• Title/Summary/Keyword: 위험 속도 선도

Search Result 92, Processing Time 0.021 seconds

Measurement of Environmental Radiation Using Medical Scintillation Detector in Well Counter System (의료용 우물형 섬광계수기를 이용한 환경 방사선 측정)

  • Lyu, Kwang Yeul;Park, Yeon-joon;Kim, Min-jeong;Ham, Eun-hye;Yoon, Ji-yeol;Kim, Hyun-jin;Min, Jung Hwan;Park, Hoon-Hee
    • Journal of radiological science and technology
    • /
    • v.38 no.4
    • /
    • pp.337-345
    • /
    • 2015
  • After the Fukushima nuclear accident in 2011, concerns about radiation by people are increasing rapidly. If people could know how much they will be exposed by radiation, it may help them avoiding it and understand what exactly radiation is. By doing this, we were helping to reduce the anxiety of radiation contamination. In this study, we have researched figures of radioactivity with 'Captus-3000 thyroid uptake measurement systems' in well counter detector system. The materials were measured with Briquette, Shiitake, Pollock, Button type battery, Alkaline battery, Topsoil, Asphalt, Gasoline, Milk powder, Pine, Basalt stone, Pencil lead, Wasabi, Coarse salt, Tuna(can) Cigar, Beer, and then we categorized those samples into Land resources, Water resources, Foodstuff and Etc (Beer classified as a water resources has been categorized into Foodstuff). Also, we selected the standard radiation source linear 137Cs to measure the sensitivity of well counter detector. After that, we took cpm(counter per minute) for the well counter detector of thyroid uptake system's sensitivity. Then we compared the results of each material's cpm and converted those results to Bq/kg unit. There were a little limitation with the measurement equipment because it has less sensitivity than other professional equipment like 'High purity germanium radiation detector'. Moreover, We didn't have many choices to decide the materials. As a result, there are macroscopic differences among the rates of material's spectrum. Therefore, it had meaningful results that showed how much each material had emitted radiation. To compare the material's cpm with BKG, we've compounded their spectrums. By doing that, we were able to detect some differences among the spectrums at specific peak section. Lastly, Button type battery, Alkaline Battery, Briquette, Asphalt and Topsoil showed high value. There were classified emitting high radiation Group A and emitted lower radiation Group B. The Group A, alkaline battery showed higher rate of radiation by 7.67 %, and Button type battery was yield 4.65 % higher rate than BKG. Additionally, Asphalt (8.03 %), Topsoil (3.76 %), Briquette (7.46 %) were yield for higher values. Several samples of the daily supplies were yield little higher, but it seems safe to use in daily lives. In the case of the 'Foodstuff', all of the samples were safe and they were under the radiation limits of the Ministry of Food and Drug Safety for Food; thus, we highly recommend this study to you as a reference of common daily routine.

Microbiological Quality and Growth and Survival of Foodborne Pathogens in Ready-To-Eat Egg Products (즉석섭취 알 가공품의 미생물학적 품질 및 주요 식중독 균의 증식·생존 분석)

  • Jo, Hye Jin;Choi, Beom Geun;Wu, Yan;Moon, Jin San;Kim, Young Jo;Yoon, Ki Sun
    • Journal of Food Hygiene and Safety
    • /
    • v.30 no.2
    • /
    • pp.178-188
    • /
    • 2015
  • Microbial quality of baked egg products was evaluated by counting the levels of sanitary indicative bacteria (aerobic plate counts, coliforms, and E. coli), L. monocytogenes and Salmonella spp. at the critical control points (CCPs) of manufacturing process. In addition, the survival and growth of foodborne pathogens in various egg products (cheese, tuna, tteokgalbi, pizza omelets, baked egg, and steamed egg) were investigated at 4, 10, and $15^{\circ}C$. The contamination level of aerobic plate counts decreased from 4.67 log CFU/g at CCP 1 to 0.56 log CFU/g at CCP 3 in baked egg products. No coliforms and E. coli were detected at all CCPs. Although L. innocua and Salmonella spp. were identified at CCP 1, no L. monocytogenes and Salmonella spp. were detected in the final products. The contamination levels of aerobic plate counts and coliforms in egg strips and number of aerobic plate counts in Tteokgalbi omelet are higher than the microbiological standard of processed egg products. At $10^{\circ}C$, the growth of all pathogens was not prevented in omelet and baked egg, but the populations of S. Typhimurium and E. coli were reduced in steamed egg at $10^{\circ}C$, regardless of the presence of other pathogens. The growth of L. monocytogenes was faster than that of S. Typhimurium and E. coli in omelet. More rapid growth of S. Enteritidis than S. Typhimurium was observed in egg products, indicating the greater risk of S. Enteritidis than S. Typhimurium in egg products.