Improvement of Thermoplastic Forming Ability of Ti–Zr–Ni–Cu Metallic Glass by Addition of Sn

Yeong‑Seong Kim,Woo‑Chul Kim,Won‑Tae Kim,Do‑Hyang Kim 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.6

Ti–Zr–Ni–Cu metallic glass attracts an attention as a precursor of superelastic alloy that can be deformed into nm scalecomplex shapes. However, since the thermal stability of Ti–Zr–Ni–Cu metallic glass in the supercooled liquid region is quitelow, application of thermoplastic forming is limited. Therefore, in the present study, the effect of Sn addition on thermoplasticforming ability of Ti–Zr–Ni–Cu metallic glass has been investigated. Sn containing (Ti35Zr15Ni35Cu15)99Sn1 metallic glassexhibits longer incubation time before onset of crystallization than Ti35Zr15Ni35Cu15metallic glass, resulting in significantimprovement of thermoplastic forming ability. The crystallization behavior changes from three-dimensional growth of saturatednuclei to three-dimensional growth with constant nucleation rate with the addition of Sn. The overall activation energyfor crystallization of (Ti35Zr15Ni35Cu15)99Sn1 metallic glass is higher than that of Ti35Zr15Ni35Cu15metallic glass, indicatingthat the thermal stability of metallic glass is improved by addition of Sn. Because nuclei are continuously generated duringthe crystallization in (Ti35Zr15Ni35Cu15)99Sn1, the average grain size is much smaller than that in Ti35Zr15Ni35Cu15.

Rifampicin에 의한 것으로 추정되는 위막성 대장염1예

김수현,이은우,정종혁,문승현,김동한,양혁승,오영상,김호동,김도현,박혁,박정환,박경옥,이영직 朝鮮大學校 附設 醫學硏究所 2006 The Medical Journal of Chosun University Vol.31 No.2

Pseudomembranous colitis, caused by altering the normal colonic flora and allowing the multiplication of Clostridium difficile, is an deleterious adverse effect of antibiotics. But it is rarely reported by rifampicin. Rifampicin is one of the first line drug in the treatment of tuberculosis and many patients are exposed to its potential adverse effects. We experienced a patient that had abdominal discomfort and hematochezia due to pseudomembranous colitis after receiving antituberculous medication, and which was probably caused by rifampicin. A 82 years old man was admitted with abdominal discomfort and hematochezia for one week. On the past history he had been diagnosed as endobronchial tuberculosis about 4 months ago. Colonoscopy revealed multiple discrete whitish mucosal lesion on rectosigmoid colon, and histologic findings were consistent with pseudomembranous colitis. The antituberculous agents were discontinued and vancomycin was administered. The patient's symptoms were resolved within several days. There was no recurrence after reinstitution of the antituberculous agents excluding rifampicin. We report here on a case of pseudomembranous colitis probably due to rifampicin.

Metagenomic Analysis of Fungal Communities Inhabiting the Fairy Ring Zone of Tricholoma matsutake

( Miae Kim1 ),( Hyeok Jun Yoon ),( Young Hyun You ),( Ye Eun Kim ),( Ju Ri Woo ),( Yeong Gyo Seo ),( Gyeong Min Lee ),( Young Ja Kim ),( Won Sik Kong ),( Jong Guk Kim ) 한국미생물 · 생명공학회 2013 Journal of microbiology and biotechnology Vol.23 No.10

Tricholoma matsutake, an ectomycorrhiza that has mutual relationships with the rootlet of Pinus denisflora, forms a fruiting body that serves as a valuable food in Asia. However, the artificial culture of this fungus has not been successful. Soil fungi, including T. matsutake, coexist with many other microorganisms and plants; therefore, complex microbial communities have an influence on the fruiting body formation of T. matsutake. Here, we report on the structures of fungal communities associated with the fairy ring of T. matsutake through the pyrosequencing method. Soil samples were collected inside the fairy ring zone, in the fairy ring zone, and outside the fairy ring zone. A total of 37,125 sequencing reads were obtained and 728 to 1,962 operational taxonomic units (OTUs) were observed in the sampling zones. The fairy ring zone had the lowest OTUs and the lowest fungal diversity of all sampling zones. The number of OTUs and fungal taxa inside and outside the fairy ring zone was, respectively, about 2 times and 1.5 times higher than the fairy ring. Taxonomic analysis showed that each sampling zone has different fungal communities. In particular, out of 209 genera total, 6 genera in the fairy ring zone, such as Hemimycena, were uniquely present and 31 genera, such as Mycena, Boletopsis, and Repetophragma, were specifically absent. The results of metagenomic analysis based on the pyrosequencing indicate a decrease of fungal communities in the fairy ring zone and changes of fungal communities depending on the fairy ring growth of T. matsutake.

8년간(1992~1999) 산업안전보건연구원에 의뢰된 직업병 심의 사례 분석

강성규,김규상,김양호,최정근,안연순,진영우,최병순,양정선,김은아,채창호,최용휴,김대성,박정선,정호근 대한산업의학회 2000 대한직업환경의학회지 Vol.12 No.2

Objectives : Pneumoconisis and noise-induced hearing loss (NIHL) have been reported as main occupational diseases by the Special Health Examination. The Industrial Accident Compensation Insurance has reported various work-related diseases, however, these two diseases occupied almost a half of compensated cases. Therefore, it was not well known about the status of occupational diseases other than pneumoconiosis, NIHL, and cardio-cerebrovascular accident (CVA). This study was conducted to analyze claimed cases as an occupational disease, that was requested to the Korea Industrial Safety and Health Agency (KOSHA). Methods : The local office of the Korea Labor Welfare Corporation (KLWC) has asked the KOSHA for confirmation of claimed cases as an occupational disease. We analyzed 379 cases requested from KLWC, the Ministry of Labor, employers, unions and occupational health agencies from 1992 to 1999. Results : Male was 80.7 % of the requested cases. Their mean age was 42 years old and 75.5 % of them were more than 35 years old. The requested cases were increased rapidly from 25 cases in 1992 to 108 cases in 1999 and the accept rate was 50.7 %. The majority of requested cases were respiratory diseases(22.4%), cancers(18.5%), Neuropsychiatric problems(14.5%), and musculoskeletal problems(13.5%). The accept rate was high in reproductive, respiratory, musculoskeletal and digestive disorders and low in neuropsychiatric, renal and otologic problems and occupational cancers. 73.6% of them were caused by chemical agents, especially 28.5 % were by organic solvents. 67% of them were clinically confirmed at university hospitals. A half of the cases were from KyongIn area, even the request came from the whole country. Conclusions : A claim was common in workers whose age was over 35 years old and exposure history was over 10 years. The respiratory diseases and neuropsychiatric disorders were still main problems in occupational health and occupational cancers was increasing even though its accept rate was not high yet.

구순구개열환자에서 자기늑골을 이용한 일차성 골이식

김종렬,정기돈,진성준,조영철,변준호,손우성 대한악안면성형재건외과학회 2000 Maxillofacial Plastic Reconstructive Surgery Vol.22 No.5

Alveolar bone grafting is an essential component of successful surgical rehabilitation in many common cleft deformities. Primary alveolar bone grafting is defined as alveolar bone grafting which takes place before eruption of the primary dentition or before 1 years of age. The major objective in primary alveolar bone grafting is to prevent significant maxillary segmental collapse and arch disturbances. If severe, this can make secondary rehabilitation difficult, costly, and protracted. Such early stabilization may eliminate or, at least, decrease the amount of orthodontic arch expansion required during the transitional dentition period. Furthermore, early obliteration of alveolus fistulae improves speech and dental hygiene. It is critical that abutting maxillary segmental alignment be achieved(generally when the patient is 8 to 10 months of age) before grafting. Otherwise, the amount of dissection necessary to develop mucosal flaps for bone graft coverage will be more extensive, thus risking increased scar formation with potential adverse effects on growth. We report a preliminary result of 4 cases of primary alveolar bone graft using rib bone, performed by limited dissection and onlay graft technique at 8 to 10 months of age. They showed satisfactory clinical results especially in terms of growth up to now.

수면무호흡증의 다원수면기록 소견

김용조,이선우,왕성근 대한생물치료정신의학회 1996 생물치료정신의학 Vol.2 No.2

To identify the clinical characteristics of sleep apnea syndrome in Korean, author analyzed 24 cases of polysomnographic findings statistically, diagnosed as sleep apnea syndrome during May, 1995 to July,1996. The results were summarized as follows: 1. The mean age of subjects was 35.7 years, the distribution of age was 12 to 64 years, and male to female sex ratio was 5:1. 2. As for mean values of sleep parameters, total bed time was 429.8 minutes, waking after sleep onset was 93.4 minutes, total sleep time was 336.1 minutes and sleep efficiency was 77.7%. 3. The proportions of sleep stage 1, stage2,slow wave sleep, REM sleep, and movement time to total sleep time were 13.1%, 39.4%, 24.4%, 20.8%, and 2.2% respectively. 4. Mean AI(apnea index) was 28.7 and RD(respiration disturbance index ) was 34.3. 5. Waking after sleep onset correlated with total sleep time and sleep efficiency negatively, and with sleep stage 1 positively. Sleep efficiency correlated with sleep stage 1 negatively, and sleep stage 1 correlated with slow wave sleep negatively.

飼料作物 Alfalfa(Medicago sativa L.)品種別 生育狀에 대하여

김무성,노영덕,김세영,백남인,정우진 경희대학교 부설 식량자원개발연구소 1996 硏究論文集 Vol.17 No.-

서로 특성이 다양한 32개의 도입한 Alfalfa품종을 우리나라 중부지역인 충청남도에 재배하여 초장과 건물중 등의 생육상태를 비교, 검토한 결과는 다음과 같다. 1. 평균초장이 큰 상위 10개 품종들은 Dekalb brand 135 > Diamond > Pioneer brand 581 > Raidor > Pioneer brand532 > Pierce> Nitro > Sparta ) Florida 77 > Sapphire의 품종순 이 며, 초장이 작은 10개 품종을 최하위 순으로 열거하여 보면 Salute < Spredor 2 < LS-1920 < Arrow < Challenger < Milkmaker < Armor < Pioneer brand 545 < Pioneer brand 5262 < Saranac의 품종 순이였다. 2. 총건물 수량이 많은 상위 10개 품종들은 Diamond > Nitro > Dekalb brand 120 > Dekalb brand 135 > Drummer > Saranac > Sapphire > Raider > Magnum > Dekalb brand 167의 품종 순이며, 건물수량이 적은 최하위 순으로 10개 품종은 Milkmaker < Pioneer brand 526 < Pioneer brand 5262 < Salute < Pioneer brand 555 < Decathlon < Pioneer brand 5929 < LS-1920 < Pioneer brand 581 < Husky의 품종들이였다. 3 평균초장과 총건물 수량의 결과를 비교하여 보면 대체로 초장이 우세하였거나, 열세하였던 품 종들이 다소간 건물수량이 우세하거나 열세하였으며, 정비례한 결과는 보이지 아니하였다. 4. 생육상태 및 건물수량이 모두 좋은 품종들은 Diamond, Nitro, Dekalb brand 135, Sapphire, Raidor품종들이며, 우리나라 중서부지역의 재배환경에 적합한 품종으로 사료된다 This study was conducted to select the best adapted alfalfa cultivars among the 32 introduced alfalfa cultivars with different characteristics in Chung-Chong Nam Do, Korea, environmental condition. Mean of plant height and total dry matter yields per cultivar from May to August in 1996 were determined. On the point of mean of plant height, ten high ranked cultivars among the 32 alfalfa cultivars in high order were Dekalb brand 135>Diamond>Pioneer brand 581>Raidor>Pioneer brand 532>Pierce>Nitro>Sparta>Florida 77>Sapphire and ten low ranked cultivars in low order were Salute<Spredor 2<LS-1920<Arrow<Challenger<Milkmaker<Armor<Pioneer brand 545<Pioneer brand 5262<Saranac. Ten high ranked cultivars from 32 alfalfa cultivars on the total dry matter yields in high order were Diamond>Nitro>Dekalb brand 120>Dekalb brand 135>Drummor>Saranac>Sapphire>Raidor>Magnum>Dekalb brand 167 and ten low ranked cultivars in low order were Milkmaker<Pioneer brand 526<Pioneer brand 5262<Salute<Pioneer brand 555<Decathlon<Pioneer brand 5929<LS-1920<Pioneer brand 581<Husky. Total dry matter yields of per cultivar was also slightly greater but It was not appeared direct proportion when alfalfa cultivar was appeared higher mean of plant height compared with those which were lower mean of plant height. Leading alfalfa cultivars for plant growth and dry matter yields were Diamond, Nitro, Dekalb brand 135, Sapphire, Raidor cultivar which can be well grown under moderate temperatures zone of midwest in Korea.

이미지 개선 및 선 정보를 이용한 자동차 번호판 추출

김기영,최영우 숙명여자대학교 자연과학연구소 2000 자연과학논문집 Vol.- No.11

본 논문은 실외 도로에서 획득한 낮은 질의 차량 영상에서 이미지를 개선하고 선 정보를 이용하여 자동차 번호판을 추출하는 방법을 제안한다. 이미지의 질을 개선하기 위해서 명암 대비를 이용한 스트레칭 방법과 수정된 Niblack의 이진화 방법을 사용하여 전처리를 수행한다. 선 정보추출은 기존에 많이 사용된 허프 변환이 시간과 메모리 소모의 단점이 있으므로, 이진화한 영상에서 에지를 추출하여 만든 런(Run)의 연결 요소를 분석하여 선으로 병합하는 방법을 제안한다. 추출된 선 가운데 수직선을 기준으로 후보 영역을 결정하며, 번호판 영역의 명암 변화도 값, 명암 변화도 패턴 및 구조적인 정보를 이용하여 검증한다. 제안한 방법을 적용한 결과 불규칙한 조명이나 노면 상태 등에서 획득한 낮은 질의 이미지에 대해서도 50%이상의 번호판 추출률을 보였다. This paper propose a method fur extracting license plate areas from low quality vehicle images using image enhancement and line information. To improve the quality of the images we apply an improved histogram stretching method and a modified Niblack's binariBation method to the images in the preprocessing stage. And the lines are extracted from the image by combining multiple runs of horizontal and vertical edges instead of using computation intensive Hough transforms. Candidate areas of the licence plate are assumed by combining pairs of the vortical lines first and then by composing rectangular areas in the image. The candidate areas are verified by analyzing gray level variations and their patterns with plate's structural information. We have applied the proposed method to the various kinds of the low quality vehicle images and obtained the extraction rate of more than 50%.

절삭력 최적화를 위한 이송속도 제어 시스템에 관한 연구

김성진,정영훈,조동우 한국공작기계학회 2002 한국공작기계학회 추계학술대회논문집 Vol.2002 No.-

Studies on the optimization of machining process can be divided into two different approaches: off-line feedrate scheduling and adaptive control. Each approach possesses its respective strong and weak points compared to each other. That is, each system can be complementary to the other. In this regard, a combined system, which is a feedrate control system for cutting force optimization, was proposed in this paper to make the best of each approach. Experimental results show that the proposed system could overcome the weak points of two systems.

소각 비산재의 적정처리를 위한 기초연구(Ⅱ) : 용출인자의 영향;Effect of Leaching Parameter

김진범,이우근,심영주 江原大學校 附設 環境硏究所 2000 環境硏究 Vol.17 No.-

본 연구는 소각 비산재의 물리·화학적 특성이 중금속의 용출 거동에 미치는 영향을 알아보고자 수행하였다. 영향인자로는 비산재의 pH, CEC, 입자크기, 연속추출방법에 의해 분류된 중금속의 존재형태 중에서 exchangeable fraction을 고려하였다. KSLT법에 의한 중금속의 용출율은 pH에 크게 의존적이고 원소에 따라 차이를 보였다. 카드뮴과 구리의 용출율은 pH가 증가함에 따라 감소한 반면, 납과 아연은 중성 또는 강알칼리성 조건에서 증가하는 것으로 나타났는데 중금속의 용출 거동이 용해도에 의해 제한됨을 나타내 준다. CEC가 중금속의 용출율에 미치는 영향은 pH와 비슷한 것으로 나타났다. 비산재의 입자크기 중에서 D_(10)은 KSLT법에 의한 중금속의 용출량과 음의 상관성을 나타내었다. Exchangeable fraction의 경우는 비산재의 CEC 값이 40 meq/100g 미만인 시료는 선형관계에 있지만, 그 외의 CEC 값에서는 비선형관계를 보여주었다. Our study was performed to evaluate the effect of leaching parameters including the physicochemical characteristics and the fractionated composition of heavy metals on the release of heavy metals in fly ash discharged from MSWI. Leaching parameters such as pH, CEC, particle size, and exchangeable fraction among the fractional composition classified by sequential extraction procedure are considered. The leaching rate of heavy metal released by KSLT method is largely dependent on the pH of fly ash. The effect of pH on the release of heavy metals is different from elements. It appears that the leaching rate of cadmium and copper decreases with increasing pH, While lead and zinc increases at the condition of neutral or strong alkali condition, which suggests that the leaching of heavy metals are limited by the solubility. It is found that the effect of CEC is similarly to that of pH. D_(10) among the particle size of fly ash is negative correlated with the concentration of heavy metals leached by KSLT method. In the case of exchangeable fraction, the leaching rate of heavy metals is linearly correlated with the exchangeable fraction for the fly ash below 40 meq/100g of CEC, but not related out of the range.