• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.7 no.1
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• pp.17-23
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• 2009

Dihexyloctanamide(DHOA) was used as an extractant or phase modifier with the diamide extractants in a solvent extraction process for a radioactive liquid waste treatment. The degradation compounds of the DHOA extractant, irradiated with $^{60}Co$ gamma ray, were octanoic acid and dihexylamine which are identified by a Fourier transform infrared(FT-IR) and gas chromatograph/mass spectrometer(GC/MS) analysis, and determined by the GC/MS with selected ion monitoring(SIM) mode. Retention behavior of octanoic acid, tridecane (internal standard) and dihexylamine in total ion chromatogram (TIC) were 8.65 min., 9.79 min., and 10.27 min., respectively. With increasing the absorbed dose of the $\gamma$-ray irradiated DHOA, the concentration of octanoic acid was decreased and that of dihexylamine was increased.

• The Journal of the Korea Contents Association
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• v.5 no.5
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• pp.133-139
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• 2005

The neutron capture cross section of $^{99}Tc$ has been measured relative to the $^{10}B(n,\gamma)$ standard cross section by the neutron time-of-flight(TOF) method in the energy range of 0.007 eV to 47 keV using a 46-MeV electron linear accelerator(linac) at the Research Reactor. Institute, Kyoto University(KURRI). In order to experimentally prove the result obtained, the supplementary cross section measurement has been made from 0.3 eV to 1 keV using the Kyoto University Lead stowing-down spectrometer (KULS) coupling to the linac. The relative measurement by the TOF method has been normalized to the reference value(20.01 b) at 0.0253 eV and the KULS measurement to that by the TOF method. The existing experimental data and the evaluated capture cross sections in ENDF/B-VI, JENDL-3.2, and JEF-2.2 have been compared with the current measurements by the linac TOF and the KULS experiments.

• Biomedical Science Letters
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• v.6 no.4
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• pp.261-268
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• 2000

Fibrinolytic enzyme (FE-2) was purified from the fruiting bodies of Tricholoma saponaceum using DEAE-Cellulose chromatography and Mono-S column chromatography, The enzyme has a molecular weight of 18.23 kDa and include Zn$^{2+}$ ion as found by ICP/MS. The N-terminal amino acid sequence of the enzyme was A-L-Y-V-G-X-S-P-X-Q-Q-S-L-L-V It has a pH optimum at pH 7.5, suggested that FE-2 was a neutral pretense. The activity of FE-2 was highly inhibited by EDTA and 1,10-phenanthroline, indicating that the enzyme is a metalloprotease. The activity of FE-2 was increased by $Mg^{2+}$, Zn$^{2+}$, Fe$^{2+}$, and Co$^{2+}$, but the enzyme activity was totally inhibited by Hg$^{2+}$. No inhibition was found with PMSF, E-64, pepstatin and 2-mercaptoethanol. The enzyme hydrolyzed both $A\alpha$ and B$\beta$ chains of human fibrinogen. The $\gamma$ chain was resistant to hydrolysis by FE-2.

• Analytical Science and Technology
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• v.21 no.5
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• pp.403-411
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• 2008

Dimethyldibutyltetradecylmalonamide (DMDBTDMA) extractant was used in a solvent extraction process for a radioactive liquid waste treatment. For the study of radiolysis phenomena, DMDBTDMA was synthesized and the degradation compounds (n-methylbutylamine, tetradecane, 1-tetradecanol) in the DMDBTDMA extractant, irradiated with $^{60}Co$ gamma ray, were identified and determined as radiolysis products by a Fourier transform infrared (FT-IR), gas chromatograph/mass spectrometer (GC/MS) analysis and GC/MS with selected ion monitoring (SIM) mode. Retention behavior of n-methylbutylamine, n-dodecane, tetradecane and 1-tetradecanol in the total ion chromatogram with the standard materials and n-dodecane as the internal standard (ISTD) were 2.35 min., 8.83 min., 10.68 min. and 12.75 min., respectively. In the case of tetradecane, there was a linear relationship between the concentration of the tetradecane and the absorbed dose of the ${\gamma}$-ray irradiated DMDBTDMA.

• Nuclear Engineering and Technology
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• v.56 no.9
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• pp.3558-3565
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• 2024

The linear attenuation coefficients (LAC) of four soils (Black cotton (S1), Sandy (S2), Clay (S3), and Sandy (S4)) samples were measured at photon energies released from radioisotopes Co⁵⁷ (122 keV), Ba¹³³ (356 keV), ²²Na (511 and 1275 keV), Cs¹³⁷ (662 keV), Mn⁵⁴ (840 keV), and Co⁶⁰ (1330 keV) using a gamma spectrometer includes a NaI (Tl) scintillation detector. The experimental measurements were confirmed utilizing the Monte Carlo N-particle transport code. The linear attenuation coefficient values enhanced from 0.256 cm^-1 to 0.296 cm^-1 (at E_γ of 122 keV), from 0.126 cm^-1 to 0.142 cm^-1 (at E_γ of 662 keV), and from 0.0938 cm^-1 to 0.105 cm^-1 (at E_γ of 1275 keV), raising the (Fe + Mn) concentration from 0.912 wt% to 11.214 wt%, as well as raising the soil samples density from 1.62 g/cm³ to 1.79 g/cm³. The study also shows an enhancement in the half value thickness, transmission factor, radiation protection efficiency and lead's equivalent thickness due to the enrichment of Fe + Mn concentrations within the studied soils. The results show that the Black cotton soil exhibits better shielding properties for γ-ray than the other soils.

• Journal of Environmental Science International
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• v.22 no.1
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• pp.83-89
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• 2013

Silicon carbide with aluminium oxide was used to remove the sulphur hexafluoride ($SF_6$) gas using microwave irradiation. The destruction and removal efficiencies (DREs) of $SF_6$ were studies as a function of various decomposition temperatures and microwave powers. The decomposition of $SF_6$ gas was analyzed using GC-TCD. XRD (X-ray powder diffraction) and XRF (X-ray Fluorescence Spectrometer) were used to characterize the properties of aluminum oxide. DREs of $SF_6$ were increased as the microwave powers were increased. Additive aluminium oxide on SiC increased the removal efficiencies and decreased the decomposition temperature. The XRD results show that the ${\gamma}-Al_2O_3$ was transformed to ${\alpha}-Al_2O_3$ during $SF_6$ decomposition by microwave irradiation. It was found that the best material to control $SF_6$ was SiC with $Al_2O_3$ 30 wt% in consideration of microwave energy consumption and $SF_6$ decomposition rate.

• Nuclear Engineering and Technology
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• v.52 no.6
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• pp.1282-1288
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• 2020

In the first study, the Radon emanation and radiological hazards associated with radionuclides in soil samples, collected from 9 various date palm farms located in 3 different districts in Saudi Arabia were determined through a high purity Germanium (HPGe) gamma-ray spectrometer. The estimated average values of Radon emanation coefficient and Radon mass exhalation rate for soil samples were 0.535 ± 0.016 and 50.063 ± 7.901 mBqkg^-1h^-1, respectively. The annual effective dose of radionuclides in all sampling locations was found to be lower than UNSCEAR's recommended level of 0.07 mSvy^-1 for soil in an outdoor environment. In the secondary study, gross α and gross β activities in soil and date palm pits samples were measured by a low background α/β counting system. Average values of gross α and gross β activities in soil and date palm pits samples were 5.761 ± 0.360 Bqkg^-1, 38.219 ± 8.619 Bqkg^-1 and 0.556 ± 0.142 Bqkg^-1, 24.266 ± 1.711 Bqkg^-1, respectively.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.2
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• pp.76.1-76.1
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• 2014

We present near-infrared spectroscopic and photometric observations of the nova V2468 Cyg taken from 2008 March 14 till 2008 November 11 following its outburst on 2008 March 7. The JHK spectra of the nova have been taken from the Mount Abu Infrared Observatory using the Near-Infrared Imager/Spectrometer. The early spectra are dominated by strong H I lines from the Brackett and Paschen series, Fe II, O I and C I lines, typical of Fe II type novae but after 46 days from outburst there is significant reduction in the strength of the C I lines and the spectra are dominated by He I lines. The FWHM of the Pa-beta and Br-gamma lines change from 2200-2300 km s-1 to 1700-1800 km s-1 after 12 days from outburst. Three additional small amplitude outbursts are seen near 110, 185 and 240 days in the V band light curve after the discovery. The upper limit for the ejecta mass for V2468 Cyg is estimated to be $5.2{\times}10-6Msun$.

• Journal of Ecology and Environment
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• v.32 no.1
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• pp.9-12
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• 2009

Artemisia capillaris and Artemisia iwayomogi are weeds used as medicinal plants in Korea under the name "Injin". I collected leaves of A. capillaris and A. iwayomogi, examined them for phytotoxic effects from volatile substances and determined the composition of monoterpenes in the leaves. The effects of volatile substances from each species on seed germination and radicle elongation in each of the two Artemisia species were assessed. The volatile substances of A. capillaris did not negatively affect the seed germination of A. capillaris, but they did inhibit radicle elongation. Rates of seed germination of A. iwayomogi decreased when the seeds were exposed to high concentration of A. capillaris volatile substances. The inhibition of seed germination and radicle elongation by volatile substances from both Artemisia species was stronger for A. iwayomogi than for A. capillaris. I identified the monoterpenoids from the leaves with a gas chromatograph-mass spectrometer (GC-MS). The main constituents of A. capillaris were acenaphthylene (37.91%), $\beta$-pinene (12.08%), 4-carene (10.61%) and $\gamma$-curcumene (9.92%), while those of A. iwayomogi were germacrene-$\delta$ (32.15%), borneol (21.24%), camphor (20.45%) and trans-caryophyllene (7.75%).

• Journal of Radiation Protection and Research
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• v.41 no.4
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• pp.333-338
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• 2016

Background: In case of radiation emergencies, internal exposure monitoring for the members of public will be required to confirm internal contamination of each individual. In-vivo monitoring technique using portable gamma spectrometer can be easily applied for internal exposure monitoring in the vicinity of the on-site area. Materials and Methods: In this study, minimum detectable doses (MDDs) for $^{134}Cs$, $^{137}Cs$, and $^{131}I$ were calculated adjusting minimum detectable activities (MDAs) from 50 to 1,000 Bq to find out the optimal in-vivo counting condition. DCAL software was used to derive retention fraction of Cs and I isotopes in the whole body and thyroid, respectively. A minimum detect-able level was determined to set committed effective dose of 0.1 mSv for emergency response. Results and Discussion: We found that MDDs at each MDA increased along with the elapsed time. 1,000 Bq for $^{134}Cs$ and $^{137}Cs$, and 100 Bq for $^{131}I$ were suggested as optimal MDAs to provide in-vivo monitoring service in case of radiation emergencies. Conclusion: In-vivo monitoring program for emergency response should be designed to achieve the optimal MDA suggested from the present work. We expect that a reduction of counting time compared with routine monitoring program can achieve the high throughput system in case of radiation emergencies.