• Title/Summary/Keyword: 방사선품질

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Quality Changes of Kimchi Manufactured with Sanitized Materials by Ozone and Gamma Irradiation during Storage (오존 및 방사선 조사기술 이용 원부재료의 위생화 후 제조한 김치의 저장기간에 따른 변화)

  • Lee, Kyong-Haeng;Byun, Myung-Woo
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.36 no.2
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    • pp.216-221
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    • 2007
  • Microbiological, chemical and sensorial quality changes of kimchi, which was manufactured with sanitized materials by ozone and gamma irradiation, were investigated during storage. The number of total aerobic bacteria in control was increased rapidly by storage and decreased after 10 days of storage. However, the kimchi which was manufactured with materials treated with ozone or gamma irradiation showed a lower rate of increase. The number of lactic acid bacteria was lower in control than in treatments. Gamma irradiation of 3 or 5 kGy showed the lowest change of microbial population in kimchi during storage. pH, acidity and sensory quality were also rapidly changed in control whereas those of ozone or irradiation treated sample was slower. Therefore, cold pasteurization of materials before kimchi manufacturing provide a slower fermentation, resulting into the extension of storage quality for kimchi.

Image quality assessment with dose reduction using high kVp and additional filtration for abdominal digital radiography (디지털 복부방사선검사에서 고관전압과 부가여과판을 사용한 선량감소와 영상평가)

  • Jang, ji-sung;Lee, ho-beom;Choi, kwan-woo
    • Proceedings of the Korea Contents Association Conference
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    • 2018.05a
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    • pp.59-60
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    • 2018
  • 디지털 복부 방사선검사에서 고관전압과 부가필터를 이용한 선량감소가 최근 큰 관심을 받고 있다. 본 연구에서는 복부 방사선 검사에서, 기존 방법(80 kVp without filter)과는 다른 고관전압(92 kVp)과 부가필터(0.1 mm Cu-filter)를 사용하여 적절한 진단학적 영상품질을 유지하면서 상당한 환자 선량을 감소 시켰다. 따라서, 본 연구에 방법을 적절하게 이용하면 진단학적 영상품질을 유지하며 환자선량도 감소하는데 유용하리라 사료된다.

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Analysis and Investigation for the Status of Radiation Therapy QA in Korea (국내 방사선치료기기의 품질관리 현황조사 및 분석)

  • Lee, Sang-Hoon;Kim, Ju-Ree;Cho, Sam-Ju;Cho, Kwang-Hwan;Lim, Chun-Il;Kim, Hyeog-Ju;Huh, Hyun-Do;Shin, Dong-Oh;Kwon, Soo-Il;Choi, Jin-Ho
    • Progress in Medical Physics
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    • v.21 no.2
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    • pp.223-231
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    • 2010
  • We have taken surveys about total 72 departments of radiation oncology which is performing the treatment with linear accelerator and brachytherapy unit in Korea. The survey was included the research about the linear accelerator, brachytherapy, Also, we surveyed the various performance (QA period, manpower, time) of quality control for understanding of efficiency. The survey results show that the QA test of daily and weekly are almost same comparing to USA and Europe but the QA performance of monthly and yearly in Korea are 15.5 which is less than USA and Europe recommended QA item number of 17 to 21. The manpower and QA time in Korea also lower than 50% of USA and Europe recommended because the manpower and QA time limitation in Korea. It will be expected that the manual of quality management in each clinic could be appropriately established when combining the present results with previously published AAPM TG-40 and other protocols.

A Study of Scattered Radiation Effect on Digital Radiography Imaging System (디지털 방사선영상 시스템에서 산란선이 영상 품질에 미치는 영향)

  • Baek, Cheol-Ha
    • Journal of radiological science and technology
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    • v.40 no.1
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    • pp.71-78
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    • 2017
  • Scattered radiation is inherent phenomenon of x-ray, which occurs to the subject (or patient). Therefore it cannot be avoidable but also interacts as serious noise factor because the only meaningful information on x-ray radiography is primary x-ray photons. The purpose of this study was to quantify scattered radiation for various shooting parameters and to verify the effect of anti-scatter grid. We employed beam stopper method to characterize scatter to primary ratio. To evaluate effect on the projection images calculated contrast to noise ratio of given shooting parameters. From the experiments, we identified the scattered radiation increases in thicker patient and smaller air gap. Moreover, scattered radiation degraded contrast to noise ratio of the projection images. We find out that the anti-scatter grid rejected scattered radiation effectively, however there were not fewer than 100% of scatter to primary ratio in some shooting parameters. The results demonstrate that the scattered radiation was serious problem of medical x-ray system, we confirmed that the scattered radiation was not considerable factor of dig ital radiog raphy.

Effect of Irradiation Temperature on Physicochemical and Sensory Properties of Tarakjuk (Milk Porridge) (방사선 조사 온도가 타락죽의 이화학적 및 관능적 품질 특성에 미치는 영향)

  • Han, In-Jun;Song, Beom-Seok;Lee, Ju-Woon;Kim, Jae-Hun;Choi, Kap-Sung;Park, Jeong-Ro;Chun, Soon-Sil
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.40 no.9
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    • pp.1307-1313
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    • 2011
  • This study was conducted to evaluate the effects of irradiation temperature on the physicochemical and sensory properties of Tarakjuk, milk porridge. Tarakjuk was gamma-irradiated at different temperatures of $25^{\circ}C$ (in room), $4^{\circ}C$ (in ice), and $-20^{\circ}C$ (in dry ice) at a dose of 10 kGy, and then autoclaved at $120^{\circ}C$ for 15 min for comparison. pH and Hunter's color value of Tarakjuk were not changed by irradiation regardless of the temperature. However, the TBA (2-thiobarbituric acid) value decreased as irradiation temperature was decreased. The viscosity of Tarakjuk irradiated in dry ice was significantly higher than that irradiated at room temperature and in ice (p<0.05). For the sensory evaluation, there were no significant differences in overall acceptability between non-treated Tarakjuk and that irradiated in dry ice. Flavor pattern analysis using an electronic nose with a SAW (surface acoustic wave) sensor determined that the main peaks at retention times 3.88 and 7.34 sec were related with off-flavor induced by irradiation and unique flavor of Tarakjuk, respectively. These results indicated that irradiation at freezing temperature improved quality deterioration of Tarakjuk by gamma irradiation. However, sensory quality of Tarakjuk irradiated at freezing temperature was still lower than that of non-irradiated Tarakjuk. Therefore, further research is needed to improve the quality of Tarakjuk using combined treatment such as addition of antioxidants and vacuum packaging method.

Study on the Image Quality Comparison between in Digital RT and Film RT (용접부에 대한 디지털 방사선투과영상과 필름 방사선투과영상의 상질 비교에 관한 연구)

  • Park, Sang-Ki;Ahn, Yean-Shik;Gil, Doo-Song
    • Journal of the Korean Society for Nondestructive Testing
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    • v.31 no.4
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    • pp.391-397
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    • 2011
  • Conventional film radiographic test has been generally and widely used in the inspection on the weldment for quality assurance. On the other hand, since the analog RT is well known for typical time and cost consuming method with complex process of inspection, the industry has researched various ways how to improve radiographic test technology. In this study, we verified the fact that digital RT provides a lot more benefit in effectively detecting defects, ever film details, through digital processing of image enhancement, compared to film RT. As a result, we reached conclusion that digital RT is positively able to replace the film RT in industry in part or in whole.

방사선 조사 건고사리의 조리 후 특성

  • 성태화;김미리
    • Proceedings of the Korean Society of Food and Cookery Science Conference
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    • 2003.10a
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    • pp.89-89
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    • 2003
  • 고사리(Pteridium aquilinum)는 봄철에 어린싹을 삶아 물에 담구었다가 먹거나 건조시켜 저장해서 이용하는데 현재 유통되고 있는 건고사리는 수확, 건조 및 저장 중에 비위생적인 관리 둥에 의해 미생물의 중식 및 해충의 발생 등으로 품질이 크게 저하되어 저장상 많은 어려움을 안고 있다. 살균, 살충을 위한 방사선의 식품에의 이용은 그 건전성과 경제적 타당성이 인정되어 여러나라에서 실용화 되고 있다. 방사선 조사된 건고사리는 선행연구에서 재수화성이 증대되었고, 조리에 의한 연화시간이 단축되어 에너지 절감의 효과가 있었다. (중략)

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방사선 조사가 신선 돈육의 특성에 미치는 영향

  • 이윤진;이경애
    • Proceedings of the Korean Society of Food and Cookery Science Conference
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    • 2003.10a
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    • pp.79-79
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    • 2003
  • 돈육은 상업적 조사가 허용되어 있는 대표적 식품으로 FDA는 신선육과 냉동육의 최대조사량을 각각 4.5 kGy, 7 kGy로 규정하고 있다. 돈육에 방사선을 조사하면 수분이 이온화되어 생성된 자유 라디칼이 돈육성분과 반응하게 되어 돈육의 외관, 텍스쳐 등에 변화를 일으킨다. 돈육의 색깔, 냄새 등은 신선 돈육의 구매여부를 결정하는 중요한 특성으로 방사선 조사에 의한 육류의 품질 특성 변화는 조사 돈육의 소비에 많은 영향을 미칠 것으로 생각된다. (중략)

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