• 한국토양비료학회지
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• 제41권2호
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• pp.137-142
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• 2008

This study was conducted to evaluate the humification grade of compost, based on physico-chemical property and phyto-toxicity during the composting with three kinds of livestock manures and saw dust. The ratios of the compost, which was mixed with pig manure(P) and sawdust(S) were 4 : 6(PS-1), 5 : 5(PS-2) and 6 : 4(PS-3); poultry manure(PO) and sawdust(S) were 4 : 6(POS-1), 5 : 5(POS-2) and 6 : 4(POS-3); cow manure(C) and sawdust(S) were 4 : 6(CS-1), 5 : 5(CS-2) and 6 : 4(CS-3) by volume to volume, and they were decomposed for 60 days. In the result, the temperature in all treatments during composting rapidly increased above $65.4^{\circ}C$, and then gradually decreased to around $40^{\circ}C$. At 60 day, after the treatment, pH 5.9 ~ 8.0 at the incipient stage increased to 7.6 ~ 8.5, and the C/N ratio was 13.8 ~ 21.1 at the final composting stage. Germination Index(G.I.) showed in the range of 75.1 ~ 94.6 in all treatments at day 60. Therefore, it is likely recommended to take the best humification grade when the temperature maintains above $65^{\circ}C$ longer than a day at minimum, in the range of pH 6.5 ~ 8.5 for the final compost, under 20 of C/N ratio, and G.I. above 80. The level of G.I. above 80 should be the mature compost which could be used in the field without gas demage to crops.

• 한국식품저장유통학회지
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• 제15권2호
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• pp.191-196
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• 2008

본 연구에서는 최소가공 단호박의 제품화를 위하여 절단 방법이 실선절단 단호박 제품의 저장 중 품질에 미치는 영향을 조사하였다. 단호박을 8 pieces, dice, slice, shredding의 4가지 방법으로 절단하여 $10^{\circ}C$에서 9일 동안 저장하면서 중량감소율, 색도 변화, 경도변화, pH, 가용성고형분, 기체조성 그리고 관능적 특성변화를 조사하였다. 호흡특성에서는 8 pieces의 $CO_2$와 $C_2H_4$ 발생량이 가장 적은 것으로 나타났다. 중량감소율과 pH에서는 8 pieces가 가장 적었으며 유의적인 차이를 볼 수 있었다. 또한 다른 처리구에 비해 넓은 표면적 때문에 증산작용이 활발한 slice, shredding 처리구의 가용성 고형분의 함량이 가장 높았다. 이러한 결과를 미루어 보아 최소가공 단호박의 저장에는 표면적이 가장 적은 8 pieces가 가장 효과적이라 생각된다.

• Korean Chemical Engineering Research
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• 제45권6호
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• pp.656-662
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• 2007

고분자 전해질 연료전지 운전에 필요한 수소 공급 장치로서 플라즈마 개질 방법을 이용한 개질기와 일산화탄소 산화반응을 위한 전이 반응기를 설계 및 제작하였다. GlidArc 방전을 이용한 저온플라즈마 개질기는 Ni 촉매를 동시에 사용하여 $CH_4$ 개질함으로서 $H_2$ 선택도를 증대하였다. 개질기의 변수별 연구로서 촉매 온도, 가스 조성비, 전체 가스유량, 전압변화 그리고 개질 특성 및 최적 수소 생산조건을 연구하였으며, 전이반응기의 변수별 연구로서 선택적 산화반응기(PrOx)에 주입되는 공기량, 전이 반응기에 주입되는 수증기량 그리고 온도에 대하여 연구하였다. 플라즈마 개질기에서 최대 수소 생산 조건은 $O_2/C$ 비가 0.64, 가스유량은 14.2 l/min, 촉매 반응기 온도 $672^{\circ}C$ 그리고 유입전력이 1.1 kJ/L일 때 41.1%로 최대 수소 농도를 나타냈다. 그리고 이때의 $CH_4$ 전환율, $H_2$ 수율 그리고 개질기 에너지 밀도는 각각 88.7%, 54%, 35.2%를 나타냈다. 전이 반응기에서 모사된 개질 가스로부터 최대 CO 전환율을 보이는 조건은 2단으로 구성된 PrOx에 주입되는 $O_2/C$ 비가 0.3, HTS에서 주입되는 수증기 주입량 비가 2.8 그리고 HTS, LTS, PrOx I, PrOx II 반응기 온도가 475, 314, 260, $235^{\circ}C$ 일때 가장 높은 CO 전환율을 나타냈다. 플라즈마를 이용한 반응기는 예열 시간은 30분이 소요되었으며, 전이 반응기에서 나오는 최종 개질 가스의 조성은 $H_2$ 38%, CO<10 ppm, $N_2$ 36%, $CO_2$ 21% 그리고 $CH_4$ 4%로 나타냈다.

• KSBB Journal
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• 제10권5호
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• pp.582-588
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• 1995

해양의 유류유출이 잦은 지역으로부터 crude oil 분해능이 뛰어난 미생물을 분리하여 통정한 결과 Pseudomoans 속으로 판명되였으며, 이를 Pseud$\sigma$ moans sp. CHCS-2로 명 명하였다. 이 균주가 배양 중에 생산하는 biosurf actant의 생생 최적 pH 및 NaCI 농도는 각각 8.0 및 3.0% 였으며, 질소원인 peptone에 영향을 받았다. 2% Kuwait crude oil이 첨가된 배양액을 48, 96, 132시간별로 gas chroma­t tography를 이용, 잔류 oil을 분석한 결과 Kuwait crude oil의 C10-CI4부위에 biosurf actant가 작용하여 분해하였으며, 배양 상층액으로부터 Amberlite XAD-7을 이용한 흡착 chromatography와 Sepha­d dex G-100을 이용한 gel chromatography, 그리고 HPLC를 이용하여 biosurf actant를 분리. 정제한 결과 유화력이 뛰어난 단일 peak를 얻었다. Bio-sur­f f actant 유화력은 $40^{\circ}C$에서 가장 좋았으며, 안정성 은 $30^{\circ}C$에서 $60^{\circ}C$까지의 넓은 온도 범위에서 유지 되었다. 또한, 정제된 biosurf actant를 이용하여 계 연장력에 미치는 영향을 검토한 결과, 상엽적으로 널리 판매되고 있는 Tween 80, Tween 60 그리고 SDS보다 표연장력 저하능력이 뛰어난 것으로 밝혀졌다.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2004년도 Proceedings of the 4th Korea-China Joint Workshop on Nuclear Waste Management
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• pp.238-244
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• 2004

The relationship between the leaching and gap inventory of spent fuel has been studied. When a specimen of J44H08 spent PWR fuel with 38 GWD/MTU has been leached in the synthetic granitic groundwater in Ar atmosphere, the released fraction of cesium was increased rapidly up to 0.7% at around 500 days and stayed below 0.8% until 3 years. This 0.7% of cesium might be released from the gap in this fuel. The measurement of gap inventory with C15I08 spent PWR fuel, having 35 GWD/MTU and 0.22% of fission gas release, was also determined near 0.6% for the cesium, which is a similar fraction of cesium released from the leaching experiment with J44H08 fuel. Its gap inventories of strontium and iodine were about 0.03 and less than 0.2% respectively. Respective fractions of cesium and strontium in grain boundary of C15I08 were 0.78, 0.09%.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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• pp.459-459
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• 2012

Recently, the discharge of global warming gases in dry etching process of TFT-LCD display industry is a serious issue because perfluorocarbon compound (PFC) gas causes global warming effects. PFCs including CF4, C2F6, C3F8, CHF3, NF3 and SF6 are widely used as etching and cleaning gases. In particular, the SF6 gas is chemically stable compounds. However, these gases have large global warming potential (GWP100 = 24,900) and lifetime (3,200). In this work, we chose C3F6O gas which has a very low GWP (GWP100 = <100) and lifetime (< 1) as a replacement gas. This study investigated the effects of the gas flow ratio of C3F6O/O2 and process pressure in dual-frequency capacitively coupled plasma (CCP) etcher on global warming effects. Also, we compared global warming effects of C3F6O gas with those of SF6 gas during dry etching of a patterned positive type photo-resist/silicon nitride/glass substrate. The etch rate measurements and emission of by-products were analyzed by scanning electron Microscopy (SEM; HITACI, S-3500H) and Fourier transform infrared spectroscopy (FT-IR; MIDAC, I2000), respectively. Calculation of MMTCE (million metric ton carbon equivalents) based on the emitted by-products were performed during etching by controlling various process parameters. The evaluation procedure and results will be discussed in detail.

• 농업과학연구
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• 제26권2호
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• pp.25-32
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• 1999

본 시험음 활성탄의 첨가가 사료의 반추위내 발효성상 건물 및 영양소 소실율 반추위내 가스 생산량에 미치는 영향을 조사하기 위하여 in vitro 조건에서 실시되었다. 활성탄의 첨가수준은 0.00 0.25 0.50 %의 3수준이었으며, 사료의 조농비율은 볏짚과 농후사료 비율을 8:2 6:4 4:6 및 2:8로 하였다. 그리고 처리간 유의성은 5% 수준에서 검정하였다. 시험 결과를 요약하면, 위액의 pH는 활성탄의 첨가 비율이 높아질수록 높아지는 경향을 나타냈으나 유의성은 인정되지 않았으며, 사료의 조농비율에 따른 영향은 8:2구가 다른 처리구보다 유의하게 높았다. 그리고 VFA molar %는 활성탄 첨가에 의하여 유의한 결과는 아니지만 $C_2$는 감소되고 $C_3$는 증가되는 경향을 나타냈다. 또한 조사료비율이 증가될 수록 전술의 결과와는 상반된 현상을 보였다. $C_2/C_3$ 비율도 활성탄의 첨가와 농후사료 비율의 증가에 의하여 감소되는 경향을 나타냈다. 건물 및 영양소 소실율에 있어서는 활성탄 첨가에 의하여 건물 조단백질 NDF ADF hemicellulose의 소실율이 증가하는 경향을 보였다. 그러나 조지방의 소실율은 일정한 경향을 나타내지 않았다. 조농비율에 의한 영향에 있어서는 농후사료의 비율이 증가할 수록 건물 및 영양소의 소실율이 유의하게 증가하였다. 그리고 반추위내 가스 생산량에 있어서는 활성탄 0.5% 첨가구가 0.25% 및 0.00%구에 비하여 감소하는 경향이었고, 조사료의 비율이 높을수록 많아지는 경향이었다. 위 결과에서 보듯이 활성탄은 가축의 생산성 향상에 유리한 조건을 제공하는 경향이 있지만, 이것을 좀 더 명확히 밝히기 위해서는 활성탄의 흡착능력 위내의 세균총에 대한 연구 및 많은 생체실험도 병행되어야 할 것으로 생각된다.

• 천문학회보
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• 제45권1호
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• pp.43.2-44
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• 2020

We have carried out high-resolution near-infrared (NIR) spectroscopic observations toward 16 Galactic supernova remnants (SNRs) showing strong H2 emission features. A dozen bright H2 emission lines are clearly detected for individual SNRs, and we have measured their central velocities, line widths, and fluxes. For all SNRs except one (G9.9-0.8), the H2 line ratios are well consistent with that of thermal excitation at T~2000 K and their line widths are broader than ~10 km s-1, indicating that the H2 emission lines are most likely from shock-excited gas and therefore that they are physically associated with the remnants. The kinematic distances to the 15 SNRs are derived from the central velocities of the H2 lines using a Galactic rotation model. We derive for the first time the kinematic distances to four SNRs: G13.5-0.2, G16.0-0.5, G32.1-0.9, G33.2-0.6. Among the rest 11 SNRs, the central velocities of the H2 emission lines for six SNRs are well consistent (±5 km s-1) with those obtained in previous radio observations, while for the other five SNRs (G18.1-0.1, G18.9-1.1, Kes 69, 3C 396, W49B), they are significantly different. We discuss the velocity discrepancies in these five SNRs. In G9.9-0.8, the H2 emission shows non-thermal line ratios and very narrow line width (~4 km s-1), and we discuss its origin.

• Asian-Australasian Journal of Animal Sciences
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• 제25권6호
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• pp.806-811
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• 2012

This study was conducted to evaluate effects of plant extracts on methanogenesis and rumen microbial diversity in in vitro. Plant extracts (Artemisia princeps var. Orientalis; Wormwood, Allium sativum for. Pekinense; Garlic, Allium cepa; Onion, Zingiber officinale; Ginger, Citrus unshiu; Mandarin orange, Lonicera japonica; Honeysuckle) were obtained from the Plant Extract Bank at Korea Research Institute of Bioscience and Biotechnology. The rumen fluid was collected before morning feeding from a fistulated Holstein cow fed timothy and commercial concentrate (TDN; 73.5%, crude protein; 19%, crude fat; 3%, crude fiber; 12%, crude ash; 10%, Ca; 0.8%, P; 1.2%) in the ratio of 3 to 2. The 30 ml of mixture, comprising McDougall buffer and rumen liquor in the ratio of 4 to 1, was dispensed anaerobically into serum bottles containing 0.3 g of timothy substrate and plant extracts (1% of total volume, respectively) filled with $O_2$-free $N_2$ gas and capped with a rubber stopper. The serum bottles were held in a shaking incubator at $39^{\circ}C$ for 24 h. Total gas production in all plant extracts was higher (p<0.05) than that of the control, and total gas production of ginger extract was highest (p<0.05). The methane emission was highest (p<0.05) at control, but lowest (p<0.05) at garlic extract which was reduced to about 20% of methane emission (40.2 vs 32.5 ml/g DM). Other plant extracts also resulted in a decrease in methane emissions (wormwood; 8%, onion; 16%, ginger; 16.7%, mandarin orange; 12%, honeysuckle; 12.2%). Total VFAs concentration and pH were not influenced by the addition of plant extracts. Acetate to propionate ratios from garlic and ginger extracts addition samples were lower (p<0.05, 3.36 and 3.38 vs 3.53) than that of the control. Real-time PCR indicted that the ciliate-associated methanogen population in all added plant extracts decreased more than that of the control, while the fibrolytic bacteria population increased. In particular, the F. succinogens community in added wormwood, garlic, mandarin orange and honeysuckle extracts increased more than that of the others. The addition of onion extract increased R. albus diversity, while other extracts did not influence the R. albus community. The R. flavefaciens population in added wormwood and garlic extracts decreased, while other extracts increased its abundance compared to the control. In conclusion, the results indicated that the plant extracts used in the experiment could be promising feed additives to decrease methane gas emission from ruminant animals while improving ruminal fermentation.

• 열처리공학회지
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• 제5권4호
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• pp.195-200
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• 1992

SCM 415 has been vacuum carburized in the carburizing pressure of 60-65kpa and the carburizing temperature of 1233k and 1273k after varied to 0-20 in the ratio of $N_2/C_3H_8$ and then diffusion treated for various times at 1123k. The results obtained from the experiment are as follows. 1. With increasing from 0 to 20 in ratio of $N_2/C_3H_8$ the sooting formation of surface after carburizing considerably decreased. 2. The hardness control and surface carbon content of carburizing surface has been modified by the addition of nitrogen to the propan. 3. The appoximate value of k is indirectry calculated at 1123k which results are obtained to $0.58{\times}10^{-2}(wt.%.S^{-1/2})$. 4. A great deal of propan by addition of nitrogen gas in carburizing gas was possible to saving without considerable change in case hardening depth. 5. The effective carburizing depth range is obtained to 0.8-1.1mm by diffusion temperature of 1123k after carburization at 1273k-3.6ks, and the surface hardness is increased as the increasing of $T_D/T_c$ in our experimental condition, and the maximum hardness as reachin distance from surface is decreased.