• 열처리공학회지
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• 제34권6호
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• pp.272-280
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• 2021

The influence of acetylene flow rates on the carburizing behavior of an AISI 4115 steel in 1 ton-class mass production-type vacuum carburizing furnace has been studied through microstructure, carbon concentration, hardness analyses. The AISI 4115 steels were carburized with various flow rates (20, 32.7, 60 l/min) and locations in the furnace (top, center, bottom) at 950℃. The acetylene flow rate played an important role in controlling the carburizing properties of carburized samples, such as effective case depth and uniformity carburizing according to location in the furnace. At an acetylene flow rate of 20 l/min, the carburized samples had a shallow average hardened layer (0.645 mm) compared to the target hardening depth (1 mm) due to low carbon flux and spatial uniformity of carburization (17.8%) in the furnace. At a flow rate of 60 l/min, the carburized samples showed an average hardened layer (1.449 mm) deeper than the target hardening depth and had the spatial uniformity of carburization (98.8%). In particular, at a flow rate of 32.7 l/min, the carburized samples had an average hardened layer (1.13 mm) close to the target hardening depth and had the highest carburizing uniformity (99.1%). As a result, an appropriate flow rate of 32.7 l/min was derived to satisfy the target hardening depth and to have spatial uniform hardened layer in the furnace.

• 한국안전학회지
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• 제6권2호
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• pp.31-36
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• 1991

Quenching effects of acetylene and hydrogen into oxygen detonation by using detonation arrester ［DA］are studied in this paper. The experiments were carried out in cylinderical shock tube. 5m long, 30mm dia., with stolchlometric ratio ［SR］of each gas and 10-l20$\mu$ Cell Size of brass and Stainless Steel of DAs were installed in it To clarify arresting ability correlation with initial pressure, Pi, critical thickness, Tct, and shapes of supporting panel of DA are also investigated It is found that ­detonation velocities has most dependency on Pi, it shows notable changes around 0.5kgf/$\textrm{cm}^2$ for hydrogen, 0.15kgf/$\textrm{cm}^2$ for acetylen respectively, ­DA can be safety device able to arrest shock wave of detonation, ­over Tct flame transmission might be only the factor has to be considered, ­acetylene seems to be much more stronger detonation characteristics than hydrogen because of reaction heat.

• 미생물학회지
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• 제25권2호
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• pp.129-136
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• 1987

영남작물시험장에서 질소비료 공급없이 재배합 40종의 수도품종으로부터 출수기전의 수도근권의 질소고정력을 in situacetylene 환원력 측정방법으로 시험한 결과 Azospirillum 균의 무질소 malate 배지에서 얻은 균주와 상관관계를 보였다. 이 중 질소고정력이 높은 6종의 Azospirillum을 분리 동정한 결고 5종은 A. lipoferum, 1종은 A. brasilense임을 확인한 후 이들 6종의 Azospirillum들의 당이용성, biotin 요구성, 항생제저항성, auxin 생산성, plasmid profile 및 균체단백질 pattern을 비교 분석하였다.

• 한국자동차공학회논문집
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• 제10권6호
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• pp.80-89
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• 2002

The flame structure and soot formation in Acetylene-Air nonpremixed jet flame are numerically analyzed. We employed two variable approach to investigate the soot formation and oxidation processes. The present soot reaction mechanism involves nucleation, surface growth, particle coagulation, and oxidation steps. The gas phase chemistry and the soot nucleation, surface growth reactions are coupled by assuming that the nucleation and soot mass growth has the certain relationship with the concentration of pyrene and acetylene. We also employed laminar flamelet model to calculate the thermo-chemical properties and the proper soot source terms from the information of detailed chemical kinetic model. The numerical and physical model used in this study successfully predict the essential features of the combustion processes and soot formation characteristics in the reaction flow field.

• 한국가스학회지
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• 제7권1호
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• pp.41-46
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• 2003

14atm, 233K의 아세틸렌 기체를 자유팽창 시켜서 생성한 아세틸렌 cluster의 상과 온도 변화를 실험적으로 측정하였으며, cluster를 여러 겹의 shell로 나누어 취급하고 각 shell 마다 증발과 열전도 현상에 근거한 온도계산을 하는 모델링을 적용하여 이론적인 온도를 구하고 실험값과 비교함으로써, 생성된 cluster의 크기를 4.88$\mu$으로 결정하였다.

• 센서학회지
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• 제32권1호
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• pp.55-61
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• 2023

The objective of this study is to determine the concentrations of mixed gases by establishing a diagnosis method of a transformer using tunable-wavelength optical infrared sensors. Absorption of infrared light by methane, acetylene, and ethylene gases injected is measured from the outputs of the infrared sensors. Regression analysis equations of the gas concentrations are acquired from their respective measured absorption. The obtained concentrations are as follows: -3-9 % errors above 600 ppm(methane), 3 % errors above 1200 ppm(acetylene), and 10 % errors above 500 ppm(ethylene). The concentration inference equations obtained using the individual gases are applicable when the absorption wavelength bands do not overlap. The results of the fault analysis of a transformer using the Duval triangle method and the tunable infrared gas sensors are as follows: temperature faults with -1-1% errors and energy faults with -7-7 % errors.

• Journal of Ceramic Processing Research
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• 제13권spc1호
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• pp.42-46
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• 2012

The effect of the parameters for few-layered graphene growth by thermal CVD on nickel substrate was investigated. Graphene can be synthesized by using different strategies. Chemical vapor deposition (CVD) has known as one of the most attractive methods to produce graphene due to its good film uniformity, compatibility and large scale production. The control of parameters such as temperature, growth time and pressure in CVD process has been widely recognized as the most important process in graphene growth. Different carbon precursors, methane and acetylene, were introduced in the quartz tube with a variety of growth conditions. Raman spectroscopy was used to confirm the presence of a few- or multi-layered graphene.

• 한국작물학회지
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• 제32권3호
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• pp.323-329
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• 1987

본 연구는 생태적 생리적 특성이 다른 5 콩 품종, 즉 조숙성의 예계7003. SS 79168 및 만숙성의 동북 7006. 백운콩, 장백콩을 공시하여 일본국 농업생물자원연구소 질소고정연구실 망실에서 진행하였으며, 등숙기간 중 체내성분의 영양생리학적인 관점에서 질소고정활성과의 관련성을 해명하기 위하여 Acetylene 환원능(ARA) 등 각종 조사를 실시하였다. 특히 공시품종 중 예계 7003는 노화가 지연되는 특성(delayed leaf senescence, DLS)을 갖는 품종이 다. 조사는 Fehr et al. (1977)의 콩 생육단계의 구분에 따라서 협신장기( $R_4$), 입비대기( $R_{6}$), 성숙시기( $R_{7}$) 등과 일부품종은 착협시( $R_3$) 및 $R_{4.5}$, $R_{6.5}$, $R_{7.5}$와 같은 중간적 생육단계에도 보족적인 조사를 실시하였는데, 얻어진 결과 중 질소고정활성의 경시적 변동과 각 기관 건물중과의 관계를 우선 보고하며 이를 요약하면 다음과 같다. 1. 콩의 질소고정활성을 Acetylene 환원법으로 측정한 결과 pot당 Acetylene 환원능(p-ARA)은 공시품종 모두 $R_{6}$에서 최고에 달한 후 급속히 저하하였다. 근류중당 Acetylene 환원능(s-ARA)은 조숙성 품종에서는 $R_4$~ $R_{4.5}$에서 최고에 달한 후 감소하는 경향을 보인 반면 만숙성 품종에서는 $R_{6}$까지 상승하고 기후 급속히 감소하였다. 근류중 및 숙주 각 기관의 건물중은 생육 각 단계 모두 숙기가 늦은 품종에서 커서 p-ARA도 만숙성 품종에서 높았다. 2. p-ARA와 각 기관 건물중은 모두 높은 정의 상관을 나타내었으나, 표준신회귀계수에 의한 상대적 기여도에서 보면 엽 > 근류 > 자실의 순으로 정의 효과를 나타내고, 협곡, 근, 경은 부의 효과를 나타내었다. 3. 성숙시기에 있어서 지상부 총중 및 종실중은 조숙종에서 그 Biomass가 작았으나 수확지수와 근류/지상부 총중비는 조숙종이 만숙종에 비하여 높고, 특히 DLS인 예계 7003는 타 공시품종보다 높았다.수와 근류/지상부 총중비는 조숙종이 만숙종에 비하여 높고, 특히 DLS인 예계 7003는 타 공시품종보다 높았다.

• Bulletin of the Korean Chemical Society
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• 제31권7호
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• pp.2097-2099
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• 2010

• 대한화학회지
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• 제46권6호
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• pp.595-598
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• 2002