• 태양에너지
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• 제11권3호
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• pp.31-36
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• 1991

태양열 온수기로부터 획득한 $50{\sim}60^{\circ}C$의 온수를 이용하여 수온이 낮은 3, 4, 10, 11월은 물론 한 겨울철에도 미꾸리의 최적 성장온도를 유지시켰던 바 다음과 같은 결과를 얻었다. 가. 전장 $4{\sim}5cm$, 체중 $1{\sim}2g$정도의 미꾸리의 최적 성장수온은 $18{\sim}20^{\circ}C$이고 $5{\sim}7cm,\;2{\sim}3g$인 것은 $20{\sim}22^{\circ}C$이고 $7{\sim}9cm,\;4{\sim}6g$인 것은 $22{\sim}24^{\circ}C$의 수온임을 알아냈다. 나. $1{\sim}3g$의 개체는 서서히 성장하나 $4{\sim}8g$의 것은 성장이 빠르고 총개체수의 무게 총량은 1개월간에 약 $30{\sim}50g$ 증가하였다.

• 한국해양생명과학회지
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• 제2권2호
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• pp.39-48
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• 2017

생존율은 염분과 관계없이 8℃, 10℃일 때는 98.7~100%였으나, 4℃일 때는 생존율이 25~55%로 나타났다. 혈림프액 내 SOD와 glutathione 농도와 같은 스트레스 지표는 모든 염분구에서 4℃, 6℃일 때 높게 나타났다. THC, hemocyte population, apoptotic cell및 necrotic cell의 비율은 염분 별로는 26 psu구에서 가장 높게 나타났고, 4~6℃일 때 다른 실험구에 비해 유의하게 높았다. 이러한 결과들은 26 psu의 염분과 6℃ 이하의 수온에서는 참전복의 스트레스 반응이 증가하였으나, 30, 34 psu의 염분과 8, 10℃의 수온에서는 대조구와 차이가 없어, 참전복의 수송을 위한 적정 수온 및 염분 조건은 8~10℃, 30~34 psu인 것으로 나타난다.

• 한국발생생물학회지:발생과생식
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• 제20권3호
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• pp.255-266
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• 2016

The optimum concentrations of clove oil as an anesthetic for olive flounder (Paralichthys olivaceus) and the stress response of the fish to clove oil anesthesia were determined over a range of water temperatures, and investigated in a simulated transport experiment using analysis of various water and physiological parameters. While the time for induction of anesthesia decreased significantly as both the concentration of clove oil and water temperature increased, the recovery time increased significantly (P<0.05). The plasma cortisol concentration in fish at each temperature increased significantly up to 12 h following exposure (P<0.05), then decreased to 48 h (P<0.05). The DO dissolved oxygen concentrations, pH values, and the fish respiratory frequencies decreased over 6 h following exposure to clove oil in all experimental groups (P<0.05), whereas the $NH_4{^+}$ and $CO_2$ concentrations in all experimental groups increased up to 6 h (P<0.05). The pH values and DO concentrations increased with increasing clove oil concentration (P<0.05) in the 6 h following exposure, and the $CO_2$ and $NH_4{^+}$ concentrations and the respiratory frequencies decreased with increasing clove oil concentration (P<0.05). The results of this experiment suggest that clove oil reduced the metabolic activity of olive flounder, thus reducing $NH_4{^+}$ excretion and $O_2$ consumption. In conclusion, clove oil appears to be a cost-effective and efficient anesthetic that is safe for use and non-toxic to the fish and users. Its use provides the potential for improved transportation of olive flounder.

• 한국생활과학회지
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• 제24권6호
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• pp.859-871
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• 2015

The purpose of this study is to examine the influence of the pigment characteristic and changes in dying conditions on the dying properties by extracting Chelidonium majus var. asiaticum using distilled water and ethanol as solvents. Changes in dying conditions include variations in dye concentrations, dyeing temperatures and time on dye uptake, and K/S Value was compared according to these changes. Additionally, color changes were observed through mordant. Ultraviolet-visible spectrum was used to investigate the pigment characteristic, and as a result, tannin was identified in distilled-water-extract, whereas berberine and chlorophyll were identified in ethanol-extract. In FT-IR analysis, tannin in distilled-water-extract was verified as hydrolyzable tannin. For ethanol extract, chlorophyll was verified through absorption band of C-H, which is aliphatic spectrum around $2920cm^{-1}$ and $2850cm^{-1}$. From GC/MS analysis, oil components as well as terpine compounds were detected in ethanol-extract, and this, in turn, brings expectation regarding functionality. When dying in silk, dye uptake increased as concentration of the extract increased, and the optimum dyeing temperature and time were $40^{\circ}C$ and 60 minutes respectively. Dyed fabrics' colors were all basically Y-series colors, and adjustment in brightness and revelation of khaki color were also available depending on the type of the mordant. Color fastness, except for washing fastness, was good in silk dyed with distilled-water-extract. Thus, it can be concluded that by selecting the right extracting method and by doing proper dyeing and mordant according to the needs, these dyed fabrics can be used as eco-friendly, functional clothing material.

• Asian-Australasian Journal of Animal Sciences
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• 제27권9호
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• pp.1319-1327
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• 2014

Two feeding trials were conducted to determine the optimum feeding frequency in growing Korean rockfish, (Sebastes schlegeli) reared at the temperatures of $15^{\circ}C$ and $19^{\circ}C$. Fish averaging $92.2{\pm}0.7$ g (mean${\pm}$standard deviation [SD]) at $15.0{\pm}0.5^{\circ}C$ and $100.2{\pm}0.4g$ ($mean{\pm}SD$) at $19.0{\pm}0.5^{\circ}C$ water temperature were randomly distributed into each of 15 indoor tanks containing 250-L sea water from a semi-recirculation system. A total of five feeding frequency groups were set up in three replicates as follows: one meal in a day at 08:00 hour, two meals a day at 08:00 and 17:00 hours, three meals a day at 08:00, 14:00, and 20:00 hours, four meals a day at 08:00, 12:00, 16:00, and 20:00 hours, and one meal every 2 days at 08:00 hour. Fish were fed at the rate of 1.2% body weight (BW)/d at $15^{\circ}C$ and 1.5% BW/d at $19^{\circ}C$. At the end of 8 wks of feeding trial weight gain and specific growth rate were significantly higher at the fish fed groups of one meal a day and two meals a day at $15^{\circ}C$ and fish fed groups of 1 meal every 2 days at $19^{\circ}C$ were significantly lower than those of all other fish fed groups. Glutamic oxaloacetic transaminase and glutamic pyruvic transaminase of fish fed group at 1 meal every 2 days was significantly higher than those of all other fish fed groups in both experiments. Weight gain, specific growth rate and condition factor were gradually decreased as the feeding frequency increased. The results indicate that growing Korean rockfish 92 and 100 g perform better at $15^{\circ}C$ than $19^{\circ}C$ water temperature. As we expected, current results have indicated that a feeding frequency of 1 meal a day is optimal for the improvement of weight gain in growing Korean rockfish grown from 92 g to 133 g at $15^{\circ}C$ and 100 g to 132 g at $19^{\circ}C$ water temperature.

• Bulletin of the Korean Chemical Society
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• 제26권11호
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• pp.1776-1782
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• 2005

ZnSe/ZnS, UV-blue luminescent core shell quantum dots, were synthesized via a thermal decomposition reaction of organometallic zinc and solvent coordinated Selenium (TOPSe) in a hot solvent mixture. The synthetic conditions of the core (ZnSe) and the shell (ZnS) were independently studied at various reaction temperature conditions. The obtained colloidal nanocrystals at corresponding temperatures were characterized for their optical properties by UV-vis, room temperature solution photoluminescence (PL) spectroscopy, and further obtained powders were characterized by XRD, TEM, and EDXS analyses. The synthetic temperature condition to obtain the best PL emission intensity for the ZnSe core was 300 ${^{\circ}C}$, and for the optimum shell capping, the temperature was 135 ${^{\circ}C}$. At this temperature, solution PL spectrum showed a narrow emission peak at 427 nm with a PL efficiency of 15%. In addition, the measured particle sizes for the ZnSe/ZnS nanocomposite via TEM were in the range of 5 to 12 nm. Furthermore, we have synthesized water-soluble ZnSe/ZnS nanoparticles by capping the ZnSe/ZnS hydrophobic surface with mercaptoacetate (MAA) molecules. For the obtained aqueous colloidal solution, the UV-vis spectrum showed an absorption peak at 250 nm, and the solution PL emission spectrum showed a peak at 425 nm, which is similar to that for hydrophobic quantum dot ZnSe/ZnS. However, the calculated PL efficiency was relatively low (0.1%) due to the luminescence quenching by water and MAA molecules. The capping ligand was also characterized by FT-IR spectroscopy, with the carbonyl stretching peak in the mercaptoacetate molecule appearing at 1575 $cm ^{-1}$. Finally, the particle sizes of the MAA capped ZnSe/ZnS were measured by TEM, showing a range of 12 to 17 nm.

• 한국약용작물학회지
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• 제24권3호
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• pp.177-182
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• 2016

Background: Many Taraxacum spp. plants are widely used in medicine, but some of them have propagation problems, such as strong dormancy and poor germination rates. This study investigated the effects of temperature, gibberellic acid ($GA_3$), and potassium nitrate ($KNO_3$) on seed germination in Taraxacum ohwianum. Methods and Results: The seeds (NIBRGR0000135524) were exalbuminous, and their length and width were $4.54{\pm}0.032mm$ and $0.97{\pm}0.029mm$, respectively. Various germination temperatures were tested (15, 20, 25, and $30^{\circ}C$), the optimum temperature for germination was found to be $20^{\circ}C$ (31.3%). High temperature ($30^{\circ}C$) resulted in non-typical seedlings (thickened and crumpled cotyledons, with a restricted root system). To increase the germination capacity, $GA_3$ (200, 500, and $1,000mg/{\ell}$) or $KNO_3$ (20, 50, 100, 200, and $500mg/{\ell}$) solutions were used as pre-soaking solutions instead of water. The $GA_3$ treatments increased the germination percentage and rate, but germination percentage was higher with the $KNO_3$ treatments. Under the $50-200mg/{\ell}\;KNO_3$ treatments, the germination percentage exceeded 80% after 12 days, and $50mg/{\ell}\;KNO_3$ was notably effective (91.2% after 15 days). Conclusions: T. ohwianum seeds showed improved germination at low temperatures. The best method for germination was presoaking in $50mg/{\ell}\;KNO_3$ for 24 h, in the dark at $4^{\circ}C$, and then incubating the germinated seed at $20^{\circ}C$ for 15 days.

• Nuclear Engineering and Technology
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• 제55권8호
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• pp.2966-2976
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• 2023

A tritium breeder is a lithium-based material capable of producing tritium. Many researchers designing nuclear-fusion energy are studying tritium production using pebbles, which are solid-type breeders. The sphericity and size of the pebbles are critical in obtaining pebbles with good tritium-breeding efficiency. Furthermore, tritium-release efficiency can be increased by using pebbles with appropriate porosities. Promising raw materials for tritium-breeding materials include Li₄SiO₄ and Li₂TiO₃. Li₄SiO₄ has a higher lithium density than Li₂TiO₃ and exhibits excellent tritium-breeding efficiency. However, it has the disadvantage of being easily decomposed during the Li₄SiO₄-green-pebble sintering process because of its low structural stability at high temperatures and high lithium density. In this study, we attempted to determine the optimal conditions for manufacturing Li₄SiO₄ pebbles using the droplet-freeze-drying method. The optimal Li₄SiO₄ slurry conditions and sintering temperatures were determined. The optimal Li₄SiO₄ slurry-fabrication conditions were 3 wt% polyvinyl alcohol and 75 wt% Li₄SiO₄ based on the deionized-water weight content. The sintering temperature at which Li₄SiO₄ did not decompose and exhibited the optimum porosity of 10.8% was 900 ℃.

• 한국식품저장유통학회지
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• 제16권5호
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• pp.656-660
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• 2009

품질이 균일한 돔배기를 제조하기 위하여 염농도와 절임온도를 달리하여 상어육을 염절임하는 동안 품질변화를 측정하였다. 염농도를 1, 2, 3%로 조정하고 $4^{\circ}C$와 $18^{\circ}C$에서 절임한 상어육의 품질변화를 비교한 결과, 수분함량은 $4^{\circ}C$, 3%의 염농도에서 절임시 64.2%로 가장 높았으며, 염함량은 $18^{\circ}C$와 3%의 염농도로 절임 하였을 때 높게 나타났고, 보수력은 저온과 높은 염농도로 절임 하였을 때 높은 것으로 나타났다. 수분활성도는 고온에서 염농도가 높을수록 낮았으며, 색차는 저온과 높은 염농도로 절임 하였을 때 낮아 외관의 변화가 적었음을 알 수 있었다. 탄력성과 강도는 저온과 높은 염농도로 절임하였을 때 높게 나타났다. 따라서 직간법으로 상어육을 염절임할 때, 높은 농도에서 염절임한 상어육의 품질이 더 우수한 것으로 나타났으며, 염절임한 상어육이 염함량을 제외하고는 $4^{\circ}C$에서 절임한 상어육의 품질이 더 우수한 것으로 나타났다.

• Membrane and Water Treatment
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• 제10권6호
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• pp.471-484
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• 2019

The complex combination of organic contaminants in the wastewater made water treatment challenging; hence, organic matter in water bodies is usually measured in terms of organic carbon. Since it is important to identify the types of compounds when deciding suitable treatment methods, this study implemented a quantitative and qualitative analysis of the organic matter content in an actual graywater sample from Ulsan, Republic of Korea using mass spectroscopy (MS). The graywater was treated using adsorption to remove the organic contaminants. Using orbitrap MS, the organic matter content between an untreated graywater and the treated effluent were compared which yielded a significant formula count difference for the samples. It was revealed that CHON formula has the highest removal count. Isotherm studies found that the Freundlich equation was the best fit with a coefficient of determination ($R^2$) of 0.9705 indicating a heterogenous GAC surface with a multilayer characteristic. Kinetics experiments fit the pseudo-second order equation with an $R^2$ of 0.9998 implying that chemisorption is the rate-determining step between the organic compounds and GAC at rate constant of $52.53g/mg{\cdot}h$. At low temperatures, the reaction between GAC and organic compounds were found to be spontaneous and exothermic. The conditions for optimization were set to achieve a maximum DOC and TN removal which yielded removal percentages of 94.59% and 80.75% for the DOC and TN, respectively. The optimum parameter values are the following: pH 6.3, 2.46 g of GAC for every 30 mL of graywater sample, 23.39 hrs contact time and $38.6^{\circ}C$.