• Title, Summary, Keyword: Cobalt-60

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Sterilization Effect of Cobalt-60 to Irradiation for Bottled Natural Spring Water (Cobalt-60 동위원소에 의한 지하수의 멸균효과)

  • 최무웅
    • Proceedings of the Korea Water Resources Association Conference
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    • pp.506-512
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    • 1992
  • PET병에 넣어 시판되고 있는 일부 물중에서 일반세균과 대장균이 문제되고 있어 이러한 균을 멸균하기 위한 실험을 Cobalt-60과 X-ray를 이용하여 효과를 비교했다. 그 결과 Cobalt-60에 의해서 1.1KGY의 선량으로 물속의 모든 균은 멸균되었으나 X-ray에 의한 실험(56KVP 1mA 9초까지의 조사)에는 효과가 없었다. 앞으로 장기간 보관식품은 Cobalt-60에 의한 조사가 효과적이라고 생각되며 아울러 조사된 물은 인체에 하등의 영향을 주지 않는다.

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Effect of Aloe vera on the Blood Components of Cobalt-60 Gamma Irradiated Rats (Aloe vera가 Cobalt-60 gamma선 조사를 받은 쥐의 혈액성분에 미치는 영향)

  • Choi Min-chul
    • Journal of the korean veterinary medical association
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    • v.26 no.1
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    • pp.38-42
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    • 1990
  • The effect of Aloe vera administration(500mg/kg, P.O.) for 21 days on the total white blood cell, packed cell volume, hemoglobin, total protein, serum glutamic pyruvic transaminase and sorbitol dehydrogenase values in cobalt-60 gamma irradiated rats was s

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An Accidental over Exposure in Mednif Tele-Cobalt Machine in Nepal

  • chaurasia, P.P.;Srivastava, R.P.;Prasiko, G.;Neupane, B.P.
    • Proceedings of the Korean Society of Medical Physics Conference
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    • pp.97-99
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    • 2002
  • A radiation incident took place during treatment on MEDNIF Tele cobalt-60 therapy machine in B.P.KOIRALA MEMORIAL CANCER HOSPITAL in Bharatpur, Nepal. This Chinese made machine has activity of 6240 Curies of cobalt -60. This machine has fulfilled safety requirements. ICRP recommendations, safety rules are followed and practiced. The source was struck up during treatment and a technician was exposed to equivalent dose of 13.75 mSv. recorded by Personal film badge. Risks of workers are comparable to other safe industries. All exposures shall be kept as low as reasonably possible. The higher level of safety is achieved only when every one is dedicated to common goal. A lesson is learnt for future. Good practice is essential but not sufficient. A high demand for tele Cobalt therapy convinced management to replace Mednif machine with a new efficient Elite Tele Cobalt theratron Machine.

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The study on the separation characteristics of heavy metal ion by inorganic oxides and ion exchange resin (무기산화물 및 이온교환수지에 의한중금속 이온 분리특성 연구)

  • Dan, Cheol Ho;Kim, eong Ho;Yang, Hyun Soo
    • Clean Technology
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    • v.12 no.1
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    • pp.37-44
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    • 2006
  • The effectiveness of inorganic oxides (DT-30), anionic exchange resin (DT-60) and carbon absorbent (DT-80, DT-90) on the equilibrium and continuous separation characteristics and removal of cobalt, cesium and iodide ion in the waste water was investigated. As a result, DT-30, DT-80 or DT-90, and DT-60 showed excellent separation properties on the cesium, cobalt and iodide respectively. In the equilibrium experiment, the adsorption amount of cesium for DT-30 increased with temperature, but increasd largely with pH. In case of DT-80, adsorption of cobalt was depended on pH but was not influenced by temperature. In the continuous system by passing a heavy metal ion solution through the ion exchange tower, DT-30, DT-90 and DT-60 showed good separation characteristic for cesium, cobalt and iodide respectively. In this case, separation characterization of DT-30 on the cesium and of DT-60 on the iodide were better than that of DT-90 on the cobalt. From the experiment on the effect of impurities on the ion exchange characteristics, impurities such as surfactant and oil did not influence the efficiency of DT-90. In the mean while, ion separation capacity of DT-30 were decreased largely by impurities such as surfactant and oil. Also, surfactant had a strong influence on the effectiveness of DT-60. Accordingly, it turned out to be very important thing that impurities should be removed in the preprocessing stage.

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EFFECT OF COBALT-60 IRRADIATION ON THE DEVELOPING TOOTH GERM OF RAT (Cobalt-60이 발육치배조직에 미치는 영향에 관한 실험적 연구)

  • Lee Ki Sik
    • Journal of Korean Academy of Oral and Maxillofacial Radiology
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    • v.6 no.1
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    • pp.33-38
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    • 1976
  • The author observed the effects of the cobalt-60 irradiation on the amelogenesis and dentinogenesis of the albino rat fetuses by means of histological and histochemical methods. Females in oestrus were mated overnight and examined the next morning for evidence of copulation. The lower left abdomen of mothers were exposed to cobalt-60 irradiation on the 10th day of gestation, l00R 200R and 300R respectively. The fetuses were removed from the mothers on the 18th day of gestation. The employed histochemical methods were PAS reaction, colloidal iron reaction, aldehyde fuchsin stain, α-amino acid reaction, -SH radical reaction and methyl- green pyronin stain. The results were as follows; 1. The group irradiated by l00R made no histological differences in comparison with the control group. 2. Increasing the irradiation to 200R, abnormal dentin formation occured, and resulted in enamel hypoplasia and in atrophy and necrosis of odontoblasts. In dentinal papilla, the dilation and the degeneration of the blood vessels, excessive reticular atrophy and osteodentin were revealed. 3. With the more irradiation (200R-300R), the positive material of PAS, α-amino acid and aldehyde fuchsin tended to decrease in the ameloblast and the odontoblast. No significant changes appeared in DNA, the stainability of methylgreen pyronin.

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Modification of Survival and Blood-forming Stem Cells in Cobalt-60 Gamma Irradiated Mice by Aloe vera (Aloe vera투여가 Cobalt-60 감마선 조사를 받은 마우스의 생존율과 조혈간세포에 미치는 영향)

  • Choi Min-cheol;Sung Jai-Ki
    • Journal of Veterinary Clinics
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    • v.7 no.2
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    • pp.451-469
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    • 1990
  • The present study was carried out to investigate whether the aloe had a radioprotective effect in mice exposed to cobalt-60 gamma radiation or not. The survival ratio of mice for 30 days, hematopoiesis of blood-forming stem cells by spleen colony assay, chromosomal aberration frequency of bone marrow cells and histopathological findings of bone marrow were investigated. The survival ratios of aloe administered groups with concentration of 250, 500, 1,000 and 1,500mg for 3 days before irradiation and control group in cobalt-60 gamma irradiated mice(700rads whole body irradiation, dose rate of 50rads/min.) were 77.4, 79.3, 80.6, 90.0 and 53.1%, respectively. The survival ratios of pre-irradiation aloe administered groups were superior to those of post-irradiation aloe groups and control group. In spleen colony assay, Aloe vera administration before irradiation enhanced the recoveries of numbers of blood-forming stem cells of bone marrow of irradiated mice. There were decreased chromosomal aberrations of bone marrow cells at the first day after irradiation in aloe administered groups compared to that of control group. Histopathological findings in the bone marrow of irradiated mice were hypocellularity due to the depletion of myelocytes, abundant of fat vacuoles and these changes were weakened in aloe administered groups compared to that of control group.

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Study on the Reduction of Electron Contamination with A Cobalt-60 Gamma Ray (코발트-60 감마선의 전자 오염에 관한 연구)

  • Kim, Tae-Kyu;Chun, Ha-Chung;Lee, Myung-Za
    • Radiation Oncology Journal
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    • v.7 no.2
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    • pp.293-297
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    • 1989
  • Electron contamination due to the interaction between radiation beam and material was analyzed for the factors such as source-skin distance (SSD), field size, tray characteristics and position of filter, which can affect the surface dose in Cobalt teletherapy. Surface dose in open beam was more influenced by SSD with increasing field size. Relative surface charge (RSC) increased with the use of tray (solid, circular hole, slotted), compared with open beam, which is thought to be due to increased electron contamination of the tray. To reduce the surface dose, 0.4mm thick Lipowitz metal filter was used. Compared with open beam, RSC decreased by 8.8%, 11.3%, 13.3%, 16.6%, 19.3% and 21.7% for the field size of $5{\times}5$, $10{\times}10$, $15{\times}15$, $20{\times}20$, $25{\times}25$ and $30{\times}30cm^2$, respectively. On the contrary, use of Lipowitz metal filter increased RSC at 60cm or less SSD. Surface dose was effectively reduced with Lpowitz metal filter placed right below solid tray in Cobalt teletherapy.

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High Dose Rate Cobalt-60 After Loading Intracavitary Therapy of the Uterine Cervical Carcinoma in Srinagarind Hospital, Analysis of Residual Disease

  • Pesee, Montien;Krusun, Srichai;Padoongcharoen, Prawat
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.9
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    • pp.4835-4837
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    • 2012
  • Objectives: To evaluate residual disease in uterine cervical cancer patients treated with teletherapy using combined high dose rate Cobalt-60 brachytherapy. Materials and Methods: A retrospective study of uterine cervical cancer patients, FIGO stages IB-IVB (International Federation of Gynecologists and Obstetricians recommendations), treated by radiotherapy alone between April 1986 and December 1988 was conducted and the outcomes analysed. The patients were treated using teletherapy 50 Gy/25 fractions, five fractions per week to the whole pelvis together with HDR Cobalt -60 afterloading brachytherapy of 850 cGy/fraction, weekly to point A for 2 fractions. Results: The study covered 141 patients with uterine cervical cancer. The mean age was 50.0 years with a range of 30-78 years. The mean tumor size was 4.1 cm in diameter (range 1-8 cm). Mean follow - up time was 2.94 years (range 1 month-6.92 years). The overall incidence of residual locoregional disease was 3.5%. Residual disease, according to stage IIB, IIIB and IVA was present in 2.78%, 3.37% and 50.0%. It was noted that there was no evidence of residual disease in stage IB and IIA cases. Conclusion: Combined teletherapy along with high dose rate Cobalt -60 brachytherapy of 850 cGy/fraction, weekly to point A for 2 fractions resulted in overall 3.5% residual disease and a 96.5% complete response. The proposed recommendation for improving outcome is initiation of measurements for early detection of disease.

Effects of Cobalt-60 γ Irradiation on the Growth of Rabbits (Cobalt-60 gamma 선(線) 조사(照射)가 가토(家兎)의 성장(成長)에 미치는 영향(影響))

  • Sung, Jai Ki
    • Korean Journal of Veterinary Research
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    • v.12 no.1
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    • pp.1-5
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    • 1972
  • In oder to investigate the effects of cobalt-60 gamma ray irradiation on the body gains of rabbits aging approximately 50-day-old rabbits were subjected to single whole-body gamma irradiation externally. The results obtained were as follows: 1. There were significant differences of the body gains between control and treated groups except the 100 rads gamma-rays exposure group. 2. There were no differences in body gains between male and female rabbits. 3. Generally, the relation between gamma irradiated doses and the growth rates of rabbits were inversly proportional. 4. The $LD_{50}$ of the rabbits was 600 rads in case of single external whole-body gamma irradiation.

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Effect of a Copper, Selenium and Cobalt Soluble Glass Bolus Given to Grazing Yaks

  • Liu, Zongping
    • Asian-Australasian Journal of Animal Sciences
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    • v.20 no.9
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    • pp.1433-1437
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    • 2007
  • Two field trials were carried out to evaluate the performance of a soluble glass copper, cobalt and selenium bolus for maintaining adequate levels of the three trace elements in yaks. Forty yaks were used in trial 1 and 60 yaks were used in trial 2. In each trial two commercial soluble glass boluses were administered to half of the yaks. Blood samples were taken from the jugular vein at day 0, 30, 60, 90 in trial 1 and at day 0, 45, 75 and 105 in trial 2. The samples were analysed for copper status (serum caeruloplasmin activity and copper concentration), cobalt status (serum vitamin $B_{12}$ concentration and cobalt concentration), selenium status (erythrocyte glutathione peroxidase activity and selenium concentration) and serum zinc concentration. The erythrocyte glutathione peroxidase activities, serum caeruloplasmin activities and serum vitamin $B_{12}$ concentrations for trial 1 and 2 were all significantly increased for the bolused yaks (p<0.001 or p<0.01) on all sampling days. The bolused yaks had a significantly higher selenium and copper status in serum than the control yaks on all sampling days in trial 1 and 2 (p<0.05 or p<0.01). There were no significant differences in zinc and cobalt concentrations between the bolused yaks and the controls.