• Korean Journal of Environmental Agriculture
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• v.42 no.4
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• pp.427-434
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• 2023

Large amounts of organic wastes generated in agricultural environments such as crop residues and livestock manure adversely affect the environment. Anaerobic digestion can reduce the amount of organic wastes and convert them into energy at the same time. Efforts are being made to further increase the energy conversion efficiency by using co-anaerobic digestion using two or more substrates. Tomatoes, rice straw, cattle manure, and cattle feces (CF) were used as substrates for anaerobic digestion. Each substrate was subjected to anaerobic digestion and the cumulative biochemical methane production potential was measured, and the biodegradability was calculated. Based on the methane production, CF and tomato were further used for co-anaerobic digestion at different mixing ratios. Among the CF:tomato ratios of 1:1, 1:2, and 2:1, 1:2 produced the most methane and the synergy index was greater 1 indicating that the co-digestion of CF and tomato improved the methane production. Overall, the results showed that the methane production from cattle manure can be improved using tomato residues.

• Proceedings of the Korean Vacuum Society Conference
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• 1999.07a
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• pp.133-133
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• 1999

비정질 탄소막 제조에 있어서 수소가 포함된 반응성 가스를 사용할 경우 제작된 탄소막 내부에는 수소가 포함되게 되며, 이러한 수소원자들은 막의 특성에 중요한 영향을 주는 것으로 알려져 있다. 따라서, 본 연구에서는 비정질 탄소막(a-C:H) 내부에 존재하는 수소가 탄소막의 특성에 미치는 영향을 알아보고, 막 내부에 포함된 수소의 함량과 공정조건 사이의 함수계를 조사함으로써 수소의 함량을 인위적으로 통제할 수 있는 가능성을 제시하고자 한다. 수소가 포함된 비정질 탄소막은 2.45 GHz의 전자기파를 사용하는 electron cyclotron resonance plasma enhanced chemical vapor deposition (ECR-PECVD) 방법과 DC magnetron sputtering 법을 사용하여 제작하였다. 기판으로는 Si(001) wafer를 사용하였으며, 아세톤과 에탄올을 사용하여 표면의 유기성분을 제거하고, 진공챔버속에서 Ar 플라즈마를 발생시켜 sputter etching 방법으로 표면을 세척하였다. ECR-PECVD 방법에서는 반응가스로 메탄(CH4)과 수소(H2)의 혼합가스를 사용하였으며, 혼합가스의 비는 5~50% 범위내에서 변화를 주었다. 수소가스의 유량은 100SCCM으로 고정하였으며, 마이크로웨이브의 power는 360~900W였고, 기판에 가해준 negative DC bias 전압은 0~-500V이었다. DC magnetron sputtering 방법에서는 반응가스로 아세틸린(C2H2) 가스를 사용하였으며, 플라즈마 발생을 용이하게 하기 위해서 Ar 가스와 혼합하여 사용하였다. Ar 가스의 유량은 10SCCM으로 고정하였으며, 아세틸렌 가스의 유량은 5~20SCCM 범위내에서 주입하였다. 이때, 기판에 가해준 negative DC bias 전압은 0~-100V이었다. 제작된 탄소막의 수소 함량을 조사하기 위하여 Fourier Transform Infrared (FTIR) 분광법과 Elastic Recoil Detection Analysis (EFDA) 법을 사용하였으며, 증착율은 SEM 단면촬영과 a-step을 이용하여 측정하였고, 막의 경도는 Micro-Hardness Testing 법을 사용하여 측정하였다.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.9
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• pp.1106-1112
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• 2007

The solvent extracts of Euphorbia helioscopia, which were extracted by using several solvents with different polarities, were prepared for utility as natural preservatives. The E. helioscopia extract by 80% ethanol was sequentially fractionated with n-hexane, dichloromethane, ethylacetate, and butanol. In order to effectively screen for a natural preservatives agent, we first investigated the antioxidant activities such as DPPH radical scavenging capacity, superoxide radical scavenging capacity, and xanthine oxidase inhibitory activity of the E. helioscopia extracts. By the screening system, we found that ethylacetate fraction had the strongest antioxidant activity in a dose-dependent manner. The antimicrobial activities and cell growth inhibition were investigated for each strain with the different concentrations of E. helioscopia extracts. Antimicrobial activities were shown in ethylacetate fraction of E. helioscopia; however, ethanol, butanol and water fractions showed weak antimicrobial activity against the tested microorganisms. Among the five fractions, ethylacetate fraction showed the highest antimicrobial activities against microorganisms tested, such as Bacillus sublitis, Listeria monocytogenes, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Salmonella Enteritidis and Salmonella Typhimurium. The polyphenol content from ethanol, n-hexane, dichloromethane, ethylacetate, butanol, and water fractions were 207.46 mg/g, 45.45 mg/g, 138.23 mg/g, 678.02 mg/g, 278.91 mg/g, and 63.76 mg/g, respectively. There seems to be a close relationship between antioxidant activities, and antimicrobial activities and polyphenol content in natural plant. From these results, it is suggested that E. helioscopia could be used for the ethylacetate fraction and could be suitable for the development of a food preservative.

• Korean Chemical Engineering Research
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• v.44 no.6
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• pp.631-635
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• 2006

To investigate the characteristics of substitute natural gas (SNG) production from direct coal methanation, the continuous lab-scale entrained flow hydrogasifier (I.D. : 0.025 m, Height : 1.0 m) was used in this experiment. The hydrogasification system consisted of high pressure gas handling system, high pressure coal feeder, entrained flow hydrogasifier, and unreacted char separator. The experiment was performed at the various conditions of reaction temperature ($600{\sim}800^{\circ}C$), $H_2$/coal ratio (0.2~0.4), and coal feed rate (0.8~2.5 g/min). Although it was shown that carbon conversion was different trends with coals from the methanation results for 6 sample coals, the carbon conversion increased with increasing reaction temperature. And it increased with increasing H2/coal ratio, whereas the concentration of CH4 decreased. Also. the carbon conversion increased with the carbon content of coal sample and had a maximum value at volatile matter content of 35 wt％.

• Korean Journal of Soil Science and Fertilizer
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• v.20 no.2
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• pp.147-151
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• 1987

This study was conducted to evaluate the effect of the liquid waste from methane fermentation on chemical components, digestible dry matter and net energy of pasture mixtures of orchard grass, tall fescue, Kentucky bluegrass and ladino clover. The total crude proteins and crude ashes increased with the application of liquid waste, but N-free extracts decreased somewhat and it didn't affect the content of crude fat and crude fiber. Amounts of neutral detergent fiber and acid detergent fiber increased with increasing application of liquid waste and the content of cellulose in cell-wall constituents decreased, but hemicellulose increased. The digestible dry matter was produced 405 kg/10a at optimum application of 42 MT/10a liquid waste compared to NPK check plot of 233 kg/10a. The starch value and net energy lactation were 291.3 KStE and 3450 MJ-NEL respectively indicating that the optimum application of liquid waste increased their values.

• Ocean and Polar Research
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• v.28 no.1
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• pp.37-43
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• 2006

In this study, bioactive components such as polyohenols, flavonoids and tocopherols were determined in cultured polar microalgae (Fragilariopsis pseudonana, Chaetoceros neogracile, Stellarima microtrias, Porosiara pseudodenticular). Antioxidant activity of methanol extracts of polar microalgae was also investigated. ${\alpha}-Tocopherol$ contents in Fragilariopsis pseudonana were almost two times higher than those of Chaetoceros neogracile in. The antioxidant activity of methanol extracts of Fragilariopsis pseudonana methanol extracts determined by ABTS assay was higher than other algae. Total polyphenol contents of methanol extracts also showed a similar trend as antioxidant activity. The protective activity against oxidative damages induced by glutamate in PC 12 cells was shown in only Chaetoceros neogracile.

• Food Science and Preservation
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• v.13 no.4
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• pp.490-494
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• 2006

Alcohol fermentation conditions were investigated using 'Cheondobansi' astringent persimmon (Diospyros kaki T.) for the study of persimmon wine and distilled liquor, The optimal yeast strain for 'Cheongdobansi' astringent persimmon alcohol fermentation was Saccharomyces kluyveri DJ97, which showed 10.8% of alcohol concentration, 96.25% of alcohol yield, and 935 ppm of methanol. The initial conditions of $22^{\circ}Brix$ and 120%(v/w) water addition resulted in the highest alcohol concentration of 10.7%. The alcohol concentration was higher in pectinase non-treated samples than in pectinase-teated samples. Lower concentrations of acetaldehyde and n-propanol were measured for the pectinase-treated sample than for the non-treatment samples. However, the methanol concentration of the pectinase-teated sample was higher than that of the pectinase non-treatment sample.

• Journal of Animal Environmental Science
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• v.17 no.sup
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• pp.7-20
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• 2011

This study was conducted to analyze the mixing ratio of raw feed materials for the methane mitigation and also to identify the minimum rearing density for improving the productivity of beef calves as eco-friendly fodder. Raw materials used in this study for the formulation of feed for methane reduction were crushed corn and alfalfa along with other 21 species. In addition, to investigate the appropriate rearing density, 12 Hanwoo calves with average weight of 150 kg was selected and experiment was conducted for four months. Methane gas emission (Bo) is about 3-4 times less in TMR 4 compared to TMR 1, 2 and 3. Feed price calculated for TMR 4 ration was also affordable. In addition, all TMRs showed a normal ruminal pH. Disappearance rate was observed to be lower in TMR 4 as compared to TMR 1, 2 and 3, but methane production decreased by 24 to 37%. The result showed improved total body weight, average daily gain and feed conversion ratio in rearing low-density ($18m^2/head$), and general treatment ($9m^2/head$) compared to overcrowding treatment ($6m^2/head$). In addition, blood components (total protein, glucose, AST, ALT and GGT factors) involved in health and disease treatments and health-related nutrition metabolism are lower in the low-density and general treatment compared to the high density treatment. Postural development (development of body size) i.e., weight, height and width significantly increased in the low and general density treatment compared to high density treatment. Especially excellent improvement was observed in low-density treatment than the general treatment. Moisture content, colonic bacteria and coccidium are higher in low and high density treatments than in the general treatment. The adequacy for beef rearing density is considered to be more desirable in an area more than $6m^2/head$. In conclusion, present study suggests that possibility of methane reduction through adjusting mixed feed ration. Also, rearing density is also an important factor in the growth and development of beef calves.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2017.04a
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• pp.127-127
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• 2017

우리나라 음식물 폐기물은 수분함량 및 유기물 함량이 높기 때문에 부패와 악취, 침출수의 원인이 된다. 하지만 이를 혐기 소화 처리한다면 구성성분에 따라 60-80%가 생분해되어(한국유기성폐자원학회, 2001) 친환경적으로 처리가능하고, 혐기소화 결과물로 발생한 메탄가스를 대체에너지로 사용할 수 있어 유기물을 효과적으로 처리할 수 있다. 그러나 유기성 폐기물은 계절 및 지역에 따라 구성성분의 비가 다르며, 성분 중 지방 함량이 많을 때 바이오가스 생산이 지연되어 생산효율 감소의 주된 원인이 된다(Kafle and Kim, 2013). 전국음식물 폐기물 중 지방함량이 높은 어육류의 발생량은 3차 조사(환경부, 2008)에 비해 2배 이상 증가하였고, 향후 음식 섭취의 서구화로 인한 육류 소비가 증가할 것으로 예상된다(환경부, 2013). 따라서 본 연구는 지방함량이 높은 유기물의 효율적 처리를 위해 지방산 종류에 따라 포화 불포화 지방산을 포함하는 부산물의 혐기소화 능력 및 바이오가스 생산 성능을 구명하는데 목적이 있다. 본 연구 결과, 불포화 지방산 함량이 높은 수준인 부산물의 바이오가스는 629.96-749.14 mL/g VS 이며, 포화 지방산 함량이 높은 수준의 부산물은 560.18-715.43 mL/g VS 였다. 불포화 지방산 함량이 25.31%-46.26%로 많아질수록 초기 순응기간은 13일에서 25일로 증가하였고, 총 바이오가스 생산량의 90%가 생산되는 기간인 T90은 57일에서 72일로 증가하여 바이오가스 생산 속도가 감소한 것으로 판단된다. 포화 지방산은 함량이 24.10-48.74%로 증가할수록 초기 순응기간의 변화는 없었고, T90은 69일에서 62일로 감소하였다. 또한 불포화 지방산이 많은 유기물은 모두 바이오가스 생산 과정에서 2단계의 지연현상을 보였지만, 포화지방산은 함량이 증가하여도 1단계의 지연현상을 보였다. 이러한 차이는 두 지방산에 관여하는 미생물의 차이(Diana, 2007)와 불포화 지방산의 굴곡된 형태가 지방산과 미생물이 상호 작용 방식에 악영향 미치기 때문으로 판단된다(Diana, 2013). 결론적으로, 두 지방산의 소화 방식은 차이가 있으며, 불포화 지방산 함량이 많은 유기물은 탄수화물 함량이 많은 유기물을 10% 이상 혼합하여 지연상을 감소시킬수 있다(Kim, 2017). 포화 지방산 함량이 많은 유기물은 초기 지연 현상 해결을 위한 연구가 추가적으로 요구된다.

• Journal of Life Science
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• v.17 no.1 s.81
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• pp.76-81
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• 2007

Inhibitory effects of methanol extracts and several solvent fractions from meju on mutagenicity in vitro genotoxicity (SOS chromotest) and growth of human cancer cells (AGS gastric adenocarcinoma and Hep 3B hepatocellular cancinoma cells) were studied. The treatment of meju methanol extracts $(100{\mu}g/assay)$ to SOS chromotest system inhibited N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) induced mutagenicity by 36%. However, the ethylacetate and dichloromethane fractions from meju methanol extracts showed the stronger antimutagenic effects (91% and 91%, respectively) in SOS chromotest. In sulforhodamine B (SRB) assay, the treatments of ethylacetate and dichloromethane fractions (2 mg/assay) significantly inhibited the growth of AGS and Hep 3B cancer cells by 64% and 71%, respectively. These results indicated that meju had inhibitor)r effects on MNNG in SOS mutagenic system and growth of human cancer cells, suggesting that its antimutagenic effect may be relative to activity of doenjang.