공동주택 등에 설치하는 도시가스 압력조정기의 안전성 향상에 관한 연구

윤영만,권용재,김경호,장지현 한국가스학회 2023 한국가스학회지 Vol.27 No.2

본 연구는 공동주택에 도시가스를 공급하기 위해 정압기 대신 설치하는 공용 압력조정기의 안전성 향상을위한 대안을 마련하기 위한 목적으로 진행되었다. 먼저, 국내 압력조정기의 안전기준 및 설치 실태를 조사하여 문제점을 도출하고 해결방안을 제시하였다. 또한 정량적 위험성평가 솔루션인 DNV Phast-Safeti 프로그램을 이용해 공동주택에 설치되는 압력조정기와 주변 가스설비에 내포된 가스누출 등의 위험성을 개인적 위험도와 사회적 위험도로 구분하여 평가하고, 압력조정기의 설치와 관리 측면에서 위험성 감소를 위한 방안을도출하였다.

필러 배합에 따른 치면열구전색재의 법랑질 결합 및 강도특성

윤영만,이용근,이흥수 대한구강보건학회 2000 大韓口腔保健學會誌 Vol.24 No.1

One of the characteristics that can predict the cariostatic effect of dental pit and fissure sealants is wear resistance of the material, and those for the expectation of the retention rate is the bond strength to enamel. Although the Bis-GMA resin based sealants are widely used, their mechanical properties are lower than those of composite filling resins because of lower cross-linking of the material. After incorporation of filler to the resin sealant, almost all the mechanical properties are improved except tensile strength. Incorporation of filler also results in higher abrasion resistance, and easy discrimination of the sealant. However there are a few reports on the mechanical properties and bond strength of sealant after incorporation of various amount of filler to the same resin for sealant. The purpose of this study was to determine the bond characteristics to enamel and the biaxial fracture strength of dental pit and fissure sealants after incorporation of various amount of glass fillers to the same unfilled resin sealant. Light cured pit and fissure sealants(CO and TM) were used as controls. Glass filler was incorporated in the chemically cures resin sealant(HP) with the ratio of 10, 30 and 50 wt.%, and was used as experimental groups, Two types of fillers, silane-coated and not coated, were used. For bonding test, flat enamel surface was made on sound premolar tooth by grinding with #600 silicone carbide paper. This surface was ached with 37% phosphoric acid for 30 second, and sealant filled gelatin capsule(3㎜ diameter) was attached to this surface. After immersion in 37% distilled water for 24 hours, shear bond properties were measured with a universal testing machine(Zwick 020, Germany) with the cross-head speed of 1㎜/min. From the lid-deflection calve obtained, shear bond strength, displacement at bond failure and elastic modules ratio was calculated. For biaxial fracture strength test, diameter of 10㎜ and thickness of 2㎜ specimens were made with the same materials as in bonding test. After immersion in 37℃ distilled water for 24 hours, biaxial fracture properties were measured with a universal testing machine(Zwick 020, Germany) with the cross-head speed of 0.5㎜/min. From this experiment, the following results were obtained. 1. The shear bond strength of unfilled HP to enamel surface was 13.870㎫, and those after filler incorporation were 18.956-19.684㎫. 2. The shear bond strength to enamel surface increased significantly after incorporation of filler with the ratio of 10, 30 and 50 wt.%(p<0.05), and the incorporation ratio did not influence on the shear bond strength(p>0.05). Silane treatment of the filler did not influenced on the shear bond strength(p>0.05). 3. The biaxial fracture strength of TM was 170.69㎫, and this was significantly higher than that of unfilled HP(p<0.05). Incorporation of the filler with the ratio of 10, 30 and 50 wt.% resulted in significantly lower biaxial fracture strength compared with that of unfilled HP(p<0.05). 4. In HP with the incorporation of filler 10 or 30 wt.% group, the biaxial fracture strength of silane coated and not-coated filler group was significantly different(p<0.05).

The Performance of Anaerobic Co-digester of Swine Slurry and Food Waste

윤영만,김현철,유정숙,김승환,홍승길,김창현 한국토양비료학회 2011 한국토양비료학회지 Vol.44 No.1

In order to assess the performance of co-digester using pig slurry and food waste at the farm scale biogas production facility, the anaerobic facility that adopts the one-stage CSTR of 5 m^3 day^-1 input scale was designed and installed under the conditions of the OLR of 2.33 kg m^-3 day^-1 and HRT of 30 days in an pig farmhouse. Several operation parameters were monitored for assessment of the process performance. The anaerobic facility was operated in three stages to compare the performance of the anaerobic co-digester. In the Stage I, that was fed with a mix of pig slurry to food waste ratio of 7:3 in the input volume, where input TS content was 4.7 (± 0.8) %, and OLR was 0.837-1.668 kg-VS m-3 day-1. An average biogas yield observed was 252 Nm^3 day^-1 with methane content 67.9%. This facility was capable of producing an electricity of 626kWh day^-1 and a heat recovery of 689 Mcal day^-1. In Stage II, that was fed with a mixture of pig slurry and food waste at the ratio of 6:4 in the input volume, where input TS content was 6.9 (± 1.9) %, and OLR was 1.220-3.524 kg-VS m^-3 day^-1. The TS content of digestate was increased to 3.0 (± 0.3) %. In Stage III, that was fed with only pig slurry, input TS content was 3.6 (± 2.0) %, and OLR was 0.182-2.187 kg-VS m^-3 day^-1. In stage III, TS and volatile solid contents in the input pig slurry were highly variable, and input VFAs and alkalinity values that affect the performance of anaerobic digester were also more variable and sensitive to the variation of input organic loading during the digester operation. The biogas produced in the stage III, ranged from 11.3 to 170.0 m^3 day^-1, which was lower than 222.5-330.2 m^3 day^-1 produced in the stage II.

구강병으로 인한 학업손실실태와 그 연관요인에 관한 연구

윤영만,이흥수 원광대학교 치의학연구소 2002 圓光齒醫學 Vol.11 No.2

To prepare basic data for oral health promotion of elementary and middle school students through the survey of the status of school loss on account of oral diseases and the examination of the related factors, a questionnaire survey was conducted for 3,080 students. School loss was investigated based on the experiences of absences and leaving school early, which had happened from oral diseases. Also the restricted activities related with schoolwork such as dining and sleeping were surveyed. The independent variables were oral health behaviors and socioeconmic factors such as sex, age of their parents, education level of their fathers, family income. Factors related with school loss and the restricted activities were analyzed by the multiple logistic regression method. The results of this study were as follows. 1. The 2.37% of students were absent on account of oral disease at elementary and midlde school. Also, the annual average days of absence and early leaving school for elementary school students were 0.05, while the average days for middle school students were 0.07. 2. The rate of students' restricted activity were 39.1% at elementary school and 55.7% at middle school. 3. The elementary students whose mothers are employed showed higher probability of absence due to oral diseases than the students whose mothers are unemployed. 4. The elementary students who live in rural regions showed higher probability of absence and restricted activities on account of oral diseases than the students who live in urban regions. 5. School loss of middle school students was correlated to a load of schoolwork and score of schoolwork. 6. Middle school students who do not trust oral treatment showed higher probability to experience the restricted activities due to oral diseases than the students who trust in it.

구강병으로 인한 학업손실실태와 그 연관요인에 관한 연구

윤영만,이흥수 대한구강보건학회 2002 大韓口腔保健學會誌 Vol.26 No.3

To prepare basic data for oral health promotion of elementary and middle school students through the survey of the status of school loss on account of oral diseases and the examination of the related factors, a questionnaire survey was conducted for 3,080 students, School loss was investigated based on the experiences of absences and leaving school early, which had happened from oral diseases. Also the restricted activities related with schoolwork such as dining and sleeping were surveyed. The independent variables were oral health behaviors and socio-economic factors such as sex, age of their parents, education level of their fathers, family income. Factors related with school loss and the restricted activities were analyzed by the multiple logistic regression method. The results of this study were as follows. 1. The 2.37% of students were absent on account of oral disease at elementary and middde school. Also, the annual average days of absence and early leaving school for elementary school students were 0.05, while the average days for middle school students were 0.07. 2. The rate of students' restricted activity were 39.1% at elementary school and 55.7% at middle school. 3. The elementary students whose mothers are employed showed higher probability of absence due to oral diseases than the students whose mothers are unemployed. 4. The elementary students who live in rural regions showed higher probability of absence and restricted activities on account of oral diseases than the students who live in urban regions. 5. School loss of middle school students was correlated to a load of schoolwork and score of schoolwork. 6. Middle school students who do not trust oral treatment showed higher probability to experience the restricted activities due to oral diseases than the students who trust in it.

역해석을 이용한 가시설공사 현장관리 시스템 개발

윤영만 한국재난정보학회 2019 한국재난정보학회 논문집 Vol.15 No.4

연구목적: 본 연구에서는 안전한 가시설 공사를 위해서 현장에서 수행하고 있는 계측관리 결과를 현장 관리자와 구조검토자가 공유하여 실시간 의사결정을 이용한 빠른 현장대처가 가능한 시스템을 개발하 고자 한다. 연구방법: 계측시스템과 가시설 구조검토시 반영하는 역해석 기법을 동시에 이용하여 계측 결과로부터 시공상태의 안전성을 파악하고 공사중 발생할 수 있는 위험요인을 판단하여 시공중 선제 적 대응할 수 있는 가시설 공사중 지반물성치 및 기후변화의 이변성에 대응하는 시스템을 도입하였다. 연구결과: 현장여건과 설계 물성치의 불일치 및 예상치 못한 하중 및 외기환경으로 설계에서 예측한 설 계결과와 계측결과의 차이 발생에 대처할 수 있는 SUNEX 프로그램의 역해석 알고리즘을 개발하고 계 측결과와 해석결과가 일치하는 과정을 확인하는 안전관리시스템을 개발하였다. 결론: 실시간 계측결 과 값을 수집하여 외부서버 및 안전관리 시스템 프로그램과 통신할 수 있는 게이트웨이를 제작하여 개 발한 안전관리 시스템에서 실시간으로 해석결과 값과 비교가 가능하도록 하여 현장에서 발생할 수 있 는 위험요인에 대한 선제적 대응이 가능하도록 하였다. Purpose: The purpose of this study is to develop a system that enables quick on-site response using real-time decision-making by sharing the results of measurement and management performed in the field for safe temporary construction. Method: It is possible to take preemptive responses during construction by identifying the safety factors of construction conditions from measurement results and determining the risk factors such as soil properties and variability of climate change that can occur during construction by simultaneously using the back analysis method reflected in the measurement system and structural review. Result: we developed a back analysis algorithm of the SUNEX program to cope with the discrepancies between the design results and measured results due to inconsistency between site conditions and design properties, unexpected loads, and outdoor environment. The process of matching the measurement result with the analysis result can be confirmed in the safety management system. Conclusion: Gateway was used to communicate with real-time measurement results and safety management system program. It was made possible to preemptively respond to risk factors that may occur in the field.

저선량 ${\gamma}$ 선 조사가 배추와 무 종자의 발아와 양분흡수에 미치는 영향

윤영만,김남범,김재성,김정규,Yoon, Young-Man,Kim, Nam-Bum,Kim, Jae-Sung,Kim, Jeong-Gyu 한국환경농학회 1999 한국환경농학회지 Vol.18 No.4

배추와 무의 영양생리에 대한 저선량${\gamma}$선에 의한 자극작용의 영향을 파악하고자 1998년산 흑진주배추, 1995년산 서림엇갈이배추, 1998년산 청운무 종자에 1에서 10Gy의 저선량 ${\gamma}$선을 조사하고 생육시기에 따른 생장량과 무기양분의 변화를 분석하였다. 공시된 배추품종들은 조사선량의 증가에 따라서 발아율과 건물생산량이 증가하는 경향을 보였다. 건물생산의 증가는 흑진주배추에서 가장 현저하여 10Gy 처리구에서 143%로 증가되었고, 서림엇갈이배추는 10Gy에서 138%로 증가하였다. 청운무는 ${\gamma}$선 조사에 따른 발아율과 건물생산량의 일관된 경향성을 보이지 않았다. 무기영양소들의 함량변화는 선량-반응 곡선의 ${\gamma}$ 또는 ${\delta}$형을 나타내 ${\gamma}$선에 의한 자극효과가 일부처리구에서 나타나기는 하였지만 일반적 현상이라고 인정하기 어려웠다. 따라서 저선량 ${\gamma}$조사가 배추와 무의 영양생리에 미치는 영향을 정확하게 파악하기 위한 연구결과의 집적이 필요할 것으로 판단된다. To investigate hormetic effect of low dose ${\gamma}$-ray on the uptake of mineral nutrients in Chinese cabbage (Brassica campestris var. Hekjinju var. Surim and) and radish (Raphanus sativas var. Chung-un), seeds of these plants were irradiated with the dose of 1 to 10 Gy. Germination rate and dry weight were examined at pot experiment in greenhouse. Samples for analysis of mineral nutrient were harvested at 17 days and at 59 days after seedling and were analyzed by ICP. Brassica campestris varieties showed higher germination rate and dry weight production with increasing ${\gamma}$ ray dose. Dry weight of Hekjinju Surim and were 143% and 138% at 10Gy dose. respectively. There was no tendency in germination rate and dry weight production for Raphanus sativas var. Chung-un with ${\gamma}$-ray irradiation. The pattern of mineral nutrient content of these plants showed ${\gamma}$ or ${\delta}$ type of dose-reaction curve with no siginificant. This investigation suggests that the more results can be required to understand the hormetic effect of low dose ${\gamma}$ ray on the uptake of mineral nutrient for these plants.

일본 바이오매스 활용 정책 및 기술현황

윤영만,유호천,김창현,최은희,윤성이,Yoon, Young-Man,Yoo, Ho-Chun,Kim, Chang-Hyun,Choi, Eun-Hee,Yoon, Sung-Yee 한국유기농업학회 2012 韓國有機農業學會誌 Vol.20 No.4

Based on the general policy called "Green Growth", the Korean government planed to establish a biomass town in South Korea in order to recover energy from organic waste and to substitute for fossil fuel at rural region. Technical and financial support for the establishment of biomass town was insufficient so far. There are some policies to support biomass town establishment, however financial support from several Korean ministries seemed not to have been used efficiently. Some policies are planned excessively so that they cannot be realized on time. Therefore, there is a need to analyze the status of biomass utilization technology and policy in Japan from the point of view of an external biomass expert, since biomass utilization technology and policy of Japan take good achievement during the many developed countries. For the analyzing of technology and policy in Japan, literatures concerned biomass management policy and biomass town design were collected by visiting Japan Ministry of Agriculture, Forestry and Fisheries and interview of public officials in charge was carried out. There are several implications for the promotion of Korean policy concerned with biomass utilization and biomass town establishment.

국내 바이오매스 이용 실태와 활성화 방안

윤영만 한국농촌경제연구원 2014 세계농업 Vol.162 No.-

유리섬유복합소재를 이용한 지중매설형 승하강식 홍수방지 벽체구조물

윤영만 한국재난정보학회 2013 한국재난정보학회 논문집 Vol.9 No.4

제방 월류방지 대체공법으로 전도식, 부력식 홍수방지벽을 국내ㆍ외에서 개발하는 실정이다. 그러나, 사전점검 불가 및 유지관리 문제점이 있어 본 연구에서는 국내ㆍ외 최초로 경량 재질이면서 강도가 우수한 유리섬유복합소재를 이용한 승하강식 홍수방지 벽체구조물을 연구ㆍ개발하였다. 개발된 홍수방지 벽체구조물은 수치해석을 통해 구조적 안정성과 함께 현장 적용성을 제시하여 공사비를 약 87%~95%로 감소시키고 벽체구조물 내부에 고무지수부재를 설치하여 차수성이 확보되는 것을 확인하였다.