• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.05a
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• pp.785-787
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• 2016

In this study, we studied the gamma-radiation effect of fiber Bragg gratings on the high temperature annealing condition. The fiber Bragg gratings were exposed to gamma-radiation up to a dose of 30.8 kGy at the dose rate of 115 Gy/min. According to the experimental data and analysis results, the gratings that were stabilized at different temperatures have clearly shown that exposure to higher temperatures increases their radiation sensitivity.

• Journal of Yeungnam Medical Science
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• v.7 no.2
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• pp.109-114
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• 1990

The basic strategy of irradiation is to deliver a dose to the cancer that is high enough to make cancer cells incapable of reproduction, while keeping the doses to the various healthy tissues below tolerable levels. In order to improve local control and survival, as a boost therapy after external radiotherapy, high dose rate transcatheteric irradiation using remote control afterloading system(RALSTRON-20B) was used for twelve patients with head and neck cancers. Present results showed complete remission of cancer in 9 out of 12 patients without treatment related complications. Although this procedure is easy to operate, well trained skillful hand is essential for good results. Furthermore our experience suggested that meticulous treatment planning should be developed for better results.

• Journal of radiological science and technology
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• v.26 no.1
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• pp.39-44
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• 2003

The aim of this study is to evaluate a efficient w/v% barium suspension and w/v% sodium carboxy methyl cellulose (SCMC) for small bowel examination. Between november 2001 and june 2002, 370 patients were examined small bowel examination with oral administration of barium suspension mixed with SCMC. we classified into six groups including A(fine type 40% $BaSO_4$ mixed 0.5% SCMC and 600 ml 0.5% SCMC administration), B(fine type 30% $BaSO_4$ mixed 0.5% SCMC), C(fine type 20% $BaSO_4$ mixed 0.5% SCMC), D(fine type 25% $BaSO_4$ mixed 0.5% SCMC), E(D mixed coarse type 25% $BaSO_4$ mixed 0.5% SCMC), F(D mixed coarse type 25% $BaSO_4$ mixed 0.75% SCMC). We measured transparency rate of contrast media transit time, administration dose, viscosity and particle size. The transparency rate was higher then 80 kV and 90 kV in 100 kV in the same 20 mAs condition. Transit time was the fastest in A group(mean trans time 56 minutes) and the slowest in E group(mean 100 minutes), Administration dose was the smallest in A group(mean dose 541 ml and the most in E group(mean 1,100 ml), viscosity was the lowest in E(125.1 mpa/s) and the highest in A(375.5 mpa/s), and particle size was $1.0\;{\mu}m$ in A, B, C, and D group, $0.6\;{\mu}m,\;1.0\;{\mu}m,\;10.0\;{\mu}m$ in E, F group. In conclusion, we propose that the efficient condition for small examination is high voltage technique, high density $BaSO_4$, and 0.625% w/v SCMC.

• Journal of Information Technology Services
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• v.8 no.2
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• pp.147-156
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• 2009

As the result of the rapid development of IT technology, an on-line diagnostic system using the field bus communication network coupled with a smart sensor module will be widely used at the nuclear power plant in the near future. The smart sensor system is very useful for the prompt understanding of abnormal state of the key equipments installed in the nuclear power plant. In this paper, it is assumed that a smart sensor system based on the fieldbus communication network for the surveillance and diagnostics of safety-critical equipments will be installed in the harsh-environment of the nuclear power plant. It means that the key components of fieldbus communication system including microprocessor, FPGA, and ASIC devices, are to be installed in the RPV (reactor pressure vessel) and the RCS (reactor coolant system) area, which is the area of a high dose-rate gamma irradiation fields. Gamma radiation constraints for the DBA (design basis accident) qualification of the RTD sensor installed in the harsh environment of nuclear power plant, are typically on the order of 4 kGy/h. In order to use a field bus communication network as an ad-hoc diagnostics sensor network in the vicinity of the RCS pump area of the nuclear power plant, the robust survivability of IT-based micro-electronic components in such intense gamma-radiation fields therefore should be verified. An intelligent CCD camera system, which are composed of advanced micro-electronics devices based on IT technology, have been gamma irradiated at the dose rate of about 4.2kGy/h during an hour UP to a total dose of 4kGy. The degradation performance of the gamma irradiated CCD camera system is explained.

• Korean Journal of Plant Tissue Culture
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• v.27 no.2
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• pp.143-148
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• 2000

This study was carried out to know the optimum dose of gamma-ray for the induction of mutation in vitro and the characteristics of the mutants induced by gamma-ray in persimmon (Diospyros kaki Thunb.). The LD50 (50% lethal dose) for in vitro shoots of the cultivar, Nishimurawase was between 1 krad and 2 krad and about 1 krad for the cultivar, Ichikikeijiro. As the dose of gamma-ray increased, the length of shoots decreased and necrosis of buds increased. For the cultivar, Nishmurawase, 37.5∼58.3% shoots rooted and the rooting rate and the number of roots per shoot was low in high gamma-ray. The irradiated young plants which were grown in the growth cabinet for 6 weeks were shorter in shoot length and had more branches than non-irradiated plants. The survival rate of irradiated plants grown in the green house for 3 months was 33%, while 77% for control plants.

• The Journal of Korean Society for Radiation Therapy
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• v.4 no.1
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• pp.71-77
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• 1990

The present study was undertaken to investigate effects of ionizing radiation on DNA synthesis and chromosomal abnormality in cultured submandibular gland(SG) cells. SG cells from C57BL/6N Crj mice were cultured in Dulbecco's modified Eagle's medium (DME) supplemented with $10\%$ fetal bovine serum, antibiotics and fungizone. The cultured SG cells were irradiated with graded doses of gamma ray ($^{60}Co$) at a dose rate of 58.4rad/min. The effect of irradiation of $^{60}Co$ on DNA synthesis in cultured cells was evaluated by measuring the incorporation of 3H-TdR. Using conventional chromosome techniques and Giemsa staining methods, chromosomal abnormalities in cultured SG cells, induced by irradiation of $^{60}Co$ werw examined. Cytological observations were carried out by a light microscope with high resolving power. The results obtained were as follows : 1. DNA synthesis of SG cells was quantitatively dependent on a radiation dose compare to control. 2. A polyploids and few chromosome-type break, such as single and double breaks, deltions and triradial figures were more predominantly in irradiated SG cells than in control. This increase of chromosomal abnormality was in the proposition to the irradiation doses.

• Nuclear Engineering and Technology
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• v.56 no.1
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• pp.207-215
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• 2024

This study focuses on measuring the levels of naturally occurring radioactivity in the soil of Swabi, Khyber Pakhtunkhwa, Pakistan, as well as the associated health hazard. Thirty (30) soil samples were collected from various locations and analyzed for ²²⁶Ra, ²³²Th, and ⁴⁰K radioactivity levels using a High Purity Germanium detector (HPGe) gamma-ray spectrometer with a photo-peak efficiency of approximately 52.3%. The average values obtained for these radionuclides are 35.6 ± 5.7 Bqkg^-1, 47 ± 12.5 Bqkg^-1, and 877 ± 153 Bqkg^-1, respectively. The level of ²³²Th is slightly higher and ⁴⁰K is 2.2 times higher than the internationally recommended limit of 30 Bqkg^-1 and 400 Bqkg^-1, respectively. Various parameters were calculated based on the results obtained, including Radium Equivalent (Ra_eq), External Hazard (H_ex), Absorbed Dose Rate (D), Annual Gonadal Equivalent Dose (AGDE), Annual Effective Dose Rate, and Excess Lifetime Cancer Risk (ELCR), which are 170.3 ± 24 Bqkg^-1, 0.46 ± 0.06 Bqkg^-1, 81.4 ± 2.04 nGy h^-1, 582 ± 78.08 µSvy^-1, 99.8 ± 13.5 µSv Gy^-1, and 0.349 ± 0.04, respectively. These values are below the limits recommended by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) in 2002. This study highlights the potential radiation threats associated with natural radioactivity levels in the soil of Swabi and provides valuable information for public health and safety.

• Journal of the Korean Society of Radiology
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• v.14 no.2
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• pp.77-83
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• 2020

This study investigated the radiation protection of therapeutic radiologists. Based on the change in X-ray energy and MU value, the space dose rate in the treatment room after the irradiation was measured. 6MV, 10MV and 15MV photon beams were exposed to radiation inside the treatment room based on 300MU, 600MU and 1000MU using a linear accelerator. And repeated 10 times under the same conditions. As a result of the experiment, 0.1555 μSv/h for 6MV 300MU, 0.157 μSv /h for 300sec, 0.152 μSv/h, 0.156 μSv/h for 600MU, and 0.157 μSv/h 0.152 μSv/h for 1000MU. 300MU of 10MV was 0.49 μSv/h, 0.309 μSv/h, and 0.69 μSv/h, 0.416 μSv/h for 600MU, respectively, and 1000MU was 0.977 μSv/h and 0.478 μSv/h, respectively. The 300MU of 15MV was 3.02 μSv/h, 1.2 μSv/h, 5.459 μSv/h at 600MU, 7.34 μSv/h at 1.836 μSv/h 1000MU, and 2.709 μSv/h. The average spatial dose rate of 6MV was not significantly different from the natural spatial dose rate in the treatment room. High spatial dose rates were measured at 10 MV and 15 MV and were attenuated over time. Therefore, entering the treatment room after a certain period of time (more than 60 seconds) is considered to be effective to prevent the exposure dose of radiation workers.

• The Korean Journal of Pharmacology
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• v.22 no.1 s.38
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• pp.34-44
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• 1986

In our previous studies, we had clarified many pharmacological effects of majarine: the bacteriostatic effect in vitro; the potentiation of hypnotic action of alcohol; hypotensive effect in rats and hypothermic effect in mice. This study was undertaken to search for a new antihypertensive drug. Red crystalline was obtained from majarine (which was extracted from Berberis koreana Palibin) by chemical methods. And this crystalline was identified as $C_{19}H＿{16}NO＿4$ contained one hydroxy group instead of methoxy group of majarine in isoquinoline ring and named 'Majarol' (5,6-Dihydro-9-hydroxy, 10-methoxybenzo-[g]-1,3-benzodioxolo [5,6-a] quinolizinium). We examined the effects of majarol on blood pressure and heart rate in urethane ancsthetized rats and the rate and amplitude of contraction of isolated frog heart. Several drugs: atropine sulfate, diphenhydramine chloride, hexamethonium bromide, phentolamine, epinephrine, propranolol and isoproterenol were used to clarify the mechanism of the hypotensive action of majarol. The results of experimints were as follows; 1. In low dose (0.5-2mg/kg, i.v.), majarol showed a typical transient hypotensive effect and slight decrease in heart rate. In high dose (5-10 mg/kg, i.v.), majarol showed a typical transient and a subsequent prolonged hypotensive effect and a significant prolonged decrease in heart rate was followed. 2. The hypotensive effects of majarol was not abolished by the pretreatments with atropine sulfate, hexamethonium bromide and diphenhydramine. The pretreatment with phentolamine inhibited significantly the hypotensive effects of majarol and the pretreatment wtih majarol blocked markedly the hypertensive effect of epinephrine. The positive chronotropic effect of isoproterenol was not blocked by the pretreatment with majarol. 3. In low dose, majarol increased the amplitude and decreased rate of contraction, but in high dose, majarol inhibited the amplitude and rate of contraction of isolated frog heart.

• KSBB Journal
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• v.26 no.3
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• pp.206-210
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• 2011

The growth effect of Nannochloropsis oculata (N.oculata), unicellular microalgae, by alginate was investigated. Alginate was depolymerized with sulfuric acid ($H_2SO_4$) and heat ($121^{\circ}C$), simultaneously. Addition of 0.75% alginate oligomer depolymerized with 0.2 N $H_2SO_4$ showed the maximum yield and the growth rate of N. oculata. Chlorophyll content and reducing sugar was increased by alginate oligomer in a dose-dependent manner. Alginate oligomer promoted the growth of N. oculata, whereas the original alginate polysaccharides had no significant effect. Laminaria japonica (L. japonica) extract containing high level of alginate was also increased growth rate and chlorophyll content. $CO_2$ supply addition to L. japonica extract showed no change the growth rate, although addition to alginate oligomer showed prominently increased. N. oculata could use more saccharides in presence of $CO_2$ according to reducing sugar determination. From these results, it is useful to establish optimal condition for high cell density cultivation of N. oculata.