• The Korean Journal of Mycology
• /
• v.19 no.3
• /
• pp.214-219
• /
• 1991

Adenosine-5'-triphosphatase$(F_1-ATPase)$ in the Lentinus edodes was fractionated by ammonium aulfate 30% saturation and purified by Sephadex G-200 gel filtration in three times. Three kinds of protein fractions of $F_1-ATPase$ were isolated from this mushroom, and fraction I and ll showed its activity for the substrate, adenosine-5'-triphosphate. Its optimum pH and temperature were found to be pH 7.6 and $58^{\circ}C$, and its thermal stability was stabled for 30 min. at $20-30^{\circ}C$. The Km value of this enzyme was 1.81 mM.

• Journal of the Korean Chemical Society
• /
• v.26 no.1
• /
• pp.24-30
• /
• 1982

Contact-only (COM) and dipolar-only (DOM) mixtures of the lanthanide shift reagents were prepared based on the Fi and Gi values deduced using individual Ln$(fod)_3$ (Ln = Pr, Nd, Eu, and Yb) and 4-picoline. The $F_i$ and $G_i$ values obtained directly by COM 1 and by DOM 1, which were appropriate mixture of Pr$(fod)_3$ and Eu$(fod)_3$, agreed well with those values obtained by experiments using individual Ln$(fod)_3$ shift reagents. Ei and Gi values obtained directly by COM 2 and by DOM 2, which were mixtures of Nd$(fod)_3$ and Yb$(fod)_3$, deviated from the expected values. The error was traced to the behavior of the ytterbium complexes.

• The Korean Journal of Mycology
• /
• v.23 no.1 s.72
• /
• pp.14-27
• /
• 1995

For the searching of antibiotics in the mushroom, we studied on the screening of antiyeast and antifungal components. The powder of fruiting body of each mushroom was extracted with petroleum ether, 80% ethanol, and distilled water in that order, respectively. The antifungal activity of each extract from 32 different mushrooms were tested. The petroleum ether or ethanol extracts from fruiting bodies of Boletus auripes, Leccinum extremiorientale, Gomphus floccosus, Phaeolus schweinitzii, Pycnoporus cinnabarinus and Marasmius maximus showed antiyeast activities. The ethanol extract of Gyrophora esculenta showed an antiyeast activity against Cryptococcus neoformans, and its minimal inhibitory concentration (MIC) was $600\;{\mu}g/ml$. The petroleum ether or ethanol extracts from fruiting bodies of Amanita citrina, Leccinum extremiorientale, Gomphus floccosus, Phaeolus schweinitzii, Pycnoporus cinnabarinus, Marasmius maximus and Gyrophora esculenta showed antifungal activities. The ethanol extract of Gomphus floccoscus showed an antifungal activity against Microsporum gypseum, and its MIC was $1,000\;{\mu}g/ml$. The ethanol extract of Gyrophora esculenta showed antifungal activities against Trichophyton mentagrophytes, Microsporum gypseum and Pyricularia oryzae, and theirs MIC were $300\;{\mu}g/ml,\;600\;{\mu}g/ml\;and\;600\;{\mu}g/ml$, respectively. The petroleum ether extract of Gyrophrora esculenta also showed an antifungal activity against Microsporum gypseum, and its MIC was $300\;{\mu}g/ml$.

• Journal of Veterinary Clinics
• /
• v.29 no.2
• /
• pp.119-123
• /
• 2012

The present study evaluated the effects of different anesthesia techniques on oxidative stress in beagle dogs. Ten dogs were randomly assigned to either total intramuscular anesthesia with medetomidine-tiletamine/zolazepam (MTZ) combination (group T, 40 ${\mu}g/kg$ medetomidine and 2 mg/kg tiletamine/zolazepam) or volatile anesthesia with isoflurane (group I, 2% isoflurane and 100% oxygen). Heart rate, respiratory rate, and rectal temperature for vital signs and the concentration of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) for oxidative stress were measured. SOD activity decreased significantly from baseline anesthesia in both groups ($p$ < 0.05). CAT and GPx activities were also decreased significantly after anesthesia between both groups ($p$ < 0.05). CAT activity decreased significantly from baseline after anesthesia in both groups, but activities of group I were significantly higher compared with group T after anesthesia ($p$ < 0.05). GPx activity in group T decreased significantly from baseline after anesthesia, but activities of group I were significantly higher compare with that of group T 1 hour after the conclusion of anesthesia ($p$ < 0.05). In conclusion, general anesthesia seems to induce oxidative stress, and volatile anesthesia with isoflurane attenuates oxidative injuries in beagle dogs.

• Korean Journal of Agricultural Science
• /
• v.27 no.1
• /
• pp.48-53
• /
• 2000

The various errors existing in a weight measurement system in most automatic egg sorting system available in Korean poultry farms have caused a large amount of economic losses to the egg producers. The object of this study was an importance of egg measurement system by changing both the number and the arrangements of load cells to reduce measuring errors. The results obtained were summarized as follow : 1. Four arrangements of load cells were selected as follows : layout I : Conventional one load cell method layout II : One load cell located as egg moving direction layout III : Two load cells located facing each other layout IV : Two load cells located as parallel with egg moving direction 2. The results of egg weight measurement according to four arrangements (Layout I, II, III, IV) showed that the average errors were 1.1218g, 0.5953g, 0.7786g, 0.2793g respectively. This indicated that the Layout IV (measuring by 2 load cells located parallel with the egg moving direction) caused the lowest average error and the best in precision. 3. The average vibration of axis X, y, Z were resulted as $5.1937{\times}10^{-3}G$, $9.3604{\times}10^{-3}G$, and $16.8657{\times}10^{-3}G$ respectively when sorting large sized egg. This indicated that the vibration of axis-Z was relatively higher than those of axis-X, and axis-Y.

• Korean Journal of Ichthyology
• /
• v.34 no.2
• /
• pp.102-112
• /
• 2022

This study investigated dietary habits and intra- and inter-specific food resource partitioning of co-occurring walleye pollock (Gadus chalcogrammus) and Pacific cod (G. macrocephalus) from the waters off the north-eastern coast of South Korea using stomach contents and stable isotopes (δ¹³C and δ¹⁵N) analyses. Both species are mesopelagic carnivores that consumed mainly benthopelagic crustaceans, but teleosts were also abundant in the diet of Pacific cod. Non-metric multidimensional scaling (nMDS) ordination and permutational multivariate analysis of variance (PERMANOVA) of dietary data revealed significant intra- and inter-specific dietary differences, i.e., food resource partitioning. Nitrogen stable isotope values (δ¹⁵N) were similar between walleye pollock and Pacific cod, but carbon stable isotope values (δ¹³C) were significant different, suggesting different trophic positioning. Canonical analysis of principal coordinate (CAP) ordination plot further demonstrated that differences in the type and range of prey ingested by the two species contributed such an inter-specific difference in the diet compositions. Ontogenetic changes in diet compositions were evident. As walleye pollock, they preyed more upon carid shrimps and cephalopods, but no such trend was observed in the diets of Pacific cod. While stable isotope values indicated that large-sized specimens of both species were significantly enriched in ¹⁵N relative to smaller conspecifics thus supporting these data. Consequently, in this study, both methodologies, i.e., stomach contents and stable isotope analyses, provided evidence of inter- and/or intra-specific dietary segregations and trophic niche partitioning between co-occurring walleye pollock and Pacific cod off eastern Korean waters.

• Korean Journal of Materials Research
• /
• v.5 no.1
• /
• pp.22-35
• /
• 1995

In this study, crystal structures and magnetic properties of as-ast, annealed and rapidly solidified Mn-A1-M( M=Cu, Fe) alloys have been investigated. In $Mn_{0.56}Al_{0.44}$ alloys, the largest fraction of $\tau$ phase and values of magnetic properties was obtained in Mnl, i6Alo or alloy. And this alloy was used as the basic composition. In $Mn_{0.56-X}M_{X}Al_{0.44}$ alloys, when annealed, $\tau$- and $\beta$-Mn phase appeared at x< 0.08, $\tau$- and $\kappa$ phase at 0.10 $\leq x \leq$ 0.12 and $\kappa$- phase only at 0.15 $\leq x \leq$0.20 . When rapidly solidified, specimens showed similar phases as when annealed except that $\varepsilon$ phase appeared at x=0.04. In Mnu FexAlo 44 alloys, asyast specimens showed $\tau$-, $\beta$-Mn and $\gamma_2$- phase at x<0.08 and K and $\beta$-Mn phase at x>0.10. When rapidly solidified, Mn-Fe-Al specimens showed $\varepsilon$-, $\gamma_2$- and small amount of $\tau$- and $\kappa$ phase at x<0.08 and $\kappa$- phase only at 0.$\leq x \leq$0.20. All the alloys investigated were ferromagnetic. The Curie temperature of annealed specimens and rapidly solidified of Mno 5sAlu 44 alloy were -650K and -644K. Spontaneous magnetization( UII of annealed and rapidly solidified specimens were 40-45 (emu/g) and 50-52(emu/g), respectively. Remanent (M,) to saturation magnetization( Ms) ratio was -0.7. M, of rapidly solidified specimen was about 48(emu/g). Magnetic properties of $Mn_{0.56}Al_{0.44}$ alloys were found to be determined by the relative fraction of ferromagnetic r- and K- phase. When M= Cu and x=0.15, maximum as($\sigma_{0.0}$) was obtained by about 64.3 emu/g), and when M=Fe and x=0.15, 66.4( emu/g). The Curie temperature decreased as x increased.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.10 no.5
• /
• pp.663-671
• /
• 1999

The linearity of the GaAs FET power amplifier(PA) is greatly influenced by source and load impedance for the FETs. The third order intermodulation products, IM3, from the GaAs FET PA are investigated in relation with source and load impedance. From heuristic as well as analytic point of view, e.g., Volterra series analysis, is employed to analyze the effects of nonlinear circuit elements, gate-source capacitance, $C_{gs}$, and drain-source current, $I_{ds}$. The sweet spots where soure and load impedance produce the least intermodulation products are calculated and compared with the load and source pull data with good agreements. It also shows that source impedance has a greater effect on the intermodulation products than the load impedcnce.

• The Journal of Society for e-Business Studies
• /
• v.17 no.2
• /
• pp.63-72
• /
• 2012

The Korean telecommunications market has been expanding swiftly, these days, to be saturated. In this environment, the upcoming mobile telecommunication market, where 4G service was introduced this year, is becoming more substitutive and competitive. Thus, the demand forecasting of 4G service is very difficult, while it is critical to market success. This paper adopts a multi-generation diffusion model to capture the diffusion and substitution patterns for two successive generation of technological services, i.e., 3G and 4G mobile telecommunications services. The three parameters, i.e., the coefficient of innovation, the coefficient of imitation, and the coefficient of market potential, used in the multi-generation diffusion model based on Norton and Bass[11] are obtained by inference from similar substitutive relations between older and newer telecommunication services to 3G and 4G services. The simulation results show that the Bass type multi-generation model can be successfully applied to the demand forecasting of newly introduced 4G mobile telecommunication service.

• Journal of the Korean earth science society
• /
• v.37 no.1
• /
• pp.11-20
• /
• 2016

Diatoms were studied from the trench sediments around Bangudae petroglyphs in order to better understand the depositional environment before and after the construction of Sayeon dam in Ulsan. There were no diatoms produced from the sediments before the dam construction while the diatoms were produced from the sediments (depth of trench 228 cm) after the construction of the dam. Seventy-five species of diatoms of 27 genera were identified in the trench sediments. The number of diatom valves per gram of dry sediment ranged from $0.2-5.8{\times}10^5g^{-1}$. Four diatom assemblage zones were identified according to the frequency of critical taxa as follows: assemblage zone I, from 228 to 150 cm; assemblage zone II, from 150 to 122 cm; assemblage zone III, from 122 to 62 cm; and assemblage zone IV, from 62 to 0 cm. In addition, based on the environmental indicator species, an analysis was carried out to measure eutrophication, acidity and $Cl^-$ value. Results of the eutrophication and $Cl^-$ values were as follows. Based on the lower 74 cm horizons, the degree of eutrophication middle-high to $Cl^-$ values were lower, upper horizons appeared to eutrophication in the low, and $Cl^-$ values were high. Acidification from low horizons of 122 cm showed a neutral-alkaline degree whereas it exhibited acid in the upper part. In particular, regarding nutrients (TP and TN), the index taxa showed a higher TP value at 175 cm while higher TN value at 62 cm.