• Bulletin of the Korean Chemical Society
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• v.14 no.2
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• pp.275-281
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• 1993

The new high temperature plasma source for spectrochemical analysis has been developed and characterized. In the development of new high temperature plasma sources for atomic emission spectrocopy, optimization of experimental variables is necessary to achieve the best analytical results. By means of a modified sequential simplex optimization method, six experimental variables were optimized. The line-to-background (L/B) ratio for Ca(II) at 393.37 nm was used as measure of the response function. The optimal experimental conditions were found to be at a current of 27.8 A, a plasma length of 28.8 mm, a sample uptake rate of 1.3 ml/min, a sample carrier gas flow rate of 0.7 ml/min, a plasma gas flow rate of 4.9 l/min, and an observation height of 6.4 mm above the top quartz tube.

• Korean journal of food and cookery science
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• v.24 no.2
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• pp.188-197
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• 2008

This study was carried out to determine the optimal cooking conditions for various rice cultivars (Ilpoom, Saechucheong, Sindongjin, and Sura-top rice) using trial preparations with different soaking times (0, 30, and l20min) and cooking equipment (electric pressure cookers, electric cookers, gas pressure cookers, iron pots, and stone pots). In adddition, the texture and sensory characteristics of the rice prepared with the electric pressure cookers, gas pressure cookers, and stone pots were analyed. The results showed that the moisture, amylose and physicochemical compositions of the four rice varieties were similar. According to RVA, the Sura, cultivar had generally high viscosity, and the Ilpoom, cultivar presented the highest hot and peak viscosities. Saechucung had the highest initial gelatinizing temperature and Sindongjin showed the greatest setback. The optimal amounts of added water as well as heating conditons were dependent on the rice varieties, soaking times, and cooking equipment. A longer soaking time reduced the hardness of the cooked rice, amount of added water, and the heating time. The pressure cooking equipment provided the best cooked rice texture, reduced the affect of the soaking time, and decreased the heating time. In general, all the variaties of cooked rice had high overall acceptability, which tended to increase when the rice was soaked for 30min prior to cooking, had a 1.2-fold amount of water to rice added, and was cooked in the pressure equipment.

• Natural Product Sciences
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• v.21 no.2
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• pp.141-145
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• 2015

Hesperidin, which is the most abundant flavonoid of Citrus unshiu (Rutaceae), has been reported to possess diverse activities and widely used as functional foods and cosmetics. For the development of functional products, extraction procedure is indispensable. Extraction conditions affect the composition of extract as well as its biological activity. Therefore, we tried to optimize extraction conditions such as extraction solvent, extraction time and extraction temperature for maximum yield of hesperidin using response surface methodology with threelevel-three-factor Box-Behnken design (BBD). Regression analysis showed a good fit of the experimental data and the optimal condition was obtained as ethanol concentration, 59.0%; temperature $71.5^{\circ}C$ and extraction time, 12.4 h. The hesperidin yield under the optimal condition was found to be $287.8{\mu}g$ per 5 mg extract, which was well matched with the predicted value of 290.5 μg. These results provides optimized extraction condition for hesperidin and might be useful for the development of hesperidin as functional products like health supplements, cosmetics and medicinal products.

• Journal of the Korean Society of Food Culture
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• v.34 no.3
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• pp.361-368
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• 2019

The purpose of this study was to establish the best optimized extraction condition for the optimal development of fresh maca beverage using low temperature extraction and enzyme treatment. Low temperatures were applied to prevent heat-related nutritional loss during the extraction process. Best extraction conditions were investigated based on the ratio of maca to water, the ratio of enzymes, extraction temperature and time, and agitation. The optimal enzyme conditions were also examined after the treatment of cellulase:pectinase mixture to maintain the original color and flavor, as well as to increase the extraction yield. When cellulase:pectinase was 1:1, the extraction rate ranged from 77.84 to 79.29%. In addition, the best extraction rate was found when maca was mixed with twice volume of water and incubated at $45^{\circ}C$ ($84.05{\pm}0.32%$) with 90 rpm ($87.13{\pm}0.46%$) agitation for 3 hours ($84.73{\pm}0.29%$). Furthermore, sensory evaluation showed a high score in flavor, sweetness, and overall acceptability after adding 3% jujube concentrate into a fresh maca beverage.

• Journal of the East Asian Society of Dietary Life
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• v.16 no.5
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• pp.573-577
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• 2006

The rutin content of Fagopyrum tataricum is 100-fold higher than that of Fagopyrum esculentum. For the development of a rutin-containing beverage, a suitable method to extract rutin from buckwheat (Fagopyrum tataricum) with high rutin yield was investigated. A roasting temperature range of $310/240^{\circ}C$ (Ed-confirm that this is indeed a range; otherwise perhaps, 'Roasting temperatures ranging from 310 to $240^{\circ}C$ were considered$\ldots$') was considered to be the best as the basic color reference. Rutin content varied according to the roasting time and heating temperature; i.e., it decreased with increasing roasting time and temperature. (Ed- this sentence is unnecessarily complicated and should be simplified to 'Rutin content decreased with increasing roasting time and heating temperature.') The optimal extraction temperature and processing time were obtained as $80^{\circ}C$ and 10 minutes to maximize the rutin concentration in the extract.

• Reproductive and Developmental Biology
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• v.29 no.2
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• pp.117-120
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• 2005

This study was conducted to establish the optimal temperature condition before oocyte activation in B6m F1 mouse. In experiment 1, two embryo culture media (CZB vs KSOM) were evaluated for the development of activated mouse oocytes. Parthenogenetic embryos cultured in KSOM showed better blastocyst development than ones cultured in CZB $(56.2\%\;vs\;81.0\%\;p<0.01)$. Two-hour of pre-incubation before activation significantly reduced the number of hatched blastocysts in KSOM $(22.0\%\;versus\;8.8\%\;p<0.05)$. In experiment 2, recovered oocytes were pre-incubated at different temperature conditions before activation. The experimental groups were divided by 5 as follows. Group A: pre-incubation for 120 min at $37^{\circ}C$, Group B: pre-incubation at $37^{\circ}C$ for 90 min then at $25^{\circ}C$ for 30 min, Group C: pre-incubation at $37^{\circ}C$ for 60 min then at $25^{\circ}C$for 60 min, Group D: pre-incubation at $37^{\circ}C$ for 30 min then at $25^{\circ}C$ for 90 min, and Group E: pre-incubation at $25^{\circ}C$ for 120 min before activation. Group A $(67.6\%)$ and B $(66.7\%)$ showed better development to the blastocyst stage than other groups $(Group\;C:\;50.0\%\;Group \;D:\;49.2\%\;Group\;E:\;33.3\%,\;p<0.05)$. The present study indicates that the temperature before activation affects the development of B6D2 F1 mouse parthenogenetic oocytes and exposure to room temperature should be limited to 30-min when the oocytes are left in HEPES-buffered medium for micromanipulation.

• Journal of Fisheries and Marine Sciences Education
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• v.26 no.6
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• pp.1315-1321
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• 2014

We investigated the optimum salinity and temperature conditions for the mass culture of small rotifer, Proales similis. In the salinity experiment ranging from 1, 5, 10, 15, 20, 25 and 33‰, growth tended to decrease with salinity increase. Most agreeable salinity for rotifer growth was 1‰ in which maximum density and specific growth rate (SGR) were obtained. In the temperature experiments ranging from 15, 20, 25, 30 and $35^{\circ}C$, continuous growth of rotifer populations was found up to $35^{\circ}C$. The highest maximum density (2,060 inds./mL) of rotifer was observed at $25^{\circ}C$ in given temperature regime. Also, the SGR of females showed increasing tendencies with the increase of temperature. These results suggest that the optimum salinity and temperature for mass culture of P. similis may be 1‰ and $25^{\circ}C$, respectively.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.6
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• pp.761-768
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• 2013

We conducted two feeding trials to investigate the optimal feeding frequency of juvenile Korean rockfish Sebastes schlegeli fed a commercial diet of expanded pellets containing 47.2% crude protein, 9.2% crude lipid, and 14.5% ash at two different water temperatures. In the first experiment, triplicate groups of 20 fish with an average weight of 2 g were fed an equal amount of diet (5.97% based on body weight) at one of six feeding frequencies (2, 3, 4, 5, 7, or 9 meals/day) for four weeks at $17.5^{\circ}C$. After four weeks, we measured weight gain (WG), specific growth rate (SGR), feeding efficiency (FE), and protein efficiency ratio (PER). Fish fed diet five meals/day grew significantly better than those fed nine meals/day. The second experiment used identical experimental conditions and feeding regions, except the food ration was slightly less (5.92% based on body weight) and the water temperature was increased to $20^{\circ}C$. After four weeks, we again measured WG, SGR, FE and PER. Fish fed seven meals/day grew significantly faster than those fed 2, 3, 4, or 9 meals/day. Whole-body protein levels in fish fed three meals/day was higher than those fed four meals/day in $17.5^{\circ}C$ water, but whole-body lipids in the fish fed four meals/day was higher than those fed two meals/day in $20^{\circ}C$ water. A second-order polynomial analysis based on WG suggested the optimal feeding frequency for juvenile Korean rockfish was five meals/day at $17.5^{\circ}C$ and six meals/day at $20^{\circ}C$, indicating that fish reared in higher water temperature require higher feeding frequencies.

• KIEAE Journal
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• v.14 no.3
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• pp.97-103
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• 2014

This study aimed at developing integrated logic for controlling heating device and openings of the double skin facade buildings. Two major logics were developed-rule-based control logic and artificial neural network based control logic. The rule based logic represented the widely applied conventional method while the artificial neural network based logic meant the optimal method. Applying the optimal method, the predictive and adaptive controls were feasible for supplying the advanced thermal indoor environment. Comparative performance tests were conducted using the numerical computer simulation tools such as MATLAB (Matrix Laboratory) and TRNSYS (Transient Systems Simulation). Analysis on the test results in the test module revealed that the artificial neural network-based control logics provided more comfortable and stable temperature conditions based on the optimal control of the heating device and opening conditions of the double skin facades. However, the amount of heat supply to the indoor space by the optimal method was increased for the better thermal conditioning. The number of on/off moments of the heating device, on the other hand, was significantly reduced. Therefore, the optimal logic is expected to beneficial to create more comfortable thermal environment and to potentially prevent system degradation.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.68 no.4
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• pp.413-421
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• 2023

Data on salt tolerance, optimal sowing depth, soil bulk density (pb) and cardinal temperatures required for the germination and emergence of perilla (Perilla frutescens (L.) Britt) are scarce for reclaimed land soil. An experiment was conducted across six temperature treatments (10, 15, 20 , 25, 30, and 35℃) to determine the cardinal temperature for perilla seed germination and four salinity levels (0, 20, 40, and 60 mM) to determine the salt tolerance. Another experiment was performed for quantifying the emergence response of perilla to pb (1.1, 1.3, and 1.5 g cm^-3), sowing depth (1, 2, 3, and 4 cm) and soil salinity. The results revealed that increased sodium chloride levels caused a significant reduction in the seed germination at Deulhyang and Sodam. The optimum upper limit temperature was less than 35℃. The optimal sowing depth and soil bulk density were 1 cm and 1.1 g cm^-3 respectively. Perilla seedling growth was inhibited at 1.9 dS m^-1 although varying responses were observed. These results aid our understanding of the germination and emergence rate of these crops and provide data for field cultivation to optimize crop sowing in reclaimed land.