• Korean Journal of Soil Science and Fertilizer
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• v.45 no.4
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• pp.635-641
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• 2012

The present study evaluated the effect of chitosan on the changes of soil chemical properties, soil microbial population, and yield of red pepper (Capsicum annuum L.) for eco-friendly agriculture in an upland field. We utilized four treatment groups, control, foliar spray, soil drench, and foliar spray + soil drench with chitosan, and analyzed these variations throughout the seven, fourteen, and twenty one days interval. The pH values, organic matter, and available phosphate in the upland soil at the harvesting stage decreased in the chitosan treatment. The populations of bacteria, actinomyces, and fungi in the upland field were increased in plots treated with chitosan. The chlorophyll content of leaves was no significant differences between the control and the chitosan treatments, while calcium content of leaves was significantly higher in the chitosan treatments than in the control. In addition, the nitrogen content of leaves was no significant differences between the foliar spray and the soil drench. The yield of red pepper was significantly higher in the control ($383kg\;10a^{-1}$) than the chitosan treatments and the yield of soil drench with chitosan reached up to 95% of control.

• Applied Chemistry for Engineering
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• v.23 no.1
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• pp.1-7
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• 2012

In this article, I will introduce recent developments of environmental-friendly materials fabricated using atomic layer deposition (ALD). Advantages of ALD include fine control of the thin film thickness and formation of a homogeneous thin fim on complex-structured three-dimensional substrates. Such advantages of ALD can be exploited for fabricating environmental-friendly materials. Porous membranes such as anodic aluminum oxide (AAO) can be used as a substrate for $TiO_2$ coating with a thickness of about 10 nm, and the $TiO_2$-coated AAO can be used as filter of volatile organic compound such as toluene. The unique structural property of AAO in combination with a high adsorption capacity of amorphous $TiO_2$ can be exploited in this case. $TiO_2$ can be also deposited on nanodiamonds and Ni powder, which can be used as photocatalyst for degradation of toluene, and $CO_2$ reforming of methane catalyst, respectively. One can produce structures, in which the substrates are only partially covered by $TiO_2$ domains, and these structures turns out to be catalytically more active than bare substrates, or complete core-shell structures. We show that the ALD can be widely used not only in the semiconductor industry, but also environmental science.

• Applied Chemistry for Engineering
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• v.32 no.2
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• pp.149-156
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• 2021

A kraft recovery boiler produces steam for power generation by the combustion of black liquor from the kraft pulping process. Since saturated steam became superheated in a superheater above the furnace, it is important to increase the heat exchange efficiency for the superheated steam production and power generation. A nose arch at the bottom of the superheater is important for blocking radiation from the furnace which causes corrosion of the superheater. But the nose arch is the main reason for creating a recirculation region and then decreasing the heat exchange efficiency by holding cold flue gas after the heat transfer to saturated steam. In this study, the size of recirculation region and the temperature of flue gas at the outlet were analyzed by the nose arch structure using computational fluid dynamics (CFD). As a result, when the nose arch angle changed from 106.5° (case 1) to 150° (case4), the recirculation region of flue gas decreased and the heat exchange efficiency between the flue gas and the steam increased by 10.3%.

• Applied Chemistry for Engineering
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• v.31 no.6
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• pp.596-602
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• 2020

Blending process of adhesive production has a cooling process to cool down the temperature of the solution which was heated up to 76 ℃ with a mineral insulated (MI) cable by 30 ℃ at room temperature. Using a MI cable in the adhesive production process makes the production inefficient because it takes about 10 h for the cooling process. If a jacketed vessel is used instead of the MI cable, it would shorten the cooling downtime without any additional cooling system by using cold water. However, there are various types of jacketed vessels, and thus the most suitable type should be found before set up. In this study, we designed the optimized jacketed vessel for the adhesive production process by calculating the cooling downtime, which impacts production efficiency, as a function of the jacket types using computational fluid dynamics. As a result, the cooling performance of the plain jacket was 32.7% superior to that of the half-pipe coil jacket with the same height. In addition, the plain jacket with 60% spiral baffle reduced the cooling downtime and operating time by 80.4% and 25.1%, respectively.

• Applied Chemistry for Engineering
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• v.34 no.5
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• pp.522-528
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• 2023

In this work, adhesive tapes were prepared for the dicing process in semiconductor manufacturing. Compounds with different numbers of photoreactive groups (f = 1 to 3) were synthesized and incorporated into acrylic copolymers to formulate UV-curable acrylic adhesives. Structural confirmation of the synthesized photoreactive compounds (f = 2 or 3) was performed using nuclear magnetic resonance (NMR) spectroscopy. The introduction of the photoreactive compounds into the acrylic adhesive was accomplished by urethane reactions, and the successful synthesis of the UV-curable acrylic adhesive was verified by Fourier transform infrared (FT-IR) measurements. To evaluate the performance of the adhesive, the peel strength was evaluated before and after UV irradiation using a silicon wafer as a substrate. The adhesive exhibited high peel strength (~2000 gf/25 mm) before UV exposure, which was significantly reduced (~5 gf/25 mm) after UV exposure. Interestingly, the adhesive containing multifunctional photoreactive compounds showed the most significant reduction in peel strength. In addition, surface residue measurements by field emission scanning electron microscopy (FE-SEM) showed minimal surface residue (~0.2%) after UV exposure. Overall, these results contribute to the understanding of the behavior of UV-curable acrylic adhesives and pave the way for potential applications in semiconductor manufacturing processes.

• Korean Journal of Environmental Agriculture
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• v.32 no.4
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• pp.338-342
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• 2013

BACKGROUND: Two Field tests were conducted at Buan and Yangpyung in 2012 and 2013 to confirm controlling effect of mulberry popcorn disease and mulberry Sucker pests which are becoming serious in mass cultivation area of eco-friendly farming mulberry. METHODS AND RESULTS: As the treatments, 4 Natural products and 3 microbials were applied and 4 mulching materials were used. On the prevent effect of mulberry popcorn disease(Sclerotinia shiraiana) by using mulching materials, nonwoven fabric mulching showed worse effect than non-mulched treatment plot. Moreover, rice straw mulching showed significantly worse effect compare to nonwoven fabric and herb mulching treatments. Natural plant extracts and microbials showed 40~65% control value in 2013, which is little bit worse than 2012 results. On the control effect of mulberry Sucker(Amomoneura mori), organic products which combined with neem, sophora and derris showed excellent result as similar control level of Thiophanate-methyl. It means the chemical products can be replaced with organic product. CONCLUSION(S): According to the 2 years studied results, integrate eco-friendly farming measures are recommended for control of mulberry popcorn disease, because any single method is seemed not sufficient enough. However, natural plant extracts mixture is recommended as a product to control of mulberry Sucker.

• Proceedings of the Korean Society of Organic Agriculture Conference
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• 2009.12a
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• pp.309-309
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• 2009

국내외 환경문제와 관련하여 농업환경보전 및 안전한 먹거리에 대한 소비자의 요구가 커지면서 친환경농업에 대한 관심이 높이지고 있다. 친환경농업은 화학비료와 농약의 사용을 양분종합관리 및 병해충종합관리등을 통해 저투입하는 농법과 화학비료와 농약의 대체 농자재를 사용하는 유기농법으로 나누어져 있다. 대체 농자재는 목초액, 키토산 등 시판되는 자재를 비롯하여 천혜녹즙, 한방영양제, 아미노산액비 등과 같이 농가를 중심으로 자가 제조되어 활용되고 있는 것이 특징이다. 그러나 대부분 효능이 제대로 검증되지 않고 임의로 사용되고 있기 때문에 본 연구는 농가 자가제조 유기농액비의 미생물학적 특성을 구명하여 유기농 액비의 농업적 활용 제고를 위한 표준화를 확립하기 위해 수행하였다. 농가자가 제조 유기농액비는 성환과 제주에서 5점을 수집하여 액비의 화학성과 미생물상을 비교하였다. 액비 제조시 종균으로 사용되고 있는 부엽토를 5지역에서 채취하여 세균군집의 차이를 보기위해 denaturing gradient gel electrophoresis (DGGE)를 수행하여 분석하였다. 주요 결과를 요약하면 수집된 액비의 화학성 분석결과, pH는 3.3~4.3로 강한 산성을 나타났으며 EC는 $32.8dS{\cdot}m^{-1}{\sim}552.33dS{\cdot}m^{-1}$ 이었다. 수집된 액비내 미생물상을 조사한 결과, 세균과 방선균은 존재하였지만 사상균은 검출되지 않았다 또한 성환에서 수집된 액비로부터 세균을 분리하여 16S rRNA 염기서열을 분석한 결과, 대부분 Bacillus속으로 95%이상의 높은 유사성을 갖는 것으로 나타났다. 액비 발효 시 종균으로 사용되고 있는 부엽토의 미생물상을 조사한 결과, 지역에 따라 세균은 0.8~$110{\times}10^5cfu{\cdot}g^{-1}$, 방선균은 1.0~$10.9{\times}10^4cfu{\cdot}g^{-1}$, 그리고 사상균은 2.6~$64{\times}10^3cfu{\cdot}g^{-1}$의 균수를 보였다. 부엽토간의 세균군집의 차이를 비교하기 위해 DGGE를 수행한 결과, gel 상에서 다양한 위치의 밴드를 확인할 수 있으며, 부엽토별로 공통적 및 특이적 밴드를 확인할 수 있었다.

• Journal of the Korean GEO-environmental Society
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• v.9 no.5
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• pp.37-43
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• 2008

Inorganic injection material, which is one of the ground improvement materials, consists of cement accelerator and inorganic micro particle. The inorganic injection material is known to overcome the major limitations of water glass type improvement materials, which are leaching and accompanying strength loss. The inorganic injection material is superior in durability and strength, and environmentally friendly since leaching is prevented. In this study, the effectiveness and environment-friendliness of the MIS(Micro Injection-process System) using the inorganic injection material is compared to SGR, which uses the water glass. The performed tests were unconfined compression test, chemical resistance test, and fish poison test. The unconfined compression tests showed that the MIS results in 1.7 times higher 28 day strength compared to the SGR. In addition, the strength continually increased with time for the MIS, while it decreased for the SGR. The chemical resistance tests indicated that the rate of change in length using the MIS is 10~25 times smaller than when using the SGR. The fish poison test proved that MIS was more environmentally friendly. The analysis of chemical ingredients of leached showed that the amount of $Cr^{6+}$, Pb and Si leached from the MIS is less compared to the SGR. Accordingly, the MIS grout is more high-strength than existing SGR grout. It is excellent in shortening of construction period, structural stability of foundation and environmentally friendly. So, it is considered that it has not little the problem about groundwater pollution.

• Journal of the Korea Organic Resources Recycling Association
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• v.30 no.2
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• pp.5-15
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• 2022

In this study, heated tobacco biomass was prepared as an active material for supercapacitor device. Retrieved tobacco leaf from the heated tobacco was carbonized at various temperature(800/850/950℃). Carbonized tobacco leaf material synthesized at 850℃ exhibited the highest C/O ratio, indicating the finest carbon quality. In addition, polypyrrole was coated onto the carbonized leaf material for increasing the electrochemical performance via low-temperature polymerization method. As-synthesized carbonized leaf material at 850℃(CTL-850)-based electrode and polypyrrole-coated carbonized leaf material(CTL-850/PPy)-based electrode displayed outstanding specific capacitances of 100.2 and 155.3F g^-1 at 1 A g^-1 with opertaing window of -1.0V and 1.0V. Asymmetric supercapacitor device, assembled with CTL-850 as the negative electrode and CTL-850/PPy as the positive electrode, manifested specific capacitance of 31.1F g^-1(@1 A g^-1) with widened operating voltage window of 2.0V. Moreover, as-prepared asymmetric supercapacitor device was able to lighten up the RED Led (1.8V), suggesting the high capacitance and extension of operating voltage window. The result of this research may help to pave the new possibility toward preparing the effective energy storage device material recycling the biomass.

• Korean Chemical Engineering Research
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• v.45 no.2
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• pp.133-142
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• 2007

As the environmental pollution caused by excessive uses of chemical fertilizers and pesticides is aggravated, organic farming using pasture and livestock manure is gaining an increased necessity. The application rate of the organic farming materials to the field is determined as a function of crops and soil types, weather and cultivation surroundings. When livestock manure is used for organic farming materials, the volatilization of ammonia from field-spread animal manure is a major source of atmospheric pollution and leads to a significant reduction in the fertilizer value of the manure. Therefore, an ammonia emission model should be presented to reduce the ammonia emission and to know appropriate application rate of manure. In this study, the ammonia emission rate from field-applied pig manure is predicted using an artificial neural network (ANN) method, where the Michaelis-Menten equation is employed for the ammonia emission rate model. Two model parameters (total loss of ammonia emission rate and time to reach the half of the total emission rate) of the model are predicted using a feedforward-backpropagation ANN on the basis of the ALFAM (Ammonia Loss from Field-applied Animal Manure) database in Europe. The relative importance among 15 input variables influencing ammonia loss is identified using the weight partitioning method. As a result, the ammonia emission is influenced mush by the weather and the manure state.