegradable retinal tacks were made of polymers of glycolic acids and were designed with barbs in a shape to prevent the disinsertion. Biodegradale retinal tacks are divided into 3 parts, a conical portion that is inserted into the sclera, a cylinder portion that remains in the vitreous, and a neck portion between the pin and the cylinder. The tapered conical end was manufactured to allow easy insertion through the retina and choroid into the sclera. A cylinder portion was manufactured with a tapered angle that fixes firmly into the orifice of 19 gauge spinal needle. A neck portion, 0.4 mm in diameter, was designed to prevent disinsertion from following implantation of retinal tack. The applicator was a 19 gauge spinal needle and its orifice was prepared to 15°angle to accept the tapered cylinder portion of the retinal tack. The retinal tacks, secured in the needles, were passed through the formed vitreous and inserted into the retina, choroid, and sclera and were released by pushing the internal needle, usually within 2-3mm of the medullary ray of the posterior rabbit retina A retinal tack was placed in each of 8 pigmented rabbit eyes. Slit-lamp biomicroscopy, indirect ophthalmoscopy and fundus photography were performed periodically from 1 day to 8 weeks after surgery. Eight eyes were enucleated and studied by light microscopy at 8 weeks. Biomicroscopic evaluation of the animals revealed edemas adjacent to the retinal surfaces immediately after insertion of the biodegradable retinal tacks in all the animals. These edemas disappeared after 1 week. The first noticeable change in the size of retinal tacks was shown after 2weeks. The size of the retinal tacks gradually got smaller, decreasing to about one-half at 4 weeks and about one-third at 8 weeks. All retinal tacks remained in inserted places without any movement for an 8 week period. On light microscopy, epiretinal proliferations were seen to extend into the vitreous cavity. Cellular capsules that lined the inner aspect of the scleral defect caused by tack insertion were found. However the adjacent retina had a normal cytologic appearance and architecture in all specimens. We manufactured a biodegradable retinal tack that is designed to prevent intrusion from implantation of retinal tacks. All biodegradable retinal tacks reduce in size with time, but no retinal tacks extruded from the inserted place. The newly designed biodegradable retinal tack can be used for retinal fixation and may be used as a vehicle for the introduction of pharmacologic agents to prevent the cellular events that promote proliferative vitreoretinopathy.

위암환자의 복강내에 투여한 Mitomycin C-Carbon Particle의 Mitomycin 용출에 관한 연구

노승무,조영훈,정경수,오정연,김진향,양준묵,강대영,송규상,조준식,최선웅,이진호,민병무,김용백,김창식,박근성,인현빈,정현용,김학용 충남대학교 의과대학 지역사회의학연구소 1998 충남의대잡지 Vol.25 No.1

Locoregional recurrence is the most common type of recurrence in surgical operation of gastric adenocarcinoma, and peritoneal dissemination is one of the most difficult problems in advanced gastric adenocarcinoma treatment. Because the peritoneal cavity is the most common site of the first recurrence after gastric cancer resection, intraperitoneal chemotherpy seems a logical choice for cancer chemotherapy. The Mitomycin C(MMC) adsorbed by the activated charcoal particles(CH) is relatively released when the drug concentration surrounding the carbon particles becomes low in the peritoneum of the peritoneal cavity. For the intraperitoneal chemotherapy on the advanced gastric adenocarcnoma, mitomycin C adsorbed on activated carbon particles was administered in the peritoneal cavity just before abdominal wall closure. The closed drainage tubes were inserted in the peritoneal cavity and clamped for tuo hours after completion of operation. MMC concentrations were serially measured in peritoneal fluid, plasma and urine at 2hour, 48 hour, 72 hour and 168 hour following its administration in order to study the efficacy of the MMC-CH as a drug delivery system. There were minimal toxicities in born marrow, liver, and gastrointestinal system after intraperitoneal MMC-CH administration. The data of this study suggested that MMC-CH may have a somewhat more beneficial effect than surgery alone when administered in optimal dose and schedules, but the MMC concentration of the peritoneal fluid was not sufficient to eradicate remnant cancer cells, and effective duration of maintenance was only below 24 hours in the peritoneal fluid and plasma.

Bacillus 속 분리주가 생산하는 박테리오신의 특성 조사

함승희(Seung-Hee Ham),최낙식(Nack-Shick Choi),문자영(Ja-Young Moon),백선화(Sun-Hwa Baek),이송민(Song-Min Lee),강대욱(Dae-Ook Kang) 한국생명과학회 2017 생명과학회지 Vol.27 No.2

토하젓에서 분리한 박테리오신 생산 균주 중 상대적으로 넓은 항균스펙트럼을 나타내는 1균주를 선발하였고 16S rRNA 유전자 염기서열 분석 결과 B. subtilis E9-1와 거의 일치하는 것으로 동정되었다. B. subtilis E9-1가 생산하는 박테리오신의 물리화학적 특성을 조사하였고, 박테리오신을 정제하였다. 이 박테리오신은 B. cereus KCCM 11204, M. luteus IAM 1056, L. monocytogenes KCCM 40307, E. faecium KCCM 12118 및 S. aureus subsp. aureus KCCM 40050 등에 대해서 항균활성을 나타내었다. pH 2.0~8.0 범위에서는 안정하였으나 8.0 이상에서는 항균활성이 감소하였다. Isopropanol, ethanol 및 methanol 등의 유기용매에서 100%까지, acetone과 acetonitrile에서는 80%까지 항균활성을 유지하였다. 내열성의 경우 40~100℃에서 60분까지는 안정하게 항균활성을 보였다. 박테리오신 농도를 증가시키면서 B. cereus, L. monocytogenes, E. faecium 및 S. aureus subsp. aureus 등 시험균 4주의 감수성을 조사한 결과 농도 의존적으로 시험균의 생육이 감소하였고 이중 L. monocytogenes 의 감수성이 가장 높게 나타났다. 박테리오신의 작용양상을 알아본 결과 B. cereus와 L. monocytogenes 배양액에 박테리오신 용액을 첨가한 후 흡광도와 CFU값이 감소하여 bactericidal임을 확인하였다. 식품에 적용 가능성을 알아보기 위해 실험한 결과 3일째부터 박테리오신을 처리하지 않은 대조구에 비해 실험구에서 생균수(CFU/ml)가 감소하였다. 아세톤을 이용한 배양상등액의 농축, superdex peptide HR 10/300 column 이용한 겔여과크로마토그래피, 역상 HPLC로써 박테리오신을 정제하였다. 역상 HPLC를 통해서 정제한 박테리오신의 분자량을 tricine SDS- PAGE로 분석한 결과 약 4 kDa이었고 질량분석법으로 측정한 정확한 분자량은 3347.6 Da로 나타났다. As an effort to find a potential biopreservative, we isolated bacterial strains producing bacteriocin from fermented foods. A strain was finally selected and characteristics of the bacteriocin were investigated. The selected strain was identified as Bacillus subtilis E9-1 based on the 16S rRNA gene analysis. The culture supernatant of B. subtilis E9-1 showed antimicrobial activity against Gram-positive bacteria. Subtilisin A, α-chymotrypsin, trypsin and proteinase K inactivated the antimicrobial activity, which means its proteinaceous nature, a bacteriocin. The bacteriocin activity was fully retained at the pH range from 2.0 to 8.0 and stable at up to 100℃ for 60 min. Solvents such as ethanol, isopropanol and methanol had no effect on the antimicrobial activity at the concentration of 100% but acetone and acetonitrile reduced the activity at up to 100% concentration. Cell growth of four indicator strains was dramatically decreased in dose-dependent manner. Listeria monocytogenes was the most sensitive, but Enterococcus faecium was the most resistant. Bacillus cereus and Staphylococcus aureus showed the medium sensitivity. The bacteriocin showed its antimicrobial activity against B. cereus and L. monocytogenes via bactericidal action. The number of viable cells of L. monocytogenes started to reduce after addition of bacteriocin to the minced beef. The bacteriocin was purified through acetone concentration, gel filtration chromatography and RP-HPLC. The whole purification step led to a 6.82 fold increase in the specific activity and 6% yield of bacteriocin activity. The molecular weight of the purified bacteriocin was determined to be 3.3 kDa by MALDI-TOF/TOF mass spectrometry.

마이크로 핀을 이용한 니티놀 형상기억 합금의 마이크로 전해가공 특성 분석

신민정,백승엽,김백겸,이은상 한국공작기계학회 2007 한국공작기계학회 추계학술대회논문집 Vol.2007 No.-

Electrochemical micro machining, the anodic dissolution process without contact with tools, can achieve a wanted shape of the surface using electrochemical reaction between anode and cathode. Nitinol is a metal alloy composed of Ni and Ti around 50% respectively which has shape memory effect. Nitinol can be put various applications which require micro scale structure. The aim of this study is to investigate the characteristic of electrochemical micro machining for nitinol workpieces. In order to analyze the characteristics of electrochemical micro machining for nitinol, tungsten carbide micro pin was used for electrode and the machined area was observed by optical microscope.