• Proceedings of the Korean Society for Applied Microbiology Conference
• /
• 1975.07a
• /
• pp.111.4-111
• /
• 1975

1l들이 mass cylinder에 200ml의 맥주를 넣고 질소가스로써 발포시킨 다음 거품이 사라지는 현상을 시간적으로 측정하는 방법을 이용하며 생산공정의 각 단계에서 채취한 맥주를 검사해 본 결과 chillproofing 공정 이후의 맥주에 foaming이 현저히 손상되고 있다는 것을 알았다.

• Environmental engineer
• /
• v.18 s.190
• /
• pp.73-75
• /
• 2002

우리 환경인들의 삶의 터전인 현장에는 많은 유해$\cdot$위험요인들이 상존하고 있으나 이를 간과하거나 무시하고 지나쳐버림으로써 돌이킬 수 없는 중대재해가 빈번히 발생하고 있습니다. 이에 본지는 최근 발생된 환경오염방지시설 또는 생산공정 현장에서의 재해사례를 알려드림으로써 발생가능한 재해를 사전예방하고 회원 여러분들의 소중한 생명을 보호코자 합니다.

• Environmental engineer
• /
• v.19 s.206
• /
• pp.74-75
• /
• 2003

우리 환경인들의 삶의 터전인 현장에는 많은 유해$\cdot$위험요인들이 상존하고 있으나 이를 간과하거나 무시하고 지나쳐버림으로써 돌이킬 수 없는 중대재해가 빈번히 발생하고 있습니다. 이에 본지는 최근 발생된 환경오염방지시설관련 재해사례를 알려드림으로써 발생가능한 재해를 사전예방하고 회원 여러분들의 소중한 생명을 보호코자 합니다.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.41 no.8
• /
• pp.632-638
• /
• 2013

This paper describes on the flame stability and combustion instability of coal derived synthetic gas especially for gases of Buggenum IGCC in Netherlands and Taean IGCC in Korea. These combustion characteristics were observed by conducting ambient-pressure elevated-temperature combustion tests in GE7EA model combustor when varying heat input and nitrogen dilution ratio. Flame stability map is plotted according to the flame structure by dividing all regimes into six, and only regime I and II are identified to be stable. Both syngases of Taean and Buggenum with nitrogen integration corresponds to regime II in which syngas burnt stably and flame coupled with outer recirculation flow. Stable regime of Buggenum is larger than that of Taean when considering only $H_2$/CO ratio due to higher content of hydrogen. However, when considering nitrogen dilution, syngas of Taean is burnt more stably than that of Buggenum since more nitrogen in Buggenum has negative effect on the stability of flame.

• Proceedings of the KAIS Fall Conference
• /
• 2009.05a
• /
• pp.543-545
• /
• 2009

유럽을 포함한 많은 선진국들은 자동차 배기가스에 대한 환경규제를 만족하기 위해서 노력을 하고 있다. 가솔린 엔진에 비해서 문제가 되는 디젤엔진에서 배출되는 배기가스 즉 질소 산화물과 입자상 물질을 저감하려는 노력은 꾸준히 진행되고 있다. 본 논문은 11,000cc 대형 터보 디젤엔진에 배기가스 순환장치를 설치하여 질소산화물을 효과적으로 저감하는 기술을 개발하고자한다.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2016.02a
• /
• pp.166.2-166.2
• /
• 2016

최근 생산 장비의 발달로 인해 절삭공구, 전기전자 부품, 항공 및 자동차 부품 생산에 필요한 생산 장비의 수명연장, 고속 절단 및 고성능화가 중요시 되면서 우수한 내구성, 내마모성 및 고온 안정성을 갖는 기계부품 및 공구를 요구하게 되었다. 내마모성을 가지는 표면을 얻기 위해서는 TiN, TiC, AlN, Al2O3, CrN, ZrO2와 같은 경도 높은 물질을 증착하여 특성을 개선시키는 방법이 있다. 특히 AlN은 비교적 우수한 경도와 고온 안정성을 가지고 있어, 생산 장비의 고속 절단 및 반복되는 정밀 작업으로 인한 열충격과 마모를 완화시키는 역할을 하는 코팅재로 사용하기 적합하다. 본 실험에서는 RF-magnetron sputtering 방법을 이용하여 AlN 박막을 파워 150W, 질소가스 분압비에 따라 25%, 50%, 75%, 100%의 조건으로 금속기판 위에 증착하였다. 금속 기판 위에 제작된 AlN막은 XRD (X-ray Diffraction)을 사용하여 배향성을 확인하였고, HM-220 (Micro-vickers hardness tester)을 사용하여 AlN박막의 경도를 측정하였으며, SEM (Scanning Electron Microscope), AFM (Atomic Force Microscope)을 이용하여 표면의 구조와 거칠기를 측정하였다. 이 실험을 통하여 우수한 물성과, 치밀한 조직의 AlN박막이 고속 절삭 공구, 유공압 실린더, 베어링과 같은 금속부품의 코팅소재로 적용가능 할 것으로 기대된다.

• Korean Journal of Food Science and Technology
• /
• v.19 no.3
• /
• pp.195-199
• /
• 1987

Changes in quality characteristics of boiled-dried anchovy during storage under different packaging conditions for 6 months were studied. For the packaging trials, kraft paper (KP), kraft paper laminated with 0.03 mm polyethylene film (KP/PE) and 0.1 mm polyethylene film with nitrogen gas substitution ($N_2$ gas) were employed. In case of KP, the reaction of thiobarbituric acid, browning rate of lipid oxidation and Hunter color values of L, a and b were remarkably higher than those packaged in KP/PE or $N_2$ gas. Judging from organoleptic evaluation boiled-dried anchovy could be preserved in acceptable condition for 6 months at $5^{\circ}C$in all packaging cases and, at room temperature, 3 months in KP and 4 months in KP/PE or $N_2$ gas. From the standpoint of quality stability by packaging methods, it was concluded as good in sequence as $N_2$, gas, KP/PE and KP. The results suggest that the quality of boiled-dried anchovy be well preserved by packaging with inert gas ($N_2$ gas) or impermeable material to vapors and oxygens.

• Korean Journal of Poultry Science
• /
• v.34 no.4
• /
• pp.287-294
• /
• 2007

Current study was conducted to identify the effects of dietary supplementation of Aspergillus oryzae ferments (AOF) cultured under normal (NAOF) or nitrogen-deficient (NMAOF) environment on feed efficiency, nutrient digestibility for broiler chicks. Fecal microbes and ammonia gas production were also determined. A total of 168 male Avian chicks, 2-wk-old, were randomly assigned into 56 cages, three chicks per cage. There were seven treatments (Control, NAOF 0.05, 0.1, 0.5%, NMAOF 0.05, 0.1, 0.5%), with 8 replicates (cages) per treatment. There was no significant difference in nutrient digestibility between two AOF groups, but the digestibility was greatly(p<0.05) improved by AOF supplementation. Total microbial account significantly (p<0.05) differed between the treatment groups with the highest number for NNAOF, followed by NAOF and control. In the case of Escherichia coli and Salmonella, the AOF supplementation significantly (p<0.05) reduced their numbers in feces, with a particular reduction in NNAOF group. Levels of ammonia gas generation were in order of control>NAOP>NNAOP. The current data implied that AOF supplementation, particularly grown under nitrogen-deficient environment, would be a feasible way to improve feed efficiency for broiler production, as well as to reduce environmental cost. However, further studies remain for industrial application.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.35 no.8
• /
• pp.789-798
• /
• 2011

We carry out an experimental investigation to analyze the basic performance of NO(nitric oxide) storage in a lean phase and also analyze the NO reduction achieved by the spraying of reducing agents in the rich phase of the exhaust gas in an LNT(Lean NOx Trap). This is an after-treatment system used to reduce the NOx emissions from a diesel engine. If the stored NO is reduced, we measure the outlet concentration downstream of the LNT. The test LNT material used in the experiments is commercial LNT. After being canned into stainless-steel(SUS304), it was built in a micro bench-flow reactor. Compositions of feed gases, three heated and three no heated gases were sprayed upstream of the LNT to analyze the characteristics. We use various temperatures and space velocities as response variables.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.32 no.1
• /
• pp.49-59
• /
• 2024

Biodegradable coating urea plays an important role in reducing the non-pollutants in agroecosystems, maximizing the plant nutrient utilization efficiency and slow-releasing nitrogen. Herein, the objective of this study was to investigate the nitrogen-releasing patterns and greenhouse gas emissions on different biodegradable coating urea. The treatments consisted of the control as an application of chemical fertilizers, NBCF as the non-biodegradable coating urea, NB60, and MDS as biodegradable coating urea. As a result of this study, the maximum accumulated total nitrogen (TN) concentration in the NBCF was higher at 33% than one in the NB60 during the precipitation periods. Its leaching period in the NCBF was prolonged for day 10 compared to the NB60. TN and NO₃-N releasing patterns in the NBCF and NB60 were fitted well on linear types(R²≥0.991), but their control and MDS were fitted well on Sigmoid curves(R²≥0.994) with high releasing concentration in the MDS compared to the control during leaching periods. For the greenhouse gas emissions, CH₄ emissions in the NBCF, NB60, and MDS were increased at 0.38%, 11.36%, and 5.91%, and N₂O emissions were also increased at 50.5%, 32.4%, 58.8% as compared to the control, respectively. Therefore, application of biodegradable polymer coating urea might mitigate the non-point pollutants in agro-ecosystem.