• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.4
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• pp.465-472
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• 2017

In this study, tuna sawdust was added to extruded meat analog in order to develop a meat analog with high quality. Addition of tuna sawdust has merit for utilizing a byproduct from poultry processing. Physicochemical characteristics were examined through the extrusion cooking process. The basic mixture of sample mixed with 65% deffated soy flour 25% isolated soy protein, and 10% corn starch was setup as the raw material. Three kinds of samples were made in total by addition of 15% and 30% tuna sawdust to this mixture. The extrusion process had a screw speed of 250 rpm, die temperature of $140^{\circ}C$, and moisture content of 50%. As addition of tuna sawdust increased, breaking strength and density decreased, specific length increased, and integrity and water holding capacity decreased. Likewise, nitrogen solubility index and protein digestibility decreased as addition of tuna sawdust increased. DPPH radical scavenging activity increased as addition of tuna sawdust addition, whereas it decreased as storage period increased to 30 or 60 days. The value of rancidity decreased as addition of tuna sawdust increased. However, 60 days later, radical scavenging activity increased more or less, and a significant difference was detected 150 days later. In conclusion, addition of tuna sawdust increased soft texture, and nutrition of the basic mixture sample. The process promoting functionality such as improvement of antioxidant function was confirmed through this study.

• Journal of the Korean Institute of Gas
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• v.21 no.2
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• pp.1-9
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• 2017

Enhanced coalbed methane recovery (ECBM), as injecting $CO_2$ or $N_2$ into the coalbed methane (CBM) reservoir for increasing methane recovery, takes center stage in these days. ECBM makes a better recovery than the conventional production method, it called dewatering process. However the characteristics of injection gas affect to methane recovery, thus analysis on the mixed ratio of injection gas should be required. In this study, CBM reservoir model was built to estimate the methane recovery of ECBM method by different mixed ratio of injection gas. Additionally, to consider the characteristics of injection gas such as carbon captured storage, nitrogen re-injection, etc. economic analysis was performed. The results showed that ECBM cases produced methane almost twice as much as dewatering case and $CO_2$ 10% and $N_2$ 90% case resulted in the highest methane recovery among the mixed gas cases. On the other hand, the results of economic analysis showed that $CO_2$ 20% and $N_2$ 80% case made the highest total production profit. Therefore, both the recovery of methane and economical efficiency should be considered to apply ECBM process.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.6
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• pp.773-779
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• 2009

The physicochemical characteristics of abalone meat aged in Kochujang at $20^{\circ}C$ were studied. Moisture contents of Kochujang, which contained raw, roasted, and steamed abalone, increased to 14.9, 10.7, and 7.8%, respectively, compared to control at day 1. The moisture contents of all products were equilibrated at 53.5% approximately after 2 weeks. Hunter's L, a, and b values increased in all products. Total microbial counts were 5.74, 5.70, and 5.83 log CFU/g in the products and increased to 0.28, 0.30, 0.11 log CFU/g, respectively, after 28 days storage at $20^{\circ}C$. After 8 days, the pH in the steamed abalone meat decreased gradually from 5.48 to 5.16 and the titratable acidity was the highest at day 14. Volatile base nitrogens of raw, roast, and steamed abalone were 1.4, 0.9, and 2.7 mg%, but the values in the Kochujang products were 14.0, 13.8, and 11.6 mg% at day 1, and 15.5, 13.3 and 11.3 mg% at day 8, respectively. Quality of the product prepared with steamed abalone was the most acceptable by sensory evaluation.

• Safety and Health at Work
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• v.9 no.3
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• pp.356-359
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• 2018

This case report attempts to present a case of acute toxic hepatitis in fire extinguisher manufacturing workers exposed to 2,2-dichloro-1,1,1-trifluoro-ethane (HCFC-123) in August 2017 in Korea. Twenty-two-year-old male workers were exposed to HCFC-123 for 1.5 hours one day and for 2.5 hours the other day, after which one worker died, and the other recovered after treatment. The workers were diagnosed with acute toxicity of hepatitis. However, exposure levels of HCFC-123 were not known with no work environment measurement done. Therefore, this study was conducted to estimate the exposure concentration of HCFC-123 via a job simulation experiment. In the simulation, the HCFC-123 exposure concentration was measured with the same working practice and working time as with the workers aforementioned. As a result, the workers who infused HCFC-123 into storage tanks were estimated to be exposed to HCFC-123 at a concentration of $20.65{\pm}10.81ppm$, and a mean concentration of area samples within a working radius were estimated as $70.30{\pm}18.10ppm$. Valve assembly workers working on valves of a fire extinguisher filled with HCFC-123 were exposed to HCFC-123 at concentrations of $91.65{\pm}4.03ppm$ and $115.55{\pm}7.28ppm$, respectively, in the simulation, and area samples simulated within the working radius were also found to be high with concentrations of $122.75{\pm}91.15ppm$ and $126.80{\pm}60.25ppm$, respectively. Nitrogen gas packing workers, who did not handle HCFC-123 directly, were exposed to the agent at a concentration of $71.80{\pm}8.49ppm$. These results suggest that exposure to HCFC-123 at high concentrations for 1.5-2.5 hours caused acute toxic hepatitis in two workers.

• Korean Journal of Food Science and Technology
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• v.38 no.1
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• pp.75-81
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• 2006

Effects of medicinal herbs and bee propolis on pork quality were assessed using formulae A (control), B (boiling water extraction with propolis), and C (boiling water extraction without propolis). Seasoning sauce was made with medicinal herb, spices, total flavonoid, and soy sauce with/without 0.4% propolis (21.8 mg/g), mixed with pork, and stored at low temperature $(4{\pm}1^{\circ}C)$ for 20 days. In formula B peroxide value and thiobarbituric acid content increased with increasing storage period. Formula B showed highest Volatile Basic Nitrogen (VBN) and lowest microbial counts, followed by formulae C and A, receiving higher scores for taste and fragrance.

• Food Science and Preservation
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• v.16 no.4
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• pp.525-533
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• 2009

To explore cattail pollen powder as a functional food ingredient, we analyzed the general components of pollen powder, tested changes in the physical properties of dough containing the powder, and investigated the process ability of powder-containing dough in bread making by adding 3%, 6%, or 9% by weight of pollen powder to wheat flour. Cattail pollen powder consisted of (all w/w) 12.7-13.2% water, 15.7-17.8% crude protein, 1.3% crude fat, 7.5-7.7% free sugar, 14.7-18.6% crude fiber, 3.4-4.9% pollen, and 49.7-55.9% soluble nitrogen-free extract (NFE). Analysis of the physical properties of dough mixed with pollen powder showed that as more pollen powder was added, the absorption rate increased, but dough stability decreased. With increasing levels of cattail pollen powder, the falling number decreased, and amylase activity increased. Fermentability was highest in dough made with 3% by weight of pollen powder, and the bread product made from such dough had the greatest volume. As more cattail pollen powder was added, the moisture activity in dough tended to decrease to a greater extent than seen in control dough, and this tendency increased with time. We found that longer storage periods were associated with greater hardness and springiness, which indicated degradation in product quality. Therefore, it is suggested that bread products containing cattail pollen powder should be consumed within 3 days of preparation. In a taste survey, bread baked with 3% (w/w) cattail pollen powder scored highest in all questionnaire items.

• Journal of Ecology and Environment
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• v.43 no.1
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• pp.43-60
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• 2019

Background: Tropical montane forests played an important role in the provision of ecosystem services. The intense degradation and deforestation for the need of agricultural land expansion result in a significant decline of forest cover. However, the expansion of agricultural land did not completely destruct natural forests. There remain forests inaccessible for agricultural and grazing purpose. Studies on these forests remained scant, motivating to investigate biomass and soil carbon stocks. Data of biomass and soils were collected in 80 quadrats ($400m^2$) systematically in 5 forests. Biomass and disturbance gradients were determined using allometric equation and disturbance index, respectively. The regression modeling is employed to explore the spatial distribution of carbon stock along disturbance and environmental gradients. Correlation analysis is also employed to identify the relation between site factors and carbon stocks. Results: The result revealed that a total of 1655 individuals with a diameter of ${\geq}5cm$, representing 38 species, were measured in 5 forests. The mean aboveground biomass carbon stocks (AGB CS) and soil organic carbon (SOC) stocks at 5 forests were $191.6{\pm}19.7$ and $149.32{\pm}6.8Mg\;C\;ha^{-1}$, respectively. The AGB CS exhibited significant (P < 0.05) positive correlation with SOC and total nitrogen (TN) stocks, reflecting that biomass seems to be a general predictor of SOCs. AGB CS between highly and least-disturbed forests was significantly different (P < 0.05). This disturbance level equates to a decrease in AGB CS of 36.8% in the highly disturbed compared with the least-disturbed forest. In all forests, dominant species sequestrated more than 58% of carbon. The AGB CS in response to elevation and disturbance index and SOC stocks in response to soil pH attained unimodal pattern. The stand structures, such as canopy cover and basal area, had significant positive relation with AGB CS. Conclusions: Study results confirmed that carbon stocks of studied forests were comparable to carbon stocks of protected forests. The biotic, edaphic, topographic, and disturbance factors played a significant variation in carbon stocks of forests. Further study should be conducted to quantify carbon stocks of herbaceous, litter, and soil microbes to account the role of the whole forest ecosystem.

• Ecology and Resilient Infrastructure
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• v.6 no.2
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• pp.79-88
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• 2019

In order to study the water quality status and its causal environmental factors, the water quality variables of chemical oxygen demand (COD), chlorophyll a (Chl a), Total phosphorus (TP), and total nitrogen (TN), the hydrogeomorphologic variables of water level fluctuation, total water storage, dam elevation, watershed area, and shoreline development index, and the land cover variables of forest, agricultural area, and urbanized area in the watershed were investigated in total 73 reservoirs with various operational purposes, water level fluctuation and geographical distribution in South Korea. The water quality was more eutrophic in the reservoirs of the more urbanized and agricultural area in the watershed, the low altitude, the narrow water level fluctuation, the narrowed watershed area, and the more circular shape. In terms of the purposes of reservoir operation, the reservoirs for agricultural irrigation were more eutrophic than the reservoirs for flood control. The results of the variable selection and path analysis showed that COD determined by Chl a and TP was directly affected by water level fluctuation and the shoreline development of the reservoirs. TP was directly affected by the urbanized area of the watershed which was related to the elevation of the reservoir. TP was also influenced by the water level fluctuation and the shoreline development. In conclusion, the eutrophication of the reservoirs in Korea would be influenced by the land use of the watershed, hydrological and geographical characteristics of the reservoir, water level fluctuation by the anthropogenic management according to the reservoir operation purpose, and the location of the reservoirs.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.221-221
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• 2015

Sustainable use of water resource and conservation of water quality are essential problems in the world. Especially, problems of water quality are serious one for human health as well as ecological system of all creatures on the earth. Recently, the importance of total effluent load as well as the concentrations of pollutant materials has been recognized not only for the conservation of water quality but also for sustainable water use in watersheds. However, the measurement or estimation of total effluent load from non-point source area such as farm lands or forests may be more difficult because both of concentration and discharge of the water are greatly changed depending on various factors especially metrological conditions such as rainfall, while the measurement from a point source area may be easy because the concentration of pollutant materials and amount of discharge water are relatively steady. Therefore, the total effluent load from a non-point source is often estimated by statistical relationships between concentration and discharge, which is called as L-Q equation. However, a lot of work and time are required to collect and analyze water samples and to get the accurate relationship or regressive equation. So, we proposed a new system for direct measurement of total effluent load of water quality from non-point source areas to solve the problem. In this system, the overflow depth at a hydraulic weir is measured with a pressure gage every hourly interval to calculate the amount of hourly discharge at first. Then, the operating time of a small electric pump to collect an amount of water which is proportional to the discharge is calculated to intake the water into a storage tank. The stored water is taken out a few days later in a case of storm event or several weeks later in a case of non-rainfall event and the concentrations of water quality such as total nitrogen and phosphorous are analyzed in a laboratory. Finally, total load of the water quality can be calculated by multiplying the concentration by the total volume of discharge. The system was installed in a small experimental forestry watershed to check the performance and know the total load of water quality from the forest. It was found that the system to collect a proportional amount of water to actual discharge operated perfectly and a total load of water quality was analyzed accurately. As the result, it was expected that the system will be very available to know the total load from a non-point source area.

• Journal of Plant Biotechnology
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• v.49 no.3
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• pp.187-192
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• 2022

The repeated monthly or weekly subculture of plant callus is labor intensive and increases the risk of somaclonal variation from the parental callus line. The most effective method for preserving plant callus is cryopreservation, which involves storage in liquid nitrogen. However, this method cannot be applied to the callus of different plant species in the same manner, so it is difficult to develop a standardized cryopreservation method. In addition, the survival rate of the frozen callus after thawing and the regeneration rate after survival are uncertain. Therefore, it is necessary to develop a method to extend the subculture interval of plant callus in an active state. In this study, active plant calli of various species without freezing was incubated at 15℃ for 4 to 12 weeks without subculture. After 12 weeks, 8 lines of plant callus grew less than 2-fold when cultured at 25℃, but at least 2 times as much when cultured at 15℃. Moreover, total antioxidant activity did not differ significantly between plant callus recovered at 25℃ after culturing at 15℃ or at 25℃. These results show that the subculture interval can be extended at a temperature of 15℃ without need for modified medium composition or additional processes. In addition, positive results in all calli of several plant species are expected to reduce labor as well as somaclonal variation by increasing the subculture.