• Journal of Microbiology and Biotechnology
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• v.14 no.1
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• pp.22-28
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• 2004

Livestock industry requires alternatives of antibiotics to prevent environmental pollution and to maintain public health. We herein report on an effective method to reduce ammonia from livestock manure, and confirmed environmentally-friendly livestock production by adding three types of yeast probiotics, Pichia farinosa SKM-1, Pichia anomala SKM-T, and Galactomyces geotrichum SJM-59, into the feed stuff, separately and/or mixed, and these three types of yeasts were administered to the Hy-line brown layers for 8 weeks. Compared with control, the laying performance, the egg quality, and the number of intestinal lactic acid producing bacteria of the treated group were improved and/or increased significantly. Pichia anomala SKM-T potently reduced ammonia production from poultry manure, and the other strains were also able to reduce the ammonia from it. The optimum condition for the reduction of ammonia with Pichia farinosa SKM-1, Pichia anomala SKM-T, and Galactomyces geotrichum SJM-59 was obtained by using the augmented centroid-simplex design. The ratio of optimum condition was Pichia farinosa SKM-1:Pichia anomala SKM-T:Galactomyces geotrichum SJM-59=0.295:0.209:0.080, and the estimate was -123.36 (p=0.0l38). An ability to reduce the ammonia production from livestock manure was maintained at $30^{\circ}C$ for 15 weeks.

• KSBB Journal
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• v.22 no.4
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• pp.222-227
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• 2007

Biodiesel (fatty acid methyl esters) have used to as substitutes for petro-diesel by mixed-form with petro-diesel. In several processes of biodiesel production, alkali-catalyst transesterification produced to biodiesel of high contents with short reaction time. In this study, we investigate the optimal condition of alkali-catalyst transesterification of rapeseed oil produced at Jeju island in Korea using response surface methodology. The optimal condition of biodiesel production is reaction temperature 59.7$^{\circ}C$, catalyst amount 1.18%, oil to methanol molar ratio 1:8.75, and reaction time 5.18 min. At that reaction condition, the fatty acid methyl ester contents of product are above 97%. Our results may provide useful information with regard to the development of more economic and efficient biodiesel production system.

• Journal of the Korean Electrochemical Society
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• v.22 no.1
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• pp.1-12
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• 2019

The reduction of nitrogen to produce ammonia has been attracting much attention as a renewable energy technology. Ammonia is the basis for many fertilizers and is also considered an energy carrier that can power internal combustion engines, diesel engines, gas turbines, and fuel cells. Traditionally, ammonia has been produced through the Haber-Bosch process, in which atmospheric nitrogen combines with hydrogen at high temperature ($350-550^{\circ}C$) and high pressure (150-300 bar). This process consumes 1-2% of current global energy production and relies on fossil fuels as an energy source. Reducing the energy input required for this process will reduce $CO_2$ emissions and the corresponding environmental impact. For this reason, developing electrochemical ammonia-production methods under ambient temperature and pressure conditions should significantly reduce the energy input required to produce ammonia. In this review, we introduce the electrochemical nitrogen reduction reaction at ambient condition. Numerical studies on the electrochemical nitrogen reduction mechanism have been carried out through the computation of density function theory. Electrodes such as nanowires and porous electrodes have been also actively studied for further participation in electrochemical reactions.

• Korean Journal of Applied Biomechanics
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• v.26 no.1
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• pp.93-99
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• 2016

Objective: The purpose of this study was to investigate the effect of transcutaneous electrical nerve stimulation (TENS) treatment on maximum voluntary force (MVF) production. Methods: Ten healthy, young subjects (5 males and 5 females) participated in the study. MVF was recorded after a fifteen minute session of TENS stimulation under two conditions: low frequency (4 Hz) at maximum tolerable level and high frequency (110 Hz) at maximum tolerable level. TENS was provided simultaneously via self-adhesive electrodes placed on the finger pads of the index, middle, ring and little fingers. MVF was also recorded in a baseline condition with no TENS treatment. Data were collected in three different sessions on three consecutive days at the sametime of the day. Results: Results from the study show that on an average, MVF increasesby 25% for the index, middle and little fingers for TENS treatment with 4 Hz frequency as compared to the baseline condition. However, the 110 Hz condition did not result in a significantly different MVF than the baseline condition during individual finger pressing tasks. In addition, while producing MVF with all the four finger stogether, MVF was 30% higher for the 4 Hz conditionin comparison to the baseline condition, and 15% higher for the 110 Hz condition in comparison to the baseline condition respectively. Conclusion: The results suggest that stimulation ofafferent fibers onthe glabrous skinwith TENS could have a net facilitatory effect on the maximum motoroutput.

• Journal of the Korea Safety Management & Science
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• v.26 no.2
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• pp.23-31
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• 2024

In the military, ammunition and explosives stored and managed can cause serious damage if mishandled, thus securing safety through the utilization of ammunition reliability data is necessary. In this study, exploratory data analysis of ammunition inspection records data is conducted to extract reliability information of stored ammunition and to predict the ammunition condition code, which represents the lifespan information of the ammunition. This study consists of three stages: ammunition inspection record data collection and preprocessing, exploratory data analysis, and classification of ammunition condition codes. For the classification of ammunition condition codes, five models based on boosting algorithms are employed (AdaBoost, GBM, XGBoost, LightGBM, CatBoost). The most superior model is selected based on the performance metrics of the model, including Accuracy, Precision, Recall, and F1-score. The ammunition in this study was primarily produced from the 1980s to the 1990s, with a trend of increased inspection volume in the early stages of production and around 30 years after production. Pre-issue inspections (PII) were predominantly conducted, and there was a tendency for the grade of ammunition condition codes to decrease as the storage period increased. The classification of ammunition condition codes showed that the CatBoost model exhibited the most superior performance, with an Accuracy of 93% and an F1-score of 93%. This study emphasizes the safety and reliability of ammunition and proposes a model for classifying ammunition condition codes by analyzing ammunition inspection record data. This model can serve as a tool to assist ammunition inspectors and is expected to enhance not only the safety of ammunition but also the efficiency of ammunition storage management.

• Biotechnology and Bioprocess Engineering:BBE
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• v.2 no.2
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• pp.82-85
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• 1997

The nar promoter as an inducible promoter was characterized for the process development for the gene expression and the protein production under anaerobic condition. The LB medium was selected as a main culture medium showing the enzyme activity of 18,000 units/min/g cell in the flask cultivation. The optimum concentration of nitrate was 1%. Under anaerobic conditions, the gene expression was fully induced in the presence of nitrate.

• Proceedings of the Zoological Society Korea Conference
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• 1995.10b
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• pp.355.1-355
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• 1995

No Abstract, See Full Text

• KSBB Journal
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• v.18 no.2
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• pp.145-148
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• 2003

The hydrogen-producting bacterium was isolated from fresh water and identified as Enterbacter cloacae. The isolated was named Enterobacter cloacae YJ-1. In batch culture, The optimum cultivation temperature and pH of strain YJ-1 was 35$^{\circ}C$ and 7.5, respectively. All of the added glucose was consumed completely during fermentation even though pH was not controlled. Amount of hydrogen produced on each condition of 2% glucose, 4% sucrose and 5% fructose was 950, 1000 and 948 mL/L, respectively and resulted in increasing hydrogen production approximately 2.5-times more than controlled condition. The macimum hydrogen production was obtained when 50mM phosphate was added. was obtained when 50mM phosphate was added. In repeated0batch culture, yeast extract, but the production amount was not changed on the condition of over 0.5%, Most of the organic acides produced during the fermentation were formic and acetic acid, and propionic acid was moiety also generated.

• Natural Product Sciences
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• v.24 no.2
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• pp.103-108
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• 2018

The usage of wild ginseng (Panax ginseng C.A. Meyer) has been limited due to short supply and high price. Therefore, sufficient production as well as efficient extraction of mountain ginseng are required for the development as products. In this study, wild ginseng adventitious root cultures were prepared for efficient production with advantages of fast growth and stable production. Treatment of methyl jasmonate (MJ) to wild ginseng adventitious root cultures increased the extraction yield and antioxidative activity. Further investigation on effect of extraction conditions suggested the importance of ethanol concentration on antioxidative activity and extraction yield of MJ-treated wild ginseng adventitious root cultures. Optimized extraction condition of MJ-treated wild ginseng adventitious root cultures for maximum extraction yield and antioxidative activity was determined using response surface methodology with three-level-three-factor Box-Behnken design (BBD). Extraction of 1 g MJ-treated wild ginseng adventitious root culture with 30 ml of 9% ethanol at $30^{\circ}C$ produced 310.2 mg extract with 71.0% antioxidative activity at $100{\mu}g/ml$. Taken together, MJ-treated wild ginseng adventitious root culture is valuable source for wild ginseng usage and optimized extraction condition can be used for the development of functional products or folk remedies.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.334-334
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• 2017

Unstable soil moisture conditions often negatively affect the emergence, seedling establishment, and growth uniformity at the initial stage, and then reduce the grain yield and biomass in direct seeding cultivation for rice in rainfed fields. Therefore it is important to develop a technique to increase the rapid and stabilized seedling establishment and improve the uniformity of initial growth after sowing. This study aims to confirm results on seed priming effect of indoor using petri dish experiments can be reproduced in the field using container at Ghana. Twenty-seven rice varieties including of Oryza sativa L. and O. glaberrima Steud. were used in this study. The experiments using petri dish and container with different soil moisture conditions (5%, 10%, 15%, 20%) were compared. As a result, a significant positive correlation was found between the germination time uniformity in the primed seed of petri dish and emergence time uniformity in the primed seed of container in 10% and 15% soil moisture condition. A significant positive correlation was found between the germination time uniformity in the primed seed of petri dish and plant height in the primed seed of container in 10% soil moisture condition in O. glaberrima. This study concluded that the priming effect in petri dish demonstrate those in container in the field condition of Ghana in 10% and 15% soil moisture condition during seedling stage.