• Journal of Yeungnam Medical Science
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• v.5 no.1
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• pp.147-151
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• 1988

Esophageal cancers are highly malignant neoplasms. Prognosis of esophageal cancer treated by external irradiation alone is rather poor because of local recurrence and distant metastasis. Recently intracavitary irradiation has been used as a boost therapy after external irradation to optain better local control. One case of esophageal cancer has been treated by high dose rate remote-controlled afterloading unit as boost therapy after external irradiation. The result was excellent in short term follow up esophagogram but esophageal bleeding and esophagotracheal fistula were noted in further follow up examination after inappropriate posttreatment management including insufficient chemotherapy due to poor general condition. We reviewed possible causes of esophageal bleeding and esophagotracheal fistula after external irradiation and high dose rate ICR.

• Journal of the Korean Society of Tobacco Science
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• v.15 no.2
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• pp.167-173
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• 1993

Pirimiphos - methyl was fogged in a tobacco warehouse to determine the proper dose rate, Small wire cages, containing adults and larvae of cigarette beetle (Lasiodema senicorne F.) were put at different altitude in the warehouse of which the holding capacity was about 250m3. At recommended dose rate, 0.4ml/m3(25% ai), it brought about 100% mortality of adults and 98.8% -100% mortality of larvae. When the dose rate was reduced to about half the recommended one, 97.6 and 96.4% mortality could still be obtained against adults and larvae, respectively. The number of the beetles monitored by sex - pheromone trap was greatly reduced after the fogging in the warehouses at 4 geographic places in Korea. When the warehouses were ventilated for one hour immediately after the fogging done for 48 hours, workers could not detected any opposing smell in the warehouses. And panel members responded positively that there was no negative effect on the taste of the cigarettes made of the fogged tobacco. Although the residue of the chemical was detected from the cigarettes in 4 of 5 cases, the residue was 1.1-1.3$\mu\textrm{g}$/20 cigarettes except for one case from which 3.3$\mu\textrm{g}$/20 cigarettes residue was detected. The relatively low residue is about l/450-1/150 of the WHO/FAO tolerant level.

• Korean Journal of Clinical Pharmacy
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• v.9 no.2
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• pp.92-96
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• 1999

The pharmacokinetics of carbamazepine(100 mg/kg, oral) in the folic acid-induced renal failure rabbits was studied. Renal failure was induced by the i.v. injection of folic acid (50, 100, and 200 mg/kg). At folic acid dose of 100 and 200 mg/kg, the serum creatinine concentration (Scr) and blood urea nitrogen (BUN) increased significantly compared with control rabbits. Plasma concentrations and area under the plasma level-time curve (AUC) of carbamazepine increased significantly at folic acid dose of 100 and 200 mg/kg. The elimination rate constant (Kel) of carbamazepine decreased significantly, and half-life $(t_{1/2})$ of carbamazepine increased significantly at folic acid dose of 100 and 200 mg/kg. The serum creatinine concentration (Scr) correlated well with AUC and elimination rate constant (Kel) of carbamazepine, as well as BUN with AUC and elimination rate constant (Kel) of carbamazepine. These results suggest that adjustment of the dosage regimen of carbamazepine is desirable, and serum creatinine concentration (Scr) as well as BUN can be used for adjusting the dosage regimen of carbamazepine in renal failure.

• Nuclear Engineering and Technology
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• v.53 no.11
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• pp.3704-3710
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• 2021

The characteristics of the external radiation on the surface of the casks for spent nuclear fuel (SNF) storage by dry method are investigated for the case when the spatial distribution of SNF in the basket changes due to the destruction of the fuel rod claddings. The surface areas are determined, where the changes in fluxes of neutrons, produced by ²⁴⁴Cm actinide, and γ-quanta, produced by long-lived isotopes, are maximum in the result of the decrease in the height of the SNF area. Concrete (VSC-24) and metal (SC-21) casks are considered as examples. The procedure of periodic measurement of the dose rate of neutrons or γ-quanta at the specified points of the cask surface is proposed for identifying the fuel rod cladding destruction. Under normal operation, the decrease in the dose rate produced by neutrons as the function of SNF storage duration is determined by the half-life of ²⁴⁴Cm, and for γ-quanta - by the half-lives of long-lived SNF isotopes. Consequently, a stepwise change in the dose rate of neutrons or γ-quanta, detected by the measurements, as compared to the previous one, would indicate the destruction of the fuel rod claddings.

• Nuclear Engineering and Technology
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• v.51 no.6
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• pp.1626-1632
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• 2019

Monitoring of environmental radioactivity is essential for ensuring the radiological safety of residents who live near nuclear power plants. Ulsan, South Korea, is surrounded by 16 nuclear power plants, the highest density in the country. In addition, the city contains facilities for conducting radiological nondestructive testing and using radioisotopes for medical purposes. It makes the confirmation of radiological safety particularly necessary. In this study, sampling points were selected based on regional characteristics, and surface water samples were pretreated and analyzed for gross beta and gamma radiation levels. In addition, the distribution of the city's gamma dose rate was determined using a mobile monitoring system and distribution visualization program. The results showed that there is no effect on the gross beta and gamma nuclides of artificial radionuclides, and the gamma dose rate of the entire region did not exceed the environmental radiation level in South Korea overall, confirming the radiological safety of the city.

• Nuclear Engineering and Technology
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• v.53 no.5
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• pp.1483-1490
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• 2021

Many studies are undertaken into nuclear power plants (NPPs) in preparation for accidents exceeding design standards. In this paper, we analyze the applicability of various wireless communication technologies as accident countermeasures in different NPP environments. In particular, a commercial wireless communication module (WCM) is investigated by measuring leakage current and packet error rate (PER), which vary depending on the intensity of incident radiation on the module, by testing at a Co-60 gamma-ray irradiation facility. The experimental results show that the WCMs continued to operate after total doses of 940 and 1097 Gy, with PERs of 3.6% and 0.8%, when exposed to irradiation dose rates of 185 and 486 Gy/h, respectively. In short, the lower irradiation dose rate decreased the performance of WCMs more than the higher dose rate. In experiments comparing the two communication protocols of request/response and one-way, the WCMs survived up to 997 and 1177 Gy, with PERs of 2% and 0%, respectively. Since the request/response protocol uses both the transmitter and the receiver, while the one-way protocol uses only the transmitter, then the electronic system on the side of the receiver is more vulnerable to radiation effects. From our experiments, the tested module is expected to be used for design-based accidents (DBAs) of "Category A" type, and has confirmed the possibility of using wireless communication systems in NPPs.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.22 no.3
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• pp.377-385
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• 2024

The concrete silo dry storage system, which has been in operation at the Wolsong NPP site since 1992, consists of a concrete structure, a steel liner plate in the inner space, and a fuel basket. The silo system's concrete structure must maintain structural integrity as well as adequate radiation shielding performance against the high radioactivity of spent nuclear fuel stored inside the storage system. The concrete structure is directly exposed to the external climatic environment in the storage facility and can be expected to deteriorate over time owing to the heat of spent nuclear fuel, as well as particularly cracks in the concrete structure. These cracks may reduce the radiation shielding performance of the concrete structure, potentially exceeding the silo system's allowable radiation dose rate limits. For specimens with the same composition and physical properties as silo's concrete structures, cracks were forcibly generated and then irradiated to measure the change in radiation dose rate to examine the effect of cracks in concrete structures on radiation shielding performance, and in the current state, the silo system maintains radiation shielding performance.

• Horticultural Science & Technology
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• v.34 no.1
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• pp.122-133
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• 2016

While ion beams are widely used in plant breeding, little is known about the sensitivity of Lavandula angustifolia (lavender) to ionizing radiation. To compare the biological effects of different types of ionizing radiation on the germination and survival rates of lavender, we exposed lavender seeds to gamma rays, 3 MeV electron beams, and 1.89 MeV proton ion beams. We observed that the seed germination rate decreased with increasing dosages of all three types of ionizing radiation. The malformation rate of lavender seedlings exposed to electron beams and gamma rays increased with increasing radiation dosage. By contrast, the effect of the accelerated proton beams on the malformation rate was negatively correlated with the dosage used. The survival rate of lavender seedlings exposed to the three types of ionizing radiation decreased in a dose-dependent manner. In addition, the survival rate of seedlings irradiated with proton and electron beams decreased more slowly than did that of seedlings irradiated with gamma rays. The half-lethal dose of gamma rays, electron beams, and proton beams was determined to be 48.1 Gy, 134.3 Gy, and 277.8 Gy, respectively, and the most suitable proton-ion energy for lavender seeds in terms of penetration depth was determined to be 5 MeV. These findings provide valuable information for the breeding of lavender by radiation mutation.

• Journal of radiological science and technology
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• v.25 no.1
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• pp.73-76
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• 2002

In order to evaluate the exposure to the radiologic technologists from patients who had been administrated with radiopharmaceuticals, we measured the spatial dose rates at 5 cm, 50 cm, and 100 cm from skin surface of patients using an proportional digital surveymeter, both 5 min after injection and right before the studies. In results, the exposure to the technologists in each procedure was small, compared nth the dose limits of the medical workers. However, the dose-response relationships in cancer and hereditary effects, referred to as the stochastic effects, have been assumed linear and no threshold models ; therefore, the exposure should be minimized. For this purpose, the measurements of spatial dose rate distributions were thought to be useful.

• ETRI Journal
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• v.27 no.4
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• pp.449-452
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• 2005

The electrical characteristics of solid state devices such as the bipolar junction transistor (BJT), metal-oxide semiconductor field-effect transistor (MOSFET), and other active devices are altered by impinging photon radiation and temperature in the space environment. In this paper, the threshold voltage, the breakdown voltage, and the on-resistance for two kinds of MOSFETs (200 V and 100 V of $V_{DSS}$) are tested for ${\gamma}-irradiation$ and compared with the electrical specifications under the pre- and post-irradiation low dose rates of 4.97 and 9.55 rad/s as well as at a maximum total dose of 30 krad. In our experiment, the ${\gamma}-radiation$ facility using a low dose, available at Korea Atomic Energy Research Institute (KAERI), has been applied on two commercially available International Rectifier (IR) products, IRFP250 and IRF540.