• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.2
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• pp.175-182
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• 2017

We examined the effects of environmental factors on zoospore release and germling growth of the green tide alga Cladophora albida under various conditions of temperature${\times}$irradiance (zoospore release), temperature${\times}$irradiance${\times}$ nutrient (germling growth), and a single factor test of salinity. Zoospore release was maximized at $30^{\circ}C$ and $100{\mu}mol\;photons\;m^{-2}s^{-1}$ in the temperature irradiance experiment and at 34 psu in the salinity experiment. Maximum germling growth was observed at $25^{\circ}C$ with $100{\mu}mol\;photons\;m^{-2}s^{-1}$ and PES (Provasoli's Enriched Seawater) in the temperature irradiance nutrient experiment, and at 34 psu in the salinity experiment. Germlings grew faster at higher irradiances for a given temperature level, and also grew faster as salinity increased over the range of 5-34 psu. Overall, optimal environmental conditions for zoospore release were $30^{\circ}C$, $100{\mu}mol\;photons\;m^{-2}s^{-1}$ and 34 psu. Maximal germling growth occurred at $25^{\circ}C$, $100{\mu}mol\;photons\;m^{-2}s^{-1}$, PES, and 34 psu. C. albida blooms are most likely to occur under these optimal environmental conditions, as plentiful zoospore release and rapid germling growth lead to population growth.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.3
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• pp.276-283
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• 2011

The growth and tolerance for water temperature and salinity were compared among red sea bream Pagrus major (RSB) black sea bream Acanthopagrus schregeli (BSB) and their hybrid ($F_1$), female RSB ${\times}$ male BSB. The growth of the $F_1$ fish did not differ until 27 days after hatching (dAH), after which the most rapid growth was observed until approximately 300 dAH, followed by RSB and BSB. However, the RSB had out grown the $F_1$ fish by approximately 303 dAH. By 480 dAH, the RSB were largest, followed by the $F_1$ and BSB groups. The tolerances for high and low water temperature were significantly different for each species and growth stage. The largest tolerance spectrum was observed in the BSB group, and the tolerance spectrums gradually decreased with increasing final body weight. During the salinity tolerance trials, all of the species started to die following transfer into freshwater (0 psu). BSB showed the highest survival rate when kept in fresh water for an average of 29.9 hours, while the $F_1$ fish were more tolerant than the RSB fish. The fish were increasingly tolerant to fresh water and changes in water temperature as they grew, while the size of the temperature spectrum remained unchanged but shifted to a lower temperature range with growth. Our results demonstrate that $F_1$ performed well in terms of growth compared to parental fish, with higher temperature and salinity tolerances than RSB, and is thus suggested to be a suitable aquaculture species for Korea and northeast China.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.5
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• pp.657-664
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• 2016

The green macroalga Cladophora vadorum bloomed along the coast at Sangrok Beach, Buan, South Korea, in September 2015. To elucidate the cause of bloom, the effects of environmental factors on the vegetative growth of adult fragments were examined. Growth experiments were carried out under different combinations of temperatures and irradiances, and with a single factor of nutrients (nitrogen, phosphorus). The maximal growth of C. vadorum was reported under the combination of 25°C and 100 μmol photons m⁻²s⁻¹. The species grew under a wide range of N and P concentrations. The growth of C. vadorum peaked at 50 μM PO₄³⁻, 80 μM NH₄⁺, and 100 μM NO₃⁻. Adult fragments formed holdfasts and new branches within 3 days in culture and became adults, showing polarized growth patterns, in 2 weeks. This is the first report showing the development of numerous bladelets from a segment in Cladophora species. The present results indicate that Cladophora blooms appear under growth conditions that are favorable in terms of temperatures, irradiance, and nutrients via fragment growth patterns producing rapid holdfasts and many bladelets.

• Journal of the Korean Society for Heat Treatment
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• v.16 no.5
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• pp.260-266
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• 2003

In order to study the interfacial reaction between Nb thin sheet and Fe-C-(Si) alloy with different Chemical compositions, they were cast-bonded. The growth of carbide layer formed at the interface after isothermal heat treatment at 1173K, 1223K, 1273K and 1323K for various times was investigated. The carbide formed at the interface was NbC and the thickness of NbC layer was increased linearly in proportional to the heat treating time. Therefore, It was found that the growth of NbC layer was controlled by the interfacial reaction. The growth rate constant of NbC layer was slightly increased with increase of carbon content when the silicon content is similar in the cast irons. However, as silicon content increases with no great difference in carbon content, the growth of NbC layer was greatly retarded. The calculated activation energy for the growth of NbC layer was varied in the range of 447.4~549.3 kJ/moI with the compositions of cast irons.

• Journal of Korean Society on Water Environment
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• v.24 no.5
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• pp.550-555
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• 2008

This study was conducted to assess the growth characteristics of phytoplankton and to understand seasonal dynamics of phytoplankton in response to limiting nutrients in an agricultural reservoir from November 2002 to December 2003. Marked increase of chl.a concentration observed in July ($99.0{\mu}g/L$) and November ($109.7{\mu}g/L$) after heavy rainfall. TP concentration ranged $48.0{\sim}126.6{\mu}g/L$, and its the temporal variation was similar to that of chl.a concentration. Microcystis spp., dominant phytoplankton species were used for the growth kinetics experiment, except for the season when Aulacoseira spp. (March, April) and Aphanocapsa sp. (May) dominated. In the temperature range between $10{\sim}25^{\circ}C$, the rate of growth increase per $10^{\circ}C$ was almost two folds. The highest maximum growth rate (${\mu}_{max}=1.09day^{-1}$) of phytoplankton observed September, and ${\mu}_{max}$ was lowest ($0.34day^{-1}$) in March when Aulacoseira spp. dominated. The ${\mu}_{max}$ ($0.78{\pm}0.20day^{-1}$) was relatively high in the summer season when water temperature is above $20^{\circ}C$ and cyanobacteria dominated compared to the spring when diatoms dominated ($0.43{\pm}0.08day^{-1}$). The maximum growth rate ($0.55{\pm}0.12day^{-1}$) and the half saturation concentration ($K_s=0.73{\pm}0.15{\mu}M$) of cyanobacteria during winter season (November, December) was higher than those of diatoms. However, the ${\mu}_{max}$ and $K_s$ of cyanobacteria in December was similar to those of diatom, reflecting that diatom cell quota (Mean 48.4 pgP/cell) was greater than cyanobacteria (34.0 pgP/cell) during this time.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.11
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• pp.1137-1143
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• 2015

The stage II fretting fatigue crack growth and branching, i.e., the process of fretting fatigue crack growth starting in an inclined direction and then changing to the normal direction, is analyzed using the finite element method. The fretting fatigue experiment data of A7075-T6 are used in the analysis. The applicability of maximum tangential stress intensity factor, maximum tangential stress intensity factor range, and maximum crack growth rate as the crack growth direction criteria is examined. It is revealed that the stage II crack growth before and after the branching cannot be simulated with a single criterion, but can be done when different criteria are applied to the two stages of crack growth. Moreover, a method to determine the crack length at which the branching occurs is proposed.

• Nuclear Engineering and Technology
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• v.45 no.7
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• pp.827-838
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• 2013

Interaction layer growth between U-Mo alloy fuel particles and Al in a dispersion fuel is a concern due to the volume expansion and other unfavorable irradiation behavior of the interaction product. To reduce interaction layer (IL) growth, a small amount of Si is added to the Al. As a result, IL growth is affected by the Si content in the Al matrix. In order to predict IL growth during fabrication and irradiation, empirical models were developed. For IL growth prediction during fabrication and any follow-on heating process before irradiation, out-of-pile heating test data were used to develop kinetic correlations. Two out-of-pile correlations, one for the pure Al matrix and the other for the Al matrix with Si addition, respectively, were developed, which are Arrhenius equations that include temperature and time. For IL growth predictions during irradiation, the out-of-pile correlations were modified to include a fission-rate term to consider fission enhanced diffusion, and multiplication factors to incorporate the Si addition effect and the effect of the Mo content. The in-pile correlation is applicable for a pure Al matrix and an Al matrix with the Si content up to 8 wt%, for fuel temperatures up to $200^{\circ}C$, and for Mo content in the range of 6 - 10wt%. In order to cover these ranges, in-pile data were included in modeling from various tests, such as the US RERTR-4, -5, -6, -7 and -9 tests and Korea's KOMO-4 test, that were designed to systematically examine the effects of the fission rate, temperature, Si content in Al matrix, and Mo content in U-Mo particles. A model converting the IL thickness to the IL volume fraction in the meat was also developed.

• The Korea Journal of Herbology
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• v.36 no.4
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• pp.1-7
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• 2021

Objective : As more and more people are interested in appearance in modern society, the increasing number of hair loss population can have an important impact on psychological and social problems such as depression and inappropriate interpersonal symptoms. Therefore, much research is being done on treatments for alopecia using herbal extracts with relatively few side effects. This study was investigated about the effect of Achyranthis Radix (AR) extract with ethanol solvent on hair growth. Methods : We determined the promoting efficacy of AR-ethanol extract compared with minoxidil (MNXD) on the growth of human hair dermal papilla cells (HDPCs). Cell viability was measured by MTT assay and cell proliferation was confirmed by cell cycle analysis from flow cytometry in HDPCs. Also, we monitored the safe concentration range through MTT assay. And protein expression of hair growth-related genes (insulin-like growth factor 1 (IGF-1), Wnt3a, Protein kinase B (Akt), Extracellular signal-regulated kinase (Erk)) was monitored by western blot. Results : On cell cycle analysis, the G2/M phase was higher than that of the DW group in AR ethanol extract group at 0.05 and 0.1 mg/㎖. All protein expression levels of HDPCs were increased in AR ethanol extract groups and the MNXD group, compared to the DW group, respectively. Conclusion : As mentioned above, AR extract increased cell proliferation and the protein expression of IGF-1, Wnt3a, Akt, Erk in HDPCs. These results suggest that AR ethanol extract has promoted hair growth and it might be potential hair growth supplement.

• Tunnel and Underground Space
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• v.29 no.2
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• pp.124-134
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• 2019

Subcritical crack growth in rock material can occur under monotonic and cyclic loading. Subcritical crack growth plays an important role in evaluating the long-term stability of structures in rocks. This paper presents the results of studies conducted to determine subcritical crack growth parameters under monotonic and cyclic loading in rock-like material. The constant stress rate method was employed for monotonic loading. The subcritical crack growth parameter of n under cyclic loading was determined by the relation between the rate of crack growth per cycle and stress intensity factor range. The specimens contained pre-existing flaws with 45 and 60 degrees of inclination angle and flaws spacing and continuity were varied to arrange crack growth in shear or tensile manner. The results show that the parameter of n is almost constant regardless of the applied load conditions such as monotonic and cyclic or shear and tension.

• Journal of Chest Surgery
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• v.57 no.3
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• pp.231-239
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• 2024

Background: Although the modified Blalock-Taussig shunt remains the mainstay method of palliation for augmenting pulmonary blood flow in various congenital heart diseases, the shunt must be carefully designed to achieve the best outcomes. This study investigated the effect of shunt configuration on pulmonary artery growth and growth discrepancy. Methods: Twenty patients with successful modified Blalock-Taussig shunt takedown were analyzed. Pulmonary artery and shunt characteristics were obtained using computed tomography scans. Differences in the baseline and follow-up diameter ratios and growth in the ipsilateral and contralateral arteries were calculated. The angle between the shunt and pulmonary artery, as well as the distance from the main pulmonary artery bifurcation, were measured. Correlations between pulmonary arteries and shunt configurations were analyzed. Results: The median interval time between shunt placement and takedown was 154.5 days (interquartile range, 113.25-276.25 days). Follow-up values of the ipsilateral-to-contralateral pulmonary artery diameter ratio showed no significant correlation with the shunt angle (ρ=0.429, p=0.126) or distance (ρ=0.110, p=0.645). The shunt angle and distance from the main pulmonary bifurcation showed no significant correlation (ρ=-0.373, p=0.189). Pulmonary artery growth was negatively correlated with shunt angle (ipsilateral, ρ=-0.565 and p=0.035; contralateral, ρ=-0.578 and p=0.030), but not with distance (ipsilateral, ρ=-0.065 and p=0.786; contralateral, ρ=-0.130 and p=0.586). Conclusion: Shunt configuration had no significant effect on growth imbalance. The angle and distance of the shunt showed no significant correlation with each other. A more vertical shunt was associated with significant pulmonary artery growth. We suggest a more vertical graft design for improved pulmonary artery growth.