• Nuclear Engineering and Technology
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• v.55 no.10
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• pp.3913-3923
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• 2023

Todays, medium energy resolution detectors are preferably used in radioisotope identification devices(RID) in nuclear and radioactive material categorization. However, there is still a need to develop or enhance « automated identifiers » for the useful RID algorithms. To decide whether any material is SNM or NORM, a key parameter is the better energy resolution of the detector. Although masking, shielding and gain shift/stabilization and other affecting parameters on site are also important for successful operations, the suitability of the RID algorithm is also a critical point to enhance the identification reliability while extracting the features from the spectral analysis. In this study, a RID algorithm based on Bayesian statistical method has been modified for medium energy resolution detectors and applied to the uranium gamma-ray spectra taken by a LaBr3:Ce detector. The present Bayesian RID algorithm covers up to 2000 keV energy range. It uses the peak centroids, the peak areas from the measured gamma-ray spectra. The extraction features are derived from the peak-based Bayesian classifiers to estimate a posterior probability for each isotope in the ANSI library. The program operations were tested under a MATLAB platform. The present peak based Bayesian RID algorithm was validated by using single isotopes(²⁴¹Am, ⁵⁷Co, ¹³⁷Cs, ⁵⁴Mn, ⁶⁰Co), and then applied to five standard nuclear materials(0.32-4.51% at.²³⁵U), as well as natural U- and Th-ores. The ID performance of the RID algorithm was quantified in terms of F-score for each isotope. The posterior probability is calculated to be 54.5-74.4% for ²³⁸U and 4.7-10.5% for ²³⁵U in EC-NRM171 uranium materials. For the case of the more complex gamma-ray spectra from CRMs, the total scoring (ST) method was preferred for its ID performance evaluation. It was shown that the present peak based Bayesian RID algorithm can be applied to identify ²³⁵U and ²³⁸U isotopes in LEU or natural U-Th samples if a medium energy resolution detector is was in the measurements.

• Microbiology and Biotechnology Letters
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• v.18 no.3
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• pp.244-250
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• 1990

A bacterium capable of hydrotyzing raw starch was isolated from soil, which was identified as a strain of Bacillue. The effects of culture conditions and medium compositions on the enzyme production were investigated. Among tested carbon sources, soluble starch and wheat starch were most effective for the production of the enzyme, and the level of concentration for the optimal enzyme production was 0.5%. For nitrogen sources, polypeptone was best for the enzyme production, with the level of 0.5%. The enzyme was maximally produced by cultivating the organism at medium of initial pH 6.5, and temperature of $35^{\circ}C$. The enzyme was partially purified by Sepharose CL-6B gel filtration and DEAESephacel ion-exchange chromatography. The optimal pH and temperature for the enzyme reaction were 6.5 and $70^{\circ}C$, respectively. The enzyme most stable at pH 8.0, and temperature up to $60^{\circ}C$. In kinetic studies, the k, values for corn, wheat, rice and potato starch were 1.7, 1.4,2.5 and 1.090, respectively.

• Korean Journal of Food Science and Technology
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• v.52 no.3
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• pp.212-219
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• 2020

The physicochemical characterstics of El Salvadoran Coffea arabica cv. Bourbon coffee extracts under various roasting conditions were investigated. Green beans were roasted under four different conditions (Light-medium, Medium, Moderately dark, and Very dark). The coffee extracts were prepared by using the espresso or drip methods. As the roasting degree increased, the coffee bean moisture content decreased and the ash content increased. The lightness and yellowness of the beans and coffee extracts decreased along with the increasing roasting degree. In the drip coffee, the reducing sugar content decreased and the pH value increased along with the increasing roasting degree. Both in the espresso and drip coffee, total organic acid and chlorogenic acid contents decreased, while the caffeine content increased along with the increasing roasting degree. Therefore, it is suggested that the roasting degree affects the physicochemical characteristics of coffee extracts.

• The Korean Journal of Mycology
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• v.25 no.4 s.83
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• pp.369-376
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• 1997

These researches were carried out for improvement of medium for mycelial growth of Hericium erinaceus isolate KU-1. It grew well at pH 4 and $25^{\circ}C$. Glucose and sucrose were favorable carbon sources for mycelial growth. As nitrogen sources, ammonium acetate and arginine enhanced mycelial growth. Optimum C/N ratio was 200. Based On the results, the following recipe is suggested for synthetic medium for the mycelial growth: glucose 18.02 g, arginine 2.613 g, ammonium acetate 2.313 g, $CaCl_2\;0.33\;g$, $KH_2PO_4\;8.5\;g$, $MgSO_4{\cdot}7H_2O\;2.0\;g$, $FeSO_4{\cdot}7H_2O\;0.02\;g$, $ZnSO_4{cdot}7H_2O\;0.02\;g$, $MnSO_4{\cdot}7H_2O\;0.02\;g$, water 1 liter. This medium was superior for the mycelial growth to other conventional media such as Yeast malt extract agar (YMA), Park medium, Potato dextrose agar (PDA), Malt extract agar, Czapek-dox agar, Macaya-lizano medium and Yeast extract agar. This new synthetic medium is designated as Ko medium.

• Tunnel and Underground Space
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• v.21 no.6
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• pp.471-479
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• 2011

The velocity horizontal response spectra using the observed ground motions from the recent 5 macro earthquakes, equal to or larger than 4.8 in magnitude, around Korean Peninsula were analysed and then were compared to the acceleration horizontal response spectra, seismic design response spectra (Reg Guide 1.60), applied to the domestic nuclear power plants, and finally the Korean Standard Design Response Spectrum for general structures and buildings. 102 velocity horizontal ground motions, including NS and EW components, were used for velocity horizontal response spectra and then normalized with respect to the peak velocity value of each ground motion. First, the results showed that velocity horizontal response spectra have larger values at the range of medium natural period, but acceleration horizontal response spectra have larger values at the range of short natural periods. Secondly, the results also showed that velocity horizontal response spectra exceed Reg. Guide 1.60 for longer natural periods bands less than 6-7 Hz. Finally, the results were also compared to the Korean Standard Response Spectrum for the 3 different soil types(SC, SD, and SE soil type) and showed that velocity horizontal response spectra revealed much higher values for the frequency bands below 1.5(SC), 2.0(SD), and 3.0(SE) seconds, respectively, than the Korean Standard Response Spectrum. The results suggest that the fact that acceleration, velocity, and displacement horizontal response spectra have larger values at the range of short, medium, and long natural periods, respectively, can be applied consistently to those form domestic ground motion, especially, the velocity ground motion. Information on response spectrum at such medium range periods can be very important since the domestic design of buildings and structures emphasizes recently medium and long natural periods than short one due to increased super high-rise buildings.

• Korean Journal of Animal Reproduction
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• v.26 no.1
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• pp.61-68
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• 2002

The present study was examined effects of aesculetin and $O_2$concentrations on in vitro development of Hanwoo (Korean Native Cattle) embryos derived from in-vitro matured and fertilized (IVM-lVF) oocytes. The oocytes were cultured for the first 40~44 h after in vitro fertilization, then embryos of 2 to 8 cell stages were cultured under the different culture conditions for another 6 days. In experiment 1, the higher rates of morulae and blastocysts were produced in 5% $O_2$, than in 20% $O_2$(P＜0.05). There was significantly (P＜0.05) higher in embryos cultured with 1 $\mu\textrm{g}$/$m\ell$ than with 0, 5 and 10 $\mu\textrm{g}$/$m\ell$ of aesculetin. In experiment 2, the proportions of embryo developed with blastocysts and morulae plus blastocysts in 5% $O_2$, again was significantly (P＜0.05) higher in 20% $O_2$, during the culture with aesculetin and/or taurine. In the 5 and 20% $O_2$atmosphere, the inclusion of 1 $\mu\textrm{g}$/$m\ell$ aesculetin or 2.5mM taurine increased significantly (P＜0.05) the percentages of blastocysts and morulae plus blastocysts. In experiment 3, in medium with aesculetin plus PDGF and taurine plus EGF than other treatment groups, significantly (P＜0.05) higher developmental rates were obtained. Number of blastomere in balstocyst stage were also higher in medium with that than without aesculetin. However, there were no significant differences in all culture conditions. In experiment 4, the proportions of embryo developed to the morulae and blastocyst stages were significantly (P＜0.05) higher rates in medium with natural and commercial aesculetin than in control medium. No significant differences, however, were observed in between natural (71%) and commercial (70.0%) aesculetin. Number of blastomere in blastocyst stage were also higher in medium with natural and commercial aesculetin than in control medium. However, there was no effect on the number of blastomeres by these treatment. These data indicate that preimplatation embryos are very sensitive to condition that can cause oxygen concentration and show that efficiency role of aesculetin for improving bovine embryo development in vitro.

• Journal of Bio-Environment Control
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• v.29 no.1
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• pp.1-8
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• 2020

The influence of growth regulators (NAA and BA) and sucrose concentrations (0, 3, 5, 7, 9%) on in vitro rapid-propagation of virus-free sweet potato [Ipomoea batatas (L.) Lam.] was investigated with single-node or shoot-tip culture of two cultivars ('Matnami' and 'Shinhwangmi'). The survival rate and growth of shoot-tip explant was also investigated under the presence or absence of light (blue and red LED = 7:3, 150±5 μmol·m^-2·s^-1 PPFD) during minimal-growth in vitro conservation at 15℃. Vine length, vine diameter, fresh weight and dry weight were enhanced without callusing of explant in the MS medium supplemented with 0.2-0.5 mg·L^-1 BA. The growth of single-node and shoot-tip explants were significantly enhanced with the increase of vine length, number of leaf, number of root, fresh weight, and dry weight in the solid medium containing 5% sucrose and 0.2 mg·L^-1 BA. Vine elongation of shoot-tip explants were highest in the liquid medium containing 3% sucrose than the solid medium. The survival rate of minimal-growth in vitro conservation was 100% in 5 months under the presence of light (LED, 150±5 μmol·m^-2·s^-1 PPFD) at 15℃, but the explants in dark condition died in 3 months. The light was absolutely necessary for the in vitro conservation under minimal-growth conditions of virus-free sweet potato plantlets at 15℃, and the high density of explants (10 plantlets per Petri Dish) was increased the efficiency of mass conservation.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.2
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• pp.172-178
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• 2002

The present study examined whether treatment of in vitro matured pig oocytes with calcium ionophore (A23187) could prevent polyspermic penetration in vitro. When oocytes cultured for maturation for 33, 36 or 44 h were subsequently treated with $50{\mu}M$ A23187 in medium with fetal calf serum (FCS) for 1, 2 and 3 h and then cultured for 12 h without spermatozoa, virtually no activation occurred. In the absence of FCS, however, 31-42, 45-49 and 56-64% of oocytes were activated, respectively. When oocytes treated with $50 {\mu}M$ A23187 in medium with FCS for 3 h were inseminated in vitro, the penetration rates (14-57%) were lower (p<0.01) with a higher (p<0.01) incidence (35-67%) of monospermy compared with untreated oocytes (69-80% penetration and 15-17% monospermy). However, sperm penetration was completely blocked in all oocytes treated with A23187 in the absence of FCS. When oocytes matured for 33 h were treated with different concentrations of A23187 for 3 h and inseminated in vitro, the penetration rate did not change but there was an increased incidence (p<0.05) of monospermy at $10-20{\mu}M$ and $2.5-5{\mu}M$ A23187 in the presence and absence of FCS, respectively, compared with at $0{\mu}M$ A23187. With these lower concentrations of A23187, treatment of oocytes for at least 60 and 30 min in the presence and absence of FCS, respectively, was required to increase the incidence of monospermy without reducing penetration rate. These results indicate that a high concentration ($50{\mu}M$) of A23187 in medium without FCS, but not in medium with FCS, stimulated in vitro matured pig oocytes to induce parthenogenetic activation and a complete block to sperm penetration in vitro. However, treatment of oocytes with lower concentrations of A23187 ( $10-20{\mu}M$ and $2.5-5{\mu}M$) both in the presence and absence of FCS maintained sperm penetration in vitro and increased the incidence of monospermy.

• Journal of Microbiology
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• v.37 no.2
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• pp.51-58
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• 1999

Using yeast, Saccharomyces cerevisiae, and the integrate vector system, we have isolated and characterized an autonomously replicating sequence (ARS) from Aspergillus nidulans. The DNA fragment, designated ANR1, is 5.0 kb in size and maintained free from the chromosome in S. cerevisiae. The YIplac211-ANR1 recombinant plasmid, which consists of sequences derived from the yeast integrative vector YIplac211 and 5.0 kb ANR1 fragment, showed a 104-fold enhancement in transformation efficiency over that found for YIplac211, and was easily recovered from the transformed yeast. Genetic analysis of transformants showed that YIplac21-ANR1 could be over 96% cured when cultured over 20 generations in complete medium and thus suggests that this sequence is mitotically unstable. In A. nidulans, recombinant plasmid PILJ16-4.5 which carries the 4.5 kb EcoRI fragment of ANR1 showed a 170-fold enhancement in transformation efficiency compared to that of the integrative vector PILJ16.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.5B no.2
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• pp.142-145
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• 2005

The life expectancy of a transformer largely depends on the temperature-rise it experiences. If the temperature-rise exceeds limits specified in the design standards, the aging of insulating materials is accelerated and the capability of the cooling medium is deteriorated. Consequently, applicable limits for the temperature-rise are essential in designing the transformer and the coolers, demanding the estimation of the transformer's thermal behavior. In order to analyze the temperature characteristics of the transformer, numerical analysis by way of the commercial CFD code has been carried out, and temperature-rise testing to verify computed results was performed. The results obtained in this study show that there is a good agreement between computed outcomes and experimental outcomes.