기 -고 유동층에서 입자크기가 축방향 압력요동에 미치는 영향

홍성창,오광중,최청송,도동섭 ( Sung Chang Hong,Kwang Joong Oh,Cheong Song Choi,Dong Sup Doh ) 한국화학공학회 1991 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.29 No.2

The pressure fluctuations along the axial distance above the distributor were measured by a differential pressure transducer in a 0.109 m ID fluidized bed of sand particles(0.715, 0.359 and 0.194 mm). The pressure fluctuations were analyzed by the standard deviation and the distribution of power spectrum. The effect of particle size on the pressure fluctuations was investigated with different gas velocities and static bed heights to interpret the fluidized bed behavior such as bubble motion and particle mixing. The amplitude of pressure fluctuation was greatly affected by the particle size and exhibited a maximum value at which the distribution ◎ power spectrum has the most wide and complicate peaks, thus, the most vigorous bubble motion and particle mixing took place at that position in a fluidized bed.

깊이거름주기에 따른 몇 가지 밭작물 재배의 질소비료 사용량 절감과 수량증가 효과

홍성창,이민지,오병욱,이창묵 한국환경농학회 2025 한국환경농학회지 Vol.44 No.-

Nitrogen fertilizers must be applied repeatedly during crop cultivation. The agricultural sector has set a goal of reducing nitrogen fertilizer usage to 23%, from 2022 to 115kg/ha, 2030. Currently, fertilizer is spread on the farming fields and then mixed with the field soil using rotary operations. Deep fertilization treatment entailed injecting basal fertilizer 25-30cm deep into the soil using a deep fertilization device attached to a tractor. For onions, added fertilization using nitrogen fertilizer was omitted once out of three times, and for wheat, once out of two times. For forage corn, added fertilization was reduced by 50%. After crop cultivation, the yield of the deep fertilization treatment significantly increased by 52% for onion, 26% for wheat, and 29% for forage corn, respectively, compared to the conventional surface fertilization treatment. Therefore, deep fertilization could reduce the amount of nitrogen fertilizer used as fertilization by 22% for onions, 25% for wheat, and 25% for forage corn. It was concluded that deep fertilization of basal fertilizer in cultivating onions, wheat, and forage corn can reduce the amount of nitrogen fertilizer used to increase production. The deep fertilization technology is expected to be a low-carbon agricultural technology.

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.

고추밭 고랑 볏짚피복에 의한 양분유출 특성

홍성창,김민경,정구복,소규호 유기성자원학회 2016 유기물자원화 Vol.24 No.1

Excessive application of nutrient supplement on the upland soil may increase the amount of discharge to surrounding water systems. The chemical fertilizer (CF), cow manure compost (CMC), and pig manure compost (PMC) are used as a nutrient supplement for cultivation of red pepper. Rice straws are widely used as a soil covering material in order to reduce weed occurrence, to protect soil moisture, and to supply organic matter in upland soil. This study was conducted to evaluate the furrow covering effect with rice straw on nutrient discharge in upland soil used for red pepper cultivation. The experimental plots of nutrient supplement were consisted of CF, CMC, and PMC and the amount of nutrient application were as recommended amount after soil test for red pepper cultivation. Each nutrient supplement treatment plot has no furrow covering (CFC) as a control and furrow covering with rice straw (FCS), respectively. Furrow covering with rice straw (FCS) of CF treatment and CMC treatment reduced the amount of T-N(total nitrogen) discharge by 1.4 kg ha-1, 2.1 kg ha-1, respectively, compared to control. While the amount of T-P(total phosphorus) discharge of the furrow covering with rice straw of CF, CMC, and PMC increased by 2.1 kg ha-1, 2.1 kg ha-1, and 0.2 kg ha-1, respectively, compared to control. The phosphorus and nitrogen content of straw were 0.4 % and 0.3 % respectively. In addition, in three week the phosphorus was eluted from the straw which soaked in distilled water. Thus, it was assumed that T-P discharging originated from rice straw which applied as a furrow covering material. The furrow covering with rice straw reduced weed occurrence compared to control. But production of fresh red pepper was not influenced significantly by furrow covering with rice straw. In conclusion, excessive furrow covering with rice straw could induce T-P discharge from upland soil used for red pepper cultivation. Further studies are needed to evaluate the appropriate amount of rice straw as a furrow covering material. 농경지에 작물재배를 위한 양분재료의 과다한 투여는 주변 수계로의 양분유출을 증가시킬 수 있다. 고추재배시 사용되는 양분재료는 화학비료, 우분퇴비, 돈분퇴비 등이 대표적이다. 볏짚은 벼 재배의 부산물로 밭 농사에서 잡초발생 억제, 토양수분 보존, 유기물 재료로 널리 사용된다. 본 연구는 노지 고추 재배에서 밭 고랑을 볏짚으로 피복할 때 강우로 발생하는 표면 유출수에 의한 양분유출 특성을 파악하기 위해 수행하였다. 시험구는 양분재료를 기준으로 하여 화학비료, 우분퇴비, 돈분퇴비로 구분하였고 양분투입량은 토양검정 시비량에 준하여 처리하였다. 각각의 시험구는 화학비료 또는 우분퇴비, 돈분퇴비를 시용한 후 볏짚으로 덮은 경우(피복 처리구)와 덮지 않은 경우(무피복구)로 구분하였다. 화학비료 처리구와 우분퇴비 처리구의 볏짚 고랑 피복 처리는 무피복구 보다 T-N (총질소)의 유출이 각각 1.4 kg ha-1, 2.1 kg ha-1 감소하였다. 반면에 화학비료 처리구와 우분퇴비 처리구, 돈분퇴비 처리구의 볏짚고랑 피복 처리는 무피복구 보다 T-P (총인)의 유출이 각각 2.1 kg ha-1, 2.1 kg ha-1, 0.2 kg ha-1 증가하였다. 볏짚은 질소 0.4 %, 인산을 0.3 % 함유하고 있고 증류수에 볏짚을 담근 후 3주일 내에 인산 성분이 유출되므로 T-P의 유출은 고랑을 피복한 볏짚에서 기원한 것으로 추정된다. 무피복구에 비하여 고랑 볏짚 피복구는 잡초발생이 줄었다. 그러나 붉은 고추의 수확량은 무피복구와 볏짚피복구 간에 유의한 차이를 나타내지 않았다. 결론적으로, 고추밭 고랑을 볏짚으로 과다하게 피복하면 T-P의 유출을 유발할 수 있으므로 고랑을 피복하는데 적정한 볏짚량을 산정하기 위한 추가적인 연구가 필요하다고 판단되었다.

질소비료의 심층시비에 의한 논과 밭 토양의 암모니아 배출 억제 효과

홍성창,김민욱,김진호 한국환경농학회 2022 한국환경농학회지 Vol.41 No.4

BACKGROUND: Ammonia gas emitted from nitrogen fertilizers applied in agricultural land is an environmental pollutant that catalyzes the formation of fine particulate matter (PM2.5). A significant portion (12-18%) of nitrogen fertilizer input for crop cultivation is emitted to the atmosphere as ammonia gas, a loss form of nitrogen fertilizer in agricultural land. The widely practiced method for fertilizer use in agricultural fields involves spraying the fertilizers on the surface of farmlands and mixing those with the soils through such means as rotary work. To test the potential reduction of ammonia emission by nitrogen fertilizers from the soil surface, we have added N, P, and K at 2 g each to the glass greenhouse soil, and the ammonia emission was analyzed. METHODS AND RESULTS: The treatment consisted of non-fertilization, surface spray (conventional fertilization), and soil depth spray at 10, 15, 20, 25, and 30 cm. Ammonia was collected using a self-manufactured vertical wind tunnel chamber, and it was quantified by the indophenol-blue method. As a result of analyzing ammonia emission after fertilizer treatments by soil depth, ammonia was emitted by the surface spray treatment immediately after spraying the fertilizer in the paddy soil, with no ammonia emission occurring at a soil depth of 10 cm to 30 cm. In the upland soil, ammonia was emitted by the surface spray treatment after 2 days of treatment, and there was no ammonia emission at a soil depth of 15 cm to 30 cm. Lettuce and Chinese cabbage treated with fertilizer at depths of 20 cm and 30 cm showed increases of fresh weight and nutrient and potassium contents. CONCLUSION(S): In conclusion, rather than the current fertilization method of spraying and mixing the fertilizers on the soil surface, deep placement of the nitrogen fertilizer in the soil at 10 cm or more in paddy fields and 15 cm or more in upland fields was considered as a better fertilization method to reduce ammonia emission.

'학자적 교원' 모형의 개발과 적용

홍성창 한국교원교육학회 2012 한국교원교육연구 Vol.29 No.1

본 연구는 교원들의 지속적 전문성 신장의 노력을 유도하고, 동시에 교직의 위기를 해결하고 위해 새로운 교원 정책의 일관된 틀을 구안하였다. 학문(scholarship)과 학자(scholar)의 특성, 교직 사회의 구성요소 등을 연계하여 '학자적 교원(teacher as scholar)' 모형을 제시하였다. 이는 학자적 전문성(연구, 통합, 적용, 교육), 교원 발달 단계(준비, 입문, 성장, 안정), 경력경로(교수직, 학교경영직, 장학직), 그리고 평가 및 보상 체계(교원 평가, 성과급제, 근무평정 등) 등 네 가지의 요소로 구성되어 있다. 교원 정책의 일관된 틀은 교원의 전문성 개발과 경력경로 개발을 위한 구조를 수립하는데 도움이 될 것이며, 교원정책의 기획과 개발과정에서도 정책의 목표와 지향점을 보다 체계적으로 마련하는데 활용될 수 있을 것이다.

이산화티탄과 UV-B 수준에 따른 벼 생육과 프로테옴 해석

홍성창,신평균,장안철,이기상,이철원,우선희,Hong, Seung-Chang,Shin, Pyung-Gyun,Chang, An-Cheol,Lee, Ki-Sang,Lee, Chul-Won,Woo, Sun-Hee 한국작물학회 2007 한국작물학회지 Vol.52 No.1

Among the photoactive semiconductors such as $TiO_2,\;ZnO,\;Fe_2O_3,\;WO_3,\;and\;CdSe,\;TiO_2$ is the most widely used as photocatalyst in different media, because of its lack of toxicity and stability. In this study, the effects of titanium dioxide were investigated to obtain the information of physiological change in rice plant. Light-adapted Chlorophyll flourescence index decreased and relative electron transport rate of rice leaves was activated by titanium dioxide under $2,400\;{\mu}mol\;m^{-2}\;s^{-1}$ PAR (Photosynthetic active radiation). Relative electron transport rate of rice leaf treated with titanium dioxide 10 ppm was high in order of $2,400\;{\mu}mol\;m^{-2}\;s^{-1}\;PAR,\;2,200\;{\mu}mol\;m^{-2}\;s^{-1}\;PAR,\;450\;{\mu}mol\;m^{-2}\;s^{-1}\;PAR$ and titanium dioxide 10 ppm (45.1%), control (32.4%), diuron 10 ppm (15.3%) under $2,400\;{\mu}mol\;m^{-2}\;s^{-1}\;PAR$. Titanium dioxide increased photosynthesis of the rice leaf under $13.6\;KJ\;m^{-2}\;day^{-1}$ UV-B only. With titanium dioxide 20 ppm, reduced UV-B ($0.15\;KJ\;m^{-2}\;day^{-1}$) intensity changed the induction of proteins and twenty-five proteins were identified. Among them, seventy proteins were up-regulated, four proteins were down-regulated and four proteins were newly synthesized. Function of these proteins was related to photosynthesis (52%), carbohydrate metabolism (4%), stress/defense (8%), secondary metabolism (4%), energy/electron transport (4%), and miscellaneous (28%).

광촉매산화법을 이용한 침출수 내 난분해성 물질 제거

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

(NH₄)₂SO₄-NH₄NO₃-H₂O 계에서 제어결정화를 이용한 (NH₄)₂SO₄의 회수

홍성창 경기대학교부설 산업기술종합연구소 1993 산업기술종합연구소 논문집 Vol.9 No.-

A study was performed on the transient crystal size distribution of the (NH₄)₂SO₄from (NH₄)₂SO₄-NH₄NO₃-H₂O system in a classifying crystallizer, using controlled crystallization method under varioud constant seeding rate. The mathematical model on the controlled crystallization in a classifying crystallizer was established and computer simulation based on the model agreed satisfactorily with experimental results, which means the data on the phase equilibrium and crystallization kinetics parameters used in this study are available. The model proposed in the present study can be used for finding the operating conditions to produce the crystals having uniform size from a system knowing the crystallization parameters.

연구발표논문초록 ( 유동층 ) : 기 - 고 유동층내 압력요동에 관한 연구

홍성창,김동선,최청송 (정),도동섭 (정) ( S . C . Hong,D . S . Kim,C . S . Choi,D . S . Doh ) 한국화학공학회 1988 춘계학술발표회 Vol.- No.-