• 제목/요약/키워드: Irradiation Dose

검색결과 1,997건 처리시간 0.027초

Effects of Electron Beam Irradiation on Functional and Other Associated Properties of Pork Myofibrillar Salt-Soluble Proteins

  • Koh, Kwang-Hwan;Lee, Sam-Pin;Whang, Key
    • Preventive Nutrition and Food Science
    • /
    • 제11권1호
    • /
    • pp.73-77
    • /
    • 2006
  • Ground pork was irradiated with an electron beam (e-beam) at a dose of 0, 1.5, 3, 5 and 10 kGy and the changes in various functional and other associated properties of salt-soluble proteins extracted from the pork were evaluated. Irradiation did not affect turbidity and the disulfide content of pork salt-soluble protein, but the content of sulfhydryls and the hydrophobocity of salt-soluble protein increased. This indicates that protein degradation occurred when the pork was e-beam irradiated and that the sulfhydryls and hydrophobic moieties buried inside the proteins were exposed to the outside environment. However, these degraded protein molecules did not form large protein aggregates through disulfide bridges. The emulsifying capacity of the pork increased with irradiation, which could be the result from increased hydrophobicity of pork salt-soluble protein. Water holding capacity of pork was not affected bye-beam irradiation.

5-MeV Proton-irradiation characteristics of AlGaN/GaN - on-Si HEMTs with various Schottky metal gates

  • Cho, Heehyeong;Kim, Hyungtak
    • 전기전자학회논문지
    • /
    • 제22권2호
    • /
    • pp.484-487
    • /
    • 2018
  • 5 MeV proton-irradiation with total dose of $10^{15}/cm^2$ was performed on AlGaN/GaN-on-Si high electron mobility transistors (HEMTs) with various gate metals including Ni, TaN, W, and TiN to investigate the degradation characteristics. The positive shift of pinch-off voltage and the reduction of on-current were observed from irradiated HEMTs regardless of a type of gate materials. Hall and transmission line measurements revealed the reduction of carrier mobility and sheet charge concentration due to displacement damage by proton irradiation. The shift of pinch-off voltage was dependent on Schottky barrier heights of gate metals. Gate leakage and capacitance-voltage characteristics did not show any significant degradation demonstrating the superior radiation hardness of Schottky gate contacts on GaN.

Polyvinylidene fluoride의 $^{60}Co$감마선 조사에 의한 구조 변화 (Structural Changes of Polyvinylidene fluoride with $^{60}Co$ $\gamma-ray$ Irradiation)

  • 이청;김기엽;류부형
    • 한국안전학회지
    • /
    • 제19권3호
    • /
    • pp.26-31
    • /
    • 2004
  • The radiation-induced changes taking place in poly(vinylidene fluoride) (PVDF) exposed to $^{60}Co$ $\gamma-ray$ irradiation were investigated in correlation with the applied doses. Samples were irradiated in air at room temperature by $^{60}Co$ $\gamma-ray$ to doses in the range of 200 to 1000kGy. Various properties of the irradiated PVDF were studied using FTIR, differential scanning calorimetry (DSC), gel fraction and elongation. $^{60}Co\gamma-ray$ irradiation was found to induce changes in chemical, thermal, mechanical and structural properties of PVDF and such changes vary depending on the radiation dose.

Modification of Radiation Response in Mice by Panax ginseng and Diethyldithiocarbamate

  • Kim, Sung-Ho;Son, Chang-Ho;Nah, Seung-Yeol;Jo, Sung-Kee;Byun, Myung-Woo;Shin, Dong-Ho
    • 한국수의병리학회:학술대회논문집
    • /
    • 한국수의병리학회 2001년도 추계학술대회 및 정기총회
    • /
    • pp.22-22
    • /
    • 2001
  • We performed this study to determine the effect of Panax ginseng and its fractions on jejunal crypt survival, endogenous spleen colony formation, and apoptosis in jejunal crypt cells of mice irradiated with high and low dose of $\gamma$-irradiation. The radioprotective effect of ginseng was compared with the effect of diethyldithiocarbamate (DDC). Ginseng administration before irradiation protected the jejunal crypts (p<0.005), increased the formation of endogenous spleen colony (p<0.005) and reduced the frequency of radiation-induced apoptosis (p<0.005). (omitted)

  • PDF

건조 향신료 3종에 대한 방사선종별 조사효과 비교 (Comparison of Three Radiation Sources on Quality Properties of Three Dried Condiments)

  • 박경숙
    • 방사선산업학회지
    • /
    • 제8권2호
    • /
    • pp.83-88
    • /
    • 2014
  • Application of X-ray irradiation of dried condiments was studied using commercially prepared dried garlic, onion and welsh onion flakes as model samples. Total load of aerobic microbes (TAM), color differences, and generation of off-flavor were quantified for samples individually irradiated with gamma rays, electrons, or X-rays. TAM load was decreased by irradiation in a dose-dependent manner. The three types of radiation did not differ in the extent of TAM reduction (P>0.05). The samples did not differ in color. Off-flavor was detected from 6 kGy-irradiated samples, regardless of radiation sources. The results indicated that X-ray irradiation could be used for irradiation of dried condiments with the same effects as gamma rays and an electron beam.

방사선 돌연변이 육종기술을 통한 고 아미노산 함유 김(Pyropia yezoensis) 돌연변이 개발 (Development of Pyropia yezoensis Mutant with Improved Amino Acid Content Using Gamma Rays)

  • 이학증
    • 한국수산과학회지
    • /
    • 제54권6호
    • /
    • pp.982-988
    • /
    • 2021
  • Gamma irradiation is one of the simple methods used to induce mutagenesis. Therefore, it is widely used for the development of breeding lineages of plants and algae. In this study, it was developed a new variety of Pyropia yezoensis using gamma irradiation. It was applied a dose of 1 kGy and named the developed mutant Py1k. The blade with width of the mutant was narrower and the blade length was longer than those of the wild type. To further investigate the mutant, it was analyzed the nutrient composition and antioxidant activity. In comparison to those in the wild type, it was found a higher amino acid composition and marginally increased antioxidant activity in Py1k. Based on these results, it was suggests that our protocol can be utilized to develop Pyropia species with improved nutritional quality through gamma irradiation.

옥수수 생육에 미치는 저선량 감마선 조사효과 (Influence of Low Dose Gamma Radiation on the Growth of Maize(Zea mays L.) Varieties)

  • 김재성;이영근;박홍숙;백명화;김동희
    • 한국환경농학회지
    • /
    • 제19권4호
    • /
    • pp.328-331
    • /
    • 2000
  • 국내에서 재배중인 옥수수 재래종 (고성, 영월)품종의 종자에 저선량 ${\gamma}$선을 조사하여 초기생육과 수량에 미치는 영향을 온실과 포장실험으로 조사하였다. 저선량 방사선 조사가 옥수수 종자발아 및 초기생육에서 뚜렷한 촉진효과를 보였으나 품종별로 다소 차이가 있었으며 고성재래종은 2 Gy, 영월재래종은 12 Gy가 가장 효과적이었다. 포장생장과 수량에서도 저선량 조사에 의해 증가하는 경향을 보였는데 적정선량은 고성재래종은 8 Gy, 영월재래종은 $4{\sim}12$ Gy 범위로 나타났다.

  • PDF

폴리프로필렌 부직포에 아크릴산의 방사선 그라프트 반응에서 금속염의 효과 (Radiation-Induced Grafting of Acrylic Acid onto Polypropylene Fabric in the Presence of Metallic Salt)

  • 노영창;박종신;진준하
    • 공업화학
    • /
    • 제7권5호
    • /
    • pp.946-953
    • /
    • 1996
  • 동시조사법에 의한 아크릴산의 폴리프로필렌 부직포에 대한 그라프트 반응에서 조사량, 조사선량률, 금속염 및 용매가 그라프트 반응에 미치는 영향을 조사하였다. 같은 조사선량에서는 선량률이 낮을수록 높은 그라프트율을 나타냈다. 한편 조사선량률을 달리하여 일정 시간 동안 그라프트 반응시키면 조사선량률이 높을수록 그라프트율은 높았으며, 첨가한 금속염의 종류에 관계없이 그라프트 속도는 조사선량률의 0.74 차수에 비례하였다. 사용한 금속염 중에서 $FeSO_4{\cdot}7H_2O$가 가장 우수하였으며, 첨가제의 함량이 증가하면 할수록 그라프트율은 감소하였지만 적정농도이하에서는 그라프트용액이 고화되어 그라프트 반응시킬 수 없었다.

  • PDF

Longbone 검출기를 이용한 Scanogram의 유효성 평가 (Effectiveness Evaluation of Scanogram Using Longbone Detector)

  • 장수한;허지은
    • 대한방사선기술학회지:방사선기술과학
    • /
    • 제43권4호
    • /
    • pp.235-242
    • /
    • 2020
  • Scanogram is that combine several practical images into one image to observation. So it is an important consideration in many clinical situation such as iliac measurement, leg alignment measurement and Scoliosis. Currently, scanogram examinations are mainly conducted for children and elderly patients. In this study, in order to apply the longbone detector to children or elderly patients who are difficult to cooperate with, we compared the longbone detector from D equipment with the G equipment discovery 656 Puls equipment in reproducibility of images, distribution of irradiation dose, scattering dose, irradiation time and image acquisition time. D equipment took more than twice as much time as G equipment. The scattered dose generated about 50% more G equipment than D equipment. In the whole spine scanogram and the measurement length of the lower leg, D equipment was also measured longer than G equipment. However, both methods did not show much difference from the CT scanogram, so there was no problem in measurement. The height of the thyroid radiation dose of G equipment was produced more radiation than D equipment. However, the longbone detector deviated from the x-ray center line relative to the tube rotation method, and was measured lower by the directionality of the measuring instrument, so that the error could not be corrected. In the conclusion of study, using the longbone detector is excellent for applying to children or elderly patients to reduce scattering dose. However, using CR may be useful to normal patients. Because, the image quality may deteriorate due to an imbalance of dose difference in thickness depending on the body part. So, it is useful to using a compensation filter or tube rotation method when we take a whole spine scanogram.

방사선조사가 백서타액선조직에 미치는 영향에 관한 실험적 연구

  • 이의웅
    • 대한치과의사협회지
    • /
    • 제18권8호통권137호
    • /
    • pp.657-667
    • /
    • 1980
  • This study was undertaken to observe the salivary gland of the white rat when exposed to single and fractionated doses of Cobalt-60 irradiation. One hundred fifty white rats of the experiment were devided into control and 3 experimental groups. In experimental groups, group I receivcd 1200 rads everyweek untill 4800 rads reached, group II received 1500 rads and group III received 2000 rads with single dose. irradiation was carried out using a RAC-120 Cobalt-60 Teletherapy Unit with a dose rate 84.3 r/min, field size 4×5 cm measured at 80 from source. Rats were serially sacrificed at the following postirradiation time intervals: 1, 3, 5, 7, 10, 14, 21, 28, 35, and 42days. At sacrifice, the parotid and submandibular glands were dissected out in toto, and stained with: 1) hematoxylin and eosin; 2) periodic acid Shiff; 3) toludine blue.

  • PDF