• The Korean Journal of Mycology
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• v.51 no.3
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• pp.251-257
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• 2023

We isolated fungi from the rhizosphere of Fallopia sachalinensis in Dokdo islands. Morphological and molecular characters, based on the internal transcribed spacer (ITS), and partial large subunit (LSU) or partial beta-tubulin genes, were used to identify the isolated fungi. The results revealed the fungi isolated from the Fallopia rhizosphere to be Penicillium striatisporum and Gongronella sichuanensis. Given that these species have never previously been recorded in Korea, we have described the morphological and molecular characteristics of these fungi in this study.

• Korean Journal of Agricultural Science
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• v.10 no.2
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• pp.206-211
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• 1983

This study was carried out to compare the feed utilization between pelleted and all-mash diet of similar composition by growing chickens. Day-old broilers (Hubbard) and egg-type chickens(Hy-line) of commercial strain were employed in this experiment. The results obtained were summarized as follows. 1. The chickens fed pelleted diets were heavier than those of birds fed all-mash diets. The Hubbard broilers and Hy-line chickens fed pelleted diets weighed 2,702g and 812g respectively, at 9 weeks of age. In comparison, the Hubbard broilers and Hy-line chickens fed all-mash diets weighed 2,571g and 777g respectively, at 9 weeks of age. 2. The pellet-fed chickens consumed more feeds than birds fed all-mash diets in both types of strain. Feed efficiencies (gain/feed) of Hubbard and Hy-line chickens were 0.38 and 0.26 in pellet feeding groups, and 0.36 and 0.25 in all-mash feeding groups, respectively. The Hy-line chickens fed pelleted diets drank more water than birds fed all-mash diets. 3. Pellet feeding groups produced more dry matter excreta as compared with all-mash feeding groups, reflecting the pattern of feed consumption by these chickens. Nitrogen retention ratio of the Hubbard and Hy-line chickens were 57-67% and 65-73%, respectively. Chickens fed pelleted diets showed 1-4% higher nitrogen retention than chickens fed all-mash diets. 4. The ME/GE ratio of the Hubbard and the Hy-line at 8 weeks of age were 73.4-74.3% and 82.8-83.8%, respectively. Pellet feeding groups showed 1% higher ME/GE ratio than all-mash feeding groups. 5. The dietary productive energy calculated from respiratory quotient was $94.1-102.6kca/kg^{\frac{3}{4}}$ BW/day in pellet feeding groups. The ratios of PE/GE were 41.3-48.9% in pellet feeding groups and 39.0-45.8% in all-mash feeding groups. 6. It appears that pelleting the all-mash diet increases feed consumption and body weight gain of growing chickens. Feed efficiency and energy utilization were also improved by pelleting process. More research work should be done to establish the relationship clearly between feed pelleting and heat increments.

• Journal of Energy Engineering
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• v.21 no.4
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• pp.419-426
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• 2012

A transient, three-dimensional, two-phase flow analysis code, CUPID, has been developed in KAERI. In this work, we performed a preliminary analysis using the CUPID code to investigate the thermal-hydraulic behavior of the moderator in the Calandria vessel of a CANDU reactor. At first, we validated the CUPID code using the three experiments that were performed at Stern Laboratories Inc. To avoid the complexity to generate computational mesh around the Calandria tube bundles, a porous media approach was applied for the region. The pressure drop in the porous media zone was modeled by an empirical correlation. The results of the calculations showed that the CUPID code can predict the mixed flow pattern of forced and natural convection inside the Calandria vessel very well. Thereafter, the analysis was extended to a two-phase flow condition. Also, the local maximum temperature in the Calandria vessel was plotted as a function of the injection flow rate, which may be utilized to predict the local subcooling margin.

• Environmental and Resource Economics Review
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• v.17 no.3
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• pp.167-199
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• 2008

There are many successful cases in power interconnection among European and South American countries. However, that is not the case in Northeast Asian countries. Even though there will be a considerable benefit in power interconnection in Northeast Asian countries, there will be some difficulties due to various interest relationship and constraints among countries in Northeast Asia. GTMax(Generation and Transmission Maximization) Program is a very useful tool to analyze competitive electricity market and power interconnection developed by Argonne National Laboratory under the Department of Energy in the USA. This study tried to verify applicability and usefulness by GTMax model to domestic electric power system and power transfer from Russia Far East by power interconnection. When the power by importing from Russia is 2,000MW(around 2% of domestic installed capacity in 2017), there is no impact on domestic electricity market because of small power transfer. The power by importing should be large enough for achieving greater cost reduction by power interconnection. Besides, it would be better to supply power to Kyung-In region directly in reducing overall cost when the power by importing from Russia are sold at low price. In the case of interconnecting Young-Dong region, if it is not possible to upgrade transmission line with power transfer capabilities between Young-Dong and Kyung-In region, then the power by importing from Russia can replace the power produced in Jung-Bu region and the relative benefit of importing power can be reduced.

• The Journal of Engineering Geology
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• v.16 no.3 s.49
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• pp.235-244
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• 2006

Granite cores were sampled within Korea Atomic Energy Research Institute and cyclic loadings up to 1550 cycles were applied. Microcrack development in samples due to cyclic loading was estimated using Acoustic Emission(AE) method. AE showed two different types depending on numbers of cycle. Type 1 appeared at low cycles and had low energy and diverse frequencies, while type 2 appeared at high cycles and had high energy and uniform frequency. AE property of type 1 indicates voids and pre-existing microcracks in samples may close or propagate up to certain length. Microcracks may be sheared or closed during loading and are recovered from shear or opened during unloading when AE of type 2 were measured. P wave velocities and Felicity ratios were measured at 50, 150, 350, 750, 1550 cycles. P wave velocities were almost the same regardless of number of cycles applied. However, Felicity ratios were much lower than 0.9, indicating that microcracks were developed within samples. This result indicates that Felicity ratio is a better tool than P wave velocity to estimate the damage of rock.

• Solar Energy
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• v.15 no.3
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• pp.105-117
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• 1995

Heat transfer coefficients on a single spiral coil tube in the furan foundry sand fluidized bed have been investigated. Heat transfer coefficients(ho) to an immersed single spiral coil tube were measured in the bed. The bed diameter was 0.21 m. The following quantities were varied: (l)bed temperature, (2)mean particle diameter, (3) fluidization rate, (4)the ratio of heated coil tube pitch to diameter(p/Do), and (5)the ratio of heated coil tube pitch to mean particle diameter(p/dp). In addition, the experimental values of maximum Nusselts number were compared with the values of maximum Nusselts number predicted by the existing correlations. The values of heat transfer coefficient increase with the increase in bed temperature and fluidization rate, but decrease with increase in particle diameter. An empirical formulus of maximum Nusselts number which is applicable in the furan foundry sand fluidization bed is as follows: $$Nu_{max}=1.01\;Re^{0.48}Prg^{0.4}(p/dp)^{0.28}(p/Do)^{0.05}$$.

• Food Science and Industry
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• v.53 no.4
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• pp.390-396
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• 2020

We investigated the anti-obesity effect of Gelidium elegans extract (GE) on 3T3-L1 preadipocytes and a high-fat-diet (HFD)-induced mouse model. The results of the present study demonstrated that GE prevents weight gain induced by a high-fat diet (HFD) by modulating the adenosine monophosphate-activated protein kinase (AMPK)-PR domain-containing 16 (PRDM16)-uncoupling protein-1 (UCP-1) pathway in a mice model. Moreover, in vitro results show that GE suppressed adipocyte differentiation by modulating adipogenic regulators, stimulated lipolysis by activating ATGL, and inhibited adipogenesis by downregulating various enzymes associated with triglyceride synthesis. GE was also found to upregulate AMPK phosphorylation as well as the expression of UCP1 and PRDM16 proteins, leading to measurable changes in the beige-like phenotype differentiation of 3T3-L1 cells. Taken together, these findings suggest the role of GE as a functional food ingredient extracted from Gelidium elegans to increase energy expenditure and anti-obesity efficacy.

• Phonetics and Speech Sciences
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• v.14 no.2
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• pp.55-65
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• 2022

This study aimed to compare acoustic measurements by the high, middle, and low laryngeal heights of male musical theater students. Furthermore, the correlation between the relative height of the larynx and the acoustic measurements was examined, along with the predictability of the relative height (vertical position) of the larynx from acoustic measurements. The participants included five male students majoring in musical theater singing, and acoustic analysis was performed by having them produce the /a/ vowel 10 times each at the laryngeal positions of high, middle, and low. The relative vertical positions of the laryngeal prominence in each position were measured based on the resting position. Results indicated that the relative position of the larynx varied significantly according to laryngeal height, such that as the larynx descended, the first three formant frequencies decreased while the spectral energy at the same frequencies increased. Formant frequencies showed a weak to moderate positive correlation with the relative height of the larynx, while the spectral energy showed a moderate negative correlation. The relative height of the larynx was predicted by eight acoustic measures (adjusted R² = .829). In conclusion, the predictability of the relative height of the larynx was partially confirmed in a non-invasive manner.

• Clean Technology
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• v.29 no.3
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• pp.217-226
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• 2023

The amount of hydrogen adsorbed in arrays of single walled carbon nanotubes (SWNTs) was studied as a function of nanotube diameter and distance between the nearest-neighbor nanotubes on square arrangements using a grand canonical Monte Carlo simulation. The influence of the geometry of a triangle array with the same diameters and distances was also studied. Hydrogen-carbon and hydrogen-hydrogen interactions were modeled with Lennard-Jones potentials for short range interactions and electrostatic interactions were added for hydrogen-hydrogen pairs to consider quantum contributions at low temperatures. At 194.5 K, Type I isotherms for large-diameter SWNTs and Type IV isotherms without hysteresis between adsorption and desorption processes for wider tube separations were observed. At 200 bars, the gravimetric hydrogen storage capacity of the SWNTs was reached or exceeded the US Department of Energy (DOE) target, but the volumetric capacity was about 70% of the DOE target. At 77 K, a two-step adsorption was observed, corresponding to a monolayer formation step followed by a condensation step. Hydrogen was adsorbed first to the inner surface of the nanotubes, then to the outer surface, intratubular space and the interstitial channels between the nanotube bundles. The simulation indicated that SWNTs of various diameters and distances in a wide range of configurations exceeded the DOE gravimetric and volumetric targets at under 1 bar.

• Journal of agriculture & life science
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• v.50 no.4
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• pp.113-125
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• 2016

This study was conducted to investigate the effect of low feeding level of concentrate after sexual maturity(14 month old) on the growing and breeding performances in Hanwoo cows. Eighteen cows(average body wt. 251kg) were alloted to two groups by completely randomized design, and fed a commercial formula feed by 0.8%(T1) and 1.2%(T2) of body weight for 30 months of total experimental period(feeding trial of 20 months, breeding trial of 10 months). When the results of this experiment compared to the Korean feeding standard for Hanwoo(2012), the reason of low growing performance in T1 was induced from low protein intake rather than energy. The change of body size by feeding levels was significantly appeared at chest width and body length, particularly chest width of cows in T1 was rather reduced by 3.7% in the final than the initial measurement. Ovarian size of T1 was only 63% of T2, and pregnancy rate(33.3% : 77.8%) and birth wight of calf(22.5kg : 29.5kg) were also seriously repressed by low intake of dietary protein after sexual maturity in Hanwoo cow. It was appeared that the growing and breeding performances of Hanwoo cows were more affected by the level of dietary protein rather than energy in the feeding after sexual maturity.