• Plant Journal
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• v.10 no.2
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• pp.38-47
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• 2014

Renewable Portfolio Standards was introduced into the system in Korea in 2012. Interest in the unutilized and renewable energy sources is increasing. and these being actively investigated. An organic rankine cycle has emerged as an alternative in order to take advantage of bio-gas engine heat of sewage treatment plants whose capacity is 1500 kW. The organic rankine cycle power system was simulated by a simulator which is a commercial program of power plant design and performance analysis. The biogas engine is operated by $460^{\circ}C$ and 2.7 kg/s flow rate in the sewage treatment plant. Working fluids(R-601a, R-123, R-245fa) are selected to use in ORC power system in this temperature range. It was the isopentane that is the best performance among three working fluids. It could be obtained net power of 163.1 kW and efficiency of 13.66% from isopentane in the simulation.

• Food Science and Preservation
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• v.16 no.5
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• pp.623-628
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• 2009

Fresh ginger rhizomes were heat-treated for 10 min, 30 min, or 60 min using hot air ($40^{\circ}C$, $50^{\circ}C$, or $60^{\circ}C$), and stored in low-density polyethylene (0.04 mm thickness) bags for 2 months at $12{\pm}1^{\circ}C$. We studied the effects of heat pretreatment on changes in gas levels after packaging, and quality characteristics of the rhizomes. Oxygen and carbon dioxide levels progressively fell and rose, respectively, as the temperature of heat treatment rose and the duration of such treatment was extended. The sprouting rate of ginger rhizomes treated at $40^{\circ}C$ was higher than that of other samples. Rotting, softening, and increasing pH of rhizomes were accelerated by treatment at higher temperature for a longer time. Weight loss and soluble solid levels were not affected by heat treatment. Sensory qualities such as appearance, odor, and overall acceptability of rhizomes fell with treatment at a higher temperature for a longer time. These results suggest that heat pretreatment has a detrimental effect on the quality of fresh ginger rhizomes.

• Tuberculosis and Respiratory Diseases
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• v.68 no.2
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• pp.62-66
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• 2010

Background: Extracorporeal membrane oxygenation (ECMO) during severe acute respiratory failure helps to recover the pulmonary function. This study evaluated our experience with veno-venous ECMO in adult patients with acute respiratory failure. Methods: From January 2007 to July 2009, ECMO was used on 54 patients. Of these 54 patients, 7 were placed on veno-venous ECMO for acute respiratory failure. The indications of ECMO were based on the lung dysfunction measured as a $PaO_2/FiO_2$ ratio <100 mm Hg on $FiO_2$ of 1.0, or an arterial blood gas pH <7.25 due to hypercapnia despite the optimal treatment. $EBS^{(R)}$, $Bio-pump^{(R)}$, and Centrifugal Rotaflow $pump^{(R)}$ were used and all cannulations were performed percutaneously via both femoral veins. When the lung function was improved, an attempt was made to wean on ECMO at moderate ventilator settings followed by decannulation. Results: Five of the 7 patients were male and the mean age was $46.3{\pm}18.3$. The causes of acute respiratory failure were 3 cases of pneumonia, 2 near-drownings, 1 pulmonary hemorrhage due to acute hepatic failure and 1 mercury vapor poisoning. The mean support time of ECMO was $17.3{\pm}13.7$ days. Of the 7 patients implanted with ECMO, 5 patients (71%) were weaned off ECMO and 3 patients (43%) survived to hospital discharge after a mean 89.6 hospital days. Conclusion: The early use of ECMO for acute respiratory failure in adults due to any cause is a good therapeutic option for those unresponsive to the optimal conventional treatments.

• Korean Journal of Food Science and Technology
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• v.41 no.4
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• pp.374-379
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• 2009

In this study, we investigated effects of different packaging materials and methods on physico-characteristics of green pumpkin during storage at $10^{\circ}C$. Whole green pumpkin samples were packaged with polyvinyl chloride film (PVCF), orange coating film (OCF), paraffin film (PF), or paper with paraffin film (PWPF) and stored at $10^{\circ}C$. Weight loss, pH, firmness, browning, and gas composition ($O_2$ and $CO_2$) inside the film packages were evaluated. All characteristics of the unpackaged group (control group, CON) changed rapidly and lost marketability as compared with the packed pumpkin group. The pH values in all of the green pumpkin samples were between 6.38 and 6.67, and decreased with increased storage time. Over the storage time, all packaged pumpkin groups evidenced prevented or retarded deterioration of the green pumpkin samples in terms of appearance, texture, and discoloration. Firmness decreased slightly with increased storage time. Brown color difference were much higher in the controls than in the film-packaged green pumpkin samples, and increased rapidly in the early stages of storage. These results were attributed to reduce respiration rates as a result of elevated carbon dioxide and reduced oxygen levels in the packages. The results of this study demonstrated that the green pumpkin packaged with PWPF and PVCF showed retarded deterioration as compared to the CON, OCF and PF samples in a controlled atmosphere, and thus significant differences were noted according to the packaging material and methods used.

• Korean Journal of Organic Agriculture
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• v.22 no.3
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• pp.491-502
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• 2014

The present study was conducted to investigate effective starter culture to improve biological activity of Asarum sieboldii. Antibacterial activity, antioxidant activity and reduction of enteric rumen methane production were used as criterions for biological activity. Ground A. sieboldii was added in MRS broth at 10% (w/v) and fermented by different starter cultures. Weissella confusa NJ28, Weissella cibaria NJ33, Lactobacillus curvatus NJ40, Lactobacillus brevis NJ42, Lactobacillus plantarum NJ45 and Lactobacillus sakei NJ48 were used for starter culture strains. Each starter culture was inoculated with 1% (v/v) ratio and fermentation was performed at $30^{\circ}C$ with agitation (150 rpm) for 48 h. MRS broth for the control was employed without starter culture. Then the fermentation growth was dried and extracted using ethyl alcohol. The growth of starter culture was detected at NJ40, NJ42, NJ45 and NJ48. And the highest cell growth was found in NJ40. Antibacterial activity against to Staphylococcus aureus, Listeria monocytogens, Mannheimia haemolytica and Salmonella gallinarum were observed in the extract fermented by NJ40 and NJ45. All treatments showed antioxidant activities, however, there were no significant differences (p>0.05). In in vitro rumen fermentation, negative control (NC) and positive control (PC) were assigned to without extract and with non-fermented A. sieboldii extract. Significant suppression of gas productions were detected in positive control and treatments compared to negative control (p<0.05). However, total volatile fatty acid production was not suppressed. Significant methane reduction per total volatile fatty acid productions were found in positive control and NJ45 treatment (p<0.05). The present study suggested a fermentation of A. sieboldii using NJ45 strain could improve its biological activity and make possible for its use in bio additive for enteric rumen methane mitigation without suppression of animal productivity.

• Journal of Life Science
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• v.29 no.10
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• pp.1120-1125
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• 2019

The short-lived nematode Caenorhabditis elegans has been used as a model organism for many studies, including lifespan extension. To screen common seaweeds for natural anti-aging agents, the lifespan of C. elegans (N2 wild-type strain) was measured by its hatch rate, growth rate, survival rate, chemotaxis, brood size, and egg-laying time after exposure to nematode growth medium (NGM) containing seaweed extracts. Approximately 30 animals synchronized at the first larval stage were incubated until they reached their adult stages before laying their eggs and were transferred to fresh NGM every 3 days. We also identified the major active compound from the seaweed by gas chromatography-mass spectrometry and tested its optimal dose for longevity. Of 13 common seaweed species, an ethanol extract of the brown seaweed Hizikia fusiformis showed the greatest effect on hatching, growth, and survival rates. The lifespan of C. elegans was significantly expanded 1.54-fold and 1.23-fold in the presence of the ethanol extract (0.05 mg/ml) and the main active component, fucosterol (0.05 mg/ml), respectively. Exposure to the ethanol extract also increased chemotaxis 1.13-fold, decreased brood size 0.74-fold, and shortened egg-laying time 0.96-fold. These results suggest that the aquaculturable H. fusiformis may be a promising source of a diet supplement to support health care.

• Journal of Life Science
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• v.29 no.2
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• pp.223-230
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• 2019

Ozone is a gaseous molecule able to kill microorganisms, such as yeast, fungi, bacteria, and protozoa. However, ozone gas is unstable and cannot be used easily. In order to utilize ozone properly and efficiently, plant oil can be employed. Ozone reacts with C-C double bonds of fatty acids, converting to ozonized oil. In this reaction, ozonide is produced within fatty acids and the resulting ozonized oil has various biological functions. In this study, we showed that ozonized oil has antimicrobial activity against fungi and bacteria. To test the antimicrobial activity of ozonized oil, we produced ozonized olive oil. Ozonized olive oil was applied to Staphylococcus aureus, methicillin-resistant Staphylococcus aureus (MRSA), Staphylococcus epidermidis, Pseudomonas aeruginosa, Escherichia coli, and Candida albicans. Antimicrobial activity was assayed using the disk diffusion method following the National Committee for Clinical Laboratory Standards. Minimal inhibitory concentrations (MIC) were 0.25 mg for S. aureus, 0.5 mg for S. epidermidis, 3.0 mg for P. aeruginosa, and 1.0 mg for E. coli. Gram positive bacteria were more susceptible than Gram negative bacteria. We compared growth inhibition zones against S. aureus and MRSA, showing that the ozonized olive oil was more effective on MRSA than S. aureus. Furthermore, the ozonized olive oil killed C. albicans within an hour. These data suggested that ozonized olive oil could be an alternative drug for MRSA infection and could be utilized as a potent antimicrobial and antifungal substance.

• Applied Chemistry for Engineering
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• v.22 no.5
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• pp.562-565
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• 2011

In this study, we developed a bioprocess using Clostridium ljungdahlii as a biological catalyst to produce bio-ethanol, and the effect of pH on microbial growth and ethanol production was investigated. From the results of fermentation at various initial pH condition without pH control, pH of fermentation broth decreased to 4.5 within 24 h due to accumulation of by-product acetic acid and both microbial growth and ethanol production were stopped. The experimental result of initial pH 8 showed the highest microbial growth and ethanol production (0.53 g/L), since the pH drop was relatively slow. From the experiment of pH 7 maintained fermentation using pH controllable bioreactor, the maximum cell dry weight of 1.65 g/L and the maximum ethanol concentration of 1.43 g/L were obtained within 24 h. In conclusion, the C. ljungdahlii growth was enhanced by pH maintenance of neutral range, and the ethanol production was also enhanced based on the growth-associated ethanol production characteristics of C. ljungdahlii.

• Journal of Appropriate Technology
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• v.7 no.1
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• pp.59-71
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• 2021

Hybrid hydrothermal carbonization (Hybrid HTC) technology is a proprietary thermochemical process for two or more organic wastes.The reaction time is less than two hours with temperature range 180~250℃ and pressure range 20~40bar. Thanks to accumulation of the carbon of the waste during Hybrid HTC process, the energy value of the solid fuel increases significantly with comparatively low energy consumption. It has also a great volume reduction with odor removal effect so that it is evaluated as the best solid fuel conversion technology for various organic wastes. In this study of the hybrid hydrothermal carbonization, the effect on the calorific value and yield of Cambodian mango waste were evaluated according to changes in temperature and reaction time. Through the study, parameter optimization has been sought with improving energy efficiency of the whole plant. It is decomposed in the Hydro-Carbonation Technology to Generate Gas. At this time, it is possible to develop manufacturing and production technologies such as hydrogen (H₂) and methane (CH₄). Based on the results of the study, a pilot plant (2t/day) has been proposed for future commercialization purpose along cost analysis, mass balance and energy balance calculations.

• Korean Journal of Veterinary Service
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• v.45 no.2
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• pp.111-116
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• 2022

The purpose of this study is to evaluate the reduction effect of microbially activated peat on odor generated by livestock farms. The odor gas was measured by stirring the livestock manure sample with the existing litter and the microbially activated peat (Healtha Peat) was developed by this research team. In outdoor farm experiment, the measurements were performed by comparing broilers farm using rice husks and microbially activated peat as litter. The weight, mortality, shipment date, and odor levels (NH₃) were measured before and after experiment. The result showed that NH₃ levels were reduced by 100% in the Healtha Peat mixed group, Healtha Peat and rice husks mixed group. In the peat mixed group, Healtha Peat and saw dust mixed group showed reduce value at 99.6% and 99.1%, respectively. However the rice husks mixed group and saw dust mixed group showed a relatively weak NH₃ reduction effect with values of 57.5% and 84.8%, respectively. After 3 months, the Healtha Peat mixed group and Healtha Peat and rice husks mixed group showed the highest NH₃ reduction effect persistence. In the outdoor farm experiment, NH₃ was present in farms using rice husks, but not in farms using Healtha Peat. In farms using Healtha Peat, the mortality and NH₃ were reduced by 75% and >90%, respectively. The average body weight increased 18% and resulted to 10% decrease in the shipping date. These results implied that microbially activated peat has a clear effect on farm NH₃ reduction and affects the productivity of farm animals.