• 한국버섯학회지
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• 제18권4호
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• pp.393-397
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• 2020

Mycelium composites and leathers have versatile material properties based on their composition and manufacturing process. To prepare mycelium mat for the production of mushroom leather, several strains were mutated by gamma rays. Some mutant strains, including Lentinula edodes, Ganoderma lucidium, and Schizophyllum commune showed good hyphae growth rate and density on saw-dust media. Irradiation power (Gy), time, and height from the radiation source to the sample were examined. Based on the preliminary data obtained in this study, comprehensive research should be conducted to explore the optimal strains and culture conditions for mycelium-based leather production.

• 한국기계가공학회지
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• 제21권1호
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• pp.28-33
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• 2022

The heating roller of an actual pulse output device (POD) production facility is composed of a steel roller and a rubber roller. The time to reach a specific temperature and the temperature distribution on the roller surface were analyzed and compared according to the change in the number of cartridge heaters inside the heating roller. In this analysis, a steady-state thermal analysis of a steel roller was performed for the cases of a 5-cartridge heater and 9-cartridge heater. Finite element analysis was applied with reference to the surface temperature data of the heating roller during operation and the calorific value of the cartridge heater. Using the 9-cartridge heater, faster target temperature achievement and more uniform temperature distribution were confirmed than for the 5-cartridge heater.

• Design & Manufacturing
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• 제16권2호
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• pp.13-19
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• 2022

Recently, electric vehicles are gaining popularity among many domestic and foreign users due to their eco-friendly advantages of reducing fine dust and environmental greenhouse gases. As the demand and supply of electric vehicles increase, the demand for electric vehicle charging infrastructure is also growing together. Many users are experiencing inconvenience due to poor charging infrastructure, which makes them hesitant to buy electric vehicles. Research on the user experience of chargers in apartment complexes, a common residential type in Korea, is being conducted somewhat, but research on the design of electric vehicle charging devices in public places is insufficient. The purpose of this research is to identify user requirements and complaints based on the product design of the electric vehicle charger in public places and propose a new electric vehicle product design concept that meets the requirements. The research method understood the charging base and status of electric vehicles in public places through literature research and examined and analyzed the characteristics and problems of product design cases that improved the charging problem of electric vehicles recently released in the market. It is intended to identify and analyze the problems of the charging device product design through user interviews, a qualitative research method, and based on this, it is intended to propose a user-centered product design concept that improves major complaints.

• 월간산업보건
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• 통권8호
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• pp.4-30
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• 1988

Examination of working environments was conducted to get more detailed data about harmful working environments and to make a contribution to more effective management. Study was carried out on 722 factories located in Taegu city and eight counties in Kyungpook Province, Korea, for a period of one year, from February 1 to December 30, 1986. The total number and proportion of workers exposed to harmful material was 37,697, 45.2% among 83,368 workers. The results according to exposed material were as follows: 1. In the case of noise, proportion of exceeding the 8-hour TLV was 59%, Included were nail-cutting in assembly metal manufacturing industry and weaving process in textile. 2. Dust in mill process of coal manufacturing industries exceeded the TLV of second class of dust at all parts and exceeded the TLV at 6% as a whole.: 3. The fields of industry lower than 70 lux of illumination were storage equipment of food, auto-winder of textile, painting of wood wares and coal mixing, and 44% of all cases was lower than standard. 4. As a result of temperature index investigation(WBGT), about 12% of all sujects exceeded limit value. Included parts were rolling machine and reducing room. 5. In the case of organic solvents, TLV was exceeded at about 8%, The parts exceeded TLV according to materials belonged to this category were as follows. 1) Toluene: adhesive work in assembly metal manufacturing 2) Xylene: printing and paint mixing in chemical manufacturing 3) Methyl ethytl ketone: paint mixing in all parts examined and coating machine partially in chemical manufacturing 4) Methyl isobutyl ketone: printing in chemical manufacturing 5) Acetone: vapor polishing in assembly metal manufacturing 6. Among specified chemical materials, the concentration of HC1 in the air in metal assembly manufacturing factory exceeded TLV. in one of three assembly metal manufacturing examined. Others, such as benzene, acetic acid, formic acid, sodium hydroxide, formalin, ammonia, copper, chromate etc. were lower than TLV in its indoor atmospheric concentration. As a whole, the proportion of exceeding TLV was about 0.8% 7. The concentrations of inorganic lead were lower than TLV in all parts examined. The results of this investigation show the fact that current management of working environments is not satisfactory, and so more active management is needed.

• 한국산업보건학회지
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• 제24권4호
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• pp.547-555
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• 2014

Objective: This study was conducted to investigate the association between subjective distress symptoms and argon welding among workers in Gyeongnam Province shipyard. Method: 31 argon and 29 non-argon welding workers were selected as study subjects in order to measure concentrations of personal dust, welding fumes and other hazardous materials such as ZnO, Pb, Cr, FeO, MnO, Cu, Ni, $TiO_2$, MgO, NO, $NO_2$, $O_3$, $O_2$, $CO_2$, CO and Ar. An interviewer-administered questionnaire survey was also performed on the same subjects. The items queried were as follows: age, height, weight, working duration, welding time, welding rod amounts used, drinking, smoking, and rate of subjective distress symptoms including headache and other symptoms such as fever, vomiting and nausea, metal fume fever, dizziness, tingling sensations, difficulty in breathing, memory loss, sleep disorders, emotional disturbance, hearing loss, hand tremors, visual impairment, neural abnormality, allergic reaction, runny nose and stuffiness, rhinitis, and suffocation. Statistical analysis was performed using SPSS software, version 18. Data are expressed as the mean ${\pm}SD$. An ${\chi}^2$-test and a normality test using a Shapiro wilk test were performed for the above variables. Logistic regression analysis was also conducted to identify the factors that affect the total score for subjective distress symptoms. Result: An association was shown between welding type (argon or non-argon welding) and the total score for subjective distress symptoms. Among the rate of complaining of subjective distress symptoms, vomiting and nausea, difficulty breathing, and allergic reactions were all significantly higher in the argon welding group. Only the concentration of dust and welding fumes was shown to be distributed normally after natural log transformation. According to logistic regression analysis, the correlations of working duration and welding type (argon or non-argon) between the total score of subjective distress symptoms were found to be statistically significant (p=0.041, p=0.049, respectively). Conclusion: Our results suggest that argon welding could cause subjective distress symptoms in shipyard workers.

• 대한임상검사과학회지
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• 제49권4호
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• pp.435-438
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• 2017

비결핵 항상균(Nontuberculous Mycobacteria, NTM) M. avium-intracellular complex (MAC), M. fortuitum, M. chelonae, M. abscessus, M. kansasii 등을 함유한다. 비결핵 항상균은 자연 환경속에 서식하며 다양한 가축등에 감염한다. 그리고 사람한테는 기회감염을 유발하여 사회적 경제적 문제를 야기한다. 본 연구는 면역결핍 사람한테 기회감염을 유발하는 비결핵 항상균이 사람들이 흔히 이용하는 다중이용시설내 존재 유무를 확인하기위해 40개 에어컨 먼지를 채취하여 직접 AFB 염색, 직접 PCR, 간접 AFB 염색, 간접 PCR 등을 실시했다. 그 결과 채취한 샘플의 직접 AFB 염색, 직접 PCR 에서는 인형결핵균(MTB), 비결핵 항상균 모두 발견되지 않았다. 배양된 집락을 이용한 간접 AFB 염색, 간접 PCR 결과 인형결핵균 (MTB)은 모두 음성반응을 나타냈으며, 비결핵 항상균은 40개 샘풀 중 2개(5%)에서 양성반응을 나타냈다. 본 실험결과는 자연 내 비결핵 항상균이 존재한다는 사실을 증명했으며 비결핵 항상균이 기회감염의 원인임을 감안했을 때 다중이용시설의 청결한 위생처리가 중요함을 암시한다. 다만 비결핵 항상균의 종(species) 감별과 기회감염 유발 유무는 좀 더 연구가 필요하다고 사료된다.

• 대한화학회지
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• 제62권5호
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• pp.358-363
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• 2018

화석연료의 사용과 그 2차오염으로 인해 매년 수도권의 초미세먼지(PM2.5)는 점점 증가하는 추세에 있다. 본 연구는 초미세먼지의 주된 원인물질이라고 알려져 있는 자동차의 매연에서 발생하는 $NO_x$의 제거에 저렴한 Cu 촉매의 이용 가능성에 초점을 두었다. 이를 위하여 일산화질소(NO) 분자가 Cu에 결합하여 형성할 수 있는 Cu-NO 복합체의 가능한 3가지 구조에서의 에너지와 결합길이, IR 및 라만 스펙트럼의 변화를 알아보기 위하여 Gaussian 09 프로그램에서 MPW1PW91 법을 이용하여 기저함수 6-311(+)G(d,p) 수준에서 계산을 수행하였다. 그 결과, Cu-NO 복합체의 생성 엔탈피는 선형, 굽은형, 다리형 구조에 대하여 각각 ${\Delta}H=104.89$, 91.98, -127.48 kJ/mol의 값을 얻었고, NO 결합길이는 복합체가 되었을 때 약 $0.03{\sim}0.10{\AA}$ 정도 NO 분자보다 길어지는 경향을 보여 Cu-NO 결합으로부터 O가 보다 쉽게 환원될 수 있음을 보여준다. 또한 NO와 Cu-NO 복합체의 IR 및 라만 스펙트럼은 각 진동 모드에 대한 피크의 위치와 세기가 확연히 달라져 Cu 촉매에서 Cu-NO 복합체의 생성 여부도 적외선 또는 라만 분광법으로 손쉽게 확인될 수 있음을 알 수 있었다.

• 천문학회보
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• 제36권1호
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• pp.42.1-42.1
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• 2011

The main payload of the Science and Technology Satellite 3 (STSAT-3), Multipurpose Infrared Imaging System (MIRIS), will be equipped with the wide-field near-infrared camera. Its wide field-of-view ($3.67^{\circ}{\times}3.67^{\circ}$) is optimal for the observation of the zodiacal light (ZL), the sunlight scattered by the interplanetary dust (IPD). The MIRIS will continuously monitor the seasonal variation of the ZL towards both north and south ecliptic poles, which is caused by the asymmetries of the IPD distribution with respect to the Sun and the ecliptic plane. In addition to the monitoring observations, we are planning pointed observations for compelling structures in the ZL, the asteroidal dust bands and the gegenschein. This presentation proposes the zodiacal light observations with the MIRIS and discusses the expected results.

• 한국산업보건학회지
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• 제6권2호
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• pp.281-291
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• 1996

458 female workers working in the small and medium scaled industries in Inchon area were surveyed to study their general characteristics, health behavior, working and environmental conditions, awareness of exposure at hazardous materials, current health status, and degree of working satisfaction. Self-administered questionnaire was distributed to the female workers with the explanation by trained interviewer on the purpose of survey and the method how to answer. The results were as follows : (1) 75.5% of the respondents are living with their families and others are living in domitary or rent house for herself. Age distribution ranges from teenagers to warren in their forties. In marital status 69.0% of workers are single and 31.0% of them have ever married. 69.4% of workers are high school graduate. The size of factory is 48.3% with less than 300 workers, 42.1% with 300~500 workers. (2) Most of the workers(86.7%) are full time workers, 52% of the respondents have working experiences in other factories. More than 65% have fewer than 5 years working experience. (3) The awareness of exposure at noise was 33% of respondents, it was significantly different by skilled status. The awareness of exposure at dust, other hazardous material was each 13.3%, 12.4% of respondents. (4) 26% of them are unsatisfied with their working cognitions and 43.7% of them are unsatisfied with their welfare in occupational system unsatisfactory rate of promotion is higher in the unmarried workers(45.6%), skilled workers(47.2%), full time workers(47.4%), long term workers(50%), and awareness group of exposure hazardous material(51.3%), compared to married women workers, unskilled workers, part-time workers, short term workers and unawareness group of exposure at hazardous materials. (5) The index of working satisfaction is rated on a scale of 1 to 10 with the higher point indicating higher satisfaction. Among the selected variables, marital status, working status, the awareness of exposure at hazardous materials, were statistically significant with the index of working satisfaction. (6) By multiple regression analysis showed that the determinant factors of index of working condition were health index, the awareness of exposure at dust, the awareness of exposure other hazardous materials, marital status and working period. In conclusion, there is a significant relationship between the awareness of exposure at hazardous material the index of working satisfaction. Therefore if the workers are less exposed to the hazardous material and are educated properly they will be more satisfied with their work thus improving their health and productivity. Finally, with the result of this study, there is a great need for the development of a health promotion program and a welfare policy for small-scale factories.

• 한국축산시설환경학회지
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• 제13권3호
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• pp.195-200
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• 2007

무창 육성 비육돈사에 대한 악취 제어 효율 비교분석을 위하여 Biofilter 덕트에 의한 악취 제어 연구를 수행하였다. 본 실험은 서울대 부속목장 실험돈사에서 실시하였으며 실험결과는 다음과 같다. 1. 무창 육성비육돈사에서 여름철 최대 배기시 바이오필터 외부로 배출되는 공기속도는 볏짚(.0.77 m/s), ALC(0.56 m/s)으로 측정되었다. 2. 실험시작 5일 후 가스검지기(GV-100)에 의한 간이측정시 암모니아($NH_3$) 농도는 필터 통과 후 볏짚($2mg/{\ell}$), ALC(3ppm)로 측정되어 부자재 사이의 공극율이 높은 볏짚이 높게 나타났다. 부자재에 따른 필터외부에서의 먼지측정 결과 볏짚($93\;mg/m^3$), ALC($32\;mg/m^3$)으로 측정되어 볏짚은 볏짚 간의 넓은 공극에서 발생하는 먼지 및 돈사내부의 먼지가 혼합되어 필터 외부로 배출되어 돈사내부보다 높게 측정되었다. 3. 황화수소($H_{2}S$) 가스농도 변화는 돈사내부에서는 측정일 7일(6 ppm), 21일(5 ppm) 및 36일(7 ppm) 경과함에 따라 어느 일정 시점에서 황화수소 가스농도는 증가하지 않았으나 다른 필터여재에서는 일정한 경향은 보이지 않았다. 이상의 실험결과를 종합해 볼 때 무창 육성비육 돈사에서 Biofilter를 이용한 악취저감 효과를 확인할 수 있었다.