The safe, efficient and cost-effective decommissioning and dismantling of radioactive facilities requires the accurate characterization of the radionuclide activities and dose rate environment. And it is critical across many nuclear industries to identify and locate sources of radiation accurately and quickly. One of the more challenging aspects of dealing with radiation is that you cannot see it directly, which can result in potential exposure when working in those environments. Generally, semiconductor detectors have better energy resolution than scintillation detectors, but the maximum achievable count rates are limited by long pulse signals. Whereas some high pure germanium detectors have been developed to operate at high count rates, and these HPGe detectors could obtain gamma-ray spectra at high count rates exceeding 1 Mcps. However, HPGe detectors require cooling devices to reduce the leak currents, which becomes disadvantageous when developing portable radiation detectors. Furthermore, chemicalcompound semiconductor detectors made of cadmium telluride and cadmium zinc telluride are popular, because they have good energy resolution and are available at room temperature. However, CdTe and CZT detectors develop irradiation-induced defects under intense gamma-ray fields. In this Review, we start with the fundamentals of gamma rays detection and review the recent developments in scintillators gamma-ray detectors. The key factors affecting the detector performance are summarized. We also give an outlook on the field, with emphasis on the challenges to be overcome.

이 연구는 스마트 온실의 온습도 데이터를 수집하고, 그 환 경 요인들 간의 상관관계를 분석하여 스마트 온실 환경관리의 기초자료를 제공하고자 수행되었다. 스마트팜 시스템이 도입된 토경 방식의 OS 온실과 암면 배지경 방식의 KB 온실을 대 상으로 기온, 근권온도, 상대습도의 항목에서 매일 24시간의 데이터를 수집하였고, 이중 최고와 최저, 일평균, 주간 평균, 야간 평균, 일교차의 여섯 가지로 세분하여 정리한 후 두 온실 간의 차이와 기온과 근권온도의 상관관계를 분석하였다. 장미의 생육적온은 주간, 야간, 일교차는 이며, 근권온도는, 습도 는 95% 미만을 유지하는 것이 좋다. 두 온실의 실제 환경과 장미의 적정 환경 조건을 비교했을 때, 주간 기온은 OS 온실 에서 5개월 간, KB 온실에서 7개월 간 적정 수준(24~27˚C)을 유지하였다. 야간 기온은 두 온실 모두 2개월간 적정 수준 (15~18˚C)을 유지하였고, 일교차는 OS 온실에서 6개월간, B 온실은 9개월 간 적정 수준(약 10˚C)에 근접하였다. 근권온도 는 OS 온실에서 10개월, KB 온실에서 5개월간 적정 수준 (20~25˚C)을 유지한 반면, 상대습도는 두 온실 모두 연중 적정 범위 내에 들었다. 기온과 근권온도의 상관관계를 분석한 결 과, OS 온실은 최고 온도, 평균 온도, 주간 온도, 야간온도에 서는 뚜렷한 상관관계를, 최저온도와 일교차에서는 약한 상관 관계를 보였으며, KB 온실에서는 전 영역에서 매우 강한 직선 적 비례 관계를 보였다. 결론적으로 토경재배를 실시하는 OS 온실이 고설식 암면배지경을 실시하는 KB 온실에 비해 근권 온도가 기온의 영향을 덜 받았으며, 완충능력이 높은 토경재 배에서는 기온의 영향을 덜 받는다고 볼 수 있다.

Ochratoxin A (OTA) is one of the most important mycotoxins owing to its widespread occurrence and toxicity including nephrotoxicity and potential carcinogenicity to humans. Since OTA is stable under most food processing conditions, OTA has been detected not only in a wide range of agricultural commodities such as cereal grains but also their processed products. Nonetheless, it is known that significant reduction of OTA may be achieved under higher temperature and alkaline conditions. In this study, the effects of retorting cooking process on the stability of OTA in spiked (20 μg/kg of dry weight basis) rice and oat porridge (10% solid content; w/v) in the presence and absence of baking soda was investigated using a laboratory horizontal steam retort system. The samples were heated in a pot at 85°C central temperature until it becomes gelatinized, packed in retort pouched, and heat-processed in pressurized retort machine (at 121°C for 25 min) followed by drying in 50°C oven overnight. Samples were analyzed for OTA by high-performance liquid chromatography with a fluorescence detector (HPLC-FLD). The reduction of OTA in retorted rice and oat porridge were 54% and 17%, respectively, while greater reduction of OTA was observed at increased amount of baking soda. The reduction of OTA in retorted rice porridge with 0.5% and 1% baking soda were 55% and 66%, respectively. In the retorted oat porridge, reduction of OTA was also evident to result in 30% and 48% with 0.5% and 1.0% of added baking soda, respectively. These results suggest that OTA in rice and oat may be reduced significantly by retorting process. In addition, added baking soda may positively impact the reduction of OTA.

Ochratoxin A, which is frequently detected in cereals and infant diets worldwidely, is a mycotoxin to damage mainly the kidney and liver. Because ochratoxin A is highly thermostable compound. it is necessary to study ways of reducing level of ochratoxin A by controling processing steps. However, food processes, including extrusion, expansion, roasting, and steam cooking, which are used in order to mitigate the contents of ochratoxin A, are known to produce polycyclic aromatic hydrocarbons, which are generated from radicals decomposed by pyrolysis. Therefore, this study analyzed the levels of 4 polycyclic aromatic hydrocarbons, benz (a) anthracene, chrysene, benzo (b) fluoranthene and benzo (a) pyrene in rice-based products made in high pressure and heating process. Rice samples were finely ground, and homogenized samples were alkaline treatement with 1 M KOH/EtOH and extracted with liquid-liquid extraction method using n-hexane. The extracted solution was pretreated with a silica cartridge. The purified solution was dried with nitrogen gas and dissolved in 1 mL of dichloromethane and injected into GC/MSD. We had overall recoveries for 4 polycyclic aromatic hydrocarbons spiked into rice samples ranging from 92.8 to 110.2%. The limit of quantitations of benz (a) anthracene, chrysene, benzo (b) fluoranthene and benzo (a) pyrene in rice-based product were 0.19 ng/g, 0.38 ng/g, 0.51 ng/g, and 0.31 ng/g, respectively. However, these 4 polycyclic aromatic hydrocarbons in all processed rice samples were not detected.