• Korean Journal of Organic Agriculture
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• v.23 no.2
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• pp.335-346
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• 2015

The objective of this study was to evaluate the effect of dietary rosemary on performance, microflora population in cecum and noxious gas emission from litter of broiler. A total of 216 broiler chicks at 7 days old were fed the commercial diet (control), added 0.5% level of dried rosemary leaves (5 g/kg diet, T1) and 1.0% level of dried rosemary leaves (10 g/kg diet, T2) for 4 weeks. The body weight gain and feed conversion ratio were improved by feeding rosemary at 7 to 35 days of age (P<0.05), but there was no difference between T1 and T2. Amount of feed intake and mortality were not different among the three group. There was an increase in the microflora population of Lactobacillus (P<0.05) and decreased in E. coli and salmonella (P<0.05) in the cecum contents at 21 and 35 days of age. Emission of ammonia gas from litter was significantly decreased by supplementary rosemary at 21 to 35 days of age (P<0.05), but there was no difference between T1 and T2. These results indicated that feeding 0.5 to 1.0% level of dried rosemary leaves during broiler production improved in the body weight gain and feed conversion ratio because of increasing nutrient digestibility from feed, also increase in intestinal beneficial bacteria and decrease in harmful bacteria in the cecum contents, and decreasing emission of ammonia gas from litter.

• Journal of the Korean Institute of Gas
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• v.18 no.3
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• pp.38-43
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• 2014

This paper is to analyze and study the failure examples of fire by inflammables and electric contact faulty in interior of vehicle. The first example, the driver used to air freshener that remove the air conditioner bad smell. He get out of a car. And then, he put it on the crash pad. Before long, a fire breaks out because of explosion solar radiation. The second example, the driver used in room of a car. It certified the fire by disconnection phenomenon happened the electric overload. The third example, the driver install the heat rays to warm his body, In the initial stages, it didn't seek the dangerous of fire during using a car to 5,000km. This heat rays become to down durability so that produced the electric overload in an instant. The fourth example, after the man smoked the cigarette on riding with rear seat, he put it on seat in vehicle no extinguishing the burning cigarette. It knew the fact that burnt to ashes a car by on well combustible paper. Thus, the driver must consider a countermeasure for minimize the fire production when he use the inflammable and install adding electric system.

• Korean Journal of Agricultural Science
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• v.29 no.2
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• pp.35-42
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• 2002

This study was conducted to investigate the effects of the addition of activated charcoal (AC) and oak charcoal on in vitro ruminal fermentation characteristics, nutrient disappearance, and ruminal gas production. AC and oak charcoal were added at the levels of 0.50, and 1.00 % to experimental diet (roughage/concentrate ratio ; 2/8). Ruminal pH and ammonia-N tended to increase by adding AC(P<0.05). But oak charcoal did not affect the ruminal pH and ammonia-N. Although not significant, ruminal total VFA and molar percentage of butyric acid tended to decrease in AC diets. but molar percentage of acetate and propionate were not affected by adding AC. Ruminal degradation of dry matter, crude protein, NDF, and ADF in AC diets tended to increase than in non-AC diet, however, no tendency in ruminal degradation of hemicellulose was observed. Ruminal gas production tended to increase in the AC and oak charcoal diets(P<0.05). Although there appeared some beneficial effects in adding AC to ruminant diets in this study, more works should be done with AC before we can make clear conclusion on the use of AC in the ruminant diets.

• Journal of Bio-Environment Control
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• v.14 no.3
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• pp.218-231
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• 2005

This paper reviews the engineering approach needed to support humans during their long-term missions in space. This approach includes closed plant production systems under microgravity or low pressure, mass recycling, air revitalization, water purification, waste management, elimination of trace contaminants, lighting, and nutrient delivery systems in controlled ecological life support system (CELSS). Requirements of crops f3r space use are high production, edibility, digestibility, many culinary uses, capability of automation, short stems, and high transpiration. Low pressure on Mars is considered to be a major obstacle for the design of greenhouses fer crop production. However interest in Mars inflatable greenhouse applicable to planetary surface has increased. Structure, internal pressure, material, method of lighting, and shielding are principal design parameters for the inflatable greenhouse. The inflatable greenhouse operating at low pressure can reduce the structural mass and atmosphere leakage rate. Plants growing at reduced pressure show an increasing transpiration rates and a high water loss. Vapor pressure increases as moisture is added to the air through transpiration or evaporation from leaks in the hydroponic system. Fluctuations in vapor pressure will significantly influence total pressure in a closed system. Thus hydroponic systems should be as tight as possible to reduce the quantity of water that evaporates from leaks. And the environmental control system to maintain high relative humidity at low pressure should be developed. The essence of technologies associated with CELSS can support human lift even at extremely harsh conditions such as in deserts, polar regions, and under the ocean on Earth as well as in space.

• Proceedings of the Korean Vacuum Society Conference
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• 2000.02a
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• pp.188-188
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• 2000

DLC (Diamond-Like Carbon) 박막은 높은 경도와 가시광선 및 적외선 영역에서의 광 투과도, 전기적 절연성, 화학적 안정성 및 저마찰.내마모 특성 등의 우수한 물리.화학적인 물성을 갖고 있기 때문에 여러 분야의 응용연구가 이루어지고 있다. 이러한 DLC 박막을 제작하는 과정에는 여러 가지가 있으나, 본 연구에서는 ECR-PECVD electron cyclotron resonance plasma enhanced chemical vapor deposition) 방법을 사용하였다. 이것은 최근에 많이 이용되고 있는 방법으로, 이온화률이 높을뿐만 아니라 상온에서도 성막이 가능하고 넓은 진공도 영역에서 플라즈마 공정이 가능한 장점이 있다. 기판으로는 4" 크기의 S(100)를 사용하였고, 박막을 제작하기 전에 진공 중에서 플라즈마 전처리를 하였다. 플라즈마 전처리는 Ar 가스를 150SCCM 주입시켜 5$\times$10-1 torr 의 진공도를 유지시키면서, ECR power를 700W로 고정하고, 기판 bias 전압을 -300 V로 하여 5분 동안 기판을 청정하였다. DLC 박막은 ECR power를 700W. 가스혼합비와 유량을 CH4/H2 : 10/100 SCCM, 증착시간을 2시간으로 고정하고, 기판 bias 전압을 0, -50, -75, -100, -150, -200V로 변화시켜가면서 제작하였다. 이때 ECR 소스로부터 기판까지의 거리는 150mm로 하였고, 진공도는 2$\times$10-2torr 였으며, 기판 bias 전압은 기판에 13.56 MHz의 RF power를 연결하여 RF power에 의해서 유도되는 negative DC self bias 전압을 이용하였다. 제작된 박막을 Auger electron spectroscopy, elastic recoil detection, Rutherford backscattering spectroscopy, X-ray diffraction, secondary electron microscopy, atomic force microscoy, $\alpha$-step, Raman scattering spectroscopu, Fourier transform infrared spectroscopy 및 micro hardness tester를 이용하여 기판 bias 전압이 DLC 박막의 특성에 미치는 영향을 조사하였다. 분석결과 본 연구에서 제작된 DLC 박막은 탄소와 수소만으로 구성되어 있으며, 비정질 상태임을 알 수 있었다. 기판 bias 전압의 증가에 따라 박막의 두께가 감소됨을 알 수 있었고, -150V에서는 박막이 거의 만들어지지 않았으며, -200V에서는 기판 표면이 식각되었다. 이것은 기판 bias 전압과 ECR 플라즈마에 의한 이온충돌 효과 때문으로 판단되며, 150V 이하에서는 증착되는 양보다 re-sputtering 되는 양이 더 많을 것으로 생각된다. 기판 bias 전압을 증가시킬수록 플라즈마에 의한 이온충돌 현상이 두드러져 탄소와 결합하고 있던 수소원자들이 떨어져 나가는 탈수소화 (dehydrogenation) 현상을 확인할 수 있었으며, 이것은 C-H 결합에너지가 C-C 결합이나 C=C 결합보다 약하여 수소 원자가 비교적 해리가 잘되므로 이러한 현상이 일어난다고 판단된다. 결합이 끊어진 탄소 원자들은 다른 탄소원자들과 결합하여 3차원적 cross-link를 형성시켜 나가면서 내부 압축응력을 증가시키는 것으로 알려져 있으며, hardness 시험 결과로 이것을 확인할 수 있었다. 그리고 표면거칠기는 기판 bias 전압을 증가시킬수록 더 smooth 해짐을 확인하였다.인하였다.

• Journal of the Korea Organic Resources Recycling Association
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• v.29 no.4
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• pp.55-65
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• 2021

This study investigated methane productions and a degradation rate of organic matters by German standard method, VDI4630 test. In this study, 11 waste biomasses from agricultural fields were selected for the investigation. The objective of this study was to estimate a distribution of organic matters by using the Double first-order kinetics model in order to calculate the rate of biodegradable organic matters which degrade rapidly in the initial stage and the persistently biodegradable organic matters which degrade slowly later. As a result, all the biomasses applied in this study showed rapid decomposition in the initial stage. Then the decomposition rate began to slow down for a certain period and the rate became 10 times slower than the initial decomposition rate. This trend of decomposition rate changes is typical conditions of biomass decompositions. The easily degradable factors (k₁) were raged between 0.097~0.152 day^-1 from vegetable crops and persistent degradable factor (k₂) were 0.002~0.024 day^-1. Among these results, greater organic matter decomposition rates from VDI4630 had greater k₁ values (0.152, 0.144day^-1) and smaller k₁ values (0.002, 0.005day^-1) from cucumbers and paprika. In a meanwhile, radishes and tangerine rinds which had low decomposition rates showed 0.097 and 0.094 day^-1 of k₁ values and decomposition rates seems to affect k₁ values.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.4
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• pp.515-523
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• 2012

The study investigated the biochemical methane potential (BMP) assay of cellulose supplementing with mixed methanogens and cellulolytic bacteria to improve anaerobic digestion for methane production. For the BMP assay, 7 different microbial supplementation groups were consisted of the cultures of mixed methanogens (M), Fibrobacter succinogenes (FS), Ruminococcus flavefaciensn (RF), R. albus (RA), RA+FS and M+RA+FS including control. The cultures were added in the batch reactors with the increasing dose levels of 1% (0.5 mL), 3% (1.5 mL) and 5% (2.5 mL). Incubation for the BMP assay was carried out for 40 days at $38^{\circ}C$ and anaerobic digestate obtained from an anaerobic digester with pig slurry as inoculum was used. In results, 5% FS increased total biogas and methane production up to 10.4~22.7% and 17.4~27.5%, respectively, compared to other groups (p<0.05). Total solid (TS) digestion efficiency showed a similar trend to the total biogas and methane productions. Generally the TS digestion efficiency of the FS group was higher than that of other groups showing at the highest value of 64.2% in the 5% FS group. Volatile solid (VS) digestion efficiencies of 68.4 and 71.0% in the 5% FS and the 5% RF were higher than other groups. After incubation, pH values in all treatment groups were over 6.4 indicating that methanogensis was not inhibited during the incubation. In conclusion, the results indicated that the hydrolysis stage for methane production in anaerobic batch reactors was the late-limiting stage compared with the methanogenesis stage, and especially, as the supplementation levels of F. succinogenes supplementation increased, the methane production was increased in the BMP assay compared with other microbial culture addition.

• Journal of agriculture & life science
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• v.45 no.3
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• pp.69-79
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• 2011

This study was conducted to estimate effects of by-products of medical herbs replacing rice straw on in vitro fermentation characteristics. Each trial was composed of five treatments including medical herbs : rice straw (%) = 20 : 80 (T1), 40 : 60 (T2), 50 : 50 (T3), 100 : 0 (T4) and the control. Each treatment had eight fermentation times (3, 6, 9, 12, 24, 36, 48 and 72 hours) with three replications. The gas production and DM degradation were significantly (P<0.05) increased by supplementation, especially T4, during the whole fermentation periods. Methane production increased along with addition of by-products similar to the gas production and DM degradation. The pH values ranged from 5.39 to 6.80 and were significantly (P<0.05) decreased by supplementation of by-products of medical herbs. Microbial growth rates reached the peak at between 36 and 48h, thereafter tended to decrease. Although there were no significant differences in the enzyme activities, there was a tendency of increase in T4 treatment. From above results, the replacement levels, particularly 100% replacement of rice straw by by-products of medical herbs, resulted in improving the in vitro fermentation characteristics such as increasing gas production, microbial growth and DM degradation. Also it may help digestion by increasing enzyme activities.

• Journal of the Korea Organic Resources Recycling Association
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• v.31 no.1
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• pp.15-26
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• 2023

Methane production by anaerobic digestion occurs through interspecies electron transfer (DIET), a synthetic metabolism between acetic and methanate bacteria through hydrolysis and acid production steps. In this study, to improve methane yield, the effect of addition of magnetite (Fe₃O₄), a conductor promoting DIET on methane production in food wastewater was investigated, and the effect on methane yield was assessed by methane potential (B_u) and maximum methane production rate [R_m(t₀)] by the operation of batch type anaerobic reactor adding Fe₃O₄. The B_u and R_m(t₀) of food wastewater without Fe₃O₄ were 0.496 Nm³/kg-VSadded and 38.24 mL/day, respectively. The t0 which reached to R_m appeared at 21.06 days during the operation of the anaerobic reactor. The B_u of food wastewater with Fe₃O₄ was 0.502, 0.498, 0.512, 0.510, 0.518, 0.523, 0.524, 0.540, and 0.549 Nm³/kg-VSadded in the treatment of 5, 10, 15, 20, 25, 30, 40, 70, and 100mM-Fe₃O₄, respectively, and the B_u significantly increased to 36.95% with the addition of magnetite in the addition of 15mM-Fe₃O₄. And, the addition of Fe₃O₄ shortened the duration to reach R_m from 21.06 days to the maximum of 14.67 days by the addition of Fe₃O₄. Therefore, the methane yield and production rate of food wastewater significantly improved with the addition of Fe₃O₄.

• Korean Journal of Environmental Agriculture
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• v.21 no.4
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• pp.248-254
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• 2002

This study was carried out to evaluate the proper application amount of anaerobic digestion waste water and the environmental influence on rice. The waste water collected after methane fermentation process of pig manure was used as a liquid manure. Liquid manure 100%+chemical fertilizer 30%(LM 100%+CF 30) treatment was the most favorable at all growth stages of rice. The LM 100%+CF 30% treatment was applied to 100% amount of liquid manure which was correspond to the same amount of nitrogen for the standard application amount on rice, with adding 30% amount of chemical fertilizer(urea) at tillering stage. The yields of rice in the treatments of 100%(LM 100%) and 150% amount(LM 150%) of liquid manure were similar or a little higher than NPK treatment but LM 100%+CF 30% treatment was less than the NPK treatment due to the increase of straw weight and plant lodging. In periodic changes of the $NH_4-N$ and $NO_3-N$ contents, the LM 70%+CF 30% treatment in paddy soil was the highest in all treatments. The NPK and the LM 100% treatments in irrigation water quality were higher than other treatments. In infiltration water quality, $NH_4-N$ content was leached out much in the LM 150% treatment and $NO_3-N$ content was in the LM 100%+CF 30% treatment. The proper application amount of anaerobic digestion waste water as a liquid manure must be to analyse the nitrogen content of the waste water and to apply the same amount of nitrogen for the standard application amount on rice.