Improved Pneumoconiosis Prevention: Surfactant-Added Spray System for Respirable Coal Dust

김윤광,Timothy D. Kim,윤찬훈 한국자원공학회 2009 한국자원공학회지 Vol.46 No.3

An occupational disease caused by prolonged inhalation of coal dust, pneumoconiosis can further develop into a more dangerous malady, such as bronchial disease, emphysema of the lungs, or pulmonary tuberculosis. Poor atmospheric working conditions in unhealthy coal mines can worsen the condition. Most coal mines currently use a simple water spray system to minimize coal dust and improve working conditions. This study performs a feasibility test on a more effective spray system using surfactants. Korea Coal Corporation provided coal dust samples for a scaled spraying model test. Chemical composition, physical shape, and particle size distribution of the sample dust were taken into consideration. A standard sink test was performed with four different surfactants at six different concentrations. Using the optimal surfactant chosen from the sink test, the overall collection efficiency of coal dust with the surfactant-added spray system increased by 11.23%, compared to the efficiency of the pure water spray. Also, the collection efficiency of fine dust (0.4 ㎛~2.1 ㎛) increased by approximately 40%. Spray systems using this kind of surfactant are judged to be effective in controlling fine dust below the geometric diameter of 3.5 ㎛, which is the size of the dust causing pneumoconiosis.

화순광업소의 효율적 통기운용에 관한 연구

김윤광,김진 한국자원공학회 2007 한국자원공학회지 Vol.44 No.5

The working environment is deteriorated due to a rise in temperature of a coal mine caused by increase of its depth and carriage tunnels. To improve the environment, the ventilation evaluation on Hwa-soon coal mine is carried out and the effect of a ventilation shaft on the temperature to enhance the ventilation efficiency in the subsurface is numerically analyzed. Also, the temperature distribution resulted by using the fan type ventilation system aiming for the temperature drop is calculated by using a fluid dynamic analysis program. The analysis shows that Hwa-soon coal mine needs 4,340 m3/min for in-flow ventilation rate but the total input air flowrate is 3,822 m3/min, 518 m3/min of in-flow ventilation rate shortage. The 106 m hypothetical ventilation shaft from -238 M.L to -344 ML could result about 3℃ temperature drop in the coal mine of -441 ML. The temperature between the carriage tunnel openings and the workings with exhausting ventilation system type is 2~3℃ less than that with blowing ventilation system type. The exhausting ventilation system type would be more effective than blowing ventilation system when the distance between the carriage tunnel openings and the workings is relatively far. 채굴의 심부화 및 운행갱도의 증가로 인한 온도상승으로 작업환경이 점차 악화되는 광산에서 작업환경의 개선을 위하여 화순광업소를 대상으로 통기평가를 하였으며 갱내의 통기 효율을 증가시키기 위하여 통기수갱을 건설할 시에 온도에 대한 효과를 수치 해석하였다. 또한 작업장에서의 온도 저하를 위한 선풍기 통기 방식에 대해 유동해석 프로그램을 이용하여 통기방식에 따른 운반갱도의 온도분포를 해석하였다. 연구결과 화순광업소의 소요통기량은 4,340 m3/min으로 산출되었으며, 실제 총 입기량은 3,822 m3/min로 통기량이 518 m3/min 부족한 것으로 나타났다. -238 ML에서 -344 ML까지 106 m 길이의 통기수갱을 건설하였을 시에 -441 ML 막장의 온도가 현재보다 약 3℃가 감소되었다. 그리고 운반갱도에서 작업장까지의 온도는 송기식 통기보다 배기식 통기방식이 2~3℃ 낮게 분포하였다. 운반갱도에서 작업장까지의 길이가 긴 경우 송기식보다는 배기식 통기방식을 운용 하는 것이 더욱 효과적일 것이다.

중국유감

김윤광,Kim, Yun-Gwang 기술표준원 2004 기술표준 Vol.27 No.-

The effects of epidural versus intravenous patient-controlled analgesia on postoperative outcomes in elderly patients who have undergone gastrectomy: a retrospective trial

김윤광,이지희,강석희,최용준,이지연,이소영,이수남,이은주,이청 대한마취통증의학회 2017 Anesthesia and pain medicine Vol.12 No.4

Background: Efforts for improving surgical outcomes in elderly patients should include the prevention of perioperative complications and proper postoperative pain management. Epidural analgesia is effective in decreasing perioperative stress and postoperative complications, and in improving recovery. Recently, it has been suggested that epidural analgesia may attenuate immune suppression during the perioperative period and lead to reductions in cancer recurrence and improvements in overall survival. Assuming that these effects of epidural analgesia are present in vulnerable elderly patients, we compared the efficacy of epidural patient-controlled analgesia and intravenous patientcontrolled analgesia on postoperative outcomes in elderly patients who had undergone gastrectomy. Methods: We evaluated 214 elderly patients who had undergone elective open gastrectomy for gastric cancer from 2011 to 2014. The demographic characteristics, analgesic efficacy, complications within the first 30 postoperative days, hospital stay, 24-month postoperative morbidity, cancer recurrence, and mortality were studied retrospectively. Results: Two-hundred and five patients were analyzed. Eighty-five patients received epidural patient-controlled analgesia (EPCA group) and 120 patients received intravenous patient- controlled analgesia (IVPCA group). The maximum pain scores were decreased to a greater extent in the EPCA group on the day of the operation (P < 0.001) and on the first postoperative day (P = 0.001) when compared to the IVPCA group. The patients in the EPCA group also required less analgesics on the day of the operation (P = 0.033) than those in the IVPCA group. The effect of EPCA on complications within the first 30 postoperative days, 24-month postoperative morbidity, cancer recurrence, and mortality were negligible in our study. Conclusions: EPCA provided more effective pain control than IVPCA in elderly patients who had undergone elective gastric cancer surgery, but did not affect postoperative outcomes.

溺死證明에 必要한 珪藻의 硏究 : 第1編 漢江流域의 珪藻에 對하여 第2編 溺死場所推定에 對하여

金潤光,崔日薰 우석대학교 의과대학 1968 우석의대잡지 Vol.5 No.1

This study was to investigate the planctons that obtained mainly from the Han River valley in the four selected areas near Seoul city, three times a day (7, 12, 21 hrs.) during two-month period(July 15 th, 1966 to Sept. 15 th,) and that appeared in the organs of the drowned rats in the rainy and clear weather. The results obtained were as follows: 1. The obtained planctons from this study consists of twenty-one kinds including Synedra and Navicula. 2. The number of the planctons among the four areas was the largest in Dook-sum, and less in Haeng-ju, Kim-po and Pal-dang, in the order of decreasing amount. However, there were differences in the kinds of the plancton according to the different area. 3. To see in terms of the obtained hour differences, the number of the plancton was the most during the day time, however, no particular differences between the morning and the evening were seen. 4. Cymbella and Synedra tend to be appearing more during the day time, while Navicula in the evening. 5. Correlation of the amount of plancton and rain was observed; less plancton during more rainy days and vice versa. 6. Particular ones that decreased or disappeared during the rain were Stephanodiscus and Melosira. 7. The number and kinds of planctons in the lungs of drowned rats coincide with those in the water. 8. Synedra and Cyclotella among 21 kinds were found from the various organs of the all experimental rats in the four areas mentioned above.

한국기기유화시험연구원

김윤광 대한기계학회 2009 기계저널 Vol.49 No.12

溺死證明에 必要한 珪藻의 硏究

金潤光 우석대학교 의과대학 1968 우석의대잡지 Vol.5 No.1

유관기관컬럼-유럽 중소기업의 표준화 촉진시책과 시사점

김윤광 기술표준원 2007 기술표준 Vol.69 No.-

인공신경망을 이용한 심부 갱내온도 예측

김윤광(Yunkwang Kim),김진(Jin Kim) 한국암반공학회 2007 터널과지하공간 Vol.17 No.4

심부 탄광 개발의 타당성 검토나 통기계획 수립시 갱내 작업장의 온도를 예측하는 것은 매우 중요하다. 심부의 탄광주변의 암반은 매우 다양하고 여러 암종으로 구성되어 있어 암반의 열 전도율(thermal conductivity)를 구하는 일은 매우 어려운 작업이다. 이에 본 연구에서는 복잡한 갱내여건에 상응한 열전도율을 도출하기 위해 artificial neural network(인공신경망)를 새롭게 도입하여 갱내 기상 예측을 위한 전산 프로그램을 개발하였다. 인공 신경망을 이용한 열전도율 계산 프로그램은 back-propagation algorithm을 사용하였으며 9개의 인자를 받아들이는 input layer와 5개와 3개의 뉴런을 가지는 두 개의 hidden layer로 구성되어져 있다. 개발된 TemPredict를 이용하여 장성광업소의 심부온도를 검증한 결과 장성생산부 -300 ML 하반구 입구의 25.65℃온도가 로 산출되었고 실제 온도 (25.7℃)와 0.05℃의 차이를 나타냈다. 이는 오차 범위 5% 이내에 포함되는 것으로 검증결과 95% 이상의 높은 신뢰도를 나타냈다. 위의 검증결과를 통해 TemPredict를 이용하여 현재 굴진중인 -425 ML이 관통이 되었을때의 장성생산부 주운반갱도 9X지점의 온도를 예측하였다. 예측 결과 장성생산부 주운반갱도 9X지점의 온도는 28.2℃로 예측 되었다. 향후 TemPredict를 통한 온도예측을 통하여 광산이나 지하구조물의 설계시 통기계획에 많은 도움을 줄 것으로 기대된다. The prediction of temperature in the workings for the propriety examination for the development of a deep coal bed and the ventilation design is fairly important. It is quite demanding to obtain precise thermal conductivity of rock due to the variety and the complexity of the rock types contiguous to the coal bed. Therefore, to estimate the thermal conductivity corresponding to this geological situation and complex gallery conditions, a computing program, which is TemPredict, is developed in this study. It employs Artificial Neural Network and calculates the climatic conditions in galleries. This advanced neural network is based upon the Back-Propagation Algorithm and composed of the input layers that are acceptant of the physical and geological factors of the coal bed and the hidden layers each of which has the 5 and 3 neurons. To verify TemPredict, the calculated result is compared with the measured one at the entrance of -300 ML 9X of Jang-sung production department , Jang-sung Coal Mine. The difference between the results calculated by TemPredict (25.65℃) and measured (25.7℃) is only 0.05℃, which is less than the allowable error 5%. The result has more than 95% of very high reliability. The temperature prediction for the main carriage gallery 9X in -425 ML under construction when it is completed is made. Its result is 28.2℃. In the future, it would contribute to the ventilation design for the mine and the underground structures.

RP용 포토폴리머의 최적주조조건에 관한 연구

김우순,김윤광,김동현 한국공작기계학회 2006 한국공작기계학회 추계학술대회논문집 Vol.2006 No.-

Rapid prototyping technologies have been widely used to reduce the development cost of new products. Manufacturing industries are nowadays characterized by the flexibility and complexity of products. This to due to the rapid development of manufacturing technology and diverse needs of customers. In this paper, the best burning out and casting condition for getting casting product of resin pattern(photopolymer) have been examined experimentally. In generally, the burning out and casting conditions have effect on the casting products. Using the direct casting. we directly producted the jewelry. And in this paper, we used only gypsum. Many study of casting for resin have been used to dental investment. A dental investment is good for resin casting. but dental investment is too hard and not useful on the jewelry casting. Therefore we need to find the way of resin casting by gypsum.