• 한국환경보건학회지
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• 제26권3호
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• pp.98-102
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• 2000

The aim of this study was to evaluate on the removal effect of total nitrogen in municipal wastewater by decreasing hydraulic retention time(HRT) from 6 hour to 4 hour on CNR process. CNR-A(Cilia Nutrient Removal) is the process combining A2/O process with cilium media of H2L corporation. The removal efficiencies for T-N were 63.1% in A-1 reactor, and 73.5% in A-2 reactor and 77.0% in A-3 reactor. The specific nitrification(g-NH3-N/g-MLVSS.d) of Oxic in CNR-A process was 0.07-0.32. The specific denitrification in Anoxic and the specific nitrification inOxic was higher in HRT 4 hour because of optimum F/M ratio.

• 한국연소학회지
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• 제15권1호
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• pp.38-42
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• 2010

Using a counterflow burner, downstream interactions between $CH_4$-air and $H_2/N_2$-Air premixed flames with various equivalence ratios has been experimentally investigated. Flame stability maps on triple and twin flames are provided in terms of global strain rate and equivalence ratio. Lean and rich flammable limits are examined for methane/air and hydrogen/nitrogen/air mixtures over the entire range of mixture concentrations in the interacting flames. Results show that these flammable limits can be significantly modified in the presence of interaction such that mixture conditions beyond the flammability limit can be still burn if it is supported by stronger flame. The experiment also discusses various oscillatory instabilities in a stability map.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1993년도 추계학술대회 논문집
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• pp.97-102
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• 1993

According as the high integrity of the semi conductor devices is definited required, the concern on the multi-layered wiring, and three-dimensional devices is growing these days. Therefore, plasma-enhanced chemical vapored deposition(PECVD) enables low-teperature process and is widely used, but it causes the instability of the devices due to a lot of impurities within the film. The PECVD oxynitride was formed by changing the gas ratio of (N$_2$O) to (N$_2$+NH$_3$). It's contained a small portion of hydrogen, had higher refrctive index and capacitance than oxide, and showed the capacitance increasement and the chemical stabi1ity. This is caused by nitrogen distribution increase of the interface lather than within the film.

• 한국환경보건학회:학술대회논문집
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• 한국환경보건학회 2002년도 춘계 국제 학술대회
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• pp.84-90
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• 2002

In 1995 we licensed pyrolysis gas melting technology of indirect heating type (using kiln) from Siemens AG, and built its demonstration facility in 1998 at Clean-Park-East of Fukuoka City to demonstrate the technology for municipal solid waste (MSW). In 1997 we were awarded an order from Kanemura Co., Ltd. to build a pyrolysis gas melting and power generation plant, specifically for treating residue from car shredder. The latter was launched in 1998, and is currently in commercial operation. The operation of these plants have proven the following facts. (1) The system is capable for performing a stable operation with a wide variety of waste. (2) Pyrolysis is achieved steadily regardless of the variation in the quality of waste. (3) The system can be operated under low excess air ratio (1.2∼1.3). (4) The concentration of dioxins at the furnace outlet is 0.062ng-TEQ/㎥$\_$N/, and 0.002ng-TEQ/㎥$\_$N/, at the stack. (the value is corrected to dryO$_2$ 12％) (5) The purity of recovered metals exceeds 90%.

• 대한기계학회논문집B
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• 제21권12호
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• pp.1615-1623
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• 1997

Numerical study on the chaotic stirring of the screw extruder model proposed has been performed. The velocity field was used in obtaining the trajectories of passive particles for studying the stirring effect of the screw extruder. Two nonlinear dynamical tools, that are Poincare sections and Lyapunov exponents, were used in analysing the stirring effect. The Poincare sections and the Lyapunov exponents show that the stirring effect is most satisfactory, when n(the number of flights in a section) is 1, for the case a (aspect ratio ; flight height divided by the spacing between flights) being O.1. It is also required to set n=3, or 5 at a= 0.2, 0.3 for a uniform stirring.

• Corrosion Science and Technology
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• 제17권6호
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• pp.265-271
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• 2018

CRUD specimens, scraped from twice-burned fuel cladding in the Korean Nuclear Power Plant, were analyzed using Shielded-EPMA. The principal elements of the CRUD were identified as Ni and Fe, at an approximate ratio of 1.3 Ni/Fe. To investigate the morphology and composition of the pure metallic materials in the CRUD, coolant impurities must be removed. This can be accomplished by increasing the EPMA current to an abnormally high intensity until the impurities are melted. Normally, EPMA applications are performed at conditions of 20 kV voltage and 20 nA current. But in our study, the applied current was increased up to 1200 nA, over time increments ranging from 5 to 30 seconds. This technique was performed by opening an adjustable aperture for the gun alignment. Results showed impurities contained in the CRUD material disappeared and pure metal materials, e.g., Ni and Fe, remained. This method presents an innovative way to analyze CRUD.

• Nuclear Engineering and Technology
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• 제53권8호
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• pp.2564-2569
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• 2021

The neutronic analysis of Helium Cooled Ceramic Reflector (HCCR) breeding blankets has been performed using the 3D Monte Carlo code MCNPX and ENDF nuclear data library. This study aims to reduce ⁶Li percentage in the breeder zones as much as possible ensuring tritium self-sufficiency. This work is devoted to investigating the effect of ⁶Li percentage on the HCCR breeding blanket's neutronic parameters, such as neutron flux and spectrum, Tritium Breeding Ratio (TBR), nuclear power density, and energy multiplication factor. In the ceramic breeders at the saturated thickness, increasing the enrichment of ⁶Li reduces its share in the tritium production. Therefore, ceramic breeders typically use lower enriched Li from 30% to 60%. The investigation of neutronic analysis in the suggested geometry shows that using 60% ⁶Li in Li₂TiO₃ can yield acceptable TBR and energy deposition results, which would be economically feasible.

• 대한화학회지
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• 제32권6호
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• pp.536-542
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• 1988

새로 합성한 N-benzylisonitrosoacetylacetone imine(CH3-CO-CNOH-CNCH2${\phi}$-CH3, 이하 H-IAA-NBz)을 리간드로 하는 Nickel(Ⅱ) 착물을 합성하고, 원소분석, 적외선흡수스펙트럼, 핵자기공명스펙트럼, 전자스펙트럼 및 질량스펙트럼등 분광학적인 자료와 자기모멘트 측정으로부터 구조를 구명하였다. 이 착물은 상온에서 매우 안정하며, cis-형 및 trans-형의 기하이성질체가 존재한다. Nickel 이온과 리간드로 1 : 2로 결합한다. 결합된 두 리간드 중 한쪽 리간드는 isonitroso기의 질소원자와 이민의 질소원자가 Nickel(Ⅱ) 이온과 결합하여 5원고리를, 다른쪽 리간드는 isoniroso기의 산소원자와 이민의 질소원자가 Nickel(Ⅱ)이온과 결합하여 6원고리를 형성하여 4각평면구조를 만들고 있다.

• 한국수소및신에너지학회논문집
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• 제21권5호
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• pp.412-418
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• 2010

Steam reforming of n-hexadecane, a major component of diesel over Ni-based hydrotalcite-like catalyst was carried out at $900^{\circ}C$ at atmospheric pressure with space velocity of $10,000h^{-1}$ and feed molar ratio of steam/carbon=3.0. Ni-based hydrotalcite catalyst was prepared by a solid phase crystallization (spc) method and characterized by $N_2$-physisorption, CO chemisorption, TPR., XRD, and TEM techniques. It was found that spc Ni/MgAl catalyst showed higher catalytic stability and inhibition of carbon formation than Ni/$\gamma-Al_2O_3$ catalyst under the tested conditions. The results suggest that the modified spc-Ni/MgAl catalyst after optimization may be applied for the SR reaction of diesel.

• Journal of Animal Science and Technology
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• 제65권4호
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• pp.818-837
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• 2023

Understanding adipocyte development in fetus during bovine pregnancy is important for strengthening fattening technology. Additionally, nutritional level of dams during pregnancy has the potential to improve offspring growth and fat development. The purpose of this study is to evaluate the intramuscular adipocyte development and expression level of related genes in bovine fetus, and the effect of increased crude protein (CP) intake during pregnancy on the growth performance and carcass characteristics of male offspring. Eighty six pregnant Hanwoo cows (average body weight, 551.5 ± 51.3 kg, age 5.29 ± 0.61 y) were used. Fetuses were collected at 90, 180 and 270 d of gestation from 18 pregnant Hanwoo cows. The remaining 68 pregnant cows were randomly assigned to 2 feeding groups. The control (CON) group was provided the standard protein diet (n = 34), and treatment (TRT) group was provided a diet with a 5% increase in CP intake (n = 34). Male offspring were divided into two groups according to protein treatment of the pregnant cows: CON male offspring (CON-O) and TRT male offspring (TRT-O). Intramuscular adipocytes were found in the fetal skeletal muscle after 180 days of gestation. Male calf's birth weight increased in the TRT group compared to that in the CON group (p < 0.002). The final body weight (p < 0.003) and average daily gain (p < 0.019) of male offspring were significantly higher in TRT-O than in CON-O. The feed conversion ratio was also improved by 10.5% in TRT-O compared to that in CON-O (p < 0.026). Carcass weight was significantly higher in the TRT-O group than that in the CON-O group (p < 0.003), and back fat was thicker in the TRT-O group (p = 0.07). The gross receipts and net income were higher in TRT-O than in CON-O (p < 0.04). Thus, fetal intramuscular fat can be formed from the mid-gestation period, and increased CP intake during pregnancy can increase net income by improving the growth and carcass weight of male offspring rather than intramuscular fat.