Kr-85 has a half-life of 10.7 years and it stays in the atmosphere for a long time. However it does not accumulate as an noble gas but only emits beta particles. Therefore its contribution to environmental radiation dose is lower than any other radionuclides. Kr-85 is one of the main fission products produced by nuclear fission reaction and artificial radionuclide that does not exist in nature. For these reasons, monitoring Kr-85 from the atmosphere is meaningful so that the nuclear-related facilities are recommended to control and regulate environmental emissions. Post Irradiation Examination Facility (PIEF) which located in KAERI is a facility that conducts various material and chemical experiments using the irradiated nuclear fuels. Therefore, various radionuclides can present in gaseous effluent including Kr-85. To prevent the environmental hazards and guarantee the radiation safety of the public, nuclear facilities are recommended to be equipped with stack radiation/radioactivity monitoring system, so that the Kr-85 concentration in gaseous effluent is controlled within the regulatory criteria. Particularly, the Kr-85 concentration of gaseous effluent is commonly monitored by the stack monitoring system connected to the process ventilation system from the hot cell. The monitoring system supply the information such as beta count rate, dose rate and flow rate, etc. Due to the concentration of Kr-85 in gaseous effluent is subject to regulatory guide lines, a systemized procedure for calculating Kr-85 concentration of the stack exhaust is necessary. Furthermore, the emission should be monitored whether it satisfies the regulatory standard or does not. This paper performed discussion on the process of calculating the concentration of Kr-85 in the gaseous effluent of PIEF stack from the monitoring system (NGM209, MGP), and the amount of Kr- 85 over the last 2 years emissions was calculated. In addition to calculating effluent rate of radioactive Kr-85, the Minimum Detectable Concentration (MDC) and Decision Threshold (SD) were calculated. As a result, the calculated Kr-85 concentration was below the SD during the entire period. It is considered that there are no environmental emissions of Kr-85.
Development, availability and users’ participation in the information service of agricultural food sector is slower than that of other sectors in Korea. This phenomenon comes from the lack of development strategies and comparative analyses with other sectors, as well as the agricultural food industry’s own characteristics which is developed based on the offline market.
In this research, we will discuss about how to improve the public information service of agricultural food sector based on the example of establishing service improvement strategy by the most representative Okdab. In this research, we have drawn the following implications for development strategy of Okdab service based on three core keywords derived from benchmarking KOSIS.
Three core subjects for upgrading public information service are ‘analysis information with expertise and differentiation,’ ‘user cooperation-oriented platform,’ and ‘intuitive nd effective UX,’ and to strength B.I. as an integrated information service of agricultural food sector, we need to identify the users’ satisfaction and needs for the existing service, establish an optimized operating strategy on a short-term, mid-term and long term bases, and implement them in a positive way. Based on this positive action, it can become a trustworthy information service for the users, and we can expect the improvement of the users’ recognition for its consistent usability and efficiency.
The use of continuous welded rail is increasing because of its many advantages, including vibration reduction, enhanced driving stability, and maintenance cost savings. In this work, two different types of continuous welded rails were examined to determine the influence of repeated wheel-rail contact on the crystal structure, microstructure and mechanical properties of the rails. The crystal structure was determined by x-ray diffraction, and the microstructure was examined using optical microscopy and scanning electron microscopy. Tensile and microhardness tests were conducted to examine the mechanical behaviors of prepared specimens taken from different positions in the cross section of both newly manufactured rail and worn rail. Analysis revealed that both the new and worn rail had a mixed microstructure consisting of ferrite and pearlite. The specimens from the top position of each rail exhibited decreased lamella spacing of the pearlite and increased yield strength, ultimate tensile strength and hardness, as compared with those from other positions of the rail. It is thought that the enhanced mechanical property on the top position of the worn rail might be explained by a mixed effect resulting from a directional microstructure, the decreased lamella spacing of pearlite, and work hardening by the repeated wheel-rail contact stress.
목적: 본 연구에서는 원리가 다른 두 수차계 Hartmann Shark Aberrometer와 Retinoscopic Aberrometer로 측정한 연령에 따른 수차의 평균의 차이에 대한 유의성을 검증하고 상관관계를 비교하였다.
방법: 원리가 다른 두 수차계 Hartmann Shark Aberrometer (KR9000-PW®, Topcon, Tokyo, Japan와 Retinoscopic Aberrometer (OPD Scan®, NIDEK Co Ltd, Gamagori, Japan)를 이용하여 측정한 연령에 따른 안구전체, 각막, 수정체를 포함한 내부의 총고위수차, 코마수차 그리고 구면수차의 평균의 차이에 대한 유의성을 검증하고 두 기기로 측정한 수차 값 간의 상관관계를 비교하였다.
결과: 두 기기 간의 안구전체의 총 고위수차량은 10대와 20대만 통계적으로 유의하게 나타 났고(10s : p<0.001, 20s : p=0.002) 코마수차는 40대와 60대에서 통계적으로 유의하게 나타났으며(40s : p=0.004, 60s : p=0.021) 구면수차에서는 20에서 40대까지와 60대에서 통계적으로 유의하였다(20s : p=0.009, 30s : p<0.001, 40s : p=0.041, 60s : p<0.001). 각막의 총 고위수차량은 모든 연령대에서 p=0.001로 유의하게 나타났으나 코마수차는 모 두 p<0.05으로 통계적으로 유의하지 않았다. 구면수차는 10와 30대 그리고 60대에서 통계 적으로 의미있게 나타났다(10s : p=0.001, 30s : p=0.001, 60s : p=0.015). 수정체를 포함한 내부의 총 고위수차량은 60대(60s : p=0.232)를 제외하고 10대에서 50대까지 통계적으로 유의하였으나(10s : p=0.025, 20s : p<0.001, 30s : p=0.005, 40s : p<0.001, 50s : p=0.014) 코마수차에서는 모두 통계적 의미가 없었다. 구면수차에서는 모든 연령대에서 통계적으로 유의하였다(10s : p<0.001, 20s : p<0.001, 30s : p=0.001, 40s : p<0.001, 50s : p=0.008, 60s :p<0.001). 안구전체와 각막의 총 고위수차, 코마수차, 구면수차 및 수정체를 포함한 내부의 총 고위수차, 코마수차는 양의 상관관계를 보였으며 수정체를 포함 한 내부의 구면수차만이 음의 상관관계를 나타내었다. 수정체를 포함한 내부의 총고위수차를 제외하고 모두 통계적으로 유의하였다.
결론: 본 연구를 통해 서로 다른 원리의 Hartmann Shark Aberrometer와 Retinoscopic Aberrometer로 수차를 측정함에 있어서 차이점을 가지고 있기 때문에 각 기계의 특징과 차이를 이해하고 분석하여 임상적 정확성을 위해 계속적인 검증 연구가 필요할 것으로 사료 된다.
목 적: KR-8100P, Nvision K-5001, KR-1W로 측정한 굴절이상도를 자각식 굴절검사와 비교하여 정확 도를 평가하였다.
방 법: 근시성 난시안인 20 ~ 29세 성인 42명(84안, 23.90±2.39세)을 대상으로 내부형 자동굴절계 (KR-8100P), 개방형 자동굴절계(Nvision K-5001), 파면수차계(KR-1W)를 이용하여 굴절이상을 각각 측정 하였고, Power vector를 이용하여 등가구면굴절력을 나타내는 M 성분과 원주굴절력 J0 와 J45 성분으로 변 환하여 분석하였다. 검사기기 측정값의 정확도는 자각식 굴절검사를 기준으로 각각의 기기에서 측정한 값을 비교 분석하였다.
결 과: KR-8100P와 자각식굴절검사의 M, J0, J45 각각의 차이값의 평균은 -0.34±0.42 D, 0.06±0.22 D, -0.08±0.15 D로 모든 성분에서 유의한 차이가 있었고(p<0.05), Nvision K-5001과 자각식굴절검사의 M, J0, J45 차이값은 0.20±0.47 D, -0.03±0.22 D, -0.01±0.16 D로 M 성분에서 차이가 있었고(p<0.05), J0, J45 에서는 차이가 없었다(p=0.17, p=0.68). KR-1W와 자각식굴절검사의 M, J0, J45 차이값은 -0.14±0.39 D, -0.02±0.18 D, -0.02±0.14 D로 M 성분은 차이가 있었고(p<0.05) J0 와 J45 에서는 차 이가 없었다(p=0.43, p=0.05). 각각의 기기로 측정한 M, J0, J45 성분들의 정확성계수는 KR-8100P에서는 0.823, 0.431, 0.294, Nvision K-5001에서는 0.921, 0.431, 0.313, KR-1W에서는 0.764, 0.352, 0.274로 나타났다.
결 론: 자각식 굴절검사를 기준으로 비교한 자동굴절계의 정확도는 KR-1W가 KR-8100P와 Nvision K-5001보다 더 높았고, 검사값의 차이가 통계적으로 유의한 것으로 나타났지만 임상적으로 판단할 때 차이 가 있다고 할 수 없는 정도이기 때문에 자동굴절계는 모두 자각식 굴절검사를 위한 예비검사에 적합하다고 생각된다.
A rod-shaped, Gram-negative chlorpyrifos-methyl (CM) degrading bacterium (designated strain KR200) was isolated from a Korean rice paddy soil and was further tested for its substrate specificity against 11 insecticides and its sensitivity against eight commercial antibiotics. Based on morphological, biochemical, and molecular characteristics, this bacterium showed greatest similarity to members of the order Flavobacteriales and was shown to be most closely related to members of the Chryseobacterium proteolyticum group. Strain KR200 hydrolyzed CM to 3,5,6-trichloro-2-pyridinol (TCP) but could not degrade TCP further. The isolate was also able to degrade chlorpyrifos, dicrotophpos, monocrotophos, and carbaryl at 300 μg mL–1 but diazinon, dimethoate, and furathiocarb at 100μg mL–1. The ability to degrade CM was found to be encoded on the chromosome. Genes encoding resistance to amphotericin B, polymixin B sulfate, and tetracycline were also located on the chromosome. This bacterium merits further study as a potential biological agent for the remediation of soil, water, or crop contaminated with organophosphorus (OP) compounds because of its greater biodegradation activity and its broad specificity against a range of OP insecticides.
Based on the Presidential Instruction No. 5 of 2005 concerning the Empowerment of the shipping industries and followed by Shipping Law No. 17/2008, Indonesia has implemented and adopted the cabotage principle.
낙후된 선박건조 및 검사기술, 해양안전에 대한 관심, 해양안전 관리체계 등이 미흡한 개발도상국의 경우 해양사고의 빈도가 높으며, IMO 협약 등에서 강제적으로 요구되는 해사안전분야 시스템 중 많은 부분에 대 해 개발도상국들이 기술력 부족 등으로 제대로 대처하지 못하고 있는 실정에 있다. 이와 관련한 국제적 해사안전 분야에서 주요 해양선진국은 국가 정책에 따라 개발도상국에 대한 공적개발원조사업을 추진해온 바 있으며, 국제 적인 관계 및 국가적 실익 추구를 위해 조선해양 관련 ODA 사업 규모를 꾸준히 증가시키는 추세에 있다. 우리나 라는 조선해양 강국으로서 세계최고 수준의 선박 설계, 건조 및 검사 기술을 보유하고 있으므로, 선박수주량 및 기 술력이 취약한 개도국을 대상으로(특히 동남아시아 국가들) 어선을 포함한 선박의 설계, 건조 및 검사의 기술이전 이 가능한 실정이다. 한국선급에서는 국토해양부 해양과학기술연구개발사업 ‘개발도상국 해사안전시스템 구축 협력 사업’에서 ‘선박설계 및 건조기술지원 국제협력 방안’과 관련한 과제를 인도네시아 선급(BKI)을 대상으로 추진하고 있다. 그 일환으로 선박건조에 적용하여야 하는 IACS에서 타선급들과 공동개발한 CSR, IMO에서 제정한 SOLAS, MARPOL 및 STCW 등 각종 국제협약을 데이터베이스화하여 개발한 SeaTrust-CSR, SeaTrust-ISTAS와 KR-CON에 관한 내용 및 온실가스 저감을 위한 친환경 선박의 에너지 효율향상 기술에 대한 기술 이전을 위한 지원 절차 및 방법들을 설명한다.
The Organophosphorus pesticides are widely used for agricultural and domestic purposes due to their relatively low persistence in the environment. Chlorpyrifos-methyl (CM) is used at a rate of over 14 million pounds per year in US agriculture, ranking it as the second most heavily used pesticide. This study aimed at isolating bacteria from soil and determining their ability to degrade CM and identify the intermediates in culture broth. Bacteria capable of degrading CM was isolated by enrichment culture. Chryseobacterium sp. strain KR200 degraded CM up to 91.58% in 7days. Studies with CM in liquid culture of Chryseobacterium sp. strain KR200 demonstrated that the isolate hydrolyzed CM to 3,5,6-trichloro-2-pyridinol, and utilized this compound for growth and energy. We performed SDS-PAGE and two-dimensional gel electrophoresis and identified proteins whose expression pattern is affected by CM using mass spectrometry. The results revealed various proteins that can be grouped according to their respective cellular function. These results highlight the potential of this bacterium to be used in the clean up of contaminated pesticide waste in the environment.