NMO을 이용한 Dioxin 산화제거반응 연구

홍성창 京機大學校 2006 論文集 Vol.50 No.-

The application study for oxidation of Dioxin has been performed by NMO complex catalyst showing high activity and oxidation potential obtained from the development of low temperature SCR DeNOx catalysts. NMO catalyst by drying was shown 3% more removal efficiency through oxidation than that of NMO catalyst obtained by heat treatment at 400°C. The high conversion of 95% could be obtained for Mn+3 of NMO catalyst. The prepared NMO catalyst was affected seriously by SO_(2) content regarding to the treatment of 1,2-DCB flue gas.

신개발 심층시비장치를 이용한 심층시비의 밭작물 재배 효과

홍성창,김민욱,김진호,박성직 한국환경농학회 2023 한국환경농학회지 Vol.42 No.1

Nitrogen fertilizers applied to agricultural lands for crop cultivation can be volatilized as ammonia. The released ammonia can catalyze the formation of ultrafine dust (particulate matter, PM2.5), classified as a short-lived cli-mate change pollutant, in the atmosphere. Currently, one of the prominent methods for fertilizer application in agri-cultural lands is soil surface application, which comprises spraying the fertilizers onto the soil surface, followed by mixing the fertilizers with the soil. Owing to the low nitro-gen absorption rate of crops, when nitrogen fertilizers are applied in this manner, they can be lost from land surfaces through volatilization. Therefore, investigating a new fer-tilization method to reduce ammonia emissions and in-crease the fertilizer utilization efficiency of crops is nece- ssary. In this study, to develop a method for reducing am-monia emissions from nitrogen fertilizers applied to soil surfaces, deep fertilization was conducted using a newly developed deep fertilization device, and ammonia emis-sions from barley, garlic, and onion fields were examined. Conventional fertilization (surface application) and deep fertilization (soil depth of 25 cm) were conducted for analysis. The fertilization rate was 100% of the standard fertilization rate used for barley, and deep fertilization of N, P, and K fertilizers was implemented. Ammonia emis-sions were collected using a wind tunnel chamber, and quantified subsequently susing the indole-phenol blue method. Ammonia emissions released from the basal fer-tilizer application persisted for approximately 58 d, begin-ning from approximately 3 d after fertilization in conven-tional treatments; however, ammonia was not released from deep fertilization. Moreover, barley, garlic, and on-ion yields were higher in the deep fertilization treatment than in the conventional fertilization treatment. In con-clusion, a new fertilization method was identified as an al-ternative to the current approach of spraying fertilizers on the soil surface. This new method, which involves inject-ing nitrogen fertilizers at a soil depth of 25 cm, has the po-tential to reduce ammonia emissions and increase the yields of barley, garlic, and onion. .

신개발 심층시비장치를 이용한 심층시비가 벼와 콩 수량에 미치는 영향

홍성창,김민욱,김진호 한국환경농학회 2023 한국환경농학회지 Vol.42 No.1

Nitrogen fertilizer is an essential macronutrient that re-quires repeated input for crop cultivation. Excessive use of nitrogen fertilizers can adversely affect the environ-ment by discharging NH3, NO, and N2O into the air and leaching into surrounding water systems through rainfall runoff. Therefore, it is necessary to develop a technology that reduces the amount of nitrogen fertilizer used without compromising crop yields. Fertilizer deep placement could be a technology employed to increase the efficiency of ni-trogen fertilizer use. In this study, a deep fertilization de-vice that can be coupled to a tractor and used to inject fer-tilizer into the soil was developed. The deep fertilization device consisted of a tractor attachment part, fertilizer amount control and supply part, and an underground fer-tilizer input part. The fertilization depth was designed to be adjustable from the soil surface down to a depth of 40 cm in the soil. This device injected fertilizer at a speed of 2,000 m2/hr to a depth of 25 to 30 cm through an under-ground fertilizer injection pipe while being attached to and towed by a 62-horsepower agricultural tractor. Furthermore, it had no difficulty in employing various fertil-izers currently utilized in agricultural fields, and it oper-ated well. It could also perform fertilization and plowing work, thereby further simplifying agricultural labor. In this study, a newly developed device was used to inves-tigate the effects of deep fertilizer placement (FDP) com-pared to those with urea surface broadcasting, in terms of rice and soybean grain yields. FDP increased the number of rice grains, resulting in an average improvement of 9% in rice yields across three regions. It also increased the number of soybean pods, resulting in an average increase of 23% in soybean yields across the three regions. The re-sults of this study suggest that the newly developed deep fertilization device can efficiently and rapidly inject fer-tilizer into the soil at depths of 25 to 30 cm. This fertilizer deep placement strategy will be an effective fertilizer ap-plication method used to increase rice and soybean yields, in addition to reducing nitrogen fertilizer use, under con-ventional rice and soybean cultivation conditions. .

광촉매산화법을 이용한 침출수 내 난분해성 물질 제거

홍성창,조성필,김영희 대한환경공학회 1999 대한환경공학회 학술발표논문집 Vol.1999 No.8

유동층연소로에서 압력요동특성치를 이용한 균일입자계 유 무연탄 혼합연소특성 해석

홍성창,차왕석,도동섭,장현태 한국화학공학회 1999 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.37 No.4

내경 0.155m, 높이 2.2m의 유동층연소로에서 유연탄과 무연탄의 혼합연소특성실험을 수행하였다. 본 실험에 사용된 무연탄은 발열량 2,020㎉/㎏으로 저품위 고회분 무연탄이며, 유연탄은 호주산으로 발열량이 6,520㎉/㎏인 저회분 고품위이다. 유동층연소로에서 연소특성을 해석하기 위하여 균일입자의 무연탄과 유연탄을 대상으로 무연탄 혼합비, 석탄 입경비 등을 변수로 실험을 수행하여 압력요동특성치 및 물리화학적 특성치를 이용하여 연소특성을 해석하였다. 유동층연소로에서 혼합석탄의 연소특성 해석은 압력요동특성치의 압력요동의 표준편차, 평균압력, power spectrum density function을 이용하였으며, 압력요동특성치로부터 유동층연소로에서 각각 석탄의 연소영역을 측정할 수 있었다. The characteristics of mixed-firing of an anthracite and a bituminous coal were studied in a fluidized bed combustor(0.155 m-I.D., 2.2 m-height). The used domestic anthracite coal has heating value of 2,010 ㎉/㎏ and the imported high-calorific bituminous coal has heating value of 6,520 ㎉/㎏. The physicochemical analysis and the pressure fluctuation properties were measured to interpret the combustion characteristics in a fluidized bed combustor of uniform particles of mixed anthracite and bituminous coal is a function of the particle size ratio and the anthracite mixing fraction. The combustion characteristics of mixed fuels in a fluidized bed combustor could be interpreted by using standard deviation of pressure fluctuations, mean pressure and power spectrum density function. The different burning region of fluidized bed combustor was measured by the pressure fluctuation properties.

크기가 다른 두 입자계의 초소유동화속도 결정 및 유동화 특성

홍성창,차왕석,도동섭,오광중 한국화학공학회 1992 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.30 No.6

내경이 0.109m인 기-고유동층에서 큰 입자(0.175 ㎜)로 이루어진 계에 크기가 작은 입자(0.359 ㎜, 0.194 ㎜)의 분율을 변화시킴에 따라 나타나는 층분리 현상을 차압전달기로 측정하여 압력요동의 평균압력과 표준 편차를 이용하여 분석하였다. 크기가 작은 입자의 분율에 따른 최소유동화속도 변화를 규명하였고, 또한 층내에서 일어나는 기포의 운동과 입자혼합을 표준편차로서 해석하였다. 실험결과 균일입자로 이루어진 계에서만 적용되었던 압력요동의 표준편차와 유속과의 관계로부터 최소유동화속도를 결정하는 방법은 크기가 다른 두 입자계까지 적용될 수 있음을 알 수 있었으며, 입자크기 차이에 의한 층분리 현상을 압력요동으로 예측할 수 있다. Segregation phenomena occurred from variations of fine particle fractions(0.359 ㎜, 0.194 ㎜) in a 0.109 m ID fluidized bed of coarse particle(0.715 ㎜) were measured by a differential pressure transducer and were analyzed by the standard deviation and mean pressure of pressure fluctuations. The variations of minimum fluidization velocity according to fine particle fractions were investigated and the fluidized bed behaviors such as bubble motion and particle mixing were interpreted by the standard deviation. The method for determination of a minimum fluidization velocity from the linear relationship between standard deviation and air velocity which has been applied only for the uniform sized particle system could also be applied in the binary system. Segregation phenomena occurred by the difference of particle size could also be predicted by the pressure fluctuations.

유동층반응기에서 MeO/NMD를 이용한 저농도 연소가능 오염물의 제거

홍성창,도동섭,박태성,정순관,윤재성 한국화학공학회 1998 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.36 No.5

저농도의 연소가능한 유기화합물을 제거하기 위하여 천연망간광석(NMD: Natural Manganese dioxide)을 기본으로 하여 Pt, Pd를 담지시킨 촉매를 사용하여 CH₄, C_6H_6, C₂H_5OH, CO의 산화반응을 유동층반응기에서 여러 변수에 대해 실험을 수행하였다. 동일한 유속에서 입자크기의 영향은 0.359㎜의 경우가 좋은 효율을 보였으며 층내 기포분율과 반응물의 체류시간의 영향으로 유속이 작고 종횡비가 클수록 산화반응이 우수하였다. 또한 귀금속촉매를 NMD에 담지시킨 경우는 담지시키지 않은 경우보다 낮은 온도에서 유기화합물을 산회시켰고 메탄에 대해서는 PdO/NMD의 경우 실험온도가 Pd의 구조적인 변화를 일으키는 온도이상이므로 NMD보다 산화능력이 떨어졌다. For the removal of combustible pollutant gas at low concentration, the experiment about oxidation of CH₄, C_6H_6, C₂H_5OH, CO, was carried out using platinum, paladium-impregnated NMD(Natural Manganese Dioxide) in the fluidized bed reactor for several variables. At the same flow velocity the effect of particle size on conversion appeared most efficient in the size of 0.359 ㎜. The oxidation was excellent at low flow velocity and large aspect ratio because of the effect of residence time of reactant. Also the, noble metal-impregnated catalyst oxidated VOCs at more low temperature than catalyst without impregnation. For methane oxidation ability of PdO/NMD decreased in the reason that experimental temperature was so high that the structural transformation was caused.

잎들깨 수량과 단백질체 발현에 미치는 UV-B의 영향

홍성창,황선웅,장안철,신평균,장병춘,이철원 한국환경농학회 2006 한국환경농학회지 Vol.25 No.1

An analysis of the relationship between self-study, private tutoring, and self-efficacy on self-regulated learning

홍성창,박윤수 한국교육개발원 2012 KEDI Journal of Educational Policy Vol.9 No.1

This study examines the effect of study behavior that includes self-study and private tutoring; motivation characterized by self-esteem, self-efficacy, and test anxiety; and parental support on self-regulated learning using cross-sectional and longitudinal methods. These relationships were investigated using the Korean Education Longitudinal Study 2005 (KELS, 2005) data, restricting major analyses to students attending general high schools. Results showed that the effect of private tutoring on self-regulated learning was negative, while self-study showed a positive effect. Furthermore, self-study hours seemed to moderate the effect of self-efficacy on self-regulated learning; students that had higher levels of self-study hours also had greater levels of self-regulated learning, whereas students with lower self-study hours had lower levels of self-regulated learning. Results from cross-sectional structural equation models showed that the direct effects of self-esteem and self-efficacy had a significant effect on self-regulated learning. Using a longitudinal analysis based on multilevel random effects regression, the effects of self-esteem and self-efficacy on self-regulated learning were .28 and .17 standardized units, respectively. Test stress also had a minimal yet significant effect of .04 points. The findings from this study show that rather than focusing on private tutoring, efforts to improve self-study, self-esteem, and self-efficacy can lead to an increase in students’ behaviors of self-regulated learning.

바이오차의 시용이 채소 유묘 생장 및 양분 흡수량에 미치는 영향

홍성창,유선영,김경식,이규현,송새눈 한국환경농학회 2020 한국환경농학회지 Vol.39 No.1

. BACKGROUND: Biochar is used in various environmental fields, such as water quality and soil restoration, and affects soil fertility and nutrient cycling. Also, when crops are grown on biochar-applied soil, their characteristics may be affected. Biochar is used especially with commercial vegetable seedlings. METHODS AND RESULTS: The objective of this study was to determine the effects of biochar content in seeding mixes on early growth of lettuce (Lactuca sativa L.), Chinese cabbage (Brassica rapa L.), and red pepper (Capsicum annuum L.). Treatments consisted of a control (0: 10, ratio of biochar to seeding mixes (w/w)), 1: 9 (biochar 10%), 3: 7 (biochar 30%), 5: 5 (biochar 50%), and 7: 3 (biochar 70%). The biochar was made from risk husk and had a C/N ratio of 104. As the mixing ratio of biochar increased, pH increased whereas EC and nitrogen content decreased. The highest phosphorus content was with the treatment of 30% biochar, while there were significant increases in the weight of lettuce seedlings and concentrations of T-N, P2O5, K2O, MgO, and Na with the treatments of 30% and 50% biochar. Although the weight of Chinese cabbage seedlings increased with the treatment of 10% biochar, the increase was not statistically significant. Also, there was an increase in the weight of red pepper seedlings with the treatment of 30% biochar, but the increase was not statistically significant. With increases in the biochar mixing ratio, the K2O concentration of red pepper seedlings increased, but the concentrations of P2O5, CaO, MgO, and Na decreased. It was believed that this was because of absorption inhibition by calcium-phosphate formation in the seeding mixes owing to increased pH. CONCLUSION: In conclusion, adding biochar to seeding mixes is considered to be an important mean for growing healthy vegetable seedlings. More field experiments are needed to verify the effect of biochar on vegetable crop growth over the entire growing season.